支持时间无关激活的分布对象中间件异步模型

时间无关的异步激活方式对于大规模分布式应用、移动应用和企业应用集成都具有重要意义．目前的分布对象中间件虽然支持回调和轮询两种异步机制，但是都不支持时间无关的异步激活方式．针对这一问题，本文基于国防科学技术大学计算机学院在分布对象中间件Starbus平台异步模型方面的研究成果，提出了一种新的异步模型RAAM(Router Agent based Asynchronous Model)，该模型能够支持消息的异步传递和时间无关的激活方式，同时对消息的服务质量提供了很好的支持．在自主研发的分布计算平台Starbus异步子系统中实现了RAAM模型，并与相关工作进行了比较．     

Verifying distributed real-time properties of embedded systems via graph transformations and model checking

Component middleware provides dependable and efficient platforms that support key functional, and quality of service (QoS) needs of distributed real-time embedded (DRE) systems. Component middleware, however, also introduces challenges for DRE system developers, such as evaluating the predictability of DRE system behavior, and choosing the right design alternatives before committing to a specific platform or platform configuration. Model-based technologies help address these issues by enabling design-time analysis, and providing the means to automate the development, deployment, configuration, and integration of component-based DRE systems. To this end, this paper applies model checking techniques to DRE design models using model transformations to verify key QoS properties of component-based DRE systems developed using Real-time CORBA. We introduce a formal semantic domain for a general class of DRE systems that enables the verification of distributed non-preemptive real-time scheduling. Our results show that model-based techniques enable design-time analysis of timed properties and can be applied to effectively predict, simulate, and verify the event-driven behavior of component-based DRE systems. This research was supported by the NSF Grants CCR-0225610 and ACI-0204028 Gabor Madl is a Ph.D. student and a graduate student researcher at the Center for Embedded Computer Systems at the University of California, Irvine. His advisor is Nikil Dutt. His research interests include the formal verification, optimization, component-based composition, and QoS management of distributed real-time embedded systems. He received his M.S. in computer science from Vanderbilt University and in computer engineering from the Budapest University of Technology and Economics. Dr. Sherif Abdelwahed received his Ph.D. degree in Electrical and Computer Engineering from the University of Toronto, Canada, in 2001. During 2000–2001, he was a research scientist with the system diagnosis group at the Rockwell Scientific Company. Since 2001 he has been with the Department of Electrical Engineering and Computer Science at Vanderbilt University as a Research Assistant Professor. His research interests include verification and control of distributed real-time systems, and model-based diagnosis of discrete-event and hybrid systems. Dr. Douglas C. Schmidt is a Professor of Computer Science, Associate Chair of the Computer Science and Engineering program, and a Senior Researcher in the Institute for Software Integrated Systems (ISIS) all at Vanderbilt University. He has published over 300 technical papers and 6 books that cover a range of research topics, including patterns, optimization techniques, and empirical analyses of software frameworks and domain-specific modeling environments that facilitate the development of distributed real-time and embedded (DRE) middleware and applications. Dr. Schmidt has served as a Deputy Office Director and a Program Manager at DARPA, where he lead the national R&D effort on middleware for DRE systems. In addition to his academic research and government service, Dr. Schmidt has over fifteen years of experience leading the development of ACE, TAO, CIAO, and CoSMIC, which are widely used, open-source DRE middleware frameworks and model-driven tools that contain a rich set of components and domain-specific languages that implement patterns and product-line architectures for high-performance DRE systems.     

AgentTeamwork: Coordinating grid-computing jobs with mobile agents

AgentTeamwork is a grid-computing middleware system that dispatches a collection of mobile agents to coordinate a user job over remote computing nodes in a decentralized manner. Its utmost focus is to maintain high availability and dynamic balancing of distributed computing resources to a parallel-computing job. For this purpose, a mobile agent is assigned to each process engaged in the same job, monitors its execution at a different machine, takes its periodical execution snapshot, moves it to a lighter-loaded machine, and resumes it from the latest snapshot upon an accidental crash. The system also restores broken inter-process communication involved in the same job using its error-recoverable socket and mpiJava libraries in collaboration among mobile agents. We have implemented the first version of our middleware including a mobile agent execution platform, error-recoverable socket and mpiJava API libraries, a job wrapper program, and several types of mobile agents such as commander, resource, sentinel, and bookkeeper agents, each orchestrating, allocating resources to, monitoring and maintaining snapshots of a user process respectively. This paper presents AgentTeamwork’s execution model, its implementation techniques, and our performance evaluation using the Java Grande benchmark test programs. Munehiro Fukuda received a B.S. from the College of Information Sciences and an M.S. from the Master’s Program in Science and Enginnering at the University of Tsukuba in 1986 and 1988. He received his M.S. and Ph.D. in Information and Computer Science at the University of California at Irvine in 1995 and 1997, respectively. He worked at IBM Tokyo Research Laboratory from 1988 to 1993 and taught at the University of Tsukuba from 1998 to 2001. Since 2001, he has been an assistant professor at Computing & Software Systems, the University of Washington, Bothell. His research interests include mobile agents, multi-threading, cluster computing, grid computing and distributed simulations. Koichi Kashiwagi received a Bachelor of Science degree from the Faculty of Science, Ehime University in 2000 and a Master of Engineering degree from the Department of Compter Science, Ehime University in 2002. In 2004 he became a research assistant in Department of Compter Science, Ehime University. His research interests include distributed computing, job scheduling, and grid computing. Shin-ya Kobayashi received the B.E. degree, M.E. degree, and Dr.E. degree in Communication Engineering from Osaka University in 1985, 1988, and 1991 respectively. From 1991 to 1999, he was on the faculty of Engineering at Kanazawa University, Japan. From 1999 to 2004, He was an Associate Professor in the Department of Computer Science, Ehime University. He is a Professor at Graduate School of Science and Engineering, Ehime University. His research interests include distributed processing, and parallel processing. He is a member of the Information Processing Society of Japan, the Institute of Electrical Engineers of Japan, IEEE, and ACM.     

