FY 2000 ITL Publications
Note that some documents are published in more than one place. Due to the large number of documents, publications listed in previous ITL Technical Accomplishment reports are not repeated.
Nakassis, A., Carasso, A. S.; Image Compression and Deblurring; NISTIR 6521; 5/31/2000
What follows is the description of an experiment in which we investigated the possibility that blurring techniques and lossless compression could be combined as an alternative to lossy compression techniques for still images. Our results show that while blurred images compress losslessly better than their originals, this technique offers relatively modest compression ratios which can be matched by lossily compressed images (JPEG) having less noticeable artifacts.
Nechvatal, J.O., Barker, E.B., Bassham, L.E., Burr, W., Dworkin, M.O., Foti, J.G., Roback, E.A.; Report on the Development of the Advanced Encryption Standard (AES); NIST Journal of Research
In 1997, the National Institute of Standards and Technology (NIST) initiated a process to select a symmetric-key encryption algorithm to be used to protect sensitive (unclassified) federal information in furtherance of NIST's statutory responsibilities. In 1998, NIST announced the acceptance of fifteen candidate algorithms and requested the assistance of the cryptographic research community in analyzing the candidates. This analysis included an initial examination of the security and efficiency characteristics for each algorithm. NIST reviewed the results of this preliminary research and selected MARS, RC6T, Rijndael, Serpent and Twofish as finalists. Having reviewed further public analysis of the finalists, NIST has made a selection, which will be proposed for inclusion in the Advanced Encryption Standard (AES). The research results and rationale for this selection are documented in this report.
O'Hern, C.S., Langer, S.A., Liu, A.J., Nagel, S.R.; Force Distributions Near the Jamming and Glass Transitions; Submitted to Physical Review Letters
We measure the distributions of interparticle normal forces P(F) near the glass transition in supercooled liquids and near the jamming transition in foams and compare them to those obtained in recent experiments on static granular packings. We find that the distributions P(F) for glasses, jammed foams, and static granular packings are very similar, showing a plateau or small peak at small forces. We propose that the formation of this peak signals the development of a yield stress in glasses and jammed systems.
Over, P.D.; The TREC Interactive Track: An Annotated Bibliography; Information Processing and Management
The study of interactive information retrieval (IR) has been a small but constant part of Text Retrieval Conferences (TREC 1-8) from the beginning. The main arena for such work has been the Interactive Track (TREC 3-8). This report presents a bibliography of such efforts together with a summary of the evolving experimental framework within which the studies took place.
Podio, F. L., Dunn, J. S.; A Biometric Application Programming Interface Industry Standard - Benefits for the Users and the Enterprise; NISTIR and Proceedings of CardTech/SecurTech 2000 Conference
This paper defines biometrics technologies and states that these technologies are ideally suited to provide highly secure identification and personal
verification solutions. The benefit of biometric standards to the end-users, the Enterprise and the global economy is discussed as well as how biometric
industry standards will affect identification and verification security applications. The evolution and emergence of Biometric Application Programming
Interfaces is addressed with special emphasis on the BioAPI Consortium and BioAPI's specification. NIST's research efforts in biometric interoperability
and NIST's BioAPI test bed is described.
Potman, J.; eBook Standards; NISTIR and Proceedings of NIST Electronic 2000 Conference
A discussion of current and proposed eBook standards and their applications. The discussions include: Open eBook Publication Structure (OEBPS), Portable Document Format (PDF), Open eBook File Format (OEBFF), Electronic Book Exchange System (EBX), Extensible rights Markup language (XrML) and ONIX International.
Presser, C., Widmann, J. F., Leigh, S. D.; Effect of Burst-Splitting Events on Phase Doppler Interferometry Measurements; Submitted to AIAA Aerospace Sciences Meeting and Exhibit
Burst splitting events, in which noisy environments result in a single droplet being counted as multiple droplets by the processor during phase Doppler interferometry (PDI) measurements, are investigated. The cause of burst splitting is discussed and compared with chattering, another phenomena that results in over-counting of droplets in PDI measurements. Several techniques are presented to identify the occurrence of burst splitting events, and the impact of the events on the measurements is discussed. It is shown that burst splitting has a serious effect on the volume flux measurements. The impact on the size and velocity distributions is much weaker; however, the events significantly distort the probe volume correction, which is applied to the measured distributions to remove the bias introduced by the size dependence of the probe area. Judicious choice of operating parameters can minimize the impact of burst splitting occurrences.
Ranganathan, M., Bednarek, Marc, Montgomery, Doug; A Reliable Message Delivery Protocol for Mobile Agents; Agent Systems and Architectures / Mobile Agents (ASA/MA) 2000, Zurich, Switzerland, September 3-6, 2000, 6/3/2000
The abstractions and protocol mechanisms that form the basis for inter-agent communications can significantly impact the overall design and effectiveness of Mobile Agent systems. We present the design and performance analysis of a reliable communication mechanism for Mobile Agent systems. Our protocols are presented in the context of a Mobile Agent system called AGNI. We have developed AGNI communication mechanisms that offer reliable peer-to-peer communications, and that are integrated with our agent location tracking infrastructure to enable efficient, failure-resistant networking among highly mobile systems. We have analyzed the design parameters of our protocols using an in-situ simulation approach with validation through measurement of our prototype implementation in real distributed systems. Our system assumptions are simple and general enough to make our results applicable to other Agent systems that may adopt our protocols and/or design principles.
