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作者： Hermanns, Marc-André Geimer, Markus Mohr, Bernd Wolf, Felix Laboratory for Parallel Programming German Research School for Simulation Sciences GmbH 52425 Jülich Germany Forschungszentrum Jülich Jülich Supercomputing Centre Germany Department of Computer Science RWTH Aachen University Germany

Wait states in parallel applications can be identified by scanning event traces for characteristic patterns. In our earlier work we defined such inefficiency patterns for MPI-2 one-sided communication, although still based on a serial trace-analysis scheme with limited scalability. In this article we show how wait states in one-sided communications can be detected in a more scalable fashion by taking advantage of a new scalable trace-analysis approach based on a parallel replay, which was originally developed for MPI-1 point-to-point and collective communication. Moreover, we demonstrate the scalability of our method and its usefulness for the optimization cycle with applications running on up to 32,768 cores. © The Author(s) 2012.

关键词： Scalability

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Formal specification of virtual process topologies

Formal specification of virtual process topologies

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IEEE International Conference on Cluster Computing

作者： K. Kazemi C. McDonald Programming Languages and Systems Group Department of Computer Science University of Western Australia Nedlands WA Australia

A lack of adequate and flexible topology support in the popular message passing systems such as Parallel Virtual Machine was a major factor in the development of our Virtual Process Topology Environment. This parallel programming environment provides high level abstractions for interprocess communication, relieving the application developer of the cumbersome task of mapping logical neighbours to their task identifiers within message passing systems. The novel approach of separating topological specification from the APIs provided extreme flexibility to the developers of the applications using regular topologies. We believed that the task of supporting process topologies could be made even easier and, in this paper present our new method which uses recurrence relations to define topologies. Within the new environment, the recurrence relationships can be passed to the topology server which then is used in the generation of the topological specification.

关键词： Formal specifications Message passing Libraries Network topology Workstations Supercomputers computer languages computer science Read only memory Network servers

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A constraint-based approach for specification and verification of real-time systems

A constraint-based approach for specification and verificati...

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Real-Time Systems Symposium (RTSS)

作者： G. Gupta E. Pontelli Laboratory for Logic Databases and Advanced Programming Department Computer Science New Mexico State University USA

We develop a general constraint logic programming (CLP) based framework for specification and verification of real time systems. Our framework is based on the notion of timed automata that have traditionally been used for specifying real time systems. In our framework, a user models the ordering of real time events as the grammar of a language accepted by a timed automata, the real time constraints on these events are then captured as denotations of the grammar productions specified by the user. The grammar can be specified as a Definite Clause Grammar (DCG), while the denotations can be specified in constraint logic. The resulting specification can hence be regarded as a constraint logic program (CLP), and is executable. Many interesting properties of the real time system can be verified by posing appropriate queries to this CLP program. A major advantage of our approach is that it is constructive in nature, i.e., it can be used for computing the conditions under which a property will hold for a given real time system. Our framework also suggests new types of formalisms that we call constraint automata and timed push down automata.

关键词： Real time systems Automata Logic programming Production systems Databases computer science Vehicles Clocks Context modeling

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Core technologies for system renovation 23rd

Core technologies for system renovation

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23rd Seminar on Current Trends in Theory and Practice of Informatics, SOFSEM 1996

作者： Van Den Brand, Mark Klint, Paul Verhoef, Chris Programming Research Group University of Amsterdam Kruislaan 403 AmsterdamNL-1098 SJ Netherlands Department of Software Technology Centre for Mathematics and Computer Science P.O. Box 4079 AmsterdamNL-1009 AB Netherlands

ISBN: (纸本)3540619941

Renovation of business-critical software is becoming increasingly important. We identify fundamental notions and techniques to aid in system renovation and sketch some basic techniques: generic language technology to build analysis tools, a knowledge retrieval system to aid in program understanding, and a coordination architecture that is useful to restructure monolithic systems thus enabling their renovation. We argue that these techniques axe not only essential for the renovation of old software but that they can also play an important role during the development and maintenance of new software systems. © 1996, Springer-Verlag. All rights reserved.

关键词： Artificial intelligence

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Cyclic Quasi-Orthogonal Matrices in Image and Signal Encoding

Cyclic Quasi-Orthogonal Matrices in Image and Signal Encodin...

