Nonparametric iterative estimation of multivariate binary density

In this paper, an iterative estimate of the multivariate density is proposed when the variables are binary in nature. Some properties of this estimate are also discussed. Finally, applications of this estimate are discussed in the areas of pattern recognition and reliability.     

污染环境中三维竞争系统的生存阈值

本文用积分均值法，首次讨论了带有毒素影响的三维竞争系统的Lotka－Volterra模型，得到了各种群平均持续生存与绝灭的阈值．文中所得结论对环境污染以及生物种群影响的理论研究和实际应用有重要意义．文[5,6]的主要结论包含在本文的结果中．     

对不完全事后分层的估计

事后分层估计量是抽样调查中经常用到的一种估计方法。在使用多个分类变量对样本进行交叉事后分层时,边缘总值已知、格子总值未知的不完全事后分层问题是估计时又常面临的情况。本论文将对这一情况进行系统的总结,给出两个经典的估计量:搜索比率估计量和广义搜索比率估计量。     

CHEBYSHEV PSEUDOSPECTRAL-HYBRID FINITE ELEMENT METHOD FOR THREE-DIMENSIONAL VORTICITY EQUATION

In this paper,Chebyshev pseudospectral-finite element schemes are proposed for solving three dimensional vorticity equation.Some approximation results in nonisotropic Sobolev spaces are given.The generalized stability and the convergence are proved strictly.The numerical results show the advantages of this method.The technique in this paper is also applicable to other three-dimensional nonlinear problems in fluid dynamics.     

数理方程教学方法探讨

旨在通过教学实践体会来探讨数理方程课的教学方法.主要在分析课程特点、挖掘学生学习难点的基础上,从授课内容和思路、理论结合实际、培养学生学习思想、教学手段等多方面论述了提高数理方程课程教学质量的教学方法,同时结合教学实践列举多个数理方程的教学实例来说明锻炼学生能力的途径.     

A class of exact solutions and physical behaviour of magnetic field lines in plasma column

Using hodograph and Legendre transformation functions the basic equations are recast in terms of this function, and the conditions which this function should satisfy are stated. Several applications of this method are considered, and the geometry of magnetic field lines is discussed.     

特定阶的子群都同构且交换的有限p-群

研究某些子群同构的有限p-群是很有趣的.例如,Hermann和Mann都曾研究过极大子群都同构的有限p-群,但这类群的结构非常复杂,到现在人们都没能给出其分类.研究了特定阶的子群都同构且交换的有限p-群,并给出其分类.     

All finitely axiomatizable subframe logics containing the provability logic CSM_{0} are decidable

In this paper we investigate those extensions of the bimodal provability logic (alias or which are subframe logics, i.e. whose general frames are closed under a certain type of substructures. Most bimodal provability logics are in this class. The main result states that all finitely axiomatizable subframe logics containing are decidable. We note that, as a rule, interesting systems in this class do not have the finite model property and are not even complete with respect to Kripke semantics. Received July 15, 1997     

Preference, Production and Performance in Data Envelopment Analysis

This paper attempts to provide a systematic approach to the DEA model building. To this end, we try to identify some essential aspects of DEA modelling. Three key building blocks in a DEA model are identified: they are preference order, production possibility set and performance measure. It is shown that the preferences and performance measurements used in the standard DEA models are only particular examples in this framework. It is also illustrated in this work that this methodology is useful in building new DEA models to handle nonstandard applications such as those involve non-Pareto preferences or undesirable inputs-outputs.     

Numerical Simulation for Convection-Diffusion Problem with Periodic Micro-Structure

In this article, the convection dominated convection-diffusion problems with the periodic micro-structure are discussed. A two-scale finite element scheme based on the homogenization technique for this kind of problems is provided. The error estimates between the exact solution and the approximation solution, of the homogenized equation or the two-scale finite element scheme are analyzed. It is shown that the scheme provided in this article is convergent for any fixed diffusion coefficient 5, and it may be convergent independent of δ under some conditions. The numerical results demonstrating the theoretical results are presented in this article.     