Roback, E.A.; NIST Division Launches Programs for Testing Product Security; Government Computer News; 6/12/2000
Federal organizations need to have an appropriate level of confidence that the security features of IT products work as intended and meet security specifications. The basis for having such confidence is through security assurance. Products with an appropriate degree of assurance contribute to the security and assurance of the system as a whole and thus should be an important factor in IT procurement decisions. NIST helps agencies obtain security assurance in products through two programs for product evaluation and testing -- the National Information Assurance Partnership (NIAP)'s Common Criteria Evaluation and Validation Scheme and the Cryptographic Module Validation Program (CMVP). Both programs use accredited private sector laboratories to conduct the actual testing and issue government certificates upon successful completion of testing. The NIAP's evaluation program focuses on evaluations of against a set of security specifications drawn from the "Common Criteria" (ISO 15408). Testing under CMVP helps provide customers with assurance that: 1) a cryptographic module meets one of the four security specification levels of Federal Information Processing Standard (FIPS) 140-1, Security
Requirements for Cryptographic Modules and 2) that the FIPS-approved algorithms (e.g., for encryption or digital signatures) are correctly implemented. Both programs help agencies have confidence in the security aspects of the IT products they use.
Roback, E.A.; Guidelines to Federal Organizations on Security Assurance and Acquisition/Use of Tested/Evaluated Products -- Recommendations of the National Institute of Standards and Technology; NIST SP 800-23; 8/28/2000
Computer security assurance provides a basis for one to have confidence that security measures, both technical and operational, work as intended. Use of products with an appropriate degree of assurance contributes to security and assurance of the system as a whole and thus should be an important factor in IT procurement decisions. Two Government programs are of particular interest -- the National Information Assurance Partnership (NIAP)'s Common Criteria
Evaluation and Validation Program and NIST's Cryptographic Module Validation Program (CMVP). The NIAP program focuses on evaluations of products (e.g., a firewall or operating system) against a set of security specifications. The CMVP program focuses on security conformance testing of a cryptographic module against Federal Information Processing Standard 140-1, Security Requirements for Cryptographic Modules and related federal cryptographic algorithm standards.
Roberts, J.W., McCrary, V.R. (editor); Rotating-Wheel Braille Display Provides Low-Cost Accessibility to Electronic Books; Proceedings of NIST Electronic Book 2000 Conference
We have developed a new technology to reduce the cost of Braille-based information accessibility. Millions of blind and visually impaired people in the U.S. (and far higher numbers worldwide) need some form of non-visual access to information. The widespread use of Braille displays has been limited primarily by cost and reliability issues. The primary cost and reliability factor is the large number of electromechanical actuators. Each 6/8-dot Braille cell requires 6/8 actuators, with hundreds needed for the entire display. Small displays (e.g., 8-character) are available, but require the user to move a finger back and forth, raising issues of convenience and repetitive stress injuries. Our approach uses as few as 3 to 4 actuators for the entire display. Our objective in undertaking this project was to find a new approach to Braille display design that would significantly lower cost and improve reliability, and still provide a worthwhile reading experience approaching that of full-line (80-character) displays. Our target was a factor of ten reduction in display cost. After receiving comments from Braille users regarding our first-generation prototype (announced in September 1999), we have developed a second-generation design, with major design changes, and with significant performance and usability improvements.
Roberts, J.W., Slattery, O.T.; Display Characteristics and the Impact on Usability for Stereo; SPIE proceedings series
Over the past decade, the number of electronic display technologies available to consumers has risen dramatically, and the capabilities of existing technologies have expanded. This proliferation of choices provides new opportunities for visual stereo presentation, but also new challenges. The methods of implementing stereo on an electronic display, optimized for the original capabilities of the original displays, may no longer be the best choices. Features such as response time, frame rate, aspect ratio, sync timing, pixel registration, and temporal modulation of grayscale (brightness) and color can strongly influence the process of selecting an optimum presentation format for a given display technology. Display performance issues such as brightness, contrast, flicker, image distortion, defective pixels, and mura are more critical in 3D imagery than in 2D. Susceptibility to burn-in limits the implementation choices for a display that is to be used for both 3D and 2D applications. Resolution and frame rate establish the overall capability for representing depth, and also establish the performance requirements for the engine providing the 3D material.
This paper surveys the capabilities and characteristics of traditional displays such as CRT and LCD panel, and a broad assortment of newer display technologies, including color plasma, field emission, micromirror and other reflective systems, and the general classes of microdisplays. Relevance of display characteristics to various stereo presentation formats is discussed, with description of laboratory experimentation to provide hard numbers. Recommendations are made regarding the stereo formats to be used with various display technologies, and the display technologies to be used with various stereo formats.
Roberts, J.W., Slattery, O.T., Kardos, D.W.; Rotating-Wheel Braille Display for Continuous Refreshable Braille; Proceedings, Society for Information Display, SID '00 Conference
The increasingly pervasive influence of information technology on daily life makes accessibility a higher priority than ever before. Millions of blind and visually impaired people in the U.S. (and far higher numbers worldwide) need some form of non-visual access to information. Non-visual displays differ from visual displays, but some features and issues are strikingly similar to those of visual displays. Significant progress has been made with text-to-speech systems, but many users prefer the precision and the reading experience of touch-based Braille systems. The widespread use of Braille displays has been limited primarily by cost and reliability issues. The cost to the user of a conventional 80-character Braille display is often $10000-15000 U.S., and maintenance costs can be around $500 per year. The primary cost and reliability factor is the large number of electromechanical actuators. Each 6- or 8-dot Braille cell requires six or eight actuators, with hundreds needed for the entire display. Smaller displays (e.g., 8-character) are available, but require the user to move a finger back and forth, raising issues of convenience and repetitive stress injuries. Our objective in undertaking this project was to find a new approach to Braille display design that would significantly lower cost and improve reliability, and still provide a worthwhile reading experience approaching that of full-line (80-character) displays. Our target was a factor of ten reduction in display cost.
