part2_collaboration in ds ds+ai,coprba queue

8/7/2019 part2_collaboration in ds DS+AI,Coprba Queue

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Part 2Collaboration in the 21st Century :Models and Theoretical Foundations

Dr. Y.V. Ramana Reddy

Dr. Sumitra Reddy

Vijayanand BharadwajLane Dept. of Computer Science and Electrical Engg.

West Virginia University

USA

August 2005


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August 2005 SIPLab (CERC, WVU) 2

Part 2: Overview

Foundations of Collaboration Science (CSCW)Confluence of Various Disciplines

Primary Disciplines

Management ScienceDistributed Computing

Artificial Intelligence

A Review of FoundationsDistributed Computing

Work, Organization & Management


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Aspects of Collaboration


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Multiple Perspectives of Collaboration

Human User Perspectivesfor example

Sociology

Psychology

Linguistics

Group Perspectivefor example:

Organization and Management Science

Economics

Technology Perspectivefor example:

Distributed Computing

Human-Computer Interaction

Information Systems & Knowledge Engineering

Artificial Intelligence

Pervasive and Ubiquitous Computing


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Multiple Perspectives of Collaboration

There are many more.

Can You Think of Any Others ?


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Primary Disciplines


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Distributed Computing

Foundations of Collaboration

Collaboration

Science

Artificial IntelligenceManagement

Science


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A Review of Foundations

1. Technical Foundations:

DISTRIBUTED COMPUTING+ ARTIFICIAL INTELLIGENCE +Associated Fields ( Information Systems, Human Computer-Interaction & others Implicit )

2. Work and Organization Theory (Management

Science)

Primarily: WORK PROCESS MODELING

WORK PROCESSSPECIFICATION


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Technology - A Myriad of Terms!

HTTP

Semantic WEB

WWW

WSDL

SQL

KQML

RDF

LINUX SSL

VoiceXML

Existing Technologies: Making Sense of it all.

CORBAXML

RDBMS


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Technical Foundations

Models and Concepts

Theoretical paradigms and ideas

Issues

Key aspects and issues related to the above concepts

Methodologies

Concrete solutions and techniques to realize the above concepts

and deal with their issues Substrates

Enablers to implement the methodologies

Medium

Mediums of Communication

Technology (Standards)Real-World Implementations of the above concepts and

corresponding methodologies

Applications and Tools:

Applications built using the above technology


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Technology Drivers

DistributedComputing

+

Artificial

Intelligence

PERVASIVECOMPUTING MOBILE

COMPUTING

SEMANTICWEB

GPS

INTERNET

NETWORKSWIRELINE

&WIRELESS

INTELLIGENTAGENTS


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Models and Concepts

Theoretical paradigms and ideas

Issues


Methodologies

Concrete solutions and techniques to realize the above concepts and deal

with their issues Substrates


Medium


Technology (Standards)Real-World Implementations of the above concepts and corresponding

methodologies




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Models & Concepts

Client Server ( 2 to N tier)

Peer-to-Peer P2PService Oriented ArchitectureVirtual MachineHigh Performance Computing (Parallel Computing)Relational Data

Meta-DataMobile ComputingPervasive & Ubiquitous ComputingIntelligent AgentsExpert Systems

Knowledge BaseOntologyKnowledge EngineeringHuman-Computer-Interaction & Usability


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NETWORK

Client-Server Paradigm

Client: A processes that initiates communication with another

process (Server) to request resources and/or services.

Servers: A process that responds to requests from other

processes (clients).

Server Process on HostServer Response

Client Request

Client Process on Host


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Client-Server Architecture can be as simple as two processes

communicating ( 2- tier)


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There may be have many tiers depending on how the requested resources

and services are accessed ( N-tier)


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P2P Paradigm

A process can be both a client and server.

no always-on server

arbitrary end systems

directly communicate

peers are intermittentlyconnected and change IP

addresses

Highly scalable

But difficult to manage


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Hybrid of client-server and P2P

Napster File transfer P2P

File search centralized: Peers register content at central server

Peers query same central server to locate content

Instant messaging Chatting between two users is P2P

Presence detection/location centralized:

User registers its IP address with central server when it comesonline

User contacts central server to find IP addresses of buddies


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Service Oriented Architecture

A Service is an implementation of a well-defined business

functionality that operates independent of the state of any otherService defined within the system.

