Rank order filters and priority queues

Summary A derivation of a parallel algorithm for rank order filtering is presented. Both derivation and result differ from earlier designs: the derivations are less complicated and the result allows a number of different implementations. The same derivation is used to design a collection of priority queues. Both filters and priority queues are highly efficient: they have constant response time and small latency. Anne Kaldewaij received an M.Sc. degree in Mathematics from the University of Utrecht (The Netherlands) and a Ph.D. degree in Computing Science from the Eindhoven University of Technology. Currently, he is associate professor in Computing Science at Eindhoven University. His research includes parallel programming and the design of algorithms and data structures. He enjoys teaching and he has written a number of textbooks on mathematics and programming. Jan Tijmen Udding received an M.Sc. degree in Mathematics in 1980 and a Ph.D. degree in Computing Science in 1984 from Eindhoven University of Technology. Currently, he is associate professor at Groningen University. His main research interests are mathematical aspects of VLSI, program derivation and correctness, and functional programming.     

QoS Control Strategies for High-Quality Video Processing

Video processing in software is often characterized by highly fluctuating, content-dependent processing times, and a limited tolerance for deadline misses. We present an approach that allows close-to-average-case resource allocation to a single video processing task, based on asynchronous, scalable processing, and QoS adaptation. The QoS adaptation balances different QoS parameters that can be tuned, based on user-perception experiments: picture quality, deadline misses, and quality changes. We model the balancing problem as a discrete stochastic decision problem, and propose two solution strategies, based on a Markov decision process and reinforcement learning, respectively. We enhance both strategies with a compensation for structural (non-stochastic) load fluctuations. Finally, we validate our approach by means of simulation experiments, and conclude that both enhanced strategies perform close to the theoretical optimum.Clemens Wüst received the M.Sc. degree in mathematics with honors from the University of Groningen, The Netherlands. Since then, he has been with the Philips Research Laboratories in Eindhoven, The Netherlands, where he has been working mainly on QoS for resource-constrained real-time systems using stochastic optimization techniques. Currently, he is pursuing a Ph.D. degree at the Technische Universiteit Eindhoven.Liesbeth Steffens received her M.Sc. from Utrecht University (NL) in 1972. She spent most of her professional life in Philips Research in Eindhoven. She contributed to the design of a real-time distributed operating system, a video-on-demand server, a DVD player, a set-top box, and a QoS-based Resource-Management framework for streaming video. Her current focus is on characterization of resource requirements, resource reservation, and system-on-chip infrastructure.Wim F. J. Verhaegh received the mathematical engineering degree with honors in 1990 from the Technische Universiteit Eindhoven, The Netherlands. Since then, he is with the Philips Research Laboratories in Eindhoven, The Netherlands. From 1990 until 1998, he has been a member of the department Digital VLSI, where he has been working on high-level synthesis of DSP systems for video applications, with the emphasis on scheduling problems and techniques. Based on this work, he received a Ph.D. degree in 1995 from the Technische Universiteit Eindhoven. Since 1998, he is working on various optimization aspects of multimedia systems, networks, and applications. On the one hand, this concerns application-level resource management and scheduling, for optimization of quality of service of multimedia systems. On the other hand, this concerns adaptive algorithms and machine learning algorithms for user interaction issues, such as content filtering and automatic playlist generation.Reinder J. Bril received a B.Sc. and a M.Sc. (both with honors) from the Department of Electrical Engineering of the University of Twente, and a Ph.D. from the Technische Universiteit Eindhoven (TU/e), The Netherlands. He started his professional career at the Delft University of technology in the Department of Electrical Engineering. From May 1985 till August 2004, he has been with Philips. He has worked in both Philips Research as well as Philips Business Units, on various topics, including fault-tolerance, formal specifications, and software architecture analysis, and in different application domains. The last five years, he worked at Philips Research Laboratories Eindhoven (PRLE), the Netherlands, in the area of Quality of Service (QoS) for consumer devices, with a focus on dynamic resource management in receivers in broadcast environments (such as digital TV-sets and set-top boxes). In September 2004, he made a transfer to the Technische Universiteit Eindhoven (TU/e), Department of Mathematics and Computer Science, Group System Architecture and Networking (SAN), i.e. back to the academic world, after 19 years in industry.Christian Hentschel received his Dr.-Ing. (Ph.D.) in 1989 and Dr.-Ing. habil. in 1996 at the University of Technology in Braunschweig, Germany. He worked on digital video signal processing with focus on quality improvement. In 1995, he joined Philips Research in Briarcliff Manor, USA, where he headed a research project on moiré analysis and suppression for CRT based displays. In 1997, he moved to Philips Research in Eindhoven, The Netherlands, leading a cluster for Programmable Video Architectures. Later he held a position of a Principal Scientist and coordinated a project on scalable media processing with dynamic resource control between different research laboratories. In 2003, he became a full professor at the Brandenburg University of Technology in Cottbus, Germany. Currently he chairs the department of Media Technology. He is a member of the Technical Committee of the International Conference on Consumer Electronics (IEEE) and a member of the FKTG in Germany.     

