Reliability based multiobjective optimization for design of structures subject to random vibrations

Based on a multiobjective approach whose objective function （OF） vector collects stochastic reliability performance and structural cost indices, a structural optimization criterion for mechanical systems subject to random vibrations is presented for supporting engineer＇s design. This criterion differs from the most commonly used conventional optimum design criterion for random vibrating structure, which is based on minimizing displacement or acceleration variance of main structure responses, without considering explicitly required performances against failure. The proposed criterion can properly take into account the design-reliability required performances, and it becomes a more efficient support for structural engineering decision making. The multiobjective optimum （MOO） design of a tuned mass damper （TMD） has been developed in a typical seismic design problem, to control structural vibration induced on a multi-storey building structure excited by nonstationary base acceleration random process A numerical example for a three-storey building is developed and a sensitivity analysis is carried out. The results are shown in a useful manner for TMD design decision support.     

标准抑或标准化——高校教学质量评价的再审视

目前普通高校教学质量评价越来越以量化的标准作为评价的主要依据,出现了片面倚 靠标准等从标准走向标准化的现象。教学质量评价的标准化现象可能会遏制教学过程中的创造性,忽视多元差异,易造成教师的职业倦怠等。在这种情境下,应理性认知教学质量评价标准,更贴近 教学实际,由院系等教学单位根据学校定位、专业人才培养目标以及社会对毕业生能力素质的要求 自主制定专业教学质量标准、课程教学质量标准,使其更具有动态性和多元性,切实减少量化倾向,理性运用教学质量标准的评价结果。     

Some Parent-Child Relationships as Shown in Clinical Case Studies

The identification and composition of four subtests constituting the major areas of competence of English as a foreign langauge is reported, largely based on a study of the literature. A 160-item, four-choice test was used to obtain a number of reliability and validity indices. It was found that grammar was the most reliable and the most valid component when based on total test scores as the criterion, where-as translation was lowest on these two measures. The opposite trend was observed with Grade Point Average as the criterion, whereas the third criterion, writing ability, was found to correlate highest with listening comprehension, which was also found to contribute to the highest unique nonchance variance of the four components. These findings and their explanation are discussed.     

评价考试质量的新指标：决策一致性和决策准确性

在把考生分成几个分数等级的标准参照性考试中,除传统的信度系数外,决策一致性和决策准确性是两个重要的考试质量评价指标。本文介绍决策一致性和决策准确性的定义、研究发展、和几种常用的基于经典测量理论和项目反应理论的估计方法包括Subkoviak方法、Huynh方法、Livingston-Lewis方法和Rudner方法。     

On the generalizability of school-level performance assessment scores

This study illustrates how generalizability theory can be used to evaluate the dependability of school-level scores in situations where test forms have been matrix sampled within schools, and to estimate the minimum number of forms required to achieve acceptable levels of score reliability. Data from a statewide performance assessment in reading, writing, and language usage were analyzed in a series of generalizability studies using a person: (school x form) design that provided variance component estimates for four sources: school, form, school x form, and person: (school x form). Six separate scores were examined. The results of the generalizability studies were then used in decision studies to determine the impact on score reliability when the number of forms administered within schools was varied. Results from the decision studies indicated that score generalizability could be improved when the number of forms administered within schools was increased from one to three forms, but that gains in generalizability were small when the number of forms was increased beyond three. The implications of these results for planning large-scale performance assessments are discussed.     

An Empirical Keying Approach to Academic Prediction with the Guilford-Zimmerman Temperament Survey,

The present study was conducted to establish a scoring key for the Guilford Zimmerman Temperament Survey appropriate for predicting academic performance. To maximize reliability of criterion data, academic performance was operationally defined as cumulative college grade point average based on a minimum of four semesters’ course work. The scoring key developed was predictive of academic performance (cross validated r = .39, p <.01). The magnitude of the relationship between scores on this key and cumulative grade point average compares favorably with the validities reported for the widely used academic aptitude tests in predicting the same criterion. Lesser relationships were observed between scores on the ten publisher-supplied scales and college grades. Results point to the utility of non-cognitive measures in predicting academic performance, particularly when keys tailored to the specific situation are empirically derived. Suggestions for future research are advanced.     

码元级的RS码快速软译码

通过比较几种码元可靠性值计算方法，提出了准确率较高的最小值法。基于RS码并行译码算法，将RS码移位并行译码算法作为软判决译码的代数译码方法，直接利用每个码元的可靠性值，确定试探位置，计算错误图样的软重量。模拟结果表明该算法与传统的Chase-2算法相比，译码速度得到了很大提高。     

门座起重机RCM维修决策系统设计

应用面向对象高级语言C#和SQL Server 2005数据库,采用风险矩阵法、模糊层次分析法、根本原因分析法、综合决策法、逻辑决策法等方法,开发一套基于RCM技术,能够完成港口门座起重机的基础信息管理,以风险为基础,具有良好目标性的维修决策系统,根据用户选择的影响因素来确定其零部件的维修方式和最佳维修周期,以提高机械设备的可靠性和安全性,为企业提供优化、系统、科学的维修决策支持。     

