Currently, many multimedia or continuous media server system is under development on top of either workstations or high-end PCs clustered with high speed networking facilities. In this paper we introduce Crown, a cont...
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ISBN:
(纸本)0818672250
Currently, many multimedia or continuous media server system is under development on top of either workstations or high-end PCs clustered with high speed networking facilities. In this paper we introduce Crown, a continuous media server on clustered high performance PCs with Myrinet, fast network switching equipment, and then address CrownFS, a file system on top of Crown, to offer continuous media streams to many subscribers at the same time. For easy and rapid tuning of the performance of CrownFS, we prototyped it. Prototyping requires less efforts and costs than direct implementation. Also, more reliable system optimization is obtainable rather than simulation. By using the prototype, we measured the scalability of CrownFS according to disk access strategies.
This paper outlines an awareness application called Ticketape. Tickertape is a tool that displays event notifications in the form of scrolling messages across a single-line window. The Tickertape message window provid...
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This paper outlines an awareness application called Ticketape. Tickertape is a tool that displays event notifications in the form of scrolling messages across a single-line window. The Tickertape message window provides an interface to a world of highly tailorable transient information. We provide an overview of Tickertape features and then discuss its specific use within a semi-commercial research organisation. We note that although Tickertape's evolution was incidental rather than purposeful, it is being extensively used within our organisation. Usage data and interviews suggest that there is a select core group of users who use Tickertape for both work and leisure. Other more casual users use the tool sporadically for leisure purposes only. We highlight our current goal which is to optimise Tickertape usage within the work environment. Our long-term vision involves the incorporation of Tickertape into Orbit-Gold, our collaborative working environment and to make the tool accessible to external organisations.
Lee's algorithm (1961) for routing always finds a minimum length path, if one exists. We discuss an enhancement to an earlier maze-routing algorithm to reduce the number of zig-zag line segments in the routing pat...
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Lee's algorithm (1961) for routing always finds a minimum length path, if one exists. We discuss an enhancement to an earlier maze-routing algorithm to reduce the number of zig-zag line segments in the routing path. This method would find a path between two points, if one exists, on a rectangular grid of cells. A line search method using efficient data structures has been applied that would reduce the number of line segments in the path. Blocking cells are introduced as obstacles in finding the path. All line segments are considered as horizontal and vertical only. An implementation of the method and its experimental results are reported.
High Performance Fortran (HPF) is an effective language for implementing regular data parallel applications on distributed memory architectures, but it is not well suited to irregular, block-structured applications su...
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This paper defines a computational protocol for evaluating the performance of raster to vector conversion systems. The graphical entities handled by this protocol are continuous and dashed lines, arcs, and circles, an...
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The article reports on initial investigation into a software architecture for component systems. Described is a geometrically based, cellular framework for the organization of component computation and communication. ...
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The article reports on initial investigation into a software architecture for component systems. Described is a geometrically based, cellular framework for the organization of component computation and communication. These structures are called Cellular Component Manifolds. The starting point for this work is the observation that the concept of address space is a pervasive abstraction across all computing and communicating systems. Accordingly, a generalized model of an idealized address space is proposed. A particular geometry with a suitable algebraic structure is chosen to provide addressing within this model. This results in an n-dimensional, hierarchical, cellular aggregate address space that is also a vector space with "nice" properties. The address spare, when populated with suitable components, becomes a Cellular Component Manifold. A component system architecture is given. This software architecture consists of three major layers: component framework framework, component frameworks and components. In addition to providing a basis for component system organization, this structure natively supports a range of scientific and engineering applications. As an example, the architecture is applied to the problem of handoff management in wireless overlay networks.
This paper presents a new fine-grained temporal Petri net model for distributed multimedia synchronization that can handle fuzzy temporal requirements and facilitate to verify the possibility of satisfying QoS require...
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This paper presents a new fine-grained temporal Petri net model for distributed multimedia synchronization that can handle fuzzy temporal requirements and facilitate to verify the possibility of satisfying QoS requirements. We present a procedure for constructing the fine-grained model, starting from a set of relative temporal relations among multimedia objects. And we give an approach to infer unknown durations. Finally, we discuss how to model intra-stream and inter-stream synchronizations so as to guarantee the QoS.
We present a software architecture which facilitates nomadic computing in an open distributed computing environment. We introduce a model for the description of mobile objects (users, computers and application objects...
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We present a software architecture which facilitates nomadic computing in an open distributed computing environment. We introduce a model for the description of mobile objects (users, computers and application objects) and their types. The descriptions create an information base for protocols managing mobility of the mobile objects. We present an architecture of servers which extend a distributed computing environment to implement these mobility management protocols.
This report describes our experience acquired when we restructured OODesigner, a computer aided softwareengineering (CASE) tool for object modeling techniques (OMT). We had developed the version 1.x of OODesigner dur...
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ISBN:
(纸本)0818683686
This report describes our experience acquired when we restructured OODesigner, a computer aided softwareengineering (CASE) tool for object modeling techniques (OMT). We had developed the version 1.x of OODesigner during 3 years since 1994. Although we had developed this version using OMT and C++, we recognized the potential maintenance problem that originated from the ill-designed class architecture. Thus we totally restructured the old version of OODesigner during 12 months, and obtained a new version that is much easier to maintain than the old one.
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