Roberts, J.W., Slattery, O.T., Kardos, D.W., Swope, B.M.; New Technology Enables Many-Fold Reduction in the Cost of Refreshable Braille Displays; Proceedings, ASSETS 2000 - ACM SIGCAPH Conference on Assistive Technologies
By analysis of the primary cost factors for existing refreshable Braille displays, a team at NIST has pioneered a new technology that can reduce the cost of the electromechanical portions of a Braille display by an extremely large factor, and the overall cost of a Braille display by as much as a factor of ten. A massive cost reduction in displays creates a new model for the purchase and use of Braille displays by individuals, by employers, and by educators. Readability and user control issues are addressed. It is hoped that this technology will open a significant new market for low-cost, high-performance refreshable Braille displays.
Rosenthal, L., Skall, M.; Software Validation; Encyclopedia of Software Engineering (Wiley publication)
Software validation is the process of testing software for compliance with applicable specifications or standards. Validation testing is accomplished by using an official test suite in a prescribed manner. This article discusses the components that comprise validation testing, (i.e., a standard, a conformance test suite, a testing laboratory, a certification authority, a control board, and testing procedure) as well as the testing process. Examples of how different organizations have implemented the validation components and test process is also given.
Rosenthal, L., Stanford, V.; NIST Information Technology Laboratory Pervasive Computing Initiative; Proceedings of IEEE 2000 WETICE 2000 -- IEEE Ninth International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises
The next great computing paradigm shift, to pervasive computing, is already well under way and will have no less of an impact on industry, government, and daily life than the personal computing revolution. Pervasive computing refers to the emerging trend toward numerous, easily accessible computing devices connected to each other and to an increasingly ubiquitous network infrastructure. This trend will likely create new opportunities and challenges for Information Technology (IT) companies to place computers and sensors in virtually every device, appliance, and piece of equipment in buildings, homes, workplaces, factories, and even clothing. Within five years vendors will offer portable and embedded devices containing low-cost systems-on-a-chip (SOC) with enough CPU, memory, and input/output logic to execute complex software applications, and use pico-cellular wireless communications. Effective pervasive computing must present user interfaces distributed across numerous, often small, and even invisible devices. This requires new techniques in measurement, software testing, management of the frequency space, and human-computer interactions. Failure to develop and exploit these pervasive computing technologies and techniques may be very costly to U.S. IT companies.
Rukhin, A., Soto, J., Nechvatal, J., Smid, M., Barker, E., Leigh, S., Levenson, M., Vangel, M., Banks, D., Heckert, A., Dray, J., Vo, S.; A Statistical Test Suite for Random and Pseudorandom Number Generators for Cryptographic Applications; NIST SP 800-22; 10/31/2000
This paper discusses some aspects of selecting and testing random and pseudorandom number generators. The outputs of such generators may be used in many cryptographic applications, such as the generation of key material. Generators suitable for use in cryptographic applications may need to meet stronger requirements than for other applications. In particular, their outputs must be unpredictable in the absence of knowledge of the inputs. Some criteria for characterizing and selecting appropriate generators are discussed in this document. The subject of statistical testing and its relation to cryptanalysis is also discussed, and some recommended statistical tests are provided. These tests may be useful as a first step in determining whether or not a generator is suitable for a particular cryptographic application. However, no set of statistical tests can absolutely certify a generator as appropriate for usage in a particular application, i.e., statistical testing cannot serve as a substitute for cryptanalysis. The design and cryptanalysis of generators is outside the scope of this paper.
Russakoff, D., Herman, M.; Head Tracking Using Stereo; Workshop on the Application of Computer Vision, Palm Springs, California, December 4-6, 2000
Head tracking is an important primitive for smart environments and perceptual user interfaces where the poses and movements of body parts need to be determined. Most previous solutions to this problem are based on intensity images and, as a result, suffer from a host of problems including sensitivity to background clutter and lighting variations. Our approach avoids these pitfalls by using stereo depth data together with a simple human torso model to create a head tracking system that is both fast and robust. We use stereo data to derive a depth model of the background, which is then employed to provide accurate foreground segmentation. We then use directed local edge detectors on the foreground to find occluding edges which are used as features to fit to a torso model. Once we have the model parameters, the location and orientation of the head can be easily estimated. A useful side effect from using stereo data is the ability to track head movement through a room in three dimensions. Experimental results on real image sequences are given.
Russek, S.E., Kaka, S., Donahue, M.J.; High-Speed Dynamics, Damping, and Relaxation Times in Submicrometer Spin-Valve Devices; Journal of Applied Physics 87 (2000), pp. 7070-7072
Rust, B.W.; Parameter Selection for Constrained Solutions to Ill-Posed Problems; Computing Science and Statistics, Volume 33, Proceedings of the Interface 2000 Conference
Many physical measurements are modeled by linear integral equations expressing each measurement as the sum of an instrumental smearing of the desired function and a random measuring error. Discretizing the integrals gives an ill-conditioned linear regression model with a matrix whose columns are discrete response functions of the instrument. Linear least squares solutions give wildly oscillating, physically impossible estimates of the function being measured. Such estimates are often stabilized either by truncating the singular value decomposition of the response matrix or by introducing a regularization constraint on the solution vector, In the former case it is necessary to choose a "numerical rank" for the matrix, and in the latter case to choose the value of the Lagrange multiplier in the constrained minimization. This paper suggests methods for using the statistical properties of the measuring errors and the residuals in making those choices.
