Verteilte Metadatenverwaltung und Anfragebearbeitung für Internet-Datenquellen

Zusammenfassung.   Wir pr?sentieren in dieser Arbeit das ObjectGlobe-System, ein offenes und verteiltes Anfragebearbeitungssystem auf Internet-Datenquellen. ObjectGlobe erweitert die begrenzten F?higkeiten des Internets bezüglich Anfragebearbeitung, indem es einen offenen Marktplatz schafft, in dem eine Vielzahl von Anbietern Rechenzeit, Daten und Anfrageoperatoren bereitstellen. Den Schwerpunkt dieses Beitrags bildet die im Rahmen des ObjectGlobe-Projekts entwickelte Metadatenverwaltung MDV, ein verteiltes Metadaten-Management-System. Es besitzt eine 3-schichtige Architektur und unterstützt Caching und Replikation in der Mittelschicht, so dass Anfragen lokal ausgewertet werden k?nnen. Benutzer spezifizieren die Informationen, die sie ben?tigen und die repliziert werden, mit Hilfe einer besonderen Regelsprache. Um Replikate aktuell zu halten und die Replikation von neuen und relevanten Informationen anzusto?en, verwendet das MDV-System einen neuartigen Publish & Subscribe-Algorithmus. Wir beschreiben diesen Algorithmus im Detail und zeigen, wie er mit Hilfe eines normalen relationalen Datenbanksystems implementiert werden kann. Eingegangen am 19. November 2001 / Angenommen am 30. Juli 2002     

A topography of free kicks in soccer

ABSTRACT

This study investigates the spatial relationship of performance variables for soccer free kicks. In order to suggest ways in which players might optimise their performance, we collected data from free kicks (<35 m to goal line) of two German Bundesliga seasons (2013/14, 2014/15) (n = 1624). In the analysis, we applied the ISO-map approach using colour gradients to visualise the mean values of a variable on a 2D-map of the pitch. Additionally, variograms were used to describe the degree of spatial dependence of the free kick variables. Results show that DENSITY, TYPE OF PLAY, PLAYERS IN WALL, DISTANCE TO WALL and RULE VIOLATION were strongly spatially dependent. Centrality and proximity to the goal increased the variables PLAYERS IN WALL, RULE VIOLATIONS and INTERRUPTION TIME, and the ratio of goals scored increased from 5.9% (central far) to 10.9% (central near). In 70.9% of the shots, players preferred a switched laterality, which did not result in a higher success rate. Furthermore, there was no statistical advantage for the defensive team when DISTANCE TO WALL was below 9.15 m or when there was a RULE VIOLATION. Crosses had a success rate (i.e., first controlled ball contact after the cross) of 20.8%. Played with natural laterality, they were 5% more successful than with switched laterality. Crosses from the right side outside the penalty box were 10% more successful than from the left side. Therefore, it might be worthwhile practising the defence of balls coming from this side.     

Institutional isomorphism,entrepreneurship and effectiveness: the adoption and implementation of quality management in teaching and learning in Germany

This paper presents empirical evidence on the adoption, implementation and the perceived effectiveness of quality management in teaching and learning in German higher education institutions. Theoretically, the article combines two new institutionalist approaches: institutional isomorphism and institutional entrepreneurship. Empirically, the study refers to qualitative interview data and quantitative survey data. The analysis reveals that isomorphism is a leading driver behind the adoption of quality management in German higher education institutions, whereas institutional entrepreneurship plays an important role in quality management implementation. While isomorphism can be regarded as a conclusive reason behind the absence of a perception of quality management’s effectiveness, institutional entrepreneurship may function as a corrective towards the overall negative impact of isomorphic conformity by institutionalizing quality management in a sustainable manner.

     

Ball launch conditions for skilled golfers using drivers of different lengths in an indoor testing facility

The displacement of the golf ball struck by a driving club is affected by several player characteristics and equipment parameters and their interrelationships. Some modelling and simulation studies have shown a relationship between shaft length and clubhead speed, supported by a few experimental studies. The aim of the present study was to examine the relationship between driver length and ball launch conditions in an indoor test facility using a ball launch monitor. Nine males considered to be skilled golfers participated in the study. Four driving clubs of total length 117, 119, 124, and 132 cm were assembled from commercially available components and were used to strike golf shots while initial ball velocity, backspin rate, and launch angles were measured. Statistical analysis identified a significant difference in initial launch speed due to club length, a significant difference between participants, but no difference between the trials for a given golfer. A positive trend was noted between backspin and launch angle for all four clubs, and significant inverse associations between initial launch speed and backspin rate and launch angle. However, the combined launch conditions associated with increasing length were not considered optimal, with uncontrolled swingweight and moment of inertia effects considered to be limiting factors.     

The Sexual Orientation Counselor Competency Scale: Assessing Attitudes,Skills, and Knowledge of Counselors Working With Lesbian,Gay, and Bisexual Clients

This study examined the psychometric properties of the Sexual Orientation Counselor Competency Scale (SOCCS), an instrument that measures the attitudes, skills, and knowledge of counselors who work with lesbian, gay, and bisexual individuals. Internal consistency of the SOCCS was .90, and 1‐week test‐retest reliability was .84. Criterion, concurrent, and divergent validity tests established the SOCCS as a psychometrically sound instrument.     

Learning to solve ill-defined statistics problems: does self-explanation quality mediate the worked example effect?

Instructional Science - Extensive research has established that successful learning from an example is conditional on an important learning activity: self-explanation. Moreover, a model for...