Optimal electronic musical instruments

For many musical instruments, a musician depresses various combinations of keys in order to play the notes in the instrument’s range. For traditional (or acoustic) instruments of this type (e.g., woodwinds and most brass), the ways in which the combinations of keys can be assigned to the notes are limited by physics. However, for electronic instruments of this type, there are essentially no such limitations. In this paper, we exploit this freedom and present several designs for electronic instruments which are optimally easy to play; that is, the total movement of the fingers when playing some common sequences of notes (i.e., various, general collections of scales) is minimized. Our designs are built upon Gray codes, which are used in digital communications.     

Minimal representation of insurance prices

This paper prices insurance contracts by employing law invariant, coherent risk measures from mathematical finance. We demonstrate that the corresponding premium principle enjoys a minimal representation. Uniqueness–in a sense specified in the paper–of this premium principle is derived from this initial result. The representations are derived from a result by Kusuoka, which is usually given for nonatomic probability spaces. We extend this setting to premium principles for spaces with atoms, as this is of particular importance for insurance.Further, stochastic order relations are employed to identify the minimal representation. It is shown that the premium principles in the minimal representation are extremal with respect to the order relations. The tools are finally employed to explicitly provide the minimal representation for premium principles, which are important in actuarial practice.     

Penalty methods in nonlinear programming (survey)

In this paper general interior and exterior penalty methods are considered and their essential properties are summarized. Penalty-shifting methods are also contained in this survey.     

近程空中目标航路研究

本文在等加速俯冲飞行假定下,分析了近程空中目标航路的特点,并据此提出了目标航路模型.经过投影变换,把目标航路模型转化为二次函数,从而使目标航路的滤波及预报问题得到简化,采用弟推最小二乘(RLS)原理,给出了目标航路的滤波器及预报器,最后,对本文方法进行了仿真,并对仿真结果进行了分析.     

近程空中目标航路研究

本文在等加速俯冲飞行假定下，分析了近程空中目标航路的特点，并据此提出了目标航路模型．经过投影变换，把目标航路模型转化为二次函数，从而使目标航路的滤波及预报问题得到简化．采用递推最小二乘（ＲＬＳ）原理，给出了目标航路的在线滤波器及预报器．最后，对本文方法进行了仿真，并对仿真结果进行了分析．     

Quasi-particle theory of optical soliton interaction

The intra-channel collision of optical solitons, with non-Kerr law nonlinearities, is studied in this paper by the aid of quasi-particle theory. The perturbations terms that are considered in this paper are both of Hamiltonian as well as non-Hamiltonian type. The suppression of soliton–soliton interaction, in presence of these perturbation terms, is achieved. The nonlinearities that are studied in this paper are Kerr, power, parabolic and dual-power laws. The numerical simulations support the quasi-particle theory.     

The uniqueness of an entire function sharing a small entire function with its derivatives

In this paper, we prove a theorem on the growth of a solution of a linear differential equation. From this we obtain some uniqueness theorems concerning that a nonconstant entire function and its derivatives sharing a small entire function. The results in this paper improve many known results. Some examples are provided to show that the results in this paper are the best possible.     

The part families problem in flexible manufacturing systems

Parts grouping into families can be performed in flexible manufacturing systems (FMSs) to simplify two classes of problems: long horizon planning and short horizon planning. In this paper the emphasis is on the part families problem applicable to the short horizon planning. Traditionally, parts grouping was based on classification and coding systems, some of which are reviewed in this paper. To overcome the drawbacks of the classical approach to parts grouping, two new methodologies are developed. The methodologies presented are very easy to implement because they take advantage of the information already stored in the CAD system. One of the basic elements of this system is the algorithm for solving the part families problem. Some of the existing clustering algorithms for solving this problem are discussed. A new clustering algorithm has been developed. The computational complexity and some of the computational results of solving the part families problem are also discussed.