In distributed application domains where data change rapidly, it is often desirable for programs to obtain the latest available data values to achieve accurate computations. Example applications are financial services...
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In distributed application domains where data change rapidly, it is often desirable for programs to obtain the latest available data values to achieve accurate computations. Example applications are financial services and network management. Such data are logically shared by a network of programs. Unlike data in traditional databases, rapidly changing data are usually not lockable by (client) programs and it is crucial to the computations to access their values in a timely manner. In these application domains, a typical program usually performs computations based on recently available data values obtained from the network. However, these data values may be inconsistent or obsolete, since the real data are external to the system and may change more rapidly than can be reflected by their copies within the system. Decision making based on such inaccurate computations can lead to substantial penalties. In this paper, we propose an approach to delaying data value retrieval until needed in distributed programming, considering data and configuration change rapidly. this approach offers the advantage of obtaining more recent data values, resulting in more accurate computations and decision making.< >
Instruction-level parallelism in a single stream of code for non-numerical applications has been the subject of many recent researches. this work extends the analysis to symbolic applications described with logic prog...
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ISBN:
(纸本)9780818652806
Instruction-level parallelism in a single stream of code for non-numerical applications has been the subject of many recent researches. this work extends the analysis to symbolic applications described with logic programming. In particular, the authors analyze the effects on performance of speculative execution, memory alias disambiguation, renaming and flow prediction. the obtained results indicate that one can reach a sustained parallelism of 4 (comparable with imperative languages), withthe proper optimizations. the authors also show a comparison between static and dynamic scheduled approaches, outlining the conditions under which a dynamic solution can reach substantial improvements over a static one. In this way, they point out some important optimizations and parameters of a dynamic scheduling approach, indicating a guideline for future architectural implementations.< >
Predicting the performance of parallelapplications is a difficult but important problem. Better (more useful) performance predictions tend to require greater detail in analysis and measurements. Our goal is to be abl...
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Practical Prolog programs usually coniatn extra-logical features like cuts, side-effects, and database manipulating predicates. In order to exploit implicit parallelism from real applications a parallel logic programm...
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the symposium materials contain 118 papers on new developments in parallelprocessing. Algorithms, architectures, mapping/scheduling, applications, special-purpose architectures, interconnection networks, software, an...
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ISBN:
(纸本)0818626720
the symposium materials contain 118 papers on new developments in parallelprocessing. Algorithms, architectures, mapping/scheduling, applications, special-purpose architectures, interconnection networks, software, and distributed systems are among the main topics covered.
Petri nets are a versatile tool for modeling and analyzing parallel and distributed computing systems. However, state explosion is a major impediment to their analysis and practical applications. To cope withthis pro...
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ISBN:
(纸本)0818626720
Petri nets are a versatile tool for modeling and analyzing parallel and distributed computing systems. However, state explosion is a major impediment to their analysis and practical applications. To cope withthis problem, this paper proposes a method for constructing hierarchically organized state space (HOSS) of a bounded Petri net. Using the HOSS, we obtain necessary and sufficient conditions for reachability and deadlock, and algorithms to test if a given state (marking) is reachable from the initial state and if there is a deadlock state (a state with no successor states).
Nonreplicated shared data of distributedapplications is optimally allocated to pre-specified multilevel memory partitions at the sites of a heterogeneous multicomputer network to minimize a weighted combination of sy...
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ISBN:
(纸本)0818626720
Nonreplicated shared data of distributedapplications is optimally allocated to pre-specified multilevel memory partitions at the sites of a heterogeneous multicomputer network to minimize a weighted combination of systemwide mean time delay performance and mean communication cost per access request. Greedy and fast optimization algorithms are presented for nonqueueing lightly-loaded as well as heavily-loaded multiqueue system models with channel, I/O, and memory hierarchy queues. Extensions to data exhibiting nonuniform access demand rates and distinct query and update statistics are presented.
the Vesicular Dataflow (VDF) model is presented in the paper. the VDF model has been formulated to introduce a way of storing and retrieving information and hence to reduce the main drawback of the basic DF model. Tok...
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ISBN:
(纸本)0818626720
the Vesicular Dataflow (VDF) model is presented in the paper. the VDF model has been formulated to introduce a way of storing and retrieving information and hence to reduce the main drawback of the basic DF model. Tokens can be stored in vesicles in the VDF model and then distributed in non-deterministic way. State-dependent computations and global variables can be expressed in the dataflow manner. Informal definition of the VDF model and some simple applications are covered by the paper.
Aroma simplifies the task of parallelizing large applications on multicomputers by providing applications with a shared object space. Aroma supports both traditional monolithic objects and aggregate object that can be...
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ISBN:
(纸本)0818626720
Aroma simplifies the task of parallelizing large applications on multicomputers by providing applications with a shared object space. Aroma supports both traditional monolithic objects and aggregate object that can be partitioned across multiple nodes. Aggregate objects support data parallelism efficiently. An Aroma program consists of tasks that operate on shared objects. Task typically execute on the node on which their input data is located, thus minimizing communication. Shared data objects have synchronization properties associated withthem, making it possible to parallelize a large class of applications without using explicit locks and condition variables. In this paper, we present and justify the Aroma language features, and give examples of Aroma programs. Aroma has been implemented on the Nectar multicomputer and we give performance results for several applications.
A method is described for remotely sensed image segmentation based on the integration of edge detection and region growing approaches. the method is designed for full exploitation of parallelprocessing. the initial e...
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