smart materials, nano- and micro-smart systems• mixed analog/rf design • circuits for wireless...

1SPIE • spie.org/events/aucall • Tel: +1 360 676 3290 • Fax: +1 360 647 1445 • [email protected]

Call For Papers

Smart Materials, Nano-and Micro-Smart Systems10-13 December 2006 University of Adelaide • Adelaide, Australia

Symposium Chairs:Joe G. Shapter, Flinders Univ. of South Australia

(Australia)Vijay K. Varadan, Univ. of Arkansas (USA)Derek Abbott, Univ. of Adelaide (Australia)

Smart Materials

Smart Structures, Devices,and Systems

Nano- and Microtechnology:Materials, Processes,Packaging, and Systems

Biomedical Applications ofMicro- and Nanoengineering

Complexity and NonlinearDynamics

Call For Papers

Publish your work • Hear the latest research • Network with your peers

2 SPIE • spie.org/events/aucall • Tel: +1 360 676 3290 • Fax: +1 360 647 1445 • [email protected]

Plan now to Participate!This symposium gives you the opportunity for in-depth communication with researchers anddevelopers in smart materials, smart structures, smart micro- and nanoelectronics devices andsystems, nano- and microtechnology with special emphasis on packaging and integration of MEMSand NEMS for diverse application areas. One full conference will be devoted to biomedicalapplications like bio-surveillance systems. These fields are multidisciplinary and make extensiveuse of micro- and nanofabrication technologies. Exciting new developments exist in nanomaterials,sensors and actuators, as well as in the design and application of these systems.

This symposium attracted over 350 submissions from 27 countries when held in Sydney in 2004.We look forward to welcoming you to the University of Adelaide this December.

Symposium Chairs


Joe ShapterFlinders Univ. of SouthAustralia (Australia)

Vijay K. VaradanUniv. of Arkansas (USA)

Derek AbbottUniv. of Adelaide(Australia)


Call For Papers

Smart Materials IV (AU101)Conference Chair: Nicolas Voelcker, FlindersUniv. of South Australia (Australia)Cochair: Alan R. Wilson, Defence Science andTechnology Organisation (Australia)

Introduction

This multidisciplinary conference covers a wide scopeof topical smart materials issues. The conference willbring together university, industry, and governmentresearchers to discuss the present state of present,emergent, and future directions in the area of smartmaterials particularly in the context of microelectronicsand MEMS. With advancement in science, increasinginterest in the interfaces between advancedtechnologies, biological and quantum domainsbecome intensified—all five parallel conferences in thissymposium welcome this perspective.

Scope• piezoelectrics• ceramics• composites• thin films• plasma treated surfaces• nanoparticles• nanorods• sol-gel• smart polymers• nanoparticle embedded polymers• materials for polymer electronics• conducting polymers• polymer actuators• nanostructured materials• self-organized nanomaterials• active materials• stimuli-responsive materials• self-healing materials• energy harvesting materials• morphing materials• shape-memory materials• materials for quantum devices and quantum

computation• materials for photonics devices• MOEMS materials• MEMS materials• NEMS materials.

Smart Structures, Devices, andSystems III (AU102)Conference Chair: Said F. Al-Sarawi, The Univ.of Adelaide (Australia)Cochairs: Vijay K. Varadan, Univ. of Arkansas;Neil Weste, NHEW R&D Pty, Ltd. (Australia)Program Committee: Derek Abbott, The Univ.of Adelaide (Australia); Mahmoud A. Al-Qutayri, Etisalat Univ. College (United ArabEmirates); Abdesselam S. Bouzerdoum, Univ.of Wollongong (Australia); Sorin D. Cotofana,Technische Univ. Delft (Netherlands); BernardCourtois, TIMA Lab. (France); Paul D.Franzon, North Carolina State Univ. (USA);Manfred Glesner, Technische Univ. Darmstadt(Germany); Hedley J. Hansen, DefenceScience and Technology Organisation(Australia); Sung-Mo Kang, Univ. of California/Santa Cruz (USA); Stefan W. Lachowicz, EdithCowan Univ. (Australia); Alireza Moini,Silverbrook Research Pty. Ltd. (Australia);Ampalavanapillai Nirmalathas, The Univ. ofMelbourne (Australia); Saeid Nooshabadi,Univ. of New South Wales (Australia); AdamOsseiran, Edith Cowan Univ. (Australia);Dimitris Pavlidis, Univ. of Michigan (USA);Braden Phillips, The Univ. of Adelaide(Australia); Jugdutt J. Singh, Victoria Univ.(Australia); David V. Thiel, Griffith Univ.(Australia)

