检索结果-内蒙古大学图书馆

5th International Workshop on Multiple Access Communications, MACOM 2012

作者： Shen, Hu Lv, Shaohe Sun, Yanqiang Dong, Xuan Wang, Xiaodong Zhou, Xingming National Key Laboratory of Parallel and Distributed Processing National University of Defense Technology Changsha 410073 China Institute of Network Information and Security National University of Defense Technology Changsha 410073 China

ISBN: (纸本)9783642349751

In recent WLAN standards (such as IEEE 802.11n), MIMO (Multiple Input Multiple Output) is deployed to provide high data transmission rate. It is however challenging to efficiently share the channel resources among different stations/users. In this paper, we study the MAC protocol in heterogeneous MIMO-based WLAN to effectively exploit the capability of concurrent transmission. We propose a novel subcarrier encoding method, which uses frequency signatures to perform the control message exchange between the AP and multiple stations simultaneously. Afterwards, a MAC protocol, HT-MIMO MAC, is presented to support concurrent transmission in both the uplink and downlink directions. HT-MIMO MAC supports link adaptation and is completely compatible with legacy stations. We evaluate the performance of the HT-MIMO MAC protocol and find that it outperforms the existing 802.11 MAC protocol with SU-MIMO and the downlink MU-MIMO MAC protocol in [9] with a remarkable throughput gains up to 86%. © 2012 Springer-Verlag.

关键词： MIMO systems

来源：评论

学校读者我要写书评

暂无评论

Inducing taxonomy from tags: An agglomerative hierarchical clustering framework

Inducing taxonomy from tags: An agglomerative hierarchical c...

引用

8th International Conference on Advanced Data Mining and Applications, ADMA 2012

作者： Li, Xiang Wang, Huaimin Yin, Gang Wang, Tao Yang, Cheng Yu, Yue Tang, Dengqing National Laboratory for Parallel and Distributed Processing School of Computer Science National University of Defense Technology Changsha China College of Mechatronics Engineering and Automation National University of Defense Technology Changsha China

ISBN: (纸本)9783642355264

By amassing 'wisdom of the crowd', social tagging systems draw more and more academic attention in interpreting Internet folk knowledge. In order to uncover their hidden semantics, several researches have attempted to induce an ontology-like taxonomy from tags. As far as we know, these methods all need to compute an overall or relative generality for each tag, which is difficult and error-prone. In this paper, we propose an agglomerative hierarchical clustering framework which relies only on how similar every two tags are. We enhance our framework by integrating it with a topic model to capture thematic correlations among tags. By experimenting on a designated online tagging system, we show that our method can disclose new semantic structures that supplement the output of previous approaches. Finally, we demonstrate the effectiveness of our method with quantitative evaluations. © Springer-Verlag Berlin Heidelberg 2012.

关键词： Taxonomies

来源：评论

学校读者我要写书评

暂无评论

Topology-aware deployment of scientific applications in cloud computing

Topology-aware deployment of scientific applications in clou...

引用

2012 IEEE 5th International Conference on Cloud Computing, CLOUD 2012

作者： Fan, Pei Chen, Zhenbang Wang, Ji Zheng, Zibin Lyu, Michael R. National Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha 410073 China Dept. of Computer Science and Engineering Chinese University of Hong Kong Hong Kong Hong Kong

ISBN: (纸本)9780769547558

Nowadays, more and more scientific applications are moving to cloud computing. The optimal deployment of scientific applications is critical for providing good services to users. Scientific applications are usually topology-aware applications. Therefore, considering the topology of a scientific application during the development will benefit the performance of the application. However, it is challenging to automatically discover and make use of the communication pattern of a scientific application while deploying the application on cloud. To attack this challenge, in this paper, we propose a framework to discover the communication topology of a scientific application by pre-execution and multi-scale graph clustering, based on which the deployment can be optimized. Comprehensive experiments are conducted by employing a well-known MPI benchmark and comparing the performance of our method with those of other methods. The experimental results show the effectiveness of our topology-aware deployment method. © 2012 IEEE.

关键词： Cloud computing

来源：评论

学校读者我要写书评

暂无评论

A malicious code detection method based on statistical analysis

A malicious code detection method based on statistical analy...

引用

2012 9th International Conference on Fuzzy Systems and Knowledge Discovery, FSKD 2012

作者： Wu, Yunlong Chen, Chen Wang, Huiquan Zhou, Jie Xu, Xinhai National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha Hunan 410073 China School of Computer National University of Defense Technology Changsha Hunan 410073 China

ISBN: (纸本)9781467300223

The malicious code detection based on behaviors has proved effective. But there are high false positives and high false negatives when using this method. Because the behaviors are always out-of-order and redundant. To solve these problems, this paper proposes a detection method based on statistical analysis. Firstly, this method uses association rules to sort out the behaviors, and then we can get the integrated and accurate behavior sequences. Secondly, by using the association algorithm we can pick up the signatures of behavior sequences. In addition, this method can detect the signatures to judge the threat based on statistical analysis. Experimental results indicate that it can reduce both the false positives and the false negatives effectively. © 2012 IEEE.

