center of excellence in wireless and information technology€¦ · robotics, social networks, data...

CEWIT Research

Center of Excellence in Wireless and Information Technology

www.cewit.org

Network Technologies Research in the Network Technologies Division includes but isnot limited to network design, modeling, implementation andtesting of various forms of wireless ad hoc, sensor networks andmesh networks, protocol design for wireless and mobile net-works, vehicular networks, network planning and management,network security, location management and tracking, and physical layer aspects such as MIMO. The activity in networkingtechnologies focuses on both basic and applied research lead-ing to commercialization.

Software Systems Our Software Systems Division includes a number of interna-tionally recognized research faculty from the University andhundreds of Ph.D. students working to advance software tech-nologies. The research activities in Software Systems are quiteexhaustive and include but are not limited to cyber-security,testing and verification, computer games, simulation and ren-dering, 3D visualization, cryptography, data modeling, algo-rithms, operating systems, geometric modeling, news and bloganalysis, quality assurance, secure data management, virtualreality, file systems, augmented reality, bioinformatics, data min-ing and computational biology.

Communications and Devices Our Communications and Devices Division encompassesresearch in digital signal processing, new sensor and RFIDSystems, optical packet interconnects, wireless/mobile communi-cations, image processing, micromachining, superconductorelectronics, trusted hardware devices and spectrum sharing.

Systems and Infrastructure Our Systems and Infrastructure Division is not only advancingresearch in related fields, but is also creating solutions and systems for commercialization. The work in this division includesmobile technologies for social impact, image processing, robotics, social networks, data visualization and visual analytics,applications of sensor networks and signal processing, learning,secure storage, service oriented architectures, fault diagnosis,web information systems, reconfigurable hardware and regulatory compliance.

Medical DivisionOur Medical Division uses wireless and IT technologies toenhance the productivity and quality of healthcare. The research in this division includes but is not limited to computer aided detection of colon cancer, prostate imaging,detection of atrial fibrillation, non-invasive and trans-cutaneousimaging, brain imaging and modeling, potassium monitoring,robotic biopsy, medical error detection, computer-aided medical diagnosis, virtual colonoscopy, computational biology,wireless health monitoring, 3D computed tomography andRFID based medical applications.

2 From the Director

Wireless and Information Technology Research

Stony Brook University is an affirmative action/equal opportunity educator and employer. This publication can be made available in an alternative format upon request. © 2009 Stony Brook University

The Center of Excellence in Wireless & Information Technology, (CEWIT) at Stony Brook University is a leading U.S. research institutionfocusing on cutting edge research and wireless and information technology. Since its inception the extraordinary scope of the Center’sactivities have encompassed all major IT research areas. The cooperation between the center and business enterprises continues to drivecommercialization of research and economic growth. This publication describes the research activities of our Five Divisions.

Our interdisciplinary research efforts are supported by federal and state agencies and business enterprises and range across the broad spectrum of wireless and information technologies. The projects described in this brochure are a sample representation of the depth andbreadth of CEWIT’s commitment to advance scientific knowledge and help usher a generation of new technologies that will lead to economic growth worldwide.

Yacov Shamash, Vice President for Economic Development, Gail S. Habicht, Vice President for Research Dean of the College of Engineering and Applied Science

Satya Sharma, Executive Director, CEWIT Arie Kaufman, Chief Scientist, CEWIT

CEWIT 3

Network TechnologiesHardware Aware Software Testbed Environment for Target Specific Cross Layer Network Design ...................................................5

Cooperative Relay Communications in Mesh Networks...................................5

Self Learning Real Time Location Tracking in Wireless Sensor Networks ........5

Cellular and Mobile Networks Security ............................................................6

Data-Driven Mobility Modeling for Wireless Networks.....................................6

Information Dissemination in Mobile Wireless Peer-to-Peer Networks ............6

Applied Cryptography for Networked Contexts ................................................6

A Measurement-Driven Approach for the Design of Wireless Mesh Networks .................................................................6

Accessing Urban WiFi Networks from Moving Vehicles....................................7

Adaptive Exploitation of Multiplexing and Diversity in Heterogeneous MIMO Ad Hoc Networks..........................................................7

Sensor Network Applications and Services .....................................................8

Network Planning and Real-time Automated Management System ................8

Cooperative Resource Management for IP-based Radio Access Network .......8

Geometric Algorithms for Wireless Sensor Networks ......................................9

Computational Geometry for Network Optimization ........................................9

Self-powered Wireless Sensor Technology for Monitoring the Health of Electric Power Transmission Systems ......................................10

A Miniaturized Robotic Testbed for Development, Testing, and Evaluation of Protocols on Multi-Hop Wireless Networks...............................10

Scalable Monitoring and Discovery of Enterprise Networks...........................11

Airborne Video Sensor Networks for Surveillance .........................................11

Desynchronizaton in Wireless Ad-hoc Sensor Networks................................11

Software SystemsLattice Simulation and Rendering..................................................................12

Testing and Verification of Concurrent Software ............................................12

Cryptanalysis and Cryptographic Design .......................................................12

Micropayment and Digital Cash Systems ......................................................12

From Rules to Analysis Algorithms with Time and Space Guarantees ...........13

Runtime Monitoring and Model Checking for High-Confidence Systems Software .........................................................................................13

Operating Support for Application-Level File-System Transactions................13

News and Blog Analysis ................................................................................14

Instructional Technologies: the Future of Teaching and Learning...................14

Content-Based Control for Blogs and Social Networks..................................14

Parallel Computing Algorithms for Scientific Computing................................15

Cooperative Worm Defense ...........................................................................15

Interdependent Security Models for Cyber Defense ......................................15

An Update-Aware Disk I/O System and Its Applications ................................16

SecureWORM: Strong Regulatory Compliant Storage....................................16

Clarity and Efficiency in Design .....................................................................16

File System Tracing, Replaying, Profiling and Analysis on HEC Systems........17

Survivable Software ......................................................................................17

Authenticating Reality....................................................................................17

Evidence-Based Utilization Management of NYS Medicaid Program .............18

Shift-Variant Deblurring .................................................................................18

Feather-Weight Virtual Machine.....................................................................18

Secure Document Management ...................................................................19

Patient Flow Management ............................................................................19

Representative Image Selection from Web-Based Photo Collections.............19

Invariant Rules for Software Producibility and Assurance .............................20

A Polymorphic Emulation Approach to Software Obfuscation ........................20

General-Purpose Computation on Graphics Processing Units........................20

Intelligent Deformable Models .......................................................................21

Multivariate Simplex Splines for Data Modeling and Visualization .................21

Shape Space and Shape Matching using Differential and Algebro-geometric Approaches ....................................................................22

Conformal Geometry Applied to Shape Analysis and Geometric Modeling ...............................................................................22

Discrete Curvature Flows on Graphics and Visualization ...............................23

Computing Geometric Structures of 3-Manifolds .........................................23

Communications and DevicesTransport of Droplets and Bubbles in Microfluidic Networks ........................24

High-level Synthesis and Optimization of Analog and Mixed-signal Systems ............................................................................24

Miniature Acoustic Source Localization Sensor Node ....................................25

Automated Design of Reconfigurable (Programmable) Sensing Frontends....25

Smart Radiation Detection Readout IC...........................................................25

Mobile Data Gathering in Wireless Sensor Networks.....................................26

Ultra Low Latency Optical Packet Interconnects...........................................26

Passivation of GaSb- surface by Micromachining and Formation of a Native Oxide ..........................................................................27

A System Infrastructure for Scalable and Robust Wireless Communications and Services ...........................................28

Superconductor Electronics Based on RSFQ .................................................28

Forward-Scattered Signal-Based System for Detection of UHECR.................28

A Flexible Network Infrastructure for Versatile Wireless Communications .....29

Multi-View Stereo Camera Systems for 3D Imaging......................................29

Development of a New RFID System ............................................................29

Digital Imaging for New Generation Cameras................................................30

The Stony Brook Trusted Hardware Lab ........................................................30

Market-Driven Approach to Dynamic Spectrum Sharing ...............................30

Enabling Interoperable Public Safety Radio Communications .......................30

Energy Efficiency in Wireless Sensor Networks .............................................31

Reconfigurable Architecture for DSP Applications..........................................31

Systems and InfrastructureIntelligent Mobile Technologies for Social Impact ..........................................32

Combining Information from Words and Pictures ..........................................32

On New Stochastic Approaches for Solving Forward and Backward Problems of Biochemical Networks ..............................................32

Theory of Generalized Particle Filtering .........................................................33

Multi-robot Exploration and Deployment .......................................................33

Target Tracking..............................................................................................33

High-performance Rule Engine for Intelligent Web Information Systems.......34

A Framework for Analyzing and Ensuring Trust in Service-Oriented Architectures......................................................................34

Model-Driven Visual Analytics........................................................................34

Plume Modeling Simulation and Visualization................................................35

Visual Simulation of Thermal Fluid Dynamics in a Water Reactor..................35

cDB: Strong Regulatory Compliant Databases...............................................35

NS3: Networked Secure Searchable Storage with Privacy and Correctness................................................................................36

Deductive Framework for Programming Sensor Networks ...........................36

The Impact of Storage Software and Aging on Power Consumption..............37

Wireless Utility Monitoring and Control and for Efficient Energy Utilization....37

Consensus Protocols – Analysis, Simulations, and Implementation...............37

Declarative Framework for Learning and Evaluating Probabilistic Models of Events in Sensor Networks .....................38

Geometric Algorithms for Air Traffic Management .........................................38

A Multi-Semantic, Goal-Oriented Programming Paradigm for DependableOperation of Massively Distributed Reconfigurable Systems .........................39

Sensors and Sensor Networks Applications on Complex System Using Intelligent Fault Detection and Diagnosis (iFDD) ..................................39

Scheduling for Parallel and Distributed Systems ...........................................39

High-Dimensional Visualization Made Accessible Using Illustrative Techniques .........................................................................40

On Networks and Behavior: A Computational Game Theoretic Approach to the Study of Influence ..............................................................40

Medical Development of Laser Scanning Optical Imaging System for Noninvasive and in vivo Trans-cutaneous Imaging at Subcelular Resolutions ...................41

Potassium Monitoring....................................................................................41

Computer Aided Detection of Colon Cancer...................................................42

Computer-Aided Diagnosis System for Fast, Accurate and Remote Evaluation of Acute Chest Pain .................................................42

Integrated Modeling and Learning of Multimodality DataAcross Subjects for Brain Disorder Study......................................................43

Computer Games and Virtual Reality Environment for Rehabilitation ............43

Model-Based Learning, Analysis and Control of Excitable Tissue ..................44

Algorithms for Detection of Atrial Fibrillation..................................................45

Biomedical Contact Interface Diagnosis Based on Nonlinear Viscoelastic Model .........................................................................45

Prostate Imaging ...........................................................................................46

Robotic Needle Biopsy...................................................................................46

Virtual Colonoscopy .......................................................................................46

Computational Methods for Discovering Virulent Proteins and Bio-engineered Threats ..........................................................................47

Rapid-CT: Real-Time 3D Computed Tomographic Reconstruction UsingCommodity Graphics Hardware.....................................................................47

Emergency Department Error Detection System (EEDS) ................................47

A Radio Frequency Identification System for Prevention of Denture Loss in Long Term Care Facilities ................................................48

Self-Powered Health Monitoring System .......................................................48

Polymers in Potassium Ion Selective Electrodes............................................49

Investigation into Insertion of RFID Tag Inside a Pill.......................................49

Combined Near and Far Field UHF RFID Based Specimen Inventory and Tracking System......................................................................50

Staff and Researchers Leadership and Researchers .........................................................................51

4 Contents

Hardware AwareSoftware TestbedEnvironment for TargetSpecific Cross LayerNetwork Design

Sangjin Hong

As many of application specific networkshave gained popularity in the last few years,the complexity of network applications andprotocols as well as network nodes such asrouters is increasing in a rapid pace. More-over, networks are constantly evolving due tochanges in application specific constraintssuch as energy efficiency, computation com-plexity, and network specifications. To copewith such advances, we strongly believe aneffective and accurate cross layer joint opti-mization is extremely critical. Conventionalnetwork optimization strictly considers asoftware perspective without the effects ofhardware characteristics. However, the hard-ware capability is becoming a limiting factoras network specific algorithms and applica-tions are getting more and more complex. Inorder to understand such impacts of thehardware capability such as speed, complex-ity and power consumption on the overallnetwork performance, it is necessary to inte-grate hardware features within a network-level simulation model. Many operationalnetwork simulation and modeling paradigmsalready exist. However, all of these simula-tors are not capable of capturing hardwareaspects in the simulation model such thatalgorithms, applications, and hardware inter-dependencies cannot be exploited for optimization. Because of these problems,many optimizations rely on empirical datawhich can significantly deviate from theactual deployment. We are currently imple-menting a new accurate software testbedenvironment. The proposed testbed environ-ment will provide an accurate and flexiblenetwork simulation environment while effec-tively modeling and optimizing the network through joint software/hardwareoptimization. (MKE)

Cooperative RelayCommunications inMesh Networks

Petar M. Djuric

The topology of wireless networks is movingfrom the classical concept of a central stationand several subscriber stations communicat-ing with it to a concept where the hierarchyof the wireless stations is diluted and whereall the stations (nodes) contribute to thetransport of information. The new standardIEEE 802.16 adopts a mesh mode in itsMedia Access Control (MAC) layer. In thismode, the subscriber stations communicateamong themselves. Other wireless systemsthat adopt a mesh mode of communicationare the sensor networks. The standard IEEE802.15.4 regulates their specifications andoperation and it considers a peer-to-peertopology that allows the formation of meshnetworks. In a mesh network, there arenodes that act as relay nodes and where thefinal destination node is reached after sever-al wireless hops. In this project we study theperformance of mesh networks with varioustopologies and in different scenarios. Thereare two main strategies when dealing withrelaying nodes: one is amplify-and-forward(AF) and the other decode-and-forward (DF).The latter alternative has several advantagesrelated with implementation including thatthe radio-frequency stages of the nodes arenot conditioned by the relaying and, at leastin principle, it is easier to incorporate it insystems with mixed mode of operation. Inthis project we deal with the DF scheme. Inparticular, we work with a system withuncoded DF streams and symbol-by-symboldemodulators. This project is carried out incollaboration with Dr. Angel Bravo from theUniversity Carlos III, Leganes, Madrid, Spain.(Ministry of Science and Innovation, Spain)

Self Learning Real TimeLocation Tracking inWireless SensorNetworks

Jacob Sharony

Real Time Location Systems (RTLS) havemany applications in various vertical mar-kets, e.g., healthcare, manufacturing, logis-tics, etc. These systems are used for assetinventory and location tracking, essentiallyenabling total “enterprise visibility,” byanswering the following questions: What dowe have? How many do we have? Where isit? and What is its status? Since many enter-prises have already installed WiFi data net-works, it is desirable to leverage the existinginfrastructure for location tracking using the easy to implement and cost-effectiveReceived Signal Strength Indicator (RSSI)method. However, the accuracy of currentRSSI-based WiFi RTLS is several meters ormore when deployed indoors depending onthe density of the installed Access Points(AP’s). Achieving higher accuracy (e.g., sub-meter) will require denser deployment ofAP’s resulting in impractical and cost-prohib-itive solution. In addition, due to the frequentchanges in the environment the RF channelcharacteristics are also changing and hencerequiring frequent RF site-surveys, which arecostly and time consuming. Using low-cost,battery operated devices, e.g., ultra-lowpower WiFi, ZigBee, RFID, etc. could alleviatethis limitation resulting in accurate and cost-effective solutions. We have developed anautomated self-learning location estimationmethod that takes into account the dynamicchanges in the RF environment resulting inhigh accuracy location tracking. We testedempirically the method using low cost bat-tery-operated ZigBee modules and achievedsub-meter accuracy. (CEWIT)

CEWIT 5

Network Technologies

Cellular and MobileNetworks Security

Radu Sion

In this project we are designing and buildinga security protocol and infrastructure for mo-dern, highly mobile environments and hard-ware. One example of this is a personalDigital Rights Management suite. In the pro-cess of content sharing, users of such tech-nology will be able to assert and control dissemination rights of produced content as it traverses remote, possibly untrustedconsumer environments. At the content con-sumer side, associated mechanisms forsecure DRM enforcement will need to beintegrated with methods for code authentica-tion and mal-ware detection. (Motorola)

Data-Driven MobilityModeling for WirelessNetworks

Jennifer L. Wong and Jie Gao

Advancements in wireless technology haveled to an abundance of mobile wirelessdevices. Mobility models are a fundamentalcomponent in the development of wirelessmobile networks. The current mechanism forevaluation of mobile protocols and applica-tions is based on random mobile movement.Random movement is simple to implement,but highly non-realistic and may introduceartifacts in the evaluation. In this project thefocus is on (a) the collection and manage-ment of real-life data traces of movementand (b) the development of a simulation envi-ronment where movement is statisticallysimilar to the real-life data. We propose thecollection of GPS data traces for the creationof mobility benchmark sets which are repre-sentative of typical movement(s) of a mobileentity or group of entities. In addition, the goalis to create a simulation environment whichwill generate user mobility patterns statisti-cally similar to a collected benchmark set.(Funded internally)

InformationDissemination in MobileWireless Peer-to-PeerNetworks

Jennifer L. Wong and Jie Gao

Mobile internet devices give users the abilityto have constant connections to news, wea-ther, e-mail, friends, etc. However, the com-munication needs of mobile users are oftenmuch more diverse and context and locality-aware — that is, the information to be deliv-ered to a user is highly influenced by thespatial and temporal context under which theuser resides.

The goal of this project is to develop solu-tions to enable smooth and seamless con-nectivity and locality-based data services ina highly mobile, highly heterogeneous peer-to-peer environment. Currently, we aredeveloping a basic prototype application formobile phones which enables users to sub-scribe and distribute locality and contextualinformation to neighboring users. We utilizeBluetooth connections between the mobilephones to create a dynamic peer-to-peernetwork. In the future we aim to study andaddress issues such as energy efficiency,information flow, privacy, and social impacts.(Funded internally)

Applied Cryptographyfor NetworkedContexts

Radu Sion

In the Network Security and Applied Crypto-graphy Laboratory we are developing crypto-graphically secure protocols with an empha-sis on the practicality of their application innetworks and systems. (Funded Internally)

A Measurement-DrivenApproach for theDesign of WirelessMesh Networks

Samir R. Das

Wireless mesh networks are becoming pop-ular for ubiquitous and low-cost wirelessbroadband connectivity. However, they sufferfrom serious interference problems whichlimit their capacity. We use TDMA schedulingto address these performance problems. Weuse a SINR-based physical interferencemodeling for realism, and various forms ofdiversities - such as transmit power control,directional antennas, multiple channels, andrates - to maximize performance. We alsointroduce a measurement-based modelingtechnique to make the physical interferencemodeling practical. We support these innova-tions by experimental studies using 802.11PHY-layer hardware. Our goal is developing acomplete set of algorithms, protocols, andsystem solutions that target “managed”mesh networks. The protocol solutionsinclude the routing layer and below, and arecompatible with existing Inter-networkingprotocols for the transport layer and up. Theproject's intellectual merit has the followingcomponents:

1) New protocols for TDMA scheduling withdiversity and physical interference model-ing,

2) integration of scheduling with routing,

3) measurement-based modeling of physicalinterference, and

4) simulation modeling and testbed experi-ments to support protocol innovations.(NSF, NEC Labs.)

6 Network Technologies

Accessing Urban WiFi Networks fromMoving Vehicles

Samir R. Das

Recently, the “connected car” concept isgaining ground where the car is a node in awireless network, enabling many applica-tions, such as safety, infotainment and vari-ous forms of monitoring. However, if highbandwidth data transfer is desired from a car– for example, downloads from the Internet,cellular data networks are the only availablechoice at this time. But cellular data isexpensive. It is also unclear whether the cel-lular data networks will have adequate band-width if all cars are connected this way. Suchdata transfer may not be limited to justInternet access. It can also include inter-vehicle communication for safety applica-tions, sensor data upload for monitoringapplications, download data for real-timenavigation, etc. Possibilities are limitless.

To address the bandwidth challenge, we arepursuing technologies to access the WiFiaccess points (AP) in urban areas from amoving car. These APs could be in publichotspots, metro WiFi networks, or even inpeople’s homes subscribed to a communitynetwork such as FON. No new deployment isneeded. The idea is to take advantage of thealready existing high bandwidth WiFi con-nections in dense urban areas without pay-ing any spectrum cost.

However, there are significant challenges.WiFi range is short. This means frequent dis-connections and reconnections. Also, therecould be pockets where no AP is available toconnect. Recently, our research group hasdeveloped an architecture, called MobiSteer,that uses a steerable beam directionalantenna with a WiFi client node on a movingvehicle. MobiSteer uses novel beam steeringand AP selection algorithms to improve thequality and duration of the connectivitybetween the moving vehicle and roadsideAPs. This facilitates high quality Internetaccess. MobiSteer has also been found to besuccessful in maintaining high quality directcommunication between two moving vehi-cles, even when they are more than a kilo-meter apart. Thus, a fleet of cars can main-tain an ad hoc network amongst themselveswithout any external networking support.