CCMPerf: A Benchmarking Tool for CORBA Component Model Implementations

Commercial off-the-shelf (COTS) middleware is now widely used to develop distributed real-time and embedded (DRE) systems. DRE systems are themselves increasingly combined to form systems of systems that have diverse quality of service (QoS) requirements. Earlier generations of COTS middleware, such as Object Request Brokers (ORBs) based on the CORBA 2.x standard, did not facilitate the separation of QoS policies from application functionality, which made it hard to configure and validate complex DRE applications. The new generation of component middleware, such as the CORBA Component Model (CCM) based on the CORBA 3.0 standard, addresses the limitations of earlier generation middleware by establishing standards for implementing, packaging, assembling, and deploying component implementations.There has been little systematic empirical study of the performance characteristics of component middleware implementations in the context of DRE systems. This paper therefore provides four contributions to the study of CCM for DRE systems. First, we describe the challenges involved in benchmarking different CCM implementations. Second, we describe key criteria for comparing different CCM implementations using key black-box and white-box metrics. Third, we describe the design of our CCMPerf benchmarking suite to illustrate test categories that evaluate aspects of CCM implementation to determine their suitability for the DRE domain. Fourth, we use CCMPerf to benchmark CIAO implementation of CCM and analyze the results. These results show that the CIAO implementation based on the more sophisticated CORBA 3.0 standard has comparable DRE performance to that of the TAO implementation based on the earlier CORBA 2.x standard.Arvind S. Krishna is a PhD student in the Electrical Engineering and Computer Science Department at Vanderbilt University and a member of the Institute for Software Integrated Systems. He received his MA in management from the Brila Institute for Technology and Science (BITS), Pilani, India and his MS in computer science from University of California, Irvine. His research interests include patterns, real-time Java technologies for Real-Time Corba, model-integrated QA techniques, and tools for partial evaluation and specialization of middleware. He is a student member of the IEEE and ACM. Contact him at the Inst. for Software Integrated Systems, 2015 Terrace Pl., Nashville, TN 37203.Balachandran Natarajan is a senior staff engineer at the Institute for Software Integrated Systems and a PhD student in electrical engineering and computer science at Vanderbilt University. His research focuses on applying patterns, optimization principles, and frameworks to build high-performance, dependable, and real-time distributed systems. He received his MS in computer science from Washington University. Contact him at the Inst. for Software Integrated Systems, 2015 Terrace Pl., Nashville, TN 37203.Aniruddha Gokhale is an assistant professor in the Electrical Engineering and Computer Science Department at Vanderbilt University and a senior research scientist at the Institute for Software Integrated Systems. His research focuses on real-time component middleware optimizations, distributed systems and networks, model-driven software synthesis applied to component middleware-based distributed systems, and distributed resource management. He received his PhD in computer science from Washington University. Contact him at the Inst. for Software Integrated Systems, 2015 Terrace Pl., Nashville, TN 37203.Douglas C. Schmidt is a professor in the Electrical Engineering and Computer Science Department at Vanderbilt University and a senior research scientist at the Institute for Software Integrated Systems. His research interests include patterns, optimization techniques, and empirical analyses of software frameworks and domain-specific modeling environments that facilitate the development of distributed real-time and embedded middleware and applications running over high-speed networks and embedded system interconnects. He received his PhD in information and computer science at the University of California, Irvine. Contact him at the Inst. for Software Integrated Systems, 2015 Terrace Pl., Nashville, TN 37203.Nanbor Wang is a Research Scientist in the Distributed Technologies Group at the Tech-X Corporation in Boulder, Colorado. He received M.S. and Ph.D. degrees in Computer Science from Washington University in St. Louis, Missouri. While working for his degree, he also worked as a Research Associate in the Center of Distributed Object Computing in the Department of Computer Science where he conducted research on design, implementation and analysis of object-oriented and component-based techniques for development of distributed systems and management of extra-functional concerns. Dr. Wangs work currently focuses on developing and applying middleware techniques, such as CORBA and Grid Computing, for enabling distributed and parallel scientific applications, such as, distributed data analysis, remote visualization and collaboration, and, work-flow management for large-scale scientific applications.Gautam H. Thaker was born in Amdavad, India, in 1955. He holds a BSEE (75) and MSEE (77) from Clemson University, Clemson, SC. He spent the 85-86 academic year at M.I.T. as a visiting researcher. His research interests include analysis, design, construction and validation of real-time, command and control systems. In particular he has focused on interactions between operating systems, networking protocols, and middleware technologies.     

A note on consistency in asynchronous multicaches

Summary This note examines and contrasts the choice of finite versus infinite histories as the framework for analysing the behaviour of an asynchronous multicache scheme. Mike Livesey is currently a Lecturer in Computer Science at the University of St. Andrews, Scotland. His research interests are centred on distributed systems, particularly the specification and verification of distributed protocols. Dr. Livesey received a BA in mathematics from Cambridge University in 1970, an MSc in computer science from Essex University in 1973 and a PhD in computer science form St. Andrews University in 1987. He has also taught at other universities in Britain and New Zealand, and been employed by Marconi-Elliott Computer Systems Ltd.     

