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Improvement of rotation matrix based differential limited feedback with DFT codebook and its application in CoMP environment

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Journal of Communications 2014年第6期9卷 498-505页

作者： Zhu, Yin Ji, Yusheng Wang, Ping Liu, Fuqiang Broadband Wireless Communications and Multimedia Laboratory Key Laboratory of Embedded System and Service Computing supported by Ministry of Education Tongji University Shanghai 201804 China National Institute of Informatics Tokyo Japan

Recently, exploiting the temporal correlation of slowly varied multiple input multiple output (MIMO) channels to further improve the system performance or the feedback efficient in MIMO wireless communication systems with limited feedback has been investigated in many papers. Among them, T. Kim et al. proposed a rotation matrix based differential feedback scheme which is shown to have good performance with regard to the system throughput for spatial multiplexing MIMO systems. Although the rotation matrix codebook and the precoding codebook in their scheme are optimally constructed, they are not fit for a practical system due to the structure constraints. In this paper, we propose to replace the optimal codebook in the rotation matrix based differential feedback scheme with discrete Fourier transform (DFT) structured codebook, and propose a search-based method to decrease the performance degradation induced by the un-optimality of the DFT codebook. In addition, the modified algorithm is also applied to a per-cell codebook based coordinated multi-point (CoMP) transmission system to verify its applicability to different MIMO scenarios. Simulation results show the effectiveness of our modified scheme. © 2014 Engineering and Technology Publishing.

关键词： Discrete Fourier transforms

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

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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

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Distributed collaborative vehicle tracking in embedded smart camera networks 12

Distributed collaborative vehicle tracking in embedded smart...

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12th IEEE International Conference on Dependable, Autonomic and Secure computing, DASC 2014

作者： Zhang, Yaying Lu, Xiuqing Ye, Chen Key Laboratory on Embedded System and Service Computing College of Electronics and Information Engineering Tongji University Shanghai China

ISBN: (纸本)9781479950799

A vehicle tracking mode based on dynamic roles is proposed in the smart camera networks. The tracking for a specific vehicle is organized collaboratively and automatically in smart camera network. The tracking is completed autonomously by smart cameras in a distributed manner. The decentralized control mode can effectively decrease the working pressure of server system, reduce the requirements of network bandwidth for real-time video transmission, and make the system flexible and fault-tolerant. An information transmission mechanism is also presented in the smart camera network to ensure the collaborative tracking. Finally, a demo system for vehicle tracking in intelligent traffic surveillance system is implemented to verify the proposed methods. © 2014 IEEE.

关键词： Image communication systems

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Extended and improved slicing technologies for Petri nets

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High Technology Letters 2013年第1期19卷 98-104页

作者： Yu, Wangyang Yan, Chungang Ding, Zhijun Fang, Xianwen Department of Computer Science and Technology Tongji University Shanghai 201804 China Key Lab. of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 201804 China

Petri net is an important tool to model and analyze concurrent systems, but Petri net models are frequently large and complex, and difficult to understand and modify. Slicing is a technique to remove unnecessary parts with respect to a criterion for analyzing programs, and has been widely used in specification level for model reduction, but researches on slicing of Petri nets are still limited. According to the idea of program slicing, this paper extends slicing technologies of Petri nets to four kinds of slices, including backward static slice, backward dynamic slice, forward static slice and forward dynamic slice. Based on the structure properties, the algorithms of obtaining two kinds of static slice are constructed. Then, a new method of slicing backward dynamic slice is proposed based on local reachability graph which can locally reflect the dynamic properties of Petri nets. At last, forward dynamic slice can be obtained through the reachability marking graph under a special marking. The algorithms can be used to reduce the size of Petri net, which can provide the basic technical support for simplifying the complexity of formal verification and analysis. © by HIGH TECHNOLOGY LETTERS PRESS.

关键词： Petri nets

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Modeling and monitoring of online shopping business processes based on system behavior patterns

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Journal of Computational Information systems 2013年第12期9卷 4691-4698页

作者： Yu, Wangyang Yan, Chungang Ding, Zhijun Zhong, Junzhu Department of Computer Science and Technology Tongji University Shanghai 201804 China Key Lab. of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 201804 China

Online shopping integrating third-party payment platforms (TPPs) has rapidly developed recently. The integration leads to new security problems derived from complex interactions among Application Programming Interfaces (APIs), and the detection of such defects in application-level is costly and difficult. To deal with these security issues at the online stages, this paper presents a framework of modeling and monitoring online shopping business processes from the point of legal behavior patterns. We present Online Shopping Net (OSN) to model the normal business process, and make it as the legal behavior pattern used to monitor system behaviors. Then, a monitor based on OSN is constructed. The system behaviors beyond the legal behavior pattern would be alarmed and blocked. It is a novel attempt to guarantee the security of online shopping from the point of behaviors and online monitoring. Using the active defense tactics, we can effectively prevent the illegal behaviors of the users at application-level instead of constantly fixing bugs of applications. As a case study, we simulate an e-commerce site and a TPP, and the monitor can effectively prevent the malicious behaviors appearing recently. © 2013 by Binary Information Press.

关键词： Application programming interfaces (API)

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A New MPI Parallel computing Environment Based on Fibre-channel Token-Routing Network for Materials Simulation Research

A New MPI Parallel Computing Environment Based on Fibre-chan...

