ppxscal/embedding_network huggingface dataset:
A New Approach to Numerical Algorithms in Terms of Integrable Systems
Authors: Yoshimasa Nakamura
Venue: Proceedings of the International Conference on Informatics Research for Development of Knowledge Society Infrastructure (2004)

Almost four decades passed after the discovery of solitonsand infinite dimensional integrable systems. The theoryof integrable systems has had great impact to wide areain physics and mathematics. In this paper an approach tonumerical algorithms in terms of integrable systems is surveyed.Some integrable systems of Lax form describe continuousflows of efficient numerical algorithms, for example,the QR algorithm and the Jacobi algorithm. Discretizationsof integrable systems in tau-function level enable usto formulate algorithms for computing continued fractionssuch as the qd algorithm and the discrete Schur flow. Anew singular value decomposition (I-SVD) algorithm is designedby using a discrete integrable system defined by theChristoffel-Darboux identity for orthogonal polynomials.
Transaction Policies for Mobile Networks
Venue: Proceedings of the Fifth IEEE International Workshop on Policies for Distributed Systems and Networks (2004)

Advances in wireless technology and affordable info-appliancesare making mobile computing a reality. Suchappliances can both communicate with a fixed station orwith other info-appliances in an ad-hoc manner. In bothscenarios the transaction paradigm is vital to provide applicationswith consistent access to durable data.However, current mobile transactional systems fail toprovide the so much needed adaptability to the large set ofusage scenarios and applications semantics (e.g. disconnectedwork, relaxed ACID properties, etc.).We present a transactional object-based mobile system,called MobileTrans, that supports the definition and enforcementof transaction policies. Such policies are separatedfrom the application code and specify transactionsbehavior: (1) how data is fetched, (2) how updates areperformed, (3) the degrees of consistency and atomicity required.Transaction policies can be either declarative (e.g.XML) or programmatic (e.g. Java, C#).
Computational Logic in Multi-Agent Systems: Recent Advances and Future Directions
Authors: Paolo Torroni
Venue: Annals of Mathematics and Artificial Intelligence (2004)

Starting from the early days of multi-agent systems research, considerable effort has been devoted to giving formal foundations to agent technologies. Work done in this direction, based on computational logic, is an attempt to bridge an existing gap, between theoretical frameworks and their practical implementations. In the last two editions of the workshop on Computational Logic in Multi-Agent Systems, CLIMA'01 and CLIMA'02, two discussion panels have been organized, aimed at bringing researchers together and exchanging ideas on a number of topics. In this article, we elaborate on the outcome of such panels, to draw some considerations about the recent advances and future directions of Computational Logic in Multi-Agent Systems.
A real-time microprocessor debugging technique
Authors: Charles R. Hill
Venue: ACM SIGPLAN Notices (1983)

This note describes RED, a remotely executed debugger capable of generating a real-time source level trace history of a high level language program executing on a microprocessor. The trace history consists of a display of the source statements of each basic block executed, annotated by the time at which execution of that block began. Basic blocks are traced rather than statements to reduce sampling bandwidth requirements while still retaining the ability to record the essential logical flow of programs. RED is intended to assist in debugging stand-alone high level language process control programs with real-time constraints. We outline two possible implementation schemes for generating the real-time trace history. In both, a "debugging co-processor" collects in a history buffer the values of the program counter (PC) and the corresponding value of a clock as each basic block begins execution. The debugger, which runs on the processor hosting the compiler and has access to the co-processor over a fast link, reconstructs a source level trace from the PC-time pairs in the history buffer. In one scheme, the language compiler emits an extra instruction at the beginning of each basic block in the program to output the value of the program counter to a parallel port connected to the debug processor. The second method makes use of an extended target memory space to provide tag bits denoting basic blocks. When an instruction is fetched, the debug processor detects the presence of the tag bits and buffers up the value of the corresponding program counter and time. The first method is simpler to implement, requiring only conventional, usually straightforward hardware additions to the target, but requires the execution overhead of the extra instructions. In both cases the debugger itself runs on the host processor and has access to tables generated during compile time of the source program.
Disseminating Dynamic Data with QoS Guarantee in a Wide Area Network: A Practical Control Theoretic Approach
Venue: Proceedings of the 10th IEEE Real-Time and Embedded Technology and Applications Symposium (2004)