Interactive online learning

This paper describes a system for visual object recognition based on mobile augmented reality gear. The user can train the system to the recognition of objects online using advanced methods of interaction with mobile systems: Hand gestures and speech input control “virtual menus,” which are displayed as overlays within the camera image. Here we focus on the underlying neural recognition system, which implements the key requirement of an online trainable system—fast adaptation to novel object data. The neural three-stage architecture can be adapted in two modes: In a fast training mode (FT), only the last stage is adapted, whereas complete training (CT) rebuilds the system from scratch. Using FT, online acquired views can be added at once to the classifier, the system being operational after a delay of less than a second, though still with reduced classification performance. In parallel, a new classifier is trained (CT) and loaded to the system when ready. The text was submitted by the authors in English. Gunther Heidemann was born in 1966. He studied physics at the Universities of Karlsruhe and Münster and received his PhD (Eng.) from Bielefeld University in 1998. He is currently working within the collaborative research project “Hybrid Knowledge Representation” of the SFB 360 at Bielefeld University. His fields of research are mainly computer vision, robotics, neural networks, data mining, bonification, and hybrid systems. Holger Bekel was born in 1970. He received his BS degree from the University of Bielefeld, Germany, in 1997. In 2002 he received a diploma in Computer Science from the University of Bielefeld. He is currently pursuing a PhD program in Computer Science at the University of Bielefeld, working within the Neuroinformatics Group (AG Neuroinformatik) in the project VAMPIRE (Visual Active Memory Processes and Interactive Retrieval). His fields of research are active vision and data mining. Ingo Bax was born in 1976. He received a diploma in Computer Science from the University of Bielefeld in 2002. He is currently pursuing a PhD program in Computer Science at the Neuroinformatics Group of the University of Bielefeld, working within the VAMPIRE project. His fields of interest are cognitive computer vision and pattern recognition. Helge J. Ritter was born 1958. He studied physics and mathematics at the Universities of Bayreuth, Heidelberg and Munich. After a PhD in physics at Technical University of Munich in 1988, he visited the Laboratory of Computer Science at Helsinki University of Technology and the Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign. Since 1990 he has headed the Neuroinformatics Group at the Faculty of Technology, Bielefeld University. His main interests are principles of neural computation and their application to building intelligent systems. In 1999, she was awarded the SEL Alcatel Research Prize, and in 2001, the Leibniz Prize of the German Research Foundation DFG.     

Adaptive group scheduling mechanism using mobile agents in peer-to-peer grid computing environment

Peer-to-peer grid computing is an attractive computing paradigm for high throughput applications. However, both volatility due to the autonomy of volunteers (i.e., resource providers) and the heterogeneous properties of volunteers are challenging problems in the scheduling procedure. Therefore, it is necessary to develop a scheduling mechanism that adapts to a dynamic peer-to-peer grid computing environment. In this paper, we propose a Mobile Agent based Adaptive Group Scheduling Mechanism (MAAGSM). The MAAGSM classifies and constructs volunteer groups to perform a scheduling mechanism according to the properties of volunteers such as volunteer autonomy failures, volunteer availability, and volunteering service time. In addition, the MAAGSM exploits a mobile agent technology to adaptively conduct various scheduling, fault tolerance, and replication algorithms suitable for each volunteer group. Furthermore, we demonstrate that the MAAGSM improves performance by evaluating the scheduling mechanism in Korea@Home. SungJin Choi is a Ph.D. student in the Department of Computer Science and Engineering at Korea University. His research interests include mobile agent, peer-to-peer computing, grid computing, and distributed systems. Mr. Choi received a M.S. in computer science from Korea University. He is a student member of the IEEE. MaengSoon Baik is a senior research member at the SAMSUNG SDS Research & Develop Center. His research interests include mobile agent, grid computing, server virtualization, storage virtualization, and utility computing. Dr. Baik received a Ph.D. in computer science from Korea University. JoonMin Gil is a professor in the Department of Computer Science Education at Catholic University of Daegu, Korea. His recent research interests include grid computing, distributed and parallel computing, Internet computing, P2P networks, and wireless networks. Dr. Gil received his Ph.D. in computer science from Korea University. He is a member of the IEEE and the IEICE. SoonYoung Jung is a professor in the Department of Computer Science Education at Korea University. His research interests include grid computing, web-based education systems, database systems, knowledge management systems, and mobile computing. Dr. Jung received his Ph.D. in computer science from Korea University. ChongSun Hwang is a professor in the Department of Computer Science and Engineering at Korea University. His research interests include distributed systems, distributed algorithms, and mobile computing. Dr. Hwang received a Ph.D. in statistics and computer science from the University of Georgia.     

Efficient algorithms for optimistic crash recovery

Summary Recovery from transient processor failures can be achieved by using optimistic message logging and checkpointing. The faulty processorsroll back, and some/all of the non-faulty processors also may have to roll back. This paper formulates the rollback problem as a closure problem. A centralized closure algorithm is presented together with two efficient distributed implementations. Several related problems are also considered and distributed algorithms are presented for solving them. S. Venkatesan received the B. Tech. and M. Tech degrees from the Indian Institute of Technology, Madras in 1981 and 1983, respectively and the M.S. and Ph.D. degrees in Computer Science from the University of Pittsburgh in 1985 and 1988. He joined the University of Texas at Dallas in January 1989, where he is currently an Assistant Professor of Computer Science. His research interests are in fault-tolerant distributed systems, distributed algorithms, testing and debugging distributed programs, fault-tolerant telecommunication networks, and mobile computing. Tony Tony-Ying Juang is an Associate Professor of Computer Science at the Chung-Hwa Polytechnic Institute. He received the B.S. degree in Naval Architecture from the National Taiwan University in 1983 and his M.S. and Ph.D. degrees in Computer Science from the University of Texas at Dallas in 1989 and 1992, respectively. His research interests include distributed algorithms, fault-tolerant distributed computing, distributed operating systems and computer communications.This research was supported in part by NSF under Grant No. CCR-9110177 and by the Texas Advanced Technology Program under Grant No. 9741-036     