ScaleSpaceViz: α-Scale spaces in practice

Kernels of the so-called α-scale space have the undesirable property of having no closed-form representation in the spatial domain, despite their simple closed-form expression in the Fourier domain. This obstructs spatial convolution or recursive implementation. For this reason an approximation of the 2D α-kernel in the spatial domain is presented using the well-known Gaussian kernel and the Poisson kernel. Experiments show good results, with maximum relative errors of less than 2.4%. The approximation has been successfully implemented in a program for visualizing α-scale spaces. Some examples of practical applications with scale space feature points using the proposed approximation are given. The text was submitted by the authors in English. Frans Kanters received his MSc degree in Electrical Engineering in 2002 from the Eindhoven University of Technology in the Netherlands. Currently he is working on his PhD at the Biomedical Imaging and Informatics group at the Eindhoven University of Technology. His PhD work is part of the “Deep Structure, Singularities, and Computer Vision (DSSCV)” project sponsored by the European Union. His research interests include scale space theory, image reconstruction, image processing algorithms, and hardware implementations thereof. Luc Florack received his MSc degree in theoretical physics in 1989 and his PhD degree cum laude in 1993 with a thesis on image structure, both from Utrecht University, the Netherlands. During the period from 1994 to 1995, he was an ERCIM/HCM research fellow at INRIA Sophia-Antipolis, France, and IN-ESC Aveiro, Portugal. In 1996 he was an assistant research professor at DIKU, Copenhagen, Denmark, on a grant from the Danish Research Council. From 1997 to June 2001, he was an assistant research professor at Utrecht University in the Department of Mathematics and Computer Science. Since June 1, 2001, he has been working as an assistant professor and, then, as an associate professor at Eindhoven University of Technology, Department of Biomedical Engineering. His interest includes all multiscale structural aspects of signals, images, and movies and their applications to imaging and vision. Remco Duits received his MSc degree (cum laude) in Mathematics in 2001 from the Eindhoven University of Technology, the Netherlands. Today he is a PhD student at the Department of Biomedical Engineering at the Eindhoven University of Technology on the subject of multiscale perceptual organization. His interest subtends functional analysis, group theory, partial differential equations, multiscale representations and their applications to biomedical imaging and vision, perceptual grouping. Currently, he is finishing his thesis “Perceptual Organization in Image Analysis (A Mathematical Approach Based on Scale, Orientation and Curvature).” During his PhD work, several of his submissions at conferences were chosen as selected or best papers—in particular, at the PRIA 2004 conference on pattern recognition and image analysis in St. Petersburg, where he received a best paper award (second place) for his work on invertible orientation scores. Bram Platel received his Masters Degree cum laude in biomedical engineering from the Eindhoven University of Technology in 2002. His research interests include image matching, scale space theory, catastrophe theory, and image-describing graph constructions. Currently he is working on his PhD in the Biomedical Imaging and Informatics group at the Eindhoven University of Technology. Bart M. ter Haar Romany is full professor in Biomedical Image Analysis at the Department of Biomedical Engineering at Eindhoven University of Technology. He has been in this position since 2001. He received a MSc in Applied Physics from Delft University of Technology in 1978, and a PhD on neuromuscular nonlinearities from Utrecht University in 1983. After being the principal physicist of the Utrecht University Hospital Radiology Department, in 1989 he joined the department of Medical Imaging at Utrecht University as an associate professor. His interests are mathematical aspects of visual perception, in particular linear and non-linear scale-space theory, computer vision applications, and all aspects of medical imaging. He is author of numerous papers and book chapters on these issues; he edited a book on non-linear diffusion theory and is author of an interactive tutorial book on scale-space theory in computer vision. He has initiated a number of international collaborations on these subjects. He is an active teacher in international courses, a senior member of IEEE, and IEEE Chapter Tutorial Speaker. He is chairman of the Dutch Biophysical Society.     

A formal approach to designing delay-insensitive circuits

Summary A method for designing delay-insensitive circuits is presented based on a simple formalism. The communication behavior of a circuit with its environment is specified by a regular expression-like program. Based on formal manipulations this program is then transformed into a delay-insensitive network of basic elements realizing the specified circuit. The notion of delay-insensitivity is concisely formalized. Jo C. Ebergen received his Master's degree in Mathematics from Eindhoven University of Technology in 1983. From 1983 until 1987 he has been working as a researcher at the Centre for Mathematics and Computer Science in Amsterdam in the area of VLSI design. In 1987, he received his Ph.D. degree from Eindhoven University of Technology. Currently, he is assistant professor at the University of Waterloo. His main research interests are programming methodology, parallel computations, and delay-insensitive circuit design. Dr. Ebergen is a member of ACM and EATCS.The research reported in this article was carried out while the author was working at CWI (Centre for Mathematics and Computer Science) in Amsterdam     

