有限阿贝尔群同构的一个判定算法

给出了有限阿贝尔群同构的一个判定算法.     

平面应力状态分析中任意两截面上应力的新解法

在乎面应力状态分析中，通过取出受力构件内某点的应力状态，便可以求出任意斜截面上的应力和主应力，从而对复杂受力构件作强度计算。这是单元体上两微面间相互垂直的特殊情况下进行的。当两微面相互不垂直时，求解未知应力就比较因难。本文经过研究，找出了任意两截面上应力之间的关系，并研究用应力圆表示。这对求解复杂受力构件内任意两截面上的应力，带来较大的方便，提供了一个新的方法，并举例说明它的应用。     

Logistic映射在图像加密中的应用

分析了logistic映射的稳定点随参数变化的特性及其混沌特征,将logistic映射产生的混沌序列应用于图像加密/解密之中.设计的算法采用了两种不同表达方式的logistic映射所产生的两列混沌序列对图像进行加密.基于这种算法的混沌加密系统具有双参数,对初值极端敏感和不可预测性等优点.计算机仿真实验结果也表明了这种系统具有良好的安全性.     

The influence of high-stakes testing on teacher self-efficacy and job-related stress

In the United States, teachers’ job-related stress and self-efficacy levels across all grades are influenced in some manner by the demands of high-stakes testing. This sequential mixed-methods study aimed at examining the dynamics among assigned subject matter, teacher job-related stress, and teacher self-efficacy in a large south-eastern Texas school district. Quantitative data were collected via the High Stakes Testing on Self-Efficacy and Teacher Stress Survey from a convenience sample of 145 teachers, while qualitative data were gathered during focus-group sessions at the elementary, middle and high school levels. Findings indicated that assigned subject matter did not influence teacher self-efficacy, but did influence teachers’ job-related stress. Additionally, a relationship was found to exist between teacher job-related stress and teacher self-efficacy. Teachers reported lack of time, modifications to curriculum, and testing of special education populations as contributions to their job-related stress, and school leadership and educational triage as impacting their teacher self-efficacy.     

矮塔斜拉桥施工应力监测分析

通过对一座矮塔斜拉桥施工过程中的应力监测,指出了应力测试中存在误差的影响因素,结合工程实例对误差产生的原因进行了分析.针对实测应力与理论值的差别,得到了一些有益的结论.     

语言测试与外语教学

通过对语言测试理论发展历程的回顾，阐述了语言测试发展与外语教学发展的关系，指出语言测试是外语教学的重要组成部分，是衡量外语教学成效和提高外语教学质量的重要手段，是为教学服务的。充分发挥语言测试对教学的正面反拨作用，可促进外语教学，提高教学质量。最后，对大学英语测试制度和评估体系的改革提出了建设性的意见。     

Offshore and onsite placement testing for English pathway programmes

English language programmes provide established pathways for international students seeking university admission in countries such as Australia and the United Kingdom. In order to refer international applicants to appropriate levels and durations of English language support prior to matriculation into their main course of study, pathway providers need effective and efficient language assessment tools. This report evaluates the effectiveness of an online vocabulary knowledge test as an index of English proficiency for university English pathway programme applicants (N = 177). The Timed Yes/No (TYN) test measures vocabulary recognition size and speed in a time- and resource-effective format. Test results were correlated with performance on a comprehensive placement test consisting of speaking, writing, reading and listening components. The predictive validity of word recognition accuracy (a proxy for size) and response time (a measure of efficiency) for placement test outcomes were examined independently and in combination. The TYN test scores’ sensitivity at predicting comprehensive placement test scores were assessed using a cut-score analysis resulting in an identification accuracy rate ranging from 76 to 86% for five critical band scores. The potential use of the online vocabulary-screening test for measuring international students’ English language proficiency is discussed in terms of reliability, validity, speed, usability and cost-effectiveness in onsite and offshore testing conditions.     

A method for predicting critical load evaluating adhesion of coatings in scratch testing

INTRODUCTIONHardceramicfilmsdepositedbychemicalva pordeposition (CVD)andphysicalvapordeposi tion (PVD)techniqueshadbeenwidelyappliedinindustry .Coatingadhesionisaveryimportantpropertyforevaluatingthecoatingquality.Themethodevaluatingtheadhesionstrengthoft…     

A method for predicting critical load evaluating adhesion of coatings in scratch testing

In this paper based on the experiment principle of evaluating adhesion property by scratch testing, the peeling mechanism of thin films is discussed by applying contact theory and surface physics theory. A mathematical model predicting the critical load is proposed for calculating critical load as determined by scratch testing. The factors for correctly evaluating adhesion of coatings according to the experimental data are discussed.     

函数列一致收敛的一个充要条件

一致收敛的判别法对于函数列分析性质非常重要,Dini判别法是常见的判别方法,但它要求的条件相当强,不具普遍性．文章从点列角度出发给出函数列一致收敛的一个充要条件,并举例阐述其对判断是否一致收敛的有效性。     

基于混沌的OTP移动商务身份认证方案设计与实现

随着3G时代的到来移动电子商务以其随身移动、方便快捷、省时高效、利润丰厚等特点,成为电子商务新的发展方向,但移动电子商务的身份认证问题却成为了制约其快速发展的重要瓶颈。为解决上述问题,作者在现有身份认证技术的基础上,结合移动电子商务自身的特点,应用基于一次性口令（OTP）认证技术,融入独特的混沌HASH加密方式,提出了在移动商务环境下的OTP身份认证方案。该方案包含了用户注册、双向认证和敏感信息安全存储等内容。与传统身份认证方案相比,该方案更多的考虑了移动商务的安全性要求以及移动设备的技术局限性。符合移动商务自身特点,身份认证过程安全高效。     

