Owing to the rapidly growing interests and excitement in distributedcomputing and grid-enabled applications, the facilitating middleware layer has become a center of attention in recent years. At the same time, rapid...
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Owing to the rapidly growing interests and excitement in distributedcomputing and grid-enabled applications, the facilitating middleware layer has become a center of attention in recent years. At the same time, rapid advances in networking technologies such as the resilient packet ring (RPR) have evolved to carry all kinds of information including data, voice, multimedia and now, grid applications. However, little studies have been made to discover the interactions between grid middleware and the network layer. This paper therefore investigates the degree of which grid middleware design takes advantage of the underlying networking resources and features.
A series of problems arises with the emergence and fast development of grid. Among all the problems, one of them is how to smoothly connect heterogeneous grid platforms. There are a number of ways to solve this proble...
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A series of problems arises with the emergence and fast development of grid. Among all the problems, one of them is how to smoothly connect heterogeneous grid platforms. There are a number of ways to solve this problem and the relatively more efficient one is using ontology. Based on this method, we focus on alleviating semantic inconsistency of various platforms and designing a novel ontology. This ontology is depicted by resource description framework (RDF) and transacted by adapters. Finally, we test our method and analyze its performance.
Dynamic composition of protocol features allows applications to establish connections with custom communication characteristics. Automatically computing possible compositions and checking given compositions requires a...
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Dynamic composition of protocol features allows applications to establish connections with custom communication characteristics. Automatically computing possible compositions and checking given compositions requires a common framework for expressing application needs, service features, and system characteristics. In this paper, we present such a framework that is based on situation calculus. We show that the automated composition problem can be reduced to an AI planning problem. We further illustrate the effectiveness of this approach with several examples.
A campus-wide grid and cluster infrastructure using the Rocks clustering software is established. The infrastructure, namely Grid-Enabled Research Network and Info-structure of University of Malaya (GERANIUM), compris...
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A campus-wide grid and cluster infrastructure using the Rocks clustering software is established. The infrastructure, namely Grid-Enabled Research Network and Info-structure of University of Malaya (GERANIUM), comprises five distinct clusters located at different faculties and institutes. In this paper, the GERANIUM topology and architecture are presented, and issues and experiences concerned are discussed.
A Mobile Ad Hoc Network (MANET) is becoming a practical platform for pervasive social networking. People chat with each other via MANET for instant social activities. How to help mobile users to build up trust in such...
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A Mobile Ad Hoc Network (MANET) is becoming a practical platform for pervasive social networking. People chat with each other via MANET for instant social activities. How to help mobile users to build up trust in such an environment is becoming an important issue. We develop a reputation system for pervasive social networking. We implement it by applying Nokia N900 smartphones as MANET nodes based on a distributed energy-efficient social networking platform. Our system can indicate each user's local reputation during chatting. It also provides detailed reputation information and supports on-chat voting and afterwards voting. This demo paper introduces the system design and its principal functionalities.
Many private BitTorrent communities employ Sharing Ratio Enforcement (SRE) schemes to incentivize users to contribute. It has been demonstrated that communities that adopt SRE are greatly oversupplied, i.e., they have...
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Most existing collaborative applications on the Web require centralized servers for storing shared data and relaying communication messages among browsers. This means that users of these applications must fully trust ...
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Most existing collaborative applications on the Web require centralized servers for storing shared data and relaying communication messages among browsers. This means that users of these applications must fully trust centralized servers that hold and relay potentially sensitive and important data. Furthermore, users can lose access to their data if centralized servers go out of *** paper proposes building a distributed Web browser as a platform for Web-based collaborative applications to address these problems with centralized servers. A distributed browser consists of multiple browser nodes. Each node looks like a regular Web browser, is operated by a single user, but works together with other nodes. An application of the distributed browser runs across multiple nodes, and can make use of resources in both a local node and remote nodes. Multiple users can use a single application together. The distributed browser provides authenticated and secure inter-node communications for applications. This paper describes an implementation of a distributed browser, called Subspace. Subspace uses an instant messaging system, Skype, to perform user authentication and secure com- munication among browser nodes. Reusing the overlay network and social features of Skype makes the implementation of Subspace extremely simple. Several applications on Subspace including simple collaborative browsing and comment sharing have been developed. These implementations demonstrate that Subspace provides useful facilities utilized as a platform for developing Web-based collaborative applications.
In recent years, most Web 2.0/3.0 applications have been built on top of distributed systems which allow data to be modeled as distributed Ordered Tables (DOTs) such as Apache HBase. To analyze the stored data, SQL-li...
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Wireless low-power embedded devices are populating indoor environments, where everyday activities drastically impact communication. We explore a statistical approach to identify changes to the communication links stat...
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ISBN:
(纸本)9781450323642
Wireless low-power embedded devices are populating indoor environments, where everyday activities drastically impact communication. We explore a statistical approach to identify changes to the communication links state during system operation. The long-term behavior of the link RSSI is modeled with a normal distribution and compared against the model of the most recent measurements. A Welch's t-Test is then employed to identify whether the short-term and longterm link evolutions stem from the same distribution. Upon significant divergence, the long-term model is updated and a significant change in the underlying communication state is inferred. We investigate this technique to efficiently store a compressed fingerprint of the evolution of communication. Considering the memory constraints of low-power embedded systems, this approach allows to gather extensive information on the behavior of communication directly from the deployed network. This fingerprint could then be used to replay the network dynamics in simulation. We implemented the introduced techniques to prove their feasibility. In controlled experiments, we evaluate the reactivity and sensitivity of the approach to changes in the environment, as well as the accuracy of the resulting channel fingerprint. Copyright 2013 ACM.
The LDPC can provide multiple rates without employing more parity check matrices through the using of Rate Compatible strategy, in which the idea of puncturing is used to get codes at higher rates. This paper mainly f...
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The LDPC can provide multiple rates without employing more parity check matrices through the using of Rate Compatible strategy, in which the idea of puncturing is used to get codes at higher rates. This paper mainly focused on Blocktype LDPC, for which three different puncturing algorithms are shown. One is the original scheme of puncturing based on the recovery step. Another one is proposed by directly using the former on Base check matrix. Besides, the idea of puncturing distribution on systematical B-LDPC also performs well. These puncturing schemes are analyzed and compared in the text, and based on the result, new puncturing schemes for B-LDPC in IEEE 802.16e standard are proposed.
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