Controller Area Network (CAN) schedulability analysis: Refuted,revisited and revised

Controller Area Network (CAN) is used extensively in automotive applications, with in excess of 400 million CAN enabled microcontrollers manufactured each year. In 1994 schedulability analysis was developed for CAN, showing how worst-case response times of CAN messages could be calculated and hence guarantees provided that message response times would not exceed their deadlines. This seminal research has been cited in over 200 subsequent papers and transferred to industry in the form of commercial CAN schedulability analysis tools. These tools have been used by a large number of major automotive manufacturers in the design of in-vehicle networks for a wide range of cars, millions of which have been manufactured during the last decade. This paper shows that the original schedulability analysis given for CAN messages is flawed. It may provide guarantees for messages that will in fact miss their deadlines in the worst-case. This paper provides revised analysis resolving the problems with the original approach. Further, it highlights that the priority assignment policy, previously claimed to be optimal for CAN, is not in fact optimal and cites a method of obtaining an optimal priority ordering that is applicable to CAN. The paper discusses the possible impact on commercial CAN systems designed and developed using flawed schedulability analysis and makes recommendations for the revision of CAN schedulability analysis tools. Robert I. Davis received a DPhil in Computer Science from the University of York in 1995. Since then he has founded three start-up companies, all of which have succeeded in transferring real-time systems research into commercial product. At Northern Real-Time Technologies Ltd. (1995–1997) he was responsible for development of the Volcano CAN software library. At LiveDevices Ltd. (1997–2001) he was responsible for development of the Real-Time Architect suite of products, including an OSEK RTOS and schedulability analysis tools. In 2002, Robert returned to the University of York, and in 2004 he was involved in setting up a spin out company, Rapita Systems Ltd., aimed at transferring worst-case execution time analysis technology into industry. Robert is a member of the Real-Time Systems Research Group at the University of York, and a director of Rapita Systems Ltd. His research interests include scheduling algorithms and schedulability analysis for real-time systems. Alan Burns is head of the Real-Time Systems Research Group at the University of York. His research interests cover a number of aspects of real-time systems including the assessment of languages for use in the real-time domain, distributed operating systems, the formal specification of scheduling algorithms and implementation strategies, and the design of dependable user interfaces to real-time applications. He has authored/co-authored over 370 papers and 10 books, with a large proportion of them concentrating on real-time systems and the Ada programming language. Professor Burns has been actively involved in the creation of the Ravenscar Profile, a subset of Ada”s tasking model, designed to enable the analysis of real-time programs and their timing properties. Reinder J. Bril received a B.Sc. and an M.Sc. (both with honours) from the University of Twente, and a Ph.D. from the Technische Universiteit Eindhoven, the Netherlands. He started his professional career in January 1984 at the Delft University of Technology. From May 1985 until August 2004, he was with Philips, and worked in both Philips Research as well as Philips’ Business Units. He worked on various topics, including fault tolerance, formal specifications, software architecture analysis, and dynamic resource management, and in different application domains, e.g. high-volume electronics consumer products and (low volume) professional systems. In September 2004, he made a transfer back to the academic world, to the System Architecture and Networking (SAN) group of the Mathematics and Computer Science department of the Technische Universiteit Eindhoven. His main research interests are currently in the area of reservation-based resource management for networked embedded systems with real-time constraints. Johan J. Lukkien has been head of the System Architecture and Networking Research group at Eindhoven University of Technology since 2002. He received an M.Sc. and a Ph.D. from Groningen University in the Netherlands. In 1991, he joined Eindhoven University, after two years leave at the California Institute of Technology. His research interests include the design and performance analysis of parallel and distributed systems. Until 2000 he was involved in large-scale simulations in physics and chemistry. Since 2000, his research focus has shifted to the application domain of networked resource-constrained embedded systems. Contributions of the SAN group are in the area of component-based middleware for resource-constrained devices, distributed co-ordination, Quality of Service in networked systems and schedulability analysis in real-time systems.     

Robust H∞ Filter Design for 2D Discrete Systems in Roesser Model

This paper investigates the robust H∞ filtering problem for uncertain two-dimensional (2D) systems described by the Roesser model. The parameter uncertainties considered in this paper are assumed to be of polytopie type. A new structured polynomi-ally parameter-dependent method is utilized, which is based on homogeneous polynomially parameter-dependent matrices of arbitrary degree. The proposed method includes results in the quadratic framework and the linearly parameter-dependent framework as special cases for zeroth degree and first degree, respectively. A numerical example illustrates the feasibility and advantage of the proposed filter design methods.     

