静电加速器和串列静电加速器金属梯感应输电系统的研制

本文介绍了金属梯感应输电系统的工作原理、主要技术关。并给出了我们的研制情况和实验结果。     

Chaotic Spread- Spectrum Communication using Discrete-Time Synchronization

ＣｈａｏｔｉｃＳｐｒｅａｄＳｐｅｃｔｒｕｍＣｏｍｍｕｎｉｃａｔｉｏｎｕｓｉｎｇＤｉｓｃｒｅｔｅＴｉｍｅＳｙｎｃｈｒｏｎｉｚａｔｉｏｎＷａｎｇＨａｉａｎｄＨｕＪｉａｎｄｏｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＴｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓＥｎｇｉｎｅ...     

Two classes linear discrimination A min-max approach

In this paper we propose a new dichotomic linear discrimination algorithm based on a criterion recursively defined from the min and max functions. This criterion allows us, using a gradient algorithm, to find two hyperplanes which split two classes in an optimal way. We give two examples of the possibilities of the method.     

A 64 kbit/s Videophone codec with forward analysis and control

A new combination of coding methods for a 64 kbit/s transmission system for typical videophone situations is investigated. The codec structure is based on a standard hybrid discrete cosine transform (DCT) codec with temporal prediction. The picture is divided blockwise into changed and unchanged areas. One motion vector with subpel accuracy is computed and transmitted for each block of the changed area. For the forward analysis, the prediction error is calculated in the whole picture. Only the blocks with the highest prediction errors are updated by a DCT with a perception adaptive quantization. The number of DCT update blocks depends on the remaining bits after the transmission of the overhead information. The codec is controlled by a forward analysis of the prediction error and is not based on a buffer control. The spatial resolution of the source signal is reduced in two steps to prevent a codec overload caused by too much activity between two frames.     

线性离散事件动态系统的鲁棒性*

应用极大代数,可对一类离散事件动态系统建立线性模型,本文讨论这类系统的鲁捧性,首先系统地讨论了系统中有一个参数发生摄动时对整个系统动态性能的影响,并对系统参数按照这种影响进行了分类,对于系统中有多个参数同时发生增性摄动的情况,给出了不影响系统动态性能的各个参数的允许摄动范围,亦即鲁棒性条件,这个范围在一定意义下是最大允许的参数摄动范围。     

An edge preserved image compression technique

An image compression technique that can preserve edges of objects is proposed here. This technique is developed by looking at small local regions of the image and classifying these regions as uniform, point, line or edge patterns from statistical likelihood ratio tests. The compression ratio depends on the size of the local region considered and the quality of the image will degrade as the size of the local region increases. Experimental results show good quality preservation when the sizes of the local region are 3 × 3, 4 × 4, 5 × 5 with the corresponding compression ratios less than or equal to 7/24, 1/5, 13/100 respectively. A comparison with discrete cosine transform is given here and shows that the new technique produces better quality in most cases.     

High Moment Partial Sum Processes of Residuals in ARMA Models and their Applications

Abstract. In this article, we study high moment partial sum processes based on residuals of a stationary autoregressive moving average (ARMA) model with known or unknown mean parameter. We show that they can be approximated in probability by the analogous processes which are obtained from the i.i.d. errors of the ARMA model. However, if a unknown mean parameter is used, there will be an additional term that depends on model parameters and a mean estimator. When properly normalized, this additional term will vanish. Thus the processes converge weakly to the same Gaussian processes as if the residuals were i.i.d. Applications to change‐point problems and goodness‐of‐fit are considered, in particular, cumulative sum statistics for testing ARMA model structure changes and the Jarque–Bera omnibus statistic for testing normality of the unobservable error distribution of an ARMA model.     

置换型flow—shop控制的一些新结果

提出置换型ｆｌｏｗ－ｓｈｏｐ控制的新方法，并与文献「１」提出的基于极大代数模型的方法进行了比较，表明该方法比极大代数模型的方法更，所得结果有进一步扩大且更有实际意义，并通过实例分析证明了这一点。     

Self-organization of a 2D lattice on a surface of Ge single crystal after irradiation with Nd:YAG laser

Experimentally observed self-organization of a 2D lattice on the surface of Ge single crystal after irradiation by pulsed Nd:YAG laser is reported. The 2D lattice consists of nano-size hills arranged in a pattern of C_6i point group symmetry and is characterized by translational symmetry with the period of 1 μm. Calculations of time-dependent distribution of temperature in the bulk of the Ge sample are presented to explain the phenomenon. The calculations show that overheating of the crystal lattice occurs at laser radiation intensities exceeding 30 MW/cm². According to synergetic ideas, the presence of the non-equilibrium liquid phase of Ge and a huge gradient of temperature (∼3×10⁸ K/m) can lead to self-organization of the 2D lattice similar to Benard cells.     

蟒河口水库坝址岩体结构面直剪试验研究

岩体结构面的原位试验及其结果研究分析为设计部门提供更为可靠的资料.同时也为水利枢虹的设计,施工提供依据.本文在对蟒河口水库埂址岩体结构面进行直剪试验的基础上,分析岩体沿结构面的破坏机理,统计分析得到了抗剪断强度、残余抗剪强度.为水库大坝设计提供了可靠资料.