In addition to MobiSteer, we are also workingon predictive methods to improve handoffs.This includes use of “war-driving” to collectsignal strength data and using this collectedinformation to design new handoff strate-gies. We are also exploring use of pre-fetch-ing at APs to improve download speeds.(Funded Internally)

Adaptive Exploitation of Multiplexing and Diversity inHeterogeneous MIMOAd Hoc Networks

Xin Wang

As an effective technology to improve relia-bility and increase data rate, MIMO is nowconsidered in ad hoc networks. However, it isimportant and challenging to develop effi-cient schemes to coordinate node transmis-sions in a MIMO-based ad hoc network. Inthis work, we propose a MAC protocol andscheduling schemes to adaptively exploitboth diversity and multiplexing to coordinatetransmissions in heterogeneous MIMO adhoc networks, where nodes have differentantenna array sizes. To improve the networkthroughput and transmission quality, ourscheduling schemes concurrently considerantenna array size, traffic demand, servicerequirements, multiuser diversity and chan-nel condition. We extend the conventionalpoint-to-point MIMO link to a many-to-manymultiuser case, so that neighboring nodescan take advantage of the meshed networktopology to cooperate in transmission andform a virtual MIMO array. In order to allevi-ate the constraints caused by node hetero-geneity, the varied decoding capacities ofnodes are differentiated and transmissionsare adaptively grouped towards differentnode categories. In each transmission dura-tion, transmitter nodes and their antennasets are selected opportunistically to exploitthe multiuser diversity and selection diversi-ty to a large degree. Through priority-awarescheduling, the scheme also supports differ-ent service types while reducing transmis-sion delay and ensuring fairness amongnodes. Our scheduling schemes are cross-layer and consider physical channel condi-tion and transmission power in MAC design.(CEWIT)

CEWIT 7

Sensor NetworkApplications andServices

Xin Wang

Sensor networking envisions a ubiquitouscomputing future in which scattered smartsensors combine to form dynamic, ad hoc,low power, and self-configurable wirelessnetworks capable of monitoring their exter-nal environments and relaying their data to asmart space infrastructure. These sensornetworks will operate in a variety of environ-ments, including home, office, and military,and will assist in such activities as locatingand identifying people, monitoring room andenvironment conditions indoors, as well astracking the motion of vehicles and providingsurveillance monitoring outdoors. Resourcessuch as power, processing speed and mem-ory are highly constrained in sensor net-works. The goal of our research is to designlarge, power efficient sensor networks toenable various applications and services. Wealso exploit the use of RFID technique tofacilitate the capturing of context informa-tion, and to enable more comprehensiveapplications and services. We will develop asystem architecture across MAC, networkand application layer to optimize the per-formance of a large sensor network by tak-ing into account the interactions and trade-offs between different design objectives. Oursystem includes a two-level node activityscheduling scheme for energy conservation,and a scenario aware data disseminationscheme to efficiently distribute query andevent data, and handle inquirer and targetmobility. (NSF)

Network Planning andReal-time AutomatedManagement System

Xin Wang

Mobile ad-hoc networking is a technologythat offers great value to warfighters andcivilian first responders. It promises self-forming, self-healing distributed networkingthat is ideally suited to the constantly chang-ing environments of the battlefield and thedisaster relief site. However, the reality ofmobile ad-hoc networks (MANETs) has yet tocome level with the promises. The networkplanning does not yet enable planners to useMANETs as a connectivity extender, and todate MANETs are not reliable enough ineither connectivity or throughput to reliablycarry mission-critical information. This proj-ect intends to develop a management sys-tem for MANET with the following objectives:

1) Define recommended tactics, techniques,and procedures for planning for MANET;

2) Define capabilities that allow MANETs tomove from self-forming to self-manage-ment;

3) Define an architecture that integrates self-planning MANETs into existing networkmanagement tools for both planning andmanagement.

We will design a backbone constructionalgorithm for reliable and fast informationtransmission, develop cost models for effi-cient topology control and QoS support, anddistributed schemes for network manage-ment, admission control, flow control, andrate adaptation. (ONR)

Cooperative ResourceManagement for IP-based Radio Access Network

Xin Wang

Next generation wireless networks will needto support applications with diverse band-width and quality of service requirements, amixture of real-time and non-real-time, cir-cuit- and packet-switched services, anddevices with different transmission capabili-ties and frequency agility. The principalresearch objective of this project is to devel-op a comprehensive resource managementframework for supporting heterogeneoustraffic seamlessly over a radio access sys-tem. Specific goals include studying the fun-damental resource-allocation problems inthe air interface (including CDMA, OFDM,802.11) and backhaul networks (with wiredlinks or WiMAX long-range wireless links andin mesh topology for scalability and reliabili-ty), understanding and incorporating themany interactions while implementing re-source management, and trading-off optimality with control and managementoverhead. The research plan consists of thefollowing three inter-related components:

1) Development of a holistic intra-cellresource management scheme thatincludes admission control at networklayer, packet scheduling at link layer, andpower and rate control at physical layer;

2) Development of cell load models for a mix-ture of circuit-switched and packet-switched traffic, and development of prac-tical inter-cell load control and mobilitymanagement mechanisms;

3) Investigation of scalable resource man-agement techniques for meshed backhaulnetworks, that particularly consider theeffects of mobility on backhaul resourcemanagement, path setup and controloverhead, and the reverse impact of back-haul resource control on the performanceof the air interface. (NSF)


Geometric Algorithmsfor Wireless SensorNetworks

Jie Gao

Embedded networked sensing devices arebecoming ubiquitous across many activitiesthat are important to our economy and life.The physical locations of the sensor nodesgreatly impact the system design in allaspects from low-level networking andorganization to high-level information pro-cessing and applications.This project takes ageometric approach to study algorithms insensor networks and investigates a numberof fundamental ideas about (a) how the geo-metric embedding of sensor networks influ-ences how the network can operate? (b) howto exploit the geometric characteristics forefficient and scalable network design? Theproject addresses a number of importantarchitectural components where geometryhas a fundamental influence, including local-ization, topology discovery, naming and rout-ing, information discovery and brokerage,and mobility, in a harsh environment in whichsensor networks operate: inaccuracy orunavailability in location information, limitedresources such as bandwidth and energy,noisy or incomplete data, preferable distrib-uted computation and high link or node fail-ure rate. Expected results include the explo-ration of new models and abstractions, andnovel geometric algorithms with provableperformance guarantee in a probabilistic,dynamics and information incomplete world.We expect that the exploration of sensor net-works' rich geometric properties will revealkey insights that enable the creation of large-scale sensor networks. In addition, this inter-disciplinary project provides a bridgebetween communities of computationalgeometry and wireless networking — iden-tifying important geometric problems for thecomputational geometry community as wellas supplying efficient algorithmic solutionsfor the networking community. (NSF)

ComputationalGeometry for NetworkOptimization

Joseph S. B. Mitchell

In this project, we bring to bear the tools ofcomputational geometry to design, analyze,implement, and test algorithms for networkoptimization and related problems that arisein several application areas, including geo-metric network optimization, sensor net-works, robotics, air traffic management, geo-metric modeling, manufacturing, computer-aided design, and geographic informationsystems. The main project goal is the devel-opment of fundamental advances in geomet-ric algorithms. Additionally, the projectstrives to foster and deepen collaborationswith researchers in application domains andindustry, in order to formulate their algorith-mic needs precisely and to make availablealgorithmic tools, insights from theoreticalresults, and software from experimentalinvestigations.

Our Computational Geometry Lab has devel-oped state-of-the-art algorithms for severalfundamental geometric problems. Manycompanies use licensed software from theComputational Geometry Lab for triangula-tion, collision detection, Voronoi diagrams,NC machining tool path planning, and pro-cessing of geometric models. In addition, wehave made several algorithms for vehiclerouting and air traffic management freelyavailable to researchers.

Our focus areas include:

a) Optimization of Geometric Networks: Weconsider optimal routing and networkdesign in geometric contexts, includingthe geometric Traveling SalesmanProblem (TSP), vehicle routing, con-strained spanning trees, minimum-weightsubdivisions, optimal route planning withconstraints, and survivable networkdesign. We have made fundamentaladvances to approximation algorithms forcomputationally hard problems, such asthe TSP and its variants that arise innumerous network applications.

b) Sensor Networks and Swarm Robotics:We develop algorithms for sensor local-ization, sensor coverage and optimaldeployment, data field monitoring, and adhoc networking for stationary or mobile(robotic) sensors. We are particularlyinterested in problems that involve net-working of mobile agents. In our work inoptimal sensor coverage we have devel-oped one of the most effective systems forplacing sensors in geometric domains.

c) Air Traffic Management: We have devel-oped mathematical models and algorith-mic solutions to several challenges thatarise in the Next Generation of AirTransportation System. The goal is theoptimal use of airspace in the face ofdynamic and uncertain constraintsinduced by weather and traffic conges-tion, sectorization (load balancing amongsectors and centers), and optimization ofthe network structure of the NationalAirspace System.

d) Shape Approximation, Virtual Models, andManufacturing: We have developed newgeometric algorithms for shape approxi-mation in geometric modeling, collisiondetection of virtual models, virtual proto-typing, and manufacturing process plan-ning (e.g., NC pocket machining, inspec-tion paths, and spray coatings).

We attack the problems on two fronts:

1) We apply formal algorithmic analysis,attempting to prove the tightest possiblebounds (upper an lower) on the worst-case or average-case time/space, orapproximation ratio for the problem; and

2) We develop solution techniques designedto be simple, fast, and practical, and weperform experimental analysis to find thebest methods in practice. (NSF)

CEWIT 9


A Miniaturized RoboticTestbed forDevelopment, Testing,and Evaluation ofProtocols on Multi-HopWireless Networks

Tzi-cker Chiueh

While most mobile wireless research pub-lished in the literature took a simulationapproach to protocol testing and evaluation,the simulation tools used in these studiesrarely went through a rigorous validationprocess. As a result, the validity of these sim-ulation results is at times called into ques-tion, especially when the protocols understudy may be substantially affected by thepropagation and interference characteristicsof physical radio channels, such as researchon cross-layer protocol optimizations. Oneway to improve the fidelity of simulationresults is to use highly accurate models forradio signal propagation and interference.Unfortunately, applying them to simulationsof wireless networks consisting of more thandozens of nodes requires a tremendousamount of computation and thus is not verypractical for large networks. Recognizing thelimitations of simulations, increasinglyresearchers choose to test and evaluatewireless protocols directly on a real testbed.Ideally, a wireless network testbed shouldconsist of a large number of potentiallymobile nodes, and allows software protocolsrunning on these nodes, the initial networktopology, node mobility patterns, and offeredinput traffic loads to be easily reconfigurable.Unfortunately, such a testbed is both expen-sive to build and difficult to manage andmaintain, because it needs to span a largegeographical area when commodity radiotechnology such as 802.11 is used. In thisproject, we will design, implement, and eval-uate a miniaturized wireless network testbedcalled Mint, which aims to approximate theideal wireless network testbed in every

aspect but significantly decreases its physi-cal space requirement.As a result, Mint dras-tically reduces the deployment, manage-ment, and configuration overhead, andmakes it practical to construct large-scalewireless network testbeds at a modest cost.Mint is designed to support both wirelessprotocol simulation and wireless systemstesting and development. To leverage thelarge number of existing ns models, Mintsupports direct execution of ns scripts over anetwork of wireless nodes, and provides thesame look-and-feel as if the ns simulationsrun on a single machine. To facilitate thetesting and debugging of wireless protocolimplementations, Mint supports a flexible APIfor accessing link-layer, network-layer andtransport-layer implementations in the test-bed, and incorporates a declarative networkfault injection and result analysis tool thatgreatly simplifies the process of injectingspecific faults and analyzing responses fromprotocol implementations being tested. (NSF)

Scalable Monitoringand Discovery ofEnterprise Networks

Tzi-cker Chiueh

A key building block of enterprise networkmanagement is the ability to provide real-time visibility of the configuration, traffic loadand traffic content of the networks undermanagement. This project aims to develop ascalable network monitoring system forwired and wireless networks deployed inlarge enterprises.

To solve the enterprise-scale managementproblems associated with modern WLANtechnology, we propose a scalable WLANtraffic monitoring system that is designed toprovide comprehensive reports on input traf-fic load and radio channel usage in real timefor all WLAN links in an enterprise, and sup-ports MAC-layer intrusion detection by iden-tifying anomalous network events such asMAC address spoofing, unusual probing andAP switching frequencies. In addition,Carlsbad is designed specifically to be astransparent to the monitored WLANs as pos-sible in two senses. First, Carlsbad does notrequire any modifications to the monitoredWLANs, nor does it require any manual con-figuration for itself. Secondly, Carlsbad doesnot disrupt the operation or affect the per-formance of the monitored WLANs.

Because intra-enterprise wired networks areless likely to be congested or compromised,this project focuses on wired network serviceand configuration discovery, more specifical-ly the following three types of information:

1) Link-layer topology: how switches,routers, hosts and servers are physicallyconnected through Layer-2 links.

2) Network-layer topology: how routers par-tition hosts and servers into distinct Layer-2 subnets.

3) Network service map: which networkservices are deployed on which servers,and

4) Service dependency map: which hostsaccess which services. (CA)

CEWIT 11

Self-powered WirelessSensor Technology forMonitoring the Healthof Electric PowerTransmission Systems

Yu Zhou, Xin Wang and Peisen Huang

This research will investigate a novel ener-gy-saving sensor architecture for the wire-less sensor network technology used inmonitoring electric power transmission sys-tems. Blackouts caused by failures in elec-tric power transmission systems directlyaffect household and commercial opera-tions. Heavy public dependence on electricpower transmission demands superiorcapabilities of monitoring and diagnosis inorder to maintain the health and extend thelife of the electric power transmission sys-tems and prevent catastrophic failures.

Manual monitoring and diagnosis is time-consuming, and inconvenient in remote andhazardous regions. Remote sensing usingthe wireless sensor network provides apractical solution to efficiently diagnoseweak and failing components in the field. Aset of wireless sensing nodes will be distrib-uted in the electric power transmission sys-tem under monitoring, with each nodeattached to a tower, connector or anothercritical point. Each wireless sensing nodeconsists of one or more sensors and a wire-less transceiver. The sensor will monitor thestatus of the associated component in theelectric power transmission system, regis-tering the parameters such as voltage, cur-rent, temperature, humidity, pressure, vibra-tion, etc. The readings will be sent out usingthe wireless transceiver towards a centralstation. The central station collects the data,diagnoses the problem and makes deci-sions on maintenance. Based on the remotesensing, corrective maintenance actionsmay be taken to prevent catastrophic fail-ures which would otherwise lead to severepower outages. (SBU, CEWIT)

Airborne Video SensorNetworks forSurveillance andEmergency Response

Himanshu Gupta, GoldieNejat, C.R. Ramakrishnan andDimitris Samaras

This project develops a technological infra-structure for deploying and using ad hoc air-borne video sensor (AVS) networks. In par-ticular, autonomous blimps are used as theairborne platform, and are equipped with acompact processing unit, sophisticatedcamera assembly, and certain sensingdevices. The AVS network can be envisionedbeing used for detection of unusual activi-ties in emergency and disaster control situ-ations, monitoring of unplanned events, etc.

One of the main research components in-volves development of efficient algorithmsfor various versions of the video coverageproblems in the context of the AVS network.The second main research component ofthe research involves declarative represen-tation and automated evaluation of high-level video activities. In addition to above,the project also entails research issues thatarise in the areas of robotics and computervision. An important component of the workis development of two testbeds - one with alarge number of autonomous indoor blimpswith a modest camera set-up, and the otherwith a smaller number of larger autonomousoutdoor blimps with a sophisticated cameraset-up.

The broader impact of this project is newapplications that the AVS network facilitates,especially those requiring response tounplanned emergencies and threats. (NSF)

Desynchronizaton inWireless Ad-hocSensor Networks

Jennifer L. Wong

Desynchronization is a biologically-inspiredprimitive to solve the round-robin schedul-ing problem in multi-agent distributed sys-tems. Applying the primitive in a wirelessad-hoc or sensor network provides a colli-sion-free self-organizing network withoutthe need for a global clock. As opposed tosynchronizing all nodes to operate duringthe same time period, with desynchroniza-tion each node is assigned an operationperiod which is distinct from its neighbors.

In this project, we aim to develop robust andefficient desynchronization protocols forresource constrained wireless ad-hoc sen-sor networks. In addition, the focus is on uti-lizing desynchronization as the foundationof higher level protocols and algorithmswithin the network. For example, desyn-chronization can be applied for coordinatedsensor sampling of nodes deployed in geo-graphically local regions. The sampling loadis distributed equally amongst the nodeswhile maintaining sensing coverage andincreasing the battery lifetime of the net-work. Additionally, nodes with identical sub-sets of communication neighborhoods candesynchronize their schedules and timeshare message forwarding/routing, allowingfor each node to power down for extendedperiods. (SBU)

12 Software Systems

Lattice Simulation andRendering

Arie Kaufman and Klaus Mueller

This project introduces an innovative latticeof the computation and rendering domain,the hexagonal lattice, for a variety of 3D and4D wave phenomena simulations, such aslighting, acoustics and tomography. Thehexagonal lattice discretizes the domain intolattice sites, where every site is connected to12 neighbors in contrast with the cubic cell inCartesian grids. Photons, phonons, wavelets,or wavefronts are traced on the lattice linksand interact at the lattice sites (e.g., scatter-ing, absorption) using cellular automata likeprocesses. The proposed work investigatesand develops structures, constructions, sam-pling, algorithms and applications of thehexagonal lattices. The hexagonal lattice canbe applied in and has the potential to revolu-tionize a variety of applications, such as sim-ulation and rendering of light, acoustics andtomography, and has the potential to a verybroad impact by extending the framework tomany other particle based wave phenomena,such as those in particle physics. (NSF)

Testing and Verificationof Concurrent Software

Scott D. Stoller

Concurrent (multi-threaded, parallel, or dis-tributed) software is becoming increasinglycommon, as a result of the growing availabil-ity of multi-core processors, multi-processorcomputers, and grid computing. Concur-rency poses significant challenges for soft-ware development. Often, bugs in concur-rent applications manifest as errors onlyunder specific scheduling and timing condi-tions. Consequently, errors are hard to repro-duce and diagnose, and bugs are found verylate in the testing process or after deploy-ment of the system to end users.

This project focuses on the development oftechniques and tools for testing, analysis,and verification of concurrent software. Wehave developed, implemented, and evaluat-ed efficient and effective algorithms to detectcommon synchronization errors (and poten-tial errors) in multi-threaded programs,including data races (unsynchronized con-flicting accesses to shared variables), dead-locks (threads stuck waiting for each other),and atomicity violations (interferencebetween concurrently executed code seg-ments). The techniques involve static analy-sis of program source code, dynamic (run-time) analysis of program behavior, and com-binations of static and dynamic analysis.(NSF, ONR)

Cryptanalysis andCryptographic Design

Rob Johnson

Many computer security applications needcryptography, but designing and using cryp-tographic tools is difficult for non-experts. Inthis project we are analyzing published sys-tems and proposing new, more secure alter-natives where appropriate. Currently, we areimplementing an attack we previously dis-covered against the High-bandwidth DigitalContent Protection (HDCP) protocol used toencrypt video data transmitted over the DVIbus used to connect video cards and DVDplayers to LCD and other digital monitors.This protocol, originally designed by Intel, iswidely implemented in current video hard-ware and fundamentally broken. When ourattack is finished, we will recover a mastersecret that will enable us to instantly decryptdata transmitted between any two HDCPdevices. In the future, we will analyze otherDRM crypto-systems, network crypto proto-cols, such as WPA or Bluetooth, and crypto-graphic file-systems. (Funded Internally)

Micropayment andDigital Cash Systems

Radu Sion

In this project we are designing protocols forefficient, correct and secure micro-paymentprotocols for networks. We are also develop-ing practical e-cash mechanisms with strongsecurity properties, including privacy andcorrectness. (Funded Internally)

Software Systems

CEWIT 13

From Rules to AnalysisAlgorithms with Timeand Space Guarantees

Annie Liu

Many computation problems, including pro-gram analysis and model checking problemsin particular, are most clearly and easilyspecified using relational rules. Yet, develop-ing and implementing efficient algorithms forthese problems is a nontrivial, recurring task.This project proposes to develop a unifiedmethod for transforming rule-based specifi-cations into efficient algorithms and charac-terize the specifications and the transforma-tions to provide time and space guaranteesfor the derived algorithms. The project focus-es on rule-based specifications for programanalysis and model checking problems anddevelop fully automatic methods for thetransformations and the time and spaceanalysis in this domain.

The development uses a general transforma-tional method that makes computation pro-ceed in an iterative and incremental fashion,analogous to integration by differentiation incalculus. The method also exploits sophisti-cated structures for storing and accessingcomplex data. The project also proposes toimplement these methods, apply them toexisting and new analysis problems, andevaluate them by comparing automaticallygenerated implementations with other algo-rithms and implementations. The researchresults will enable faster and better develop-ment and implementations of computer soft-ware for solving practical analysis problems.The transformational approach helps assurethe correctness and efficiency of the imple-mentations. (NSF)

Runtime-Monitoringand Model Checkingfor High-ConfidenceSystems Software

Erez Zadok, Radu Grosu, Annie Liu, Scott A. Smolka and Scott D. Stoller

System software provides the critical infra-structure (libraries, operating systems, embed-ded systems, and more) on which all otherapplications run. Such software, however, isoften difficult to develop and maintain. For effi-ciency reasons, system software is developedusing the C/C++ programming languages;unfortunately, these languages are prone toprogramming errors that may not be detectedfor weeks/months after deployment. The endgoal of this project is to develop tools and tech-niques that will build self-monitoring mecha-nisms into future software. Because self-mon-itoring may impose performance overheads,the degree of monitoring will be adjusted auto-matically based on the level of confidence thesystem has. This will produce systems thatmay initially run slower due to self monitoring,but whose performance will increase over timeas statistical confidence grows. In short, thisproject aims to combine the best of bothworlds by producing software that is: (a) high-ly reliable and, (b) minimally impacted per-formance-wise by the self-monitoring. As acase study, this project will examine severalcomponents of the Linux operating system, theopen-source Unix-like system, which is receiv-ing increasing attention as a potential competi-tor to Windows. Initially, the project will focuson the Linux virtual file system, which isresponsible for organizing and protecting theconfidential and proprietary information usersstore in disk files. The lessons learned and thetools developed in this project will be applica-ble to any complex software system. Societywill benefit by having tools and techniques toproduce much more reliable software than iscurrently available to end-users. (NSF)

Operating SystemSupport for Application-Level File-SystemTransactions

Erez Zadok

File systems and databases are the two mostcommon software systems that provide reg-ulated access to the data. Databases provideACID transactions, which allow arbitrarysequences of operations to be applied atom-ically; but databases use a wide variety ofincompatible APIs. File systems, on the otherhand, provide a standard POSIX API to data,but are less reliable because they do not pro-vide facilities to apply a sequence of opera-tions atomically. Unix cannot guarantee thata user-account management system canupdate atomically: hardware and softwarefailures could leave these files partiallyupdated. Worse, many security attacks havetaken advantage of this lack of atomicity towrite arbitrary data to important system files(e.g., create a password-less root account).

