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基于MATLAB/PDEtool的轴对称场分析

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铁道学报 2005年第1期27卷 124-127页

作者：张友鹏田铭兴兰州交通大学信息与电气工程学院甘肃兰州730070

MATLAB/PDEtool是非常优秀的二维偏微分有限元求解软件,具有像静电场、静磁场和工频交流电磁场等专业模式,但这些专业模式不能直接用于柱坐标系表示的轴对称场的求解分析。文章推导出了正交坐标系中的泊松方程,并通过柱坐标系中轴对称... 详细信息

MATLAB/PDEtool是非常优秀的二维偏微分有限元求解软件,具有像静电场、静磁场和工频交流电磁场等专业模式,但这些专业模式不能直接用于柱坐标系表示的轴对称场的求解分析。文章推导出了正交坐标系中的泊松方程,并通过柱坐标系中轴对称场的方程形式和直角坐标系中标准二维椭圆型偏微分方程形式的比较,得到了他们坐标之间、系数之间的对应关系,据此用MATLAB/PDEtool对轴对称场进行了求解分析,结果说明本文的方法是有效的。

关键词：平行平面场轴对称场静磁场 MATALAB

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基于谱相减改进算法的语音增强研究

铁道学报 2004年第1期26卷 64-67页

作者：徐岩杨静王维汉兰州交通大学信息与电气工程学院甘肃兰州730070

根据传统的谱相减增强型算法 ,提出了抑制噪声的谱减改进算法 ,暨根据带噪语音帧频谱功率与噪声帧频谱功率比值 ,动态调整α、β谱减系数 ,使之谱减效果在较大提高信噪比的同时 ,又能将残留的音乐噪声和语音失真保持在人耳听觉的容忍范... 详细信息

根据传统的谱相减增强型算法 ,提出了抑制噪声的谱减改进算法 ,暨根据带噪语音帧频谱功率与噪声帧频谱功率比值 ,动态调整α、β谱减系数 ,使之谱减效果在较大提高信噪比的同时 ,又能将残留的音乐噪声和语音失真保持在人耳听觉的容忍范围之内 ,保证原始语音信号质量达到一定的可懂度和清晰度。借助MATLAB语言进行试验仿真 ,仿真结果与原算法相比较。

关键词：语音增强谱相减算法噪声抑制

Discuss on network course construction of electrical engineering experiment

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Discuss on network course construction of electrical enginee...

第三届教学管理与课程建设学术会议

作者： Yufang Gong, Xinying LI Electronics&information engineering college,lanzhou jiaotong university,lanzhou,china,730070

The electrical engineering experimental course is one of specialized technology compulsory course of non-electrical undergraduate majors of engineering colleges. One of the main features of this course is that face specialty widely, the number of students is large, combined with the features of the course and present problems, in order to cultivate creative talents as the goal, it reform and explore the teaching methods and means of electrical engineering experiment. Designing the network teaching platform of electrical engineering experiment, the platform increase the flexibility of teaching greatly ,at the same time improve the quality of teaching effectively.

关键词： electrical engineering experiment teaching reformation Network course

Approximately optimal tracking control for discrete time-delay systems with disturbances

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Progress in Natural Science:Materials International 2008年第2期18卷 225-231页

作者： Gongyou Tang a,,Huiying Sun b,Haiping Pang c a college of information Science and engineering,Ocean university of china,Qingdao 266100,china b college of information and electrical engineering,Shandong university of Science and Technology,Qingdao 266510,china c college of Automation and Electronic engineering,Qingdao university of Science and Technology,Qingdao 266042,china college of information Science and engineering Ocean University of China Qingdao 266100 China college of information and electrical engineering Shandong University of Science and Technology Qingdao 266510 China college of Automation and Electronic engineering Qingdao University of Science and Technology Qingdao 266042 China

Optimal tracking control (OTC) for discrete time-delay systems affected by persistent disturbances with quadratic performance index is considered. By introducing a sensitivity parameter,the original OTC problem is transformed into a series of two-point boundary value (TPBV) problems without time-advance or time-delay terms. The obtained OTC law consists of analytic feedforward and feedback terms and a compensation term which is the sum of an infinite series of adjoint vectors. The analytic feedforward and feedback terms can be found by solving a Riccati matrix equation and two Stein matrix equations. The compensation term can be obtained by using an iteration formula of the adjoint vectors. Observers are constructed to make the approximate OTC law physically realizable. A simulation example shows that the approximate approach is effective in tracking the reference input and robust with respect to exogenous persistent disturbances.

关键词： Discrete systems Time-delay systems Disturbances Optimal control Tracking control

Improving TCP Performance over Wireless Links Using Link-Layer Retransmission and Explicit Loss Notification

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Journal of Systems engineering and Electronics 2002年第4期13卷 17-23页

作者： Zhou Zhizhao & Han Zhengzhi college of Electronic and information engineering, Shanghai jiaotong university, Shanghai 200030, P. R. china college of Electronic and information engineering Shanghai Jiaotong University Shanghai 200030 P. R. China

In order to support the mobility of computers during communication, the transport control protocol (TCP) connections between fixed host and mobile host often traverse wired and wireless networks, and the recovery of the losses due to wireless transmission error is much different from congestion control. This paper analyzes the interaction between TCP and link layer retransmission scheme when the correlated packet are losses handled, indicates that a higher value of the maximum number of successive link layer timeout retransmissions has an adverse effect on TCP ability to perform congestion control rapidly. To achieve a better TCP performance, the paper proposes a strategy combining link-layer selective-reject automatic repeat request (ARQ) with explicit loss notification mechanism, which can respond to congestion quickly while keeping wireless link more reliable, and make TCP react to the different packet losses more suitably.