Using Catastrophe Theory to Derive Trees from Images

In order to investigate the deep structure of Gaussian scale space images, one needs to understand the behaviour of critical points under the influence of blurring. We show how the mathematical framework of catastrophe theory can be used to describe the different types of annihilations and the creation of pairs of critical points and how this knowledge can be exploited in a scale space hierarchy tree for the purpose of a topology based segmentation. A key role is played by scale space saddles and iso-intensity manifolds through them. We discuss the role of non-generic catastrophes and their influence on the tree and the segmentation. Furthermore it is discussed, based on the structure of iso-intensity manifolds, why creations of pairs of critical points don’t influence the tree. We clarify the theory with an artificial image and a simulated MR image.Arjan Kuijper received his M.Sc. degree in applied mathematics in 1995 with a thesis on the comparision of two image restoration techniques, from the University of Twente, The Netherlands. During the period 1996–1997 he worked at ELTRA Parkeergroep, Ede, The Netherlands. In the period 1997-2002 he has been a Ph.D. student and associate researcher at the Institute of Information and Computing Sciences of Utrecht University. In 2002 he received his Ph.D. degree with a thesis on “Deep Structure of Gaussian Scale Space Images” and worked as postdoc at Utrecht University on the project “Co-registration of 3D Images” on a grant of the Netherlands Ministry of Economic Affairs within the framework of the Innovation Oriented Research Programme. Since Januari 1st 2003 he has been working as an assistant research professor at the IT University of Copenhagen in Denmark funded by the IST Programme “Deep Structure, Singularities, and Computer Vision (DSSCV)” of the European Union. His interest subtends all mathematical aspects of image analysis, notably multiscale representations (scale spaces), catastrophe and singularity theory, medial axes and symmetry sets, and applications to medical imaging.Luc M.J. Florack received his M.Sc. degree in theoretical physics invv 1989, and his Ph.D. degree in 1993 with a thesis on image structure, both from Utrecht University, The Netherlands. During the period 1994–1995 he was an ERCIM/HCM research fellow at INRIA Sophia-Antipolis, France, and INESC Aveiro, Portugal. In 1996 he was an assistant research professor at DIKU, Copenhagen, Denmark, on a grant from the Danish Research Council. From 1997 until June 2001 he was an assistant research professor at Utrecht University at the Department of Mathematics and Computer Science. Since June 1st 2001 he is with Eindhoven University of Technology, Department of Biomedical Engineering, currenlty employed as an associate professor. His interest subtends all structural aspects of signals, images and movies, notably multiscale representations, and their applications to imaging and vision.     

Handling non-canonical software requirements based on Annotated Predicate Calculus

Eliciting requirements for a proposed system inevitably involves the problem of handling undesirable information about customer's needs, including inconsistency, vagueness, redundancy, or incompleteness. We term the requirements statements involved in the undesirable information non-canonical software requirements. In this paper, we propose an approach to handling non-canonical software requirements based on Annotated Predicate Calculus (APC). Informally, by defining a special belief lattice appropriate for representing the stakeholder's belief in requirements statements, we construct a new form of APC to formalize requirements specifications. We then show how the APC can be employed to characterize non-canonical requirements. Finally, we show how the approach can be used to handle non-canonical requirements through a case study. Kedian Mu received B.Sc. degree in applied mathematics from Beijing Institute of Technology, Beijing, China, in 1997, M.Sc. degree in probability and mathematical statistics from Beijing Institute of Technology, Beijing, China, in 2000, and Ph.D. in applied mathematics from Peking University, Beijing, China, in 2003. From 2003 to 2005, he was a postdoctoral researcher at Institute of Computing Technology, Chinese Academy of Sciences, China. He is currently an assistant professor at School of Mathematical Sciences, Peking University, Beijing, China. His research interests include uncertain reasoning in artificial intelligence, knowledge engineering and science, and requirements engineering. Zhi Jin was awarded B.Sc. in computer science from Zhejiang University, Hangzhou, China, in 1984, and studied for her M.Sc. in computer science (expert system) and her Ph.D. in computer science (artificial intelligence) at National Defence University of Technology, Changsha, China. She was awarded Ph.D. in 1992. She is a senior member of China Computer Federation. She is currently a professor at Academy of Mathematics and System Sciences, Chinese Academy of Science. Her research interests include knowledge-based systems, artificial intelligence, requirements engineering, ontology engineering, etc. Her current research focuses on ontology-based requirements elicitation and analysis. She has got about 60 papers published, including co-authoring one book. Ruqian Lu is a professor of computer science of the Institute of Mathematics, Chinese Academy of Sciences. His research interests include artificial intelligence, knowledge engineering and knowledge based software engineering. He designed the “Tian Ma” software systems that have been widely applied in more than 20 fields, including the national defense and the economy. He has won two first class awards from Chinese Academy of Sciences and a National second class prize from the Ministry of Science and Technology. He has also won the sixth Hua Lookeng Prize for Mathematics. Yan Peng received B.Sc. degree in software from Jilin University, Changchun, China, in 1992. From June 2002 to December 2005, he studied for his M.E. in software engineering at College of Software Engineering, Graduate School of Chinese Academy of Sciences, Beijing, China. He was awarded M.E degree in 2006. He is currently responsible for CRM (customer relationship management) and BI (business intelligence) project in the BONG. His research interests include customer relationship management, business intelligence, data ming, software engineering and requirements engineering.     

