The complexity of today's embedded real-time systems is continuously growing with high demands on dependability, resource-efficiency, and reusability Two solution approaches address these needs: First, in the comp...
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ISBN:
(纸本)9781424416936
The complexity of today's embedded real-time systems is continuously growing with high demands on dependability, resource-efficiency, and reusability Two solution approaches address these needs: First, in the component based softwareengineering (CBSE) paradigm, software is decomposed into self-contained components with explicit interactions and context dependencies. Connectors represent the abstraction of interactions between these components. Second, components can be shifted from software to reconfigurable hardware, typically field programmable gate arrays (FPGAs), in order to meet real-time constraints. This paper proposes a component-based concept to support efficient hardware/software co-design: A hardware component together with the hardware/soflware connector can seamlessly replace a software component with the same functionality, while the particularities of the alternative interaction are encapsulated in the component connector. Our approach provides for tools that can generate all necessary interaction mechanisms between hardware andsoftware components. A proof-of-concept application demonstrates the advantages of our concept: Rapid change and comparison of different partitioning decisions due to automated and faultless generation of the hardware/software connectors.
Memory errors, Such as memory leaks and bounds violations are often the source of the kind of bugs that are especially challenging for scientists, computer scientists and engineers to resolve. This paper describes a n...
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ISBN:
(纸本)9783540685616
Memory errors, Such as memory leaks and bounds violations are often the source of the kind of bugs that are especially challenging for scientists, computer scientists and engineers to resolve. This paper describes a new software development tool called MernoryScape that provides developers with a highly graphical and interactive memory debugging tool. MernoryScape can be used to troubleshoot problems on applications ranging from serial applications for the desktop or server Lip to massively multprocess applications running on supercomputers. This paper provides an introduction to some of the challenges of memory debugging in parallel architectures, reviews the memory errors detected and provides an overview of the Heap Interposition Agent (HIA) andparallel debugging technology that makes this possible.
Loose coupling and preserving safe changes are two key criteria for composing self-managing services. Composition of adaptive control components with business services without interfering with the original service ope...
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ISBN:
(纸本)9781605580296
Loose coupling and preserving safe changes are two key criteria for composing self-managing services. Composition of adaptive control components with business services without interfering with the original service operations is complicated by the dynamic and highly distributed nature of service-oriented systems. Essentially, encapsulating control logic into abstract logical models enables a clear separation of concerns, with states and transitions indicating the logical control flow. The challenge is to seamlessly integrate these models with services and their host infrastructure as a unified self-managing environment. In this paper, we present an architectural solution towards process-based composition and coordination of self-managing services. This architecture framework leverages business process models to produce declarative and executable control models. We discuss the problem context and outline the research challenges of such an approach. Copyright 2008 ACM.
PSL is a kind of temporal logic which uses SEREs as additional formula constructs. We present a variant of PSL, namely APSL, which replaces SEREs with finite automata. APSL and PSL are of the exactly same expressivene...
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ISBN:
(纸本)9780769532493
PSL is a kind of temporal logic which uses SEREs as additional formula constructs. We present a variant of PSL, namely APSL, which replaces SEREs with finite automata. APSL and PSL are of the exactly same expressiveness. In this paper we extend the LTL symbolic model checking algorithm to that of APSL, and present a tableau based APSL verification approach. Moreover we show how to implement this algorithm via the BDD based symbolic approach.
The proceedings contain 14 papers. The topics discussed include: an Internet-based laboratory course in chemical reaction engineering and unit operations;Internet based laboratory for experimentation with multilevel m...
ISBN:
(纸本)9783940793171
The proceedings contain 14 papers. The topics discussed include: an Internet-based laboratory course in chemical reaction engineering and unit operations;Internet based laboratory for experimentation with multilevel medium-power converters;content management and architectural issues of a remote learning laboratory;distributedsoftware architecture and applications for remote laboratories;tele-lab IT-security: an architecture for an online virtual IT security lab;a flexible instructional electronics laboratory with local and remote lab workbenches in a grid;simulation of an intelligent network - basic call state model remote laboratory;SOA meets robots - a service-based software infrastructure for remote laboratories;a virtual laboratory for digital design;virtual and remote laboratories feasibility study and development guidelines;and a training need analysis of trainers in the field of technical vocational education training.
Gossip-based Peer-to-Peer(P2P) streaming has been proved to be an effective and resilient method to stream qualified media contents in dynamic and heterogeneous network environments. Because of the intrinsic randomnes...
