彩色FED灰度等级的实现

提出场致发射显示器FED显示系统中256级灰度等级的两种实现方法,即脉冲宽度调制法(PWM法)和子场灰度显示法(ADS法),同时在这两种方法的基础上分别给出了具体实现的电路和原理,并参照CRT灰度等级测试方案对基于PWM的FED显示系统进行了灰度测试,最后对这两种方法进行对比分析。     

多核并行计算下的流量传感器流场模拟研究

多核并行小型集群系统给流量传感器流场模拟应用提供了方便可行的条件,文章将通过建立一个多核并行小型集群仿真系统为例来讨论多核并行计算对流量传感器流场模拟的支持,对其进行了测试,并实现了管道流量传感器流场的CFD模拟,取得较好结果。通过测试表明,我们的多核并行集群可扩展性能好,具有较高的并行计算性能,能满足一般并行计算的需要。     

非参数项目反应理论在小规模测验中的运用

单调匀质模型是非参数项目反应理论中使用最广泛的模型,它有三个基本假设,适用于小规模测验的分析。本研究使用MHM分析北京语言大学汉语进修学院某次测验,结果表明测验满足弱单维性假设与弱局部独立性假设,67个项目中有9个项目的量表适宜性系数低于0.3,需要修改或删除,删除后测验为中等强度的Mokken量表。另外,有2个项目违反了单调性假设,不符合Mokken量表的要求。     

‘Consider the Opposite’ – Effects of elaborative feedback and correct answer feedback on reducing confirmation bias – A pre-registered study

Unbiased reasoning is considered an essential critical thinking skill that students need to possess to face the future challenges in their work and life. Confirmation bias, which is the tendency to selectively attend to information that is consistent with held beliefs, presents a significant thread to unbiased reasoning. An effective strategy to reduce confirmation bias is the ‘consider-the-opposite’-strategy (COS). The central question of this pre-registered study was whether providing elaborative, worked example feedback after COS practice would lead to a better performance on previously practised and transfer tasks than correct-answer feedback. Participants were 132 university students who took a confirmation bias pre-test, watched an instructional video on COS afterwards and next received either worked example feedback or correct answer feedback on practice tasks, practised only, watched the instruction only or received no treatment. Finally, all participants took a learning test assessing their skill to avoid confirmation bias, and a transfer test assessing whether they could apply this acquired skill to problems containing other biases. Results revealed no differences on the learning test between both feedback conditions, but students who received feedback scored significantly higher on the confirmation bias problems than students who did not receive feedback. We carried out our pre-registered analysis plan, but due to the low reliability of particularly the pre-test, we carried out an additional exploratory analysis on subsets of post-test items and a subset of transfer test items. Results on learning revealed the same pattern as the planned analyses. However, we found no differences between any of the conditions on transfer.     

Rater Certification Tests: A Psychometric Approach

Rater training is an important part of developing and conducting large‐scale constructed‐response assessments. As part of this process, candidate raters have to pass a certification test to confirm that they are able to score consistently and accurately before they begin scoring operationally. Moreover, many assessment programs require raters to pass a calibration test before every scoring shift. To support the high‐stakes decisions made on the basis of rater certification tests, a psychometric approach for their development, analysis, and use is proposed. The circumstances and uses of these tests suggest that they are expected to have relatively low reliability. This expectation is supported by empirical data. Implications for the development and use of these tests to ensure their quality are discussed.     

μCOS＋EFSL文件系统移植研究与实现

文章分析了在X86平台保护方式下使用GNU工具链实现μCOS＋EFSL文件系统移植的技术要点;阐述了移植的关键步骤,以及在X86平台移植的具体实现方法.内容包括μCOS及EFSL文件系统的移植要点、EFSL RAM盘的创建、EFSL磁盘接口函数的设计与实现等.     

