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Simulation of moving boundary of the reaction shaft in a flash smelting furnace

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Journal of Central South university 2001年第3期13卷 213-218页

作者： chen Zhuo 1,MEI Chi 1,chen Hong-rong 1,MO Jiao 2.(1 Institute on Simulation and Optimization of Pyro-installation, Central Sout h {2., Changsha 410083, china 2.Science School, beijing {2. of posts and Telecommunications, beijing 1 1. Institute on Simulation and Optimization of Pyro-installation Central South University 410083 Changsha China 2. Science School Beijing University of Posts and Telecommunications 100876 Beijing China

As to solve the online monitoring of the inner temperatur e and freezing profile of the reaction shaft of flash smelting furnace, simulation of the wall in the reaction shaft in a flash smelting furnace was made through numerical computation. The computational results are very near the data got in s ite. The error of the moving boundary is approximately 3%, and that of the tempe rature is less than 5%. It is proved that the simulation software is applicable for practice to monitor the temperature and moving boundary inside the hearth on line. Based on a large number of the data computed, the relation between the cha nge of the moving boundary and inner temperature is summarized, and the great in fluence of the cooling system on the forming and stability of the moving boundar y inside the hearth is emphasized, which provide the theoretical bases for optim izing the flash smelting operation.

关键词： flash smelting furnace moving boundary numerical computation simulation

QoS-guaranteed multi-relay selection and power allocation optimization in cooperative systems

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The Journal of china Universities of posts and Telecommunications 2010年第6期17卷 25-31页

作者： chen Dan,JI Hong,LI Xi,LI Yi College of Information and Communication Engineering,beijing {2. of posts and Telecommunications,beijing 100876,china [a] College of Information Communication Engineering Beijing University of Posts Telecommunications Beijing 100876 China

This paper investigates the relay selection and power allocation problem in multi-user based cooperative networks,where intermediate relay nodes help source forward information to destination using decode-and-forward （DF） relaying protocol. Specifically,we propose a novel multi-relay nodes selection strategy taking both instantaneous channel state information （I-CSI） and residual energy into consideration,by which ＇emergence＇ diversity gain can be achieved and the imbalance of resource utilization can be overcome. Besides,using Largangian dual-primal decomposition and subgradient projection approach,an optimal power allocation algorithm at source and cooperative relay nodes is presented with the constraints of each user＇s individual quality of service （QoS） requirements and system total transmit power. Theoretical analysis and simulation results demonstrate that the proposed scheme can significantly improve energy efficiency,while guaranteeing a good balance between achievable data rate and average network lifetime with relatively low implementation complexity.

关键词： cooperative diversity relay selection resource allocation Lagrangian dual-primal decomposition subgradient projection

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 Switching Technology,beijing {2. 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 Switching 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

User-perceived e-mail service QoS parameters and measurement

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The Journal of china Universities of posts and Telecommunications 2010年第3期17卷 85-90页

作者： LI Yong-zhi , LIU Feng, LEI Zhen-ming, chen Ling School of Information and Communication Engineering, beijing {2. of posts and Telecommunications, beijing 100876, china [a] School of Information Communication Engineering Beijing University of Posts Telecommunications Beijing 100876 China

A group of quality of service （QoS） parameters of electronic mail （e-mail） traffic are proposed from users＇ perspective. These parameters cover three fields： delay, throughput and usability. Concept and algorithm of each parameter are presented and its effect on user perceptions is described. In order to evaluate the effectiveness of these parameters, an active measurement system is implemented. Measured results show that the group of QoS parameters we proposed can be used to get a comprehensive view of user-perceived e-mail service QoS.

关键词： user perceptions e-mail service QoS active measurement

Automatic composition of information-providing web services based on query rewriting

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Science china(Information Sciences) 2012年第11期55卷 2428-2444页

作者： ZHAO WenFeng,LIU ChuanChang & chen JunLiang State Key Laboratory of Networking and Switching Technology,beijing {2. of posts and Telecommunications,beijing 100876,china 1. State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

Compared with normal web services,information-providing services have unique features that have seldom been considered in existing research on the automatic composition of web *** this paper,we present a simple,yet well-formed,semantic-based capability model for information-providing web services,which can express such features as not modifying the world state and not requiring all input/output parameters to be supplemented with class information as *** then present a corresponding automatic composition method derived from a query rewriting algorithm,MiniCon,used in the data integration *** method adequately utilizes previous features,enables primitive semantic reasoning,and can generate executable BPEL scripts *** of the method is complementary to traditional search-based *** on a typical type of problem show that the method is usable in practice.

