University of Mannheim

About: University of Mannheim is a education organization based out in Mannheim, Germany. It is known for research contribution in the topics: Context (language use) & Politics. The organization has 4448 authors who have published 12918 publications receiving 446557 citations. The organization is also known as: Uni Mannheim & UMA.

COMPASS: A probabilistic indoor positioning system based on 802.11 and digital compasses

Abstract: Positioning systems are one of the key elements required by location-based services. This paper presents the design, implementation and analysis of a positioning system called COMPASS which is based on 802.11-compliant network infrastructure and digital compasses. On the mobile device, COMPASS samples the signal strength values of different access points in its communication range and utilizes the orientation of the user to preselect a subset of the training data. The remaining training data is used by a probabilistic positioning algorithm to determine the position of the user. While prior systems show limited accuracy due to blocking effects caused by the human body, we apply digital compasses to detect the orientations of the users so that we can deal with these blocking effects. After a short period of training our COMPASS system achieves an average error distance of less than 1.65 meters in our experimental environment of 312 square meters.

The Evolution and Transformation of European Governance

Abstract: The European Community (EC) is governed without government and, therefore, it is bound to be governed in a particular way In addition, EC governance is penetrating into the political life of member states and its particular mode of governing may disseminate across national borders These, in a nutshell, are the two hypotheses that will be tested The first is that Europe’s supranational Community functions according to a logic different from that of the representative democracies of its member states Its purpose and institutional architecture are distinctive, promoting a particular mode of governance The second is that the process of ‘Europeanisation,’ that is extending the boundaries of the relevant political space beyond the member states, will contribute to a change of governance at national and sub-national levels Being a member of the EU is concomitant with the interpenetrating of systems of governance; any polity which is part of such a ‘penetrated system’ is bound to change in terms of established patterns of governing

Social Selection in Educational Systems in Europe

Abstract: School systems are typically organized as a series of progressions through which the student population moves. At each successive step only a fraction of the population survives and children of different social origins drop out at different rates. With data from the CASMIN project for nine European nations, this paper studies the similarities and differences between nations in the interplay between the general survival pattern and class-related transition rates. In the nations studied, education is distributed in different ways and with differential results for the social classes. For the cohorts studied, the considerable differences between nations in the unequal distribution of education to the offspring of the various social classes is mainly due to the cross-national differences in the general opportunities of attaining the various levels of education, and to the channelling of the student population through the educational institutions and transitions. They are less significantly due to differences between nations in the class effects on transitions. The pattern of class effects on transitions is highly similar among nations, although for single nations several specific deviations from the common pattern can be observed. It is argued that differences among nations in class effects result from historical, institutional, or political peculiarities of those nations, rather than from macro-sociological properties such as level of industrial development.

Multinomial processing tree models: A review of the literature.

Abstract: Multinomial processing tree (MPT) models have become popular in cognitive psychology in the past two decades. In contrast to general-purpose data analysis techniques, such as log-linear models or other generalized linear models, MPT models are substantively motivated stochastic models for categorical data. They are best described as tools (a) for measuring the cognitive processes that underlie human behavior in various tasks and (b) for testing the psychological assumptions on which these models are based. The present article provides a review of MPT models and their applications in psychology, focusing on recent trends and developments in the past 10 years. Our review is nontechnical in nature and primarily aims at informing readers about the scope and utility of MPT models in different branches of cognitive psychology. In a now classical article, Riefer and Batchelder (1988) proposed a class of substantively motivated stochastic mod- els for categorical behavioral data which was relatively well known in statistical genetics at the time (e.g., Elandt- Johnson, 1971), but had received little attention in psycho- logical research up to the 1980s. These models are now known as multinomial processing tree (MPT) models. About 10 years later, Batchelder and Riefer (1999) already identified no less than 30 published MPT models in the psychological literature, most of which were applied to different agendas in cognitive research. The present article provides an update of Batchelder and Riefer's review and focuses on models and their applications published in the past 10 years. Our review includes 70 MPT models and model variants from more than 20 research areas. In the first section, we will present a brief conceptual outline of MPT models using a simple example to illustrate the basics and main advantages of this approach. Technical details will be omitted almost entirely because they have been described elsewhere (e.g., Batchelder & Riefer, 1999; Hu & Batchelder, 1994). The second section sum- marizes MPT models and their applications in different branches of cognitive psychology, with a special focus on models for various memory paradigms. In the third sec- tion, psychological applications of MPT models outside the realm of cognitive psychology will be briefly summarized. The fourth section describes recent developments, general- izations, and innovations in the statistical methodology of MPT models that might be useful for those interested in applying such models. The fifth and final section of our review provides a sketch of computer programs that are currently available for statistical analyses in the MPT framework, along with a summary of the main advantages of each program.