嵌固在软岩中水平承载桩计算宽度的研究

水平推力桩的受力状态是非常复杂的三维空间问题。本文针对嵌固在软质岩中的水平承载桩,就计算宽度问题进行了现场试验及弹塑性有限元程序计算分析两方面的研究。本文引入扩散角的概念,用此概念说明桩侧边长度对于计算宽度的影响,从而建立计算宽度的计算公式。     

Tests,Test Scores,and Constructs

In the service of educational accountability, student achievement tests are being used to measure constructs quite unlike those envisioned by test developers. Scores are compared to cut points to create classifications like “proficient”; scores are combined over time to measure growth; student scores are aggregated to measure the effectiveness of teachers, schools, and school districts; indices are created to measure college and career readiness. These and other new uses rely on derived scores created to measure new constructs. The field of educational and psychological measurement has largely ignored these significant, consequential measurement applications. The conceptual frameworks and analytical tools of educational and psychological measurement should be used to study such derived scores and the validity of their uses and interpretations.     

ARM μCOS自适应启动程序的设计与实现

文章阐述了在ARMS3C2410嵌入式平台下,μCOS自适应启动程序的设计原理与实现方法.该程序在Linux操作系统下使用GNUARM-Linux工具链实现;采用位置无关代码实现μCOS启动,自动识别启动位置,将整个系统装载到SDRAM高端;使用MMU技术,将中断向量映射到0xffff0000,实现＂高端中断＂;采用＂间接中断向量＂方法,将真正的中断处理程序入口设置在SDRAM中,因此可在μCOS中根据需要随时切换中断处理程序.在ARM μCOS中使用该程序,不仅可以通过vivi下载后由vivi引导运行,还可在ARM裸机上直接启动系统,无需任何改动.     

一种改进的虹膜内边缘定位算法

首先利用小尺度高斯低通滤波器对虹膜图像进行预处理,去除可能存在的眼睑和睫毛干扰;然后用Canny边缘检测算子得到虹膜的内边缘,通过自适应选取非极大值抑制的高阈值,并对不连续边缘进行修整,得到比较理想的虹膜内边缘;最后利用圆周上任意不共线的3点可以确定一组圆心及半径的参数的性质得到虹膜内边缘的圆心及半径,完成虹膜内边缘定位。实验结果表明,该算法可以比较准确地定位出虹膜的内边缘。     

Development of the self-directed learning skills scale

The purpose of this study was to develop a valid and reliable scale for assessing high school students’ self-directed learning skills. Based on a literature review and data obtained from similar instruments, all skills related to self-directed learning were identified. Next, an item pool was prepared and administered to 255 students from various high schools. To test the suitability of the gathered data, exploratory factor analysis was performed. The results revealed that there were correlations between the items, factor analysis could be conducted and nine factors were obtained. A confirmatory factor analysis (CFA) was performed concerning the quality of the factor structure. The results of the CFA confirmed the nine-factor solution. The final version of the scale has a nine-factor structure and includes a total of 40 items. This instrument uses a five-point Likert-type scale and was termed the Self-Directed Learning Skills Scale (SDLSS).     

用GNU工具链实现μCOS到ARM平台的移植

文章分析了在ARM平台上使用GNU工具链实现μCOS嵌入式内核移植的技术要点;阐述了移植的关键步骤,以及在ARM平台上移植的具体实现方法.内容包括操作系统引导及装载程序的设计、μCOS运行之前硬件环境的建立、μCOS与平台相关接口程序、串口通信程序及相关辅助性实用程序的设计等.     

极大规模词语搭配库的建造和构成分析

大规模词语搭配库的建造在自然语言处理领域的诸多方面都有着迫切的需求。本文利用哈工大、伯克利、斯坦福三所大学分别研制开发的三个句法分析器,对9年《人民日报》语料进行了句法分析,通过对三个分析结果的合并比对得到候选搭配;在此基础上通过参数及类型优选进一步提升搭配精度,最终得到规模约为136万的搭配型数据及相关统计信息并以此构建了词语搭配库。词语搭配库中包含了6种常见类型的搭配数据,并且保证了较好的正确率,可以为其它相关工作提供可靠的数据支持。     