One-bit algorithms

Many algorithms in distributed systems assume that the size of a single message depends on the number of processors. In this paper, we assume in contrast that messages consist of a single bit. Our main goal is to explore how the one-bit translation of unbounded message algorithms can be sped up by pipelining. We consider two problems. The first is routing between two processors in an arbitrary network and in some special networks (ring, grid, hypercube). The second problem is coloring a synchronous ring with three colors. The routing problem is a very basic subroutine in many distributed algorithms; the three coloring problem demonstrates that pipelining is not always useful. Amotz Bar-Noy received his B.Sc. degree in Mathematics and Computer Science in 1981, and his Ph.D. degree in Computer Science in 1987, both from the Hebrew University of Jerusalem, Israel. Between 1987 and 1989 he was a post-doctoral fellow in the Department of Computer Science at Stanford University. He is currently a visiting scientist at the IBM Thomas J. Watson Research Center. His current research interests include the theoretical aspects of distributed and parallel computing, computational complexity and combinatorial optimization. Joseph (Seffi) Naor received his B.A. degree in Computer Science in 1981 from the Technion, Israel Institute of Technology. He received his M.Sc. in 1983 and Ph.D. in 1987 in Computer Science, both from the Hebrew University of Jerusalem, Israel. Between 1987 and 1988 he was a post-doctoral fellow at the University of Southern California, Los Angeles, CA. Since 1988 he has been a post-doctoral fellow in the Department of Computer Science at Stanford University. His research interests include combinatorial optimization, randomized algorithms, computational complexity and the theoretical aspects of parallel and distributed computing. Moni Naor received his B.A. in Computer Science from the Technion, Israel Institute of Technology, in 1985, and his Ph.D. in Computer Science from the University of California at Berkeley in 1989. He is currently a visiting scientist at the IBM Almaden Research Center. His research interests include computational complexity, data structures, cryptography, and parallel and distributed computation.Supported in part by a Weizmann fellowship and by contract ONR N00014-85-C-0731Supported by contract ONR N00014-88-K-0166 and by a grant from Stanford's Center for Integrated Systems. This work was done while the author was a post-doctoral fellow at the University of Southern California, Los Angeles, CAThis work was done while the author was with the Computer Science Division, University of California at Berkeley, and Supported by NSF grant DCR 85-13926     

S-Club: an overlay-based efficient service discovery mechanism in CROWN Grid

Information service plays a key role in grid system, handles resource discovery and management process. Employing existing information service architectures suffers from poor scalability, long search response time, and large traffic overhead. In this paper, we propose a service club mechanism, called S-Club, for efficient service discovery. In S-Club, an overlay based on existing Grid Information Service (GIS) mesh network of CROWN is built, so that GISs are organized as service clubs. Each club serves for a certain type of service while each GIS may join one or more clubs. S-Club is adopted in our CROWN Grid and the performance of S-Club is evaluated by comprehensive simulations. The results show that S-Club scheme significantly improves search performance and outperforms existing approaches. Chunming Hu is a research staff in the Institute of Advanced Computing Technology at the School of Computer Science and Engineering, Beihang University, Beijing, China. He received his B.E. and M.E. in Department of Computer Science and Engineering in Beihang University. He received the Ph.D. degree in School of Computer Science and Engineering of Beihang University, Beijing, China, 2005. His research interests include peer-to-peer and grid computing; distributed systems and software architectures. Yanmin Zhu is a Ph.D. candidate in the Department of Computer Science, Hong Kong University of Science and Technology. He received his B.S. degree in computer science from Xi’an Jiaotong University, Xi’an, China, in 2002. His research interests include grid computing, peer-to-peer networking, pervasive computing and sensor networks. He is a member of the IEEE and the IEEE Computer Society. Jinpeng Huai is a Professor and Vice President of Beihang University. He serves on the Steering Committee for Advanced Computing Technology Subject, the National High-Tech Program (863) as Chief Scientist. He is a member of the Consulting Committee of the Central Government’s Information Office, and Chairman of the Expert Committee in both the National e-Government Engineering Taskforce and the National e-Government Standard office. Dr. Huai and his colleagues are leading the key projects in e-Science of the National Science Foundation of China (NSFC) and Sino-UK. He has authored over 100 papers. His research interests include middleware, peer-to-peer (P2P), grid computing, trustworthiness and security. Yunhao Liu received his B.S. degree in Automation Department from Tsinghua University, China, in 1995, and an M.A. degree in Beijing Foreign Studies University, China, in 1997, and an M.S. and a Ph.D. degree in computer science and engineering at Michigan State University in 2003 and 2004, respectively. He is now an assistant professor in the Department of Computer Science and Engineering at Hong Kong University of Science and Technology. His research interests include peer-to-peer computing, pervasive computing, distributed systems, network security, grid computing, and high-speed networking. He is a senior member of the IEEE Computer Society. Lionel M. Ni is chair professor and head of the Computer Science and Engineering Department at Hong Kong University of Science and Technology. Lionel M. Ni received the Ph.D. degree in electrical and computer engineering from Purdue University, West Lafayette, Indiana, in 1980. He was a professor of computer science and engineering at Michigan State University from 1981 to 2003, where he received the Distinguished Faculty Award in 1994. His research interests include parallel architectures, distributed systems, high-speed networks, and pervasive computing. A fellow of the IEEE and the IEEE Computer Society, he has chaired many professional conferences and has received a number of awards for authoring outstanding papers.     

