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Enhancing Reliability via Checkpointing in Cloud Computing Systems

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China Communications 2017年第7期14卷 108-117页

作者： Ao Zhou Qibo Sun Jinglin Li state key Laboratory of networking and {3. technology Beijing University of Posts and Telecommunications

Cloud computing is becoming an important solution for providing scalable computing resources via Internet. Because there are tens of thousands of nodes in data center, the probability of server failures is nontrivial. Therefore, it is a critical challenge to guarantee the service reliability. Fault-tolerance strategies, such as checkpoint, are commonly employed. Because of the failure of the edge switches, the checkpoint image may become inaccessible. Therefore, current checkpoint-based fault tolerance method cannot achieve the best effect. In this paper, we propose an optimal checkpoint method with edge switch failure-aware. The edge switch failure-aware checkpoint method includes two algorithms. The first algorithm employs the data center topology and communication characteristic for checkpoint image storage server selection. The second algorithm employs the checkpoint image storage characteristic as well as the data center topology to select the recovery server. Simulation experiments are performed to demonstrate the effectiveness of the proposed method.

关键词： cloud computing cloud service reliability fault tolerance data center network

On Effective Virtual Networks Interconnection

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China Communications 2016年第3期13卷 165-173页

作者： Huang Tao Huang Chengyuan Ma Ningning state key Laboratory of networking and {3. technology BUPTChina Beijing Advanced Innovation Center for Future lntemet technology Beijing 100876China

The network services today require extremely agile and mobile, however, the traditional IP infrastructures are so rigid that cannot fit services well. A way should be put forward to automate the network to improve responsiveness to change. SDN and network virtualization(NV) are two hottest approaches to make networking more automated and scalable to support virtualized and cloud environments. Network virtualization combines hardware and software network resources and network functionality into a single virtual network. SDN is created to simplify traffic management and achieve operational efficiencies by establish and exercising central control over packet forwarding. In this paper, we focus on the situation where SDN controller needs to connect two virtual networks temporarily. We put forward three algorithms to try to make this connection more effective and evaluate these three algorithms.

关键词： SDN network virtualization(VN) temporary connection

Practical conditions of signal space alignment for generalized MIMO Y channel

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Science China(Information Sciences) 2012年第10期55卷 2171-2182页

作者： SHE JiaJu 1,2,CHEN ShanZhi 1,2,HU Bo 1,WANG YingMin 2 & SU Xin 2 1 state key Laboratory of networking and {3. technology,Beijing University of Posts and Telecommunications,Beijing 100876,China 2 state key Laboratory of Wireless Mobile Communications,China Academy of Telecommunications technology,Beijing 100191,China 1. state key Laboratory of networking and {3. technology Beijing University of Posts and Telecommunications Beijing 100876 China2. State Key Laboratory of Wireless Mobile Communications China Academy of Telecommunications Technology Beijing 100191 China

This paper proposes a generalization for applications of signal space alignment(SSA) in a generalized multiple input multiple output(MIMO) Y channel with K(K 2) nodes and an intermediate *** on that generalization,a method is introduced to determine the practical conditions for *** first study the generalized MIMO Y channel model with general signal demands;then,the degrees of freedom(DoF) achieved are given and are proved using *** SSA could decrease the number of antennas at the relay,it places new restrictions on the numbers of antennas at the *** then introduce a method to compare the models with and without SSA network coding(SSA-NC),mainly from the perspective of the total number of antennas *** results show that if each node must be able to exchange signals with all others,the model with SSA will definitely use more antennas to supply the same DoF,when K > *** it is not necessary for every node to exchange signals with all others,the comparison can still be made by using the method introduced *** a result,the conditions under which SSA-NC is needed are presented.