The Contestant Perspective on Taking Tests: Emanations From the Statue Within

Views on testing—its purpose and uses and how its data are analyzed—are related to one's perspective on test takers. Test takers can be viewed as learners, examinees, or contestants. I briefly discuss the perspective of test takers as learners. I maintain that much of psychometrics views test takers as examinees. I discuss test takers as a contestant in some detail. Test takers who are contestants in high‐stakes settings want reliable outcomes obtained via acceptable scoring of tests administered under clear rules. In addition, it is essential to empirically verify interpretations attached to scores. At the very least, item and test scores should exhibit certain invariance properties. I note that the “do no harm” dictum borrowed from the field of medicine is particularly relevant to the perspective of test takers as contestants.     

Do college admissions counselors discriminate? Evidence from a correspondence-based field experiment

I design and implement a correspondence based field experiment to test for race and gender discrimination among college admissions counselors in the student information gathering stage. The experiment uses names to identify student race and gender, and student grade, SAT score, and writing differences to reflect varying levels of applicant quality. I find that counselors do not respond differently by race in most cases, but there are measurable differences in response/non-response and in the type of correspondence sent that favor female students. I also find that the quality of the student induces large differences in the type of response.     

Correlation between academic and skills-based tests in computer networks

Computing‐related programmes and modules have many problems, especially related to large class sizes, large‐scale plagiarism, module franchising, and an increased requirement from students for increased amounts of hands‐on, practical work. This paper presents a practical computer networks module which uses a mixture of online examinations and a practical skills‐based test to assess student performance. For widespread adoption of practical assessments, there must be a level of checking that the practical assessments are set at a level that examinations are set at. This paper shows that it is possible to set practical tests so that there can be a strong correlation between practical skills‐based tests and examination‐type assessments, but only if the practical assessment are set at a challenging level. This tends to go against the proposition that students who are good academically are not so good in a practice test, and vice versa. The paper shows results which bands students in A, B, C, and FAIL groups based on two online, multiple‐choice tests, and then analyses the average time these students took to complete a practical online test. It shows that there is an increasing average time to complete the test for weaker students. Along with this, the paper shows that female students in the practical test outperform male students by a factor of 25%.     

μCOS移植技术探究

文中以X86平台及ARM平台为例,分析了μCOS嵌入式内核移植的技术要点.内容包括X86平台及ARM平台硬件环境的简述、操作系统引导及装载程序的设计、μCOS运行之前硬件环境的建立、μCOS与平台相关接口程序、设备驱动程序、实用库函数的设计等.     

大学生网络成瘾及其焦虑水平的调查研究

为了对IAD者的有效心理治疗提供一定的理论基础及方法指导,采用纸笔测验对在校100名较喜好上网的大学生进行网络成瘾诊断测验及焦虑症自测并用SPSS11.0软件进行处理与分析。结果发现:(1)网络成瘾者与非成瘾者在焦虑水平上并未表现出显著性差异,但它在性别和焦虑水平上的交互作用却表现出很大的差异。(2)大学生网络使用者的行为特点和认知方式在焦虑水平上存在显著性差异。由此可见,大学生网络成瘾在性别和焦虑水平上表现出一定的差异,且影响其成瘾的因素也主要集中于行为和认知两维度上。     

A Factor Analysis of the Counseling-Orientation Preference Scale (COS)

As recommended by the authors of the Counseling-Orientation Preference Scale (COS), a factor analysis study was conducted to investigate the construct validity of the device. Data were collected from 686 respondents in 11 higher education institutions in the U.S. Means and standard deviations from this group and from two previously studied groups were reported. As might be expected from an instrument of 35 items divided into 7 subscales of 5 items each, the results indicated that items were not identified cleanly with the a priori placements used in the original construction. Basically, two major cluster groupings were found. Overall, some support for the construct validity of the COS was found; however, subscale interpretations must be made with caution. The utility of the COS and similar devices is in the self-study and reflection that is fostered in those who use them.