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International Conference on Advanced Materials in Microwaves and Optics (AMMO 2011)

作者： Zeng, Xiaohui Liu, Dongsheng Luo, Wenlang Fu, Lixin School of Electronics and Information Engineering Jinggangshan University China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University China

ISBN: (纸本)9783037852736

In order to apply our high efficiency fibre-channel token-routing network (shortened as FC-TR network) to the field of materials simulation research, a new MPI parallel computing environment is proposed and designed, and independently developed a parallel programming environment FC-TR-MPI based on FC-TR network. In FC-TR-MPI, a new method was applied to point-to-point communication that the network communications between processes in the same computing node were changed into memory operations;moreover, according to the underlying software and hardware features of FC-TR network, new algorithms were proposed to optimize the communication performance of some collective communications. Experimental results show that, compared with ScaMPI parallel programming environment, FC-TR-MPI has a higher parallel efficiency and speedup.

关键词： MPI parallel computing environment fibre-channel materials simulation

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Associating semantic sensor web with domain ontology: The way to obtain meaningful sensor data

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International Journal of u- and e- service, Science and Technology 2014年第5期7卷 271-282页

作者： Ji, Chaoqun Liu, Jin Wang, Xiaofeng College of Info. Engineering Shanghai Maritime University Shanghai China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai China

To realize the sharing and reuse of sensor data and improve interoperability, semantic sensor web(SSW)is proposed to add semantics information to existing sensor networksby utilizing domain, spatial and temporal anthologies and other related semantic *** these is seldom research on how to fully utilize the sensor data through a semantic way such as domain ontology based inference. This paperpresents stateofthe art of SSWin various aspects, and proposesthe method to associate data from semantic sensor web with domain ontology to realize the communication between different domain ontologies and SSW. In addition, this paperalso proposes a new calculation method of semantic similarity amongdifferent entities in different ontology. Experiments show that this method can effectively find the similar entitiesandrealize the knowledge sharing and ontologies reuse. © 2014 SERSC.

关键词： Ontology

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Multi-sensor based perception network for vehicle driving assistance

Multi-sensor based perception network for vehicle driving as...

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2009 2nd International Congress on Image and Signal Processing, CISP'09

作者： Jun, Han Fuqiang, Liu Zhipeng, Li Shanshan, Zhang Key Laboratory of Embedded System and Service Computing Tongji University Shanghai China Tongji University China College of Electronics and Information Engineering Tongji China

ISBN: (纸本)9781424441310

In this paper, a multi-sensor based perception network for vehicle driving assistance is described. The network could reconstruct the 3D real world from the data obtained by the sensors, recognize dangerous occasions in advance and give the driver a suggestion or warning to prevent from the accident. Vehicle driving assistance is a research area which requires high accuracy and precision. The purpose of this perception network is to make up for the weakness of one sensor by means of the advantages of other sensors in the network. We will discuss the details of our adopted solutions, and present some real experimental results. ©2009 IEEE.

关键词： Vehicles

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Covariance free incremental principal component analysis with exact mean update

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Journal of Computational Information systems 2013年第16期9卷 6703-6710页

作者： Zeng, Xueqiang Li, Guozheng The Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 200092 China Computer Center Nanchang University Nanchang 330029 China Department of Control Science and Engineering Tongji University Shanghai 201804 China

Incremental feature extraction is an essential data preprocessing technique for large-scale and streaming data mining. Among various covariance matrix-free Incremental Principal Component Analysis (IPCA) methods, Candid Covariance-free Incremental Principal Component Analysis (CCIPCA) is a state-of-the art algorithm. Since the training samples are required to be centred, CCIPCA applies an approximate centric alignment on the input data, where only the current sample is correctly centred and all historical data are not updated properly. In this paper, we propose a novel centred incremental principal component analysis algorithm with exact historical mean update, where not only the current sample is centred, but also all historical data are updated by the current mean correctly. Compared to CCIPCA, the proposed method converges more quickly, and the performance improvement is especially obvious when the data's inherent covariance is not stable. The experiments on real streaming dataset show that the proposed method is much superior to CCIPCA in convergence speed. © 2013 Binary Information Press.

关键词： Principal component analysis

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A credible individual behavior profiling method for online payment fraud detection 21

A credible individual behavior profiling method for online p...

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4th International Conference on Data Storage and Data Engineering, DSDE 2021

作者： Cui, Jipeng Yan, Chungang Wang, Cheng Key Laboratory of the Ministry of Education for Embedded System and Service Computing Department of Computer Science and Engineering Tongji University China

ISBN: (纸本)9781450389303

Online payment fraud detection relies on a credible characterization of individual behaviors. Existing individual behavior profiling methods have three problems in credibility. Firstly, they solely regard users as individuals to model and fail to credibly characterize the whole behavior patterns of transactions. Secondly, they cannot make full use of the general information among similar individuals due to the heterogeneity of transaction attributes. Thirdly, they are not capable of utilizing the label information of transactions credibly. Faced with these challenges, we propose a credible method for individual behavior profiling that consists of two steps. The first step is the construction of the credible individual behavior profiling framework. To begin with, the concept of individuals is generalized and the credible transaction description is given. Afterwards, based on the co-occurrence information of transaction attributes, the credible behavior condition is defined to set a limit to individual behavior patterns. The second step is the implementation of the framework. For this purpose, the original fraud detection problem is transformed into a pseudo-recommender system problem with a co-occurrence mapping process. In order to guarantee the credible behavior constraint, a credible recommendation algorithm is designed to collaboratively restore both the ranking and rating information of the pseudo-rating matrices. Besides, an embedding based approach is adopted to parameterize the proposed model. Experiments on an online payment transaction dataset demonstrate the effectiveness of our proposed method. © 2021 ACM.

关键词： Crime

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