关键词： Signal space alignment MIMO Y channel degrees of freedom number of antennas

Resource Allocation and User Association for HTTP Adaptive Streaming in Heterogeneous Cellular Networks with Small Cells

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China Communications 2016年第9期13卷 1-11页

作者： Jiang Liu state key Laboratory of networking and {3. technology Beijing University of Post and TelecommunicationsBeijing 100876China Department of Systems and Computer Engineering Carleton UniversityOttawaONCanada Beijing Advanced Innovation Center for Future Internet technology Beijing 100124China

Video streaming,especially hypertext transfer protocol based(HTTP) adaptive streaming(HAS) of video,has been expected to be a dominant application over mobile networks in the near future,which brings huge challenge for the mobile *** some works have been done for video streaming delivery in heterogeneous cellular networks,most of them focus on the video streaming scheduling or the caching strategy *** problem of joint user association and rate allocation to maximize the system utility while satisfying the requirement of the quality of experience of users is largely *** this paper,the problem of joint user association and rate allocation for HTTP adaptive streaming in heterogeneous cellular networks is studied,we model the optimization problem as a mixed integer programming *** to reduce the computational complexity,an optimal rate allocation using the Lagrangian dual method under the assumption of knowing user association for BSs is first *** we use the many-to-one matching model to analyze the user association problem,and the joint user association and rate allocation based on the distributed greedy matching algorithm is ***,extensive simulation results are illustrated to demonstrate the performance of the proposed scheme.

关键词： heterogeneous cellular networks user association rate allocation http adaptive streaming matching algorithm

Subsidence control and farmland conservation by solid backfilling mining technology

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中国有色金属学会会刊：英文版 2011年第S3期21卷 665-669页

作者： GUO Guang-li1, 2, FENG Wen-kai3. ZHA Jian-feng1, 2, 3. LIU Yuan-xu1, 2, WANG Qiang1, 2 1. key Laboratory for Land Environment and Disaster Monitoring of the state Bureau of Surveying and Mapping, China University of Mining and technology, Xuzhou 221116, China 2. Jiangsu key Laboratory of Resources and Environmental Information Engineering, China University of Mining and technology, Xuzhou 221116, China 3. state key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of technology, Chengdu 610059, China [a] key Laboratory for Land Environment and Disaster Monitoring of the state Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China [b] Jiangsu key Laboratory of Resources and Environmental Information Engineering China University of Mining and Technology Xuzhou 221116 China [c] state key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China

Solid backfilling mining technology, which decreases the height of fissure zone and caving zone, and alleviates the subsidence, is a new technology for farmland conservation. Based on the situation analysis of farmland destruction in mining area, three ways for farmland protection were proposed. In order to improve the feasibility of this technology, the limited filling materials should be used to increase resources recovery ratio, and then the surplus materials could be backfilled into goaf. An index, namely farmland conservation ability, was put forward to optimize the ways for farmland conservation. At last, the Wanbei coal mine was taken as a case for farmland conservation. It was shown that 3.40 t dull coal was substituted and 52 hm2 farmland was conserved by solid backfilling mining in this coal mine.

关键词： solid backfilling farmland conservation mining subsidence equivalent mining height

Mining subsidence control by solid backfilling under buildings

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中国有色金属学会会刊：英文版 2011年第S3期21卷 670-674页

作者： ZHA Jian-feng1, 2, 3. GUO Guang-li1, 2, FENG Wen-kai3. WANG Qiang1, 2 1. key Laboratory for Land Environment and Disaster Monitoring of the state Bureau of Surveying and Mapping, China University of Mining and technology, Xuzhou 221116, China 2. Jiangsu key Laboratory of Resources and Environmental Information Engineering, China University of Mining and technology, Xuzhou 221116, China 3. state key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of technology, Chengdu 610059, China [a] key Laboratory for Land Environment and Disaster Monitoring of the state Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China [b] Jiangsu key Laboratory of Resources and Environmental Information Engineering China University of Mining and Technology Xuzhou 221116 China [c] state key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China

Solid backfilling mining can reduce the buildings' damage caused by mining greatly. The reduction of subsidence value, the slow advancing speed and the subsidence caused by backfilling body compaction are the main reasons that solid backfilling mining velocity decreases significantly. Based on the research of mechanism, some principles on subsidence control of solid backfilling mining under buildings were proposed. The equivalent mining height was designed according to the fortification criteria of buildings and their attachment structures, which enables the ground movement and deformation caused by mining to be less than the corresponding fortification criteria.