IntroductionThis multidisciplinary conference covers a wide scopeof topical smart structures, devices, and systemsissues. The conference will bring together university,industry, and government researchers to discuss thepresent state of present, emergent, and futuredirections in the area of microelectronics. Withadvancement in science, increasing interest in theinterfaces between advanced technologies, biologicaland quantum domains become intensified. Thisinterface will be encouraged in all the five parallelconferences in this symposium.

Scope• processors• actuators• sensors and sensor networks• biomimetic devices• piezoelectric microactuators• VLSI• sensors• detectors• displays• molecular and quantum technology• quantum computation technology• optoelectronics• A/D conversion• CMOS device physics• novel MOS device designs• interconnects and interconnect design issues• reconfigurable chip design• SoC• mixed digital/analog designs• mixed analog/RF design• circuits for wireless technology• SOI• SiGe devices• GaN and compound semiconductor devices• reliability• imaging and optics• optics and lasers• optical interconnects• terahertz technology• MEMS and electronics integration• smart electronics• broadband• image processing• signal processing and multiplexing• photonic processing• analytical/numerical simulation and modelling• interface electronics• system level integration• integrated RF components• lower power circuit & system design• device measurement and characterization• tools & methodologies for design & test• system level verification.

Submit your abstract online:

spie.org/events/aucall

IMPORTANT DATES!Abstract Due Date: 5 June 2006

Abstracts, if accepted, will be printed in a booklet anddistributed at the meeting.

Submissions imply the intent of at least one author to register,attend the symposium, present the paper as scheduled (eitherorally or in poster format), and submit a full length manuscriptfor publication in the conference Proceedings.

Manuscript Due Date: Week of 8 September 2006Manuscripts will be peer reviewed, and accepted papers willbe published after the symposium in the Proceedings of SPIE.Condition for publication is that the author must register andpresent their paper at the symposium as scheduled.


Call for Papers

Nano- and Microtechnology:Materials, Processes, Packaging,and Systems III (AU103)Conference Chair: Jung-Chih Chiao, The Univ.of Texas at Arlington (USA)Cochairs: Andrew S. Dzurak, Univ. of NewSouth Wales (Australia); ChennupatiJagadish, The Australian National Univ.(Australia); David V. Thiel, Griffith Univ.(Australia)Program Committee: Derek Abbott, The Univ.of Adelaide (Australia); Richard J. Blaikie,Univ. of Canterbury (New Zealand); Simon A.Brown, Univ. of Canterbury (New Zealand);Carles Cané, Ctr. Nacional deMicroelectrónica (Spain); Mu Chiao, The Univ.of British Columbia (Canada); Franck A.Chollet, Nanyang Technological Univ.(Singapore); Nicolaas F. de Rooij, Univ. deNeuchâtel (Switzerland); John M. Dell, TheUniv. of Western Australia (Australia); RobertG. Elliman, The Australian National Univ.(Australia); Masayoshi Esashi, Tohoku Univ.(Japan); Lorenzo Faraone, The Univ. ofWestern Australia (Australia); Paul D. Franzon,North Carolina State Univ. (USA); ThomasGeorge, ViaLogy Corp. (USA); Katia M.Grenier, LAAS-CNRS (France); Alex R.Hamilton, Univ. of New South Wales(Australia); Kazuhiro Hane, Tohoku Univ.(Japan); Alex J. Hariz, Univ. of South Australia(Australia); Erol C. Harvey, Swinburne Univ. ofTechnology (Australia); Huey Hoon Hng,Nanyang Technological Univ. (Singapore);Ciprian I. Iliescu, Institute of Bioengineeringand Nanotechnology (Singapore); David N.Jamieson, The Univ. of Melbourne (Australia);Chantal G. Khan-Malek, Ctr. National de laRecherche Scientifique (France); Yong-HyupKim, Seoul National Univ. (South Korea);Youngwoo Kwon, Seoul National Univ. (SouthKorea); Ronald A. Lawes, Imperial CollegeLondon (United Kingdom); Woo Ho Lee, TheUniv. of Texas at Arlington (USA); Lih-YuanLin, Univ. of Washington (USA); Liwei Lin,Univ. of California/Berkeley (USA); Victor M.Lubecke, Univ. of Hawai’i at Manoa (USA);Barry Luther-Davies, The Australian NationalUniv. (Australia); Robert M. Mehalso, MicrotecAssociates (USA); Meyya Meyyappan, NASAAmes Research Ctr. (USA); Giacinta Parish,The Univ. of Western Australia (Australia);Steven D. Prawer, The Univ. of Melbourne(Australia); Olaf Reinhold, Defence Scienceand Technology Organisation (Australia); OliviaM. Samardzic, Defence Science andTechnology Organisation (Australia); KazuoSato, Nagoya Univ. (Japan); Michael S. Shur,Rensselaer Polytechnic Institute (USA); Yu-Chuan Su, National Tsing Hua Univ. (Taiwan);Hitoshi Tabata, Osaka Univ. (Japan); HarkHoe Tan, The Australian National Univ.(Australia); Ooi-Kiang Tan, NanyangTechnological Univ. (Singapore); KazuyoshiTsuchiya, Tokai Univ. (Japan); Sai Peng Wong,The Chinese Univ. of Hong Kong (Hong KongChina)