In this project we investigate how to get thebest of both worlds: integrate full databaseACID properties into commodity OperatingSystems, while offering user-level applica-tions a POSIX-compliant API with transactionsupport. We port the Berkeley Database(BDB) to the Linux and FreeBSD kernels; BDBis a highly portable, efficient, and versatileembeddable database. We create a newextensible Virtual File System that offers ACIDguarantees to user-level applications. Wedevelop two POSIX-compliant file systemswith ACID semantics. The first stores data inBDB databases, and as such will have theflexibility and power of BDB's advanced datastructures and indices. Our initial user-levelprototype shows promising performance.The second ACID file system will be compat-ible with Ext2, and we will analyze the trade-offs between using general-purpose data-base components vs. developing our ownfile-system components. (NSF)

14 Software Systems

News and BlogAnalysis

Steven Skiena

The Lydia text analytics system builds rela-tional models of people, places, and thingsthrough natural language processing ofnews, blog, and other web sources. The sta-tistical analysis of entity frequences and co-locations enables us to track the temporaland spatial distribution of news entities: whois being talked about, by whom, when andwhere? We encourage the reader to checkout our news (www.textmap.com) and blog(www.textblg.com) websites to see ouranalysis of text obtained from roughly 1,000daily US and international online newssources and millions of blog postings.

The Lydia news analysis project currentlyinvolves a total of four PhD and several mas-ters students. Over the past four years wehave developed 70,000 lines of softwareaddressing all phases of news gathering(web spidering and text extraction), NLP-based analysis (entity extraction, pronounresolution, sentiment analysis), databasemanagement and statistical analysis (rela-tionship identification, synonym set con-struction) and visualization (temporal, spatial,and network analysis). (NSF, Google)

InstructionalTechnologies: theFuture of Teaching and Learning

Tony Scarlatos andLori Scarlatos

The rapid pace of technological advancesthat has made computing devices ubiquitousin our society has also expanded the realm ofpossibilities for using computing to enhanceteaching and learning, in both formal andinformal settings. Intuitive physical inter-faces, such as computer vision, speechrecognition, and sensor arrays allow for moreactive and natural interaction. Meanwhile,digital media, simulations, and computer-based instruction are proving to be effectiveteaching tools in military and corporate set-tings as well as in schools.

We are currently pursuing five areas ofinquiry.

1) Teacher-directed active learning gamesallows instructors to create lesson con-tent, and review and analyze student per-formance data.

2) Interactive whiteboard manipulatives pro-vide a natural interface for active learning,collaboration, and shared reflectionamong students.

3) Massively multiplayer online role-playinggames for teaching and learning can havelearners take on the roles of scientists,engineers, or business leaders.

4) Multiplayer agent-based simulationgames leverage game theory to allowlearners to explore social and scientificissues as they interact with autonomousagents and one another.

5) Mobile learning applications take advan-tage of mobile technologies to delivereducational content and facilitate collabo-ration in both formal and informal set-tings. (NSF, Commercial License, DOE)

Content-Based AccessControl for Blogs andSocial Networks

Amanda Stent and Rob Johnson

The popularity of social networking sites,blogging, and other content-sharing sites(e.g. MySpace, Facebook, LiveJournal) hasexploded, resulting in more personal infor-mation and opinions being available withless access control than ever before.

However, the current state of access controlon content sharing sites is abysmal. Manysites provide only the most rudimentary ofaccess control mechanisms, and even thebest provide only general role classificationssuch as private, friends-only, and world-readable. In particular, in content sharingsites the objects to which access must becontrolled form an ill-defined and heteroge-neous collection; users’ identities and rolesare equally ill-defined; and users’ accesscontrol preferences are highly malleable.

The Content-Based Access Control (CBAC)project is developing new, intuitive, easy-to-use systems for bloggers and social-networkusers to control their privacy. With CBAC,users will only need to specify high-levelpolicies, such as, “Posts about ‘work’ shouldonly be visible to ‘co-workers’.” The systemwill then use Natural-Language Processingtechniques to infer which user posts arework related and apply the correct privacypolicy. By simplifying and automating priva-cy policies, users are more likely to takeadvantage of privacy tools.

In three research projects, we developingand extending techniques for automatic con-tent analysis. We are implementing a CBACsystem for creating and enforcing content-based access control policies. We develop-ing techniques for adapting these policiesautomatically based on observation of users’content, behavior and context. We are eval-uating this research in the context of PLoG, aPrivacy/Policy aware bLOGging system.(NSF)

Parallel ComputingAlgorithms forScientific Computing

Yuefan Deng

This research on parallel computing focuses onthree main aspects: design and analysis ofsupercomputer architectures; algorithms forefficient utilization of supercomputerresources; and applications of supercomputersfor protein structure and artificial heart model-ing. Represented by paper “Design and analy-sis of new interconnection networks for ultra-scalable supercomputers” submitted (2009) toParallel Computing and “Group theory insightsfor design of supercomputer network topolo-gies” submitted (2009) to Science, thisresearch focuses on designing networks forsupercomputers suitable for physical and lifesciences as well engineering applications.The simulated performance of our systems issuperior to that of the IBM BlueGene.Represented by papers “Task mapping onsupercomputers with cellular networks” inComp. Phys. Comm. 179 (2008) pp. 479-485and “Detailed analysis of communication loadbalance on BlueGene supercomputer” athttp://dx.doi.org/10.1016/j.cpc.2009.02.006our research designs algorithms for mappingapplication tasks to minimize the communica-tion and load imbalance for higher scalabilityon large computer systems with tens of thou-sands of processing cores. Represented bypapers “Simulating botulinum neurotoxin withconstant pH molecular dynamics in general-ized Born implicit solvent” in Comp. Phys.Comm. 177 (2007) pp. 210-213 and“Simulations of a specific inhibitor of thedisheveled PDZ domain” in J. Mol. Modeling 15(2009) pp. 91-96, our research applies thecomputational power of supercomputers tomodeling of large proteins in solvents with100,000 atoms for microseconds. Ultimately,all of the computer resources must be used totackle problems in science and engineeringand we focus sharply on this goal. (FundedInternally)

Cooperative Worm Defense

Rob Johnson

Worms are the number-one threat to com-puters on the Internet today and the damagethey inflict is staggering. The Slammer wormcaused an estimated $1 billion in damage,disabled many bank ATMs, and disabledSeattle’s 911 emergency service. Wormsexploit bugs in their victim’s computers’ soft-ware, so software vendors have respondedwith patches whenever they learn of a vul-nerability. Unfortunately, patches take toolong to develop and administrators and usersare hesitant or negligent about installingthem. To solve this problem, we are develop-ing a cooperative worm defense system thatwill respond to new worms in seconds.

A cooperative worm defense system willconsist of three pieces: a worm detectionsystem, an alert dissemination network, anda software response to incoming alerts. Todetect worm attacks, we are developing newprogram transformations that automaticallyrewrite C programs to catch attempted worminfections with some lower-bounded proba-bility. This work will extend previous pro-gram transformation techniques and willsolve several problems that have limitedtheir adoption, including run-time overheadand backwards compatibility. We are explor-ing several different options for the alert net-work, including a peer-to-peer network, acentral alert distribution service, and LANbroadcast-based protocols.

Modifying software on-the-fly to respond to aspreading worm is challenging – even patch-es written carefully by expert software devel-opers can have bugs and break legitimateuses of an application. To solve this problem,our response system will only be able tomake a well-defined set of changes to therunning application. This will increase relia-bility of the system and enable system-administrators to test their applicationsagainst future hypothetical patches our sys-tem might apply. (Funded Internally)

InterdependentSecurity Models forCyber Defense

Luis Ortiz

This project will create a toolkit of novelcomputational game theoretic and economicmodels, and correspondingly efficient algo-rithms, that allow political scientists and pol-icy makers to easily explore and apply gametheoretic approaches to shared risks in cyberdefense. The research builds upon game-theoretic models of Interdependent Security(IDS): the cost-effectiveness of an agent’sdecision to invest in “security” depends onthe decisions of other individuals in the pop-ulation to which the agent is exposed. Theresearch will:

1) introduce generalizations of IDS games toexplicitly handle “external” agents (e.g.,terrorists, hackers);

2) develop and explore stochastic versions ofsuch games, which will allow us to modelscenarios where the detailed dynamics ofthe interactions are essential;

3) incorporate network structure as a corecomponent of the models;

4) create novel machine learning techniquesto infer qualitative network structure andquantify model parameters from behav-ioral data collected throughout the project.

Questions that will be addressed include:how local individual decisions affect theoverall global security in cyberspace; andidentifying key coalitions whose formationwill lead to an overall improvement in security. (DoD)

CEWIT 15

16 Software Systems

An Update-Aware DiskI/O System and ItsApplications

Tzi-cker Chiueh

The simple read/write interface exposed bytraditional disk I/O systems is inadequate forlow-locality update-intensive workloadsbecause it limits the flexibility of the disk I/Osystem in scheduling access requests andresults in inefficient use of both buffer memo-ry and physical disk bandwidth. This projectproposes a novel update-aware disk accessinterface that allows applications to specifydisk update requests and to associate withsuch requests call-back functions that will beinvoked when the requested disk blocks arebrought into memory. Because call-backfunctions offer a continuation mechanism toperform application-specific update opera-tions on retrieved disk blocks, the proposeddisk I/O interface greatly improves the flexibil-ity in scheduling the disk accesses associatedwith disk update requests. It enables a noveldisk I/O subsystem architecture calledBatching Updates with Sequential Commit(BUSC), which is optimized for workloadscharacterized by high update intensity andlow access locality, and dramatically improvesthe sustained disk update throughput byeffectively aggregating disk update requestsand sequentially committing them to disk. Inaddition, through a novel low-latency disk log-ging technique, BUSC delivers the same dura-bility guarantee as synchronous disk updateswith negligible performance penalty. Todemonstrate the effectiveness and flexibilityof BUSC, we will implement multiple databaseindexes such as B+ tree, R tree, Bkd tree andpersistent hash table on top of BUSC, leverageBUSC to build a scalable data deduplicationengine for petabyte-scale data archiving sys-tems, and apply the underlying principles ofBUSC to develop a log-structured flash stor-age system. Initial performance experimentssuggest that BUSC can deliver a performanceimprovement over conventional disk systemsunder random update-intensive workloads byone to three orders of magnitude. (NSF)

SecureWORM: Strong RegulatoryCompliant Storage

Radu Sion

Digital societies increasingly mandate proce-dures for the access, processing and storageof information. In the United States alone,over 10,000 such regulations can be found infinancial, life sciences, health-care and gov-ernment sectors. A recurrent theme in theseregulations is the need for regulatory-com-pliant storage as an underpinning to ensuredata confidentiality, access integrity andauthentication; provide audit trails, guaran-teed deletion, and data migration; and deliv-er Write Once Read Many (WORM) assur-ances, essential for enforcing long-term dataretention and life-cycle policies.

Unfortunately, current compliance storageWORM mechanisms are fundamentally vul-nerable because they rely on simple enforce-ment primitives such as software and/orhardware device-hosted on/off switches, ill-suited to their target threat model.

In this project, we will build a strongly com-pliant storage system for realistic adversarialsettings, delivering guaranteed documentretention and deletion, quick lookup, andcompliant migration, together with supportfor litigation holds and several key aspects ofdata confidentiality. Recent compliance regu-lations are intended to foster and restorehumans trust in digital information recordsand, more broadly, in our businesses, hospi-tals, and educational enterprises. As increas-ing amounts of information are created andlive digitally, compliance storage will be avital tool in restoring this trust and ferretingout corruption and data abuse at all levels ofsociety. This project will greatly advance thestate of the art and create a strong founda-tion for secure regulatory compliant designs.(NSF)

Clarity and Efficiency in Design

Annie Liu and Scott D. Stoller

Abstraction for design, such as objectabstraction, supports the separation of whatoperations are provided by systems andcomponents from how the operations areimplemented, and is essential in the con-struction of complex software systems fromcomponents. Unfortunately, clear and modu-lar designs have poor performance whenexpensive query operations are performed,while efficient designs that properly maintainthe query results are much more difficult todevelop and to understand, because thedesign may blow up significantly and is nolonger clear or modular.

This project creates a general frameworkand language for expressing design knowl-edge that support both clarity and efficiency,by rigorously capturing invariants, ways toefficiently and incrementally maintain invari-ants, and the associated costs; and to devel-op a method for automatically applying thedesign knowledge. The underlying principlesof incremental computation are the counter-part of differentiation in calculus and willhelp lay a solid foundation for science ofdesign. This project also proposes to imple-ment the framework and method, apply themto important application domains, includingsecurity policy frameworks and operatingsystems, and teach them to both undergrad-uate and graduate students. (NSF)

File System Tracing,Replaying, Profiling,and Analysis on HEC Systems

Erez Zadok and Klaus Mueller

File systems are difficult to analyze, as theyare affected by OS internals, hardware used,device drivers, disk firmware, networking,and applications. Traditional profiling sys-tems have focused on CPU usage, not on I/Olatencies. Worse, existing tools for profiling,analysis, and visualization are too simplistic,cannot cope with massive and complex datastreams, and do not scale to large clusters.We have expertise in single-host file systemtracing, replaying, profiling, and benchmark-ing — as well as having developed over 20file systems; large data analysis and visuali-zation; and designing and implementingpetabyte-size storage clusters.

In this project we are developing tools andtechniques that will work on large clustersthat scale well. We are conducting largescale tracing and replaying, collecting vitalinformation useful to analyze the cluster'sperformance given a specific application. Weuse automated and user-driven feedback toraise or lower the level of tracing on individ-ual cluster nodes to

1) “zoom in” on hot-spots and

2) trade off information accuracy vs.overheads.

We use advanced data analysis techniquesto identify performance bottlenecks, and wewill visualize them for cluster users for easeof analysis. The end goal is to help identifyI/O bottlenecks in running distributed appli-cations, so as to improve their performancesignificantly — resulting in more effectiveuse of these expensive clustering resourcesby scientists worldwide. (NSF [HECURA])

Survivable Software

Radu Grosu, Scott A. Smolka, Scott D. Stoller and Erez Zadok

We are developing the tools and techniquesfor Survivable Software, a new breed of soft-ware for embedded applications. The surviv-able-software paradigm is based on two corescientific principles: Software Monitoringwith Controllable Overhead (SMCO) andHierarchical Simplified Redundancy (HSR).Given a target overhead Ot, SMCO maximizesthe confidence the user has in the monitoringwhile keeping overhead due to monitoring atlevels that never exceed Ot. SMCO usesaspect-oriented programming to specify andimplement runtime monitors. HSR is a newfault-tolerant architecture for embeddedsoftware. Applying HSR to an embeddedsystem means that, for each critical softwaremodule, there is a hierarchy of backup mod-ules ready to resume execution of a failedmodule. Backup modules are designed formaximum verifiability and survivability.Stability analysis techniques will ensure thata backup module sees a consistent systemstate when it takes over. (AFOSR)

Authenticating Reality

Rob Johnson, Michael Benderand Dimitris Samaras

Digital photography is a poor way to authenti-cate reality because digital photographs arenotoriously easy to manipulate and falsify.Doctored images of political figures, scientificand legal evidence, and news and currentevents are commonplace. This project envi-sions a near future in which users can easilyverify the authenticity of digital media. Webbrowsers will indicate whether a given photo-graph is authentic; listeners will be able to trustthat a sound-bite has not been manipulated tochange the speaker's intent. This authentica-tion technology has the potential to revolution-ize the way society values and uses photo-graphic and other digital evidence: courtroomevidence will come with a strong guarantee ofauthenticity, photos in news articles will beprovably accurate, photographs in scientificarticles will be guaranteed to be authentic. Thisproject thus serves the interests of all scientif-ic disciplines --- not just computer security ---as well as the disciplines of law, economics,and journalism.

This project is also solving several technicalchallenges. For example, traditional docu-ment authentication schemes can onlyauthenticate a bit-for-bit perfect copy of theoriginal document. For typical usage of pho-tographs, which must be cropped, scaled,brightened, etc, for presentation on the web,these schemes are impractical. We aredeveloping new authentication schemes thatallow an editor to perform these “safe” oper-ations, but no others. Other researchers haveinvestigated statistical techniques for detect-ing forged photographs by finding anomaliesand inconsistencies in the image. Our proj-ect strengthens these approaches byenabling the statistical analyses to detectinconsistencies between the image andauthenticated internal camera state, such asits auto-focus meter readings. (NSF)

CEWIT 17

18 Software Systems

Evidence-BasedUtilization Managementof NYS MedicaidProgram

Rong Zhao

This project focuses on developing an evi-dence-based decision support system to beused in monitoring and optimizing utilizationof Medicaid services and facilitating qualityassurance measures. We are working onestablishing beneficiary-specific thresholdsfor utilization of services based on individualhealth status and eliminating unnecessarybarriers to the delivery of quality healthcareto beneficiaries. We aim to develop a frame-work that will reflect both beneficiary-levelutilization history and proven diagnosis andtreatment guidelines. (NYSDOH)

Shift-Variant ImageDeblurring

Murali Subbarao

The goal of this project is to investigate anew localized and computationally efficientapproach to shift/space-variant imagerestoration. Unlike conventional approaches,the new approach models shift-variant blur-ring in a completely local form based on therecently proposed Rao Transform (RT). RTfacilitates almost exact inversion of the blur-ring process locally and permits very fine-grain parallel implementation. The newapproach naturally exploits the spatial locali-ty of blurring kernels and smoothness ofunderlying focused images. It formulates thedeblurring problem in terms of local parame-ters that are less correlated than raw imagedata. It is a fundamental advance that is gen-eral and not limited to any specific form ofthe blurring kernel such as a Gaussian. It hassignificant theoretical and computationaladvantages in comparison with conventionalapproaches such as those based on SingularValue Decomposition of blurring kernelmatrices. Theoretical and experimental stud-ies will be carried-out and real-time hard-ware implementation will be considered.Results of this research will be extended tosolving linear integral equations and time-variant signal processing. (Funded Internally)

Feather-Weight VirtualMachine

Tzi-cker Chiueh

Many fault-tolerant and intrusion-tolerantsystems require the ability to “try out” unsafeprograms in a realistic environment withoutleaving any permanent damage. Virtualmachine technology is a perfect fit to meetthis need. On one hand, a virtual machinerepresents a complete operating environ-ment in which complex applications can exe-cute successfully. On the other, virtualizationtechnology allows multiple virtual machinesto run on the same physical machine withoutinterfering with one another or with theunderlying machine. Because such trialoperations need to be invoked frequently ona routine basis, creating, committing and ter-minating a virtual machine must be fullyautomatic and extremely low-overhead. Tosatisfy this new requirement, this projectaims to develop a new virtual machine archi-tecture for the Windows environment calledfeather-weight virtual machine (FVM). FVMis more flexible and scalable, incurs lessstart-up and run-time performance over-head, and has lower implementation com-plexity than existing virtual machine tech-nologies. The key technique behind FVM isname space virtualization, which isolates vir-tual machines by renaming resources at thesystem call interface and thus guaranteeingthat the names spaces visible to different vir-tual machines be disjoint. Through a copy-on-write scheme, FVM allows multiple virtu-al machines to physically share resourcesbut logically isolate their resources fromeach other. Finally, FVM provides a compre-hensive set of operations for users to manip-ulate virtual machines as if they are files,including create, specify, save, resume, ter-minate, copy, commit, etc. (ARO)

Secure DocumentManagement

Radu Sion

The goal of this proposed work is to investi-gate regulatory compliance for documentmanagement infrastructures and explore therequirements. One specific focus will be ondesigning and prototyping secure documentprovenance mechanisms. Document prove-nance mechanisms are essential in manyexisting regulatory frameworks. For example,HIPAA mandates logging of access andchange histories for medical records, andSOX requires secure documentation andaudit trails for financial records. (Xerox, NSF)

Patient FlowManagement

Rong Zhao

The long waits and delays in hospitals aremajor challenges to the health care industry.In this project, we are collaborating with theStony Brook University Medical Center todevelop a real-time patient flow manage-ment and decision support system. This sys-tem combines advanced operations man-agement methodologies, data mining tech-niques, and scheduling algorithms. It willallow healthcare providers to analyze capac-ity, customize workflows, reduce patients’length of stay, and improve communications.(SBUMC)

Representative ImageSelection from Web-Based PhotoCollections

Tamara Berg

Over the last few years, there has been a ver-itable explosion in the amount of image andvideo data uploaded and disseminated overthe Internet through search engines, blogs,and community photo websites like Flickr,PicasaWeb, and Facebook. The web canpotentially put a fascinating universe ofimages at the users fingertips, and yet theaverage users experience of interacting withvisual data remains impoverished and frus-trating. To find images associated with agiven concept, the user typically has to entera textual query and then sift through pageafter page of thumbnails, many of which areirrelevant or low-quality, instead of beingable to instantly access a complete, accu-rate, and visually compelling summary of thesearch results.