A multimodal virtual reality interface for 3D interaction with VTK

The object-oriented visualization Toolkit (VTK) is widely used for scientific visualization. VTK is a visualization library that provides a large number of functions for presenting three-dimensional data. Interaction with the visualized data is controlled with two-dimensional input devices, such as mouse and keyboard. Support for real three-dimensional and multimodal input is non-existent. This paper describes VR-VTK: a multimodal interface to VTK on a virtual environment. Six degree of freedom input devices are used for spatial 3D interaction. They control the 3D widgets that are used to interact with the visualized data. Head tracking is used for camera control. Pedals are used for clutching. Speech input is used for application commands and system control. To address several problems specific for spatial 3D interaction, a number of additional features, such as more complex interaction methods and enhanced depth perception, are discussed. Furthermore, the need for multimodal input to support interaction with the visualization is shown. Two existing VTK applications are ported using VR-VTK to run in a desktop virtual reality system. Informal user experiences are presented. Arjan J. F. Kok is an assistant professor at the Department of Computer Science at the Open University of the Netherlands. He studied Computer Science at the Delft University of Technology, The Netherlands. He received his Ph.D. from the same university. He worked as a Scientist for TNO (Netherlands Organization for Applied Scientific Research) and as assistant professor at the Eindhoven University of Technology before he joined the Open University. His research interests are visualization, virtual reality, and computer graphics. Robert van Liere studied Computer Science at the Delft University of Technology, the Netherlands. He received his Ph.D. with the thesis “Studies in Interactive Scientific Visualization” at the University of Amsterdam. Since 1985, he has worked at CWI, the Center for Mathematics and Computer Science in Amsterdam in which he is the head of CWI’s visualization research group. Since 2004, he holds a part-time position as full professor at the Eindhoven University of Technology. His research interests are in interactive data visualization and virtual reality. He is a member of IEEE.     

Anti-counterfeiting, key distribution, and key storage in an ambient world via physical unclonable functions

Virtually all applications which provide or require a security service need a secret key. In an ambient world, where (potentially) sensitive information is continually being gathered about us, it is critical that those keys be both securely deployed and safeguarded from compromise. In this paper, we provide solutions for secure key deployment and storage of keys in sensor networks and radio frequency identification systems based on the use of Physical Unclonable Functions (PUFs). In addition, to providing an overview of different existing PUF realizations, we introduce a PUF realization aimed at ultra-low cost applications. We then show how the properties of Fuzzy Extractors or Helper Data algorithms can be used to securely deploy secret keys to a low cost wireless node. Our protocols are more efficient (round complexity) and allow for lower costs compared to previously proposed ones. We also provide an overview of PUF applications aimed at solving the counterfeiting of goods and devices.