Services have a well- defined set of interfaces and operate through apre-defined contract between the client of the Service and theService itself. (http://javaboutique.internet.com/tutorials/serv_orient/ )

Services can be reused by being invoked in different contexts.

Services can thus evolves independently of its client entities.

Services can be dynamically:

Discovered, Invoked, & Interacted

Without worrying about the details of the Service.

Example: WEB SERVICES


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Virtual Machine

An entity that sits on top of the native Operating System on

which programs can run that would normally be

incompatible with the native system.

The Key to Interoperability that is essential for Collaboration

Compile-Once -- Run-Anywhere !!

Example: Java Virtual Machine


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High-Performance Computing

The ability to harness computing resources such as machine

cycles and memory, and thereby obtain greater computing

capability.

Conventionally realized through parallel-architectures on one

entity example: Super Computer Architectures

Recently realized by incorporating hosts across a network

Clusters: Multiple computing nodes across local Ethernet

GRIDS: Multiple computing nodes across the Internet


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Databases and Meta-Data

Databases store data that is used and an created as a result

of work processes. Relational Databases, Object-Oriented

Databases and Hierarchical Databases are some models.

Meta-Data: Addition of Data attributes to describe Information

Enable information to be discovered and used by various

clients in a variety of ways.


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Mobile Computing

The ability to access computational resources (data, programs

and services) while mobile without being tied to a particular

computing node or network.

Possible by the evolution of hand-held computing devices that

can be used as computing nodes to run programs.

Client Processes running on these devices can access Server

Processes, via wireless networks.


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Pervasive or Ubiquitous Computing

An environment where resources and services that require

computing and connectivity are always available in an

unobtrusive manner through embedded devices in

clothing, tools, appliances, cars, homes and many others

!!!!!


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Some Examples: (from http://www.fincher.org/tips/web/Pervasive.shtml)

1. Medications (what if every pill had a UPC code on it?)

2. Home interaction: The networked coffee pot/an alarm clock sync'd

with Outlook / Electricity Peak Conservation/Thermostat/Hot Water

Heater connected via wireless network (security issues)

3. Car: Schedule oil change seamlessly w/ garage; maps; traffic; kid

movies streamed to back seat ("Only if its quiet back there")

4. Finding Possessions: "Dude, where's my dog?"

5. Distribution: "Where is my package?"


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Some Examples: (from http://www.fincher.org/tips/web/Pervasive.shtml)

6. Vending: improved routing, re-supply, ordering; price changes pushed

to machines

7. Flight Schedules: Your phone rings. Its the computer at American

Airlines. Your flight departure is delayed by 20 minutes.

8. Networked coffee shop: Wi-Fi at StarBuck's and Schlosky's

9. Location: finding friends at the mall (or hiding from) !!

OTHER EXAMPLES ???


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Knowledge-Based Systems

( Expert Systems)

A system that uses knowledge specific to a problem

domain to provide answers. This knowledge is obtained

from experts in that field.

Uses knowledge of a domain as a human expert would and

emulates human performance, hence called knowledge-intensive or strong-method of problem solving.

The techniques used in representing knowledge and

inference are used in a wide variety of collaborativesystems such as adaptable workflow systems.


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Expert Systems Architecture

Reproduced from [Luger G. 2005]


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Models and Concepts

Theoretical paradigms and ideas Issues


Methodologies




Medium







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Issues

Goals of Distributed Computing [ Tannenbaum ] [Popstojanoava 2005]

1. Connecting users and resources:

Access remote resources and share them in a controlled way.

2. Transparency

Distributed system presents itself to users and applications as if itwere only a single computer

3.Openness

Distributed system offers services according to standard rules thatdescribe the syntax and semantics of these services

4. Scalability

Ability to expand


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Connecting Users & Resources

Resources can be virtually anything: printers, computers,

storage facilities, data, files, Web pages, networks

With respect to connectivity and sharing Security and Privacy

are very important issues.


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Transparency in a Distributed System

Different forms of transparency in a distributed system.