关键词： web services automatic composition query rewriting data integration ontology semantic web

Valiant load-balancing and regionalized routing scheme

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The Journal of china Universities of posts and Telecommunications 2010年第3期17卷 78-84页

作者： YANG Fan , WANG Zhen-kai, chen Jian-ya, LIU Yun-jie School of Information and Communication Engineering, beijing {2. of posts and Telecommunications, beijing 100876, china [b] School of Information Communication Engineering Beijing University of Posts Telecommunications Beijing 100876 China

Valiant load-balancing （VLB） routing scheme has drawbacks of logical full mesh, intermediate nodes （networks） and single application of topology. To address these, the authors propose a novel routing scheme called regionalized VLB （R-VLB）. Based on ideas of VLB and regionalizing, R-VLB divides the nodes of backbone network into several regions whose topological structure is logical full mesh, and combines shortest-path routing scheme and VLB routing scheme. R-VLB also achieves logical local interconnection, non-central nodes （networks） and a wide range of application of topology. The relevant theoretical analysis and simulation results show that R-VLB achieve good throughput and failure performance close to that of VLB, and it even has better delay performance. R-VLB provides an idea for the application of VLB routing scheme.

关键词： routing scheme VLB topology backbone network

Construction of LDPC codes over GF(q) with modified progressive edge growth

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The Journal of china Universities of posts and Telecommunications 2009年第5期16卷 103-106,113页

作者： chen Xin , MEN Ai-dong, YANG Bo, QUAN Zi-yi School of Information and Communication Engineering, beijing {2. of posts and Telecommunications, beijing 100876, china [a]School of Information and Communication Engineering beijing university of {2. and Telecommunications beijing 100876 china

A parity check matrix construction method for constructing a low-density parity-check （LDPC） codes over GF（q）（q〉2. based on the modified progressive edge growth （PEG） algorithm is introduced. First, the nonzero locations of the parity check matrix are selected using the PEG algorithm. Then the nonzero elements are defined by avoiding the definition of subcode. A proof is given to show the good minimum distance property of constructed GF（q）-LDPC codes. Simulations are also presented to illustrate the good error performance of the designed codes.

关键词： LDPC codes over GF(q) progressive edge growth large minimum distance

Context-aware end-to-end QoS diagnosis and quantitative guarantee based on Bayesian network

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The Journal of china Universities of posts and Telecommunications 2010年第6期17卷 106-112页

作者： LIN Xiang-tao,CHNEG Bo,chen Jun-liang,QIAO Xiu-quan State Key Laboratory of Networking and Switching Technology,beijing {2. of posts and Telecommunications,beijing 100876,china [a] State Key Laboratory of Networking Switching Technology Beijing University of Posts Telecommunications Beijing 100876 China

To support quality of service （QoS） management on current Internet working with best effort,we bring forth a systematic approach for end-to-end QoS diagnosis and quantitative guarantee. For QoS diagnosis,we take contexts of a service into consideration in a comprehensive way that is realized by exploiting causal relationships between a QoS metric and its contexts with the help of Bayesian network （BN） structure learning. Context discretization algorithm and node ordering algorithm are proposed to facilitate BN structure learning. The QoS metric is diagnosed to be causally related to its causal contexts,and the QoS metric can be quantitatively guaranteed by its causal contexts. For quantitative QoS guarantee,those causal relationships are first modeled quantitatively by BN parameter learning. Then,the QoS metric is guaranteed to certain value with a probability given its causal contexts tuned to suitable values,that is,quantitative QoS guarantee is reached. Simulations with three sequential stages：context discretization,QoS diagnosis and quantitative QoS guarantee,on a peer-to-peer （P2.） network,are discussed and our approach is validated to be effective.

关键词： context context discretization QoS qualitative diagnosis QoS quantitative guarantee Bayesian network

Relaying strategy for peer-to-peer content distribution based on genetic algorithm

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The Journal of china Universities of posts and Telecommunications 2010年第2期17卷 85-91页

作者： HE Qian ,MENG Xiang-wu,SHANG Yan-lei,chen Jun-liang State Key Laboratory of Networking and Switching Technology,beijing {2. of posts and Telecommunications,beijing 100876,china [a] State Key Laboratory of Networking Switching Technology Beijing University of Posts Telecommunications Beijing 100876 China

This article proposes a cooperative relaying strategy to efficiently utilize the relaying resources of Interact service providers （ISPs）, speedup distribution and save server bandwidth costs. ISPs cooperatively relay for each other, and peers assist in distributing and fetching the content as near as possible. Base on the fluid model, a constrained model is derived to get optimized global distribution performance in the channel-based system with limited relaying resources. The multi-objectives of the model are minimizing the average distribution time and the distribution time of the slowest channel. Genetic algorithm （GA） is designed to solve the optimization problem. The relaying strategy based on GA can be run periodically to update the allocation policy of ISPs. The distribution performance of the relaying strategy is analyzed in the experiments and results show that GA can provide proper solutions for various network topologies.

关键词： content distribution peer-to-peer genetic algorithm cooperative relaying resource allocation