Distributed optimistic concurrency control with reduced rollback

Concurrency control algorithms have traditionally been based on locking and timestamp ordering mechanisms. Recently optimistic schemes have been proposed. In this paper a distributed, multi-version, optimistic concurrency control scheme is described which is particularly advantageous in a query-dominant environment. The drawbacks of the original optimistic concurrency control scheme, namely that inconsistent views may be seen by transactions (potentially causing unpredictable behavior) and that read-only transactions must be validated and may be rolled back, have been eliminated in the proposed algorithm. Read-only transactions execute in a completely asynchronous fashion and are therefore processed with very little overhead. Furthermore, the probability that read-write transactions are rolled back has been reduced by generalizing the validation algorithm. The effects of global transactions on local transaction processing are minimized. The algorithm is also free from dedlock and cascading rollback problems. Divyakant Agrawal is currently a graduate student in the Department of Computer Science at the State University of New York at Stony Brook. He received his B.E. degree from Birla Institute of Technology and Science, Pilani, India in 1980. He worked with Tata Burroughs Limited, from 1980 to 1982. He completed his M.S. degree in Computer Science from SUNY at Stony Brook in 1984. His research interests include design of algorithms for concurrent systems, optimistic protocols and distributed systems. Arthur Bernstein is a Professor of Computer Science at the State University of New York at Stony Brook. His research is concerned with the design and verification of algorithms involving asynchronous activity and with languages for expressing such algorithms. Pankaj Gupta is currently a graduate student in the Department of Computer Science at the State University of New York at Stony Brook. He received M.S. degree in Electrical Engineering from SUNY at Stony Brook in 1982 and M.S. degree in Computer Science from SUNY at Stony Brook in 1985. His research interests include distributed systems, concurrency control, and databases. Soumitra Sengupta is currently a graduate student in the Department of Computer Science at the State University of New York at Stony Brook. He received his B.E. degree from Birla Institute of Technology and Science, Pilani, India in 1980. He worked with Tata Consultancy Services, from 1980 to 1982. He completed his M.S. degree in Computer Science from SUNY at Stony Brook in 1984. His research interests include distributed algorithms, logic databases and concurrency control.This work was supported by the National Science Foundation under grant, DCR-8502161 and the Air Force Office of Scientific Research under grant AFOSR 810197     

Information access in multimedia databases based on feature models

With the increasing popularity of the WWW, the main challenge in computer science has become content-based retrieval of multimedia objects. Access to multimedia objects in databases has long been limited to the information provided in manually assigned keywords. Now, with the integration of feature-detection algorithms in database systems software, content-based retrieval can be fully integrated with query processing. We describe our experimentation platform under development, making database technology available to multimedia. Our approach is based on the new notion of feature databases. Its architecture fully integrates traditional query processing and content-based retrieval techniques. Arjen P. de Vries, Ph.D.: He received his Ph.D. in Computer Science from the University of Twente in 1999, on the integration of content management in database systems. He is especially interested in the new requirements on the design of database systems to support content-based retrieval in multimedia digital libraries. He has continued to work on multimedia database systems as a postdoc at the CWI in Amsterdam as well as University of Twente. Menzo Windhouwer: He received his MSc in Computer Science and Management from the University of Amsterdam in 1997. Currently he is working in the CWI Database Research Group on his Ph.D., which is concerned with multimedia indexing and retrieval using feature grammars. Peter M.G. Apers, Ph.D.: He is a full professor in the area of databases at the University of Twente, the Netherlands. He obtained his MSc and Ph.D. at the Free University, Amsterdam, and has been a visiting researcher at the University of California, Santa Cruz and Stanford University. His research interests are query optimization in parallel and distributed database systems to support new application domains, such as multimedia applications and WWW. He has served on the program committees of major database conferences: VLDB, SIGMOD, ICDE, EDBT. In 1996 he was the chairman of the EDBT PC. In 2001 he will, for the second time, be the chairman of the European PC of the VLDB. Currently he is coordinating Editor-in-Chief of the VLDB Journal, editor of Data & Knowledge Engineering, and editor of Distributed and Parallel Databases. Martin Kersten, Ph.D.: He received his PhD in Computer Science from the Vrije Universiteit in 1985 on research in database security, whereafter he moved to CWI to establish the Database Research Group. Since 1994 he is professor at the University of Amsterdam. Currently he is heading a department involving 60 researchers in areas covering BDMS architectures, datamining, multimedia information systems, and quantum computing. In 1995 he co-founded Data Distilleries, specialized in data mining technology, and became a non-executive board member of the software company Consultdata Nederland. He has published ca. 130 scientific papers and is member of the editorial board of VLDB journal and Parallel and Distributed Systems. He acts as a reviewer for ESPRIT projects and is a trustee of the VLDB Endowment board.     

