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Equation based rate control scheme for video streaming over wireless channels with link level ARQ

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2006年第10期7卷 1702-1708页

作者： ZHU Xiao-liang YANG Zong-kai DU Xu CHENG Wen-qing Department of Electronics ＆ Information Engineering Huazhong University of Science ＆ Technology Wuhan 430074 China

Equation based TCP-friendly rate control (TFRC) protocol has been proposed to support video streaming applications. In order to improve TFRC performance in wireless channels, the link level automatic repeat request (ARQ) scheme is usually deployed. However, ARQ cannot ensure strict delay guarantees, especially over multihop links. This paper introduces a theoretical model to deduce an equation for packet size adjustment in transport layer to minimize retransmission delay by taking into con- sideration the causative reasons inducing retransmission in link layer. An enhanced TFRC (ETFRC) scheme is proposed inte- grating TFRC with variable packet size policy. Simulation results demonstrate that higher goodput, lower packet loss rate (PLR), lower frame transmission delay and jitter with good fairness can be achieved by our proposed mechanism.

关键词： TFRC Video streaming Wireless channels Automatic repeat request (ARQ) Rate control

Synthesis of acetals and ketals catalyzed by tungstosilicic acid supported on active carbon

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Journal of Zhejiang University-science B(Biomedicine & Biotechnology) 2005年第5期6卷 373-377页

作者：杨水金杜心贤贺兰孙聚堂 Department of Chemistry and Environmental Engineering Hubei Normal University Huangshi 435002 China School of Chemistry and Molecular sciences Wuhan University Wuhan 430072 China

Catalytic activity of activated carbon supported tungstosilicic acidin synthesizing 2-methyl-2-ethoxycarbonylmethyl- 1,3-dioxolane, 2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, cyclohexanone ethylene ketal, cyclohexanone 1,2-propa- nediol ketal, butanone ethylene ketal, butanone 1,2-propanediol ketal, 2-phenyl-1,3-dioxolane, 4-methyl-2-phenyl-1,3-dioxolane, 2-propyl-1,3-dioxolane, 4-methyl-2-propyl-1,3-dioxolane was reported. It has been demonstrated that activated carbon supported tungstosilicic acid is an excellent catalyst. Various factors involved in these reactions were investigated. The optimum conditions found were: molar ratio of aldehyde/ketone to glycol is 1/1.5, mass ratio of the catalyst used to the reactants is 1.0%, and reaction time is 1.0 h. Under these conditions, the yield of 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane is 61.5%, of 2,4-dimethyl- 2-ethoxycarbonylmethyl-1,3-dioxolane is 69.1%, of cyclohexanone ethylene ketal is 74.6%, of cyclohexanone 1,2-propanediol ketal is 80.1%, of butanone ethylene ketal is 69.5%, of butanone 1,2-propanediol ketal is 78.5%, of 2-phenyl-1,3-dioxolane is 56.7%, of 4-methyl-2-phenyl-1,3-dioxolane is 86.2%, of 2-propyl-1,3-dioxolane is 87.5%, of 4-methyl-2-propyl-1,3-dioxolane is 87.9%.

关键词： Tungstosilicic acid Aceta Ketal Active carbon Catalysis

Structure formation of entanglement entropy in a system of two superconducting qubits coupled with an LC-resonator

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Chinese Physics B 2011年第8期20卷 39-46页

作者：葛国勤覃翠尹淼黄勇华 School of Physics Huazhong University of Science and Technology

This paper investigates theoretically the evolutions of the entanglement entropy of a system of two coupled-charge- qubits interacting with an LC-resonator. It is found that when the initial states of the two qubits are prepared in a given superposition excited state, the evolution of the von Neumann entropy of the system depends significantly on the coupling strength between the two Josephson charge qubits. With the variation of the coupling strength, the evolution of the entanglement entropy of the system forms some structures, especially the periodically bistable properties, which are the first discovered for such a system to our knowledge. It is found that the relative entropy entanglement of the system is also sensitive to the variation of the coupling strength between the two charge qubits, some novel ＇collective oscillations＇ of the relative entropy are found for the system.

关键词： superconducting quantum circuits evolutions of entanglement entropy structure forma-tion

QoS-aware multicast routing protocol for Ad hoc networks

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Journal of Systems Engineering and Electronics 2006年第2期17卷 417-422页

作者： Sun Baolin Li Layuan School of Computer science and Technology Wuhan Univ. of Technology Wuhan 430063. P. R. China Dept. of Mathematics and Physics Wuhan Univ. of Science and Engineering Wuhan 430073. P. R. China

Ad hoe wireless networks consist of mobile nodes interconnected by multihop communication paths. Unlike conventional wireless networks, ad hoc networks have no fixed network infrastructure or administrative support. Due to bandwidth constraint and dynamic topology of mobile ad hoc networks, supporting Quality of Service （QoS） is an inherently complex, difficult issue and very important research issue. MAODV （Multicast Ad hoc Ondemand Distance Vector） routing protocol provides fast and efficient route establishment between mobile nodes that need to communicate with each other. MAODV has minimal control overhead and route acquisition latency. In addition to unicast routing, MAODV supports multicast and broadcast as well. The multicast routing problem with multiple QoS constraints, which may deal with the delay, bandwidth and packet loss measurements is discussed, and a network model for researching the ad hoc network QoS multicast routing problem is described. It presents a complete solution for QoS multicast routing based on an extension of the MAODV routing protocol that deals with delay, bandwidth and packet loss mesurements. The solution is based on lower layer specifics. Simulation results show that, with the proposed QoS multicast routing protocol, end-to-end delay, bandwidth and packet loss on a route can be improved in most of cases. It is an available approach to multicast routing decision with multiple QoS constraints.