Invertible orientation scores as an application of generalized wavelet theory

Inspired by the visual system of many mammals, we consider the construction of—and reconstruction from—an orientation score of an image, via a wavelet transform corresponding to the left-regular representation of the Euclidean motion group in (ℝ²) and oriented wavelet φ ∈ (ℝ²). Because this representation is reducible, the general wavelet reconstruction theorem does not apply. By means of reproducing kernel theory, we formulate a new and more general wavelet theory, which is applied to our specific case. As a result we can quantify the well-posedness of the reconstruction given the wavelet φ and deal with the question of which oriented wavelet φ is practically desirable in the sense that it both allows a stable reconstruction and a proper detection of local elongated structures. This enables image enhancement by means of left-invariant operators on orientation scores. The text was submitted by the authors in English. Remco Duits received his M.Sc. degree (cum laude) in Mathematics in 2001 from Eindhoven University of Technology, The Netherlands. He received his PhD degree (cum laude) at the Department of Biomedical Engineering at Eindhoven University of Technology on the subject of multiscale perceptual organization. His interests include functional analysis, group theory, partial differential equations, multiscale representations and their applications to biomedical imaging and vision, and perceptual grouping. His PhD thesis is titled Perceptual Organization in Image Analysis (A Mathematical Approach Based on Scale, Orientation and Curvature). Several of his submissions at conferences have been selected/best papers, in particular, at the PRIA 2004 conference on pattern recognition and image analysis in St. Petersburg, he received a best paper award (second prize) for his work on invertible orientation scores. Currently, he is working at Eindhoven University of Technology as an assistant professor at both the Department of Applied Mathematics and Computer Science and the Department of Biomedical Engineering. Maurice Duits received his MSc degree (cum laude) in Mathematics in 2004 from Eindhoven University of Technology, The Netherlands on the subject of reproducing kernels in frame and wavelet transforms. Now he is a PhD student at the Department of Mathematics at Katholieke Universiteit Leuven on the subject of random matrices. His interests include Riemann-Hilbert problems, random matrices, orthogonal polynomials and Toeplitz matrices. Markus van Almsick earned a master degree in physics at the Technical University of Munich in 1990. From 1988 until 1992, he worked for the University of Illinois at Urbana-Champaign as a research and teaching associate. He taught undergraduate chemistry as well as graduate courses in advanced quantum mechanics, for which he developed Mathematica course material. His research interest has been quantum logic and quantization procedures of space-time. Since 1990, he has been a freelance applications consultant for Wolfram Research, Inc., USA, and Wolfram Research Europe Ltd., United Kingdom, promoting Mathematica at universities and research institutions in the U.S., Europe, and Israel, as well as developing Mathematica packages and application material. In 1996, Mr. van Almsick joined the Max Planck Insitut fur Biophysik in Frankfurt am Main, Germany, where he addressed problems in nonequilibrium thermodynamics until the theoretical department closed in 1997. Then, until 2001 he worked in collaboration with QT Software GmbH, Munich, as a full-time Mathematica consultant on a wide variety of assignments, e.g., designing the geometry of slides for playgrounds, modeling human interaction via graph theory (“social networks”), lossless image compression, vibration control in electric engines, and the isomer enumeration of libraries containing chemical diamutamers. Since 2001, he has been a part-time employee of the Technische Universiteit Eindhoven, where he develops Math VisionTools, a biomedical image analysis toolkit based on Mathematica. Bart M. ter Haar Romany is full professor in Biomedical Image Analysis at the Department of Biomedical Engineering at Eindhoven University of Technology. He has been in this position since 2001. He received a MSc in Applied Physics from Delft University of Technology in 1978, and a PhD on neuromuscular nonlinearities from Utrecht University in 1983. After being the principal physicist of the Utrecht University Hospital Radiology Department, in 1989 he joined the department of Medical Imaging at Utrecht University as an associate professor. His interests are mathematical aspects of visual perception, in particular linear and non-linear scale-space theory, computer vision applications, and all aspects of medical imaging. He is author of numerous papers and book chapters on these issues; he edited a book on non-linear diffusion theory and is author of an interactive tutorial book on scale-space theory in computer vision. He has initiated a number of international collaborations on these subjects. He is an active teacher in international courses, a senior member of IEEE, and IEEE Chapter Tutorial Speaker. He is chairman of the Dutch Biophysical Society. An erratum to this article is available at .     

Program transformation system based on generalized partial computation

Generalized Partial Computation (GPC) is a program transformation method utilizing partial information about input data, abstract data types of auxiliary functions and the logical structure of a source program. GPC uses both an inference engine such as a theorem prover and a classical partial evaluator to optimize programs. Therefore, GPC is more powerful than classical partial evaluators but harder to implement and control. We have implemented an experimental GPC system called WSDFU (Waseda Simplify-Distribute-Fold-Unfold). This paper demonstrates the power of the program transformation system as well as its theorem prover and discusses some future works. Yoshihiko Futamura, Ph.D.: He is Professor of Department of Information and Computer Science and the director of the Institute for Software Production Technology (ISPT) of Waseda University. He received his BS in mathematics from Hokkaido University in 1965, MS in applied mathematics from Harvard University in 1972 and Ph.D. degree from Hokkaido University in 1985. He joined Hitachi Central Research Laboratory in 1965 and moved to Waseda University in 1991. He was a visiting professor of Uppsala University from 1985 to 1986 and a visiting scholar of Harvard University from 1988 to 1989. Automatic generation of computer programs and programming methodology are his main research fields. He is the inventor of the Futamura Projections in partial evaluation and ISO8631 PAD (Problem Analysis Diagram). Zenjiro Konishi: He is a visiting lecturer of Institute for Software Production Technology, Waseda University. He received his M. Sc. degree in mathematics from Waseda University in 1995. His research interests include automated theorem proving. He received JSSST Takahashi Award in 2001. He is a member of JSSST and IPSJ. Robert Glück, Ph.D., Habil.: He is an Associate Professor of Computer Science at the University of Copenhagen. He received his Ph.D. and Habilitation (venia docendi) from the Vienna University of Technology in 1991 and 1997. He was research assistant at the City University of New York and received twice the Erwin-Schrodinger-Fellowship of the Austrian Science Foundation (FWF). After being an Invited Fellow of the Japan Society for the Promotion of Science (JSPS), he is now funded by the PRESTO21 program for basic research of the Japan Science and Technology Corporation (JST) and located at Waseda University in Tokyo. His main research interests are advanced programming languages, theory and practice of program transformation, and metaprogramming.     

A new type of solution method for the generalized linear complementarity problem over a polyhedral cone

This paper addresses the generalized linear complementarity problem （GLCP） over a polyhedral cone. To solve the problem, we first equivalently convert the problem into an affine variational inequalities problem over a closed polyhedral cone, and then propose a new type of method to solve the GLCP based on the error bound estimation. The global and R-linear convergence rate is established. The numerical experiments show the efficiency of the method.     