There is currently a significant unmet needfor computer vision and information retrievaltechnologies that can automatically deter-mine which images constitute the mostcanonical or recognizable examples for agiven query concept, and compute relevantat-a-glance summaries. Because images onthe Web have been captured, selected, andannotated by people, they share a commonhidden structure informed by human notionsof semantics, saliency, aesthetics, and com-position. This project tackles the problem ofeliciting this common structure automatical-ly through analysis of web-scale image col-lections. The resulting very succinct visualsummaries are especially helpful for searchand browsing when communication band-width is limited or display devices constrainthe amount of information that can be shownat once. (Funded Internally)

CEWIT 19

20 Software Systems

Invariant Rules forSoftware Producibilityand Assurance

Annie Liu and Scott D. Stoller

This project proposes to develop a unifiedfoundational framework for rigorously cap-turing and applying software design anddevelopment knowledge to significantlyimprove software producibility and assur-ance under complex and challengingrequirements facing real-world software.The framework is based on the notion ofinvariants that are essential in all softwaresystems, because invariants underly allrequirements about dependencies, concur-rency, distribution, fault-tolerance, security,and general safety and correctness as wellas cost and efficiency conditions.

Invariant rules are used to declarativelyspecify how complex invariants are main-tained under all possible updates to systemstates. The design and development knowl-edge captured by invariant rules underliesinvariant maintenance for design and opti-mization, invariant verification for validationand assurance, invariant discovery forunderstanding and reverse engineering,invariant tracing for justification and prove-nance, and general transformations forinstrumentation, refactoring, etc.

We especially investigate the use of invariantrules for specifying critical aspects of com-plex systems including crucial dependen-cies, concurrency, distribution, trust andsecurity, and develop methods for applyinginvariant rules in design and optimization,and in verification and validation, for thesecritical aspects. We demonstrate the use ofinvariant rules and methods for applyinginvariant rules in non-trivial case studies.(ONR)

A PolymorphicEmulation Approach toSoftware Obfuscation

Tzi-cker Chiueh

Software obfuscation and reverse engineer-ing have received relatively little attention inthe academic research community and havebeen largely considered as a black art.Among the more rigorous research efforts inthis area, most of them focus on code obfus-cation techniques that can thwart static pro-gram analysis tools. The goal of this projectis to develop obfuscation techniques that candefeat dynamic program analysis tools andmanual reverse engineering. The key innova-tion in this project is a polymorphic emula-tion approach to software obfuscation inwhich for each source program to be obfus-cated, the proposed system (called Sphinx)creates a separate instruction set and gener-ates its compiler and interpreter, compilesthe program into a bytecode representationusing this compiler, and combines the inter-preter and the bytecode into the final obfus-cated binary. By introducing an additionallevel of interpretation, Sphinx never revealsthe original binary, unlike existing encryp-tion-based software obfuscation systems. Bycreating a distinct instruction set for eachprogram, Sphinx makes it difficult to reverse-engineer the interpreter and consequentlythe bytecode representation of the originalprogram. Moreover, Sphinx features a run-time code randomization technology thatcombines variable code location assignment,metamorphic code transformation and multi-thread interleaving to defeat programmaticconstruction of control flow graphs fromdynamic instruction execution traces. Finally,Sphinx supports a general implementationframework for encryption-based softwareobfuscation that we will use to empiricallyestablish a model of obfuscation strengthand performance penalty for various obfuscation mechanisms available in thisframework. (NSF)

General-PurposeComputation onGraphics ProcessingUnits


A commodity graphics processing unit (GPU)can perform general-purpose computationsand not only the specific built-in graphicsoperations. GPU is a multi-core coprocessorthat supports high data parallelism. Its per-formance has been growing at a rate ofsquared Moore's law, and its peak perform-ance exceeds that of the CPU by an order ofmagnitude. We further advocate the use of aGPU cluster for large scale problems and forhigh performance computing. We have builta large GPU cluster, called Stony Brook VisualComputing Cluster, and implemented severalapplications on it. However, programming aGPU cluster is difficult. Therefore, we havedeveloped the Zippy framework to simplifythe GPU cluster programming. Zippy is basedon global arrays and stream programmingand hides the low-level details. The GPUclusters have the potential to become thepeta-scale supercomputers of the nearfuture. We have done much groundbreakingcomputational science work on GPU and GPUclusters, such as computational fluid dynam-ics using the Lattice Botzmann Model (LBM),medical image reconstruction (RapidCT),large-scale complex volume visualization,and hashing and compression on the GPU. Aspecific example of using the GPU clusterincludes real-time plume dispersion simula-tion in complex urban environments, such asmidtown Manhattan, where nearly 1,000skyscrapers geometries serve as boundaryconditions which substantially influence theflow. Example applications using Zippyinclude LBM, volume visualization, and iso-surface extraction. (NSF, FalconStor)

Intelligent DeformableModels

Hong Qin

Deformable models and level set methods arerelated techniques that have proven to besuccessful computational tools across a vari-ety of disciplines, ranging from computervision and image processing, computergraphics, computer-aided design and geo-metric modeling, as well as in applied mathe-matics and physics. The two techniques, eacha major investigative avenue, are comple-mentary in fundamental ways. The goal of thisproject is to harness the strengths of thesetwo physics-based methods, and unify themunder a biology-based control paradigmderived from the field of artificial life. Our unification will lead to a novel breed of intelli-gent, deformable organisms capable of per-forming a wide range of challenging dataanalysis tasks.

The anticipated outcome is a new, highlyautomated methodology for analyzing large-scale datasets that are subject to uncertainty.Through an array of research activities, thisinvestigation will advance the state of the artin the aforementioned fields, all of which havevalue in information technology. Comple-mentary subgoals will be to demonstrate thatthe new modeling paradigm is not only apowerful analysis tool for visual informationprocessing, but that it can serve as a generalcomputational technology to aid in new scien-tific discovery. In particular, our novel modelscan be deployed in massive datasets to auto-matically extract geometric boundaries anddiscover unknown topology of structures ofinterest within the data. For example, vastquantities of medical images are routinelycollected for diagnostic and research purpos-es. Our project models can aid in the process-ing of large-scale datasets, enhance the effi-ciency of domain scientists as well as ordi-nary users, facilitate modeling and renderingtasks, and streamline the entire visual infor-mation processing pipeline. (NSF)

Multivariate SimplexSplines for DataModeling andVisualization

Hong Qin

This initiative will develop a novel unified com-putational framework for data representation,multi-scale material modeling, and visualiza-tion of heterogeneous datasets towards infor-mation integration. With the advent of modernscanning and data acquisition technologies,surface geometry and volumetric datasets withever-increasing complexity are routinely col-lected. Technical challenges are to developmore powerful computational tools to serve apressing need for more accurate data model-ing, more effective simulation/analysis, andvisualization. Our objectives are to representvolumetric datasets of complicated geometryand arbitrary topology, organize their multi-scale, heterogeneous material attributes, andvisualize their geometric and anisotropic mate-rial properties in a single computational frame-work. Our technical solution is founded uponthe mathematical theory of multivariate sim-plex splines, which have remained under-explored in data modeling and visualization.

The tremendous complexity and the lack ofefficient algorithm implementation have pre-vented the theory of simplex splines from theirwidespread penetration into data modeling,material representation, and visualization sys-tems. A research goal is the algorithmic devel-opment of simplex splines for data modelingand visualization. Through a suite of researchactivities, this research will advance knowl-edge in volumetric modeling and data visuali-zation, with a goal to realize the untappedpotential of simplex splines in shape comput-ing and visualization applications. Because ofmany unsurpassed advantages of simplexsplines, this investigation has a potential tobroaden the application scope of multivariatesimplex splines in other domains includingengineering, mathematics, and science. (NSF)

CEWIT 21

22 Software Systems

Shape Space andShape Matching UsingDifferential andAlgebro-geometricApproaches

David Gu

Shape recognition, space of shapes, shapematching are fundamental problems in com-puter vision field. This project aims at develop-ing theoretically sound and practically effectivemethods to tackle these problems based onmodern differential geometry and algebraicgeometry.

The scope of this project is to cover shapeanalysis, shape matching, object recognition,surface comparison, especially shape spaceand many related mid and high-level visionproblems. The research results can be directlyapplied for computer vision, medical imaging,geometric modeling, computer graphics andmany related fields.

The objective of this project is to establish ageneral theoretic framework and develop effi-cient and practical systems for general surfacematching, shape comparison, object recogni-tion, computing the coordinates of a surface inthe shape space and measuring the distancebetween two shapes in the shape space. Thetheoretic work will lead to discrete version ofcurvature flow in differential geometry, holo-morphic differentials in Riemann surface andTeichmüller space theory.

The algorithms will be implemented and deliv-ered to the research community. The approachof this work is mainly based on differential and algebro-geometry. Unlike conventionalapproaches focusing on topological or differen-tial geometric properties of shapes, this workemphasizes the conformal structure. All sur-face in real life are Riemann surfaces, andhave intrinsic conformal structures. Conformalstructure can be explicitly represented usingholomorphic differentials. This project willdevelop the algorithm for computing holomor-phic differentials and representation of confor-mal structures. Surfaces can be classified bytheir conformal structures, all conformal equiv-alence classes form a finite dimensional shape

space, the so called Teichmüller space. Thealgorithm for computing the Teichmüller coor-dinates and geodesic distance will be devel-oped. The Teichmüller map, that minimizes thedistortion between two shapes, will be con-structed explicitly. By using Teichmüller map,different shapes can be registered and com-pared directly. In each conformal equivalentclass, there is a unique Riemannian metric withconstant curvature. By using Ricci flow, suchmetric can be obtained numerically. Therefore,all 3D surfaces can be deformed to one of thethree canonical shapes, the sphere, plane andthe hyperbolic disk. Geometric processingtasks can be accomplished in these 2D canon-ical domains. This greatly simplify the compu-tational cost. All the algorithms will be developed as software packages and madepublicly available for researchers in academiaand industry. (ONR)

Conformal GeometryApplied to ShapeAnalysis and GeometricModeling

David Gu

The conformal structure is a natural structureassociated with Riemann surfaces and playsfundamental roles in geometry and physics.Conformal structure has proven useful ingraphics and vision: conformal parametriza-tions provide high quality texture mappingwithout local distortion, as well as surfacematching and morphing with applications suchas brain mapping.

The overall goal is to explore the potential of conformal geometry for computer graphicsand vision and to ultimately make the interdis-ciplinary field of computational conformalgeometry accessible and useful to society.The direct research goals are to apply confor-mal geometry to geometric modeling andshape analysis.

Conformal geometry theory is mature butabstract. We will build and disseminate a con-crete set of software tools for computing andvisualizing the conformal structure of arbitraryreal surfaces. This will make the theory acces-sible to students and its practical applicationsuseful to the broader community. ManifoldBSpline tools based on conformal geometrywill bridge the gap between traditional polygo-nal meshes in graphics and spline surfaces inCAGD. The generic geometric search enginecan be applied to a geometric database and anInternet search engine. We will complementthe software development with a systematicdevelopment of the classic material in a con-text that permits integration into the curriculumof non-math majors. Computer graphics,vision, scientific computing, medical imaging,mathematics and physics will benefit from theresearch and education of computational con-formal geometry directly. Computational con-formal geometry has already made impacts onthe graphics industry and will be more broadlyapplied in the future. (NSF)

CEWIT 23

Discrete CurvatureFlows on Graphics andVisualization

David Gu

Curvature flows based on variational principlesplay fundamental roles geometry and topology.Discrete curvature flows lay down the compu-tational foundations to tackle many importantand long lasting open problems in graphicsand visualization. Almost all computationalalgorithms in graphics and visualization arebased on geometric structures of the mani-folds, either explicitly or implicitly. Thus it isimportant to understand various geometricstructures on surfaces and design rigorouscomputational framework to approximatethem. Discrete curvature flows are the appro-priate tools to construct different geometricstructures on manifolds by finding special met-rics with prescribed curvatures. This projectwill focus on a mathematical study and appli-cations in graphics and visualizations of sever-al recently discovered discrete curvature flowson surfaces. These flows are all based on vari-ational principle and constructed from thederivative cosine law.

The research goals are to develop the theoret-ic foundations of discrete curvature flows,study metric deformations and different geo-metric structures on surfaces using curvatureflow, and apply them to geometric modeling,computer graphics and visualization, specifi-cally: Compute the metric within conformalclass with prescribed curvature. Approximate itusing discrete Ricci flow. Understand the suffi-cient and necessary conditions for the exis-tence of solutions, the convergence of curva-ture flow, and more importantly, the qualitativemeasurement of the approximation error;Compute optimal global conformal surfaceparameterizations. If the parameterizationallows singularities, what is the optimal way todesign the locations of singularities and thediscrete curvatures on them such that the con-formal parameterization is mostly uniform;Compute hyperbolic structures for high genussurfaces, classify surfaces using their hyper-bolic invariants, register surfaces using optimalmaps based on hyperbolic metrics; Developthe corresponding mathematics, based on thevariation principle and the associated flows ontriangulated surfaces, to support these compu-tational activities. (NSF)

Computing GeometricStructures of 3-Manifolds

David Gu

With the proofs of Poincaré’s conjecture andThurston’s geometrization conjecture, it hasbeen proven in theory that all 3-manifolds canbe decomposed to prime manifolds, eachprime manifold can be equipped with one ofeight canonical geometries. Geometric struc-tures of 3-manifolds play fundamental roles ingeometry and topology. This project focuses oninventing algorithms to compute geometricstructures of general 3-manifolds, the geomet-ric algorithms combine both numerical andsymbolic methods to compute the canonicalRiemannian metrics on discrete 3-manifolds,which lay down the foundations to tackle manylong lasting open problems in graphics, vision,geometric modeling and medical imaging andmany other engineering fields.

The overall research goals are to develop thetheoretic foundations and computational algo-rithms for different geometric structures ondiscrete 3-manifolds using angle structuresand volumetric functionals, and apply geomet-ric structures to graphics, vision, geometricmodeling and medical imaging, specifically:Compute constant curvature Riemannian met-rics on general discrete 3-manifolds based onangle structure and volumetric functional;Design volumetric triangulation and re-triangu-lation algorithm. In the process of optimization,some topological obstruction of the existenceof constant curvature metric maybe encoun-tered. Then retriangulation algorithm needs tobe applied; Compute mappings between dis-crete 3-manifolds, such as volumetric registra-tion and matching; Compute the geometricinvariants of 3-manifolds for shape classifica-tion; Design volumetric parameterization algo-rithms for converting tetrahedron meshes tosplines; Study the mathematics supporting thecomputational algorithms; Study the formationof the topological obstruction for the existenceof constant curvature metrics, which leads to adiscrete version of the proof of Thurston’sgeometrization conjecture and Poincaré’s conjecture. (NSF)

Communications and Devices

24 Communications and Devices

Transport of Dropletsand Bubbles inMicrofluidic Networks

Thomas Cubaud

We experimentally study multiphase flows intransparent high-pressure microfluidic sys-tems. The manipulation of fluid interfaces atthe small-scale finds use for developingoptofluidics elements, including fluid-recon-figurable lenses and waveguides, and forsequestrating components into individualdroplets and bubbles. Nanofabrication tech-niques allow for constructing complex flowgeometries that can mimic fluidic networksencountered in nature, such as in trees,blood vessels, or porous rocks. Motivated bythe development of techniques for controllingthe structural and rheological properties ofmulti-fluid dispersions, our research focus ison transport phenomena, including hydrody-namic coupling, coalescence, and emulsifi-cation processes between low- and high-vis-cosity fluids in microchannels. A wide rangeof fluids are investigated, including thoseimportant to the energy sector, such asheavy oils, ethanol, and carbon dioxide inorder to potentially discover new pathwaysfor better petroleum oils manipulations, con-tinuous bio-fuel synthesis, and sequestrationof greenhouse gases in porous networks.(Funded internally)

High-level Synthesisand Optimization ofAnalog and Mixed-signal Systems

Alex Doboli

The goal of the research is to develop effi-cient methodologies and Computer-AidedDesign tools for automated synthesis of analog and mixed-signal systems from highlevel specifications, e.g., Matlab/Simulink,SystemC and VHDL-AMS. CAD tools help inachieving short design cycles with reduceddesign effort and providing designs that arecorrect by construction. Our mixed-signalsynthesis research addresses a top-downmethodology in which electronic circuitmacromodels are automatically producedbottom-up to capture a wide range of circuitnonidealities and nonlinearities, like polesand zeros, offset, distortion, process param-eter variation, coupling, etc. The models offerinsight into circuit operation and the impactof circuit parameters on performance.

The design automation framework includesthe following activities:

1) Specification for synthesis of analog andmixed-signal systems.

2) Performance model generation for timeand frequency behavior.

3) Architecture (topology) generation techniques.

4) Parameter optimization techniques.

We study optimization algorithms for synthesis that find as many “very good”(Pareto) design points as possible withoutrequiring feasible designs as starting points.Many other synthesis tools have difficultiesin locating diverse constraint-satisfyingdesigns. The researched methods perform acontinuous refinement process, in whichpoor quality solution space regions are elim-inated through different strategies, such asInterval Analysis, exploration of convex, qua-siconvex and ‰-convex regions, rifts andplateau, and adaptive sampling. The synthe-sis methods have been validated using filtersand ¢™ modulators. (Funded Internally)

CEWIT 25

Automated Design ofReconfigurable(Programmable)Sensing Frontends

Alex Doboli

This project addresses both theoretical andapplied research with the goal of establishingspecific and detailed guidelines for developingreconfigurable mixed-signal architectures forsensing frontends. A goal is the identification ofthe architectural features that must be incor-porated into programmable mixed-signal SoCsfor broadening applicability, improving flexibili-ty, performance, and cost.

System frontends and interfaces are importantas new sensor-based applications emerge incritical areas, like homeland security, defense,infrastructure management, energy, etc. Theseapplications require real-time data acquisitionfrom a large number of geographically distrib-uted sensors. With present interfaces andinterfacing techniques, data acquisition andcommunication is about 1000x slower anduses more energy than data processing.Moreover, it is expected that the performancelimitations of data acquisition and communica-tion will continue to intensify for many “data-hungry” applications. Intuitive solutions, suchas employing a very large number of interfac-ing devices, are limited due to the small num-ber of interfacing resources available in anSoC, e.g., I/O pins, I/O buffers, and other hard-ware. A novel way of tackling this limitationinvolves sharing the interfacing hardware formultiple data acquisition channels, such asusing reconfigurable front-ends. The reconfig-urable front-ends must be capable of process-ing and digitizing analog signals with a widebandwidth range, at varying resolutions, andwith adaptive power consumption. Reconfig-urable front-ends with programmable parame-ters and topology have the potential to achievethe above goal, as each reconfigurable modecan be customized to work for narrow resolu-tion and bandwidth ranges. (Funded Internally)

Miniature AcousticSource LocalizationSensor Node

Milutin Stanacevic

Recent advances in semiconductor fabrica-tion combined with advances in design ofmicro-electro-mechanical systems (MEMS)lead to significant miniaturization of sensordevices. Inspired by these advances, noveldesigns of integrated sensory microsystemshave a significant and pervasive potential toimpact a large number of applications.Miniaturization of sensors poses new chal-lenges in sensor integration and unfolds newopportunities to advance the sensitivity andextend the knowledge about observed environment. This calls for efforts both onalgorithmic, theoretical levels with newclasses of algorithms for extraction of essential features specific to task, and onsystem implementation level with tighterconstraints, most notably in size and power.Our research focuses on blind source local-ization and separation algorithms usingminiature sensor arrays in case of travelingwaves and their efficient implementation inmixed-signal VLSI for integrative sensorinterfaces. (National Grid)

Smart RadiationDetection Readout IC

Milutin Stanacevic

Significant efforts have been made recentlyto enhance the effectiveness of nuclear andradiological detection capabilities, specifical-ly in design of portable systems that wouldbe able to localize the threat. A proposedthree-dimensional (3D) integration of scintil-lation-type semiconductor detector pixelsprovides accurate spectroscopic resolutionfor isotope discrimination and an accuratedetermination of the direction to source atthe same time. We are investigating thedesign of integrated readout circuitry formeasurement of the optical response of pix-elated detector. Large parasitic capacitanceimposes stringent constraint in the design ofthe sensing circuitry and requires develop-ment of novel circuit techniques to relax theeffect of input parasitic capacitance.(Department of Homeland Security)


Mobile Data Gatheringin Wireless SensorNetworks

Yuanyuan Yang

This project will develop a novel integratedmechanism that utilizes a non-conventionalenergy model and the latest physical layertechnique for mobile data gathering in wire-less sensor networks. In particular, this proj-ect focuses on the following issues:

1) develop the tour planning algorithms forthe mobile actuator based on sensor dis-tribution. The issue of load balancingamong sensors needs to be investigatedalong with the moving path planning toprolong network lifetime.

2) utilize the special discharge and recoverybehaviors of sensor batteries to improvethe energy efficiency of data gatheringschemes.

3) propose cross-layer design with the latestphysical layer technique that has not beenapplied to the wireless sensor networksbefore, such as Multiple Packet Trans-mission (MPT), in order to improve datathroughput, reduce energy consumptionof sensors, and shorten the data gatheringlatency.