关键词： solid backfilling mining subsidence control mining under buildings

On the construction of multi-output Boolean functions with optimal algebraic immunity

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Science China(Information Sciences) 2012年第7期55卷 1617-1623页

作者： ZHANG Jie 1,2 ,SONG ShouChao 1 ,DU Jiao 2,3.& WEN QiaoYan 2 1 School of Science,Beijing University of Posts and Telecommunications,Beijing 100876,China 2 state key Laboratory of networking and {3. technology,Beijing University of Posts and Telecommunications,Beijing 100876,China 3.Department of Mathematics,Xinxiang University,Xinxiang 453.03.China 1. School of Science Beijing University of Posts and Telecommunications Beijing 100876 China2. State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China3. Department of Mathematics Xinxiang University Xinxiang 453003 China

In this paper,we show a construction of multi-output Boolean functions with optimal algebraic ***,the relationship between the algebraic immunity of a multi-output Boolean function and those of its component functions is *** show that all the component functions,together with their nonzero linear combination,of the multi-output Boolean functions achieved by this construction have optimal algebraic immunity simultaneously.

关键词： algebraic immunity Boolean functions algebraic attacks annihilators

Simulation study of phase retrieval for hard X-ray in-line phase contrast imaging

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Science China(Physics,Mechanics & Astronomy) 2005年第4期48卷 450-458页

作者： YU Bin1,2, PENG Xiang1,2, TIAN Jindong1, NIU Hanben1, DIAO Luhong3.& LI Hua3.1. key Laboratory of Optoelectronic Devices and Systems of Ministry of Education, Institute of Optoelec- tronics, Shenzhen University, Shenzhen 518060, China 2. state key Laboratory of Precision Measuring {3. and Instruments, Tianjin University, Tianjin 3.0072,China 3. key Laboratory of Intelligent Information Processing, Institute of Computing {3., Chinese Academy of Sciences, Beijing 100080,China 1. key Laboratory of Optoelectronic Devices and Systems of Ministry of Education Institute of Optoelectronics Shenzhen University 518060 Shenzhen China 2. state key Laboratory of Precision Measuring technology and Instruments Tianjin University 300072 Tianjin China 3. key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences 100080 Beijing China

Two algorithms for the phase retrieval of hard X-ray in-line phase contrast imaging are presented. One is referred to as Iterative Angular Spectrum Algorithm (IASA) and the other is a hybrid algorithm that combines IASA with TIE (transport of intensity equation). The calculations of the algorithms are based on free space propagation of the angular spectrum. The new approaches are demonstrated with numerical simulations. Comparisons with other phase retrieval algorithms are also performed. It is shown that the phase retrieval method combining the IASA and TIE is a promising technique for the application of hard X-ray phase contrast imaging.

关键词： X-ray optics, phase contrast imaging, phase retrieval, angular spectrum, hard X-ray.

Secure Beamforming Design for SWIPT in Cooperative D2D Communications

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China Communications 2017年第1期14卷 20-33页

作者： Li Jiang Cheng Qin Xixi Zhang Hui Tian state key Laboratory of networking and {3. technology Beijing University of Posts and Telecommunicationsand Science and Technology on Information Transmission and Dissemination in Communication Networks LaboratoryBeijing100876China

In device-to-device(D2D) communications, device terminal relaying makes it possible for devices in a network to function as transmission relays for each other to enhance the spectral efficiency. In this paper we consider a cooperative D2D communication system with simultaneous wireless information and power transfer(SWIPT). The cooperative D2D communication scheme allows two nearby devices to communicate with each other in the licensed cellular bandwidth by assigning D2D transmitters as half-duplex(HD) relay to assists cellular downlink transmissions. In particular, we focus on secure information transmission for the cellular users when the idle D2D users are the potential eavesdroppers. We aim to design secure beamforming schemes to maximize the D2D users data rate while guaranteeing the secrecy rate requirements of the cellular users and the minimum required amounts of power transferred to the idle D2D users. To solve this non-convex problem, a semi-definite programming relaxation(SDR) approach is adopted to obtain the optimal solution. Furthermore, we propose two suboptimal secure beamforming schemes with low computational complexity for providing secure communication and efficient energy transfer. Simulation results demonstrate the superiority of our proposed scheme.

关键词： device-to-device(D2D) communications half-duplex relaying physical layer security secure beamforming simultaneous wireless information and power transfer