Transparency Description

AccessHide differences in data representation and how aresource is accessed

Location Hide where a resource is located

Migration Hide that a resource may move to another location

Relocation Hide that a resource may be moved to another locationwhile in use

ReplicationHide that a resource may be shared by several competitiveusers

ConcurrencyHide that a resource may be shared by several competitiveusers

Failure Hide the failure and recovery of a resource

PersistenceHide whether a (software) resource is in memory or ondisk


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Openness

Distributed Systems formalize interaction in terms ofProtocols to ensure

compatibility.

Services are generally specified through interfaces, which are often

described in an Interface Definition Language (IDL)

Nearly always only the syntax is captured (names of the functions,

types of the parameters, return values, possible exceptions that can

be raised, and so on)

Proper specification should be complete and neutral

Important forInteroperability and Portability

Specification should be Flexible easy to configure, change, and extend


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Scalability

Scalability problems manifest as performance problems

due to limited capacity of servers and networks

Some Techniques for Scaling

Hiding communication latencies

Distribution

Replication and Caching


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Scalability

Hiding Communication Latencies:

Batch Processing, Parallel Processing,Client-Side Processing

1.4

The difference between letting:

A server OR A client check forms as they are being filled


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Scalability

Distribution Technique:

An example of dividing the DNS name space into zones.


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Scalability

Replication: increases availability and improves

performance

Caching: special form of replication; making a copy of the

resource in the proximity of the client

Replication and caching lead to consistency problems


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Models and Concepts



Methodologies




Medium







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Methodologies

Remote Procedure Call

Object Oriented CORBA

Message Queuing Systems

Hyper-linking

Markup Language


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A Remote Procedure Call (RPC) is a protocol that allows a

computer program running on one host to cause code to beexecuted on another host without the programmer needing

to explicitly code for this.

When the code in question is written using object-oriented

principles, RPC is sometimes referred to as remote

invocation or remote method invocation.


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Steps of a Remote Procedure Call

1. Client procedure calls client stub in normal way

2. Client stub builds message, calls local OS

3. Client's OS sends message to remote OS

4. Remote OS gives message to server stub

5. Server stub unpacks parameters, calls server

6. Server does work, returns result to the stub

7. Server stub packs it in message, calls local OS

(Continued)


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Steps of a Remote Procedure Call

(continued)

Server's OS sends message to client's OS

Client's OS gives message to client stub

Stub unpacks result, returns to client


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In order to allow servers to be accessed by differing clients, a

number of standardized RPC systems have been created.

Most of these use an interface description language (IDL) to

allow various platforms to call the RPC.

Examples of such systems:

Sun RPC (sometimes called ONC RPC),

Distributed computing environment (DCE),

Microsoft's DCOM (and ActiveX), which is based in part on

DCE

and CORBA.


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RPC using XML as the IDL, and HTTP as the network

protocol.

The advantage of this system, known as WEBSERVICES, issimplicity and standardization, the IDL is a text file that is

widely understood, and HTTP is ubiquitous.

An example of such an RPC system is:

SOAP (Simple Object Access Protocol) developed in turn from

XML-RPC.


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CORBA

Common Object Request Broker Architecture (CORBA), is a

standard for software components.

The CORBA standard is created and controlled by the ObjectManagement Group (OMG).

It defines APIs, communication protocol, and object/serviceinformation models to enable heterogeneous applicationswritten in various languages running on various platforms tointeroperate.

CORBA therefore provides platform and location transparencyforsharing well-defined objects across a distributedcomputing platform


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CORBA ORB Architecture

Reproduced From [Schmidt, D.]


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[Reproduced From [Schmidt, D.]

Object -- This is a CORBA programming entity that consists of anidentity, an interface, and an implementation, which is known as aServant.

Servant -- This is an implementation programming language entity thatdefines the operations that support a CORBA IDL interface. Servantscan be written in a variety of languages, including C, C++, Java,Smalltalk, and Ada.

Client -- This is the program entity that invokes an operation on anobject implementation. Accessing the services of a remote object

should be transparent to the caller. Ideally, it should be as simple as calling a method on an object.

The remaining components in the Figure help to support this level oftransparency.


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Object Request Broker(ORB) -- The ORB provides a

mechanism for transparently communicating client requeststo target object implementations.

