Cumulative correspondence analysis of ordered categorical data from industrial experiments

Most studies of quality improvement deal with ordered categorical data from industrial experiments. Accounting for the ordering of such data plays an important role in effectively determining the optimal factor level of combination. This paper utilizes the correspondence analysis to develop a procedure to improve the ordered categorical response in a multifactor state system based on Taguchi's statistic. Users may find the proposed procedure in this paper to be attractive because we suggest a simple and also popular statistical tool for graphically identifying the really important factors and determining the levels to improve process quality. A case study for optimizing the polysilicon deposition process in a very large-scale integrated circuit is provided to demonstrate the effectiveness of the proposed procedure.     

Analysis of robust design experiments with time-dependent ordinal response characteristics: a quality improvement study from the horticulture industry

An approach to the analysis of time-dependent ordinal quality score data from robust design experiments is developed and applied to an experiment from commercial horticultural research, using concepts of product robustness and longevity that are familiar to analysts in engineering research. A two-stage analysis is used to develop models describing the effects of a number of experimental treatments on the rate of post-sales product quality decline. The first stage uses a polynomial function on a transformed scale to approximate the quality decline for an individual experimental unit using derived coefficients and the second stage uses a joint mean and dispersion model to investigate the effects of the experimental treatments on these derived coefficients. The approach, developed specifically for an application in horticulture, is exemplified with data from a trial testing ornamental plants that are subjected to a range of treatments during production and home-life. The results of the analysis show how a number of control and noise factors affect the rate of post-production quality decline. Although the model is used to analyse quality data from a trial on ornamental plants, the approach developed is expected to be more generally applicable to a wide range of other complex production systems.     

A variable-neighbourhood search algorithm for finding optimal run orders in the presence of serial correlation

The responses obtained from response surface designs that are run sequentially often exhibit serial correlation or time trends. The order in which the runs of the design are performed then has an impact on the precision of the parameter estimators. This article proposes the use of a variable-neighbourhood search algorithm to compute run orders that guarantee a precise estimation of the effects of the experimental factors. The importance of using good run orders is demonstrated by seeking D-optimal run orders for a central composite design in the presence of an AR(1) autocorrelation pattern.     

Doubly adaptive biased coin designs with heterogeneous responses

Doubly adaptive biased coin design (DBCD) is an important family of response-adaptive randomization procedures for clinical trials. It uses sequentially updated estimation to skew the allocation probability to favor the treatment that has performed better thus far. An important assumption for the DBCD is the homogeneity assumption for the patient responses. However, this assumption may be violated in many sequential experiments. Here we prove the robustness of the DBCD against certain time trends in patient responses. Strong consistency and asymptotic normality of the design are obtained under some widely satisfied conditions. Also, we propose a general weighted likelihood method to reduce the bias caused by the heterogeneity in the inference after a trial. Some numerical studies are also presented to illustrate the finite sample properties of DBCD.     

美国寄宿学院传统对中国本科教育的启示

寄宿学院是美国高等教育的一个重要传统.其始终以本科教育为核心,与研究型大学、社区学院共同支撑着19世纪以来美国高等教育的发展.通过对美国寄宿学院的发展概况、特点及相关案例的分析,可以从管理实践和理论层面探讨美国寄宿学院传统对中国本科教育的启示.     

大学图书馆Web站点导航调研与设计

大学图书馆Web站点导航是充分利用网站资源、正确引导用户为其提供有效信息的最佳工具,是快速查找站内外信息的蜜钥。论文采用网上调查分析与综合的方法,从大学图书馆Web站点四种导航方式入手,对国内外10所不同层次大学图书馆Web站点导航实践进行分析,发现国内大学图书馆Web站点导航存在专业术语不规范、导航元素不齐备、分类存在交迭性、导航菜单布局设计、位置设计不合理等问题,最后针对导航的深度和广度、导航菜单的布局设计等方面提出可操作性的建议。     

Understanding and Using Mediators and Moderators

Mediation and moderation are two theories for refining and understanding a causal relationship. Empirical investigation of mediators and moderators requires an integrated research design rather than the data analyses driven approach often seen in the literature. This paper described the conceptual foundation, research design, data analysis, as well as inferences involved in a mediation and/or moderation investigation in both experimental and non-experimental (i.e., correlational) contexts. The essential distinctions between the investigation of mediators and moderators were summarized and juxtaposed in an example of a causal relationship between test difficulty and test anxiety. In addition, the more elaborate models, moderated mediation and mediated moderation, the use of structural equation models, and the problems with model misspecification were discussed conceptually.

农民工社会养老保险局部推进制度设计研究

建立农民工社会保障将促进我国经济和社会协调互动发展。在分析影响农民工社会养老保险各因素的基础上,设计了符合当前我国农民工社会养老保险局部推进战略的制度模式。该模式建立了自动对农民工分层分类的机制,充分考虑了我国城镇职工基本养老保险的未来改革,在保证政府承担有限责任的基础上保护了农民工的权益并平衡了企业利益。     

Gender differences in labour market integration trajectories of recently arrived migrants in the Netherlands

This study investigates gender differences in recently arrived migrants’ labour market activity and occupational status both shortly after arrival and with increasing length of stay. We examine the role of education, household composition and traditional gender role values by estimating multi-group multilevel models based on three waves of the New Immigrants to the Netherlands Survey. In line with findings regarding gender gaps in labour market behaviour, recent female migrants are less active on labour market than their male counterparts, and we observe a clear motherhood penalty and fatherhood premium on the number of hours worked. Men and women show only marginal differences in their occupational statuses. Changes over time do not differ between men and women, indicating persistent gender inequality in labour market attainment. Moreover, interesting differences between the nationalities were found. Polish migrants show the highest activity levels and lowest occupational status, also when compared to Bulgarians. Spanish migrants hold the highest occupational statuses. Recent Turkish migrants seem to be better integrated and show fewer gender differences than the more established Turkish minority in the Netherlands.     

FIDIC合同条件中工程师的作用及其在中国的发挥

FIDIC合同条件中对工程师授权的宽泛性和工程师作用的充分发挥一直被看做该合同条件的一个特点和长处。文章分析该合同条件中工程师的权利和职责,特别是在工程设计、工程质量和争议解决方面,并且探讨这些作用在中国环境下的发挥。