摘要：
Peer-to-peer (P2P) network provides an efficient way for resource sharing. However, due to lacking centralized control and the anonymity of peers, security becomes a serious problem in P2P network, especially in P2P file-sharing network, which heavily restricts the development of P2P file-sharing systems. Trust models have been widely used in estimating the trustworthiness of peers in P2P file-sharing systems in order to minimize threats of such open communities. However, current P2P trust models almost measure whether a peer is good or bad only by a trust value, which results in low efficiency in resisting the attacks of malicious peers. Additionally, there are more and more free-riders in P2P systems. This paper proposes a new trust model based on a 5-tuple to deal with these two problems, which integrate the set of uses, trust, experience, sharing files and heterogeneity levels. The simulation experiments are carried out to evaluate the performance and validity of this trust model in a P2P file-sharing system. The result proves that it is effective to prevent malicious act and encourage peers to share there resources in P2P network.
作者：
Feng, Hong-Cai;Yuan, Xiao-Juan;Ming, Wei;Yuan, Cao
期刊：
Proceedings of the International Conference on E-Business and E-Government, ICEE 2010,2010年:1647-1650
通讯作者：
Feng, H.-C.(fenghc@whpu.edu.cn)
作者机构：
[Feng, Hong-Cai; Yuan, Cao; Ming, Wei; Yuan, Xiao-Juan] Department of Computer and Information Engineering, Wuhan Polytechnic University, Wuhan, China
关键词：
high performace cloud;storage cloud;compute cloud;distributed data application
摘要：
This paper presents a new high performance cloud framework that support simplified data parallel applications. and descripes the design and implementation of it. this cloud implements stream processing paradigm over clusters of computers, either within single data center or across wide arer. Unlike MapReduce, this Cloud's stream processing paradigm is simpler, more straightforward, and reaches better performance in certain cases. The experimental results show this cloud is more straighforword, simpler to use, and it is about twice as fast as Hadoop.
摘要：
In order to maximize the network lifetime for target coverage, we propose a distributed optimum coverage algorithm for point target in wireless sensor networks. In this paper, we first present a 1-hop local target coverage problem, next analyze the critical restraint of this problem and introduced the definition of key target, then designed an energy utility function, last established an adaptive adjustment mechanism of the waiting time. Measurement results show that the new algorithm extends 20% longer network lifetime, has good scalability and stability, and a lower computational and communication complexity.
摘要：
This paper studies the utility-maximization resource allocation problem for soft QoS traffic in wireless networks, which demands certain amount of bandwidth for normal operation but allows some flexibility. With deviations to the known approaches and solutions, we propose a novel utility optimization model, which bounds the bandwidth allocation of each flow around its desired value and allows certain flexibility. We theoretically analyse this model and give a complete procedure to obtain the solution.
摘要：
In order to maximize the network lifetime for target coverage, we propose a Heuristic Greedy Optimum Coverage Algorithm (HG-OCA). In HG-OCA, we first design a network model in which power supplies of sensor nodes follow a normal distribution. Next, we analyze energy model of target coverage, educe three rules to reduce network scale, present the concept of the key target and the prior coverage of key target. Moreover, we choose sensor with most energy utility as active sensor. In the end, we present HG-OCA to extend network lifetime, based on minimizing energy consumption of key target and maximizing energy efficiency of sensor node. Measurement results show that the new algorithm could increase 80% longer network lifetime and achieve more adaptability and stability.
摘要：
In traditional vocal tract length normalization (VTLN) method, the details of the differences of spectral among speakers can not be modeled, because only a simple vocal tract length factor is regarded as the absolutely indicator of the speaker specific attribute, according to the assumption of lossless multi-tube vocal tract model. In this paper, the piece-wise frequency warping function is adopted to describe the speaker specific character in detail. With an appropriate partition of frequency axis, the differences of spectral can be removed well. Due to the model-independent warping function, this method is proved to be a quite fast adaptation technique, and especially suitable for the unsupervised adaptation.