Often, data used in on-line decision making (for example,in determining how to react to changes in processbehavior, traffic flow control, etc.) is dynamic in natureand hence the timeliness of the data delivered to the decisionmaking process becomes very important. The delivereddata must conform to certain time or value basedapplication specific consistency requirements. The designof mechanisms for such data delivery is challenging giventhat dynamic data changes rapidly and unpredictably, thelatter making it very hard to use simple prediction techniques.To address these challenges we develop mechanismsto obtain timely and consistency-preserving updatesfor dynamic data by pulling data from the source at strategicallychosen points in time, providing Quality of Service(QoS) Guarantees. Motivated by the need for practical systemdesign, but using formal analytical techniques, we offera systematic approach based on control-theoretic principles.We present a stochastic controller based on the LinearQuadratic Gaussian (LQG) technique as a means fordeciding when to next refresh data from a source. A simpleenhancement of the LQG algorithm allows us to provideQoS guarantees. Using real-world traces of real-time datawe show the superior performance of our feedback-drivencontrol-theoretic approach by comparing with a previouslyproposed adaptive refresh technique, a pattern matchingtechnique, and a proportional controller with dynamicallychanging tuning criteria.
Global robust output feedback tracking control of robot manipulators
Authors: W. E. Dixon, E. Zergeroglu, D. M. Dawson
Venue: Robotica (2004)

This paper addresses the problem of global output feedback, link position tracking control of robot manipulators. Specifically, a robust, Lyapunov-based controller is designed to ensure that the link position tracking error is globally uniformly ultimately bounded despite the fact that only link position measurements are available in the presence of incomplete model information (i.e., parametric uncertainty and additive bounded disturbances).
A photorealistic predictive display
Authors: Tim Burkert Jan Leupold, Georg Passig
Venue: Presence: Teleoperators and Virtual Environments (2004)

The quality of a teleoperation system is decreased by time delays in the communication channel. Delays as low as a few hundred milliseconds between commanding an action and getting the visual feedback reduce the operator's performance. Predictive displays have proven their suitability to compensate for these delays, but at the expense of image quality when using computer-generated images. A photorealistic predictive display is presented that closes the feedback loop locally at the operator's side of a telepresence system. Photorealism is achieved using delayed camera images for texturing the predicted scene. Consumer graphics hardware is not only used for rendering but also for hardware-accelerated texture extraction. To allow concurrent access to model data, a multibuffer model structure is presented. A model or the teleoperator's environment is automatically acquired and updated by image processing techniques using a stereo camera as the only sensor.
ε-connections of abstract description systems
Authors: Oliver Kutz, Carsten Lutz, Frank Wolter, Michael Zakharyaschev
Venue: Artificial Intelligence (2004)

Combining knowledge representation and reasoning formalisms is an important and challenging task. It is important because non-trivial AI applications often comprise different aspects of the world, thus requiring suitable combinations of available formalisms modeling each of these aspects. It is challenging because the computational behavior of the resulting hybrids is often much worse than the behavior of their components.In this paper, we propose a new combination method which is computationally robust in the sense that the combination of decidable formalisms is again decidable, and which, nonetheless, allows non-trivial interactions between the combined components.The new method, called ε-connection, is defined in terms of abstract description systems (ADSs), a common generalization of description logics, many logics of time and space, as well as modal and epistemic logics. The basic idea of ε-connections is that the interpretation domains of n combined systems are disjoint, and that these domains are connected by means of n-ary 'link relations'. We define several natural variants of ε-connections and study in-depth the transfer of decidability from the component systems to their ε-connections.
Past is for free: on the complexity of verifying linear temporal properties with past
Authors: Nicolas Markey
Venue: Acta Informatica (2004)

We study the complexity of satisfiability and model checking problems for fragments of linear-time temporal logic with past (PLTL). We consider many fragments of PLTL, obtained by restricting the set of allowed temporal modalities, the use of negations or the nesting of future formulas into past formulas. Our results strengthen the widely accepted fact that &#x201c;past is for free&#x201d;, in the sense that allowing symmetric past-time modalities does not bring additional theoretical complexity. This result holds even for small fragments and even when nesting future formulas into past formulas.
Fixed Access Network Technologies
Authors: A. F. Cameron, D. J. Thorne, K. T. Foster, S. I. Fisher
Venue: BT Technology Journal (2004)

Telecommunications operators around the world are facing flat or declining revenues in their traditional services and expanding commercial and political demand for ubiquitous broadband access. This creates two opposing pressures &mdash; to cut costs radically and to invest heavily in new technology. The traditional fixed access network is central to both of these issues and this paper describes the technology that is being developed to meet these challenges.
On-line restricted caching
Authors: Mark Brehob, Richard Enbody, Eric Torng, Stephen Wagner
Venue: Journal of Scheduling (2003)

We study the on-line caching problem in a restricted cache where each memory item can be placed in only a restricted subset of cache locations. Examples of restricted caches in practice include victim caches, assist caches, and skew caches. To the best of our knowledge, all previous on-line caching studies have considered on-line caching in identical or fully-associative caches where every memory item can be placed in any cache location.In this paper, we focus on companion caches, a simple restricted cache that includes victim caches and assist caches as special cases. Our results show that restricted caches are significantly more complex than identical caches. For example, we show that the commonly studied Least Recently Used algorithm is not competitive unless cache reorganization is allowed while the performance of the First In First Out algorithm is competitive but not optimal. We also present two near optimal algorithms for this problem as well as lower bound arguments.
Power-aware compilation for register file energy reduction
Authors: José L. Ayala, Alexander Veidenbaum, Marisa López-Vallejo
Venue: International Journal of Parallel Programming (2003)

