We first introduce a simple distance-vector protocol for routing in networks having unidirectional links. The protocol can be seen as an adaptation for these networks of the strategy as used in the popular RIP protoco...
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We first introduce a simple distance-vector protocol for routing in networks having unidirectional links. The protocol can be seen as an adaptation for these networks of the strategy as used in the popular RIP protocol. The protocol comprises two main algorithms, one for collecting "from" information, and the other one for generating and propagating "to" information. However, the traditional RIP approach has been a "busy" one because of the periodic sending of routing information even after the network has reached a stable state. We make further improvements on the simple protocol to get a message-thrifty variant. A routing information message is sent only when there is a change to the topology or when a link changes cost and only those affected entries need to be sent around.
This paper presents a visual approach to the representation and validation of multimedia document structures specified in XML and transformation of one structure to another. The underlying theory of our approach is a ...
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ISBN:
(纸本)0780371984
This paper presents a visual approach to the representation and validation of multimedia document structures specified in XML and transformation of one structure to another. The underlying theory of our approach is a context-sensitive graph grammar formalism. The paper demonstrates the conciseness and expressiveness of the graph grammar formalism. An example XML structure is provided and its graph grammar representation, validation and transformation to a multimedia representation are presented.
A very inexpensive receive-only satellite receiver can receive high bandwidth traffic from a feeder. Therefore the connection between the feeder and the receiver is uni-directional. The existing routing protocols, suc...
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A very inexpensive receive-only satellite receiver can receive high bandwidth traffic from a feeder. Therefore the connection between the feeder and the receiver is uni-directional. The existing routing protocols, such as Link-state and Distance-Vector, are designed on the premise that any links are bidirectional and they cannot handle the uni-directional links. In this paper,a dynamic multicast routing protocol is proposed, which can handle uni-directional networks. This protocol can also adapt to the dynamic change of the topology of the network and has good scalability. A formal description of the protocol by Petri net is given. Liveness, deadlock free and other properties of the protocol are proved.
A mass of heterogeneous, distributed and dynamic information on the World Wide Web (the Web) has resulted in 'information overload'. It's an important and urgent research issue to provide users with effec...
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A mass of heterogeneous, distributed and dynamic information on the World Wide Web (the Web) has resulted in 'information overload'. It's an important and urgent research issue to provide users with effective information retrieval service on the Web. Web search engines attempt to solve this problem, yet their effect is far from satisfying. In this paper, a distributed and cooperative strategy for information retrieval on the Web is proposed to substitute the centralized mode adopted by the current search engines. Then a new information retrieval system model IRSM is presented, which supports the retrieval of metadata about Web documents and uses Z39.50 standard protocol to unify the heterogeneous interfaces of. different systems. Based on that, a distributed and cooperative information retrieval framework, called DCIRF, is designed to help users in fast and effective information retrieval on the Web.
The data dependence analysis is a hard problem, particularly in the presence of data structures similar to the pointer. The inheritance and the polymorphism in object-oriented languages provide program design and soft...
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Synchronization is the major processing task during multimedia presentation, which defines the time relation between multimedia objects. There are many synchronization specification methods, and each has different adv...
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Synchronization is the major processing task during multimedia presentation, which defines the time relation between multimedia objects. There are many synchronization specification methods, and each has different advantages and disadvantages. Those methods work well for the simple and specific synchronization case, but when considering large complex multimedia presentation, there lacks an effective method to deal with the complex time relation. In this paper, a synchronization point based specification method (SPM) is proposed, and based on it, a static and dynamic validation mechanism for the synchronization relation is given. In SPM, the synchronization relation is defined in synchronization points (SP). Multimedia presentation control is based on SP's status during presentation. According to the order of SPs, SPM gives the static and dynamic validation algorithm, which can avoid the conflict relation between SPs. SPM gives a way to define the nondetermined synchronization relation between multimedia objects, and proposes static and dynamic validation mechanisms for complex synchronization control. This synchronization point based mechanism can extend the capability of synchronization definition and control in a multimedia system.
For real-time systems, UML sequence diagrams describe interactions among objects, which show scenarios of the system behaviour. A simple UML sequence diagram describes exactly one scenario. For describing multiple sce...
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For real-time systems, UML sequence diagrams describe interactions among objects, which show scenarios of the system behaviour. A simple UML sequence diagram describes exactly one scenario. For describing multiple scenarios and specifying real-time systems, we need to consider the compositions of UML sequence diagrams. In this paper, we introduce high-level graphs to describe compositions of UML sequence diagrams, and develop an algorithm for checking them for timing inconsistencies.
In this paper, we describe the design and implementation of a portable run-time system for GOP, a graph-oriented programming framework aiming at providing high-bevel abstractions for configuring and programming cooper...
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ISBN:
(纸本)0769509363
In this paper, we describe the design and implementation of a portable run-time system for GOP, a graph-oriented programming framework aiming at providing high-bevel abstractions for configuring and programming cooperative parallel processes. The runtime system provides an interface with a library of programming primitives to the low-level facilities required to support graph-oriented communications and synchronization. The implementation is on top of the Parallel Virtual Machine (PVM) in a local area network of Sun workstations. Issues related to the implementation of graph operations in a distributed environment are discussed. Performance of the runtime system is evaluated by estimating the overheads associated with using GOP primitives as opposed to PVM.
In this paper, the relationship between the second order typed - calculus 2 and its higher order version is discussed . A purely syntactic proof of the conservativity of over 2 is given.
In this paper, the relationship between the second order typed - calculus 2 and its higher order version is discussed . A purely syntactic proof of the conservativity of over 2 is given.
JAPS is an automatic parallelizing system based on JAVA running on NOW. It implements the automatic process from dependence analysis to parallel execution. The current version of JAPS can exploit functional parallelis...
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JAPS is an automatic parallelizing system based on JAVA running on NOW. It implements the automatic process from dependence analysis to parallel execution. The current version of JAPS can exploit functional parallelism and the detection of data parallelism will be incorporated in the new version, which is underway. The framework and key techniques of JAPS are presented. Specific topics discussed are task partitioning, summary information collection, data dependence analysis, pre-scheduling and dynamic scheduling, etc.
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