The ORB simplifies distributed programming by decouplingthe client from the details of the method invocations.

This makes client requests appear to be local procedurecalls.

When a client invokes an operation, the ORB is responsiblefor finding the object implementation, transparentlyactivating it if necessary, delivering the request to theobject, and returning any response to the caller.


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ORB Interface -- An ORB is a logical entity that may be

implemented in various ways (such as one or moreprocesses or a set of libraries).

To decouple applications from implementation details, the

CORBA specification defines an abstract interface for anORB.

This interface provides various helper functions such as

converting object references to strings and vice versa, andcreating argument lists for requests made through the

dynamic invocation interface described below.


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CORBA IDL stubs and skeletons -- CORBA IDL stubs

and skeletons serve as the ``glue'' between the client andserver applications, respectively, and the ORB.

The transformation between CORBA IDL definitions and

the target programming language is automated by aCORBA IDL compiler.

The use of a compiler reduces the potential for

inconsistencies between client stubs and server skeletonsand increases opportunities for automated compiler

optimizations.


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Dynamic Invocation Interface (DII) -- This interface allows

a client to directly access the underlying requestmechanisms provided by an ORB.

Applications use the DII to dynamically issue requests to

objects without requiring IDL interface-specific stubs to belinked in.

Unlike IDL stubs (which only allow RPC-style requests), the

DII also allows clients to make non-blocking deferredsynchronous (separate send and receive operations) and

oneway(send-only) calls.


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Dynamic Skeleton Interface (DSI) -- This is the server

side's analogue to the client side's DII.

The DSI allows an ORB to deliver requests to an object

implementation that does not have compile-time knowledge

of the type of the object it is implementing.

The client making the request has no idea whether the

implementation is using the type-specific IDL skeletons or isusing the dynamic skeletons.

CORBA ORB A hi


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Object Adapter-- This assists the ORB with delivering

requests to the object and with activating the object.

More importantly, an object adapter associates object

implementations with the ORB.

Object adapters can be specialized to provide support for

certain object implementation styles (such as OODB object

adapters for persistence and library object adapters for

non-remote objects).

M Q i


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Message Queuing

Enable Asynchronous Communication among processes.

Four combinations for loosely-coupled communications using queues.

M Q i G l A hi


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Message Queuing: General Architecture

The relationship between queue-level addressing and network-level

addressing.

M Q i G l A hit t


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Message Queuing: General Architecture

The general organization of a message-queuing system with

routers.

M Q i


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Message Queuing

Primitive Meaning

Put Append a message to a specified queue

GetBlock until the specified queue is nonempty, and remove the firstmessage

PollCheck a specified queue for messages, and remove the first. Neverblock.

Notify

Install a handler to be called when a message is put into the

specified queue.

Basic interface to a queue in a message-queuing system.

H Li ki


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Hyper-Linking

A hyperlink (or simply a link), is a reference in a hypertext

document to another document or other resource.

Similar to a citation in literature.

However, combined with a data network and suitable access

protocol, it can be used to fetch the resource referenced.

This can then be saved, viewed, or displayed as part of the

referencing document.

A key part of the foundation of the World Wide Web !

M k L


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Markup Language

A mechanism to add meta-information to a body of information.

A language that can be used to annotate or markup other information.

A markup language combines text and extra information about the text.

The extra information, for example about the text's structure or

presentation, is expressed using markup, which is intermingled with the

primary text.

Example: Extensible Markup Language (XML)

HyperText Markup Language (HTML)

and many others

T h i l F d ti


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Models and Concepts



Methodologies




Medium






S bstrates


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Substrates

Distributed Computing Systems operate over various

substrates:

Local Area Networks which can form Intranets

InternetThe public Internet which is the network of networks.

Ubiquitous in its reach across the world

An example of Wide-Area Networking.

Grids

Networks used to connect high-performance computingnodes. Grids may use the Internet or dedicatedinfrastructure.



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Models and Concepts



Methodologies




Medium


Technology (Standards)Real-World Implementations of the above concepts andcorresponding methodologies



Mediums


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Mediums

Mediums connect hosts to create substrates.

