Synchronization plays an important role in multimedia systems at various levels of abstraction. In this paper, we propose a set of powerful abstractions for controlling and synchronizing continuous media streams in di...
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Synchronization plays an important role in multimedia systems at various levels of abstraction. In this paper, we propose a set of powerful abstractions for controlling and synchronizing continuous media streams in distributed environments, The proposed abstractions are based on a very general computation model, that allows media streams to be processed (i.e. produced, consumed or transformed) by arbitrarily structured networks of linked components, Further, compound components can be composed of existing ones to provide higher levels of abstractions, The clock abstraction is provided to control individual media streams, i.e., streams can be started, paused or scaled by issuing the appropriate clock operations. Clock hierarchies are used to hierarchically group related streams, where each clock in the hierarchy identifies and controls a certain group, or subgroup of streams, Control and synchronization requirements can be expressed in a uniform manner by associating group members with control or sync attributes, An important property of the concept of clock hierarchy is that it can be combined in a natural way with component nesting.
Driven by the question how to identify potential communication partners and the need for well-suited communication schemes in agent-based systems, we discuss two communication concepts: sessions and global event manag...
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ISBN:
(纸本)3540628037
Driven by the question how to identify potential communication partners and the need for well-suited communication schemes in agent-based systems, we discuss two communication concepts: sessions and global event management. Sessions establish either actively or passively a context for inter-agent interactions. Communication partners are addressed by globally unique agent identifiers or via badges. Communication in sessions is based on RPC or message mechanisms. Global event management addresses the need for anonymous communication. Event managers are employed as a synchronization means within agent groups. Based on this approach, we introduce synchronization objects, - active components that offer various synchronization services. The presented model is finally mapped onto OMG event services.
Workstation clusters are being recognized as the main promising computing resource of the near future. A large size workstation cluster, consisting of locally connected workstations, has the power comparable to a supe...
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ISBN:
(纸本)3540593934
Workstation clusters are being recognized as the main promising computing resource of the near future. A large size workstation cluster, consisting of locally connected workstations, has the power comparable to a supercomputer, at a fraction of the cost. Further, a wide area coupling of workstation clusters is not only suitable for exchange of mail and news or establishment of distributed information systems, but can also be exploited as a large metacomputer. The wide area distribution aspects will be covered in a separate paper by the E=MC(2) project [8]. This paper shows the potential power by characterizing the system and the needs of current applications, and outlines the general idea to efficiently utilize networks of workstation. The second part of the paper introduces the approach of the HiCon project to solve the operating system and programming environment problems that currently restrict proper exploitation of workstation clusters, and demonstrates the feasibility by real measurement results. It concludes with general results for the research community in this area.
The introduction of parallel computers is substantially slowed down by the difficulties of writing parallel programs. Fully automatic general parallelization is not feasible in the near future. The GRIDS programming s...
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The introduction of parallel computers is substantially slowed down by the difficulties of writing parallel programs. Fully automatic general parallelization is not feasible in the near future. The GRIDS programming system addresses this problem by offering an easy-to-use programming model for grid-based scientific computations. The code is parallelized automatically and executed efficiently by the GRIDS runtime system.
One of the main tasks of workflow management systems is the coordination of activities in business processes. This paper introduces a solution framework to support adaptive workflows with complex and unstructured task...
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The model system DRAIS-RADM describing meteorological and chemical processes in a mesoscale area is especially used to simulate the distribution of concentrations of chemical reactants in the atmosphere. The high expe...
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An Algorithm for finding the optimal path given the initial and final positions of a cylinder-shaped mobile robot with the constraint on minimizing the search efforts is presented in this paper. This algorithm is base...
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The World Wide Web is the largest collection of documents that ever existed. Users of this information space do need tools for simple and powerful retrieval of the information they are interested in. But the existing ...
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