IntroductionAs technologies progress, challenges abound asMEMS, photonic, microelectronic, nanoelectronic, andquantum devices push the boundaries of currentprocessing technologies. This includes adaptingcurrent processing technology, and developing newmaterials, structures, and techniques. MEMS andNEMS, in particular, bring together researchers frommultidisciplinary backgrounds and builds on thefabrication and manufacturing technologies that havebeen developed by the VLSI and precision engineeringindustries. This conference is intended to bringtogether the process developers and integrators,device researchers, and manufacturing engineersinterested in the present and future state of electronic,photonic, quantum, and MEMS device processingtechnologies. The topics covered in the conferencewill be novel processes, process integration of MEMS,ICs, sensors and photonic components, newapplications of existing processing technologies -particularly to new commercial products, andmanufacturing-driven process development.

Scope• Nano and Micro Technologies: quantum computer

technologies, self assembly and organizingtechniques, nanoelectromechanical systems(NEMS), spintronics, echatronics, quantumelectromechanical systems (QEMS), advancedsynchrotron mediated processes, terahertzfrequency, and millimeterwave/submillimeterwavetechnologies.

• Materials: semiconductor materials, ceramics,polymers, electroformed materials, piezoelectricmaterials, photonic bandgap materials,nanotubes, nanowires, nanoparticles, smartmaterials, novel materials and material issues.

• Processes: atomic force microscopy (AFM),process metrology, dicing and assembly methods,packaging processes, processing effects on yieldand reliability, yield management andenhancement, wafer bonding, laser machining,high-aspect ratio microfabrication technologies,photolithography, microstereolithography and newetching/deposition techniques.

• Devices: device architectures, micro/nanoscaledevices, MOEMS, RF MEMS, BioMEMS, fluidics,self-assembly devices, microinstruments,chemical/biomedical analysis microsystems,sensors and actuators.

• Compatibility: integrated packaging, hybrid andintegrated systems, process integration betweenMEMS and ICs, planarization, materialscompatibility, biocompatibility, bulk and surfacemicromachining integration, electrical andmechanical integration techniques, manufacturingissues, and environmental consideration.

Biomedical Applications of Micro-and Nanoengineering III (AU104)Conference Chair: Dan V. Nicolau, The Univ. ofLiverpool (United Kingdom)Cochair: Joe G. Shapter, Flinders Univ.(Australia)Program Committee: Derek Abbott, The Univ.of Adelaide (Australia); Maan M. Alkaisi, Univ.of Canterbury (New Zealand); John M. Bell,Queensland Univ. of Technology (Australia);Shin-Ho Chung, The Australian National Univ.(Australia); Paul Dan A. Cristea, Univ.Politehnica Bucharest (Romania); PiotrGrodzinski, National Institutes of Health (USA);Min Gu, Swinburne Univ. of Technology(Australia); Abraham P. Lee, Univ. ofCalifornia/Irvine (USA); Torsten Lehmann,Univ. of New South Wales (Australia); Nigel H.Lovell, Univ. of New South Wales (Australia);Don McNaughton, Monash Univ. (Australia);Gottfried Otting, The Australian National Univ.(Australia); Tamath J. Rainsford, The Univ. ofAdelaide (Australia); Takahisa Taguchi,National Institute of Advanced IndustrialScience and Technology (Japan)