Saunders, B., Wang, Q.; Using Numerical Grid Generation to Facilitate 3D Visualization of Complicated Mathematical Functions; NISTIR 6413; 11/30/1999
Although virtually unchanged since its initial publication in 1964, the National Bureau of Standards (NBS) Handbook of Mathematical Functions continues to be widely used by the mathematical and scientific community. As a result, the National Institute of Standards and Technology (NIST), the successor organization to NBS, is engaged in a large scale project to update and expand the handbook and disseminate it on the World Wide Web as the NIST Digital
Library of Mathematical Functions (DLMF). A key feature of the DLMF will be 3D graphics and visualization capabilities that allow a user to interactively examine the unique features of complicated mathematical functions. The authors have discovered that many commercial packages produce adequate surface plots of functions, but improperly clip the surface when the plot must be rescaled to emphasize interesting features. This paper discusses some initial results in using a "contour" fitted mesh to generate an appropriately clipped surface plot and examines some of the issues involved in extending the technique to more complicated surfaces.
Saunders, B., Wang, Q.; From 2D to 3D: Numerical Grid Generation and the Visualization of Complex Surfaces; NISTIR 6555 and Proceedings of the 7th International Conference on Numerical Grid Generation in Computational Field Simulations, Whistler, British Columbia, Canada, September 25-28, 2000; 8/1/2000
The widespread use of high level mathematical functions to solve problems in the mathematical and physical sciences has led the National Institute of Standards and Technology to engage in a massive project to update and expand the National Bureau of Standard Handbook of Mathematical Functions [1]. The handbook will be disseminated on the World Wide Web as the NIST Digital Library of Mathematical Functions. A key feature of the digital library will be 3D visualization capabilities that allow a user to interactively examine the unique features of complicated mathematical functions. This paper discusses the use of grid generation techniques to facilitate the plotting of the complicated 3D surfaces that represent these higher mathematical functions.
Scholtz, Jean C.; The IUSR Project: Industry Usability Report; Make It Easy 2000
The Industry Usability Report (IUSR) Project is designed to help potential corporate purchasers of software obtain information about the usability of supplier products. There are two parts to the IUSR project: a proposed format for sharing usability information, and a pilot study which will allow both supplier (the developer of the software) and consumer (the purchaser of the software) companies to test the effectiveness of using usability test results as procurement criteria and to verify the usefulness of the reporting format.
Scholtz, Jean C.; Evaluation Methodologies: A Framework for Collaboration between HCI Research and Practice; SIGCHI Bulletin
AT CHI 2000, a workshop was held on Frameworks for Collaboration between HCI Research and Practice. Attending were HCI researchers, HCI practitioners, and funders of HCI research from different countries. This article contains summaries of the presentations made at the workshop (NOTE: This article is my presentation summary.) and summaries of the four breakout groups at the workshop: 1. Why collaborate between HCI research and practice? 2. Methods and
models for information exchange between HCI research and practice? 3. Who should review / monitor / supervise HCI projects? 4. How to set up a call for proposal / tender for HCI funding?
Scholtz, Jean C.; Adaptation of Traditional Usability Testing Methods for Remote Testing; Hawaii International Conference on System Science
Traditional usability testing methods are difficult to use in producing web sites and web applications mainly because of the decreased development times that companies demand for this type of software. Users of web sites have diverse platforms, computer expertise, and expectations. Companies want to use web sites to sell merchandize and provide service to customers. Therefore, it is essential to make usability a high priority in the development of
web-based software. How can we resolve this seemingly contradictory situation? We believe that usability testing tools that are remote, rapid, and automated will be helpful in providing more usability information in a shorter time and in a form that can be immediately useful to usability professionals. In this paper we discuss the approach we have taken to designing such tools. We currently have several tools available for public use. Our next steps will be to conduct methodological studies to validate the use of these tools.
Scholtz, Jean C.; Common Industry Format for Usability Test Reports; CHI2000 Conference, The Hague, Netherlands, April 1-6, 2000; 4/1/2000
This paper is a proposal for conducting a Special Interest Group (SIG) at the CHI2000 Conference. The focus of the meeting will be the use of the Common Industry Format (CIF) developed by the Industry Usability Reporting (IUSR) project, a group managed by NIST.
Scholtz, Jean C., Mills, Kevin L.; Workshop on Intelligent Environments; IEEE Personal Communications Magazine
In July 1999, three agencies in the US government (the Defense Advanced Research Projects Agency, the National Science Foundation, and the National Institute of Standards and Technology) sponsored a workshop on Smart Spaces. The intention of this workshop was to begin to build a multi-disciplinary consensus about the challenging research problems that must be solved before Ubiquitous Computing environments could be routinely deployed and used by people. This paper contains the summary of the workshop, as well as expanded position papers submitted by selected workshop attendees.
