Digital test assembly of truck parts with the IMMA-tool--an illustrative case

Several digital human modelling (DHM) tools have been developed for simulation and visualisation of human postures and motions. In 2010 the DHM tool IMMA (Intelligently Moving Manikins) was introduced as a DHM tool that uses advanced path planning techniques to generate collision free and biomechanically acceptable motions for digital human models (as well as parts) in complex assembly situations. The aim of the paper is to illustrate how the IPS/IMMA tool is used at Scania CV AB in a digital test assembly process, and to compare the tool with other DHM tools on the market. The illustrated case of using the IMMA tool, here combined with the path planner tool IPS, indicates that the tool is promising. The major strengths of the tool are its user friendly interface, the motion generation algorithms, the batch simulation of manikins and the ergonomics assessment methods that consider time.     

Semiparametric inference for survival models with step process covariates

The authors consider Bayesian methods for fitting three semiparametric survival models, incorporating time‐dependent covariates that are step functions. In particular, these are models due to Cox [Cox ( 1972 ) Journal of the Royal Statistical Society, Series B, 34, 187–208], Prentice & Kalbfleisch and Cox & Oakes [Cox & Oakes ( 1984 ) Analysis of Survival Data, Chapman and Hall, London]. The model due to Prentice & Kalbfleisch [Prentice & Kalbfleisch ( 1979 ) Biometrics, 35, 25–39], which has seen very limited use, is given particular consideration. The prior for the baseline distribution in each model is taken to be a mixture of Polya trees and posterior inference is obtained through standard Markov chain Monte Carlo methods. They demonstrate the implementation and comparison of these three models on the celebrated Stanford heart transplant data and the study of the timing of cerebral edema diagnosis during emergency room treatment of diabetic ketoacidosis in children. An important feature of their overall discussion is the comparison of semi‐parametric families, and ultimate criterion based selection of a family within the context of a given data set. The Canadian Journal of Statistics 37: 60–79; © 2009 Statistical Society of Canada     

The Gendered Division of Housework and Couples' Sexual Relationships: A Reexamination

Although contemporary couples increasingly express preferences for egalitarian unions, previous research has suggested that sexual intimacy decreases when routine housework is shared. Yet this research was conducted on data that are decades old. To update this work, the authors compared data from the 2006 Marital and Relationship Survey (MARS) and Wave 2 of the National Survey of Families and Households (NSFH2), collected in 1992–1994. The results indicated change in the association between housework arrangements and sexual intimacy across surveys. Although egalitarian arrangements were associated with lower sexual frequency compared to conventional arrangements in the NSFH2, no such difference was found in the MARS. In fact, reported sexual frequency increased across surveys among egalitarian couples only. In addition, how housework was arranged mattered more for sexual satisfaction among MARS couples than NSFH2 couples. These changes appear to result from the increasing role of perceived equity as a mechanism linking the division of housework to sex.     

The smell of distance: Wallace Stegner’s definition of western non-fiction

Wallace Stegner has argued that land, scale, and aridness are defining characteristics of both the American West and writings about the West. Stegner’s definition is analyzed using his own works and Mark Twain’s Roughing It.     

Objectivity and Narrative in Contemporary Reporting: A Formal Analysis

Traditionally, Americans have held the ideal that newspapers should transmit knowledge to readers by giving “objective” accounts of official events. This article argues that many news stories have extended objectivity through the use of narrative. Stories attempt to evoke feelings in the reader by drawing on a shared stock of knowledge held by members of society through the use of narrative storytelling techniques rather than attempting to transmit neutral information through the form of objectivity.     

For Bayesian Wannabes,Are Disagreements Not About Information?

Consider two agents who want to be Bayesians with a common prior, but who cannot due to computational limitations. If these agents agree that their estimates are consistent with certain easy-to-compute consistency constraints, then they can agree to disagree about any random variable only if they also agree to disagree, to a similar degree and in a stronger sense, about an average error. Yet average error is a state-independent random variable, and one agent's estimate of it is also agreed to be state-independent. Thus suggests that disagreements are not fundamentally due to differing information about the state of the world.     

Constructing simple theories from propositional inventories

For better or worse, vast amounts of the research in the social sciences is done by researchers working independently of each other. Moreover, until quite recently, most of the data gathered has been of the correlational variety, relating two variables at a time. Consequently, those who try to make theoretical sense out of the vast amount of data often give up this task as hopeless.One way of alleviating this situation is through a propositional inventory: by bringing into one volume a large number of propositions that cover similar grounds. The late 1950s and the 1960s saw an upsurge in such inventories and this trend has continued into the 1970s.¹ Yet even these inventories do not condense and organize the data sufficiently to permit one to develop theories from them. In this paper we shall describe and illustrate a procedure which permits one to construct simple theories from propositional inventories.     

Deadbeat dads or inept states? A comparison of child support enforcement systems.

This article provides information on the effectiveness of state child support enforcement systems. We use individual level data from the Child Support Supplements of the Current Population Surveys (1978-1992) to create an index of state effectiveness that captures success at securing child support awards, setting award levels, and collecting obligations. We identify states that were performing above or below the national average in the late 1980s to early 1990s and states that showed substantial improvement or decline in child support effectiveness during the 1980s. Identifying successful states will help researchers to determine what policies and practices are associated with successful enforcement. These variations in state effectiveness also suggest that low levels of child support are not due to deadbeat dads alone but also to inept states.