检索结果-内蒙古大学图书馆

Block diagonal precoding based power allocation for coordinated multi-point transmission

Journal of Communications 2011年第7期6卷 524-528页

作者： Han, Jing Wang, Ping Liu, Fuqiang Zhu, Yin Broadband Wireless Communications and Multimedia Laboratory Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai China Shanghai Key Laboratory of Digital Media Processing and Transmission Shanghai China

This paper studies power allocation in coordinated multi-point (CoMP) transmission of 3GPP LTE-Advanced system with remote radio units(RRUs) power constraints. We apply block diagonal (BD) precoding to downlink transmission, and assume perfect knowledge of downlink channels and transmit messages at each transmit point. We propose a modified water-filling power (MWF) allocation algorithm in order to maximize the downlink sum capacity, at the same time the low complexity is achieved. The interior-point method is also used to solve the optimization problem. Simulations show that interior-point method converges after only a few iterative steps and the system capacity is near-optimal. As for complexity and power efficiency, MWF achieves a good compromise. © 2011 ACADEMY PUBLISHER.

关键词： Iterative methods

来源：评论

学校读者我要写书评

暂无评论

Fast adaptive interpolation filter algorithm for bi-predicted frame in video coding

Fast adaptive interpolation filter algorithm for bi-predicte...

引用

International Conference on Multimedia Technology

作者： Huichao Gao Feng Cen Weisheng Xu Key Laboratory of Embedded System and Service Computing Ministry of Education University of Tongji Shanghai China College of Electronics and Information Engineering University of Tongji Shanghai China

ISBN: (纸本)9781612847719

This paper proposes a novel adaptive interpolation filter (AIF) to reduce computational complexity and bit-rate of video coding. In the proposed AIF, the filter coefficients of B frames, which are predicted from those of adjacent P frames with a novel parabolic model, are unnecessary to transmit. Experimental results show that the coding complexity is reduced by 40.22% with no penalty on coding efficiency and 1.59% bit rate reduction is achieved at low bit-rate against conventional AIF.

关键词： Interpolation Wiener filter Adaptive filters Encoding Information filters Complexity theory

来源：评论

学校读者我要写书评

暂无评论

Trust reasoning and optimization based on associate petri net

引用

ICIC Express Letters 2011年第3期5卷 791-796页

作者： Fang, Xianwen Yan, Chungang Fan, Xiaoqin Yin, Zhixiang Department of Information and Computing Science Anhui University of Science and Technology No. 168 Shungengzhong Road Huainan 232001 China Key Lab of Embedded System and Service Computing Ministry of Education Tongji University No. 1239 Siping Road Shanghai 201804 China

Trust issue is an important problem both in social field and information field. At present, there are few methods considering the interaction behavior relativity between models which can judge the interaction influence, so the obtained trust value is imprecise and unreliable. In the paper, behavior-aware trust computation and reasoning methods based on Associate Petri net (APN) are presented, which use the APN reasoning and take the interaction relativity into account. Using Genetic Algorithm (GA) combined with the properties of APN, a trust optimization method is obtained. Theoretical analysis and experimental results indicate that the method owns both lower computation cost and lower error rate. © 2011 ISSN 1881-803X.

关键词： Genetic algorithms

来源：评论

学校读者我要写书评

暂无评论

Asymptotic bounds on lifetime of large scale clustering UWB sensor network

引用

Tien Tzu Hsueh Pao/Acta Electronica Sinica 2011年第10期39卷 2263-2268+2281页

作者： Xu, Juan Fang, Yu Xu, Hua-Jie School of Electronics and Information Engineering Tongji University Shanghai 200092 China Key Laboratory of Embedded System and Service Computing of the Ministry of Education Tongji University Shanghai 200092 China School of Computer and Electronic Information Guangxi University Nanning Guangxi 530004 China

Considering time hopping impulse radio ultra wide band (TH-IR UWB) sensor networks composed n sensor nodes which are placed according to a Poisson point process on a square and a Sink. The results demonstrate that the bounds on the lifetime of dense network increase with the increase of the number of nodes n, and that of extended network decrease with the increase of the number of nodes n. The results also indicate the bounds on the lifetime of clustering sensor networks is far more than that of non-clustering network, thus clustering can evidently improve network lifetime. Furthermore, the bounds on the lifetime of clustering TH-IR UWB sensor network which the nodes are distributed according to a Poisson point process are different from that of clustering network which the nodes are placed according to uniform distribution, thus the behavior of nodes deploying can remarkably affect the lifetime bound.