Estimating the Consistency and Accuracy of Classifications Based on Test Scores

This article presents a method for estimating the accuracy and consistency of classifications based on test scores. The scores can be produced by any scoring method, including a weighted composite. The estimates use data from a single form. The reliability of the score is used to estimate effective test length in terms of discrete items. The true-score distribution is estimated by fitting a 4-parameter beta model. The conditional distribution of scores on an alternate form, given the true score, is estimated from a binomial distribution based on the estimated effective test length. Agreement between classifications on alternate forms is estimated by assuming conditional independence, given the true score. Evaluation of the method showed estimates to be within 1 percentage point of the actual values in most cases. Estimates of decision accuracy and decision consistency statistics were only slightly affected by changes in specified minimum and maximum possible scores.     

Consistently inconsistent: An examination of the variability in the identification of emotional disturbance

The federal definition of emotional disturbance (ED) has been heavily criticized as vaguely defined and poorly operationalized yet there has not been a formal analysis of the reliability of the ED criteria. This study examined the reliability of the federal criteria for a special education designation of ED. A total of 179 school psychologists reviewed a mock special education report, made an eligibility determination, and provided information about their eligibility decision. In all, 56 participants found the student met ED eligibility criteria using 16 different combinations of the five criteria. Krippendorff’s α, a statistic preferred for content analysis, was calculated as a measure of criterion reliability. Results indicated extremely poor reliability (α = 0.2011). These findings demonstrate the importance of redefining the existing criteria.     

Systematic Comparison of Decision Accuracy of Complex Compensatory Decision Rules Combining Multiple Tests in a Higher Education Context

This real‐data‐guided simulation study systematically evaluated the decision accuracy of complex decision rules combining multiple tests within different realistic curricula. Specifically, complex decision rules combining conjunctive aspects and compensatory aspects were evaluated. A conjunctive aspect requires a minimum level of performance, whereas a compensatory aspect requires an average level of performance. Simulations were performed to obtain students' true and observed score distributions and to manipulate several factors relevant to a higher education curriculum in practice. The results showed that the decision accuracy depends on the conjunctive (required minimum grade) and compensatory (required grade point average) aspects and their combination. Overall, within a complex compensatory decision rule the false negative rate is lower and the false positive rate higher compared to a conjunctive decision rule. For a conjunctive decision rule the reverse is true. Which rule is more accurate also depends on the average test reliability, average test correlation, and the number of reexaminations. This comparison highlights the importance of evaluating decision accuracy in high‐stake decisions, considering both the specific rule as well as the selected measures.     

The Quality of Local District Assessments Used in Nebraska's School-Based Teacher-Led Assessment and Reporting System (STARS)

A sample of 293 local district assessments used in the Nebraska STARS (School-based Teacher-led Assessment and Reporting System), 147 from 2004 district mathematics assessment portfolios and 146 from 2003 reading assessment portfolios, was scored with a rubric evaluating their quality. Scorers were Nebraska educators with background and training in assessment. Raters reached an agreement criterion during a training session; however, analysis of a set of 30 assessments double-scored during the main scoring session indicated that the math ratings remained reliable during scoring, while the reading ratings did not. Therefore, this article presents results for the 147 mathematics assessments only. The quality of local mathematics assessments used in the Nebraska STARS was good overall. The majority were of high quality on characteristics that go to validity (alignment with standards, clarity to students, appropriateness of content). Professional development for Nebraska teachers is recommended on aspects of assessment related to reliability (sufficiency of information and scoring procedures).     

The effects of discourses in regional contexts on the development of curriculum-based literacy standards for adolescents in schooling: a comparative study of South Australia and Ontario

This study analyses how discourses in regional contexts affect the development of curriculum-based literacy standards for adolescents in schooling. A comparative case-study research design enabled the influences of discourses at the regional level to be analysed. The case studies include the development of curricula to define a minimum literacy standard for the final years of schooling for adolescents in Ontario, Canada, and South Australia, Australia. Critical discourse analysis of key texts associated with the development of literacy standards in each region reveals how globally shared meanings about standard setting for schooling interact with other discourses operating in local contexts to produce curricula that define literacy standards. The results indicate that, while a global discourse about standards-based reforms may be foregrounded in curriculum, locally generated discourses can challenge key ideas associated with a simplistic discourse about standards. Discourses about literacy in Ontario and South Australia contest the assertion that literacy at the end point of schooling can be defined as a basic competency and local meanings associated with literacy are emphasised within the curriculum for each location. Language choices, involving particularly lexical cohesion, complex noun groups and nominalisation, are used to ensure that local meanings inform literacy standards for the endpoint of schooling.     

