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111.
112.
本文利用模糊集理论,提出一种非确定环境的描述方法,并且针对机器人在该类环境中的避障轨迹规划,建立了相应的决策函数和规划策略,最后,给出在PC-386计算机上的仿真试验结果。 相似文献
113.
用保形样条方法求解非定常对流扩散方程 总被引:1,自引:0,他引:1
在欧拉-拉格朗日分裂方法的基础上,本文发展了一种固定网格上的欧拉-拉格朗日分裂方法.保形样条方法(SPSM)被用来解决倒特征线插值问题.通过求解几个有精确解的例子,说明SPSM方法的解是单调无振荡的,并且数值耗散也是比较小的. 相似文献
114.
We derive a general equation relating probability densities and as special cases we the obtain Gram-Charlier and Edgeworth series. This allows us to generalize these methods and clarify a number of issues pertaining to both probability theory and time-frequency analysis. In particular we show how the Gram-Charlier and Edgeworth series are related to the kernel method of time-frequency analysis. The approach allows us to construct densities that satisfy given constraints such as joint moments or conditional moments. Also, we show that the kernel has to be signal dependent and that to obtain a proper distribution it should be the ratio of two characteristic functions. 相似文献
115.
New technologies such as power electronics have made it possible to change continuously the impedance of a power system not only to control power flow but also to enhance stability. A power system incorporating a variable impedance apparatus such as a variable series capacitor (VSrC) and high-speed phase shifter (HSPS) is called VIPS (Variable Impedance Power System) by the authors. This paper proposes a novel control method of VIPS apparatus such as VSrC and HSPS installed at an interconnecting point for stabilizing inter-area unstable and/or oscillatory modes. The proposed design method of the control system is a kind of hierarchical decentralized control method of a large-scale power system based on a Lyapunov function. Under the proposed control scheme, each subsystem can be stabilized independently by local controllers such as AVR, speed governor and PSS, and then the whole interconnected system can be stabilized by VIPS apparatus taking into account interactions between subsystems. The effectiveness and robustness of the VIPS apparatus control are shown by numerical examples with model systems including a large-scale power system. 相似文献
116.
用平衡法核素心室造影自动左心室功能测定法检查了23例正常人、37例无心肌梗塞(CAD-NMI)和14例有心肌梗塞(CAD-MI)冠心病人左心室功能。结果表明,PFR反映心肌缺血改变比其他心功能参数敏感。CAD-NMI组与正常对照组比较,PFR的灵敏度为94.59%,P〈0.001,其他参数的灵敏度依次为TPFR54.05%,P〈0.01;PER54.05,P〈0.01;TPER49.95%,P〈0 相似文献
117.
采用X射线衍射分析技术,研究了脉冲化学镀非晶态Ni-P合金的原子分布和函数,得出其短程有序原子集团的尺度为0.754nm,约为熔体激冷法获得的非晶态Ni-P合金短程有序畴的1/2。并利用脉冲化学沉积非晶态合金的微机制择这一结果进行了解释。 相似文献
118.
This paper considers the equalisation problem in Quadrature Phase-Shift Keying (QPSK) modulated signals which have been distorted by the passage through a transmission channel. The channel is modelled as a Rician fading channel to simulate the behaviour of the transmission channel in the mobile satellite context. The equalisation is treated as the generalisation of the channel behaviour, and some algorithms with the structure of an artificial neural network using the Multilayer Perceptron, Volterra Series and Radial Basis Function are described. Results for the BER performance of typical transversal equalisers, with Square-Root Kalman adaptation algorithm, and algorithms with artificial neural network structure are also reported and evaluated. Improved performance is exhibited by the artificial neural network approaches. 相似文献
119.
120.
R. Hughes 《Information Systems Journal》1994,4(3):169-183
Abstract. This paper examines critically the function point analysis mark II (FPA mark II) method of measuring the functionality of information systems. Although the focus of the paper is on FPA mark II as devised by Symons, both this and the Albrecht method, from which the FPA mark II was developed, are briefly discussed. The published attempts to validate FPA mark II are reviewed and then the problems encountered by the author in applying the approach are described. The final part of the paper is concerned with the fit between SSADM and FPA mark II. 相似文献