Snelick, R.D., Salamon, W.J., Mink, A.; Implementation of an Interactive Digital TV Java Environment; 4th Annual IASTED International Conference on Software Engineering and Applications (SEA 2000), Las Vegas, Nevada, November 6-9, 2000
The emergence of interactive digital television (DTV) brings about a host of exciting opportunities for broadcasters, content providers, tool developers, and equipment manufacturers. Interactive DTV combines aspects of traditional television and the Internet that inspire applications in e-commerce, targeted advertising, video-on-demand, education and other enhanced viewing services. An enabling technology for applying interactive DTV is being developed by the Advanced Television Systems Committee (ATSC) Digital TV Application Software Environment (DASE) specialist group. This middleware standard environment fosters the interoperability concept of write once, run anywhere applications. An important part in development and deployment of the DASE standard is the existence and availability of an open reference implementation. The National Institute of Standards and Technology (NIST) is constructing this reference implementation. In addition, NIST is building a set-top box (STB) simulation platform for the implementation to run on. Together these components constitute the NIST/DASE reference platform. We present the design, implementation, and use of the NIST/DASE reference platform that provides a software development environment of the DASE standard for designers, implementers, and content providers.
Snouffer, S.R.; FIPS 140-2: The Next Generation (The Cryptographic Module Validation Program); Department of Defense: IA Newsletter
On July 17, 1995, NIST established the Cryptographic Module Validation Program (CMVP) which validates cryptographic modules to Federal Information Processing Standard FIPS 140-1 (Security Requirements for Cryptographic Modules), and other FIPS cryptography based standards. The CMVP is a joint effort between NIST and the Communications Security Establishment (CSE) of the Government of Canada. Products validated as conforming to FIPS 140-1 are accepted by the Federal agencies of both countries for the protection of sensitive information. The NIST's Computer Security Division together with CSE, serve as the validation authorities for the program. In the CMVP, vendors of cryptographic modules use independent, accredited testing laboratories to test their modules. Currently, there are four National Voluntary Laboratory Accreditation Program (NVLAP) accredited laboratories that perform FIPS 140-1 compliance testing; three in the U.S. and one in Canada. Since the inception of the program, the number of validated modules has nearly doubled each year. As of August 2000 over 100 cryptographic modules from more than forty separate vendors have been validated through the program. The standard is officially reexamined and reaffirmed every five years. In the Fall of 1998 FIPS 140-1 entered a regularly scheduled 5-year review to consider new and/or revised requirements needed to meet technological and economic change. A request for comments on FIPS 140-1 was published on October 23, 1998 in the Federal Register. A revised draft standard was produced based on the public comments received, previously issued implementation guidance and a "line by line" review by the NIST, CSE, and testing laboratory staff. A second request for comments on the resulting FIPS 140-2 draft was published on November 17 in the Federal Register. Completion of the FIPS 140-1 update to FIPS 140-2 is anticipated in September. This paper is gives an overview of the substantive differences between FIPS 140-2 and FIPS 140-1.
Soto, J., Bassham, L. E.; Randomness Testing of the Advanced Encryption Standard Finalist Candidates; NISTIR 6483; 4/1/2000
Mars, RC6, Rijndael, Serpent and Twofish were selected as finalists for the Advanced Encryption Standard (AES). To evaluate the finalists' suitability as random number generators, empirical statistical testing is commonly employed. Although it widely believed that these five algorithms are indeed random, randomness testing was conducted to show that there is empirical evidence supporting this belief. In this paper, NIST reports on the studies that were conducted on the finalists for the 192-bit key size and 256-bit key size. The results to date suggest that all five of the finalists appear to be random.
Squyers, J.M., Devaney, J.E., George, W.L., Hagedorn, J.G., Lumsdaine, A.; The Interoperable Message Passing Interface (IMPI) Extensions to LAM/MPI; Proceedings of the MPI Developer's and User's Conference, MPIDC 2000
Interoperable Message Passing Interface (IMPI) is a protocol specification to allow multiple MPI implementations to cooperate on a single MPI job. Unlike portable MPI implementations, an IMPI-connected parallel job allows the use of vendor-tuned message passing libraries on given target architectures, thus potentially allowing higher levels of performance than previously possible. Additionally, the IMPI protocol uses a low number of connections, which may be suitable for parallel computations across WAN (wide area network) distances. The IMPI specification defines a low-level wire protocol when communicating with a remote MPI implementation. When running IMPI jobs, the only change visible to the user is the sequence of steps necessary to run the job; any correct MPI program will run correctly under IMPI. In this paper, we provide an overview of IMPI, describe its incorporation into the LAM (Local Area Multicomputer) implementation of MPI, and show an example of its use.
Sterling, D.G.; Chaotic Synchronization of Coupled Ergodic Maps; Journal/Chaos (AIP)
With few exceptions, studies of chaotic synchronization have focused on dissipative chaos. Though less well known, chaotic systems that lack dissipation may also synchronize. Motivated by an application in communication systems, we couple a family of ergodic maps on the Ntorus and study the global stability of the synchronous state in the coupled system. While most trajectories synchronize at some time, there is a measure zero set that never synchronizes. We give explicit examples of these asynchronous orbits in dimensions two and four. On more typical trajectories, the synchronization error reaches arbitrarily small values, though it may never converge. We show that the invariant manifold corresponding to the synchronous state is not a
topological attractor. Nonetheless, in practice almost every trajectory synchronizes at some time. In dimension two we give bounds on the average synchronization time for the trajectories resulting from randomly chosen initial conditions. Numerical experiments suggest similar bounds exist in higher dimensions as well. AMS classification scheme numbers: ????