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International Conference on Information Science and Communications Technologies (ICISCT)

作者： Sergeev Alexandr Department of computer technology and programming Saint Petersburg State University of Aerospace Instrumentation Saint Petersburg Russia

orthogonal and quasi-orthogonal matrices with a limited number of element values and structured in some way are of considerable interest for many technical applications related to image processing and signal coding. The paper classifies and considers cyclic matrices and matrices with cyclic blocks. Descriptions of noise-resistant encoding methods of images and their protective masking using such matrices are given. Based on the analysis of the autocorrelation functions of new code sequences obtained from strings of modified cyclic quasi-orthogonal matrices and the simulation performed, numerical values of the quality parameters of the new code sequences are given. It is shown that their application makes it possible to reduce the maximum level of the side lobe of the aperiodic autocorrelation function, which allows us to conclude that their application is promising and that signal coding algorithms can be revised.

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Modelica - a general object-oriented language for continuous and discrete-event system modeling and simulation

Modelica - a general object-oriented language for continuous...

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Annual Symposium on Simulation

作者： P. Fritzson P. Bunus PELAB-Programming Environment Laboratory Department of Computer and Information Science Linköping University Linkoping Sweden

Modelica is a general equation-based object-oriented language for continuous and discrete-event modeling of physical systems for the purpose of efficient simulation. The language unifies and generalizes previous object-oriented modeling languages. It is bringing about a revolution in this area, based on its ease of use, visual design of models with combination of Lego-like predefined model building blocks, its ability to define model libraries with re-usable components and its support for modeling and simulation of complex applications involving parts from several application domains. In this paper we present the Modelica language with emphasis on its language features and one of the associated simulation environments. Simulation models can be developed in an integrated problem-solving environment by using a graphical editor for connection diagrams. Connections are established just by drawing lines between objects picked from a class library. The principles of object oriented physical systems modeling and the multi-domain capabilities of the language are presented in the paper by several examples.

关键词： Object oriented modeling Discrete event systems Electrical capacitance tomography Equations Biological system modeling Mathematical model computer simulation Thermodynamics Application software Computational modeling

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Specification, implementation, and verification of Domain Specific Languages: A logic programming-based approach

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Lecture Notes in computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2002年 2407卷 211-239页

作者： Gupta, Gopal Pontelli, Enrico Applied Logic Programming Languages and Systems Lab. Department of Computer Science University of Texas at Dallas Richardson TX 95083 United States Laboratory for Logic Databases and Advanced Programming Department of Computer Science New Mexico State University Las Cruces NM 88003 United States

ISBN: (纸本)3540439595

Domain Specific Languages (DSLs) are high level languages designed for solving problems in a particular domain, and have been suggested as means for developing reliable software systems. We present a (constraint) logic programming-based framework for specification, efficient implementation, and automatic verification of domain specific languages (DSLs). Our framework is based on using Horn logic (or pure Prolog), and eventually constraints, to specify denotational semantics of domain specific languages. Both the syntax as well as the semantic specification of the DSL in question are directly executable in our framework: the specification itself serves as an interpreter for the DSL. More efficient implementations of this DSL-a compiler-can be automatically derived via partial evaluation. Additionally, the executable specification can be used for automatic or semi-automatic verification of programs written in the DSL as well as for automatically obtaining traditional debuggers and profilers. The ability to verify DSL programs is a distinct advantage of our approach. In this paper we give a general outline of our approach, and illustrate it with practical examples. © 2002 Springer-Verlag Berlin Heidelberg.

关键词： Specifications

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Kinesthetics eXtreme: an external infrastructure for monitoring distributed legacy systems

Kinesthetics eXtreme: an external infrastructure for monitor...

