Development of a knowledge management system for complex domains

Deutsche Flugsicherung GmbH, the German Air Navigation Service Provider, follows a systematic approach, called HERA, for investigating incidents. The HERA analysis shows a distinctive occurrence of incidents in German air traffic control in which the visual perception of information plays a key role. The reasons can be partially traced back to workstation design, where basic ergonomic rules and principles are not sufficiently followed by the designers in some cases. In cooperation with the Institute of Ergonomics in Darmstadt the DFS investigated possible approaches that may support designers to implement ergonomic systems. None of the currently available tools were found to be able to meet the identified user requirements holistically. Therefore it was suggested to develop an enhanced software tool called Design Process Guide. The name Design Process Guide indicates that this tool exceeds the classic functions of currently available Knowledge Management Systems. It offers "design element" based access, shows processual and content related topics, and shows the implications of certain design decisions. Furthermore, it serves as documentation, detailing why a designer made to a decision under a particular set of conditions.     

Old Voters on New Dimensions: Why Do Voters Vote for Pensioners’ Parties? The Case of the Netherlands

This article analyzes the electoral support of the Dutch pensioners’ party 50Plus. Due to its open electoral system and aging population, the Netherlands is a key case to study pensioners’ parties. Our study shows that this pensioners’ party appeals to voters who are characterized by their age and their dependence on the welfare state as well as their policy positions on new lines of political conflict. In particular, their position on the new economic dimension (which concerns welfare state reform) and the new cultural dimension (which concerns immigration and EU integration) is distinct. Moreover, even when the majority of voters for this new party once supported the larger mainstream parties, they are now dissatisfied with the established politics. With rapidly aging populations across established democracies, this study is not just relevant for those studying pensioners’ parties, but rather gives an important insight into the electoral dynamics and popular support for mainstream politics, the welfare state, and social security.     

Networks and outside options

We introduce and characterize a component efficient value for TU games with a cooperation structure which in contrast to the Myerson (Math Oper Res 2:225–229, 1977) value accounts for outside options. It is based on the idea that the distribution of the worth within a component should be consistent with some connected graph which reflects the outside options of the component’s players.     

An optimization approach applied to the optimal stratification problem

A new optimization algorithm is presented to solve the stratification problem. Assuming the number L of strata and the total sample size n are fixed, we obtain strata boundaries by using an objective function associated with the variance. In this problem, strata boundaries must be determined so that the elements in each stratum are more homogeneous among themselves. To produce more homogeneous strata, this paper proposes a new algorithm that uses the Greedy Randomized Adaptive Search Procedure (GRASP) methodology. Computational results are presented for a set of problems, with the application of the new algorithm and some algorithms from literature.     

Work and mental health: the experience of the Quebec workforce between 1987 and 1998

This study examines the distribution of psychological distress in twelve occupational groups over the decade 1987-1998 in the Quebec workforce. Cross-sectional data from the three phases of the Quebec Health and Social Survey are used with n = 9,450 in 1987, n = 10,947 in 1992 and n = 10,960 in 1998, totalling 31,357 workers aged 15 and over. Occupations are classified according to the Canadian Socio-economic Classification of Occupations. Prevalence estimates for occupational groups are computed and logistic regression analyses are conducted controlling for gender, age and marital status. The results show that the prevalence of workers with psychological distress increased sharply between 1987 and 1992 and declined back in 1998 but still increased compared to 1987. However, only non-qualified white collars, semi-qualified blue collars and male non-qualified blue collars show a significant increment in psychological distress over time. Analysis of the differentials in the prevalence of psychological distress gives greater odds of distress for supervisors, semi-qualified white and blue collar workers compared to upper managers. The odds for occupations are stable over time, gender, age and marital status. The odds of female workers significantly decreased in the three phases. It appears that the restructuring of the work environment and the perturbations in the larger society promoted an increase of psychological distress within definite segments of the workforce. The specific contribution of occupation is limited but supervisors and occupations requiring lower qualifications are more at risk regarding mental health at work.     

Sequential search using question-sets with bounded intersections

The paper is concerned with sequential search on a finite set: an unknown element of the finite set is to be found testing its subsets, and getting the information that the unknown element is or is not an element of the tested subset. The optimum of the strategy lengths is found under the condition that the intersection of any two different test-sets is bounded. This condition is generalized taking the intersection of any m different test-sets instead of two, and the general problem is also solved.     

Treatment and reporting of item-level missing data in social science research

Most quantitative studies in the social sciences suffer from missing data. However, despite the large availability of documents and software to treat such data, it appears that many social scientists do not apply good practices regarding missing data. We analyzed quantitative papers published in 2017 in six top-level social science journals. Item-level missing data was found in at least 69.5% of the papers, but their presence was explicitly reported in only 44.4% of all analyzed papers. Moreover, in the majority of cases, the treatments applied to missing data were incorrect, with many uses of deletion methods that are known to produce biased results and to reduce statistical power. The impact of missing data and of their treatment on results was barely discussed. Results show that social scientists underestimate the impact of missing data on their research and that they should pay more attention to the way such data are treated.     

Health care privatization processes in Europe: Theoretical justifications and empirical classification

This article analyses the health care system reform process in Europe based on the concept of privatization. This notion is understood from two perspectives. First, privatization may concern the health care financing or the provision of health services. Second, privatization can be “imposed” on individuals or be “internalized” and then introduced by individuals (patients and doctors). So we emphasize the diversity that privatization can assume. We classify privatization mechanisms used by different countries and identify which of the perspectives presented are more common in 14 European Union countries since the 1980s. The article shows that even if privatization processes are widespread, they assume different patterns in each country.