Bayesian discrete latent spatial modeling of crack initiation in orthopaedic hip replacement bone cement

In this paper, we propose a spatial model for the initiation of cracks in the bone cement of hip replacement specimens. The failure of hip replacements can be attributed mainly to damage accumulation, consisting of crack initiation and growth, occurring in the cement mantle that interlocks the hip prosthesis and the femur bone. Since crack initiation is an important factor in determining the lifetime of a replacement, the understanding of the reasons for crack initiation is vital in attempting to prolong the life of the hip replacement. The data consist of crack location coordinates from five laboratory experimental models, together with stress measurements. It is known that stress plays a major role in the initiation of cracks, and it is also known that other unmeasurable factors such as air bubbles (pores) in the cement mantle are also influential. We propose an identity-link spatial Poisson regression model for the counts of cracks in discrete regions of the cement, incorporating both the measured (stress), and through a latent process, any unmeasured factors (possibly pores) that may be influential. All analysis is carried out in a Bayesian framework, allowing for the inclusion of prior information obtained from engineers, and parameter estimation for the model is done via Markov chain Monte Carlo techniques.     

Characteristics of U.S. cities with extreme (high or low) crime rates: Results of discriminant analyses of 1960, 1970, and 1980 data

Why do some cities have higher or lower crime rates than others? In this study we attempt to answer this fundamental question by identifying the theoretically motivated structural covariates which differentiate U.S. cities with extreme high and low crime rates. We apply discriminant function analysis across comprehensive samples of all U.S. cities with populations of greater than 25 000 in the periods 1960, 1970, and 1980 and then posit four question: are empirical findings from regression-based studies of city crime rates replicated in discriminant studies with extreme rates? Are the covariates that predict high or low crime rates unique to specific time periods? Which covariates are better able to discriminate high or low rates for specific crimes? And are specific covariates distinguishable in crime rate changes across time periods? Among our general findings, it appears that those cities with extreme high (low) crime rates tend to be the largest (smallest), most (least) economically deprived, and most (least) socially disintegrated. Associations with these latter two characteristics appear to have grown stronger over the past three census periods. The theoretical importance of these and other findings uncovered here are discussed and interpreted through Wilson's (1987) notion of concentration effects and social isolation which may have transformed inner-city areas in recent years.     

基于思维法则学的群决策方法及其应用

针对群决策中如何科学地收集、集成、分析决策者真实看法的问题,基于西方的思维法则学理论,提出了指示优先级的程式化方法。该方法蕴涵了东方管理中的均衡思想,广泛用于爱尔兰政府及企业的各种项目中。作为该方法的原创者和翻译者合作团队,我们在5年多的合作研究中,探索了有关的理论发展及其中文表述。本文介绍指示优先级的程式化方法的适用情景和应用步骤,与其他方法论进行了比较,给出了应用案例。在应用案例中,对陕西省的5个市县财政局进行了访谈和问卷调查,对西安市财政局的调查数据进行了识别、集成和分析,得到了决策方案及优先级次序。应用结果表明:指示优先级的程式化方法适用于中国情境下的多属性/多准则群决策,能够提供决策依据。     

A hybrid approach to the study of CPFR implementation enablers

Collaborative planning, forecasting and replenishment (CPFR) is one of the most important but also one of the most difficult collaborative strategies in supply chain management. CPFR has been well documented in past research as providing significant benefit to those that implement it well. It has also been noted that CPFR uptake has been significantly lower than initially expected. The main reason for this slow uptake is the general recognition that successful implementation of CPFR is not a trivial task and the fact that it inflicts dramatic changes to the ‘usual’ way of doing business. Based on the premise that CPFR has significant positive potential for supply chain collaboration, the motivation of this paper is to review CPFR enablers and to develop a model which addresses the most significant ones. To complete this task, a hybrid modelling approach integrating fuzzy extended analytical hierarchy process and interpretive structural modelling is proposed. The model developed is based on an identified gap by the automotive sector and embeds expert opinion, from two separate industrial groups in the automotive sector through the use of workshops. Although potential success factors for CPFR implementation can vary across somewhat between differing supply chains, the results maintain wider general applicability due to the many common issues across sectors. The paper highlights the need for decision-makers to be aware of the most influential enablers prior to a CPFR implementation project and to understand the relationships between these enablers.     

