A DSM protocol ensures that a thread can access data allocated on another machine using some consistency protocol. The consistency protocol can either replicate the data and unify replica changes periodically or the t...
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ISBN:
(纸本)9780889867741
A DSM protocol ensures that a thread can access data allocated on another machine using some consistency protocol. The consistency protocol can either replicate the data and unify replica changes periodically or the thread, upon remote access, can migrate to the machine that hosts the data and access the data there. There is a performance tradeoff between these extremes. Data replication suffers from a high memory overhead as every replicated object or page consumes memory on each machine. On the other hand, it is as bad to migrate threads upon each remote access since repeated accesses to the same distributed data set will cause repeated network communication whereas replication will incur this only once (at the cost of increased administration overhead to manage the replicas). We propose a hybrid protocol that uses selective replication with thread migration as its default. Even in the presence of extreme memory pressure and thread-migrations, our protocol reaches or exceeds the performance that can be achieved by means of manual replication and explicit changes of the application's code.
OPC is a matured and accepted standard in industries, but hardly used in industrial applications developed at universities, especially in Europe. Publications in this area, either using OPC-communication or developing...
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OPC is a matured and accepted standard in industries, but hardly used in industrial applications developed at universities, especially in Europe. Publications in this area, either using OPC-communication or developing applications have been hardly increased over the past several years. This paper reports the current state of the standard, but also describes current problems and how they can be managed and overcome. The authors also give an overview of the recently published new standard, which is called: OPC unified approach. After the fundamentals are described in this paper, the authors present their experiences with OPC to combine it with methods and procedures to develop a modern maintenance system. It also reports current developments at the Department of computer Architecture and System programming at the University of Kassel.
We have designed and implemented game-themed programming assignment modules targeted specifically for adoption in existing introductory programming classes. These assignments are self-contained, so that faculty member...
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ISBN:
(纸本)9781605580579
We have designed and implemented game-themed programming assignment modules targeted specifically for adoption in existing introductory programming classes. These assignments are self-contained, so that faculty members with no background in graphics/gaming can selectively pick and choose a subset to combine with their own assignments in existing classes. This paper begins with a survey of previous results, followed by a description of the game-themed assignment modules. The paper then focuses on our efforts in assessing the assignments: including details of the procedures and instruments for evaluating student achievement of learning outcomes and attitudes towards the assignments, as well as the extra effort required of faculty to adopt the assignments in existing clases. Copyright 2008 ACM.
Learning computer science is no longer simply a matter of learning computerprogramming. Indeed, modern day computing jobs demand design, communication and collaborative skills as well. In order to address this need a...
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ScatterFactory2 is a model-driven eclipse-based framework for the new generation of our WSN platform ScatterWeb The already deployed Modular Sensor Boards (MSBs) can be configured, programmed and tested at the same ti...
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If you want to program a parallel computer, a purely functional language like Haskell is a promising starting point. Since the language is pure, it is by-default safe for parallel evaluation, whereas imperative langua...
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Longitudinal elasticity modulus, E, is a material specific feature, which,. in general, is establish on the pieces by longitudinal stress. This procedure is possible to apply to the compact material but not to the sin...
As memory transactions have been proposed as a language-level replacement for locks, there is growing need for well-defined semantics. In contrast to database transactions, transaction memory (TM) semantics are compli...
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ISBN:
(纸本)9781595939739
As memory transactions have been proposed as a language-level replacement for locks, there is growing need for well-defined semantics. In contrast to database transactions, transaction memory (TM) semantics are complicated by the fact that programs may access the same memory locations both inside and outside transactions. Strongly atomic semantics, where non-transactional accesses are treated as implicit single-operation transactions, remain difficult to provide without specialized hardware support or significant performance overhead. As an alternative, many in the community have informally proposed that a single global lock semantics [18, 10], where transaction semantics are mapped to those of regions protected by a single global lock, provide an intuitive and efficiently implementable model for programmers. In this paper, we explore the implementation and performance implications of single global lock semantics in a weakly atomic STM from the perspective of Java, and we discuss why even recent STM implementations fall short of these semantics. We describe a new weakly atomic Java STM implementation that provides single global lock semantics while permitting concurrent execution, but we show that this comes at a significant performance cost. We also propose and implement various alternative semantics that loosen single lock requirements while still providing strong guarantees. We compare our new implementations to previous ones, including a strongly atomic STM. [24] Copyright 2008 ACM.
The authors present their latest research results and developments of a code generator for Matlab / Simulink block diagrams and to download the generated code onto safety related systems such as a safety PLC (Programm...
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