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Adaptive Synchronization in Small-World Dynamical Networks

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Journal of Shanghai Jiaotong university(Science) 2007年第2期12卷 211-215页

作者：邹艳丽朱杰罗晓曙 Dept.of electronic eng. Shanghai Jiaotong Univ. Dept.of Physics and electronic eng. Guangxi Normal Univ.

Adaptive synchronization in NW small-world dynamical networks was studied. Firstly, an adaptive synchronization method is presented and explained. Then, it is applied to two different classes of dynamical networks, one is a class-B network, small-world connected R6 ssler oscillators, the other is a class-A network, small-world connected Chua＇s circuits. The simulation verifies the validity of the presented method. It also shows that the adaptive synchronization method is robust to the variations of the node systems parameters. So the presented method can be used in networks whose node systems have unknown or time-varying parameters.

关键词： NW small-world network master stability function adaptive synchronization

A New Arithmetic Coding System Combining Source Channel Coding and MAP Decoding

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Journal of Shanghai Jiaotong university(Science) 2007年第4期12卷 442-447页

作者：逄玉叶孙军王嘉 Dept.of electronic eng. Shanghai Jiaotong Univ.

A new arithmetic coding system combining source channel coding and maximum a posteriori decoding were proposed. It combines source coding and error correction tasks into one unified process by introducing an adaptive forbidden symbol. The proposed system achieves fixed leng.h code words by adaptively adjusting the probability of the forbidden symbol and adding tail digits of variable leng.h. The corresponding improved MAP decoding metric was derived. The proposed system can improve the performance. Simulations were performed on AWGN channels with various noise levels by using both hard and soft decision with BPSK *** results show its performance is slightly better than that of our adaptive arithmetic error correcting coding system using a forbidden symbol.

关键词： arithmetic code (AC) forbidden symbol joint source channel coding (JSCC) maximum a posteriori (MAP) decoding

Wavelet De-noising of Speech Using Singular Spectrum Analysis for Decomposition Level Selection

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Journal of Shanghai Jiaotong university(Science) 2007年第2期12卷 190-196页

作者：蔡铁朱杰 Dept.of electronic eng. Shanghai Jiaotong Univ.

The problem of speech enhancement using threshold de-noising in wavelet domain was *** appropriate decomposition level is another key factor pertinent to de-noising *** paper proposed a new wavelet-based de-noising scheme that can improve the enhancement performance significantly in the presence of additive white Gaussian *** proposed algorithm can adaptively select the optimal decomposition level of wavelet transformation according to the characteristics of noisy *** experimental results demonstrate that this proposed algorithm outperforms the classical wavelet-based de-noising method and effectively improves the practicability of this kind of techniques.

关键词： speech enhancement wavelet de-noising singular spectrum analysis (SSA) support vector machine (SVM)

Efficient Accurate Context-Sensitive Anomaly Detection

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Journal of Shanghai Jiaotong university(Science) 2007年第5期12卷 639-644,650页

作者：李红娇李建华 Dept.of electronic eng. Shanghai Jiaotong Univ.

For program behavior-based anomaly detection, the only way to ensure accurate monitoring is to construct an efficient and precise program behavior model. A new program behavior-based anomaly detection model, called combined pushdown automaton (CPDA) model was proposed, which is based on static binary executable analysis. The CPDA model incorporates the optimized call stack walk and code instrumentation technique to gain complete context information. Thereby the proposed method can detect more attacks, while retaining good performance.

关键词： program behavior-based anomaly detection system call combined pushdown automaton (CPDA) model

Performance Analysis of Two Frequency Reuse Schemes in Fixed Relay Systems

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Journal of Shanghai Jiaotong university(Science) 2007年第2期12卷 216-222页

作者：黄磊戎蒙恬 Dept.of electronic eng. Shanghai Jiaotong Univ.

An upsurge of interest in relay-augmented infrastructure-based networks has appeared in recent *** resource management in such relay systems has great influence on the system *** to utilize the limited frequency resources efficiently in the system is a hot research *** this paper,performance of frequency reuse schemes has been studied in fixed relay systems.A novel scheme is achieved by modifying an existing *** model is proposed for the performance analysis of two *** the theoretical analysis and simulation results show that the modified scheme outperforms the existing one not only in power consumption of mobile stations but also in cell carrier-to-interference ratio coverage.