Wireline

Computer Networks using media such as copper twisted pair and or

fiber optics

Telephone landline networks

Wireless

Wireless LANS, Cellular Phone networks, Satellites



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Models and Concepts



Methodologies




Medium


Technology (Standards)Real-World Implementations of the above concepts andcorresponding methodologies



Technology & Standards


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HTTP (HyperText Transfer Protocol)

HTTP is a request/response protocol between clients and servers.

An HTTP client, such as a web browser, typically initiates a request by

establishing a TCP connection to a particular port on a remote host

(port 80 by default).

An HTTP server listening on that port waits for the client to send a request

string with elements specified in the protocol.

Upon receiving the request string (and message, if any), the server sends

back a response string, and a message of its own, the body of which is

perhaps the requested file, an error message, or some otherinformation.



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Java

High-Level Language that compiles as bytecodes that can run on anyplatform with the Java Virtual Machine

J2EE (Java 2 Platform Enterprise Edition):

A set of specifications and platform for creating N-Tier client-serverapplications by exploiting the notion of component reuse.

Components are distributed across the client , presentation layer (JavaServer Pages & Java Servlets), business logic layer and data accesslayer ( Enterprise Java Beans)

Specifications deal with managing all aspects of component life-cycle andtransactions.



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RDBMS (Relational Database Management Systems):

Present the data to the user as relations (a presentation in tabular form, i.e. as acollection of tables with each table consisting of a set of rows and columns, cansatisfy this property)

Provided relational operators to manipulate the data in tabular form viz. Add,modify, delete, update etc.

XML (Extensible Markup Language)An implementation of the Markup Language Concept. Derived from StandardGeneralized Markup Language (SGML)

LDAP (Lightweight DirectoryAccess Protocol)LDAP defines a protocol for updating and searching directories running over

TCP/IP.LDAP has been designed for working X.500 directories.

X.500 is the set of ITU-T computer networking standards covering electronicdirectory services such as white pages, Knowbot and whois.



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Web Services:

A Web service is a collection of protocols and standards used for

exchanging data between applications or systems.

Software applications written in various programming languages and

running on various platforms can use web services to exchange data

over computer networks like the Internet in a manner similar to inter-

process communication on a single computer.

This interoperability (e.g., between Java and Python, or Windows and

Linux applications) is due to the use of open standards.



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Web Services Architecture (1)



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Web Services Architecture (2)

XML & SOAP:All data to be exchanged is formatted with XML tags. The encoded

message is transmitted through a transport protocol such as SOAP,JAX-RPC, or XML-RPC.

WSDL (Web Services Description Language):The public interface to the web service is described by WSDL. This is an

XML-based service description on how to communicate using the webservice.

UDDI (Universal Description, Discovery, andIntegration)The web service information is published using this protocol. It should

enable applications to look up web services information in order todetermine whether to use them



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WAP (Wireless Application Protocol)

Wireless Application Protocol (WAP) is an open international standard forapplications that use wireless communication, for example Internetaccess from a mobile phone.

WAP was designed to provide services equivalent to a Web browser withsome mobile-specific additions, being specifically designed to addressthe limitations of very small portable devices.



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Bluetooth

Bluetooth is an industrial specification for wireless personal area networks

(PANs).

Bluetooth provides a way to connect and exchange information between

devices like personal digital assistants (PDAs), mobile phones, laptops,PCs, printers and digital cameras via a secure, low-cost, globally

available short range radio frequency.

Bluetooth lets these devices talk to each other when they come in range,

even if they are not in the same room, as long as they are within up to100 metres (320 feet) of each other, dependent on the power class of

the product.



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Wi-Fi ("Wireless Fidelity)

It is a set of product compatibility standards for wireless local areanetworks (WLAN) based on the IEEE 802.11 specifications.

Wi-Fi was intended to be used for mobile devices and LANs, but is nowoften used for Internet access.

It enables a person with a wireless-enabled computer or personal digitalassistant (PDA) to connect to the Internet when in proximity of anaccess point.

The geographical region covered by one or several access points is called

a hotspot.



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Models and Concepts



Methodologies




Medium


Technology (Standards)

Real-World Implementations of the above concepts andcorresponding methodologies

Applications and Tools


Applications


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Applications

World Wide Web

An application whose foundations are based on

client-server model, the Internet, hyperlinks, HTTPprotocol and other key elements.