关键词： Statistical methods

来源：评论

学校读者我要写书评

暂无评论

Research on malicious code detection based on least-squares estimation

Research on malicious code detection based on least-squares ...

引用

2012 International Conference on Computer Science and Electronics Engineering, ICCSEE 2012

作者： Wu, Yunlong Chen, Chen Wang, Huiquan Xu, Xinhai Zhou, Jie National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha Hunan 410073 China School of Computer National University of Defense Technology Changsha Hunan 410073 China

ISBN: (纸本)9780769546476

Malicious code detection based on behaviors is the development direction of anti-virus techniques. However, the current detection methods based on this theory expose several problems such as the unclearness of behavior sequence analysis and the high false negatives. For this situation, this paper proposes a malicious code detection method based on least-squares estimation. In this method, it correlates program behaviors with time and subject-object, and then constitutes an accurate and complete behavior sequence. It can provide a preprocessing method for the subsequent detection. In order to improve the accuracy and intelligence of malicious code detection, we introduce the concept of expert subjective degree. By modeling malicious samples based on least-squares estimation we can train the Expert Subjective Degree Vector (ESDV) and simulate experts to judge the threat values of malicious codes. Experiments show that this method is more accurate than the current ways to detect the malicious codes which execute themselves in sub-period and sub-process ways, so it can be used as an effective complement of the current anti-virus software. © 2012 IEEE.

关键词： Codes (symbols)

来源：评论

学校读者我要写书评

暂无评论

A Multi-Hash Based Signature Allocation Method in Wireless Network

A Multi-Hash Based Signature Allocation Method in Wireless N...

引用

International Conference on Wireless Communications, Networking and Mobile Computing (WiCom)

作者： Xuan Dong Xiaodong Wang Shaohe Lv Quan Liu Hu Shen Wenping Liu Xingming Zhou National Laboratory of Parallel and Distributed Processing National University of Defense Technology Changsha China

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,

关键词： Wireless networks Interference Media Access Protocol Resource management Heuristic algorithms Algorithm design and analysis

来源：评论

学校读者我要写书评

暂无评论

Exploiting Attribute Redundancy in Extracting Open Source Forge Websites

Exploiting Attribute Redundancy in Extracting Open Source Fo...

引用

International Conference on Cyber-Enabled distributed Computing and Knowledge Discovery, CyberC

作者： Xiang Li Yanxu Zhu Gang Yin Tao Wang Huaimin Wang National Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha China

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.

关键词： Redundancy HTML Databases Licenses Data mining Measurement

来源：评论

学校读者我要写书评

暂无评论

Game-based software errors detection

引用

Advances in Information Sciences and Service Sciences 2012年第15期4卷 426-433页

作者： Chen, Jie National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha 410073 China

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.

关键词： Error detection

来源：评论

学校读者我要写书评

暂无评论

parallel Implementation of the Slope One Algorithm for Collaborative Filtering

Parallel Implementation of the Slope One Algorithm for Colla...

引用

Panhellenic Conference on Informatics (PCI)

作者： Efthalia Karydi Konstantinos G. Margaritis Parallel and Distributed Processing Laboratory Department of Applied Informatics University of Macedonia Thessaloniki Greece

Recommender systems are mechanisms that filter information and predict a user's preference to an item. parallel implementations of recommender systems improve scalability issues and can be applied to internet-based companies having considerable impact on their profits. This paper implements two parallel versions of the collaborative filtering algorithm Slope One, which has advantages such as its efficiency and the ability to update data dynamically. The first presented version is parallely implemented with the use of the OpenMP API and its performance is evaluated on a multi-core system. The second is an hybrid approach using both OpenMP and MPI and its performance is evaluated in an homogeneous and an heterogeneous cluster. Experiments proved that the multithreaded version is 9,5 times faster than the sequential algorithm.

关键词： Prediction algorithms Collaboration Clustering algorithms Recommender systems Instruction sets Message systems Arrays

来源：评论

学校读者我要写书评

暂无评论

Cooperative spectrum sharing in relay-trading mode: A fairness view

Cooperative spectrum sharing in relay-trading mode: A fairne...

引用

4th International Conference on Cyber-Enabled distributed Computing and Knowledge Discovery, CyberC 2012

作者： Liu, Lixia Hu, Gang Xu, Ming Peng, Yuxing National Key Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha 410073 China Department of Networks Engineering School of Computer National University of Defense Technology Changsha 410073 China

ISBN: (纸本)9780769548104

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 efficiently and fairly is an interesting and practical problem. In this paper we proposed a cooperative spectrum sharing strategy (RT-CSS) for the relay-trading mode from the fairness view. The cooperative SUs are gathered in a cooperative sharing group (CSG), and contribution metric (CM) is proposed to measure each CSG member's contribution to CSG as well as benefit from CSG. The adjustment of CM can guarantee the fairness and efficiency of spectrum sharing. The numerical simulation shows that RT-CSS can achieve better performance than the sense-uncooperative mode. © 2012 IEEE.

关键词： Cognitive radio

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：