IntroductionThe scope of the conference focuses on theapplication of engineering-oriented theory, design,fabrication, operation, and applications of micro- andnano-devices to biomedical relevant problems. Thesubjects covered include, but are not limited to:• bioMEMS and bioNEMS• micro/nano-fluidics and lab-on-a-chip devices• biochips and micro/nano-arrays, biosensors,

bioactuators and drug delivery devices,biomedical devices, e.g., cochlear, visual devices

• micro- and nano-manipulation e.g., Atomic ForceMicroscopy, optical tweezers and molecular motordevices

• biotelemetry and telemedicine• bioinspired systems.

Fundamental contributions are also invited in theareas of:• bio-photonic interface• molecular electronics and photonics• nanostructured surfaces and materials• fluctuational phenomena in biosystems• biomolecular interactions with nanostructures• polymer and protein dynamics• quantum states in biomolecules• ion channels, abio-bio interfaces and biomaterials• scaling in biology; bio-info-nano-systems (BINS)• modelling and simulation of complex networks• cellular dynamics• biospectroscopy• biophotonics• biomimetic systems• bioinformatics• biomaterials.


Call For Papers

Complexity and NonlinearDynamics (AU105)Conference Chair: Axel Bender, DefenceScience and Technology Organisation(Australia)Cochair: Derek Abbott, The Univ. of Adelaide(Australia)

Introduction

Most natural systems are “on the edge of chaos” -between order and randomness. Complexity, asgoverned by non-linear dynamics, can be observedeverywhere. It therefore comes as no surprise thatmany scientific and engineering disciplines deal withcomplex system phenomena and characteristics suchas self-organization, emergence, adaptation, non-linear feed-forward and feedback, stochasticresonance or swarm and herd behaviours. Bothunderstanding and taking advantage of complexityand the underlying nonlinear dynamic processes aretwo of the biggest challenges of scientists andengineers today.

This conference will provide a forum for university,industry, and government researchers from a multitudeof disciplines to exchange ideas, communicate recentscience and technology developments, and discusspresent, emergent and future directions in researchareas pertaining to complexity and non-lineardynamics.

Scope

The conference invites contributions from the followingbroad areas of research:• complexity theory• complex mechanisms• complex simulations• complex behaviour• self-organizing processes• complex system engineering• emergence, cooperation, adaptation.

Topics include, but are not limited to:• bifurcation theory, chaos theory• fractals and scaling systems• synchronization and self-synchronization• nonlinear feed-forward and feedback• collective behavior, competition for limited

resources• multi-scale dynamics• reduced dynamical systems• thermo-kinetic instabilities• far-from-equilibrium systems• correlated disorder• real-world networks, small world networks,

network theory and analysis• cellular automata• agent-based modelling, multi-agent systems• evolutionary computation, artificial life, genetic

algorithms• social complexity, computational sociology• neurodynamics and neuroeconomics• self-assembly• complex and hierarchical materials.• swarm intelligence and behaviour• biological control systems.

Submit your abstract online:


IMPORTANT DATES!Abstract Due Date: 5 June 2006

Abstracts, if accepted, will be printed in a booklet anddistributed at the meeting.

Submissions imply the intent of at least one author to register,attend the symposium, present the paper as scheduled (eitherorally or in poster format), and submit a full length manuscriptfor publication in the conference Proceedings.

Manuscript Due Date: Week of 8 September 2006Manuscripts will be peer reviewed, and accepted papers willbe published after the symposium in the Proceedings of SPIE.Condition for publication is that the author must register andpresent their paper at the symposium as scheduled.


General Information

Join us in Adelaide!Adelaide is the capital of the Festival State. It isa city of one million plus people situated on theAdelaide plains, a flat, fertile corridor of landbetween Gulf St Vincent and the arc of the MountLofty Ranges. The city is surrounded byparklands, sports fields, a top-class golf course,walking and cycling tracks, and beautifulgardens. The University of Adelaide, the heart ofthe city, is surrounded by green parklands withthe River Torrens passing through the center.Plan to stay a few extra days to experience thesights and sounds that abound in Adelaide!