关键词： Energy dissipation

来源：评论

学校读者我要写书评

暂无评论

Adaptive social network construction using Gaussian mixture model

引用

Information Technology Journal 2011年第12期10卷 2252-2259页

作者： Guo, Xin Xiang, Yang Chen, Qian Wei, Wei Department of Computer Science and Technology School of Electronic and Information Engineering Tongji University Shanghai 201804 China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 200092 China

A Social network graph shows social interactions and relationships between individuals in a specific social environment, which is very helpful for analyzing social relationships, activities, structures, etc. The author quantized the strengths of social objects' relationships in social environment using an improved vector space model. Gaussian mixture model was employed to set the threshold for identifying social relationships adaptively and divide social subgroups automatically. According to the threshold, social network graph would be constructed based on performance measures. It is concluded that hidden social relationships can be discovered effectively by using this approach which is very flexible and adaptive for dynamic information feedback mechanism. © 2011 Asian Network for Scientific Information.

关键词： Gaussian distribution

来源：评论

学校读者我要写书评

暂无评论

Upper bounds on lifetime of ordinary clustering ultra wide band sensor networks

引用

Ruan Jian Xue Bao/Journal of Software 2011年第2期22卷 313-322页

作者： Xu, Juan Hong, Yong-Fa Wang, Cheng Bai, Xing-Zhen College of Electronics and Information Engineering Tongji University Shanghai 200092 China Key Laboratory of Embedded System and Service Computing of the Ministry of Education Tongji University Shanghai 200092 China College of Information Science and Engineering Shandong University of Science and Technology Qingdao 266510 China

This paper considers the time hopping impulse radio ultra wide band (TH-IR UWB) sensor networks, with n sensor nodes uniformly and independently located on a square and a Sink. The upper bounds on the lifetime of ordinary clustering dense and extended TH-IR UWB sensor networks are derived respectively. For ordinary clustering networks, the cluster head aggregates data from the nodes within its own cluster, and relays data to other cluster heads. The results indicate that the upper bounds on the lifetime of ordinary clustering dense TH-IR UWB are in proportion with the node density (or the number of nodes), while the upper bounds on the lifetime of extended networks are inversely proportional to the size of the deployment area (or the number of nodes). The results also reveal that the upper bound on the lifetime of dense network in the ideal case are longer than those of the static network by a factor of (n/log n)1/2, and the upper bound on the lifetime of extended network in the ideal case are longer than those of the static network by a factor of (λn/log(λn))1/2. Therefore, sensor nodes, or the Sink moving randomly in the square, can improve the lifetime of ordinary clustering TH-IR UWB sensor network. © 2011 ISCAS.

关键词： Energy dissipation

来源：评论

学校读者我要写书评

暂无评论

Web service Composition Techniques in a Health Care service Platform

Web Service Composition Techniques in a Health Care Service ...

引用

IEEE International Conference on Web services (ICWS)

作者： Pengwei Wang Zhijun Ding Changjun Jiang Mengchu Zhou Key Laboratory of Embedded System and Service Computing Ministry of Education University of Tongji Shanghai China Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA

The information technology has been recognized as one of the most important means to improve health care and curb its ever-increasing cost. However, existing efforts mainly focus on informatization of hospitals or medical institutions within organizations, and few are directly oriented to individuals. The strong demand for various health services from customers calls for the creation of powerful individual-oriented personalized health care service systems. Web service composition (WSC) and related technologies can greatly help one build such systems. This paper aims to present a newly developed platform called a Public oriented Health care Information service Platform (PHISP) and several novel WSC techniques that are used to build it. Among them include WSC techniques that can well support branch and parallel structures.