Unprecedented impact on Collaboration !

Applications


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Applications

World Wide Web

Can we enumerate the ways the WWW haschanged our lives ?

Applications


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Applications

World Wide Web Web page consists ofobjects

Object can be HTML file, JPEG image, Java applet, audio

file,

Web page consists ofbase HTML-file which includes

several referenced objects

Each object is addressable by a Uniform Resource Locator

Example URL:

www.someschool.edu/someDept/pic.gif

host name path name

Applications


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Applications

World Wide Web Web page consists ofobjects

Object can be HTML file, JPEG

image, Java applet, audio file,

Web page consists ofbase HTML-

file which includes several

referenced objects

Each object is addressable by a

Uniform Resource Locator

Example URL:

www.someschool.edu/someDept/pic.gif

host name path name

PC runningExplorer

Serverrunning

Apache Webserver

Mac runningNavigator

Applications


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Applications

Semantic Web( from http://infomesh.net/2001/swintro/)

The Semantic Web is a mesh of information linked in a way

as to be easily processed by machines, on a global scale.

Information is represented, identified and stored on the WWW

in a manner by which programs can search and access it

without human intervention.

Information is not just linked but meanings are provided to the

link.

Applications


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Applications

Semantic Web: Enabling Standards and Technology

( Tim Berners-Lee http://www.w3.org/2002/Talks/04-sweb/Overview.html)

Applications


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Applications

Semantic Web:URI & Unicode: Actual data and identifier.

XML & Namespaces: XML based annotations to describe data

RDF & RDF Schema Layers: (Resource Description Framework)

A standard for describing information on the Web using tuples. This allows

information to be described in a machine-readable form.

RDF described relationships between information.

Information can be retrieved by searching based on these relationships.

Applications


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Applications

Semantic Web: ArchitectureOntology Layer:More meta-information, such as Transitive property Unique,

Unambiguous, Cardinality, etc

Rules Layer:

General purpose rules languages that allow query and filtering.

Rules layer allows form of Proof without full Logic layer.

Logic Layer:

Universal language for monotonic logic to inference about the information.

Proof & Trust Layers:

A flexible language to express existing systems such that theirtrustworthiness can be evaluated by programs.

Signature and Encryption:

Essential elements in Securing the layers.

Applications


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Applications

Oracle 9iAS: Oracles Application Server that implements the

J2EE architecture specifications.

JBoss: Another implementation of the J2EE architecture

MySQL: An implementation of the RDBMS technology

Groupware Systems such as:

Lotus Server & Notes

Microsoft Exchange,Microsoft Project

eGroupware

Novells GroupWise

IBM WebSphere Workflow System and MANY OTHERS !

Work & Organization Theory


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o & O ga at o eo y

Some Prominent Theories about Group Work([Borghoff & Schlichter])

Conversation Networks & Speech Act Theory:

This theory seeks to model group process in terms of

conversations among participants. The notion of speech asan action stems from Speech-Act Theory.



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Some Prominent Theories about Group Work[Borghoff & Schlichter]

Coordination Theory (Malone & Crowston)

Coordination can be seen as the process of managing dependencies amongactivities Malone & Crowston

This theory formalizes dependencies between activities and

provides a framework to analyze and evaluate different

coordination approaches.

Coordination is divided into four basic components: goals,

activities, actors and dependencies.



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Some Modeling & Specification Formalisms[Oren and Haller 2005], [Kim and Paik 1997], [Reijers Hajo, A. 2003]

Petri Nets

Provide formal semantics to model workflows and a graphical

notation to express them.

Consistent with the task-oriented nature of workflow.

Allows for a clear distinction between the structure of the

workflow and its dynamic state.

Supports notion of concurrency.



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Some Modeling & Specification Formalisms

Information Control Nets (ICN)

A mathematical formalism designed to graphically model work

processes.

Unlike Petri Nets ICN were specially created for business

procedures.

Here each procedure is defined by a set of objects ( such as

people, documents ) and set of relations ( precedence and

data access) which link these objects.The basic elements are activity, procedure, actor, mechanism

and policywhich are modeled as a control flow graph.