Stoneburner, G.R.; CSPP - Guidance for COTS Security Protection Profiles; NISTIR 6462; 12/31/1999
CSPP provides the guidance necessary to develop "compliant," Common Criteria protection profiles for near-term achievable, security baselines using commercial off-the-shelf (COTS) information technology. CSPP accomplishes this purpose by describing a largely policy-neutral, notional information system in the format of a protection profile (PP), specifying a subset of the common criteria to be used in developing "compliant" protection profiles, and providing the basis for refining policy neutral guidance into specific policy requirements and system security threats, objectives, and requirements into a subset which is appropriate for a specific PP. CSPP provides the requirements necessary to specify needs for both stand-alone and distributed, multi-user information systems. This covers general-purpose operating systems, database management systems, and other applications.
Tang, H.C., Nguyen T., Chuang T.J., Chin J., Wu, H.F., Lesko, J.; Temperature Effects on Fatigue of Polymer Composites; Proceedings of International Conference on Composites Engineering
Fiber-reinforced polymeric composites provide lightweight, high strength, and corrosive resistance to severe environ-mental exposures. These composites have been extensively used in aerospace and military application over the last three decades and are being extended into civil engineering applications. However, there is little quantitative research on the effects of civil engineering environments, namely, water, sea water, temperature, concrete pore solution, ultraviolet light, and loading on the fatigue of polymeric composites. We have developed a fatigue model, for predicting the fatigue life of fiber-reinforced polymeric composites, that incorporates applied maximum stress, stress amplitude, loading frequency, residual tensile modulus, and material constants. The model has been verified with experimental fatigue data of a glass fiber/vinyl ester composite in various environments: air, fresh water, and saltwater at 30oC. This study continues to investigate the effects on fatigue life by the change of temperature. Both the residual mechanical properties at specified loading cycles and the number of cycles at which the specimens fail are measured. The results show, for the material used in this study, that the fatigue life in these aqueous environments at 65oC is about the same as that at 30oC, but the fatigue life at 4oC is significantly longer than that at 30oC. Based on these experimental data, the material constants, m and C, are derived as functions of temperature, T.
Terrasse, M.N.; A Metamodeling Approach to Evolution; Ninth International Workshop on Foundations of Models and Languages for Data and Objects, DEMM2000 (Database Schema Evolution and Meta-Modeling)
With the increasing complexity of systems being modeled, analysis & design move towards more and more abstract methodologies. Most of them rely on metamodeling tools using multi-view models and the four-layer metamodeling architecture. Our idea is to use the metamodeling approach in order to classify and to constraint the possible evolutions of an information system. Within the domain of UML metamodeling, a refinement of the metamodel-level classification is proposed that includes bases for defining a metric of the evolution (in terms of distance between metamodels).
Terrasse, M.N., Savonnet, M.; Metamodeling with the UML: An Approach to the Formalization of the UML Metamodel; Fifth CAiSE/IFIP8.1 International Workshop on Evaluation of Modeling Methods in Systems Analysis and DesignEMMSAD'00
Due to the evolution of Analysis & Design requirements, the elaboration of formal specifications s becoming the bulk of new development environments. The objective of this paper is to explore the formalization of the UML metamodel without reducing the expressiveness of the Unified Modeling Language. To deal with the ambiguity of the UML metamodel, we use an original approach that relies on the four-layer metamodeling architecture. Our modeling architecture is composed of a meta-metamodeling layer populated with modeling paradigms that describe under which conditions the modeling can be carried out in a given context. Each modeling paradigm is instantiated into a formal metamodel. The metamodel layer is thus populated by an inheritance hierarchy of metamodels: the UML metamodel is the (informal) root of this hierarchy; any non-root metamodel is formalized. This architecture permits us to "delay" the formalization until the target metamodel may be expressed without ambiguity.
Veerappa, B.V., Tang, X.; Superresolution Optical Pick-Up Using Phase Pupil Filter with a Solid Immersion Lens; Optics Communications
Superresolution phase pupil filter in conjunction with solid immersion lens for high density in optical data storage is described. The frequency response of the system is studied. A binary annular phase filter is used in this study. Simulation results are included to show the effectiveness of using such a system with acceptable side lobe effect.
Voorhees, E.M.; The TREC-8 Question Answering Track Report; Included in NIST SP 500-246
The TREC-8 Question Answering track was the first large-scale evaluation of domain-independent question answering systems. This paper summarizes the results of the track by giving a brief overview of the different approaches taken to solve the problem. The most accurate systems found a correct response for more than 2/3 of the questions. Relatively simple bag-of-words approaches were adequate for finding answers when responses could be as long as a paragraph (250 bytes), but more sophisticated processing was necessary for more direct responses (50 bytes).
Voorhees, E.M.; Variations in Relevance Judgments and the Measurement of Retrieval Effectiveness; Information Processing and Management
Test collections have traditionally been used by information retrieval researchers to improve their retrieval strategies. To be viable as a laboratory tool, a collection must reliably rank different retrieval variants according to their true effectiveness. In particular, the relative effectiveness of two retrieval strategies should be insensitive to modest changes in the relevant document set since individual relevance assessments are known to vary widely. The test collections developed in the TREC workshops have become the collections of choice in the retrieval research community. To verify their reliability, NIST investigated the effect changes in the relevance assessments have on the evaluation of retrieval results. Very high correlations were found among the rankings of systems produced using different relevance judgment sets. The high correlations indicate that the comparative evaluation of retrieval performance is stable despite substantial differences in relevance judgments, and thus reaffirm the use of the TREC collections as laboratory tools.
Voorhees, E.M., Harman, D.; The Eighth Text Retrieval Conference (TREC-8); NIST SP 500-246
This report constitutes the proceedings of the eighth Text REtrieval Conference (TREC-8) held in Gaithersburg, Maryland, November 16, 1999. The conference was co-sponsored by the National Institute of Standards and Technology (NIST) and the Defense Advanced Research Projects Agency (DARPA), and was attended by 170 people. Sixty-six groups including participants from 16 different countries were represented. The conference was the eighth in an ongoing series of workshops to evaluate new technologies in text retrieval.
