电路系统的参数识别问题及其数值处理

设一个电路在阶跃电压激励下，测出其输出电流或输出电压响应波形，能否确定该电路的等效参数Ｌ、Ｒ和Ｃ的值？这是一个电路系统的逆问题，也是一个识别问题。准确地识别出这些参数的数值，对于电路系统评价和分析设计以及对于实际应用都有着十分重要的意义。本文给出了处理这类问题的有效方法，即采用数值逼近和最小二乘原理，得到了令人满意的结果     

Parallel-batching scheduling of deteriorating jobs with non-identical sizes and rejection on a single machine

This paper studies the bounded parallel-batching scheduling problem considering job rejection, deteriorating jobs, setup time, and non-identical job sizes.     

Prediction of ventricular fibrillation based on nonlinear multi-parameter

Ventricular fibrillation (VF) caused by myocardial ischemia is one of the leading factors of death attributed to cardiovascular diseases. It is particularly significant to predict VF and gain valuable time for clinic therapy. Five dogs are taken as the research objects and a VF model is introduced. The nonlinear characteristics of the ECGs before and after VF are investigated with nonlinear multi-parameter analysis methods, Gaussian kernel (GK) correlation estimation algorithm and Lyapunov exponent estimation algorithm. Correlation entropy h2 is also presented. The results indicate that there are three parameters which will change at the same time with the conditions of myocardial ischemia,and any changes of a single parameter may be caused by other factors and mislead the judgment. Multi-parameter analysis is more reliable to reveal the heart conditions, and to predict VF without misjudgments.     

关于线性规划问题无界最优解及最优解的一般表示法的研究

本文给出了一个具有一般性的线性规划问题存在无界最优解的充要条件,并绘出了线性规划问题最优解的更直观的一般表示法。     

实赋范数性空间内的Lp-正交

In this paper we have proved the theorem: Let p>1, and E be a real normed linear space, if the L^p-orthogonality in E satisfies one of the following conditions 1) homogeneity 2) additivity 3) x⊥_L^py implies x⊥_Jy 4) x⊥_Jy implies x⊥_L^py, then E is an abstract Euclidean space and there must be p=2. We also proved anR. C. James' result-If for every element x of a normed linear space E therecan be found a nonzero element orthogonal to x by Roberts' definition in each two dimensional linear subset containing x, then E is an abstract Euclidean space——which had not been proved. Finally, we point out that if one of the James′,L^p-,isosceles, Pythagorean and (α,β)-orthogonalities defined in E implies Roberts′ orthogonality then E is an abstract Euclidean space.     

体表电位图的测量与处理系统

本文叙述了一台以Intel 8086CPU为核心的微机处理系统,用以测量体表电位图。该系统具有64个模拟输入通道,采集人体胸廓表面的各点心电信号,经放大、A/D特换后送入微机系统,用插值法计算并在监示器上显示任意点的心电图和任一时刻約体表电位图。文末给出两名正常人的心电体表电位图。     

A study on responses of soil erosion and sediment yield to closing cultivation on sloping land in a small catchment using ^137Cs technique in the Rolling Loess Plateau, China

By comparison of volumes and ^137Cs Contents of the deposited sediments before and after 1993,changes of specific sediment yields and relative sediment contributions from the gully area and from the inter gully area after closing cultivation on the later area on a small catchment of Zhaojia Gully,in the Rolling Loess Plateau,are analyzed in this paper.Closing cultivation in a large scale has not resulted in decrease but increase of specific sediment yield and the relative sediment contribution of the inter-gully area,and in increase of the sediment yield and the contribution of the gully area,for a short term.The mean specific sediment yield of 29650 t km^-2a^-1 of 1994-1996 in the catchment was 2.2 times the average value of 13413 t km^-2 a^-1 for a long term.The specific sediment yield of the inter-gully area decreased from the 14335t km^-2a^-1 in 1994 to 7034 t km^-2 a^-1 in 1995 and 3517 t km^-1a^-1 in 1996 which was much greater than the value of 21118 t km^-2 a^-1 before 1993.The relative sediment contribution from the inter-gully area decreased form 23% in 1994 to 15% in 1995 and 6% in 1996,while the contribution from the gully area increased form 77% in 1994 to 85% in 1995 and 94% in 1996.It is suggested that compacting of ploughed soils resulted in increasing of the erosion resistance but in decreasing of the precipitation infiltration,therefore,the soil erosion reduced but the runoff amount increased on the inter-gully area.Increase of delivering runoff from the inter-gully area to the gully area should result in activeness of gully erosion and mass movements,consequently,in increase of the total sediment yield from the catchment.     

Sediment source identification by using ^137Cs and ^210pb radionuclides in a small catchment of the Hilly Sichuan Basin, China

The Hilly Sichuan Basin is one of the most populous agricultural regions in the Upper Yangtze River Basin and has an area of about 105000 km2. Cropland ratios and population densities vary between 0.3 and 0.7 and be-tween 400 and 800 people/km2, respectively, in the Si-chuan basin. The basin is considered as one of the most severely eroded regions in the Upper Yangtze River Basin as well in China. Soil erosion rates were reported mostly to be greater than 5000 t·km-2·a-1 by the first st…     

方程u_(tt)=u_(xxt)+f(u_x)_x初边值问题的差分法

The finite difference method is considered for the followinginitial-boundary-value problem: arrayllutt=uxxt+f(ux)x, & (x,t) QT, u(x,0) =(x), & x ［0,1］, ut(x,0) = (x), & x ［0,1］, u(0,t) =u(1,t) =0, & t ［0,T］,array. where f(s),(x) and (x) are given functions;QT=［0,1］ ［0,T］. The convergence of the finite difference schemesis verified by discrete functional analysis methods and prior estimationtechniques.     

基于独立分量谱相关方法的重力固体潮信号潮汐谐波分析

为了提取重力固体潮信号各谐波分量间能量差异较大的谐波分量,该文在利用独立分量分析实现重力固体潮信号的加性分解,再利用谱相关分析独立分量间的谱相关特性进行分析,揭示了各谐波间的调制关系.同时,通过对独立分量间的自相关谱和互相关谱的分析,论证了在自相关谱中,能量大的谐波分量被凸显,能量小的谐波分量被抑制,而在互相关谱中,能量较小的谐波分量能更好地凸显出来.结果表明,互相关谱更能够揭示重力固体潮信号中弱的潮汐谐波分量及其调制关系.