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81.
82.
王茹 《系统工程与电子技术》1993,(11)
本文用有限元方法研究有液体流动管道在空间内振动,液体流速与压强对其固有频率的影响。给出运动微分方程及其解法,并通过实例加以验证。 相似文献
83.
LI Jianping TIAN Feng SHEN Ruqun Institute of Systems Science Academia Sinica Beijing China Institute of Biophysics Academia Sinica Beijing China 《系统科学与复杂性》1993,(1)
Let G be a graph of order n. We define the distance between two vertices u andv in G, denoted by d(u, v), as the minimum value of the lengths of all u-v paths. We writeσ_k(G)=min{∑_i=1~k d(v_i)|{v_1, v_2,…, v_k} is an independent set in G} and NC2(G)=min {|N(u)∪N(v)| | d(u, v)=2}. We denote by ω(G) the number of components of agraph G. A graph G is called 1-tough if ω(G\S)≤|S| for every subset S of V(G) withω(G\S)>l. By c(G) we denote the length of the longest cycle in G; in particular, G iscalled a Hamiltonian graph if c(G)=n. H.A. Jung proved that every 1-tough graphwith order n≥11 and σ2≥n-4 is Hamiltonian. We generalize it further as follows: ifG is a 1-tough graph and σ3(G)≥n, then c(G)≥min {n,2NC2(G)+4}. Thus, theconjecture of D. Bauer, G. Fan and H.J. Veldman in [2] is completely solved. 相似文献
84.
Wang FuhengBeijing Institute of Environment Features P.O.Box - Beijing China 《系统工程与电子技术(英文版)》1991,(1)
A systematic elaboration is given on atomic and molecular theory problems encountered in dealing with space science and engineering. Three sections are presented in the paper on calculations for gas thermodynamic and transfer properties, characteristics of the optical radiation from the reentry' bodies, and the interaction between surfaces of man-made satellites and incident particles. Researches on them are much related to the fundamental problems regarding the atomic and molecular theory. 相似文献
85.
Hu Yi He DehuanBeijing Institute of Remote Sensing Equipment P. O. Box Beijing China 《系统工程与电子技术(英文版)》1991,(1)
A new type of vocoder system based upon formant analysis is presented in this paper. The LMS adaptive algorithm is used for tracking formants of speech signals. The results of computer simulation show that the new vocoder has better synthesized speech quality. 相似文献
86.
Qiangfu Zhao Zhong Wang Youan KeDept. of Electronic Eng. Beijing Institute of Technology P.O.Box Beijing China 《系统工程与电子技术(英文版)》1991,(2)
It has long been realized that the problem of radar imaging is a special case of image reconstruction in which the data are incomplete and noisy. In other fields, iterative reconstruction algorithms have been used successfully to improve the image quality. This paper studies the application of iterative algorithms in radar imaging. A discrete model is first derived, and the iterative algorithms are then adapted to radar imaging. Although such algorithms are usually time consuming, this paper shows that, if the algorithms are appropriately simplified, it is possible to realize them even in real time. The efficiency of iterative algorithms is shown through computer simulations. 相似文献
87.
Lu Caicheng & Wang BaofaDept. of Electronic Eng. Beijing University of Aeronautics Astronautics Beijing China 《系统工程与电子技术(英文版)》1991,(2)
A new method of calculating the radai cross section (RCS) for wing-body blended targets is presented and verified. The method utilizes a computer program for modeling targets' geometry in terms of small pieces. The calculation is based on physical optics approximation. Examples are given to show the validity of the method. 相似文献
88.
Song Liuping Sun ZhongkangDept. of Electronic Eng. National Univ. of Defense Technology Changsha China 《系统工程与电子技术(英文版)》1991,(2)
The purpose of this paper is to develop a high speed detection scheme for moving and / or stationary point targets in a multitarget environment as registered in an IR image sequence. An iterative approximate 3-D line searching algorithm based upon the geometric representation of lines (for non-maneuvering targets in space) in a 3-D space is derived. The convergency of the algorithm is proved. An analysis is performed of the theoretical detection performance of the algorithm. The statistical experiment results show high effectiveness and computational efficiency of the algorithm in the case of low SNR. The idea may be employed to satisfy the real-time processing requirement of an IR system. 相似文献
89.
中国航天工程可靠性理论研究成果综述 总被引:5,自引:0,他引:5
何国伟 《系统工程与电子技术》1991,(1)
近年来,九个研究所及大学在航空航天部质量司的“基础可靠性理论研究基金”支持资助下,对若干在航天研制中需要解决的可靠性统计问题进行了研究。本文对主要成果作概括介绍,包括对正态分布的成果;对Weibull分布的成果;系统可靠性综合的成果——理化方法,近似方法、(二项分布,指数分布,Weibull分布,并联系统),一般情况;结构可靠性;零失效可靠性估计;贮存可靠性;其它成果。由“基础可靠性理论研究基金”支持资助的所有研究成果都是非密的,可以从航空航天部质量司得到。 相似文献
90.
本文从工业系统技术进步、工业效率、工业经济效益、工业部门和行业结构以及工业发展速度的稳定性分析等方面对地区工业发展的合理性进行全面的科学考察和综合性定量评估,并设计了相应的综合性定量评价指标体系。该指标体系曾用于南京市工业发展的合理性评价,取得成功并受到专家好评。 相似文献