Dependable distributed embedded systems (DDES) are being deployed widely in automobile industry over the world. These systems always post rigorous requirement for timing accuracy and reliability. Both hardware and sof...
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ISBN:
(纸本)0769529097
Dependable distributed embedded systems (DDES) are being deployed widely in automobile industry over the world. These systems always post rigorous requirement for timing accuracy and reliability. Both hardware and software architecture have important effect on the system dependability. Adding or substitute for more reliable hardware could increase the system reliability moreover achieves faster system response. Apparently this would increase the manufacturing cost, while software could be a more cost-effective ways for providing support for dependable distributed embedded system development. The dependable distributed embedded system assessment platform (DDESAP) which based on vehicle control system provides testing and assessment support for various automobile dependable software. DDESAP evaluates the vehicle control hardware and operational environments. Software architectures such as time-triggered, event-triggered, hybrid-triggered and other fault tolerant mechanisms for dependable distributed embedded systems were tested on DDESAP. A vehicle dynamic model, a motorway traffic model, and a driver model were developed for DDESAP. simulation show these models comply with manufacturer and empirical data. DDESAP enables the evaluation of novel software architectures for safety-critical automobile control systems, like the fault tolerant adaptive cruise control systems (ACCS) presented.
This paper present a comparison of scheduling algorithms applied to the context of load balancing the query traffic on distributed inverted files. We implemented a number of algorithms taken from the literature. We pr...
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ISBN:
(纸本)9781595938299
This paper present a comparison of scheduling algorithms applied to the context of load balancing the query traffic on distributed inverted files. We implemented a number of algorithms taken from the literature. We propose a novel method to formulate the cost of query processing so that these algorithms can be used to schedule queries onto processors. We avoid measuring load balance at the search engine side because this can lead to imprecise evaluation. Our method is based on the simulation of a bulk-synchronous parallel computer at the broker machine side. This simulation determines an optimal way of processing the queries and provides a stable baseline upon which both the broker and search engine can tune their operation in accordance with the observed query traffic. We conclude that the simplest load balancing heuristics are good enough to achieve efficient performance. Our method can be used in practice by broker machines to schedule queries efficiently onto the cluster processors of search engines. Copyright 2007 ACM.
An inductively-degenerated common-source (CS) open-drain cascode LNA was designed for W-CDMA application. The operating frequency for the design was at 2.14 GHz which is at the center of the reception range Of the W-C...
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ISBN:
(纸本)9781424413072
An inductively-degenerated common-source (CS) open-drain cascode LNA was designed for W-CDMA application. The operating frequency for the design was at 2.14 GHz which is at the center of the reception range Of the W-CDMA standard. The supply voltage is 1.8V at 0.18 mu m CMOS process. The LNA was designed using power-constrained noise optimization method in obtaining the width of the transistor of 290 gm. Post-layout simulations with distributed resistors and capacitors were performed. On-chip inductors with quality factor of 8 were utilized to resonate with the metal-insulator-metal capacitor (mimcap). The mimcap was also used to isolate V-DD and ground. The input was 50 Omega matched using the transistor as well as an inductor at the gate and three parallel 1.65 nH inductors acting as a 0.55 nH degeneration inductor at the source. Detailed design steps are described in this paper wih plots of the post-layout simulation and measurement results provided. These plots are analyzed extensively in this paper and justification for the errors are given. The 12.8 dB of S-21 obtained from the post-layout and a much less 7.8 dB from the measurement shows that there is an offset by 5 dB. Derivations are given to show that the unmatched output is the cause of the gain offset. S-11 is measured at -24 dB which is very close to the simulated value of -25.4 dB. The current measured and simulated at a bias voltage of 0.65 V is 4.1 mA.
The proceedings contain 30 papers. The topics discussed include: improving lookahead in parallel multiprocessor simulation using dynamic execution path prediction;the distributed open network emulator: using relativis...
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ISBN:
(纸本)0769525873
The proceedings contain 30 papers. The topics discussed include: improving lookahead in parallel multiprocessor simulation using dynamic execution path prediction;the distributed open network emulator: using relativistic time for distributed scalable simulation;performance analysis of shared data access algorithms for distributedsimulation of multi-agent systems;predicting performance of resolution changes in parallelsimulations;what comes after the semantic web? PADS implications for the dynamic web;discrete-event execution alternatives on general purpose graphical processing units;developing an hierarchical simulator for Beta-binders;greedy algorithms for client assignment in large-scale distributed virtual environments;and interest operators: facilitating attribute interest criteria for formula-based interest management in distributed virtual environments.
A master/worker paradigm for executing large-scale parallel discrete event simulation programs over network-enabled computational resources is proposed and evaluated. In contrast to conventional approaches to parallel...
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simulation performance is dominated by lookahead in null message-based conservative time management of parallel discrete event simulation (PDES). This paper proposes a scheme for software execution path prediction to ...
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parallelsimulation techniques are designed to increase simulation model performance by exploiting model concurrency. Unfortunately, designing efficient parallelsimulations is not always an easy task. Most existing t...
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In dynamic bulk synchronous computations, processors may change their workloads from phase to phase. Such workload change will possibly increase the duration of a phase and the overall parallel execution time. Therefo...
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ISBN:
(纸本)0769521320
In dynamic bulk synchronous computations, processors may change their workloads from phase to phase. Such workload change will possibly increase the duration of a phase and the overall parallel execution time. Therefore, it is necessary to redistribute workload at runtime to reduce the parallel time. However, such workload redistribution at runtime can be expensive and the overhead of frequent runtime workload redistribution may exceed the benefit of workload redistribution and balancing. The problem of finding the optimal period of runtime workload redistribution for dynamic bulk synchronous computations is motivated by the combined consideration of parallel execution time and system overhead for workload redistribution and balancing. We develop an analytical method to solve the problem in heterogeneous computing systems. We also demonstrate numerical data of the analytical method and simulation results that verify the analytical data.
simulation is a low cost alternative to experimentation on real-world physical systems. Grid technology enables coordinated use of and secure access to distributed computing resources and data sources. The service-ori...
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This paper presents the parallel numerical simulation of 3-D compressible strongly rotating viscous flows by solving Navier-Stokes equations using meshless Least Square Kinetic Upwind Method (LSKUM) solver. The paper ...
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This paper presents the parallel numerical simulation of 3-D compressible strongly rotating viscous flows by solving Navier-Stokes equations using meshless Least Square Kinetic Upwind Method (LSKUM) solver. The paper describes the LSKUM solver and also addresses the various issues that arise while parallelisation is carried out for LSKUM-NS code for viscous compressible flows using a typical distributed memory architecture. The computational fluid dynamic (CFD) simulation showed a large sized subsonic pocket with a vortex ahead of the stationary body. The parallel meshless CFD code coupled with diffusion and optimization code is capable of solving many viscous rotating flows.
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