The workshop included plenary sessions, discussion groups, a poster session, and demonstrations. Because the participants in the workshop drew on their personal experiences, they sometimes cited specific vendors and commercial products. The inclusion or omission of a particular company or product implies neither endorsement nor criticism by NIST. Any opinions, findings, and conclusions or recommendations expressed in the individual papers are the authors' own and do not necessarily reflect those of the sponsors.
The sponsorship of the Defense Advanced Research Projects Agency is gratefully acknowledged, as is the tremendous work of the program committee and the track coordinators.
Voorhees, E.M., Tice, D.M.; The TREC-8 Question Answering Track; Proceedings of the Second International Conference on Language Resources and Evaluation, Athens, Greece, May 31-June 2, 2000; 5/31/2000
The TREC-8 Question Answering track was the first large-scale evaluation of domain-independent question answering systems. This paper summarizes the results of the track, including both an overview of the approaches taken to the problem and an analysis of the evaluation methodology. Retrieval results for the more stringent condition in which system responses were limited to 50 bytes showed that explicit linguistic processing was more effective than the bag-of-words approaches that are effective for document retrieval. The use of multiple human assessors to judge the correctness of the systems' responses demonstrated that assessors have legitimate differences of opinion as to correctness even for fact-based, short-answer questions. Evaluations of question answering technology will need to accommodate these differences since eventual end-users of the technology will have similar differences.
Voorhees, E.M., Tice, D.M.; The TREC-8 Question Answering Track Evaluation; Included in NIST SP 500-246
The TREC-8 Question Answering track was the first large-scale evaluation of systems that return answers, as opposed to lists of documents, in response to a question. As a first evaluation, it is important to examine the evaluation methodology itself to understand any limits on the conclusions that can be drawn from the evaluation and possibly to find ways to improve subsequent evaluations. This paper has two main goals: to describe in detail how the evaluation was implemented, and to examine the consequences of the methodology on the comparative performance of the systems participating in the evaluation. The examination uncovered no serious flaws in the methodology, supporting its continued use for question answering evaluation. Nonetheless, redefining the specific task to be performed so that it more closely matches an actual user task does appear warranted.
Voorhees, E.M., Tice, D.M.; Building a Question Answering Test Collection; 23rd Annual International ACM SIGIR Conference
The TREC-8 Question Answering (QA) Track was the first large-scale evaluation of domain-independent question answering systems. In addition to fostering research on the QA task, the track was used to investigate whether the evaluation methodology used for document retrieval is appropriate for a different natural language processing task. As with document relevance judging, assessors had legitimate differences of opinions as to whether a response
actually answers a question, but comparative evaluation of QA systems was stable despite these differences. Creating a reusable QA test collection is fundamentally more difficult than creating a document retrieval test collection since the QA task has no equivalent to document identifiers.
Wallace, D.R.; Using Failure History to Improve Reliability in Information Technology; Data and Analysis Center for Software Newsletter; 3/1/2000
Achieving 100 percent software reliability may seem an unreasonable goal. Software developers and consumers of many software products are largely unsure about the reliability of their product or purchase. Today, many opportunities exist for some assurance of software products. Current practices and issues address process (e.g., CMM, ISO 9000), people (e.g., software engineering degrees, certification exams, licensing) and product (e.g., measurement
of the product) encompass major areas of progress toward software reliability. This presentation discusses one aspect of the product: the usage of history data of faults and failures of software systems, collected from either the development and assurance processes or operational use, to improve reliability of software products. Information contained in these histories characterizes the nature of faults, or defects, for a specific product line. The objectives are to use the history to determine how to prevent faults from entering into the product, to remove faults before the product is released, and to measure a product's frequency profile against others in the same domain. Finally, the histories may indicate problems for which better methods are needed to prevent or detect, hence providing justification for research ideas.
Wallace, D.R., Kuhn, D.R.; Software Quality Lessons from Medical Device Failure Data; NISTIR 6407; 11/1/1999
Most complex systems today contain software, and systems failures activated by software faults can provide lessons for software development practices and software quality assurance. This report presents an analysis of 342 software-related failures of medical devices that caused no death or injury but led to recalls by the manufacturers. The analysis categorizes the failures by their symptoms and faults. Tables provide methods for preventing and detecting the faults. The nature of the faults provides lessons about the value of generally accepted quality practices for prevention and detection methods applied prior to system release. It also provides some insight into the need for formal requirements specification and for improved testing of complex hardware-software systems.
Wang, C.M., Hale, P.D., Coakley, K.J., Clement, T. S.; Uncertainty of Oscilloscope Timebase Distortion Estimate; IEEE Transactions on Instrumentation and Measurement
We study several problems related to the characterization of the timebase in high-speed sampling oscilloscopes. First, we examine the bias of using the method of the first-order approximation to estimate the additive and time jitter noises, and present a procedure to adjust for the bias in the estimates. We then study the bias and variance of a least-squares timebase distortion estimate that uses multiple sets of waveforms. Based on simulations, a method for calculating the uncertainty of the timebase distortion estimate is proposed. We also study the effects of amplitude and phase drifts, as well as jitter error on the estimation of timebase distortion. Results are shown using simulations with parameters that are closely related to those we observe in our laboratory.
