This study investigates the computer perceptions of students at home, at school and at internet cafe, and the computer applications they preferred. For this purpose, the frequency of computer usage, the applications t...
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The automatic programming system has been considered by means of which it becomes easier to carry out traditional programming stages. There is discussed both recursive forms: parallel, interrecursion and recursion of ...
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The automatic programming system has been considered by means of which it becomes easier to carry out traditional programming stages. There is discussed both recursive forms: parallel, interrecursion and recursion of high level that exist for functional programming languages and induction methods for the purpose of their verification. The way how to present imperative languages easy and double cycles by means of recursion forms is shown, the possibility of verification has been studied for each recursion form.
Pervasive computing in mobile ad hoc networks requires that applications query their network environment for services and react to a plethora of events fired by other devices in that network responding to such queries...
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ISBN:
(纸本)9781605583648
Pervasive computing in mobile ad hoc networks requires that applications query their network environment for services and react to a plethora of events fired by other devices in that network responding to such queries. Current context-aware and event-driven architectures require the programmer to react to these events via a carefully crafted network of observers and event handlers, while inherently introducing complex concurrency issues. This paper proposes the integration of two techniques to solve these problems: ambient references and reactive programming. Ambient references are object-oriented communication abstractions that represent nearby remote objects in the mobile network and that make it possible to generate the events mentioned above. The reactive programming paradigm provides an abstraction over events such that the application can be written in a conventional programming style with explicit control flow. Copyright 2008 ACM.
Extensions to the actor model have been proposed to ease the development of mobile ad hoc applications. However, programming in the actor model is still difficult as it does not provide abstractions to synchronously c...
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ISBN:
(纸本)9781605583648
Extensions to the actor model have been proposed to ease the development of mobile ad hoc applications. However, programming in the actor model is still difficult as it does not provide abstractions to synchronously coordinate multiple actors. Thus, when programmers want to coordinate two or more actors they have to do it by hand. Additionally, programmers need to write failure recovery code for failures caused by the concurrent access to the actors they are using. Coding this manually is error prone and might even be not feasible. We propose a language abstraction based on software transactional memory to coordinate actors. We show that the integration of software transactional memory with the actor model makes writing failure recovery code superuous. Moreover, we show that our system even handles those cases where manually writing the failure recovery code is not feasible. Copyright 2008 ACM.
The paper presents the study of the human body, as a mechanical system, seated inside an autovehicle and exposed under the vertical harmonic vibration action during the auto vehicle motion time. The human body may be ...
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.
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...
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.
In this paper, we propose an On-Demand Content Delivery Grid system that supplements the traditional content delivery network to deal with problems such as the huge influx of network traffic in a short period of time ...
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ISBN:
(纸本)9780980326727
In this paper, we propose an On-Demand Content Delivery Grid system that supplements the traditional content delivery network to deal with problems such as the huge influx of network traffic in a short period of time and the high cost in renting a fixed number of servers. We present its system architecture and describe its implementation in details. An experimental high-definition movie streaming site was setup using our content delivery grid system to demonstrate its capabilities with performance analysis.
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