一般三维非齐次偏微分方程的可解性条件

给出了一般形式的三维非齐次偏微分方程的可解性条件,据此可省去繁琐的计算过程,直接判断其解的存在性.可将此条件应用于晶体生长过程中的类似模型.     

英语中的对偶和对照修辞初探

对偶和对照是两种常见的修辞方式，但在英语和汉语中又不尽相同。在英语里，对偶和对照可由主语、谓语、表语、宾语、介词宾语、状语、定语从句、短语等九种方式构成。恰当地运用对偶和对照，可以增添语气的鲜明性，起到加强语气的作用。     

部分积累制养老保险模式存在问题分析

养老保障制茺是我国基本经济社会制度的重要组成部分，养老保障制度的建立与完善，将对经济社会发展起到积极的促进作用，反之也有可能成为经济社会发展的桎梏。本文首先对部分积累制养老保险模式进行了财务分析，阐述了该养老保险模式存在的主要问题，并提出了相应的解决对策。     

Schrdinger方程单内点精细积分法与差分法比较研究

可用单内点子域精细积分法求解Schrdinger方程初值问题。当单内点精细积分中的传递函数即指数函数用Taylor展开式的一阶近似来替代时,精细积分转化为差分方程。文章研究了这一对应关系。各种常见差分格式均找到了对应的单点精细积分格式,并在单点精细积分一般公式中得到了统一表达式。     

具饱和信号传输函数的二元离散神经网络收敛性与周期解的存在性

利用Lyapunov函数和Lasalle不变集原理讨论了一类具标准饱和信号传输函数的二元离散神经网络模型,得到了系统的稳定性和周期解的存在性等相关结论,改进了有关结果.     

静态变量与静态数据成员

本文从作用域和生命周期的角度解析了静态全局变量、静态局部变量、静态数据成员的含义，指出了它们本质上的特点和区别。     

关于二元函数可微条件的再探讨

给出了较弱条件下的二元函数可微的一个新定理及其证明.     

Inter-subject comparability of examination standards in GCSE and GCE in England

Results from Rasch analysis of GCSE and GCE A level data over a period of four years suggest that the standards of examinations in different subjects are not consistent in terms of the levels of the latent trait specified in the Rasch model required to achieve the same grades. Variability in statistical standards between subjects exists at both individual grade level and the overall subject level. Findings from this study are generally consistent with those from previous studies using similar statistical models. It has been demonstrated that the alignment of statistical standards between subjects based on the Rasch model would likely result in substantial change in performance standards of the examinations for some subjects evidenced here by significant changes in grade boundary scores and grade outcomes. It is argued that the defined purposes of GCSE and A level qualifications determine how their results should be interpreted and reported and that the existing grading and results reporting procedures are appropriate for supporting these purposes.     

偏微分方程在图像处理中的应用

低级的图像处理一直是制约计算机视觉发展的重要因素。由于涉及的数学理论很浅,经典的图像处理一直采用简单的启发式方法,虽偶能产生立竿见影的效果,但却有着致命的缺陷:我们不知道为什么、什么情况下该算法能奏效,而什么时候、为什么它又会失灵。近年来研究表明,偏微分方程(PDE)理论可为图像处理提供统一的理论框架,已在多个图像处理领域取得经典算法无法比拟的效果。文章首先介绍了基于PDE的图像处理方法的发展历程及相关理论背景,重点分析了其在图像恢复领域中的应用。     

Modeling Partial Knowledge on Multiple‐Choice Items Using Elimination Testing

Single‐best answers to multiple‐choice items are commonly dichotomized into correct and incorrect responses, and modeled using either a dichotomous item response theory (IRT) model or a polytomous one if differences among all response options are to be retained. The current study presents an alternative IRT‐based modeling approach to multiple‐choice items administered with the procedure of elimination testing, which asks test‐takers to eliminate all the response options they consider to be incorrect. The partial credit model is derived for the obtained responses. By extracting more information pertaining to test‐takers’ partial knowledge on the items, the proposed approach has the advantage of providing more accurate estimation of the latent ability. In addition, it may shed some light on the possible answering processes of test‐takers on the items. As an illustration, the proposed approach is applied to a classroom examination of an undergraduate course in engineering science.