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Yet Another Workflow Language (YAWL)

YAWL is based on Petri nets (workflow nets).

However has additional mechanisms for direct and intuitive

modeling of all workflow patterns.

YAWL can be mapped to Petri nets, but has an independent

semantics.

A YAWL specification is a hierarchical extended workflow net,

consisting of tasks (transitions)and conditions (places).

Tasks are either atomic or composite.



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Temporal LogicTemporal logic is a generic logic for representing and

reasoning about temporal information.

Widely used for formal specification and verification ofconcurrent and reactive programs.

Used to model inter-task dependencies in workflows usingcomputational tree logic, a temporal logic variant.

The approach deals with specifying inter-task dependencies in

a multi-database environment, in which certain transactionalproperties of task executions should be ensured.



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Transaction Logic

Has been used for modeling, executing and reasoning

about workflows.

It is an extension of classical predicate logic which provides

a logical foundation for state changes in databases and logic

programs.

A workflow is specified as a set of formulas that describe

dependencies between tasks.

Tasks are modeled using predicates, they can be either

atomic or be defined as a sub-procedure (this allows for

compositional workflow modeling).

Summary


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y

Advances in Various Disciplines (primarily Management

Science, Distributed Computing and ArtificialIntelligence) have had a deep impact on the course ofCollaboration

Design and Development of Collaboration Systems mustleverage this knowledge in devising effective solutions !

References & Acknowledgement


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We would like to acknowledge the following sources of

information on which this presentations contents arebased.

Text and pictures have been reproduced as is or withmodifications from the sources below.

1. Chapter 2: Application Layer Presentation SlidesComputer Networking: A Top Down Approach Featuring the Internet, 3rdedition. Jim Kurose, Keith RossAddison-Wesley, July 2004.All material copyright 1996-2004J.F Kurose and K.W. Ross, All Rights Reserved

2. Slides from http://www.cs.vu.nl/~ast/books/ds1/Web Site to book Distributed Systems: Principles and Paradigms, Andrew S.

Tanenbaum , Maarten van Steen

Prentice Hall (India) ISBN: 81-203-2215-0



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(Continued)

3. Lecture Notes on Distributed Systems by Dr.Katerina Goseva-Popstojanova(LDCSEE, WVU)

http://www.csee.wvu.edu/~katerina/Teaching/CS-757-Fall-2004/Notes-CS-757-

Fall-2004.htm)

4. [Luger, G. 2005] Artificial Intelligence Structures and Strategies for Complex

Problem Solving , - George F Luger, 5th Edition, Addison Wesley, 2005, ISBN032126319

5. From Douglas C Schmidt Tutorial on CORBA

http://www.cs.wustl.edu/~schmidt/corba-overview.html

6. [Borghoff & Schlichter]: Computer Supported Cooperative Work: Introduction to

Distributed Systems, Springer-Verlag 1998, ISBN: 3-540-66984-1.

7. WikiPedia -- Web Encyclopedia. http://www.wikipedia.org



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(Continued)

8. [Oren & Haller 2005]Formal frameworks for workflow modelling

Eyal Oren Armin Haller DERI Technical Report 2005-04-07, April 2005

Retrieved from www.deri.at/publications/techpapers/documents/DERI-TR-2005-04-07.pdf

9. [Kim and Paik 1997] Practical Experiences and Requirements on Workflow

Kwang Hoon Kim & Su-Ki Paik, published in Coordination Technology for

Collaborative Applications eds. Wolfram Conen and Gustaf Neumann, Lecture

Notes in Computer Science Vol 1364, 1997.

10. [Reijers Hajo, A. 2003] Workflow Modeling Chapter 2 in Design and Control

of Workflow Processes Business Process Management for the ServiceIndustry, Lecture Notes in Computer Science, Vol.2617, 2003 Springer.

Questions & Discussion


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Thank [email protected]

[email protected]

[email protected]

SIPLab: Smart Internet Programming Laboratory

http://siplab.csee.wvu.edu

CERC: Concurrent Engineering Research Centerhttp://www.cerc.wvu.edu

LDCSEE: Lane Dept. of Computer Science & Electrical Engg. at WestVirginia University, USA

http://www.csee.wvu.edu

part2_collaboration in ds ds+ai,coprba queue

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