Mobile computing systems have many constraints such as low battery power low bandwidth, high mobility and lack of stable storage which are not presented in static distributed systems. In this paper we propose an effic...
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ISBN:
(纸本)0769524052
Mobile computing systems have many constraints such as low battery power low bandwidth, high mobility and lack of stable storage which are not presented in static distributed systems. In this paper we propose an efficient communication-induced checkpointing protocol for mobile computing systems. We also propose an asynchronous recovery protocol based on the checkpointing protocol. Mobile support stations control major parts of the checkpointing and recovery such as storing and tracing the checkpoints, requesting rollback and logging messages, so that mobile hosts do not incur much overhead. The recovery algorithm has no domino effect and a failed process needs to roll back to its latest checkpoint and request only a subset of the processes to rollback to a consistent checkpoint. Our recovery protocol uses selective message logging at the mobile support station to handle the messages lost due to rollback.
For the given multiple patterns and a text string, firstly, a perfect hash function is constructed, the patterns are transformed into the unique pairs of integer values in parallel by the perfect hash function, the co...
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ISBN:
(纸本)9780769534435
For the given multiple patterns and a text string, firstly, a perfect hash function is constructed, the patterns are transformed into the unique pairs of integer values in parallel by the perfect hash function, the corresponding integer values are stored in a global hash table, and a recursion expression for computing hash function value of the signatures of each sub-string of text is also proposed. Secondly based on divisible load principle, a linear programming model for the optimal text distribution strategy is created and a parallel approximate multi-pattern matching algorithm allowing one error is presented on the heterogeneous cluster system which processors have different computing speeds and distinct communication capabilities and different memory sizes by taking into account computation and communication startup time and using the assigned processor distribution order. The experimental results on the cluster system of heterogeneous personal computers show that the presented parallel algorithm is averagely 25% faster than that one using the even text distribution strategy, and it obtains a nearly linear speedup and good scalability.
This paper discusses a parallel genetic algorithm (GA) which focuses on the local operator for Traveling salesman problem (TSP). The local operator is a simple GA named as Local Genetic Algorithm (LGA). The LGA is com...
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ISBN:
(纸本)0769524052
This paper discusses a parallel genetic algorithm (GA) which focuses on the local operator for Traveling salesman problem (TSP). The local operator is a simple GA named as Local Genetic Algorithm (LGA). The LGA is combined to another GA named as Global Genetic Algorithm (GGA). It increases the computational time running a GA as a local operator in another one. To solve this problem, we build a parallel system based on our previous works for running the LGA to speed up the process. The results show that LGA improve the search quality significantly and it is more efficient running LGA with parallel system than single CPU.
A new secret-sharing-based e-auction scheme is proposed. distributed bid opening is employed to protect bid privacy. It can achieve all the desired properties for sealed-bid auctions at a reasonable cost. Moreover, at...
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Locomotive-track coupling dynamical simulation has made good achievements([1][2]). However, a problem, how to improve the simulating speed when visualization and dynamical computation are considered at the same time, ...
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ISBN:
(纸本)0780378407
Locomotive-track coupling dynamical simulation has made good achievements([1][2]). However, a problem, how to improve the simulating speed when visualization and dynamical computation are considered at the same time, is still not overcome. Here, based on existing success, we present a distributed COM technology, which is used to change the status of the present slow speed simulation. In this paper, at first, the locomotive-track dynamics system is modeled, a resolving formula is discussed, and visualization of the system is given, then the characteristic of the main integration resolving algorithm is analyzed, which is the reason of actuating the DCOM method. Secondly, we divide these resolving equations into several separated module, which is distributed in different resolving machine as a COM, and construct a distributedparallelcomputing environment, this method effectively reduces the computing load of the main computer and the computing speed is improved, which is the basement of real-time simulation such as virtual dynamical test of locomotive.
Efficient replica location in large-scale distributed systems is a challenging problem. In this paper, we propose a new decentralized replica location method to meet the requirement of replica location in such systems...
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Efficient replica location in large-scale distributed systems is a challenging problem. In this paper, we propose a new decentralized replica location method to meet the requirement of replica location in such systems. In our method each data object has a home node, which maintains the replica location information of the data object to accelerate the process of locating multiple replicas of the same data. A dynamic balancing technique which can adapt to the joining or departing of home nodes is proposed to spread global replica location information evenly on home nodes. Soft-state strategy is used to propagate update. Analysis and simulations show that our method can achieve low latency, good scalability, reliability, adaptability and is especially fit for the environments characterized by high query rates but low rates of nodes and network changes.
作者:
Xu, YFFudan Univ
Dept Comp & Informat Technol Shanghai 200433 Peoples R China
The function of digital library is not limited to information management now, hut also has more relationship with community. P2P networks are highly scalable platforms, which should be suitable for personal digital li...
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ISBN:
(纸本)0769524052
The function of digital library is not limited to information management now, hut also has more relationship with community. P2P networks are highly scalable platforms, which should be suitable for personal digital library, but the contradiction between efficiency and autonomy holds back their progress in applying them to DL. In this paper, we propose an autonomous flexible content addressable network (Flexible CAN), in which nodes can change their position freel. Flexible CAN has the advantages of both efficiency and autonomy. It can be used not only for information managing and retrieving, but also autonomic detect group of users with the same interest. Thus the group becomes a community, and users can share their resources and experiences conveniently.
The processing of three-dimensional (3-D) objects from 3-D digital image data is an important task in the image processing and the computer vision fields. The distance transform (DT) is extensively applied in the imag...
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ISBN:
(纸本)0780378407
The processing of three-dimensional (3-D) objects from 3-D digital image data is an important task in the image processing and the computer vision fields. The distance transform (DT) is extensively applied in the image processing and computer vision areas as a key operation. In a two or three-dimensional image array, the computation of distance transform (DT) is an important task, With the increasing application of 3D voxel images, it is useful to consider the distance transform of a 3D digital image array. In order to provide the efficient transform computations, parallelism is employed. We develop parallel algorithms for the three-dimensional Euclidean distance transform (3D-EDT) on the SIMD hypercube computer. The time complexity of our parallel algorithm is O{log(2) N} for an N x N x N image array using N-3 processors. A generalized parallel algorithm for the 3D-EDT is also proposed and it runs O((N/p)(3) log(N) + (N/p)(2) log(2) p) time for an N x N x N binary image array on the SIMD hypercube computer using p(3) PE's, where 1 less than or equal to p less than or equal to N.
distributed system monitor of heterogeneous environment is a very important problem in distributed system searching field. This paper describes an asynchronous event relation model, which constructs a hiberarchy event...
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ISBN:
(纸本)0769524052
distributed system monitor of heterogeneous environment is a very important problem in distributed system searching field. This paper describes an asynchronous event relation model, which constructs a hiberarchy event relation graph according to event equivalent relation, and event ordinal relation, and event independent relation, and event exclusive relation. According to event relation graph, asynchronous event transacting process determines which events will be transacted This model not only reduces numbers of asynchronous events transacted but also can reflect state of monitor object. The periodic method and asynchronous event relation model are compared with monitoring distributed system in this paper. By implementation, the model is efficient.
With the increasing popularity of shared-memory programming model, especially at the advent of multicore processors, applications need to become more concurrent to take advantage of the increased computational power p...
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