A new method of embedded fourth order with four stages to study raster CNN simulation

A new Runge-Kutta （PK） fourth order with four stages embedded method with error control is presentea m this paper for raster simulation in cellular neural network （CNN） environment. Through versatile algorithm, single layer/raster CNN array is implemented by incorporating the proposed technique. Simulation results have been obtained, and comparison has also been carried out to show the efficiency of the proposed numerical integration algorithm. The analytic expressions for local truncation error and global truncation error are derived. It is seen that the RK-embedded root mean square outperforms the RK-embedded Heronian mean and RK-embedded harmonic mean.     

Bounded time-stamps

Summary Time-stamps are labels which a system adds to its data items. These labels enable the system to keep track of the temporal precedence relations among its data elements. Many distributed protocols and some applications use the natural numbers as time-stamps. The natural numbers however are not useful for bounded protocols. In this paper we develop a theory ofbounded time-stamps. Time-stamp schemes are defined and the complexity of their implementation is analyzed. This indicates a direction for developing a general tool for converting time-stamp based protocols to bounded protocols. Amos Israeli received his B.Sc. in Mathematics and Physics from Hebrew University in 1976, and his M.Sc. and D.Sc. in Computer Science from the Weizmann Institute in 1980 and the Technion in 1985, respectively. Currently he is a senior lecturer at the Tlectrical Engineering Department at the Technion. Prior to this he was a postdoctoral fellow at the Aiken Computation Laboratory at Harvard. His research interests are in Parallel and Distributed Computing and in Robotics. In particular he has worked on the design and analysis of Wait-Free and Self-Stabilizing distributed protocols. Ming Li received his M.S. and Ph.D. in Computer Science from Wayne State University in 1980 and Cornell University 1985, respectively. Currently he is an associate professor at the Computer Science Department at the University of Waterloo. His research interests are in Theory of Computing, Kolmogorov Complexity, and Machine Learning.Supported in part by the Weizmann fellowship and NSF Grant DCR-86-00379Supported in part by ONR Grant N00014-85-k-0445 and Army Research Office Grant DAAL03-86-K-0171 at Harvard University, by NSF Grant kDCR-86-06366 at Ohio State University, and by NSERC Operating Grant OGP0036747. Most of this work was done when the authors were at Aiken Computation Laboratory at Harvard University. The authors also acknowledge the hospitality of the computer science department at York University, Canada     

Enhanced H∞ Filtering for Continuous-time State-delayed Systems

The H∞ filtering problem for continuous-time polytopic uncertain time-delay systems is investigated. Attention is focused on the design of full-order filters guaranteeing a prescribed H∞ attenuation level for the filtering error system. First, a simple alternative proof is given for an improved linear matrix inequality （LMI） representation of H∞ performance. Then, based on the performance criterion which keeps Lyapunov matrices out of the product of system dynamic matrices, a suficient condition for the existence of robust estimators is formulated in terms of LMIs, and the corresponding filter design is cast into a convex optimization problem which can be effciently handled by using standard numerical algorithms. It is shown that the proposed design strategy allows the use of parameter-dependent Lyapunov functions and hence it is less conservative than some earlier results. A numerical example is employed to demonstrate the feasibility and advantage of the proposed design.     

Node similarity in the citation graph

Published scientific articles are linked together into a graph, the citation graph, through their citations. This paper explores the notion of similarity based on connectivity alone, and proposes several algorithms to quantify it. Our metrics take advantage of the local neighborhoods of the nodes in the citation graph. Two variants of link-based similarity estimation between two nodes are described, one based on the separate local neighborhoods of the nodes, and another based on the joint local neighborhood expanded from both nodes at the same time. The algorithms are implemented and evaluated on a subgraph of the citation graph of computer science in a retrieval context. The results are compared with text-based similarity, and demonstrate the complementarity of link-based and text-based retrieval. Wangzhong Lu holds a Bachelor's degree from Hefei University of Technology (1993), and a Master's degree from Dalhousie University (2001), both in computer science. From 1993 to 1999 he worked as a developer with China National Computer Software and Technical Service Corp. in Beijing. From 2001 to 2005 he held industrial positions as a senior software architect in Atlantic Canada. He is currently with DST Systems, Charlotte, NC, as a senior data architect. Jeannette Janssen's research area is applied graph theory. She has worked on the problem of frequency assignment in cellular and digital broadcasting networks. Her current interest is in graph theory applied to the World Wide Web and other networked information spaces. Dr. Janssen did her Master's studies at Eindhoven University of Technology in the Netherlands, and her doctorate at Lehigh University, USA. She is currently an associate professor at Dalhousie University, Canada. Evangelos Milios received a diploma in electrical engineering from the National Technical University of Athens, and Master's and Ph.D. degrees in electrical engineering and computer science from the Massachusetts Institute of Technology. He held faculty positions at the University of Toronto and York University. He is currently a professor of computer science at Dalhousie University, Canada, where he was Director of the Graduate Program. He has served on the committees of the ACM Dissertation Award, and the AAAI/SIGART Doctoral Consortium. He has worked on the interpretation of visual and range signals for landmark-based positioning, navigation and map construction in single- and multi-agent robotics. His current research activity is centered on Networked Information Spaces, Web information retrieval, and aquatic robotics. He is a senior member of the IEEE. Nathalie Japkowicz is an associate professor at the School of Information Technology and Engineering of the University of Ottawa. She obtained her Ph.D. from Rutgers University, her M.Sc. from the University of Toronto, and her B.Sc. from McGill University. Prior to joining the University of Ottawa, she taught at Ohio State University and Dalhousie University. Her area of specialization is Machine Learning and her most recent research interests focused on the class imbalance problem. She made over 50 contributions in the form of journal articles, conference articles, workshop articles, magazine articles, technical reports or edited volumes. Yongzheng Zhang obtained a B.E. in computer applications from Southeast University, China, in 1997 and a M.S. in computer science from Dalhousie University in 2002. From 1997 to 1999 he was an instructor and undergraduate advisor at Southeast University. He also worked as a software engineer in Ricom Information and Telecommunications Co. Ltd., China. He is currently a Ph.D. candidate at Dalhousie University. His research interests are in the areas of Information Retrieval, Machine Learning, Natural Language Processing, and Web Mining, particularly centered on Web Document Summarization. A paper based on his Master's thesis received the best paper award at the 2003 Canadian Artificial Intelligence conference.     