Technical ProgramAvailable September 2006The comprehensive Advance Technical Programfor this symposium will list conferences, papertitles, and authors in order of presentation; anoutline of all planned special events; and hoteland registration information. All those who submitan abstract will receive a copy.

Registration FeeAll participants, including invited speakers,contributed speakers, session chairs, cochairs,and committee members must pay a registrationfee. Fee information will be available in theTechnical Program distributed in September.

Student Travel Contingency GrantsA limited number of student travel contingencygrants will be awarded based on need. Grantapplications can be found at http://www.spie.org/CommunityServices/StudentsAndEducators/under the Scholarships & Grants section in theleft menu. Applications must be received no laterthan 10 weeks prior to the meeting. Eligibleapplicants must present an accepted paper atthis meeting.

Clearance InformationIf government and/or company clearance isrequired to present and publish yourpresentation, start the process now to ensure thatyou receive clearance if your paper is accepted.

Visa InformationParticipants of an event or conference in Australiawill generally need to apply for a subclass 456Business (Short Stay) Visitor visa. Furtherinformation is available on the department website:

http://www.immi.gov.au

If an overseas participant is eligible to obtain anElectronic Travel Authority (ETA) they may applyfor either a Short or Long Validity Business VisitorETA.

Additional information on the Department ofImmigration and Multicultural and IndigenousAffairs’ Electronic Travel Authority system can befound via the following links.

See: www.immi.gov.au/eta/

An ETA is issued within seconds by computerlinks between the Department of Immigration andMulticultural Affairs (DIMA), travel agents, airlinesand specialist service providers around the worldand the Internet.

No evidence of the ETA is needed, as it iselectronically stored in the system. Airlines andtravel agents participating in the ETA system canconfirm its existence on behalf of travelers.

Letters of Invitation for VisaProcessIndividuals requiring letters of invitation to obtaintravel visas to present their papers may accessand print an Invitation Letter Request Form foundat http://spie.org/forms/invitationrequest.pdf

Please fill out a separate form for each personrequesting a letter. All letters of invitation will besent by airmail from Australia and by PDF e-mailattachment unless a courier account number orcredit card number with expiration date isprovided with the original request. Please allowample time for processing requests. SPIE is notable to contact embassies in support of anindividual attempting to gain entry to attend anSPIE meeting. Because the application for a visacan be a lengthy process, we recommend thatyou begin your visa application process as soonas you have been notified that your abstract hasbeen accepted for presentation. We alsorecommend that you secure your travel visabefore registering for the symposium.Cancellations after the preregistration cutoff canresult in a cancellation fee.


Call For Papers

IMPORTANT!

Submissions imply the intent of at least one author to register, attendthe symposium, present the paper (either orally or in poster format),and submit a full-length manuscript for publication in the conferenceProceedings.

All authors (including invited or solicited speakers), program committeemembers, and session chairs are responsible for registering and paying thereduced author, session chair, program committee registration fee. (CurrentSPIE Members receive a discount on the registration fee.)

Instructions for Submitting Abstracts via Web

You are STRONGLY ENCOURAGED to submit abstracts using the “sub-mit an abstract” link at:


Submitting directly on the Web ensures that your abstract will be immedi-ately accessible by the conference chair for review through MySPIE, SPIE’sauthor/chair web site.

Please note! When submitting your abstract you must provide contact in-formation for all authors, summarize your paper, and identify the contactauthor who will receive correspondence about the submission and whomust submit the manuscript and all revisions. Please have this informationavailable before you begin the submission process.

First-time users of MySPIE can create a new account by clicking on thecreate new account link. You can simplify account creation by using yourSPIE ID# which is found on SPIE membership cards or the label of any SPIEmailing.

If you do not have web access, you may E-MAIL each abstract separatelyto: [email protected] in ASCII text (not encoded) format. There will be atime delay for abstracts submitted via e-mail as they will not be immediatelyprocessed for chair review.

IMPORTANT! To ensure proper processing of your abstract, the SUBJECTline must include only:

SUBJECT: Conf. Code (AU06)

Your abstract submission must include all of the following:

1. PAPER TITLE

2. AUTHORS (principal author first) For each author: First (given) name(initials not acceptable), Last (family) name, Affiliation, Mailing address,Telephone, Fax, and Email address.