Integrating On-Line Performance Visualization and Real-Time System Design

Emerging parallel or distributed, heterogeneous real-time computer systems with many disparate constraints and requirements would benefit from a unifying and comprehensive systems engineering support in the design, testing and deployment phases, which interfaces with a human at a very high level and efficiently handles the system complexity. We present an approach to integration of (1) a compiler- and Constraint Logic Programming-based approach to design and engineering of real-time systems, and (2) an on-line performance analysis and visualization technology. An example distributed real-time system is used to help describe the integrated approach. Details are presented about how the involved technologies are used to help system developers and users achieve better system performance through on-line repair and reconfiguration. This work was supported in part by NSF grants No. 0334035, 0098017, and EIA-9911074 and NIH grant no.EB002238-01. Aleksandar M. Bakić is a lead engineer at Vlatacom, Ltd. His research interests include design and engineering of complex, distributed real-time systems; instrumentation, performance visualization and steering; high-level programming languages, compiler-based technologies and software design automation. He received his BS in computer engineering from the School of Electrical Engineering, Belgrade, Serbia and Montenegro, and his MS and PhD in computer science from Michigan State University. Matt Mutka received the B.S. degree in electrical engineering from the University of Missouri-Rolla in 1979, the M.S. degree in electrical engineering from Stanford University in 1980, and the Ph.D. degree in Computer Science from the University of Wisconsin-Madison in 1988. In 1989 he joined the faculty of the Department of Computer Science, Michigan State University, East Lansing, Michigan, where he is currently an associate professor.† He was a visiting scholar at the University of Helsinki, Helsinki Finland, in 1988–1989, and in 2002, and a member of technical staff at Bell Laboratories in Denver, Colorado from 1979–1982. His current research interests include mobile computing, wireless networking, multimedia networking, and network security issues.     

Behavioural notions for elementary net systems

We study the relationships between a number of behavioural notions that have arisen in the theory of distributed computing. In order to sharpen the under-standing of these relationships we apply the chosen behavioural notions to a basic net-theoretic model of distributed systems called elementary net systems. The behavioural notions that are considered here are trace languages, non-sequential processes, unfoldings and event structures. The relationships between these notions are brought out in the process of establishing that for each elementary net system, the trace language representation of its behaviour agrees in a strong way with the event structure representation of its behaviour. M. Nielsen received a Master of Science degree in mathematics and computer science in 1973, and a Ph.D. degree in computer science in 1976 both from Aarhus University, Denmark. He has held academic positions at Department of Computer Science, Aarhus University, Denmark since 1976, and was visiting researcher at Computer Science Department, University of Edinburgh, U.K., 1977–79, and Computer Laboratory, Cambridge University, U.K., 1986. His research interest is in the theory of distributed computing. Grzegorz Rozenberg received a master of engineering degree from the Department of Electronics (section computers) of the Technical University of Warsaw in 1964 and a Ph.D. in mathematics from the Institute of Mathematics of the Polish Academy of Science in 1968. He has held acdeemic positions at the Institute of Mathematics of the Polish Academy of Science, the Department of Mathematics of Utrecht University, the Department of Computer Science at SUNY at Buffalo, and the Department of Mathematics of the University of Antwerp. He is currently Professor at the Department of Computer Science of Leiden University and Adjoint Professor at the Department of Computer Science of the University of Colorado at Boulder. His research interests include formal languages and automata theory, theory of graph transformations, and theory of concurrent systems. He is currently President of the European Association for Theoretical Computer Science (EATCS). P.S. Thiagarajan received the Bachelor of Technology degree from the Indian Institute of Technology, Madras, India in 1970. He was awarded the Ph.D. degree by Rice University, Houston Texas, U.S.A, in 1973. He has been a Research Associate at the Massachusetts Institute of Technology, Cambridge a Staff Scientist at the Geosellschaft für Mathematik und Datenverarbeitung, St. Augustin, a Lektor at Århus University, Århus and an Associate Professor at the Institute of Mathematical Sciences, Madras. He is currently a Professor at the School of Mathematics, SPIC Science Foundation, Madras. He research intest is in the theory of distributed computing.     

Some impossibility results in interprocess synchronization

Summary In this paper we construct a formal specification of the problem of synchronizing asynchronous processes under strong fairness. We prove that strong interaction fairness is impossible for binary (and hence for multiway) interactions and strong process fairness is impossible for multiway interactions. Yih-Kuen Tsay received his B.S. degree form National Taiwan University in 1984 and his M.S. degree from UCLA in 1989. He is currently a Ph.D. candidate in the UCLA Computer Science Department. His research interests include distributed algorithms, fault-tolerant systems, and specification and verification of concurrent programs. Rajive L. Bagrodia received the B. Tech. degree in Electrical Engineering from the Indian Institute of Technology, Bombay in 1981 and the M.A. and Ph.D. degrees in Computer Science from the University of Texas at Austin in 1983 and 1987 respectively. He is currently an Assistant Professor in the Computer Science Department at UCLA. His research interests include parallel languages, distributed algorithms, parallel simulation and software design methodologies. He was selected as a 1991 Presidential Young Investigator by NSF.This research was partially supported by NSF PYI Award number ASC9157610 and by ONR under grant N00014-91-J1605     