关键词： multieast routing routing protocol QoS AODV MAODV.

Distributed QoS multicast routing protocol in ad hoc networks

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Journal of Systems Engineering and Electronics 2006年第3期17卷 692-698页

作者： Sun Baolin Li Layuan School of Computer science and Technology Wuhan Univ. of Technology Wuhan 430063 P. R. China Dept. of Mathematics and Physics Wuhan Univ. of Science and Engineering Wuhan 430073 P. R. China

Quality of service （QoS） routing and multicasting protocols in ad hoc networks are face with the challenge of delivering data to destinations through multihop routes in the presence of node movements and topology changes. The multicast routing problem with multiple QoS constraints is discussed, which may deal with the delay, bandwidth and cost metrics, and describes a network model for researching the ad hoc networks QoS multicast routing problem. It presents a distributed QoS multicast routing protocol （DQMRP）. The proof of correctness and complenty analysis of the DQMRP are also given. Simulation results show that the multicast tree optimized by DQMRP is better than other protocols and is fitter for the network situations with frequently changed status and the realtime multimedia application. It is an available approach to multicast routing decision with multiple QoS constraints.

关键词： ad hoc network multicast routing routing protocol QoS.

Fuzzy-Immune PID Control for AMB Systems

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Wuhan University Journal of natural sciences 2006年第3期11卷 637-641页

作者： SU Yixin LI Xuan ZHOU Zude CHEN Youping ZHANG Danhong School of Mechanical science and Engineering Huazhong University of Science and Technology Wuhan 430074 Hubei China School of Automation Wuhan University of Technology Wuhan 430070 Hubei China

In order to improve the dynamic performance of active magnetic hearing systems with highly nonlinear and naturally unstable dynamics, a new nonlinear fuzzy-immune proportional integral-derivative （PID） controller is proposed by combining the immune feedback law with linear PID con trol. This controller consists of a PID controller and a basic immune proportional controller in cascaded connection, the nonlinear function of the immune proportional controller is realized by using fuzzy reasoning. Simulation results demon strate that the active magnetic bearing system with the proposed controller has better dynamic performance and disturbance rejection ability than using the linear PID controller.

关键词： active magnetic bearings fuzzy reasoning artificial immune fuzzy-immune PID

Human Soluble TRAIL Protein Inducing Apoptosis in Osteosarcoma Cell

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Wuhan University Journal of natural sciences 2007年第6期12卷 1148-1152页

作者： ZHU Shaobo YU Aixi ZHANG Zhongning WU Gang Zhongnan Hospital Wuhan University Wuhan 430071Hubei China

This study is to examine the effect of human recombinant soluble TRAIL （TNF-related apoptosis-inducing ligand） protein inducing apoptosis in MG-63 human osteosarcoma cells. The inhibitive rates of TRAIL to MG-63 cells were detected by MTT assay. The apoptosis induced by TRAIL in MG-63 human osteosarcoma cells was analyzed with FACS and TUNEL and the apoptotic bodies were observed by transmission electron microscope. MTT assay showed that the inhibitive rates of 500, 1 000, 2 000 and 4 000 ng/mL TRAIL for 24 h were 10.1%, 24.3%, 50.6% and 97.7% respectively. Flow cytometric analysis showed that after MG-63 cells were treated with 2 gg/mL TRAIL for 6 h, obvious apoptotic peak would immediately appear before diploid peak. Human soluble TRAIL protein can quickly kill MG-63 osteosarcoma cells selectively, and may have potential value for clinical treatment of osteosarcoma.

关键词： TRAIL (TNF-related apoptosis-inducing ligand) osteosarcoma cell line apoptosis

A Routing Algorithm for Risk-Scanning Agents Using Ant Colony Algorithm in P2P Network

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Wuhan University Journal of natural sciences 2006年第5期11卷 1097-1103页

作者： TANG Zhuo LU Zhengding LI Ruixuan College of Computer science and Technology HuazhongUniversity of Science and Technology Wuhan 430074H ubei China

This paper describes a routing algorithm for risk scanning agents using ant colony algorithm in P2P（peerto peer） network. Every peer in the P2P network is capable of updating its routing table in a real-time way, which enables agents to dynamically and automatically select, according to current traffic condition of the network, the global optimal traversal path. An adjusting mechanism is given to adjust the routing table when peers join or leave. By means of exchanging pheromone intensity of part of paths, the algorithm provides agents with more choices as to which one to move and avoids prematurely reaching local optimal path. And parameters of the algorithm are determined by lots of simulation testing. And we also compare with other routing algorithms in unstructured P2P network in the end.

关键词： risk ant colony algorithm P2P

A Formal Model for BPEL4WS Description of Web Service Composition

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Wuhan University Journal of natural sciences 2006年第5期11卷 1311-1319页

作者： GU Xiwu LU Zhengding College of Computer science and Technology HuazhongUniversity of Science and Technology Wuhan 430074Hubei China

Communicating Sequential Processes （CSP） is a kind of process algebra, which is suitable for modeling and verifying Web service composition. This paper describes how to model Web service composition with CSP. A set of rules for translating composition constructor of Business Process Execution Language for Web Services （BPEL4WS） to CSP notations is defined. According to the rules that have been defined, the corresponding translation algorithm is designed and illustrated with examples . The methods for model checking, model verification and model simulation are also introduced.

关键词： communicating sequential processes Web service Web service composition business process execution language for Web services