Do Tax–Benefit Systems Cause High Replacement Rates? A Decompositional Analysis Using EUROMOD

This paper considers using a cross‐country microsimulation tax–benefit model for Europe, EUROMOD, to simulate the distribution of replacement rates for six European countries, Denmark, France, Germany, Italy, Spain, and the UK. In particular we show the important role of household composition and the presence of other household members' incomes in preserving the standard of living while out of work compared with the impact of the tax–benefit system. Given this strong influence of primary incomes, replacement rates are not necessarily the best indicator of the impact of the tax–benefit system in this respect. We therefore consider in addition an alternative measure, the participation tax rate.     

思维法则学框架下东西方管理理论的比较——探索管理科学中国学派走向世界的道路

思维法则学下的CmCvAwAs系统理论,汲取了哲学和心理学的成果,包含了东方哲学思想,可为东西方管理理论的比较提供一个结构化框架.在CmCvAwAs系统理论框架下,对需要层次理论、系统开发的生命周期理论、质量管理理论、群体发展阶段理论、物理-事理-人理系统理论、东方管理学、和谐管理理论、和合管理理论进行了比较,分析了CmCvAwAs系统理论对于管理研究和管理实践的理论含义,并基于此给出了管理科学中国学派走向世界的一些具体的机遇和挑战.     

A continuous latent spatial model for crack initiation in bone cement

Summary.  Hip replacements rovide a means of achieving a higher quality of life for individuals who have, through aging or injury, accumulated damage to their natural joints. This is a very common operation, with over a million people a year benefiting from the procedure. The replacements themselves fail mainly as a result of the mechanical loosening of the components of the artificial joint due to damage accumulation. This damage accumulation consists of the initiation and growth of cracks in the bone cement which is used to fixate the replacement in the human body. The data come from laboratory experiments that are designed to assess the effectiveness of the bone cement in resisting damage. We examine the properties of the bone cement, with the aim being to estimate the effect that both observable and unobservable spatially varying factors have on causing crack initiation. To do this, an explicit model for the damage process is constructed taking into account the tension and compression at different locations in the specimens. A gamma random field is used to model any latent spatial factors that may be influential in crack initiation. Bayesian inference is carried out for the parameters of this field and related covariates by using Markov chain Monte Carlo techniques.     

Explaining levels of within-group wage inequality in U.S. labor markets

Most research on earnings inequality has focused on the growing gap between workers of different races and at different education, age, and income levels, but a large portion of the increasing inequality has actually occurred within these groups. This article focuses on the extent and sources of "within-group" wage inequality in more than 500 labor markets in the United States in 1990. In addition to documenting that within-group wage inequality across regions varies more widely today than over the past several decades, the analysis reveals that two frequently cited explanations of rising wage inequality over time have little impact on within-group wage inequality when measured at the local labor market level: (1) industrial shifts and (2) increased technology and trade. By contrast, flexible and insecure employment conditions (e.g., unemployment, contingent work, and immigration) are associated strongly with high local levels of within-group wage inequality, especially among women.     

Political Transformation and the Reinvention of the Ulster-Scots Identity and Culture

In the 1990s, Ulster-Scots language and culture was mobilized by some Ulster unionists in Northern Ireland as a badge of their cultural identity. The Ulster-Scots language and culture had its eighteenth century, premodern heyday in the north-eastern counties of the north of Ireland where it expressed distinctiveness from English and Englishness. However, in common with many regional dialects elsewhere in Europe, the processes of modernization signalled the demise of Ulster-Scots. The contemporary reinvention of an Ulster-Scots identity was precipitated by the 1990s political transformation of Northern Ireland. This reinvention has multiple manifestations. It is, variously, a myth of origin, a language and culture, a communal consciousness, a reaction against Irish nationalist cultural assertiveness in Northern Ireland, an embryonic nationalism, and a component part of the British identity. Ultimately, the reinvention of the Ulster-Scots cultural narrative appears designed to offset advances made by Irish nationalists in the assertion of their culture in Northern Ireland. Ulster-Scots has also been reinvented in an attempt to provide the Ulster unionist identity with the cultural booster required to deliver security and continuity to an identity experiencing chronic insecurity and doubt during a period of political transformation. However, the ability of Ulster-Scots to deliver on these aims is questionable.