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THE MULTIPLICATIVE COMPLEXITY AND ALGORITHM OF THE GENERALIZED DISCRETE FOURIER TRANSFORM(GFT)

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Journal of Computational Mathematics 1995年第4期13卷 351-356页

作者： Y.H. Zeng(7th Department, national university of defence technology, Changsha, China) 国防科技大学七系湖南长沙

In this paper, we have proved that the lower bound of the number of real multiplications for computing a length 2(t) real GFT(a,b) (a = +/-1/2, b = 0 or b = +/-1/2, a = 0) is 2(t+1) - 2t - 2 and that for computing a length 2t real GFT(a,b)(a = +/-1/2, b = +/-1/2) is 2(t+1) - 2. Practical algorithms which meet the lower bounds of multiplications are given.

关键词： DCT II THE MULTIPLICATIVE COMPLEXITY AND ALGORITHM OF THE GENERALIZED DISCRETE FOURIER TRANSFORM Math GFT

Effective Neural Algorithms for Combinatorial Optimization

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Systems Science and Systems Engineering 1993年第4期3卷 326-333页

作者： ZENG Anjun SHA Jichang national university of defence and technology, Changsha 410073, China

This paper provides an overview on the current status of the researches in the field of neural algorithms for combinatorial optimization and makes some comments on the recent development. Meanwhile,we point out that such optimization networks suffer from some serious problems. At the end of this paper, we present the readers some aspects which need more researches in the future.

关键词： neural networks combinatorial optimization NP-complete.

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用运载器评价发动机方案的方法

推进技术 1992年第3期13卷 20-27页

作者：陈杰国防科学技术大学

早期在对液体推进剂火箭发动机方案进行评价与选择时,仅以发动机本身的指标(如比冲、推重比等)作为方案比较的标准。这样没有考虑发动机子系统与运载器总系统的相互联系,得不到合理的评价结果。液体推进剂火箭发动机是航天运载器的一个... 详细信息

早期在对液体推进剂火箭发动机方案进行评价与选择时,仅以发动机本身的指标(如比冲、推重比等)作为方案比较的标准。这样没有考虑发动机子系统与运载器总系统的相互联系,得不到合理的评价结果。液体推进剂火箭发动机是航天运载器的一个子系统,采用运载器的性能指标评价发动机方案才能得到比较客观的结果。本文推导了运载器的评价指标,给出了运载器的线性化质量方程,阐述了运载器设计参数的简化确定方法,由此提出了一个采用运载器评价发动机方案的方法。最后应用提出的方法对五个发动机方案进行了评价。

关键词：液体推进剂火箭发动机方案论证

Essential Extensions,Excellent Extensions and Finitely Presented Dimension

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Acta Mathematica Sinica,English Series 1997年第2期13卷 231-238页

作者： Feng Lianggui (Department of System and Engineering Mathematics,national university of defence technology,Changsha 410073,China) 国防科技大学系统工程系湖南长沙

In Section 1 of this paper,we investigate the finitely presented dimension of an essential extension for a module,and obtain results concerning an essential extension of a torsion-free module. We partially answer the question:When is an essential extension of a finitely presented module(an almost finitely presented module)also finitely presented(almost finitely presented)?In Section 2,we study the C-excellent extensions and the finitely presented *** obtain some results on the homological dimensions of matrix rings and group rings.

关键词： Essential extension Excellent extension Finitely presented dimension

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不等熵一维定常管流数值解法

推进技术 1991年第4期12卷 10-15页

作者：方丁酉国防科学技术大学

不等熵一维定常管流控制方程的数值解法,已有许多讨论,但大多局限于某些特定情况,特别是控制方程在奇点(M=1)附近的计算,还没有一个简便的方法.本文引进新变量,把方程变为非奇异的,提出了对各种不等熵流都适用的数值解法.由于引进了喉... 详细信息

不等熵一维定常管流控制方程的数值解法,已有许多讨论,但大多局限于某些特定情况,特别是控制方程在奇点(M=1)附近的计算,还没有一个简便的方法.本文引进新变量,把方程变为非奇异的,提出了对各种不等熵流都适用的数值解法.由于引进了喉部条件,保证了数值解的唯一性.经过对模型方程的计算精度分析,证明该数值解除了在奇点附近稍有误差外,其它地方与精确解一致.本文最后给出了该方法在无喷管发动机内弹道计算中的应用.