Most power reduction techniques have focused on gating the clock to unused functional units to minimize static power consumption, while system level optimizations have been used to deal with dynamic power consumption. Once these techniques are applied, register file power consumption becomes a dominant factor in the processor. This paper proposes a power-aware reconfiguration mechanism in the register file driven by a compiler. Optimal usage of the register file in terms of size is achieved and unused registers are put into a low-power state. Total energy consumption in the register file is reduced by 65% with no appreciable performance penalty for MiBench benchmarks on an embedded processor. The effect of reconfiguration granularity on energy savings is also analyzed, and the compiler approach to optimize energy results is presented.
Task migration in n-dimensional wormhole-routed mesh multicomputers
Authors: Gwo-Jong Yu, Chih-Yung Chang, Tzung-Shi Chen
Venue: Journal of Systems Architecture: the EUROMICRO Journal (2004)

In a mesh multicomputer, performing jobs needs to schedule submeshes according to some processor allocation scheme. In order to assign the incoming jobs to a free submesh, a task compaction scheme is needed to generate a larger contiguous free region. The overhead of compaction depends on the efficiency of the task migration scheme. In this paper, two simple task migration schemes are first proposed in n-dimensional mesh multicomputers with supporting dimension-ordered wormhole routing in one-port communication model. Then, a hybrid scheme which combines advantages of the two schemes is discussed. Finally, we evaluate the performance of all of these proposed approaches.
One-Staged Wormhole Routing for Irregular Faulty Patterns in Meshes
Authors: Ming-Jer Tsai
Venue: Proceedings of the Parallel and Distributed Systems, Tenth International Conference (2004)

A fault-tolerant wormhole routing algorithm in meshmulticomputer is proposed, which enables two good nodesto exchange their messages, except that there is no routingpath between them, in one stage without aid of global information.In the method, faulty nodes are enclosed with faultyblocks. And, a message is routed to reach the destination orgo out of the faulty block via multiple pre-established intermediatenodes if it is on the inside of a faulty block. A messagenot on the inside of a faulty block is routed toward thedestination till it encounters the faulty block enclosing thedestination, and is then routed toward the intermediate nodewhich is able to instruct it to go into the faulty block. Routingalgorithm RFB which permits the change of the routingdirection is designed for the message not on the insideof a faulty block, which makes it possible that the messagereaches the intermediate node in one stage. In our method,each channel is required to be split into two virtual ones.
Improvement of Compiled Instruction Set Simulator by Increasing Flexibility and Reducing Compile Time
Authors: Moo-Kyoung Chung, Chong-Min Kyung
Venue: Proceedings of the 15th IEEE International Workshop on Rapid System Prototyping (2004)

Although static compiled instruction set simulators(ISSs) are much faster than the interpretive ISSs, theyare barely used owing to the restrictions on flexibilityand compile time overhead. In this paper, we presentnew techniques that reduce the compile time overheadand increase the flexibility of the static compiled ISSwhile keeping the advantages of the static compiledsimulation. We remarkably reduce the compile andrecompilation time using object format instead of binaryformat as simulator input. "Dynamic BranchHandler" solves the indirect branch problem withoutloss of simulation speed, and "Dynamic Code Handler"enables to handle the dynamic code whose contentsare determined at run-time. We implement thosesolutions in OBSIM, which is cycle-accurate staticcompiled ISS. OBSIM is able to perform the simulationat a speed of up to 50 millions of simulated instructionsper second on Xeon 2GHz processor. We alsoachieve about nine times faster recompilation speedthan the corresponding static compiled ISS for the embeddedsoftware whose code consists of 18 files and199K lines of total C code.
Canonical abstraction for outerjoin optimization
Authors: Jun Rao, Hamid Pirahesh, Calisto Zuzarte
Venue: Proceedings of the 2004 ACM SIGMOD international conference on Management of data (2004)