3. PRESENTATION PREFERENCE “Oral Presentation” or “PosterPresentation.”

4. PRINCIPAL AUTHOR’S BIOGRAPHY Approximately 50 words.

5. ABSTRACT TEXT Approximately 250 words.Accepted abstracts for this conference will be included in the abstractdigest CD-ROM which will be available at the meeting. Please submitonly 250-word abstracts that are suitable for publication.

6. KEYWORDS Maximum of five keywords.

Submission of Abstracts

Abstract Due Date: 5 June 2006

Manuscript Due Date: Week of 18 September 2006

Conditions of Acceptance• Authors are expected to secure funding for registration fees, travel, and

accommodations, independent of SPIE, through their sponsoring orga-nizations before submitting abstracts.

• Only original material should be submitted.• Commercial papers, papers with no new research/development content,

and papers where supporting data or a technical description cannot begiven for proprietary reasons will not be accepted for presentation in thissymposium.

• Abstracts should contain enough detail to clearly convey the approachand the results of the research.

• Government and company clearance to present and publish should befinal at the time of submittal. If you are a DoD contractor, allow at least 60days for clearance. Authors are required to warrant to SPIE in advance ofpublication of the Proceedings that all necessary permissions and clear-ances have been obtained, and that submitting authors are authorized totransfer copyright of the paper to SPIE.

Review, Notification, Program Placement• To ensure a high-quality conference, all abstracts and Proceedings manu-

scripts will be reviewed by the Conference Chair/Editor for technical meritand suitability of content. Conference Chair/Editors may require manu-script revision before approving publication, and reserve the right to re-ject for presentation or publication any paper that does not meet contentor presentation expectations. SPIE’s decision on whether to accept apresentation or publish a manuscript is final.

• Applicants will be notified of abstract acceptance by mail no later than 31July 2006. Early notification of acceptance will be sent by e-mail duringthe week of 4 September 2006.

• Final placement in an oral or poster session is subject to the Chairs’ dis-cretion. Instructions for oral and poster presentations will be sent to youby email. All oral and poster presentations require presentation at themeeting and submission of a manuscript to be included in the Proceed-ings of SPIE.

Proceedings of SPIE and SPIE Digital Library• These conferences will result in full-manuscript Chairs/Editor-reviewed

volumes published in the Proceedings of SPIE and in the SPIE DigitalLibrary.

• Correctly formatted, ready-to-print manuscripts submitted in English arerequired for all accepted oral and poster presentations. Electronic sub-missions are recommended, and result in higher quality reproduction.Submission must be provided in PostScript created with a printer drivercompatible with SPIE’s online Electronic Manuscript Submission system.Instructions are included in the author kit and from the “Author Info” linkat the conference website.

• Authors are required to transfer copyright of the manuscript to SPIE or toprovide a suitable publication license.

• Papers published are indexed in leading scientific databases includingINSPEC, Ei Compendex, Chemical Abstracts, International AerospaceAbstracts, Index to Scientific and Technical Proceedings and NASA As-trophysical Data System, and are searchable in SPIE’s Digital Library. Fullmanuscripts are available to Digital Library subscribers.

• Late manuscripts may not be published in the conference Proceed-ings and SPIE Digial Library, whether the conference volume will bepublished before or after the meeting. The objective of this policy is tobetter serve the conference participants as well as the technical commu-nity at large, by enabling timely publication of the Proceedings.

• Papers not presented at the meeting will not be published in theconference Proceedings, except in the case of exceptional circum-stances at the discretion of SPIE and the Conference Chairs/Editors.

Smart Materials, Nano-and Micro-Smart Systems

P.O. Box 10Bellingham, WA 98227-0010 USA

Non-Profit Org.U.S. Postage Paid

Society ofPhoto-Optical

InstrumentationEngineers


Call For Papers

• Publish your work

• Hear the latest research

• Network with your peers

Submit your abstract online!


Symposium Chairs:Joe G. Shapter, Flinders Univ. of South Australia

(Australia)Vijay K. Varadan, Univ. of Arkansas (USA)Derek Abbott, Univ. of Adelaide (Australia)

smart materials, nano- and micro-smart systems• mixed analog/rf design • circuits for wireless...

Documents