Three experiments to support the design of lightweight comfortable vehicle seats

Seats need to be more lightweight for airplanes, cars, busses and even trains to contribute to a better environment and to reduce energy consumption. However, a reduction in comfort due to weight reduction is not preferable, which opens a new area of research: improving comfort with a minimum of material or with lightweight materials and systems. In this paper three experiments are performed to test the effects of light weight seats and parts of a seat on comfort. The first experiment shows that a new developed light weight massage system improves comfort and reduces muscle activity. The second experiment shows that the automatic seat adjustment without motors improves the comfort as well. The third experiment showed that a light weight seat following closely the human body contour is experienced on many aspects in the same way as current more heavy seats. More research and models will be needed in this ergonomic field which needs more attention.     

User acceptance of cooperative maneuver-based driving--a summary of three studies

Modern cars offer drivers support with the help of a number of driver assistance systems. Those systems aim to relieve drivers through assumption of sub parts of the driving task (e.g. in case of an Adaptive Cruise Control by regulation of vehicle speed and time gap to preceding vehicle). Today, systems are controlled and monitored separately which leads to efforts to combine the functionality of all systems in an overlying assistance for drivers. The approach of the University of Technology Darmstadt is called Conduct-by-Wire and can be seen as a cooperative maneuver-based driving paradigm, where the driver gives maneuver command to the systems which are automatically executed. This paper summarizes the results of three studies which investigated the user acceptance of this driving paradigm. Overall, it can be said that the acceptance of the system depends on personal traits of the driver and on the driving situation. Almost all participants are willing to use Conduct-by- Wire for routine tasks such as commuting, which makes the systems interesting for company cars. Still, there remain a number of drivers who are not willing to use such a highly automated system at all.     

Non-formal educator use of evaluation results

Increasing demands for accountability in educational programming have resulted in increasing calls for program evaluation in educational organizations. Many organizations include conducting program evaluations as part of the job responsibilities of program staff. Cooperative Extension is a complex organization offering non-formal educational programs through land grant universities. Many Extension services require non-formal educational program evaluations be conducted by field-based Extension educators. Evaluation research has focused primarily on the efforts of professional, external evaluators. The work of program staff with many responsibilities including program evaluation has received little attention. This study examined how field based Extension educators (i.e. program staff) in four Extension services use the results of evaluations of programs that they have conducted themselves. Four types of evaluation use are measured and explored; instrumental use, conceptual use, persuasive use and process use.Results indicate that there are few programmatic changes as a result of evaluation findings among the non-formal educators surveyed in this study. Extension educators tend to use evaluation results to persuade others about the value of their programs and learn from the evaluation process. Evaluation use is driven by accountability measures with very little program improvement use as measured in this study.Practical implications include delineating accountability and program improvement tasks within complex organizations in order to align evaluation efforts and to improve the results of both. There is some evidence that evaluation capacity building efforts may be increasing instrumental use by educators evaluating their own programs.     

Plan Colombia: illegal drugs,economic development and counterinsurgency – a political economy analysis of Colombia's failed war

This article examines the socioeconomic effects of the illegal drug industry on economic and social development in Colombia. It shows that illegal drugs have fostered violence and have had a negative effect on economic development. This article also shows that the Plan Colombia anti‐drug policy has been an ineffective strategy in terms of decreasing drug production, generating economic development and reducing violence. Since this study includes both a statistical analysis of the effects that violence and illegal drugs have on the economic growth of Colombia, along with an evaluation of the Plan Colombia policy programme, it fills the gap between existing empirical studies of the Colombian illegal drug industry and specific analyses of Plan Colombia.     

A macroeconometric disequilibrium analysis of current and future migration from Eastern Europe into West Germany

This paper attempts to evaluate the impact of current and future immigration flows on major macroeconomic variables of the West German economy. The analysis is based on a macroeconometric disequilibrium model for the West German economy. This model is extended until 1995 and used for several simulation experiments. Special attention is given to the notion that the effects of immigration are regime-specific, i.e., they depend on the type of disequilibrium prevailing on the goods and labor market.We are grateful for helpful comments made by Michael Burda, Gustav Heidbrink, Werner Smolny and three anonymous referees. The usual disclaimer applies.     