Outerjoins are an important class of joins and are widely used in various kinds of applications. It is challenging to optimize queries that contain outerjoins because outerjoins do not always commute with inner joins. Previous work has studied this problem and provided techniques that allow certain reordering of the join sequences. However, the optimization of outerjoin queries is still not as powerful as that of inner joins.An inner join query can always be canonically represented as a sequence of Cartesian products of all relations, followed by a sequence of selection operations, each applying a conjunct in the join predicates. This canonical abstraction is very powerful because it enables the optimizer to use any join sequence for plan generation. Unfortunately, such a canonical abstraction for outerjoin queries has not been developed. As a result, existing techniques always exclude certain join sequences from planning, which can lead to a severe performance penalty.Given a query consisting of a sequence of inner and outer joins, we, for the first time, present a canonical abstraction based on three operations: outer Cartesian products, nullification, and best match. Like the inner join abstraction, our outerjoin abstraction permits all join sequences, and preserves the property of both commutativity and transitivity among predicates. This allows us to generate plans that are very desirable for performance reasons but that couldn't be done before. We present an algorithm that produces such a canonical abstraction, and a method that extends an inner-join optimizer to generate plans in an expanded search space. We also describe an efficient implementation of the best match operation using the OLAP functionalities in SQL:1999. Our experimental results show that our technique can significantly improve the performance of outerjoin queries.
Evaluating the Visual Manipulation with Cellular Automata-Like Algorithms
Authors: Mahmoud A. Saber, Nikolay Mirenkov
Venue: Proceedings of the International Conference on Computer Graphics, Imaging and Visualization (2004)

The Active Knowledge Studio group at the University of Aizu is studying, designing, and developing multimedia programming environments for various domains. One of the promising domains is the cellular automata where the global behavior of systems arises from the collective effect of many locally interacting, simple components. The cellular automata (CA) systems have a rich theoretical basis. They have also been used in a great variety of applications. A number of programming languages and environments have been developed to support the implementation of the CA models. However, these languages focus on computational and performance issues only, and do not pay enough attention to programming productivity, usability, understandability, and other aspects of software engineering. In this paper, we provide an outline of our approach to manipulating such systems in a visual user-oriented environment. Then, we explain features of the environment, present case studies, and describe the results of evaluating our visual environment.
Searching efficient plans for emergency rescue through simulation: the case of a metro fire
Authors: Nikos Zarboutis, Nicolas Marmaras
Venue: Cognition, Technology and Work (2004)

In this paper we present the way we modelled and simulated a metro system in the case of a tunnel fire, and discuss the ways this simulation may support the search for efficient rescue plans. The metro system was modelled as a complex adaptive system, comprising four interacting and co-evolving subsystems: (i) the fire and the released smoke, (ii) the group of passengers, (iii) the technological system, and (iv) the metro personnel. Based on this model, an agent-based simulation was developed. This simulation provides an appropriate dynamic representation of the designer&#x2019;s problem space, enabling him (i) to apprehend the critical dependencies and invariants of the system under consideration, (ii) to identify the features that should characterise the designed emergency rescue plans, and (iii) to assess their efficiency. To demonstrate the usefulness of the adopted approach for the design of an efficient emergency rescue plan, the results of two experiments exploring alternative sequences of the metro personnel&#x2019;s actions under different circumstances are presented.
Transient Fault Emulation of Hardened Circuits in FPGA Platforms
Authors: Mario Garcia-Valderas, Celia Lopez-Ongil, Marta Portela-Garcia, Luis Entrena-Arrontes
Venue: Proceedings of the International On-Line Testing Symposium, 10th IEEE (2004)

Very deep submicron and nanometer technologies areemphasizing soft errors as an important issue in thechallenges of modern electronic systems. Hardenedcircuits are currently required in many applications whereFault Tolerance (FT) was not a requirement in the verynear past. Together with the generation of tools andmethods for hardening circuits, new ways of validating theFT are needed. These solutions must be cost effective andprovide a help not only in measuring the robustness of thecircuit but also in locating the weak areas and inproposing hardening solutions. FPGA emulation of SEUeffect is gaining attention in order to speed up the FaultTolerance Evaluation.In this work a system is proposed for the evaluation offault tolerance with respect to SEU effects by emulation inplatform FPGAs. In this system, most of the modules of atypical fault injection environment are embedded in theFPGA. Therefore, time required for the FT validation hasbeen optimised with respect to existing approaches.
Living with Inconsistencies in a Multidatabase System
Authors: Janusz R. Getta
Venue: Proceedings of the Database and Expert Systems Applications, 15th International Workshop (2004)

Integration of autonomous sources of information is one of the most important problems in implementation of the global information systems. This work considers multidatabase systems as one of the typical architectures of global information services and addresses a problem of storing and processing inconsistent information in such systems. A new data model proposed in the paper separates sure from inconsistent information and introduces a system of elementary operations on the containers with sure and inconsistent information. A review of the implementation aspects in an environment of a typical relational database management system concludes the paper.
SPT is optimally competitive for uniprocessor flow
Authors: David P. Bunde
Venue: Information Processing Letters (2004)

We show that the Shortest Processing Time (SPT) algorithm is (Δ + 1)/2-competitive for nonpreemptive uniprocessor total flow time with release dates, where Δ is the ratio between the longest and shortest job lengths. This is best possible for a deterministic algorithm and improves on the (Δ + 1)-competitive ratio shown by Epstein and van Stee using different methods.