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ISBN:
(纸本)9781424416936
Gossip-based Peer-to-Peer(P2P) streaming has been proved to be an effective and resilient method to stream qualified media contents in dynamic and heterogeneous network environments. Because of the intrinsic randomness of gossiping, some data segments cannot be disseminated to every node in time, which seriously affects the media playback continuity. In this paper we describe the design of ContinuStreaming, a gossip-based P2P streaming system which can maintain high resilience and low overhead while bring a novel and critical property - full coverage of the data dissemination. With the help of DHT, data segments which are likely to be missed by the gossip-based data scheduling can be quickly fetched by the on-demand data retrieval so as to guarantee continuous playback. We discuss the results of both theoretical analysis and comprehensive simulations on various real-trace overlay topologies to demonstrate the effectiveness of our system. Simulation results show that ContinuStreaming outperforms the existing representative gossip-based P2P streaming systems by increasing the playback continuity very close to 1.0 with only 4% or less extra overhead.
P2P Grids are Grids organized into P2P networks where participant exchange computing time so as to complete computational tasks. Evaluating the performance of scheduling algorithms enables one to deploy those that are...
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ISBN:
(纸本)9781605580524
P2P Grids are Grids organized into P2P networks where participant exchange computing time so as to complete computational tasks. Evaluating the performance of scheduling algorithms enables one to deploy those that are efficient. Performance is often evaluated experimentally or through simulation because these algorithms (typically heuristics) are too complex to model analytically. Testing the implementation of P2P Grid middleware before it is deployed is also important: Reproducing configurations or conditions that lead to unexpected outcomes is thus valuable. A P2P Grid environment exhibits multiple sources of failure and is typically dynamic and uncontrollable. Reproducing even basic behavior of Grid nodes in a controllable and repeatable manner is thus exceedingly difficult. Such lack of control over the environment is a major challenge in the softwareengineering of P2P Grid middleware [7]. Simulators have been proposed to evaluate the performance of scheduling algorithms, but are often limited in scope, reusability and accuracy, i.e. they rely on simplified models. We introduce a softwareengineering pattern - that we call code once, deploy twice - to both reduce the distance between simulated and implemented algorithms and reproduce, at will, Grid configurations and environments: A simulator implementation of a Grid architecture is built by virtualizing its middleware implementation. An immediate benefit is that most of the code can be reused between both implementations;only communications between Grid nodes, multithreading within Grid nodes and actual task execution are coded differently. As a derived benefit, most of the code of the middleware can be tested within the controlled environment of the simulator, before it is deployed as-is. Another benefit is high simulation accuracy. We describe the implementation of a P2P Grid following the code once, deploy twice pattern, that we believe is also relevant to other Grid types (certainly Volunteer Grids [5, 4]
High Performance Reconfigurable Computers (HPRCs) consist of one or more standard microprocessors tightly coupled with one or more reconfigurable FPGAs. HPRCs have been shown to provide good speedups and good cost/per...
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A system is designed for dielectric parameterspsila measurement of microwave ceramic materials in which rotary open cavity is applied and the theoretic analysis is presented. With the stepping motor controlled by Sing...
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A system is designed for dielectric parameterspsila measurement of microwave ceramic materials in which rotary open cavity is applied and the theoretic analysis is presented. With the stepping motor controlled by Single-Chip Microchip, the measurement can be realized automatically. The analysis software based on VEE is programmed, so that the measurement data from Vector Network Analyzer can be calculated and analyzed directly. The result and errors by comparing the method of open and short parallel-plate can evaluate the accuracy and precision of the measurement system.
Performance is a key feature of large-scale computing systems. However, the achieved performance when a certain program is executed is significantly lower than the maximal theoretical performance of the large-scale co...
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Performance is a key feature of large-scale computing systems. However, the achieved performance when a certain program is executed is significantly lower than the maximal theoretical performance of the large-scale computing system. The model-based performance evaluation may be used to support the performance-oriented program development for large-scale computing systems. In this paper we present a hybrid approach for performance modeling and prediction of parallel anddistributed computing systems, which combines mathematical modeling and discrete-event simulation. We use mathematical modeling to develop parameterized performance models for components of the system. Thereafter, we use discrete-event simulation to describe the structure of system and the interaction among its components. As a result, we obtain a high-level performance model, which combines the evaluation speed of mathematical models with the structure awareness and fidelity of the simulation model. We evaluate empirically our approach with a real-world material science program that comprises more than 15,000 lines of code.
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