A critical review of graphics for subgroup analyses in clinical trials

Subgroup analyses are a routine part of clinical trials to investigate whether treatment effects are homogeneous across the study population. Graphical approaches play a key role in subgroup analyses to visualise effect sizes of subgroups, to aid the identification of groups that respond differentially, and to communicate the results to a wider audience. Many existing approaches do not capture the core information and are prone to lead to a misinterpretation of the subgroup effects. In this work, we critically appraise existing visualisation techniques, propose useful extensions to increase their utility and attempt to develop an effective visualisation approach. We focus on forest plots, UpSet plots, Galbraith plots, subpopulation treatment effect pattern plot, and contour plots, and comment on other approaches whose utility is more limited. We illustrate the methods using data from a prostate cancer study.     

A liberal paradox for judgment aggregation

In the emerging literature on judgment aggregation over logically connected propositions, expert rights or liberal rights have not been investigated yet. A group making collective judgments may assign individual members or subgroups with expert knowledge on, or particularly affected by, certain propositions the right to determine the collective judgment on those propositions. We identify a problem that generalizes Sen’s ‘liberal paradox’. Under plausible conditions, the assignment of rights to two or more individuals or subgroups is inconsistent with the unanimity principle, whereby unanimously accepted propositions are collectively accepted. The inconsistency can be avoided if individual judgments or rights satisfy special conditions. Earlier versions of this paper were presented at the LGS-4 Conference in Caen, June 2005, and at the World Congress of the Econometric Society in London, August 2005. We are grateful for the comments we received at both occasions as well as from anonymous referees. Franz Dietrich acknowledges financial support from the European Commission-DG Research Sixth Framework Programme (CIT-2-CT-2004-506084 / Polarization and Conflict Project). Christian List acknowledges the hospitality of the Social and Political Theory Program, RSSS, Australian National University.     

Niveaudurchagangszeiten zur charakterisierung sequentieller schätzverfahren

Let θ be a parameter of a homogenous additive stochastic process. In order to get an unbiased and efficient estimator for a function h(v) one has often to use sequential procedures. In this paper we consider processes of the socalled exponential class. We study level crossing times, which characterize certain sequential estimations. It is shown that the family of level crossing times for an increasing sequence of levels is also a process of the exponential class. The density function of the one-dimensional probability distributions of this new process is given Examples and applications conclude the paper.     

Sozialstrukturelle Interessenlagen und Parteipräferenz in Deutschland

Based on Allbus data, stability and change of the impact of social structurally defined interests on party preference in Germany is investigated. We use both traditional cleavage indicators like union membership or frequency of church attendance and further social structural characteristics like class identification, occupation or unemployment experience. We apply a two-level model with varying intercepts for the 16 Allbus surveys from 1980 to 2008. Beyond the expected results we observe some deviations from the stable relationship between social structural variables and party preference. (1) The younger generation of active Catholics prefers the Christian Democrats less than the older cohorts and the East German working class leaned towards this party immediately after unification. (2) Union members got alienated from the Social Democrats since 2004 due to reforms of unemployment benefits for people being out of work for a longer period of time with the consequence that Die Linke could profit from this trend in West and East Germany. (3) This left socialist party and its forerunner, the PDS, has always been the preferred party of people with unemployment experience. (4) The Greens and the Liberal Party are enduringly supported by specific social groups, the Greens by the social and cultural service class and the FDP by the self-employed, at least since this latter party ended the social liberal coalition with the SPD in 1982.     

User involvement during information systems development: a comparison of analyst and user perceptions of system acceptance

A sample of 150 users and analysts from multiple organizations and many system projects provided field questionnaire data to test hypotheses about the differences in their perceptions of user involvement (UI) and system acceptance. The Franz and Robey [Franz, C.R., Robey, D., 1986. Organizational context, user involvement, and the usefulness of information systems. Decision Sciences, Vol. 17, No. 3, pp. 329–356.] instrument was used for data collection and factor analyzed, resulting in more focused and specific measures. Analysis of the data showed that users and analysts did not agree on the user's involvement nor did they agree on their perceptions of the acceptability of the system to the user. Relationships of self-ratings of UI with system usage and system acceptance by the user demonstrated high correlations, which were attributed to the narrow focus of the UI and system acceptance measures rather than the original more global measure. Analyst perceptions of UI showed no correlation with a user's perceptions of system acceptance.