Robust Quality Adaptation for Internet Video Streaming

Internet video streaming is a widely popular application however, in many cases, congestion control facilities are not well integrated into such applications. In order to be fair to other users that do not stream video, rate adaptation should be performed to respond to congestion. On the other hand, the effect of rate adaptation on the viewer should be minimized and this extra mechanism should not overload the client and the server. In this paper, we develop a heuristic approach for unicast congestion control. The primary feature of our approach is the two level adaptation algorithm that utilizes packet loss rate as well as receiver buffer data to maintain satisfactory buffer levels at the receiver. This is particularly important if receiver has limited buffer such as in mobile devices. When there is no congestion, to maintain best buffer levels, fine grain adjustments are carried out at the packet level. Depending on the level of congestion and receiver buffer level, rate shaping that involves frame discard and finally rate adaptation by switching to a different pre-encoded video stream are carried out. Additive increase multiplicative decrease policy is maintained to respond to congestion in a TCP- friendly manner. The algorithm is implemented and performance results show that it has adaptation ability that is suitable for both local area and wide area networks. E. Turhan Tunali received B.Sc. Degree in Electrical Engineering from Middle East Technical University and M.Sc. Degree in Applied Statistics from Ege University, both in Turkey. He then received D.Sc. Degree in Systems Science and Mathematics from Washington University in St. Louis, U.S.A. in 1985. After his doctorate study, he joined Computer Engineering Department of Ege University as an assistant professor where he became an associate professor in 1988. During the period of 1992–1994, he worked in Department of Computer Technology of Nanyang Technological University of Singapore as a Visiting Senior Fellow. He then joined International Computer Institute of Ege University as a Professor where he is currently the director. In the period of 2000–2001 he worked in Department of Computer Science of Loyola University of Chicago as a Visiting Professor. His current research interests include adaptive video streaming and Internet performance measurements. Dr. Tunali is married with an eighteen year old son. Aylin Kantarci received B.Sc., M.Sc. and Ph.D. degrees all from Computer Engineering Department of Ege University, Izmir, Turkey, in 1992, 1994 and 2000, respectively. She then joined the same department as an assistant professor. Her current research interests include adaptive video streaming, video coding, operating systems, multimedia systems and distributed systems. Nukhet Ozbek received B.Sc. degree in Electrical and Electronics Engineering from School of Engineering and M.Sc. degree in Computer Science from International Computer Institute both in Ege University, Izmir, Turkey. From 1998 to 2003 she worked in the DVB team of Digital R&D at Vestel Corporation, Izmir-Turkey that produces telecommunication and consumer electronics devices. She is currently a Ph.D. student and a research assistant at International Computer Institute of Ege University. Her research areas include video coding and streaming, multimedia systems and set top box architectures.     

Synchronization and exponential estimates of complex networks with mixed time-varying coupling delays

Exponential estimates and sufficient conditions for the exponential synchronization of complex dynamical networks with bounded time-varying delays are given in terms of linear matrix inequalities （LMIs）. A generalized complex networks model involving both neutral delays and retarded ones is presented. The exponential synchronization problem of the complex networks is converted equivalently into the exponential stability problem of a group of uncorrelated delay functional differential equations with mixed timevarying delays. By utilizing the free weighting matrix technique, a less conservative delay-dependent synchronization criterion is derived. An illustrative example is provided to demonstrate the effectiveness of the proposed method.