Preference update for e-commerce applications: Model,language, and processing

It is likely that customers issue requests based on out-of-date information in e-commerce application systems. Hence, the transaction failure rates would increase greatly. In this paper, we present a preference update model to address this problem. A preference update is an extended SQL update statement where a user can request the desired number of target data items by specifying multiple preferences. Moreover, the preference update allows easy extraction of criteria from a set of concurrent requests and, hence, optimal decisions for the data assignments can be made. We propose a group evaluation strategy for preference update processing in a multidatabase environment. The experimental results show that the group evaluation can effectively increase the customer satisfaction level with acceptable cost. Peng Li is the Chief Software Architect of didiom LLC. Before that, he was a visiting assistant professor of computer science department in Western Kentucky University. He received his Ph.D. degree of computer science from the University of Texas at Dallas. He also holds a B.Sc. and M.S. in Computer Science from the Renmin University of China. His research interests include database systems, database security, transaction processing, distributed and Internet computer and E-commerce. Manghui Tu received a Bachelor degree of Science from Wuhan University, P.R. China in 1996, and a Master Degree in Computer Science from the University of Texas at Dallas 2001. He is currently working toward the PhD degree in the Department of Computer Science at the University of Texas at Dallas. Mr. Tu’s research interests include distributed systems, grid computing, information security, mobile computing, and scientific computing. His PhD research work focus on the data management in secure and high performance data grid. He is a student member of the IEEE. I-Ling Yen received her BS degree from Tsing-Hua University, Taiwan, and her MS and PhD degrees in Computer Science from the University of Houston. She is currently an Associate Professor of Computer Science at the University of Texas at Dallas. Dr. Yen’s research interests include fault-tolerant computing, security systems and algorithms, distributed systems, Internet technologies, E-commerce, and self-stabilizing systems. She had published over 100 technical papers in these research areas and received many research awards from NSF, DOD, NASA, and several industry companies. She has served as Program Committee member for many conferences and Program Chair/Co-Chair for the IEEE Symposium on Application-Specific Software and System Engineering & Technology, IEEE High Assurance Systems Engineering Symposium, IEEE International Computer Software and Applications Conference, and IEEE International Symposium on Autonomous Decentralized Systems. She is a member of the IEEE. Zhonghang Xia received the B.S. degree in applied mathematics from Dalian University of Technology in 1990, the M.S. degree in Operations Research from Qufu Normal University in 1993, and the Ph.D. degree in computer science from the University of Texas at Dallas in 2004. He is now an assistant professor in the Department of Computer Science, Western Kentucky University, Bowling Green, KY. His research interests are in the area of multimedia computing and networking, distributed systems, and data mining.     

InfoFilter: Supporting quality of service for fresh information delivery

With the explosive growth of the Internet and World Wide Web comes a dramatic increase in the number of users that compete for the shared resources of distributed system environments. Most implementations of application servers and distributed search software do not distinguish among requests to different web pages. This has the implication that the behavior of application servers is quite unpredictable. Applications that require timely delivery of fresh information consequently suffer the most in such competitive environments. This paper presents a model of quality of service (QoS) and the design of a QoS-enabled information delivery system that implements such a QoS model. The goal of this development is two-fold. On one hand, we want to enable users or applications to specify the desired quality of service requirements for their requests so that application-aware QoS adaptation is supported throughout the Web query and search processing. On the other hand, we want to enable an application server to customize how it should respond to external requests by setting priorities among query requests and allocating server resources using adaptive QoS control mechanisms. We introduce the Infopipe approach as the systems support architecture and underlying technology for building a QoS-enabled distributed system for fresh information delivery. Ling Liu, Ph.D.: She is an associate professor at the College of Computing, Georgia Institute of Technology. She received her Ph.D. from Tilburg University, The Netherlands in 1993. Her research interests are in the area of large-scale data intensive systems and its applications in distributed, mobile, multimedia, and Internet computing environments. Her work has focused on systems support for creating, searching, manipulating, and monitoring streams of information in wide area networked information systems. She has published more than 70 papers in internal journals or international conferences, and has served on more than 20 program committees in the area of data engineering, databases, and knowledge and information management. Calton Pu, Ph. D.: He is a Professor and John P. Imlay, Jr. Chair in Software at the College of Computing, Georgia Institute of Technology. Calton received his Ph.D. from University of Washington in 1986. He leads the Infosphere expedition project, which is building the system software to support the next generation information flow applications. Infosphere research includes adaptive operating system kernels, communications middleware, and distributed information flow applications. His past research included operating system projects such as Synthetix and Microfeedback, extended transaction projects such as Epsilon Serializability, and Internet data management. He has published more than 125 journal and conference papers, and served on more than 40 program committees. Karsten Schwan, Ph.D.: He is a professor in the College of Computing at the Georgia Institute of Technology. He received the M.Sc. and Ph.D. degrees from Carnegie-Mellon University in Pittsburgh, Pennsylvania. He directs the IHPC project for high performance cluster computing at Georgia Tech. His current research addresses the interactive nature of modern high performance applications (i.e., online monitoring and computational steering), the development of efficient and object-based middleware, the operating system support for distributed and parallel programs, and the online configuration of applications for distributed real-time applications and for communication protocols. Jonathan Walpole, Ph.D.: He is a Professor in the Computer Science and Engineering Department at oregon Graduate Institute of Science and Technology. He received his Ph.D. in Computer Science from Lancaster University, U.K. in 1987. His research interests are in the area of adaptive systems software and its application in distributed, mobile, multimedia computing environments. His work has focused on quality of service specification, adaptive resource management and dynamic specialization for enhanced performance, survivability and evolvability of large software systems, and he has published extensively in these areas.     