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International Workshop on Active Middleware Services

作者： G. Kaiser J. Parekh P. Gross G. Valetto Department of Computer Science Programming Systems Laboratory Columbia University USA Telecom Italia Laboratory Italy

Autonomic computing - self-configuring, self-healing, self-optimizing applications, systems and networks - is widely believed to be a promising solution to ever-increasing system complexity and the spiraling costs of human system management as systems scale to global proportions. Most results to date, however, suggest ways to architect new software constructed from the ground up as autonomic systems, whereas in the real world organizations continue to use stovepipe legacy systems and/or build ''systems of systems'' that draw from a gamut of new and legacy components involving disparate technologies from numerous vendors. Our goal is to retrofit autonomic computing onto such systems, externally, without any need to understand or modify the code, and in many cases even when it is impossible to recompile. We present a meta-architecture implemented as active middleware infrastructure to explicitly add autonomic services via an attached feedback loop that provides continual monitoring and, as needed, reconfiguration and/or repair. Our lightweight design and separation of concerns enables easy adoption of individual components, as well as the full infrastructure, for use with a large variety of legacy, new systems, and systems of systems. We summarize several experiments spanning multiple domains.

关键词： computerized monitoring computer networks Application software Middleware Costs Humans Feedback loop Software maintenance Hardware Conferences

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Advanced IOT Traffic Light Control System 5

Advanced IOT Traffic Light Control System

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5th International Conference on Advances in Computational Tools for Engineering Applications, ACTEA 2023

作者： Hamad, Martin Abou El Hajj, Antonio Daou, Roy Abi Zeid Hayek, Ali Haidar, Gaby Abou Lebanese German University Faculty of Public Health Biomedical Technologies Department Lebanon MART Learning Education and Research Center Lebanon University of Kassel Department of Computer Architecture and System Programming Kassel Germany American University of Science and Technology Engineering Faculty Zahle Lebanon

ISBN: (纸本)9798350309959

For several years, traffic congestion has been a major problem in big cities where the number of cars and different means of transportation has been increasing significantly. The problem of congestion is becoming more and more critical, and if not treated smartly this issue will negatively affect drivers by wasting time and fuel gas while waiting for hours in lanes. This paper presents a new and smart way to mitigate this issue in an affordable cost, minimum processing power, and low power consumption. This concept takes into consideration the majority of the cases that may cause congestion and presents a smart and accurate outputs to ease traffic flow leading to the prediction of the peak hours of traffic congestion for smarter control. A model is designed to study the case of a four lanes crossroad with two traffic lights and two LCD monitors. The strategy in reading data is divided into two parts: real data from sensors and pre collected data from google maps to create a kind of a predicted pattern over a certain time interval. The responsiveness of the system is analyzed thoroughly, and the accuracy of all possible cases is carefully considered and evaluated. Each part of the system was tested alone, and the overall system is still in an ongoing testing phase. The results have shown minimum faulty errors and accepted outputs that can lead to safe traffic control decisions. Finally, integrating more IoT devices and sensors between V2V, V2P, V2I with the help of artificial intelligence will definitely optimize this system with higher accuracy. © 2023 IEEE.

关键词： Traffic congestion

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Predicting Parameter Sweep Jobs: From Simulation to Grid Implementation

Predicting Parameter Sweep Jobs: From Simulation to Grid Imp...

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International Conference on Complex, Intelligent and Software Intensive Systems, CISIS

作者： Peter Hellinckx Sam Verboven Frans Arickx Jan Broeckhove Research Group Computational Modeling and Programming Department of Mathematics and Computer Sciences University of Antwerp Antwerp Belgium

ISBN: (纸本)9781424435692

Efficiently using the computational power made available through desktop grids based distributed systems is a complicated and many-sided problem, caused by the intermittent resource availability. In this paper a novel solution is presented for predicting the runtimes of parameter sweep jobs. These jobs are characterized by their lack of inter-dependence and suitability for runtime prediction by modeling. This makes them ideal candidates for deployment on volatile grid configurations using prediction based techniques. The parameter sweep prediction framework used to make the predictions is referred to as GIPSy (grid information prediction system). Previous research involving GIPSy has focused on results obtained during simulation were it is necessary to make some basic assumptions. By combining GIPSy with PGS (prediction based grid scheduling), an actual grid implementation, real results can be obtained. A detailed comparison between the expected results, based on simulation analysis, and the final results is given. Discrepancies are highlighted and possible causes are identified, solutions are proposed and implemented. By comparing the results for different model building configurations an optimal configuration is found that produces reliable result independent of the chosen job type. Results are presented for a quantum physics problem and two simulated workloads represented by sleep jobs.

关键词： Predictive models Availability Runtime Scheduling Computational modeling Grid computing Distributed computing Workstations Testing Computational intelligence

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