关键词： Biomedical imaging service oriented architecture Diseases Computer architecture Hospitals

来源：评论

学校读者我要写书评

暂无评论

A top-down algorithm for finding principal curves from complex patterns data

引用

ICIC Express Letters 2011年第3期5卷 797-802页

作者： Zhang, Hongyun Miao, Duoqian Xie, Chen Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University No. 1239 Siping Road Shanghai 201804 China School of Electronic and Information Engineering Tongji University No. 1239 Siping Road Shanghai 201804 China

Principal curves are a well established tool in data analysis and processing, but for complex pattern data with high curvature, high dispersion and self-intersecting, such as spiral-shaped curves, existing methods did not perform well. To solve the problem, a top-down strategy is introduced to extract principal curves from complex pattern data. Firstly, the thinning-based method is used to create rudimentary principal graph of data set, and then merging the contiguous vertices. Finally, the fitting-and-smoothing step introduced by Kégl is improved to optimize the principal graph, and Kégl's restructuring step is used to rectify imperfections of principal graph. This algorithm has been not only tested on simulated data sets but also applied to image skeletonization. Experimental results indicate the effectiveness of the proposed method on finding principal curves from complex pattern data sets. © 2011 ISSN 1881-803X.

关键词： Image enhancement

来源：评论

学校读者我要写书评

暂无评论

Solving the maximum planar subgraph problem using a two-part permutation encoding genetic approach

引用

ICIC Express Letters 2011年第11期5卷 4107-4113页

作者： Li, Sheng Chen, Huiqin Gao, Shangce Tang, Zheng Graduate School of Innovation Life Science University of Toyama Gofuku 930-8555 Toyama-shi Japan Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University No. 1239 Siping Road Shanghai 200092 China

Genetic algorithms (GAs) have been shown to be very useful in a variety of search and optimization problems. In this paper, we present a new genetic algorithm for the maximum planar subgraph problem (MPSP). Previous studies investigated solving the MPSP with genetic algorithms using standard bit string chromosomes. This paper proposes a new two-part permutation encoding with a greedy heuristic decoding to represent the chromosomes. The first part represents the ordering of the edges in the graph, while the second part deals with the starting vertex based on which a vertex sequence can be determined. Computational testing shows the new approach produces better solutions than previous techniques. © 2011 ICIC International.

关键词： Chromosomes

来源：评论

学校读者我要写书评

暂无评论

Reader Activation Scheduling in Multi-reader RFID systems: A Study of General Case

Reader Activation Scheduling in Multi-reader RFID Systems: A...

引用

International Symposium on Parallel and Distributed Processing (IPDPS)

作者： Shaojie Tang Cheng Wang Xiang-Yang Li Changjun Jiang Department of Computer Science Illinois Institute of Technology Chicago IL USA Key Laboratory of Embedded System and Service Computing Ministry of Education Shanghai China Department of Computer Science University of Tongji Shanghai China

Radio frequency identification (RFID) is a technology where a reader device can "sense'' the presence of a close by object by reading a tag device attached to the object. To guarantee the coverage quality, multiple RFID readers can be deployed in the given region. In this paper, we consider the problem of activation schedule for readers in a multi-reader environment. In particular, we try to design a schedule for readers to maximize the number of served tags per time-slot while avoiding various interferences. We first develop a centralized algorithm under the assumption that different readers may have different interference and interrogation radius. Next, we propose a novel algorithm which does not need any location information of the readers. Finally, we extend the previous algorithm in distributed manner in order to suit the case where no central entity exists. We conduct extensive simulations to study the performances of our proposed algorithm. And our evaluation results corroborate our theoretical analysis.

关键词： Interference Radiofrequency identification Schedules Scheduling Processor scheduling Geometry Algorithm design and analysis

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：