A study of the model and algorithms for handling location-dependent continuous queries

Advances in wireless and mobile computing environments allow a mobile user to access a wide range of applications. For example, mobile users may want to retrieve data about unfamiliar places or local life styles related to their location. These queries are called location-dependent queries. Furthermore, a mobile user may be interested in getting the query results repeatedly, which is called location-dependent continuous querying. This continuous query emanating from a mobile user may retrieve information from a single-zone (single-ZQ) or from multiple neighbouring zones (multiple-ZQ). We consider the problem of handling location-dependent continuous queries with the main emphasis on reducing communication costs and making sure that the user gets correct current-query result. The key contributions of this paper include: (1) Proposing a hierarchical database framework (tree architecture and supporting continuous query algorithm) for handling location-dependent continuous queries. (2) Analysing the flexibility of this framework for handling queries related to single-ZQ or multiple-ZQ and propose intelligent selective placement of location-dependent databases. (3) Proposing an intelligent selective replication algorithm to facilitate time- and space-efficient processing of location-dependent continuous queries retrieving single-ZQ information. (4) Demonstrating, using simulation, the significance of our intelligent selective placement and selective replication model in terms of communication cost and storage constraints, considering various types of queries. Manish Gupta received his B.E. degree in Electrical Engineering from Govindram Sakseria Institute of Technology & Sciences, India, in 1997 and his M.S. degree in Computer Science from University of Texas at Dallas in 2002. He is currently working toward his Ph.D. degree in the Department of Computer Science at University of Texas at Dallas. His current research focuses on AI-based software synthesis and testing. His other research interests include mobile computing, aspect-oriented programming and model checking. Manghui Tu received a Bachelor degree of Science from Wuhan University, P.R. China, in 1996, and a Master's Degree in Computer Science from the University of Texas at Dallas 2001. He is currently working toward the Ph.D. degree in the Department of Computer Science at the University of Texas at Dallas. Mr. Tu's research interests include distributed systems, wireless communications, mobile computing, and reliability and performance analysis. His Ph.D. research work focuses on the dependent and secure data replication and placement issues in network-centric systems. Latifur R. Khan has been an Assistant Professor of Computer Science department at University of Texas at Dallas since September 2000. He received his Ph.D. and M.S. degrees in Computer Science from University of Southern California (USC) in August 2000 and December 1996, respectively. He obtained his B.Sc. degree in Computer Science and Engineering from Bangladesh University of Engineering and Technology, Dhaka, Bangladesh, in November of 1993. Professor Khan is currently supported by grants from the National Science Foundation (NSF), Texas Instruments, Alcatel, USA, and has been awarded the Sun Equipment Grant. Dr. Khan has more than 50 articles, book chapters and conference papers focusing in the areas of database systems, multimedia information management and data mining in bio-informatics and intrusion detection. Professor Khan has also served as a referee for database journals, conferences (e.g. IEEE TKDE, KAIS, ADL, VLDB) and he is currently serving as a program committee member for the 11th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (SIGKDD2005), ACM 14th Conference on Information and Knowledge Management (CIKM 2005), International Conference on Database and Expert Systems Applications DEXA 2005 and International Conference on Cooperative Information Systems (CoopIS 2005), and is program chair of ACM SIGKDD International Workshop on Multimedia Data Mining, 2004. Farokh Bastani received the B.Tech. degree in Electrical Engineering from the Indian Institute of Technology, Bombay, and the M.S. and Ph.D. degrees in Computer Science from the University of California, Berkeley. He is currently a Professor of Computer Science at the University of Texas at Dallas. Dr. Bastani's research interests include various aspects of the ultrahigh dependable systems, especially automated software synthesis and testing, embedded real-time process-control and telecommunications systems and high-assurance systems engineering. Dr. Bastani was the Editor-in-Chief of the IEEE Transactions on Knowledge and Data Engineering (IEEE-TKDE). He is currently an emeritus EIC of IEEE-TKDE and is on the editorial board of the International Journal of Artificial Intelligence Tools, the International Journal of Knowledge and Information Systems and the Springer-Verlag series on Knowledge and Information Management. He was the program cochair of the 1997 IEEE Symposium on Reliable Distributed Systems, 1998 IEEE International Symposium on Software Reliability Engineering, 1999 IEEE Knowledge and Data Engineering Workshop, 1999 International Symposium on Autonomous Decentralised Systems, and the program chair of the 1995 IEEE International Conference on Tools with Artificial Intelligence. He has been on the program and steering committees of several conferences and workshops and on the editorial boards of the IEEE Transactions on Software Engineering, IEEE Transactions on Knowledge and Data Engineering and the Oxford University Press High Integrity Systems Journal. I-Ling Yen received her B.S. degree from Tsing-Hua University, Taiwan, and her M.S. and Ph.D. degrees in Computer Science from the University of Houston. She is currently an Associate Professor of Computer Science at University of Texas at Dallas. Dr. Yen's research interests include fault-tolerant computing, security systems and algorithms, distributed systems, Internet technologies, E-commerce and self-stabilising systems. She has published over 100 technical papers in these research areas and received many research awards from NSF, DOD, NASA and several industry companies. She has served as Program Committee member for many conferences and Program Chair/Cochair for the IEEE Symposium on Application-Specific Software and System Engineering & Technology, IEEE High Assurance Systems Engineering Symposium, IEEE International Computer Software and Applications Conference, and IEEE International Symposium on Autonomous Decentralized Systems. She has also served as a guest editor for a theme issue of IEEE Computer devoted to high-assurance systems.     

Improving retrieval performance by region constraints and relevance feedback

In this paper, region features and relevance feedback are used to improve the performance of CBIR. Unlike existing region-based approaches where either individual regions are used or only simple spatial layout is modeled, the proposed approach simultaneously models both region properties and their spatial relationships in a probabilistic framework. Furthermore, the retrieval performance is improved by an adaptive filter based relevance feedback. To illustrate the performance of the proposed approach, extensive experiments have been carried out on a large heterogeneous image collection with 17,000 images, which render promising results on a wide variety of queries.