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Performance Analysis of TCP-Reno and TCP-Sack in the Case of a Single Source

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Wuhan University Journal of Natural Sciences 2000年第1期5卷 70-74页

作者： Wang, xin-miao Yan, Pu-liu huang, tian-xi Wuhan Univ Wuhan China

This work explores the behavior of both TCP-Reno and TCP-Sack under a simple scenario, where a single TCP source transmits the packets continuously over a single bottleneck node characterized by its queue size, bandwidth and propagation delay. The analysis allows to derive the performance of TCP, the utilization tends to 75% of the bottleneck throughput when the bandwidth×propagation delay pipe becomes very large, while it tends to 100% when the queuing delays are predominant because the queue is never empty. In the transient analysis we show how the initial phase of the session can degrade the performances. These results are proved through simulation.

关键词： Bandwidth Congestion control (communication) Packet networks Telecommunication traffic

A Design of the Elliptic Switched Current Filter

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Wuhan University Journal of Natural Sciences 1999年第2期4卷 39-43页

作者： Zhu Da-bin huang tian-xi Yao Yong-gang Su Yu-bei Wuyi University Department of Electronic and Information Engineering Jiangmeng China (GRID:grid.443414.2) (ISNI:***) Wuhan University College of Electronic Information Wuhan China (GRID:grid.49470.3e) (ISNI:***) Wuhan University College of Electronic Information Wuhan China (GRID:grid.49470.3e) (ISNI:***)

In conformity with a fifth order RLC elliptic filter circuit prototype, it is easy to conceive the corresponding RC active filter circuit. Simple and feasible method presented here can be used to contrive the equivalent switched capacitor filter circuit and switched current filter circuit. Consulting the technique data manual, we can expediently design a specific RLC filter. Therefore, it is of great convenience to design the switched current filter, which has the same performances. Such a kind of technology is useful in the domain of analogue sampled data signal processing.

关键词： switched current switched capacitor active RC elliptic filter

Construction of Network Fault Simulation Platform and Event Samples Acquisition Techniques for Event Correlation

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Wuhan University Journal of Natural Sciences 2001年第3期6卷 670-674页

作者： Su Yu-bei Wang Zhi Cao Yang huang tian-xi Wang Li-na College of Electronic Information Wuhan University Wuhan 430072 China

Event correlation is one key technique in network fault management. For the event sample acquisition problem in event correlation, a novel approach is proposed to collect the samples by constructing network simulation platform. The platform designed can set kinds of network faults according to user's demand and generate a lot of network fault events, which will benefit the research on efficient event correlation techniques.

关键词： event correlation network fault simulation event sample

Knowledge Discovery from Communication Network Alarm Databases

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Wuhan University Journal of Natural Sciences 2000年第2期5卷 194-198页

作者： Wang xin-miao huang tian-xi Yan Pu-liu Chong Yan-wen Wuhan University College of Electronic Information Wuhan China (GRID:grid.49470.3e) (ISNI:***)

The technique of Knowlege Discovery in Databases (KDD) to learn valuable knowledge hidden in network alarm databases is introduced. To get such knowledge, we propose an efficient method based on sliding windows (named as Slidwin) to discover different episode rules from time squential alarm data. The experimental results show that given different thresholds parameters, large amount of different rules could be discovered quickly.

关键词： KDD alarm databases sliding window algorithm episode rules

A Study on Ionospheric HF Channel with Bitemporal Response and Scattering Function

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Wuhan University Journal of Natural Sciences 2000年第3期5卷 317-319页

作者： Chong Yan-wen xie Shu-guo Zhao Zheng-yu huang tian-xi Yao Yong-gang Wuhan University College of Electronic Information Wuhan China (GRID:grid.49470.3e) (ISNI:***)

At first the bitemporal response method is introduced to solve the scattering function of the ionospeeric channel. We can get the scattering function, as a function, of the group path time delay and Doppler frequency. Thus Doppler effect resulting from the continuous movement of the ionosphere is analyzed to study the characteristics of the various ionospheric irregularities and diturbance. many possible problems and correction are researched lastly.