博弈论的电子商务团购诚信问题

随着作为电子商务新模式的团购在中国快速兴起,信用问题不可避免的成为其发展的主要障碍。对博弈模型的分析说明了商家失信行为几乎是必然的建议通过尽快出台相关的法律法规,建立高效、统一、权威的信用声誉评价系统等方法以保证团购的信用。     

Reliability Estimates for Undergraduate Grade Point Average

Undergraduate grade point average (GPA) is a commonly employed measure in educational research, serving as a criterion or as a predictor depending on the research question. Over the decades, researchers have used a variety of reliability coefficients to estimate the reliability of undergraduate GPA, which suggests that there has been no consensus on the most appropriate model. This paper reviews the assumptions of different reliability models and examines the effect of violating these assumptions on reliability estimates of GPA. Using longitudinal semester GPA data for 62,122 students from 26 four-year institutions, the reliability estimates for semester, annual, and fourth-year cumulative GPA ranged between .60–.65, .75–.79, and .89–.92, respectively. Depending on the measure, up to eight different reliability coefficients were estimated. In general, different estimates resulted in minor differences even when the assumptions of the underlying models are not met; however, larger differences were observed for the fourth-year cumulative GPA analyses.     

医学生临床能力的测评与分析--七年制临床医学生临床技能考核的概化理论研究

为了科学、客观地评价七年制临床医学生的临床技能,我们应用新的教育测量理论——多元概化理论,对七年制临床医学生毕业前的内科临床技能考核结果进行分析研究。结果表明,临床技能考核总的可靠性指数为0．63725,绝对信噪比为1．75668,提示本次临床技能考核总的信度符合考核要求;临床思维能力和理论知识水平部分内容信度相对较高,也最能有效区分考生能力的差别;临床实践能力的信度较低;评分者素质与评分能力相对较好。多元概化理论能客观、科学地评价七年制医学毕业生临床技能考核,其分析结果对于提高及改进临床技能考核质量有较大帮助。     

Evaluation of Validity and Reliability for Hierarchical Scales Using Latent Variable Modeling

A latent variable modeling method is outlined, which accomplishes estimation of criterion validity and reliability for a multicomponent measuring instrument with hierarchical structure. The approach provides point and interval estimates for the scale criterion validity and reliability coefficients, and can also be used for testing composite or simple hypotheses about these coefficients. The proposed method is illustrated with a numerical example.     

Measuring Habituation in Infants: An Approach Using Regression Analysis

The effectiveness of different habituation criteria was examined by means of computer simulations. A criterion based on fitting a second-order polynomial regression function to the looking time data was described. This criterion produced more accurate estimation of looking times as well as higher experimental power for detecting novelty effects, compared to the traditional windowed running average criterion or to a criterion based on linear regression. The polynomial regression approach probably has this advantage because it utilizes all of the available looking time data, rather than just the data in the current windowed average, and because it is sensitive to nonlinear trends in looking time. This new habituation criterion is easy to implement on a laboratory computer, and it should increase session lengths by no more than one trial or so, compared to windowed average criteria. With regard to test-retest reliability, all of the habituation criteria that were evaluated appear to have low reliability on average, with high sample-to-sample variability. These undesirable reliability characteristics are attributable to the high variability of infants' attentional behavior.     

Construct Validity and Reliability of the Finnish Version of the Demand-Control Questionnaire in Two Samples of 1028 Teachers and 630 Nurses

The job demand-control (JDC) model has dominated research into occupational stress for the last 20 years. Two concepts lie at the core of the demand-control model: job demands and job control. Control is also referred to as decision latitude and the concept has two facets: decision authority and skill discretion. The purpose of the current study was to conduct an empirically correct specification of the key concepts of the JDC model. The Scandinavian version of an instrument assessing the key concepts of the model was used and the objective of the study was to test the validity and reliability of the Finnish version of the job content questionnaire (JCQ) among teachers and nurses. Altogether 1028 teachers and 630 nurses participated. Exploratory factor and confirmatory analyses were employed to assess the factorial structure of the Finnish version of the JCQ and to evaluate which factorial model fitted the data best. Analyses indicated a factor solution with two factors: job demands and decision authority. The confirmatory factor analyses supported the results from the exploratory factor analyses. The model which fitted the data best was the model with two oblique factors with the items measuring skill discretion removed. Based on the results of exploratory and confirmatory factor analyses it seems reasonable to measure job demands and control in this sample with two factors: demand and decision authority.     

Maximal Criterion Validity and Scale Criterion Validity: A Latent Variable Modeling Approach for Examining Their Difference

This article studies the difference between the criterion validity coefficient of the widely used overall scale score for a unidimensional multicomponent measuring instrument and the maximal criterion validity coefficient that is achievable with a linear combination of its components. A necessary and sufficient condition of their identity is presented in the case of measurement errors being uncorrelated among themselves and with a used criterion. An upper bound of the difference in these validity coefficients is provided, indicating that it cannot exceed the discrepancy between the maximal reliability and composite reliability indexes. A readily applicable latent variable modeling procedure is discussed that can be used for point and interval estimation of the difference between the maximal and scale criterion validity coefficients. The outlined method is illustrated with a numerical example.