Wireless sensor networks (WSNs) haveemerged as a prominent data collection par-adigm for extracting local measures of inter-ests from a physical environment. Since sen-sors are battery powered and left unattend-ed after being deployed, energy consumptionbecomes the paramount concern to WSNs.Our research focuses on the energy-efficientdata gathering mechanisms with mobileactuators. We are designing novel tour plan-ning algorithms for the actuator with single-hop data gathering or multi-hop relays forlocal data aggregation while load balancingis incorporated to achieve the uniformity ofenergy consumption among the sensors. Weare also considering mounting multipleantennas on the actuator while keeping sen-sors simple. With the support of MPT, it ispossible for multiple sensors to simultane-ously upload data packets to the actuator

such that system throughput and energy effi-ciency can be greatly improved and the datagathering latency is effectively shortened.Moreover, we also use a discrete time modelto characterize the discharging and recoverybehaviors of sensor batteries. Based on thismodel, we propose the route scheduling a-mong sensors for local data aggregation withthe awareness of battery status, which uti-lizes the fact that a fatigue sensor battery willbe somewhat “recovered” after idling. Ourresults demonstrate that such a scheme cangreatly save energy at sensors. The algo-rithms we propose are to be further validat-ed on a wireless testbed being developed inour lab, which makes them more practicalfor real world applications. (NSF)

Ultra Low LatencyOptical PacketInterconnects

Yuanyuan Yang

With the advances of modern computerarchitectures, interconnects are playing anever increasingly important role in communi-cations of computer systems today, rangingfrom communications among multicores,chip-to-chip, different boards, multi-proces-sors, local area networks and wide area net-works. Over the next decade, the bandwidthof interconnects inside a computer is expect-ed to increase beyond multiple Gbits/sec tomatch the processing speed. This increasewill require a shift in technologies from elec-tronic to optical domain. Advanced opticalswitching technologies, such as opticalpacket switching, are required for ultra-highspeed communications. The recent introduc-tion and rapid growth of the wavelength-

division-multiplexing (WDM) technology pro-vides a platform to exploit the huge capacityof optical fiber. Optical interconnects thatcombine the advantages of WDM with pack-et switching capability are strong candidatesfor future ultra-low latency, ultra-high speedinterconnects with throughput in the hun-dreds of terabits/sec range. In recent yearsoptical interconnects with WDM have attract-ed considerable amount of attentions, bothfrom industry and academia. However, mostworks either use optical-electrical-optical(OEO) conversion to store the data in elec-tronic form, which requires a large number ofexpensive fast optical transmitters andreceivers, or assume the use of immature alloptical technologies, such as full rangewavelength converter. This project provides anew switching paradigm-optical cut-throughwith electronic packet buffering, and sys-tematically investigates the fundamental andchallenging issues in the optical interconnectunder this switching scheme with the objec-tive of designing cost-effective ultra-lowlatency and pragmatic interconnects forfuture high-performance computing andcommunications systems.

This project combines optical packet switch-ing with electronic buffering, such that theinterconnect will enjoy both fast switchingand large buffering capacity. The projectexplores a spectrum of issues in designingthe optical interconnect under the newswitching scheme. Specially, it focuses on:

1) designing the switching fabric and packetscheduling algorithms, such that the inter-connect maintains work-conservative-ness and packet order at high speed withlow latency;

2) designing practical Forward Error Control(FEC) code to ensure high-reliability;

3) conducting extensive performance evalu-ations by means of simulations and emu-lations tools and analytical models. (NSF)

CEWIT 27

Passivation of GaSb-surface byMicromachining andFormation of a Native Oxide

Muralidhar Kumar, DmitriDonetski, and Jon Longtin

There is an insatiable demand for higherwireless communication speeds. Free SpaceCommunication (FSC) systems operating atterahertz (THz) frequencies are becomingincreasingly attractive for commercial satel-lite networks and military applications.Compared to radio-frequency (RF)-basedsystems operating the mega- and gigahertzrange, terahertz frequencies for satellite andintersatellite communication offer higherdata rates, smaller and lighter equipment,lower power consumption, and the availabil-ity of new frequency ranges. In addition, sys-tems operating above 3 THz do not need tocomply with current radio regulations.

Heterodyne methods are widely employed incommunication systems, however GaAs-based Schottky diodes typically used for THzdetection and frequency mixing have funda-mental limitations in the high-frequency per-formance. These limitations originate fromthe parasitic resistance associated with thefinite carrier mobility and the skin effect. Toovercome these effects, expensive in imple-mentation approaches have been proposed,such as using superconductive hot-electronbolometers. The proposed approach over-comes parasitic and skin-effect limitations ofclassical Schottky diodes by using both high-mobility materials and wafer bonding fol-lowed by ultrafast laser micromachining.

Semiconductor devices based on GaSb, InAs,InSb and their alloys are being developed fora long time due unique electronic propertiesof these materials. High electron mobility,broad spectra of the available bandgaps andenergy offsets of these materials are criticalfor both microwave and optoelectronic appli-cations. Achievement of the competitive fre-quency response with scaling down dimen-sions of the GaSb-based devices is desired.At the present time it is rather limited by sur-face effects which require innovativeapproaches to address the problem. Highdensity of defect states at the surface, bandbending leading to an accumulation layerlead to elevated surface current. Passivationof the surface then becomes essential toimprove the surface properties of GaSb.Surface passivation using sulfur-based solu-tions forming thermally stable S–III and S–Vbonds is widely employed. Though suitablepassivation schemes using sulfur basedspecies have been demonstrated (a 3.6times reduction of the dark current as report-ed in literature), the passivated surfacedegrades with time after exposure to theatmosphere.

The project is focused on achieving passiva-tion by alternative methods – by microma-chining and by pulsed anodization. Standardmicroelectronic fabrication methods such asReactive-Ion Etching (RIE) are found to causedamage to the device surface. Micro-machining by removal of materials withultrafast (femto-second scale) laser pulses isknown to be free from thermal effects andassociated damage. Mesas of Schottky inter-faces were fabricated by micromachiningand their surface currents were compared tountreated Schottky diodes obtained fromconventional processing techniques. It wasfound that micromachining does not damagethe surface as opposed to RIE and that itreduces the surface current in devices whencompared to unpassivated devices obtainedby lithography. Alternatively, the pulsedanodization of the surface of Schottky barri-ers was utilized for protection of the surfacewith a thick layer of oxide. With the lattermethod a 10.7 times reduction of surfacecurrent without encapsulating the mesasidewalls has been demonstrated. (FundedInternally)


A System Infrastructurefor Scalable and RobustWireless Communicationsand Services

Xin Wang

There are increasing demand and scope fordeploying wireless networks with meshedtopology. However, developing a comprehen-sive, working service framework over ameshed wireless network involves a numberof challenges, due to channel dynamics,node mobility, and the limited capabilities ofmany wireless devices. The objective of ourproject is to develop a distributed and geo-metric network and service managementinfrastructure for scalable and robust wire-less communications and services. A loca-tion information architecture will be integrat-ed into the system, and used by the routingand service management functions. The sys-tem will also include several stateless virtualinfrastructures to significantly increase therobustness of communications and reducemanagement complexity. The proposed sys-tem consists of five key components:

1) A resource monitoring framework willenable scalable and reliable tracking oflocations, resources and service avail-ability, and liveness of wireless nodes ina dynamic environment;

2) Service and resource discovery schemeswill allow the registration of distributedresources, the publication of services,the searching of resources from a largepool of providers, and the identification ofa group of providers to support servicesrequested by a client;

3) Efficient and robust service and data deliv-ery will be supported with robust and light-weight one-to-one and one-to-many geo-metric unicast and multicast schemesdesigned specifically to deal with mobilityand channel dynamics, and deal with avariety of traffic patterns required in aservice oriented environment;

4) A fast and robust backbone network willbe constructed to enable timely androbust delivery of delay-sensitive dataover a long range;

5) Service management and maintenancemechanisms will assume various strate-gies to facilitate uninterrupted services.(Funded Internally)

SuperconductorElectronics Based on RSFQ

Mikhail Dorojevets

The critical need for high-performance inDoD computer systems is well recognized.Extremely high processing speeds poten-tially reaching 100 GHz coupled with very low power consumption (an order of 10 nW/gate/GHz, which potentially can beimproved towards a limit of ~ 0.5nW/gate/GHz) make superconductor elec-tronics a very promising candidate for use infuture high-end computer systems. While thecurrent approaches allowed designers toreach frequencies of up to 20 GHz for low-complexity bit-serial processor pipelines,they are not scalable or applicable to future50-100 GHz 64-bit RSFQ processor design.The objectives of the first phase of the proj-ect (2008-2009) are (1) to develop asynchro-nous hybrid wave pipelining techniques, and(2) specify, design at the gate level, andquantitatively evaluate several key blocks fora 50 GHz 64-bit RSFQ processor. (ARO)

Forward-ScatteredSignal-Based Systemfor Detection of UHECR

Mónica F. Bugallo and Petar M. Djuric

The research from this project adds to theefforts of scientists throughout the world tocollect information about Ultra High EnergyCosmic Rays (UHECR), that is, the rate oftheir occurrence and the location where theyare detected. The purpose of the work is toexploit the potential of forward-scatteringtechniques for detecting and analyzing sig-nals that are set off by UHECR. These meth-ods are based on similar principles as thoseof radar and allow for building inexpensivestations that can achieve the pursued objec-tive and can easily cover very large geo-graphical areas. The research activitiesrevolve around three themes: (a) develop-ment of an improved forward-scattered sig-nal model using as starting point the existingtheory, (b) design and building of hardwarearchitecture for signal acquisition based onfeasibility computations, and (c) processingof the forward-scattered signals, whichincludes detection, estimation, classification,and localization. The purpose of the project,too, is to demonstrate the viability of themain ideas by proof-of-principle tests first inlaboratory and then out in the field. (NSF)

A Flexible NetworkInfrastructure forVersatile WirelessCommunications

Xin Wang

Several fundamental technical issues arethreatening to limit the enormous potential ofwireless communications. One major issue isthe mushrooming of devices and PHY andMAC protocols that are mutually incompati-ble, and the inflexibility of these protocolswhich makes them unable to utilize the avail-able spectrum efficiently and to adapt toapplication and task requirements. Other keyproblems include the interference and spec-trum-fracturing caused by the uncoordinatedcooperation of different devices and stan-dards, and the lack of network system infra-structure to harness the available spectrumfor increasing the performance of wirelessnetworks. Our objective is to develop andimplement an agile wireless network infra-structure to support versatile communica-tions using the same network protocol stack,to flexibly allocate bandwidth based ondevice capabilities and user applicationrequirements, and to coordinate and enablemore powerful and robust wireless commu-nications over heterogeneous nodes with dif-ferent and varying local spectrum usages.The proposed Agile Spectrum Management(ASM) infrastructure will enable wirelessdevices to self organize and build a flexiblenetwork topology using currently unoccupiedparts of the spectrum, communicate withdiverse devices, adapt to spectrum usage,interference, channel conditions, jammingattacks, application requirements, and peercapabilities, and coexist with and minimizeimpact towards other systems. The infra-structure will use Software-defined radios(SDR) as a common platform in order to facil-itate adaptability. Broadly, the main functionsto be developed are the efficient detectionand accumulation of the available spectrum,flexible allocation of the pooled spectrum

among different devices, coordination ofspectrum usage and detection, the buildingof network topology over nodes with differentlocal spectrum usage maps, and the adapta-tion of transmission parameters, communi-cation paths, and channel allocation inresponse to various factors. System develop-ment will span physical, link and networklayers, and will involve significant interac-tions and coordination between functions atindividual layers. (Funded Internally)

Multi-View StereoCamera System for 3D Imaging

Murali Subbarao

Three-dimensional (3D) imaging is anemerging application area with a vast marketpotential. The goal of this research is todevelop, implement, and test, innovative andadvanced 3D imaging algorithms and tech-niques. The three main topics to beaddressed are:

1) accurate and fast stereo matching andpolygon generation,

2) multi-view stereo camera calibration andregistration, and

3) seamless merging of multi view partial3D models (merging of both 3D shapeand texture maps).

Camera systems for face recognition, auto-mobile safety, surveillance, and 3D mobileimaging will be considered. (Olympus)

Development of a NewRFID System

Petar M. Djuric and Akshay Athalye

Radio Frequency Identification (RFID) is atechnology for remote identification ofobjects. Its range of applications is wide andincludes supply chain management, indoorasset tracking, healthcare, manufacturingand robotics. Today's passive and semi-pas-sive RFID systems are incapable of deter-mining the precise location of tagged objectsand estimating the direction of movement ofobjects that are tagged. Another major short-coming of today's commercial passive RFIDsystems is the low percentage of successfultag reads, which are typically in the rangefrom 60% to 85%. Low read rates haveproved to be a severe limiting factor in thewidespread adoption of passive RFID. Wework on the development of an RFID systemthat will resolve these problems. Our systemhas a third component that can detect anddecode the backscatter from tags in its nearvicinity and in turn can communicate withthe reader using backscatter modulation.When added to standard RFID systems, thiscomponent will enhance their capabilities inallowing for precise location of passive andsemi-passive tags and for solving someimportant related problems such as deter-mining direction of tag motion, demarcationof physical read zones and prevention of cross reads between adjacent read zones. They will also help in increasing theread rates of passive RFID systems. (Fundedinternally)

CEWIT 29


Digital ImagingTechnology for NewGeneration Cameras

Murali Subbarao

The goal of this research is to develop inno-vative and advanced technologies for appli-cation in a new generation of digital camerasin three main areas:

1) high-performance autofocusing (AF),

2) object-tracking AF, and

3) image restoration/reconstruction.

A major theme of this research will be to shiftthe increasingly larger portion of the imagingwork from hardware elements to softwaremodules. For example, the AF unit in an SLRcamera may be replaced by a Depth-from-Defocus (DFD) AF module implemented insoftware. The requirement of an expensivehigh precision optical system to obtain high-fidelity images may be replaced by a low-cost optical system and a “soft-focusing”module which computes high-fidelity imagesusing the shift-variant Point Spread Function(PSF) of the low-cost optical system. As thecost of computation and memory decrease,exploiting software modules to reduce thecost of hardware elements will becomeincreasingly attractive. (Olympus)

The Stony BrookTrusted Hardware Lab

Radu Sion

The Stony Brook THL constitutes a centralacademic expertise and research knowledgerepository on secure hardware, a nation-wide first of its kind. It will support commu-nity-wide educational and research activi-ties, and provide direct hands-on or net-worked access to remote or visiting researchcommunity members. (NSF, IBM)

A Market-DrivenApproach to DynamicSpectrum Sharing

Samir R. Das and Himanshu Gupta

To counter the inefficiencies of the currentspectrum usage, regulatory bodies, all overthe world, are exploring ways to deregulatethe spectrum market by allowing flexibledynamic spectrum access (DSA) in a broadrange of spatio-temporal scale. Recentadvances in radio technology have given animpetus to this trend. For DSA to fulfill itspromise of economic and societal impact,wireless services based on DSA must becommercially successful, and a tangiblespectrum market must evolve that can besupported by technology. This research proj-ect is building a realistic DSA architecture forcellular networks supported by appropriatemarket mechanisms in an integrated fashionthat is both technically and economicallyviable and efficient. This is a truly transdisci-plinary approach spanning the fields of wire-less networking and systems, algorithmics,economics, simulation and modeling, whichleads to a deeper understanding of thedynamics of the spectrum market by (a) real-istic modeling of various market entities (i.e.,buyers, sellers, and the market mecha-nisms), (b) dynamic spectrum demands andbids based on innovative and realistic popu-lation dynamics models, and (c) new androbust market clearing mechanisms withprovable performance guarantees. Theresults will be validated using large-scalesimulations, and experiments on a prototypetest bed with reconfigurable radio hardware.In addition, this project offers insights intomarket driven spectrum sharing, providesuseful tools for policymakers, and will ulti-mately guide spectrum policy decisions inDSA technology. This project is in collabora-tion with Virginia Tech and Alcatel-LucentBell Labs. (NSF)

Enabling InteroperablePublic Safety RadioCommunications

Xin Wang

Failure of public safety communication sys-tems may endanger lives and property. Thereare two main factors that limit the reliabilityand availability of these systems. First, differ-ent agencies may use systems that areincompatible, because they use different fre-quencies, or different modulation or encod-ing systems. Second, the radio spectrumdedicated to public safety use is limited andfragmented. In this work, we consider thesupport of inter-operability between differentpublic safety systems at network level andthrough IP-based technology. Besides allow-ing for the interoperability of different fre-quency bands, the use of IP as a commoninterface enables multiple agencies to sharetheir networks independent of the accesstechnologies. It also allows the system toevolve to support new radio bands and newIP-based technologies, while supporting theexisting systems simultaneously. We willconsider the exploitation of multicast to sup-port group communications, and incorporateefficient quality of service mechanisms toensure the availability of emergency commu-nications. It is anticipated that this work willlead to a deeper understanding of the specialissues involved in deploying systems forpublic safety operations, and will result in thedevelopment of resource management toolsthat will accelerate the deployment. (DOJ)

Energy Efficiency inWireless SensorNetworks

Yuanyuan Yang

The objective of this project is to develop abattery-aware cross-layer mechanism withdynamic power management that provides acomprehensive solution to achieve highenergy efficiency in sensor networks.Specially, this research focuses on the fol-lowing tasks:

1) to develop battery-aware routing proto-cols to maximize the battery lifetime ofsensor nodes by fully considering both themathematical battery models and the col-laborative nature of sensor nodes;

2) to investigate the cross-layer sensor net-work architecture with energy efficientcomponents by taking into considerationsof battery awareness in wireless sensornetworks;

3) to design battery-aware backbone routingalgorithms for sensor networks in adynamic power management approach toreduce packet redundancy and minimizepower consumption of packet routing inthe network.

A sensor network is a distributed self-config-uring multi-hop wireless network, which iscomposed of a large number of self-organ-ized, unattended nodes. Sensor nodes, whichare small in size and communicate un-teth-ered in short distance, consist of sensing,data processing and communication compo-nents with limited battery supply.

With the increasing power demands frompower-intensive and long-lifetime sensornetwork applications, the limited batterysupply on sensor nodes becomes a criticalbottleneck for sensor networks. Our researchfocuses on the unique battery discharging-recovery characteristics and designs energyefficient battery aware models for wirelesssensor networks: when discharging, batter-ies tend to consume more power than need-ed, while such over consumed power can bereimbursed when they stops discharging andbegin to rest. We propose a discrete timemodel with an on-line battery capacity com-putation functions, based on which we pres-ent a battery-aware routing (BAR) protocol todynamically schedule routing in sensor net-works. BAR is aware of the battery status ofnetwork nodes and schedules recovery toextend their lifetime. We also introduce a bat-tery aware connected dominating set(BACDS) architecture to efficiently schedul-ing the packet routing in wireless sensor networks. Our results have demonstratedthat our battery aware protocols can greatlyenhance the performance of wireless sensornetworks. The algorithms we propose are tobe further validated on a wireless testbedbeing developed in our lab, which makesthem more practical for real world applica-tions. (NSF, ARO)

ReconfigurableArchitecture for DSPApplications

Sangjin Hong

In this project, we are interested in exploringthe potential benefits of a data-driven recon-figurable computing approach where the in-trinsic computational characteristics of com-plex operations are exploited. Our approachis further motivated by the lack of a datacentric computational model to facilitate sys-tematic high-level (coarse-grain) transfor-mations of many computationally intensiveoperations into hardware. To this end, werecently introduced distributed flexible con-troller, which allows us to map complex non-linear signal processing algorithms to hard-ware by configuring a small set of parame-ters. The potential benefits of the proposalcan be quite huge, and hence we are cur-rently exploring these benefits further in thisproject. We anticipate this research to lead toa new architecture design paradigm-one thatrelies on buffer centric architectures, ratherthan conventional ALUs and data-paths.Therefore, we expect to make a significantimpact on the way that next generationprocessors are designed and built. Ourapproach will also focus on the architecturedesign and both FPGA and single chip real-izations of data centric reconfigurable archi-tectures to make sure that the potentialadvantages and disadvantages of this newprocessor architecture model are not over-looked and are fully explored. (NSF)

CEWIT 31

32 Systems and Infrastructure

Intelligent MobileTechnologies for Social Impact

Jennifer L. Wong, andAnita Wasilewska

There are over 3.5 billion mobile phones inthe world and they are proliferating atastounding rates across socio-economic andcultural boundaries and provide unprece-dented opportunities for enabling socialimpact and technical activism. The focus ofthis project is the development of practicalapplications and technology furthering socialimpact around the world. We envision mak-ing social impact on individuals and commu-nities across a variety of areas such as eco-nomic and social development, education,advocacy, human rights and healthcare.(Funded internally)

Combining Informationfrom Words andPictures

Tamara Berg

Words and pictures are often naturally linked.This can be seen in the availability of manyvast collections containing images with asso-ciated text. Sources for these include: collec-tions of museum material; digital library col-lections; any video with sound or closed cap-tioning; images collected from the web withtheir enclosing web pages; or captioned newsimages. The amount of multi-modal dataaccessible on the web is enormous and liter-ally growing exponentially. For example, onesource for consumer photographs is Flickr, anon-line photo sharing site where users canupload photos, and share them with theirfriends, family, or with the world. Flickr cur-rently has over 3 billion photographs and isexpanding by several million new uploads perday. Around half of these photos have beenassociated by the user with some form of textstring (tags, descriptions comments, etc).Withthe growing popularity of sites like Flickr,Google Video, and YouTube, the amount ofvisual data, and also of visual data associatedwith some sort of text will only increase incoming years.