关键词： bitemporal response function scattering function the Doppler effect the movement of the ionosphere

Performance Analysis of Parallel Interference Cancella tion for Multi-carrier DS-CDMA

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Semiconductor Photonics and Technology 2005年第3期11卷 154-160页

作者： XU Guo-xiong GAN Liang-cai huang tian-xi School of Electron. Inform. Zhongyuan University of Technology Zhengzhou 450007 CHN School of Electron. Inform. Wuhan University Wuhan 430079 CHN

The parallel interference c an cellation for multi-carrier DS-CDMA (which is termed FDC-PIC) is proposed by integrating frequency diversity combination. The simulations are made over FDC- PIC with respect to different decision ways——hard, soft and linear decisions, respectively, and we conclude that FDC-PIC acquires superior performance improv ement over correlation reception of multi-carrier DS CDMA. With an increase in interference cancellation stages, the system performance is improved further. Th e initial 2 stages bring about the most dominant performance improvement, but up to the 3rd stage the system performance is improved little. It is also shown by the simulation results that FDC-PIC with soft decision would exhibit the best performance with a high implementation complexity, while FDC-PIC with linear de cision acquires performance comparable to that of FDC-PIC with soft decision wi th a reduced-complexity if the number of the interference cancellation stages i s the same, which indicates that FDC-PIC with linear decision has optimal perfo rmance/complexity tradeoff and therefore will be suitable for practical applica tion in future.

关键词： Multi-carrier DS-CDMA Parallel interference cancellation

Two Methods to Solve the Ionospheric Electron Concentration Horizontal Gradient at Chongqing

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Wuhan University Journal of Natural Sciences 2000年第3期5卷 320-322页

作者： Chong Yan-wen, huang tian-xi, Zhao Zheng-yu, xie Shu-guo, Yao Yong-gang College of Electronic Information, Wuhan University, Wuhan 430072, China Wuhan University College of Electronic Information Wuhan China (GRID:grid.49470.3e) (ISNI:***)

The electron concentration horizontal gradient vector of the ionosphere and its south-north and east-west components over Chongqing station are analyzed and calculated, using the first approximation, time correlation and space correlation and another approach introduced. And then, the validity of the two methods is analyzed and compared.

关键词： horizontal gradient of ionospheric electron concentration horizontal gradient vector space correlation time correlation

基因芯片技术对乙型肝炎病毒拉米夫定耐药基因变异检测的临床应用

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中华实验和临床病毒学杂志 2007年第2期21卷 185-187页

作者：黄希田曾爱平林峰温州医学院附属温岭医院 317500

目的通过对应用拉米夫定治疗患者HBV基因耐药性变异的长期监测，验证基因芯片技术的临床应用前景。方法针对HBV3个主要的拉米夫定耐药性相关突变设计探针，制成HBV耐药寡核苷酸芯片，选取51例应用拉米夫定进行治疗的乙型肝炎患者分别采... 详细信息

目的通过对应用拉米夫定治疗患者HBV基因耐药性变异的长期监测，验证基因芯片技术的临床应用前景。方法针对HBV3个主要的拉米夫定耐药性相关突变设计探针，制成HBV耐药寡核苷酸芯片，选取51例应用拉米夫定进行治疗的乙型肝炎患者分别采用基因芯片和传统测序的方法对其进行24个月的监测，观察HBV基因变异情况。结果39％的患者在用药2年内发生了耐药性突变，使用基因芯片与传统的测序方法得到的结果一致，并且可以在早期方便检测出混合感染。结论应用基因芯片技术可以准确，高效的检测出耐药基因变异，具有临床应用价值。

关键词：药物耐受,病毒突变肝炎病毒,乙型拉米夫定单核苷酸序列分析

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大型螺旋锥齿轮的齿距测量

机械设计与制造 2008年第11期 208-209页

作者：颜祯黄天喜中南大学机电工程学院长沙410075

在比较了两种齿距测量的仪器后,最终采用跨齿相对法作为齿距累积误差在机测量方案、无线电传输式测头系统作为测量的测头系统,并给出了计算过程和计算公式。

关键词：大型螺旋锥齿轮齿距测量测头系统