关键词： Congestion control (communication) Mechanisms Performance Transmissions

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曲柄滑块机构中滑块输出位移的可靠性分析

上海交通大学学报 2010年第12期44卷 1716-1720,1726页

作者：同长虹黄建龙兰州理工大学机电工程学院兰州730070 兰州城市学院机械监测与故障诊断研究所兰州730070

建立了运动副磨损量的计算模型.通过机构的运动学和动力学分析计算运动副元素之间的接触力和相对运动速度,在运动副连续接触理论和各随机因素符合正态分布的假设下,建立了曲柄滑块机构滑块输出位移可靠度模型,利用编写的Matlab计算程序... 详细信息

建立了运动副磨损量的计算模型.通过机构的运动学和动力学分析计算运动副元素之间的接触力和相对运动速度,在运动副连续接触理论和各随机因素符合正态分布的假设下,建立了曲柄滑块机构滑块输出位移可靠度模型,利用编写的Matlab计算程序对所建立的模型进行了实例计算,得出了机构随着工作时间的延长运动副元素的磨损影响越突出的结论.所建的模型可以估算机构工作一定时间后的运动精度可靠度,也可以推算在给定要求下机构的工作寿命.

关键词：曲柄滑块机构运动副磨损原始误差位移可靠性

On The Adjacent Vertex-Distinguishing Edge Coloring of Km·Cn*

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On The Adjacent Vertex-Distinguishing Edge Coloring of Km·C...

中国运筹学会第七届学术交流会

作者： Ma Shengquan Li Jingwen Zhang Zhongfu Department of Mathematic, Northwest Minorities university,lanzhou 730030,P.R.china college of Mathematics and information Science, Northwest Normal university, lanzhou 730070,P.R.china Department of computer, lanzhou Normal college, lanzhou 730070, P.R.china Institute of Applied Mathematic,lanzhou jiaotong university, lanzhou 730070, P.R.china college of information and electrical engineering, lanzhou jiaotong university, lanzhou Gansu,730070, P.R. china

K·C is called a join Graph, if V(K·C) ={v|i=1, 2,…,m;j=1, 2,…, n}, E(K·C) ={vv, vv,…,vi(n-1))v, vv|i=1, 2,…,m}∪{vv(i+l)1)|i = 1, 2,…, m - 1}. In this paper, we obtained the adjacent vertex-distinguishing edge... 详细信息

关键词： Graph adjacent vertex-distinguishing edge coloring adjacent vertex-distinguishing edge chromatic number

On The Adjacent Vertex-Distinguishing Edge Coloring of Km·Sn1

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On The Adjacent Vertex-Distinguishing Edge Coloring of Km·S...

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作者： Ma Ming Li Jingwen Liu Hua Department of Mathematic,Northwest Minorities university,lanzhou 730030,P.R.china college of information and electrical engineering, lanzhou jiaotong university lanzhou Gansu,730070,P.R.china

Suppose V(K·S) ={u|i = 1,2,…,m} ∪{v|i = 1,2,…,m;j =1, 2,…, n}, E(K·S) = {uu|i = 1, 2,…, m-1;j = i+1, i+2,…, m}∪{uv|i =1, 2,…, m;j = 1, 2,…, n}. In this paper, we obtained that the adjacent vertex-distinguis... 详细信息

关键词： Graph adjacent vertex-distinguishing edge coloring adjacent vertex-distinguishing edge chromatic number

On The Edge Coloring And The Adjacent Vertex-Distinguishing Edge Coloring of Km·Wn1

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On The Edge Coloring And The Adjacent Vertex-Distinguishing ...

中国运筹学会第七届学术交流会

作者： Ma Shengquan Li Jingwen Ma Shaoxian Zhang Zhongfu Department of Mathematic,Northwest Minorities university,lanzhou 730030,P.R.china college of information and electrical engineering,lanzhou jiaotong university, lanzhou Gansu,730070, P.R. china college of Mathematics and information Science, Northwest Normal university, lanzhou 730070,P.R.china Department of computer, lanzhou Normal college, lanzhou 730070, P.R.china Institute of Applied Mathematic, lanzhou jiaotong university,lanzhou 730070, P.R.china

(K·W) = {u|i = 1, 2,…, m}∪{v|i = 1,2,…,m;j = 1, 2,…,n},E(K·W) = {uu|i = 1,2,…, m - 1;j = i + 1,i + 2,…,m}∪{uv|i =1,2,…,m;j = 1,2,…,n}∪{vv(j+1)|i = 1,2,…,m;j = 1,2,…,n - 1}∪{vv|i = 1, 2,…,m}. In this pa... 详细信息

关键词： Graph edge color edge chromatic number adjacent vertex-distinguishing edge coloring adjacent vertex-distinguishing edge chromatic number