关键词：非平衡流动二相流动数值解火箭发动机

The Second Law of Thermodynamics in a Quantum Heat Engine Model

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Communications in Theoretical Physics 2006年第3期45卷 417-420页

作者： ZHANG Ting CAI Li-Feng CHEN Ping-Xing LI Cheng-Zu Department of Applied Physics,national university of defence technology,Changsha 410073,ChinaCHEN Ping-Xing Key Laboratory of Quantum Information,university of Science and technology of China,Hefei 230026,China Department of Applied Physics National University of Defence Technology Changsha 410073 China Key Laboratory of Quantum Information University of Science and Technology of China Hefei 230026 China

The second law of thermodynamics has been proven by many facts in classical *** there any newproperty of it in quantum world?In this paper,we calculate the change of entropy in ***’s model for quantumheat engine(QHE)and prove the broad validity of the second law of *** is shown that the entropy ofthe quantum heat engine neither decreases in a whole cycle,nor decreases in either stage of the *** second lawof thermodynamics still holds in this QHE ***,although the modified quantum heat engine is capable ofextracting more work,its efficiency does not improve at *** is neither beyond the efficiency of ***’s initialmodel,nor greater than the reversible Carnot efficiency.

关键词： second law of thermodynamics entropy quantum heat engine

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斜切反喷管性能计算

推进技术 1991年第5期12卷 1-6页

作者：方丁酉国防科学技术大学

本文提出了斜切反喷管流场计算方法,内部点用MacCormack二步显格式数值解控制方程,入口边界和固壁边界的参数用物理边界条件和可应用的沿双特征线的相容性方程计算.固壁边界计算中采用了激波装配技术和开关格式,有效地捕获了流场内的激... 详细信息

本文提出了斜切反喷管流场计算方法,内部点用MacCormack二步显格式数值解控制方程,入口边界和固壁边界的参数用物理边界条件和可应用的沿双特征线的相容性方程计算.固壁边界计算中采用了激波装配技术和开关格式,有效地捕获了流场内的激波系列,计算中得到的激波情况和物理分析一致.本文在流场计算的基础上,进行了反喷管的性能计算.本文提出的方法可应用于反喷管的性能预估.

关键词：喷管推力反向气流计算方法火箭发动机

Locally Optimum Detection of Weak Pulse Signals in Non-Gaussian Noise

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Journal of Systems Engineering and Electronics 1991年第1期2卷 74-80页

作者： Liang Min and Sun ZhongkangDept. of Electronic Eng., national university of defence technology, Changsha 410073, Hunan, China Dept. of Electronie Eng. National University of Defence Technology Changsha 410073 Hunan China

In this paper, the problem of locally optimum detection of weak pulse signals in narrow-band non-Gaussian noise is discussed. A generalized model is proposed for locally optimum detectors (LOD) and the corresponding physical meaning is explained. On the basis of this generalized model, the LOD structures are derived for detecting both coherent- and incoherent-pulse signals in narrow-band non-Gaussian noise. The asymptotic relative efficiency (ARE) due to Pitman is used to evaluate the performance of these LODs. Finally, numerical calculations are carried out for the AREs of these LODs and some valuable results are obtained.

关键词： Asymptotic relatie efficiency Locally optimum detector Pulse signal.

A MACHINE OPERATOR OR A DYNAMIC STIMULATOR:—MAKE YOUR VIDEO CLASS INTERACTIVE

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Chinese Journal of Applied Linguistics 1999年第2期22卷 30-33页

作者： Tian Juan national university of defence and technology Changsha,Hunan

An analysis of the different types of interaction taking place during a video-class shows thatcommunicative methods stimulate the students’ language *** video becomes a useful languagelearning tool.

关键词： A MACHINE OPERATOR OR A DYNAMIC STIMULATOR MAKE YOUR VIDEO CLASS INTERACTIVE