In order to provide users with effective ac-cess to these collections there are severalbroad tasks that we are focused on improv-ing in this project: organizing the collectionsautomatically or with a small amount of userinput, being able to search the collectionswith high accuracy, and developing methodsfor browsing the collections in natural ways.So far we have demonstrated promisingresults on combining text and image infor-mation to automatically label faces in newsphotographs with associated captions, andclassify images depicting animals from theweb. Making this process as efficient as pos-sible in terms of communication, computa-tion, and user interaction is especially impor-tant in the setting of mobile devices. (FundedInternally)

On New StochasticApproaches for Solving Forward andBackward Problems ofBiochemical Networks

Petar M. Djuric and Mónica F. Bugallo

Advances in the development of models thatcan satisfactorily describe biochemical net-works are extremely valuable for under-standing life processes. These networks arerepresented by chemical species and sets ofchemical reactions. Signal processing canplay a very important role in the studies ofbiological systems via the stochasticprocesses that describe them. There are twomain problems in such studies. The first oneis referred to as the forward problem andaccounts for simulation of the dynamics andbehavior over time of the system. The secondproblem is called the inverse problem andamounts to estimation of unknowns (sizes ofspecies and reaction rates), or selection ofthe most adequate model that represents thesystem. The work in this project is focusedon the development of signal processingmethods for addressing both problems. Forthe forward problem, a new scalablemethodology that does not require use ofMonte Carlo simulations is studied. For theinverse problem the objectives include (a)development of methods for estimatingunknowns, (b) derivation of the posteriorCramér-Rao bounds of the obtained esti-mates, and (c) development of methods formodel selection. Validation of the proposedmethods is carried out numerically on syn-thetic data in terms of accuracy, stability andscalability, and on real data obtained fromexperiments on various signal pathways.(Funded Internally)

Systems and Infrastructure

Theory of GeneralizedParticle Filtering

Petar M. Djuric andMónica F. Bugallo

The known particle filtering methods requirea mathematical representation of the systemdynamics and assumptions about

1) the state transition probability distributionfunction, and

2) the likelihood of the states.

All the information regarding filtering, predic-tion, and smoothing of the unknowns is con-tained in the appropriate filtering, predictiveand smoothing probability distribution func-tions. These functions are approximated bydiscrete measures composed of particles(samples) from the space of unknowns andweights of the particles. By clever use ofBayes’ theorem and the concept of impor-tance sampling, the discrete measures areupdated with the arrivals of new observa-tions. This involves generation of a new sup-port of the measures and computation of theweights of the particles. The probabilisticassumptions used in standard particle filter-ing methods are often inaccurate and madeout of convenience. In many cases, the inac-curacies lead to formidable degradations inperformance of the particle filters. In thiswork our main goal is to develop a more gen-eral class of particle filters which do not useprobabilistic model assumptions. Instead, thenew filters are based on discrete measuresdefined by particle streams and associatedcosts that are also sequentially updated. Withthe newly developed theory, one is able tobuild particle filters that are simpler, moreaccurate, more robust, and more flexiblethan the conventional ones. The standardparticle filters, however, are particularinstances of the new filters. We investigate ingreat detail various important issues includ-ing the foundations of the new filters, theirconvergence, connections of the new theorywith existing theories, and extensions tobatch type signal processing. (NSF)

Multi-robot Explorationand Deployment

Yu Zhou

The objective of this research is to investi-gate a set of novel techniques for multi-robotexploration and deployment in various envi-ronments, in order to establish a technicalfoundation for efficient multi-robot coopera-tion. Multi-robot systems have potentialadvantages over individual robots in per-formance, robustness and versatility. Thecapability for multiple mobile robots with lim-ited sensing and communication to rapidlyand accurately explore and deploy in variousenvironments is of fundamental importanceto various applications, such as surveillance,environment monitoring, disaster rescue,space exploration, de-mining, etc. Specificresearch tasks include studying distributedcoordination schemes for efficient multi-robot exploration and communication, devel-oping distributed multi-robot deploymentalgorithms to optimize the sensory coveragewhile maintaining communication connec-tions, and investigating distributed sensor-based motion planning schemes to onlineupdate robot paths and avoid collisions. Ifsuccessful, this research will provide a set ofbasis techniques to enable robust and scala-ble multi-robot exploration and coverage.(Funded Internally)

Target Tracking

Petar M. Djuric and Mónica F. Bugallo

The essential objectives of target trackingare the estimation of the target location andthe kinematic parameters of the target. Amore challenging problem is tracking of mul-tiple targets. There, the measurements arisefrom the targets when they are detected andfrom clutter. In this problem, not only thestates of the targets have to be estimated butalso the possibly time-varying number of tar-gets. Besides an increased complexity due tothe larger number of targets being tracked atthe same time, a qualitative difference is theassociation of the various measurementswith the tracked targets. Another type ofproblems involves the tracking of maneuver-ing targets. In the past, most of the efforts ontarget tracking have been focused on targetsthat do not change their regimes of move-ment while they are tracked. If the targetshave several regimes of movement, i.e., dif-ferent movement models, they can maneu-ver, which implies that tracking cannot besuccessful if it is done with one model. Wealso investigate tracking problems withknown constraints. For instance, the con-straints can relate to the speed range of thetracked object or some other limitations in itsdynamics. Such prior information whenexploited properly improves the performanceof the proposed filters. (ONR)

CEWIT 33

High-performance RuleEngine for IntelligentWeb InformationSystems

Michael Kifer

Rule languages have been a popular choicefor research on intelligent information sys-tems for over three decades now. However,until recently, the lack of necessary comput-ing power and of suitable networking infra-structure prevented wide adoption of thisparadigm in software development. With theadvent of the Semantic Web and followingwide recognition of the limitations of its cur-rent standards, such as RDF and OWL, rule-based systems were put firmly back on theagenda. As proof of this renewed interest, ahost of projects are expected to release newrule-based engines in the near future, andthe World Wide Web Consortium is busy stan-dardizing the necessary infrastructure, theRule Interchange Format.

Most of the aforesaid projects, however, aimat a low-hanging fruit by augmenting exist-ing Semantic Web languages with simplerule-based capabilities. Their aim is to pro-vide for the most basic today's needs of thedevelopers of semantic content on the Web.In contrast, our project targets future intelli-gent information systems, which require veryexpressive and high-performance rule-basedknowledge programming languages. In thiswork, we develop new and integrate existingtechnologies ranging from higher-order,frame-based, and defeasible knowledge rep-resentation, to reasoning about processes, totruth maintenance, databases, and logic pro-gramming. (NSF, Vulcan, Inc.)

A Framework forAnalyzing and EnsuringTrust in Service-Oriented Architectures

Scott D. Stoller, R. Sekar, andC. R. Ramakrishnan

A fundamental aspect of our approach is theuse of provenance and obligations in speci-fying and managing trust relationshipsbetween services. The project will develop aflexible language for expressing service-ori-ented security policies, and develop a frame-work for gathering, passing, and verifyingsecurity-related information. Dynamic infor-mation flow tracking will be used to deter-mine how a service uses and transforms itsinputs. This will enable correct propagationof trust information (provenance, obligations,and perhaps security levels) from a service'sinputs to its outputs. The project will devel-op analyses to validate security policies bothwithin and across administrative domains.The analysis results will also be used to con-figure "trust firewalls": security barriers thatprevent or limit possible contamination of aservice by other services. The project willalso develop techniques to ensure thatenforcement of each part of a system'ssecurity policy depends on only an appropri-ate trusted computing base, despite dynam-ic interactions between services in multipleadministrative domains.

Our framework will allow services to interactacross a variety of common interfaces, inaddition to standardized (e.g., XML-based)service interfaces.Thus, the results will applyto many legacy systems, as well as explicitlyservice-oriented systems, such as Web serv-ices. (ONR)

Model-Driven Visual Analytics

Klaus Mueller andI.V. Ramakrishan

Modern day enterprises, be they commerce,government, science, engineering or med-ical, have to cope with voluminous amountsof data. Effective decision making based onlarge, dynamic datasets with many parame-ters requires a conceptual high-level under-standing of the data, an arguably difficultproblem. To make progress on this problemone must draw on the complementarystrengths of computing machinery andhuman insight. Recognizing this promisinghuman-computer synergy, Visual Analytics(VA), has become a major developmentthrust. VA is defined as the science of analyt-ical reasoning facilitated by interactive visualinterfaces. It seeks to engage the fast visualcircuitry of the human brain to quickly findrelations in complex data, trigger creativethoughts, and use these elements to steerthe underlying computational analysis pro-cesses towards the extraction of new infor-mation for further insight. VA has widespreadapplications, such as homeland security, thefinancial industry and internet securityamong others. We are developing a novelintelligent Visual Analytics infrastructure,rooted on techniques in machine learningand logic-based deductive reasoning. Aunique aspect of our approach is that the LPrules are automatically learned, usingInductive Logic Programming, from exam-ples of data that the analyst deems interest-ing when viewing the data in the high dimen-sional visualization interface. Using this sys-tem, analysts are able to construct models ofarbitrary relationships in the data, explore thedata for scenarios that fit the model, refinethe model if necessary, and query the modelto automatically analyze incoming (future)data exhibiting the encoded relationships.(PNNL)


Plume ModelingSimulation andVisualization


We have adopted a numerical method fromcomputational fluid dynamics, the LatticeBoltzmann Method (LBM), for real-time sim-ulation and visualization of flow and amor-phous phenomena. Unlike other approach-es, LBM discretizes the micro-physics oflocal interactions and can handle very com-plex boundary conditions, such as deepurban canyons, curved walls, indoors, anddynamic boundaries of moving objects. Dueto its discrete nature, LBM lends itself tomulti-resolution approaches, and its compu-tational pattern is easily parallelizable. Wehave accelerated LBM on commodity graph-ics processing units (GPUs), achieving real-time or even accelerated real-time on a sin-gle GPU or on a GPU cluster. Another keyinnovation of LBM is its extension to supportinput from pervasive sensors, influencing thesimulation so as to maintain its faithfulnessto real-time live sensor readings. We haveimplemented a 3D urban navigation systemand have tested it with a 10-block GIS in theWest Village of New York City, and with an851-building area in Times Square of NYC. Inaddition to a pivotal application in simulationof airborne contaminants in urban environ-ments, our approach will enable the develop-ment of other superior prediction simulationcapabilities for physically accurate environ-mental modeling and disaster management,visual simulations for computer graphics,and has the potential to revolutionize the wayscientists and engineers conduct their simu-lations. (NSF, DHS, NASA)

Visual Simulation ofThermal Fluid Dynamicsin a Water Reactor

Arie Kaufman

We develop a simulation and visualizationsystem for the critical application of analyz-ing the thermal fluid dynamics inside a pres-surized water reactor of a nuclear powerplant when cold water is injected into thereactor vessel for a possible thermal shock tothe vessel. We employ a hybrid thermal lat-tice Boltzmann method (HTLBM), which hasthe advantages of ease of parallelization andease of handling complex simulation bound-aries. For efficient computation and storageof the irregular-shaped simulation domain,we classify the domain into nonempty andempty cells and apply a novel packing tech-nique to organize the nonempty cells.We fur-ther implement this method on a GPU(graphics processing unit) cluster for accel-eration. It demonstrates the formation ofcold-water plumes in the reactor vessel. Wealso develop a set of interactive visualizationtools, such as side-view slices, 3D volumerendering, thermal layers rendering, andpanorama rendering, which are provided tocollectively visualize the structure anddynamics of the temperature field in the ves-sel. To the best of our knowledge, this is thefirst system that combines 3D simulation andvisualization for analyzing thermal shock riskin a pressurized water reactor. (NRC, ISL)

cDB: Strong RegulatoryCompliant Databases

Radu Sion

Spurred by financial scandals and privacyconcerns, governments worldwide havemoved to ensure confidence in digitalrecords by regulating their retention anddeletion. The goal of this project is to devel-op and explore a DBMS architecture thatsupports a spectrum of approaches to regu-latory compliance, thereby extending thelevel of protection afforded by conventionalfile-based compliance storage servers to thevast amounts of structured data residing indatabases. The key challenge of this work isto provide compliance assurances for theDBMS, even against insiders with super-userpowers, while balancing the need for trust-worthiness against the conflicting require-ments for scalable performance guaranteesand low cost. The resulting architecture pro-vides tunable tradeoffs between security andperformance, through a spectrum of tech-niques ranging from tamper detection totamper prevention for data, indexes, logs,and metadata; tunable vulnerability win-dows; tunable granularities of protection;careful use of magnetic disk as a cache andof secure coprocessors on the DBMS plat-form and compliance storage server plat-form; and judicious retargeting of an on-diskencryption unit. This work enables compli-ance laws to be applied to business, govern-ment, and personal data now stored in data-bases, increasing societal confidence in suchdata. (NSF)

CEWIT 35

NS3: NetworkedSecure SearchableStorage with Privacyand Correctness

Radu Sion and Erez Zadok

Today’s computing and storage servicesmandate security and correctness assur-ances to detect and deter malicious attacksor faulty behavior. This is particularly relevantfor network storage services such as net-worked file systems. In this project we willbuild robust, efficient, and scalable content-search mechanisms for networked data stor-age using three strong security assurances:

1) data confidentiality,

2) search pattern privacy, and

3) correct data retrieval.

Today’s networked storage services are fun-damentally insecure and vulnerable to faultybehavior by even weak attackers, becausethey do not handle all three dimensions con-sistently. The lack of access pattern privacyusually allows for statistical attacks compro-mising data confidentiality. Even if privacyand confidentiality assurances are in place,to be practical, networked storage shouldallow remote searching within the out-sourced data without compromising its con-fidentiality. Moreover, if the remote store can-not be fully trusted, search query complete-ness and data retrieval integrity (i.e., correct-ness) become essential. Therefore, solutionswhich address these dimensions separatelyare incomplete and insecure. We will handlethem jointly.

The total cost of ownership of storage is 5-10 times greater than the hardware costs,and more information is produced and livesdigitally every day. In the coming years,secure, robust and efficient storage manage-ment will be demanded by users. This proj-ect will greatly advance this field, creating aframework for remote-storage businesses toflourish, and for users in all fields flocking touse these new services. (NSF)

Deductive Frameworkfor ProgrammingSensor Networks

Himanshu Gupta, Samir Dasand David Warren

Programming a sensor network is hard; itforces the programmer to work in low-levellanguages that expose details of the hard-ware, low-level optimization decisions, andbuild network machinery. A programmingmethodology is needed that will allow a userto specify the overall functionality of theapplication at a high-level using a suitableprogramming framework.

Ideally, the specified user program would beautomatically translated to optimized distrib-uted code that runs on individual nodes. Thisproject attempts to realize the above visionby viewing the sensor network as a distrib-uted database of facts gathered from theenvironment. The belief is that the collabora-tive behavior of a sensor network applicationcan be easily abstracted in terms of deduc-tive rules that manipulate the facts, while thenon-collaborative behavior can be embed-ded in built-in functions.

The main goal of the project is to develop aquery engine for efficient in-network evalua-tion of deductive queries in sensor networks.The query processing plan includes transla-tion of the user program into optimized virtu-al memory code, which is downloaded intothe sensor nodes for distributed execution.The research results would be prototyped innetworking simulators (TOSSIM and ns2) andin real sensor network platforms based onBerkeley motes and Gumstix-like boards.

The above research plan has the potential ofgreatly simplifying the design and use ofsensor networks, by bundling all the low-level complexities of design choices andoptimizations in the query engine. Examplesof domains that will benefit from our contri-butions include ground traffic, emergencyresponse and disaster relief operations,physical phenomenon such as weather andstorm tracking, forest fire tracking, migrationpatterns of animals/birds, etc. (NSF)


The Impact of StorageSoftware and Aging onPower Consumption

Erez Zadok

Power management is becoming a dominat-ing concern in computing systems. Today,storage systems consume substantialamounts of power, which require additionalpower to support cooling needs. We investi-gate the impact that different storage soft-ware has on power consumption, usingtraces, and collect as much accurate data aspossible. Such a study would be very usefulfor storage hardware vendors and storagesoftware developers, who could developtechnologies to improve power consumptionof future storage systems.

The File systems and Storage Laboratory(FSL) at Stony Brook's computer sciencedepartment has extensive experience in storage research. In particular, we haveexperience in file system and storage bench-marking, file system tracing, and file systemtrace replaying.

We will replay traces over different hardwareand software configurations, and experimentwith various aging strategies for disk drives.We will measure overall, as well as instanta-neous power consumption of the system. Wewill aim to answer the following questions,among others: what is the impact of disktypes and sizes on power consumption? Howdoes the file system age affect power use?What file systems are tend to consume moreor less power, and under which access pat-terns? Is there a way to tune or reformat afile system to consume less power? Arethere any kernel or disk configurationparameters that can conserve power beyondtypical APM/ACPI systems? How do extra vir-tualization layers affect power consumption(LVM, RAID, virtual machines, etc.)? Givenenough time, we may also investigate thesame on other operating systems, such asAIX, Windows, BSD, Solaris, etc. (IBM)

Consensus Protocols:Analysis, Simulations,and Implementation

Wendy Tang and Eric Noel

Consensus protocols have a long history indistributed computing. In a distributed sys-tem such as sensor networks, “consensus”means to reach an agreement regarding acertain quantity of interests that depends onthe state of every node in the network.A “consensus” protocol is an interaction rule that specifies the information exchangebetween a node and its neighboring nodes.The speed of reaching a consensus is amajor performance metric for consensusprotocol. Network design problems forachieving fast convergence in consensusprotocol has been an important researchproblem.

In this project, we focus on the design of thenetwork topology to achieve a high algebraicconnectivity which is a measure of the speedof convergence. In existing literature, a ran-dom-wiring scheme has been used to rewireexisting links yielding faster convergence. Inthis project, we explore the effect of pseudo-random rewiring based on Cayley graphs.We plan to explore the trade-off betweencomputational cost and convergence rate.Both simulations and testbed implementa-tions are being explored. (SPIR/OmnitekPartners LLC)

Wireless UtilityMonitoring and Controland for Efficient EnergyUtilization

Jon Longtin, Jacob Sharony,Satya Sharma and Samir Das

Most utility meters (gas, electric, water) inNew York State are operated off-line andrequire human intervention for meter read-ing, resulting in meter usage data that isavailable only once every 1-3 months. Thisresearch project focuses on developingstate-of-the-art wireless meter reading tech-nologies that can be retrofitted onto existingutility meters. The technology uses industry-standard hardware and protocols for thewireless data exchange, which leveragescost and avoids a single-source supplier.Meters can be read multiple times daily withthe results sent over the internet to utilitycompanies. Usage information can also besent into the house to the homeowner, pro-viding an indication of the direct cost andusage of energy in real time. Additionally,techniques for high-resolution metering arebeing developed that can be used to trackthe energy consumption and efficiency ofmajor home appliances. The technology canalso readily be extended to control and limitenergy usage to further save energy.(NYSERDA)

CEWIT 37

Declarative Frameworkfor Learning andEvaluating ProbabilisticModels of Events inSensor Networks

Himanshu Gupta, Samir Das,C.R. Ramakrishnan, I.V. Ramakrishnan andDavid Warren

Programming a sensor network is difficult,since the programmer has to juggle low-leveldetails of distributed computing with severeresource constraints, in the presence of noisydata and unreliable components. This projectfocuses on high-level specification of eventsand activities in sensor networks, since sen-sor networks are typically deployed for col-laborative detection of events and activities.In particular, the project uses a declarativeprogramming framework based on proba-bilistic logic for high-level specification ofevents in sensor networks. The probabilitydistributions embedded in the user programare automatically learned from training examples using standard machine learningtechniques. The above approach facilitateshigh-level specification of sensor networkapplications, which is automatically translat-ed into low-level distributed code running onindividual sensor nodes. The user is thusfreed from the burden of worrying about low-level details.

The project focuses on the following threegoals. The first goal is development of aquery engine for efficient distributed evalua-tion of probabilistic deductive queries in sen-sor networks. The second goal is to developtechniques for efficient estimation (and dis-tributed re-estimation) of probability distribu-tions embedded in the given program. Thethird goal is to test the viability of the devel-oped techniques by building two appropriatetest beds. The research project has a signifi-cant impact on the ease of programming var-ious sensor network applications. (NSF)

Geometric Algorithmsfor Air TrafficManagement

Joseph S. B. Mitchell

The air transportation problem is fundamental-ly geometric: numerous vehicles must safelymove through a shared geometric domain,while staying at safe distances from each otherand from constraints, such as weather haz-ards, special use airspace, etc. As the demandincreases for air transportation, it becomesvital to use the limited airspace in the safest,most efficient manner. This is where methodsof computational geometry and optimizationcome into play.

In a project titled “Resource Management toAddress Weather Impacts in Super-DenseTerminal Airspaces”, we develop mathematicalmodels and algorithms for increasing through-put in the air transportation system. The projectexamines the super-dense terminal airspaceproblem, in which aircraft are merging, climb-ing, descending, and making approaches toairports within a complex airspace in the vicin-ity of one or more major airports. We developcapacity estimation methods, routing algo-rithms, and weather forecast analysis tools forunderstanding the complex interactions amongair traffic and weather systems, particularly inlight of the uncertainty of weather predictionmodels. We have built the “Flow-Based RoutePlanner” (FBRP) to search for multiple well-separated paths through a region of airspace inthe presence of an arbitrary set of time-varyingconstraints. The system views flights as four-dimensional trajectories in space-time.Weather hazards are specified by forecasts, atdifferent times in the future, each with somemodel of uncertainty. We study the challengingproblem of routing air traffic among stochasti-cally specified systems of weather, ultimatelyhoping also to account for uncertainty inweather forecasting, while always respectingthe need for the highest possible degree ofsafety. In a related project titled “Translation ofWeather Information to Traffic FlowManagement Impact”, we use tools of computational geometry to model and solve

algorithmic problems in analyzing impacts ofdifferent types of weather phenomena (turbu-lence, icing, convection) on different classes ofaircraft and on the throughput capacity of air-spaces in the National Airspace System (NAS).The project involves the design and analysis ofnew multi-class routing algorithms for use insimulation experiments on real data scenariosin the NAS.

