Recently, Cloud computing, as one of the hottest words in IT world, has drawn great attention. Many IT companies such as IBM, Google, Amazon, Microsoft, Yahoo and others vigorously develop cloud computing systems and ...
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In the relay-trading mode of wireless cognitive radio networks the secondary user (SU) can achieve a promised spectrum access opportunity by relaying for the primary user (PU). How to utilize the exchanged resource ef...
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Many recent applications involve processing and analyzing uncertain data. Recently, several research efforts have addressed answering skyline queries efficiently on massive uncertain datasets. However, the research la...
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Many recent applications involve processing and analyzing uncertain data. Recently, several research efforts have addressed answering skyline queries efficiently on massive uncertain datasets. However, the research lacks methods to compute these queries on uncertain data, where each dimension of the uncertain object is represented as an interval or an exact value. In this paper, we extensively study the problem of skyline query on these interval based uncertain objects, which has never been studied before. We first model the problem of querying the skylines on interval datasets. Typically, we address two efficient algorithms with I/O optimal for the conventional interval skyline queries and constrained interval skyline queries, respectively. Extensive experiments demonstrate the efficiency of all our proposed algorithms.
Botnets are threatening the Internet heavily, and more and more botnets are utilizing the P2P technology to build their C&C (Command and Control) mechanisms. Some research have been made to compare the resilience ...
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Botnets are threatening the Internet heavily, and more and more botnets are utilizing the P2P technology to build their C&C (Command and Control) mechanisms. Some research have been made to compare the resilience of structured P2P botnets and unstructured ones, against elimination of nodes, but the problem that which eliminating strategy is the best is rarely studied. In this paper, we proposed a new metric called the half point, to measure the effectiveness of different strategies. We also selected seven different eliminating strategies and compared them. Through extensive simulations, we find that RBC is the best eliminating strategy. Further analysis shows that for the strategy RBC, the average degree of nodes in the botnet have the most significant influence. The bigger the average degree is, the bigger the half point of RBC is, which implies that node eliminating may not be a reasonable choice for mitigating botnets with big average degree. Results of this paper can provide guidance for restraining structured P2P botnets.
Wireless interference does not necessarily result in the lost of all the information of the desired signal. In this paper, we study the signature allocation in wireless networks by exploiting the retained signal featu...
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ISBN:
(纸本)9781612846842
Wireless interference does not necessarily result in the lost of all the information of the desired signal. In this paper, we study the signature allocation in wireless networks by exploiting the retained signal feature under interference. The commonly used node signature includes MAC address and PN sequence. However, both of them take a lot of time to identify the signature when the network scale is large. We propose a novel signature allocation method based on a multi-hash policy, using a set of hash functions and a mapping-table to identify the signature. The proposed method decreases significantly both the signature identification complexity and the signature conflict probability. We implement the algorithm in GNU Radio and evaluate the performance in a testbed of three USRP nodes. The result shows that, under typical settings,
Open Source Forge (OSF) websites provide information on massive open source software projects, extracting these web data is important for open source research. Traditional extraction methods use string matching among ...
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Open Source Forge (OSF) websites provide information on massive open source software projects, extracting these web data is important for open source research. Traditional extraction methods use string matching among pages to detect page template, which is time-consuming. A recent work published in VLDB exploits redundant entities among websites to detect web page coordinates of these entities. The experiment gives good results when these coordinates are used for extracting other entities of the target site. However, OSF websites have few redundant project entities. This paper proposes a modified version of that redundancy-based method tailored for OSF websites, which relies on a similar yet weaker presumption that entity attributes are redundant rather than whole entities. Like the previous work, we also construct a seed database to detect web page coordinates of the redundancies, but all at the attribute-level. In addition, we apply attribute name verification to reduce false positives during extraction. The experiment result indicates that our approach is competent in extracting OSF websites, in which scenario the previous method can not be applied.
Software security is one of the most important aspects of software quality, but errors in programs are still inevitable. Despite the development of static and dynamic analysis, the useful but costly manual analysis is...
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Software security is one of the most important aspects of software quality, but errors in programs are still inevitable. Despite the development of static and dynamic analysis, the useful but costly manual analysis is still heavily used. In this paper, we propose a human computation game based software error detection mechanism. The purpose of our mechanism is to improve the effectiveness and efficiency of manual error detection. The framework includes four main steps: 1) get all suspicious error locations by static tools according to different security properties;2) slice the programs from each error location;3) construct games for each slice and show them to players;4) collect game information and generate the final error report. We evaluate our approach by instantiating it for detecting errors of buffer overflow. The results show that our technique is successful in practice.
Context situation, which means a snapshot of the status of the real world, is formed by integrating a large amount of contexts collected from various resources. How to get the context situation and use the situation t...
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Context situation, which means a snapshot of the status of the real world, is formed by integrating a large amount of contexts collected from various resources. How to get the context situation and use the situation to provide better services is a challenging issue. In this paper, we focused on this challenge on the basis of the mobile cloud computing architecture. An abstract model is proposed in this paper to uniformly collect the context and send them to cloud. A rule-based large-scale context aggregation algorithm is also proposed which utilizes the MapReduce computing paradigm. Finally, a large-scale context management framework based on the abstract model and the context aggregation algorithm is proposed, and a real-time traffic demo is implemented to verify the validity of the framework.
This paper evaluates the performance and efficiency of Imagine stream processor for scientific programs. It classifies scientific programs into three classes based on their computation to memory access ratios. Typical...
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As a complex, flexible and effective platform for network attacking, the botnet spreads widely in the Internet. Botnets can provide the botmasters with the ability to launch large-scale malicious activities such as sp...
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As a complex, flexible and effective platform for network attacking, the botnet spreads widely in the Internet. Botnets can provide the botmasters with the ability to launch large-scale malicious activities such as spamming and DDoS (distributed Denial of Service) attacks. Botnets are continuously bringing more and more severe threats, so that the study on botnets has already become one of the focuses in the field of network security. However, in recent years, some new developments of botnets are challenging the existing understanding on botnets. In this paper, according to the new conditions of botnets and the researches in existence, a definition of botnet is proposed based on the works of other researchers, taxonomies of botnets are introduced respectively from the views of network structure, dependency and delivery pattern of C&C (Command and Control) information. Then the techniques on detecting, measuring and restraining botnets are analyzed systematically. In the end, we give the evolution trends of botnets and the future research trends in this area.
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