Watson, C.I., Grother, P.J., Cassasent, D. P.; Distortion-Tolerant Filter for Elastic-Distorted Fingerprint Matching; NISTIR 6489; 3/29/2000
This paper gives results for using distortion tolerant filters to improve performance of fingerprint correlation matching. Three types of distortion tolerant filters were tested: summation, weighted, and MINACE. A set of 55 fingers were used from NIST Special Database 24 to evaluate the filters. Our results show performance was improved from 49% correct, using one training fingerprint, to 100% correct, using multiple training fingerprints and a
distortion-tolerant MINACE filter, with no false alarms.
Xiao, Yu, L'Hostis, Pierre, Tang, Xiao; An Auto-Focusing Method in Microscopic Testbed for Optical Discs; NIST Journal of Research, Vol. 105, No. 4, July-August 2000; 8/1/2000
An auto-focusing method is described and practically applied to an optical disc test-bed. In this application, an optical microscope was used to create clear pit images of optical discs. A CCD camera generated the graphic signals for the images. A standard deviation value of the gray levels for all pixels in the image is used as a feedback for auto-focusing control. The performance and possible applications of this method are discussed and test results for optical discs are given in this paper.
Yang, G. L., Coakley, K.J.; Likelihood Models for Two Stage Neutron Lifetime Experiments; Physical Review E
At the NIST Cold Neutron Research Facility, a two-stage experiment, which consists of neutron production and neutron decay stages, is underway to determine the neutron lifetime or time to decay. In this paper, statistical methods are developed for estimating the mean neutron lifetime from such experiments. Salient features of the experimental data are that the number, N, of neutrons whose decay times are being recorded is an unobservable random variable and that the decay times are contaminated by background noises in the recording. Under the assumption that neutron productions and decays follow a Markovian birth and death process, we deduce the distribution of N and the decay times subject to a variety of experimental constraints. These distributions serve as likelihood models for estimation of the mean neutron life time. The method of maximum likelihood and the method of minimum chi-square are employed and compared for estimation. The minimum chi-square estimates suitable for binned decay data are shown, by simulation, to be comparable to the maximum likelihood estimates based on the data of exact decay times. The loss of efficiency in using binned data instead of the exact decay times is minimal provided the bin width are reasonably small and the observation period for decay is not too short. Our systematic and unified approach facilitates the application of the developed statistical methods to the study of other similar two-stage experiment of atom decays. It also clarifies some of the ambiguities in the literature in using the conditional distributions for statistical estimation.
Yen, J.H.; An Estimate of Effect Size Based on the Mann-Whitney Statistic; Biometrics
Meta-analysis, the statistical synthesis of results from several different studies, often involves combining estimates of effect size from several experiments. The standardized mean difference is one of the most commonly used estimates of effect size; however, when the data are not normally distributed, nonparametric effect size estimates may be preferable. This paper presents a nonparametric estimate of effect size based on the Mann-Whitney test that combines excellent efficiency with robustness. In addition, estimates of variance and confidence interval procedures for this estimator are provided.
Yen, J.H.; Robust Estimation of Effect Sizes Using Influence Functions; Journal of the American Statistical Association
The estimation of effect sizes is crucial part of meta-analysis. This papers uses influence functions as a fundamental tool in the analysis of estimates of effect size. The generalization to several variables of the influence function provides heuristic information about the robustness of the estimators and a way to calculate their large sample variances, including for non-normal situations. Some commonly used parametric estimators are organized into one of two classes of estimators that we call first order quotient estimators and second order quotient estimators. We provide the influence functions and large sample variance estimates for quotient estimators in general and for certain specific cases. In addition, influence functions are used to analyze several nonparametric estimates and to provide variance estimates where none existed previously. The performance of the various estimators along with their proposed variance estimates and confidence intervals are tested in Monte Carlo experiments.
Yen, J.H.; Trimmed Weighted Means; Journal of the American Statistical Association
In many situations, weighted means can achieve much lower variances than unweighted means by placing more weight on those observations that are more precise. However, that weighted means can be dominated by one or two observations with very large weights raises questions about their robustness. The trimmed weighted mean, by trimming portions of the weights off of either end, retains much of the precision of weighted means while adding robustness. We present asymptotic results based on the theory of weighted empirical functions, including a Central Limit-type theorem, estimates of variance, and procedures for forming confidence intervals. Finally, these procedures are demonstrated and tested using Monte Carlo studies.
Zhao, W., Chellappa, R., Phillips, P.J.; Subspace Linear Discriminant Analysis for Face Recognition; IEEE Transactions on Image Processing
In this correspondence, we describe a holistic face recognition method based on subspace Linear Discriminant Analysis (LDA). Like existing methods, this method consists of two steps: first, the face image is projected into a face subspace via Principal Component Analysis (PCA) where the subspace dimension is carefully chosen, and then the PCA projection vectors are projected into the LDA to construct a linear classifier in the subspace. Experiments show that the dimension of the face subspace is fixed regardless of the image size as long as the image size exceeds the subspace dimension. The property of relative invariance of the subspace dimension enables the system to work with smaller face images without sacrificing performance. The
choice of such a fixed subspace dimension is mainly based on the characteristics of the eigenvectors instead of the commonly used eigenvalues. Such a choice of the subspace dimension enables the system to generate class-separable features via LDA from the full subspace representation. Hence the generalization/overfitting problem can be addressed. In addition, a weighted distance metric guided by the LDA eigenvalues is employed to improve the performance of the subspace LDA method. Experimental results using FERET datasets and the MPEG-7 content set are presented.