虚拟仪器通用测试平台的研制及应用

把测试技术和计算机技术有机地结合起来，研制了用于实验教学的虚拟仪器通用综合测试平台。该平台包括有激励和测量的综合仪器功能，能在计算机的控制下完成自动测试实验，在此平台的基础上，建设了实验教学系统和实验教学环境，进行实验教学内容和方法的改革，开设出综合性、设计性实验，在本科生实验教学和实践能力的培养中取得了较好的效果。     

Weekly self-efficacy and work stress during the teaching practicum: A mixed methods study

The purpose of this longitudinal mixed methods study was to examine the development of self-efficacy and work stress of pre-service teachers during a teaching practicum. Participants were 150 pre-service teachers who completed eight weekly electronic surveys during their two-month final practicum in a Canadian teacher education program. The study investigates the patterns of self-efficacy and work stress during a critical period in the formation of new teachers. Latent growth curve analysis revealed a pattern of significantly increasing self-efficacy and significantly decreasing stress, although the trajectories were independent of each other. Qualitative analysis of multiple collective cases highlighted the variability of self-efficacy and stress patterns within the practicum experience, and underscored the critical influence of relationships with mentor teachers on self-efficacy and stress.     

A new algorithm for computing the convex hull of a planar point set

When the edges of a convex polygon are traversed along one direction,the interior of the convex polygon is always on the same side of the edges. Based on this characteristic of convex polygons,a new algorithm for computing the convex hull of a simple polygon is proposed in this paper,which is then extended to a new algorithm for computing the convex hull of a planar point set. First,the extreme points of the planar point set are found,and the subsets of point candidate for vertex of the convex hull between extreme points are obtained. Then,the ordered convex hull point sequences between extreme points are constructed separately and concatenated by removing redundant extreme points to get the convex hull. The time complexity of the new planar convex hull algorithm is O(nlogh) ,which is equal to the time complexity of the best output-sensitive planar convex hull algorithms. Compared with the algorithm having the same complexity,the new algorithm is much faster.     

基于转向的Logit网络分配算法实现与比较测试

为了评价基于转向的Logit网络分配算法(TALL)的实用性和高效性,在分析TALL算法过程的基础上,运用C++实现了TALL算法,并与传统的Dial算法+网络扩展法进行比较测试.TALL算法运用弧标号最短路径搜索、双向星形表和Deque结构,直接对道路网络进行流量分配,而不像Dial算法要在扩展后的路网上应用.在实际...     

A new heuristic algorithm for general integer linear programming problems

1 Introduction ? Since the cutting plane method [1] and branch-and- bound principle [2] were developed as two types of efficient approaches for integer linear programming problems, how to improve them or to find new algorithms more efficient has become an…     

论真理标准讨论的实践和理论意义

关于真理标准问题的大讨论的历史实践意义就在于为确立解放思想、实事求是的思想路线奠定了理论基础,从而也为２０年来的社会主义现代化建设道路的开创、为改革开放和社会主义市场经济体制的建立提供了前提。这场大讨论的理论价值就在于从理论上冲击了长期以来束缚人们思想的本本主义、教条主义,也冲击了传统的经学思维方式,并为适应现代社会需要的实践思维方式的形成产生了深远的影响     

A life course perspective of victimization,child welfare involvement,cumulative stress and mental health for mothers on probation and parole

Women involved in the criminal justice system experience multiple forms of adversity over their lifetimes. These events may include childhood abuse, involvement in the child welfare system as children, intimate partner violence victimization during adulthood, and punitive interactions with the child welfare system as mothers. Community supervision (e.g. probation or parole) entails particular stressors, such as obtaining basic needs and employment. A majority of women under community supervision also experience depression and anxiety. The current study used the Stress Process Model to investigate associations between childhood and adulthood stressors (including childhood abuse, intimate partner violence and child welfare system involvement), recent stressful life events, and symptoms of depression and anxiety for mothers (n = 348) on probation and parole. All of the mothers had experienced some form of childhood and/or adulthood victimization. Structural equation modeling was conducted to examine how childhood abuse, adulthood victimization, and child welfare system involvement as a child and a mother were associated with recent stressful life events and symptoms of depression and anxiety. Results indicated multiple direct and indirect relationships from childhood and adulthood stressors to mental health symptoms as women navigated probation and parole. For example, adverse childhood experiences were associated with elevated anxiety and depression symptoms via higher levels of recent stressful life events and adverse adulthood experiences. These findings highlight relationships between childhood abuse and adulthood factors and the mental health of mothers involved in the criminal justice system, with implications for theory, practice, and research.     

一种web应用回归测试的测试用例选择执行方法

为了提高web应用回归测试的效率,采用了控制流图和贪心算法.以页面为基本单位,通过构造web应用的控制流图,提出了一种基于控制流图的web应用回归测试的测试用例选择方法,该方法是一种安全的测试用例选择方法.在web应用回归测试的测试用例执行中,根据web应用中请求序列的特点,采用了最小化技术并考虑测试用例的优先级,提出了一种改进的贪心算法对测试执行进行了优化.实验结果表明,该方法有效地减少了需要重测的用例数并且提高了测试执行的效率.     

测试技术实验教学改革与学生创新能力的培养

对比了中美高校在课程定位上的差别；从研究创新性实验与设计性实验两方面人手，对机械工程测试技术课程实验教学进行了改革，强调对学生创新能力、工程实践能力等综合素质的培养。