We also study optimization problems related tothe effective control and oversight of airspace.In the project “Capacity-Enhancing Conceptsand Algorithms for Dynamic Organization ofAirspace”, we develop methods for optimizingnew airspace organization concepts that willassist increasing the capacity of the NAS.

The National Airspace System (NAS) isdesigned to accommodate a large number offlights over North America. For purposes ofworkload limitations for air traffic controllers,the airspace is partitioned into approximately600 sectors; each sector is observed by one ormore controllers. In order to satisfy workloadlimitations for controllers, it is important thatsectors be designed carefully according to thetraffic patterns of flights, so that no sectorbecomes overloaded. We formulate and studythe airspace sectorization problem from analgorithmic point of view, modeling the prob-lem of on problem with constraints. The nov-elty of the problem is that it partitions dataconsisting of trajectories of moving points,rather than static point set partitioning that iscommonly studied.

We are developing a suite of algorithms in asystem (“GeoSect”) that applies the tools ofcomputational geometry and optimization todevise algorithms for optimal workload balanc-ing. We have applied our methods to air trafficdata supplied by Metron Aviation and NASA.Our methods show promise of improving theefficiency and minimizing congestion-relateddelays in the air transportation system.(Metron Aviation, NASA Ames)


A Multi-Semantic, Goal-Oriented ProgrammingParadigm forDependable Operationof Massively DistributedReconfigurable Systems

Alex Doboli

Our primary goal is to develop programmingmodels, languages, and the supporting compil-ing and optimization methods for implement-ing dependable massively distributed reconfig-urable systems that operate in dynamic condi-tions. The research has two major objectives:

1) To create novel programming models forscalable and reliable description of mas-sively parallel Cyber Physical Systems con-sisting of reconfigurable, embedded nodeswith analog, digital, and software parts.

2) To develop decentralized resource manage-ment methods including low-overhead co-design for dynamically reconfiguring theanalog-digital-software components ofembedded nodes.

While massively distributed computing sys-tems have the potential to produce significantleaps in healthcare, energy conservation,homeland security, environmental protection,etc., there are currently no scalable methodsfor systemic co-design of large, heterogeneoussystems. Tackling dynamic performancerequirements through system reconfigurationis an additional challenge.

The research pursues two concepts: goal-ori-ented programming models and languages formassively parallel systems, and devising multi-domain resource management methods fordependable operation in dynamic conditions.Goal-oriented models are implicit descriptionsof concurrency, while the compiling/optimiza-tion support infers the optimal level of paral-lelism for a set of requirements. For predictableresource management, we research a decen-tralized, self-regulating transformation mecha-nism that integrates multiple semantic models,like Finite State Machines, Conditional TaskGraphs, and Markov Decision Processes.(Funded Internally)

Sensors and SensorNetworks Applicationson Complex Systemusing Intelligent FaultDetection andDiagnosis (iFDD)

Imin Kao

Sensors and sensor networks provide abun-dant information for both real-time systemmonitoring and analysis, especially in largecomplex systems. With the help of wirelessmesh sensor networks, the physical designof the system becomes more flexible and themaintenance of the system more efficient.Our research on fault detection and diagno-sis (FDD) of a complex mechanical pneumat-ic system utilizes various sensors and net-work of sensors, both wired and wireless,and employs signal processing techniquesfor diagnosis. The research encompassesnetwork sensing and information processing.Early detection and diagnosis of faults inmanufacturing and/or mechatronic systemare important for preventing failure of equip-ment and loss of productivity, the techniqueof intelligent fault detection and diagnosis(iFDD) can be employed to capture systembehavior and to diagnose impending faults.The project focuses on establishing the fin-gerprint from one element to the whole sys-tem and on correlating the relationshipbetween various sensory information.

The expected results of application of iFDD insuch systems include critical leakage infor-mation of both specific location and estimat-ed quantity of faults. In addition, the multi-quadrant vectorized map can predict possi-ble faults precisely with the redundant infor-mation provided by the sensor network. Weexpect that the future exploration of sensornetworks will provide us with an efficientpath to identify possible faults with deeperinsights into systems, based on coupled sen-sory information consisting of different partswith distinctive features. (NSF)

Scheduling for Paralleland DistributedSystems

Thomas Robertazzi

At Stony Brook, a unique mathematicalmethodology has been developed for sched-uling in parallel and distributed systemsinvolving what are called “divisible” loads.Divisible load can be thought of as large lin-ear data files that need to be processed orsearched for patterns. For instance one maywant to average billions of numerical entriesor search billions of entries for particular pat-terns/waveforms. The data may be arbitrar-ily partitioned and portions sent to differentprocessors to gain the benefits of parallelprocessing. The methodology developed todate allows a tractable calculation of howmuch load to send to each processor for thefastest possible solution, taking into accountnetwork topology, networking and processorspeeds and data characteristics. The theoryalso allows a performance comparison ofscheduling policies and network architec-tures. Work begun at Stony Brook on theseanalytical models has been undertaken byresearchers throughout the world. (NSF,ONR, BNL)

CEWIT 39

High-Dimensional DataVisualization MadeAccessible UsingIllustrative Techniques

Klaus Mueller and Kevin McDonnell

In this project we seek to exploit illustrativetechniques to make complex high-dimen-sional relationships more apparent. A stan-dard method for the visualization of multidi-mensional data is the classical method ofParallel Coordinates (PC). In PC each dimen-sion is drawn as a vertical line, and eachmultidimensional point is visualized as apoly-line that crosses each axis at the appro-priate position to reflect the N-D position. ThePC methodology facilitates the 2D renderingof very complex datasets in a single image.However, PC suffers from a few shortcom-ings. For example, PC plots tend to be verycluttered, with polylines crossing and over-lapping each other. To overcome this prob-lem, we use clustering to group nearby N-Dpoints into a single representative N-D point,and then draw these points as heavy poly-lines on top of the PC plot, using colors toshow their memberships in the mutually dis-joint clusters. Multi-resolution techniquescan impose a hierarchical structure on thedata, and dimension reordering can restruc-ture the datasets in an automatic or semiau-tomatic manner to minimize clutter.Focus+context approaches can also reduceclutter, enabling the analyst to glean insightsinto extremely dense datasets.

Unfortunately, despite all of these efforts, PCplots often still do not clearly convey the dis-tribution of the data on each axis. That is,with so many overlapping lines it can be dif-ficult to discern how dense or sparse thedata points are on each dimension. Our proj-ect offers a new suite of techniques whichwe call Illustrative Parallel Coordinates (IPC).The overarching philosophy behind IPC is togenerate PC-style visualizations that conveya large amount of information about thedataset in a relatively small area of thescreen. Our major goal is to produce abstractrenderings of complex, multi-dimensionaldatasets that reveal large-scale structures.Further, it is also desirable to create aesthet-ically pleasing visualizations that draw theeye to important features of the data, such asthe distribution of values and the density ofthe points. We achieve these goals by devis-ing new illustrative rendering techniques andby improving upon existing PC visualizationmethodologies. (Funded Internally)

On Networks andBehavior: AComputational GameTheoretic Approach tothe Study of Influence

Luis Ortiz

This project explores a computational game-theoretic approach to the study of influencein very large, network-structured popula-tions. It will study a variety of fundamentalcomputational problems within a simplemodel of behavior and influence. In particu-lar, the work seeks to:

1) delineate the limits of computationaltractability;

2) generate network-aware efficient algo-rithms and practical heuristics with prov-able quality guarantees;

3) provide tools to perform policy analysis bydesigning algorithms for identifying keyinfluential individuals within a network;

4) create novel machine learning technologyfor inferring the model parameters andnetwork structure directly from publiclyavailable behavioral data.

The research seeks to significantly improveour ability to apply game-theoretic models inpractice. It will extend our current computa-tional understanding of simple models ofbehavior by considering more complex non-monotonic, asymmetric influences of variedstrength among a very large population ofhighly heterogeneous individuals. The projectwill add to the current effort in computer sci-ence to tackle difficult problems within thesocial sciences.

The computational technology generated bythe research will lay the foundation for thedevelopment of sophisticated software andother computational tools. This technologymay radically change the way social scien-tists and policy makers analyze behavioraldata, and develop informed policies to leadcomplex systems of interactions to desirablestates. (Funded internally)


Development of LaserScanning OpticalImaging System forNoninvasive and in vivoTrans-cutaneousImaging at SubcelularResolutions

Yin Pan and Shmuel Einav

Biological systems are highly complex. Inmany applications, multi-facet imaging of abiological system can provide physiologicaland functional information that an individualimaging is unable to provide. For instance,fluorescence [Ca2+] imaging is intracellularCa2+ imaging and due to dye labeling limita-tions, current fluorescence [K+] imaging isstill limited to extracellular K+ imaging.Because of difficulties in multiple labeling(e.g., of cell membrane, nuclei,... ) in vivo, wehave been working on complimentary non-fluorescence labeling cellular imaging tech-niques. Ultrahigh-resolution OCT is one of themost promising techniques. Our recent tech-nological advances (e.g., time-lapse uOCTtermed as TLuOCT) have allowed us to imagenuclei of low-scattering epithelium. To inves-tigate the potential of TLuOCT for noninva-sive transcutaneous imaging, we recentlyperformed rodent animal study. Despite thefact that skin is one of the most challengingtissues for optical imaging due to its over-whelming light scattering, our results clearlydemonstrate the technical capability toimage nuclei of dermal cells appearing asdark holes. The nuclear size measured byOCT (9-12µm) is slightly bigger than that ofhistology (6-10µm); otherwise, they correlatewell to each other. While incorporating withneedle-based NCME imaging, we anticipatethat TLuOCT could provide complimentarycellular confirmation and confirm the depthat which [K+] & [Ca2+] sensing is performed.(HSC, CEWIT)

Potassium Monitoring

Perena Gouma, Yin Pan andShmuel Einav

As our understanding of the benefits ofPotassium (K+) grows, intolerance for low orlow-normal K+ levels and greater acceptanceof high to high-normal levels emerges.Serum K+ is generally considered to be amore reflective measure of long-term dietaryK+ intake. Serum K+ should be monitored, asa matter of course, in all patients who arenewly diagnosed with hypertension, heartfailure, or any other illness requiring therapywith a diuretic or agent that inhibits the Renin-Angiotensin-Aldosterone System(RAAS), such as blockers, angiotensin-con-verting enzyme inhibitors, angiotensin-receptor blockers, vasopeptidase inhibitors,or a range of K+-sparing agents. In fact, theserum Na+/K+ ratio is more closely correlatedwith blood pressure. Patients at risk for thedevelopment of hyperkalemia, such as thosewith some degree of renal impairment or dia-betes, those taking K+-sparing medications,or those taking exogenous K+ supplements,should have K+ values monitored more regu-larly at the discretion of the treating physi-cian. Factors that cause transcellular K+

shifts will complicate interpretation of theserum K+ value.

Progress in remote health care depends onthe development of practical monitors.Recent advances in biosensors, computingand wireless technologies can provideunprecedented diagnostic capabilities andlowered costs. One important public healthproblem that can benefit from such cost-effective, state-of-the-art monitoring is K+

monitoring. Transcutaneous measurement ofPotassium and Calcium is an unmet yet chal-lenge to the Biomedical EngineeringCommunity.

Both optical and nano-composite methodshave been attempted with no success, so far.Exposing the skin to the electrodes for longerperiods of time caused skin irritation andinjury. The electrodes had difficulties dealingwith movement artifacts and coherencedetection. As a result, transcutaneous meas-urement remained an important target.Whether monitoring high blood pressurepatients population (close to 60 millions inthe USA alone) or dialysis patients population(half a million in the USA), K+ monitoring car-ries important prognostic implications be-cause it is a risk factor. We have alreadydeveloped biological, optical and piezoelec-tric sensors and the necessary algorithms forthe automatic detection of other symptoms,such as Asthma or Atrial Fibrillation. Thesesensors were developed with sensitivity of98.44% and specificity of 97.65%. Thesesystems have the advantage of being robust,compact and reusable. We envision a smalldevice packaged with a wireless transmitterand microprocessor with embedded detec-tion software, which takes the diagnosis ofK+ from the exclusive domain of the hospitaland physician’s office to the patient’s home.This device should be inexpensive and easyto operate, yet equipped with sophisticatedcommunication capability. These character-istics will allow it to be widely deployed andto screen populations at risk. The wirelesstransmitter in the monitor can relay theresults over either the internet or via cellphone to the company for post processing.Since the analysis is performed on thedevice, no bandwidth is consumed by trans-mission of raw data. (HSC, CEWIT)

CEWIT 41

Medical

Computer AidedDetection of ColonCancer

Arie Kaufman

This project involves a method for computeraided detection (CAD) of colorectal cancer.The CAD pipeline automatically detectspolyps while reducing the number of falsepositives (FPs). It integrates volume render-ing techniques and conformal (i.e., anglepreserving) colon flattening with texture andshape analysis. Using our colon flatteningmethod, the CAD problem is greatly simpli-fied by converting it from 3D into 2D. Thecolon is first digitally cleansed, segmented,and extracted from the CT dataset of theabdomen. The colon surface is then mappedto a 2D rectangle using conformal mapping.This flattened image is colored using a directvolume rendering of the 3D colon datasetwith a translucent transfer function.Suspicious polyps are detected by applying aclustering method on the 2D flattened imageto locate regions with irregularity and high density.

The FPs are reduced by analyzing shape andtexture features of the suspicious areasdetected by the clustering step. Comparedwith shape-based methods, ours is muchfaster and much more efficient as it avoidscomputing curvature and other shapeparameters for the whole colon wall. Wetested our method with 88 datasets from NIHand Stony Brook University Hospital andfound it to be 100% sensitive to adenoma-tous polyps with a low rate of FPs. The CADresults are seamlessly integrated into a virtu-al colonoscopy system, providing the physi-cian with visual cues and likelihood indica-tors of areas likely to contain polyps. This,serving as a second reader, allows the physi-cian to quickly inspect the suspicious areasand exploit the flattened colon view for easynavigation and bookmark placement. (NIH)

Computer-AidedDiagnosis System forFast, Accurate andRemote Evaluation ofAcute Chest Pain

Arie Kaufman, Satya Sharma,Jacob Sharony, Rong Zhaoand Michael Poon

Every year more than 6 million people visithospital emergency rooms (ER) with chestpain problems. The current standard of careusing serial blood tests and stress test istime-consuming, costly, and inaccurate.Published evidence is accumulating rapidlyin support of using 64 or more slice MDCT inERs or urgent care centers to rule out thepresence of significant coronary artery dis-ease especially in patients with low to inter-mediate probability of having coronary arterydisease. We are developing a computer-aided diagnosis system which will allowradiologists to remotely access and analyzecardiac CT scan imaging data. This systemwill solve the problem of transferring largevolume of imaging data over the Internet andwill also provide remote monitoring of thescanning process to ensure quality. (NIH)

42 Medical

CEWIT 43

Integrated Modelingand Learning ofMultimodality DataAcross Subjects forBrain Disorder Study

David Gu

The overall aim of this project is to develop anovel, rigorous framework for integratedmodeling and analysis of multimodality neu-roimaging data based on Riemannian geom-etry, multivariate simplex splines, and statis-tical learning. The volumetric mapping withRicci flow allows unique and reproducibletransformation of each subject’s brain fromthe high-resolution MRI data to a canonicalspherical domain where a novel high-dimen-sional multivariate simplex spline volume isreconstructed for heterogeneous data repre-sentation and indexing. The multivariate sim-plex spline together with the volumetricparameter-domain registration facilitatesaccurate volume registration of brain dataacross subjects in both parametric and phys-ical spaces. The framework provides a basisfor multimodality information integration andstatistical learning across populations.

All of our research activities will address thefollowing major themes and objectives:

1) To explore new theoretic tools based onRiemannian geometry of 3-manifolds forthe development of a novel CanonicalVolumetric Model (CVM) which providesvolumetric mapping of individual brain toa solid unit sphere with accurate match-ing across subjects;

2) To design hierarchical spherical trivariatesimplex splines for compact representa-tion, integration, indexing and visualiza-tion of multimodality heterogeneousimaging data with high efficiency andaccuracy, which can further refine theintersubject registration through level-of-detail matching in a higher dimensionalphysical space based on the integration ofthe hierarchical spline volume withLagrangian dynamics;

3) To design new statistical learning and min-ing methods to analyze simultaneouslythe variety of data across the broad rangeof spatial and temporal scales and humansubjects in order to infer the dynamics ofbrain functions in neurological diseasestudies.

The study being proposed is innovative incomputer and information science as newtheoretical results and algorithms of threedimensional Riemannian manifold, dynamicspherical trivariate simplex splines and sta-tistical learning will be invented. We expectthat the research deliverables will aid ingaining new insights in brain disorder studiesand be generalized in other data-intensivefields of science. (NSF)

Computer Games and Virtual RealityEnvironment forRehabilitation

Rong Zhao

Using computer games to augment tradition-al rehabilitation offers the potential for signif-icant therapeutic benefit. We are currentlydeveloping innovative computer games andvirtual reality environments in strength train-ing, balance training and fall prevention, andgait training. We plan to integrate these tech-nologies into rehabilitation processes todeliver high quality care to both aging popu-lation and injured veterans returning from thetwo wars. (Biodex Medical Systems)

Model-Based Learning,Analysis and Control ofExcitable Tissue

Emilia Entcheva, Radu Grosu,I.V. Ramakrishnan and Scott A. Smolka

Due to their nonlinear response and complex-ity, excitable cells (neurons, cardiac and othermuscle cells) and the molecules definingtheir functionality (ion channels and othertransmembrane proteins) have proven to befertile ground for quantitative engineeringapproaches aimed at understanding theirbehavior and their cellular and environmentalinteractions. The ability to predict and controlthe behavior of excitable-cell networks overspace and time, essential for fundamentalprocesses such as brain and heart function,remains a grand challenge in excitable-cellbiology. In the cardiovascular field, this isillustrated by failures of clinical trials withanti-arrhythmic drugs intended to counteractelectrical disturbances in the heart. Thesefailures can be attributed to inappropriatefocus on a single protein target and lack of a“systems understanding” in the therapeuticapproach. Consequently, the only availabletherapy for lethal cardiac arrhythmiasremains brute-force defibrillation: an electri-cal reset via strong electric fields.

Our long-term vision is to devise and validateintelligent model-based strategies to coun-teract life-threatening electrical disturbancesof the heart (cardiac arrhythmias); see figurebelow. To tackle the inherent complexity ofthis problem, we develop and bridge innova-tive in vitro and in silico models of excitable-cell networks for the learning and abstractionof their function, and for the synthesis andvalidation of distributed control via electricalstimuli. The specific aims of this researcheffort are:

Machine Learning of Excitable Cells.Development of automated learning tech-niques for identifying abstract yet accurate insilico models of ion channels and excitable-cell function using a novel class of hybridautomata we call Cycle-Linear HybridAutomata (CLHA). CLHA parameters are relat-ed directly to molecular properties, and cell-level models are extended to connected cellnetworks. Both deterministic and probabilis-tic approaches are employed.

Predictive Analysis of Excitable-CellNetworks. Development of model-basedmethods for system analysis that carry pre-dictive power for spatiotemporal interactionsamong excitable cells under varying interfa-cial conditions (electrical stimuli of variablefrequency and spatial distribution). The analy-sis relies on formulated CLHA single-cellmodels. Spatial clusters of such models,SCLHA, are derived by superposition.

Model-Based Control. Synthesis and in vitrovalidation of model-based distributed controlalgorithms to counteract in real time aberrantexcitation in cell networks via low-energyelectrical perturbations. Spatially-distributedstrategies target the control of characteristicspatiotemporal phenomena, and cases ofdisorganized activity, reducible to a problemof controlling coupled oscillators.

In Vitro Validation. Experimental validation ofin silico CLHA and SCLHA models and controllers developed in the above aims,through the application of hybrid in vitro test-ing platforms using live excitable-cell net-works, that can be sensed and actuated atmany locations. (NSF)

44 Medical

Algorithms forDetection of AtrialFibrillation

Ki H. Chon and Ernst Rader

Atrial Fibrillation (AF) is one of the most common cardiac arrhythmias. It afflicts 2-3million Americans and is estimated that 12-16 million individuals may be affected by2050 and at risk of significant mortality andmorbidity from this arrhythmia. Atrial fibrilla-tion is often asymptomatic and intermittent.When it is suspected one can perform ambu-latory monitoring in an attempt to documentthe arrhythmia. However, this approach istime consuming and not cost-effective forscreening asymptomatic populations.Accurate detection of AF is important sincetreatment modalities such as chronic antico-agulation and antiarrhythmic therapy, aswell as radiofrequency ablation carry theirown risks of serious complications.Given this rationale, we are developing a newalgorithm to detect accurately and in real-time, the presence of AF from either pulsepressure or ECG signals. Our AF detectionalgorithm is based on the widely acceptedview that the heartbeat interval series duringAF is random. Preliminary results based onrecordings from the MIT-Beth Israel HospitalAF database in 20 subjects highlight our initialsuccess in accurately detecting the presenceof AF; we achieved a sensitivity of 98.44%and specificity of 97.65%. (Funded internally)

Biomedical ContactInterface DiagnosisBased on NonlinearViscoelastic Model

Imin Kao

Throughout history, human inventions havealways sought to mimic the appearance,mobility, functionality, and intelligent opera-tion of humans and other living things. Thisfield of biologically inspired technology, hav-ing the moniker biomimetics, has evolvedfrom producing static copies of humans andanimals (as in artwork and sculptures) to theemergence of robots that operate with life-like behavior. When we observe the worldaround us, we see that the building blocks ofhuman creation are typically rigid, noncom-pliant molecules in the form of steel, con-crete, ceramics, plastics, etc. Nature, on theother hand, has taken a slightly differenttack, and has chosen the soft, compliant cellas its building block. Perhaps there is anadvantage inherent in the physical charac-teristics of soft tissue, specifically, the nonlin-ear viscoelastic behavior exhibited by com-pliant materials, including creep and relax-ation. Exciting opportunities exist in studyingthe interplay between creep and relaxation insoft and/or biomedical tissues, as well assensing, and determining if there is implicitinformation contained therein which willallow for more adaptable, scalable, andminiaturized intelligent sensors.