关键词： frequency reuse fixed relay system power consumption carrier-to-interference ratio

A New Traffic Model for Mobile Wireless Networks

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Journal of Shanghai Jiaotong university(Science) 2007年第4期12卷 471-476页

作者：赵方明蒋铃鸽何晨 Dept.of electronic eng. Shanghai Jiaotong Univ.

A new traffic model for mobile wireless networks was given and analysed. In the model, it is considered of traffic characteristic for two special periods of time. A pre-emptive priority scheme combined with channel borrowing strategy according to the speciality was proposed. All the channels can be used by non-real-time services, and real-time services are given higher priority for they are allowed to pre-empt channels used by non-real-time services. Either real-time handoff requests or non-real-time handoff requests can be queued in queues when there is no channel can be used. Some channels are reserved for real-time handoff requests, which can also be used by non-real-time service when they are idle. Simulation results are also given. It is seen that our scheme performs better than other schemes when the arrival rate of real-time services is much higher than non-real-time services.

关键词： wireless network handoff channel allocation transition cell blocking probability

Influence of Error-prone Channel on the Performance of IEEE 802.11 WLAN Utilizing RTS/CTS Handshaking

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Journal of Shanghai Jiaotong university(Science) 2007年第6期12卷 799-804页

作者： Haider M. AlSabbagh 陈建平徐友云 Dept. of electronic eng. Shanghai Jiaotong Univ.

A comprehensive study was presented for WLAN 802.11b using error-prone channel. It was theoretically and numerically evaluated the performance of three different network sizes with the bit rates that available in 802.11b protocol. Results show that throughput does not change with the size of the network for wide range of bit error rates (BERs) and the channel bit rates play a significant role in the main characteristics of the network. A comprehensive explanation has given for the phenomenon of the packet delay suppression at relatively high level of BERs in view of the size of the networks and the BERs. The effect leng.h of the transmitting packets is also investigated.

关键词： IEEE802.11b request to send/clear to send(RTS/CTS) wireless local area network(WLAN) error-prone channel

Efficient Protocol-Proving Algorithm Based on Improved Authentication Tests

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Journal of Shanghai Jiaotong university(Science) 2007年第1期12卷 9-17页

作者：李谢华杨树堂李建华诸鸿文 Dept.of electronic eng. Shanghai Jiaotong Univ.

A new efficient protocol-proving algorithm was proposed for verifying security protocols. This algorithm is based on the improved authentication tests model, which enhances the original model by formalizing the message reply attack. With exact causal dependency relations between messages in this model, the protocol-proving algorithm can avoid the state explosion caused by asynchronous. In order to get the straight proof of security protocols, three authentication theorems are exploited for evaluating the agreement and distinction properties. When the algorithm terminates, it outputs either the proof results or the potential flaws of the security protocol. The experiment shows that the protocol-proving algorithm can detect the type flaw attack on Neuman-Stubblebine protocol, and prove the correctness of NSL protocol by exploring only 10 states.

关键词： protocol-proving algorithm improved authentication tests Neuman-Stubblebine protocol NSL protocol

Increasing Plant Availability by Mechanical Checking of the Cement Rotary Kiln Axis

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Journal of Wuhan University of Technology(Materials Science) 2001年第3期16卷 76-78页

作者：张云 School of Mechanical electronic eng. Wuhan University of Technology Wuhan 430070 China

A periodic check of the cement rotary kiln axis is needed withinthe framework of preventive ma- intenance for maintaining high plantavailability. The fourth generation 'KAS-4' measuring system wasdevel- oped by Wuhan University of Technology in 1999. The system canbe carried out with rotating or stationary kiln plant. The same istrue of the measurement of tire and supporting roller diameters, theclearance of tires, the po- sition of rollers, the machining of tiresand rollers, the slops of roller surfaces, the deflection of gear,the axis of kiln. The system has been applied to the measurement for10 set of cement rotary kiln in China.

关键词： cement kiln axis diameter