Viscoelasticity is a mechanical, and some-times chemical, phenomenon of time-depen-dent strain and stress. Various contact inter-faces with anthropomorphic end-effectorsand polymeric solids found in robots andmanipulators or in bio-tissues are intrinsical-ly viscoelastic. It is therefore important tomodel such behavior and to study the effectsof such time-dependent strain and stress onthe stability and sustainability of graspingand manipulation. Various models have beenproposed over the years to describe suchbehavior of time-dependent strain andstress. Furthermore, viscoelastic solids alsodisplay typically nonlinear elastic response.Built upon a variety of literature, a new andpractical latency model has been proposedfor the application of contact interface involv-ing viscoelasticity in robotics and biomedicalapplications. Latency model can describevarious features of viscoelastic materials,such as stress relaxation, creep, and materi-al clock. Based on the model of viscoelastic-ity, practical applications have been studiedin robotics as well as in bio-medical area.(NSF, JST)

CEWIT 45

46 Medical

Prostate Imaging

Arie Kaufman

Prostate cancer (CaP) is the number two can-cer killer among males. New methods areneeded for non-invasive imaging of theprostate and utilizing this information to locateCaP, leading to enhanced screening and forclinically-useful information be added to thecurrent set of techniques for CaP assessment.In this project we develop an exploratory, ini-tial-phase work towards a computer visualiza-tion system and a computer-aided detection(CAD) system for non-invasive interactive diag-nosis of CaP using MRI. This study involvesdeveloping virtual prostate examination tech-nologies using MRI data of the prostate; imple-menting effective interactive three-dimension-al visualization and CAD pilot systems; validat-ing the results of these systems including cor-relation with tissue findings of prostate wholemount. We employ high resolution MRI images,preferably endorectal MRI, from multipleacquisition modes, such as T1, T2, DWI (diffu-sion-weighted imaging) and/or MRSI (MRspectroscopic imaging). We use one datasetfrom UCLA that was provided by USRF with T1,T2 and DWI and over 100 datasets from ACRINstudy 6659 with T1, T2 and MRSI. (USRF)

Robotic Needle Biopsy

Yu Zhou

The objective of this research is to investigatenovel techniques to enable safe and efficientrobotic needle biopsy on moving organs suchas the kidney and lung. Needle biopsy is animportant technique for obtaining tissue speci-mens from lesions to facilitate microscopictumor diagnosis. Moving organs impose greatchallenge on conventional, manual needlebiopsy technique. Major advantages of roboticneedle biopsy technique include high precision,minimal invasion, high articulation and three-dimensional magnification. The proposedrobotic needle biopsy procedure uses a robotmanipulator to place the biopsy needle on a tar-geted lesion under the guidance of imagingmodalities such as CT and MRI. Specificresearch tasks include designing the needleplacement unit compatible with the designatedimaging modality, developing effective proce-dures for modeling the motion pattern of thetargeted lesion, studying algorithms for plan-ning optimal needle paths, investigating safeonline control methods for needle placement,and designing the human-in-the-loop roboticneedle biopsy system. (Funded Internally)

Virtual Colonoscopy

Arie Kaufman

A combination of computed tomography (CT)scanning and volume visualization technolo-gy, called virtual colonoscopy (VC), is rapidlygaining popularity. VC is poised to become theprocedure of choice in lieu of the convention-al optical colonoscopy for mass screening forcolon polyps – the precursor of colorectalcancer. The patient abdomen is imaged by ahelical CT scanner during a 40-second single-breath-hold. A 3D model of the colon is thenreconstructed from the CT scan by automati-cally segmenting the colon out of the rest ofthe abdomen and employing an "electroniccleansing" algorithm for computer-basedremoval of the residual material. The visuali-zation software allows the physician to inter-actively navigate through the colon using vol-ume rendering. An intuitive user interface withcustomized tools supports 3D measurements,"virtual biopsy" to inspect suspicious regionsand "painting" to help in visualizing 100% ofthe colon surface. Unlike conventional opticalcolonoscopy, VC is patient friendly, fast, non-invasive, more accurate, cost-effective proce-dure for mass screening of colon polyps. Thistechnology can also be applied to otherorgans, such as lungs (virtual broncoscopy),bladder (virtual cystoscopy), blood vessels(virtual AAA), etc. (NIH, NSF, ONR)

Computational Methodsfor Discovering VirulentProteins and Bio-engineered Threats

Michael Kifer and I.V. Ramakrishnan

Advances in recombinant DNA technologyhave opened up possibilities for productionof bio-engineered pathogens or their prod-ucts on scales that could make them formi-dable weapons of bio-terrorism. Only a limit-ed number of organisms and toxins havebeen designated as biological warfareagents. However, the possibility of producinggenetically engineered pathogens presents athreat. These may be chimeric protein mole-cules or benign molecules transformed intovirulent proteins, which could escape noticeor detection. Thus there is a critical need toidentify such bio-engineered toxins ahead oftime. We need to determine whether a giventoxin or its active site could be incorporatedinto another, otherwise non-toxic, protein. Inthis project, we are developing computation-al techniques and processes, and tools tosolve the above problems and help discoveradequate bio-defenses against chimericalproteins that can be bio-engineered into tox-ins. (ARO)

Rapid-CT: Real-Time 3D ComputedTomographicReconstruction UsingCommodity GraphicsHardware

Klaus Mueller

The recent emergence of various types offlat-panel x-ray detectors and C-armgantries now enables the construction ofnovel imaging platforms for a wide variety ofclinical applications. Many of these applica-tions require interactive 3D image genera-tion, which cannot be satisfied with inexpen-sive PC-based solutions using the CPU. Weexplore solutions based on commoditygraphics hardware (GPUs) to provide thesecapabilities. We have pioneered a novelstreaming CT framework that conceptualizesthe reconstruction process as a steady flowof data across a computing pipeline, updat-ing the reconstruction result immediatelyafter the projections have been acquired.Using a single PC equipped with a singlehigh-end commodity graphics board (theNVIDIA 8800 GTX), our system is able toprocess clinically-sized projection data atspeeds meeting and exceeding the typicalflat-panel detector data production rates,enabling throughput rates of 40–50 projec-tions/s for the reconstruction of clinically-sized data volumes. Apart from enabling fastpatient throughput and diagnosis, thestreaming CT framework also represents anexcellent platform for image-guided surgeryand diagnostic imaging of transient phenom-ena. A further, non-medical, application canbe inside rapid security scanners for luggageand freight. (NIH)

Emergency DepartmentError Detection System(EEDS)

Robert Kelly

The EEDS project is developing a system toidentify abnormal physical and laboratoryfindings and automatically notify the physi-cian and study coordinator of the occurrenceof Adverse Events (AES), typically throughwireless devices. Events and findings thatwould not be detected prior to patient dis-charge are of immediate interest. Amongthese events are clinical trials in whichpotentially eligible patients are identified and screened.

Real-time clinical data is provided to the sys-tem through both hospital records and net-work-accessible monitor data. At the heart ofthe system are components that address theidentification of abnormal findings in the ED,namely

1) Clinical data population - the clinical datastructures contained in EEDS are popu-lated by parsing hospital clinical datarecords;

2) Rules engine - clinical rules (e.g., abnor-mal ranges for serum potassium) arecoded in text-based XML documents,and are parsed to generate EEDS ruleobjects;

3) Alert system - when EEDS identifies anadverse event or other abnormality, itsends alerts to physicians through wire-less devices; and

4) Reporting system generates retrospec-tive reports based on data stored in thedatabase that allows physicians to fur-ther analyze and classify abnormal con-ditions along with the attending physi-cian's response. (EMF, HHS)

CEWIT 47

A Radio FrequencyIdentification Systemfor Prevention ofDenture Loss in LongTerm Care Facilities

Akshay Athalye

Loss of dentures is a frequent and expensiveproblem in long term care facilities. A typical100 bed facility typically spends close to$100,000 annually on lost denture replace-ment. A resident's nutritional intake suffersas a result of denture loss, causing discom-fort and deterioration in health. Today, longterm care facilities continue to suffer fromthis problem without the aid of a technologybased solution. Our research is directedtowards development of a Radio FrequencyIDentification (RFID) based system for pre-venting loss of dentures in long term carefacilities. The system will consist of special-ized RFID tags embedded into dentures, spe-cialized RFID reader modules for use in thefacilities and software for operation andmanagement of the system. Our system willnot only reduce operational costs, but willalso eliminate the discomfort, frustration anddeterioration in health that denture losscauses to facility residents. As a result, thesystem would greatly enhance the quality ofhealth care provided in long term care facili-ties. The proposed approach will result in asolution that will be cost effective, scalableand will operate without causing any disrup-tion to facility staff or resident behavior andwithout requiring additional skilled staff.Our system will consist of a passive tagembedded in the denture serving the pur-pose of both identification and detection, andspecialized reader modules for detectingthese denture tags. RFID is a rapidly emerg-ing technology for automatic remote identifi-cation of objects. Standard RFID systems arecomprised of tags/transponders that areattached to objects, and readers that remote-ly read the identification information con-tained in the tags.

Almost all RFID tag manufacturers in today'smarket develop tags for asset tracking in endto end supply chain and enterprise manage-ment systems. The shape and form factor ofthe tag antennas and the packaging of thesetags make it infeasible to implant them intodentures. Additionally, given the unique com-position and geometry of dentures, it is nec-essary to design unique tag antennas thatare optimized for this application.Development of such specialized “denturetags” is a major focus of our research.

Given the size and the setup of a typical facil-ity, having an omnipresent system wouldrequire extensive infrastructure installationor a large search staff that carries handheldreaders. Such a system would be economi-cally infeasible. Hence we follow theapproach of identifying the typical points ofloss for the dentures based on an analysis ofresident behavior using the experiencegained by the facility over the years. We findthat commercial, off-the-shelf reader mod-ules are not suited for seamless use at theidentified points of loss. We address thisproblem by designing specialized “wear-able” RFID reader modules for use at thepoints of loss. These modules provide reli-able, robust and efficient detection of thedenture tags without requiring any behav-ioral changes to the facility residents or staff.

This research effort will help to solve the veryserious problem of resident denture loss suf-fered by long term health care facilities. Thiswould result in a significant cost savings andwould reduce the inconvenience caused tothe residents and improve the quality ofhealthcare provided. (VA)

Self-Powered WirelessHealth MonitoringSystem

Goldie Nejat and Wendy Tang

In this project, we have designed an initialprototype for the sensory system of thewearable health monitoring devices in thearchitecture. The sensory system consists ofa wireless sensor node and a set of non-invasive physiological sensors. To addressthe significant issue of energy depletion forthe devices, which can lead to critical inter-ruptions in monitoring, we have proposed aflexible unique vibration-based energy har-vesting scheme to support our architecture.

Furthermore, for wireless communications,we are investigating the use of a novel MAC(Medium Access Control) protocol, the CPR(Cayley-Pseudo Random) protocol to supportsimultaneous transmission of large numberof users. We propose a novel protocol thatincorporates a “dense” graph as the underly-ing pattern for channel assignment in wire-less sensor networks. Each node of the sen-sor network is capable of transmitting to asmall number of nodes with a dedicated andassigned frequency channel. Such anassignment is based on the connection pat-tern of a pseudo random graph. Beforedeployment, each sensor node is pro-grammed to transmit and receive with a setof small and dedicated frequency channels.Once deployed, this frequency allocation isfixed. Each sensor node will only transmit,listen and receive messages with the allocat-ed frequency channels. Since each link isonly dedicated to a specific pair of sensornodes, there are almost no collisions, andhence minimal collision induced energywastes. Channels are divided according tofrequencies and a decentralized routingalgorithm is used. Global time synchroniza-tion is therefore avoided. (NSF)

48 Medical

Investigation intoInsertion of RFID TagInside a Pill

Milutin Stanacevic and Shmuel Einav

Drug uptake by patients often needs to betracked, especially in psychiatric patients,transplant patients and elderly people. Theaim of this proposal is to investigate a sys-tem containing RFID tag as additional partinserted in a pill for monitoring of ingestion ofmedicine and absorption into the body toinsure proper dosage control and usage. Theproposed system will be able to reliabledetect if the patient has taken a certain med-ication or not. The system will be designed tobe user friendly, cheap and safe.

Currently, radio-frequency identification(RFID) technology is being used for wide vari-ety of applications ranging from inventorycontrol to automatic tracking systems. Thefactors driving the technology are miniatur-ization and low cost which have made thetags ubiquitous. RFID system is composedout of two parts: RFID tag and RFID reader.Tag contains an antenna, a microchip andsometimes a battery. Unique identifying datais stored inside the microchip. Tag receivesan electromagnetic energy from the readerand sends radio waves back to the reader,with identifying data. Reader than receivesradio waves and interprets the tag’s data.

Tag types depend on the powering mechanism:

1) Active tag uses internal power for broad-cast (R/W)

2) Semi-active tag uses internal power for itselectronics (WO/R)

3) Passive tag relies on the reader for theirpower source (R)

Active and semi-active tags transmit theirdata up to 30m, while passive tags transmittheir data up to 6m. RFID system have foundfollowing uses in medicine: locating/trackingof medical stuff, patients, equipment, theftprevention, drug counterfeit prevention, RFIDimplants in humans (by VeriChip Corp) andtracking and identifying bottles of drugs (byOrion Pharmaceutical). (HSC, CEWIT)

Potassium IonSelective Electrodes

Perena Gouma

Recently the so-called all-solid-state potas-sium ion selective electrodes (ISE) havereceived more attention than the classicalelectrodes with internal filling solution. Thesedurable electrodes require less maintenanceand are easier to miniaturize.Among the sev-eral common types of all-solid-state potassi-um ISEs, conducting polymers based elec-trodes are promising because the electroac-tive properties of the conducting polymerscombined with the potassium recognitionmembrane can be used to convert chemicalinformation (potassium ion concentration)into electrical signals in the solid state.Conducting polymers in ISE can be intro-duced in two different ways. One is to com-bine conducting polymers with a traditionalionophore-based polymer matrix ion selec-tive membrane to form a two-layer mem-brane. In this case,the conducting polymerswork as the ion-to-electron transducer onlyand these conducting polymer materials arebased mainly on derivatives of polypyr-role(PPy), polythiophene or polyaniline(PANI) .Electroactive polymer polyaniline (PANI), it’sderivatives and it’s composites with celluloseacetate are employed as transducers to pro-duce an electronic output which could beused for monitoring K+ concentrationchanges in human fluids. We have inventedthe concept of a “band-aid” type sweat testfor measuring potassium ion levels fast,accurately, and potentially wirelessly. (HSC,CEWIT)

CEWIT 49

Combined Near andFar field UHF RFIDBased SpecimenInventory and Tracking System

Akshay Athalye

This research focuses on the development ofa system for reliable, robust automated loca-tion tracking and inventory management ofspecimen in hospitals. Currently, medicalspecimen tracking in most hospitals is beingdone manually. Not only is this processresource intensive, it is prone to human error.A real-time specimen tracking system willstreamline and automate the process. Thesystem will track specimens travellingbetween various locations such as theHospital’s Operating Rooms, Endoscopy,Radiology and the pathology and testinglabs. The goal of the system is to provideaccurate tracking to reduce the possibility ofmisplaced or lost specimen, enable automat-ed specimen inventory management as wellas enhance patient care and safety andboost staff efficiency and increase productiv-ity. Conventional bar code, RFID or wifi basedsystems do not provide a feasible and effi-cient solution to this problem. We propose anovel RFID based system, utilizing a combi-nation of near and far field communication,that overcomes the challenges faced by con-ventional systems to provide a cost-effectiveand scalable solution to the specimen track-ing problem.

The process of specimen transport begins atthe OR where specimen are put into specialcontainers in a medium consisting of preser-vatives such as ice, water or formalin.Systems for automated inventory manage-ment of specimens using bar codes or pas-sive RFID labels are available in the market.These systems involve affixing specimencontainers with bar codes or tags with preprogrammed IDs and associating the ids torelevant specimen information in a back end

database. Specimen labels are scanned atdispatch and receive stations by deployed orhandheld scanners. Although such a systemallows for some degree of automated inven-tory management, it does not provide thecapability of specimen location tracking.Present day commercial systems for assetlocation tracking in hospitals are based onuse of active RFID or wi-fi technologies.These systems involve active tags placed onobjects and wireless access points deployedalong the infrastructure. These access pointsdetect the active tags throughout the area ofcoverage and attempt to localize them usingtechniques based on received signal strengthor time difference of arrival. The size and costof an active tag, such tags cannot be affixedto each specimen. Moreover accurate loca-tion tracking requires a high density deploy-ment of access points which is also veryexpensive.

Our system is based on RFID technologyoperating in the UHF frequency band.Commercial UHF RFID systems operateunder the EPC Global Gen 2 standard. Usingthe same reader hardware and tag chipset,UHF RFID systems can operate in both thenear field and the far field by only changingthe antennas connected to the reader andtag chip. We use this unique feature of Gen 2compliant UHF RFID to develop a combinednear/far field system for the specimen track-ing problem. Our system uses near field UHFtags attached to individual specimen and farfield UHF tags deployed along the specimentravel path. Specimens will be transported ina specially developed box/bucket like devicethat we call the Specimen Carrier.

The specimen carrier will consist of an inte-grated RFID + wifi device. The specimen car-rier will have two types of antennas embed-ded into it:

1) Near field antenna on inside of carrier

2) Far Field antenna on outside of carrier.

The field of view of the near field antenna willbe limited to the inside of the carrier wherethe tagged specimens will be placed. The farfield antennas will be looking outward andwill read the far field tags deployed along thespecimen travel path. The wifi card on thecarrier will provide connectivity to the net-work and an ability to remotely query readthe contents of the carrier on demand. It iswell known that the performance of far fieldUHF tags suffers significantly in presence ofmetals and liquids.

Also, the size of most far field UHF tags isoften too large to fit on the most commonspecimen containers which are in the form ofsmall bottles, vials or test tubes. HighFrequency (HF) RFID tags operating usingnear field coupling can be used in the pres-ence of liquids, but most HF tags are alsolarge in size. Using near field UHF for thespecimen tagging gives us both the benefitsof good performance in presence of liquidsand chemicals and small form factor suitedto specimen containers of all shapes andsizes. Moreover, it also allows us to use thedual near/far field capability of Gen 2 RFID todevelop an elegant, robust and cost effectivesystem for the specimen tracking problem.(HSC, CEWIT)

50 Medical

LeadershipSatya SharmaExecutive [email protected]

Arie KaufmanChief [email protected]

Jacob SharonyDirector, Network Technologies [email protected]

Rong ZhaoDirector, Software Systems [email protected]

Samir DasDirector, Systems and Infrastructure [email protected]

Yuanyuan YangDirector, Communications and Devices [email protected]

Shmuel EinavDirector, Medical Division [email protected]

Scott Passeser Director, Industrial Outreach [email protected]

Researchers

Akshay Athalye [email protected]

Michael [email protected]

Tamara [email protected]

Tzi-cker Chiueh [email protected]

Ki [email protected]

Thomas [email protected]

Yuefan [email protected]

Petar [email protected]

Alex [email protected]

Dmitri [email protected]

Mikhail [email protected]

Monica Fernandez-Bugallo [email protected]

Jie Gao [email protected]

Perena Gouma [email protected]

Radu Grosu [email protected]

David Gu [email protected]

Himanshu [email protected]

Sangjin [email protected]

Peisen Huang [email protected]

Rob Johnson [email protected]

Imin Kao [email protected]

Rob Kelly [email protected]

Michael Kifer [email protected]

Annie [email protected]

Jon Longtin [email protected]

Joseph [email protected]

Klaus Mueller [email protected]

Goldie Nejat [email protected]

Luis Ortiz [email protected]

Michael [email protected]

Hong Qin [email protected]

C.R. Ramakrishnan [email protected]

I.V. Ramakrishnan [email protected]

Tom Robertazzi [email protected]

Dimitris Samaras [email protected]

Lori [email protected]

Tony Scarlatos [email protected]

R Sekar [email protected]

Radu Sion [email protected]

Steve Skiena [email protected]

Scott A. Smolka [email protected]

Milutin Stanacevic [email protected]

Amanda [email protected]

Scott [email protected]

Muralidhara Subbarao [email protected]

Wendy [email protected]

Xin Wang [email protected]

David Warren [email protected]

Jennifer Wong [email protected]

Erez Zadok [email protected]

Yu Zhou [email protected]

Wei [email protected]

CEWIT 51

Staff and Researchers

Center of Excellence in Wireless and Information Technology

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Major Research Areas• Algorithms and Languages• Architecture• Communications• Concurrent and Distributed Systems• Data Management and Analysis• Embedded Systems

• Graphics and Visualization• High Performance Computing• Human Computer Interaction• Intelligent Information Systems• Mobile Systems Design• Cyber-Security

• Sensor Networks• Signal Processing• Software Applications• Visual Computing• VLSI Systems Design• Wireless Networks

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