Robuste Indizes für Projection Pursuit

Zusammenfassung.   Die moderne und hoch komplexe Fertigung, z.B. in der Halbleiterindustrie, erfordert für die dabei anfallenden Messdaten der Anlagen- bzw. Prozessparameter multivariate Analysemethoden. Eine dieser m?glichen Analysemethoden ist Projection Pursuit (PP). Dieses Verfahren ist durch geschickte Wahl des so genannten Projektionsindex in der Lage, verschiedenste Datencharakteristika zu detektieren und diese auf anschauliche Weise zu visualisieren. Bei den Projektionsindizes handelt es sich um Funktionen, die eine Projektion auf unterschiedliche Merkmale hin bewerten und dabei jeder Projektion einen Funktionswert zuweisen. Dieser Funktionswert spiegelt die Aussagekraft der Projektion (in Abh?ngigkeit vom verwendeten Index) wider. Die Auswahl bzw. der Aufbau dieser Indizes ist hierbei von entscheidender Bedeutung. Alle hier vorgestellten Indizes zeichnen sich vor allem durch ihren robusten Charakter gegenüber durch Ausrei?er kontaminierte Daten, wie sie in realen Datenszenarien vorkommen, aus. Die durch Anwendung dieser Indizes gewonnenen Einblicke in die komplexe Struktur der Daten erm?glichen es, hochdimensionale Parameterabweichungen und komplexe Zusammenh?nge innerhalb der Daten zu finden. Eingegangen am 11. Februar 2002 / Angenommen am 14. Mai 2002     

Teaching units as the integrating core of mathematics education

How to integrate mathematics, psychology, pedagogy and practical teaching within the didactics of mathematics in order to get unified specific theories and conceptions of mathematics teaching? This problem—relevant for theoretical and empirical studies in mathematics education as well as for teacher training—is considered in the present paper. The author suggests an approach which is based on teaching units (Unterrichtsbeispiele). Suitable teaching units incorporate mathematical, pedagogical, psychological and practical aspects in a natural way and therefore they are a unique tool for integration.     

Analyzing Whispers: college students’ representation and reproduction of sociocultural discourses about bodies,relationships, and (hetero)sexuality using a mobile application

Previous research about college students’ social media usage emphasizes social media practices, often ignoring the content that students’ post. Increasing knowledge about the language that college students use to describe their intimate relationships can inform student affairs practice. Using a digital ethnographic data collection approach and queer theoretical framework, this paper explores the dominant discourses about race, sexuality, and relationships circulated in a mobile social networking application. This paper used content analysis to describe the meaning of text and images produced by college-aged youth in the US. Through this analysis of social media content, I contend that college students engage in the complex representations and reproductions of sociocultural norms about bodies, sexuality, and relationships and that these representations and reproductions influence campus climate. I develop implications for student affairs administrators.     

Editorial Themenheft: Aktuelle Entwicklungen im Softwaretest

Ohne Zusammenfassung     

The Relationships Between Paranormal Belief, Creationism, Intelligent Design and Evolution at Secondary Schools in Vienna (Austria)

The present study is the first to investigate the relationships between a multiple set of paranormal beliefs and the acceptance of evolution, creationism, and intelligent design, respectively, in Europe. Using a questionnaire, 2,129 students at secondary schools in Vienna (Austria) answered the 26 statements of the Revised Paranormal Belief Scale (R-PBS) and three statements about naturalistic evolution, creationism and intelligent design (ID). The investigated Austrian students showed an average R-PBS score of 82.08, more than 50% of them agreed with naturalistic evolution, 28% with creationism, and more than a third agreed with ID, the latter two closely correlated with each other. Females generally showed higher belief scores in the paranormal, creationism and ID. The agreement with naturalistic evolution correlated negatively with religious belief, but not with other paranormal beliefs, whereas the two non-scientific alternatives to evolution significantly correlated with both traditional and paranormal beliefs. Religious belief showed a significant positive correlation with other paranormal beliefs. All subscales of paranormal belief decreased during the eight grades of secondary school, as did acceptance of creationism and ID. However, the acceptance of naturalistic evolution did not correlate with age or grade. Possible reasons and implications for science education and the biology curriculum at Austrian secondary schools are discussed.     

Human handedness in interactive situations: Negative perceptual frequency effects can be reversed!

Left-handed performers seem to enjoy an advantage in interactive sports. Researchers suggest this is predominantly due to the relative scarcity of left-handers compared with right-handers. Such negative frequency-dependent advantages are likely to appear in inefficient game-play behaviour against left-handed opponents such as reduced ability to correctly anticipate left-handers' action intentions. We used a pre-post retention design to test whether such negative frequency-dependent perceptual effects can be reversed via effective training. In a video-based test, 30 handball novices anticipated the shot outcome of temporally occluded handball penalties thrown by right- and left-handed players. Between the pre- and post-tests, participants underwent a perceptual training programme to improve prediction accuracy, followed by an unfilled retention test one week later. Participants were divided into two hand-specific training groups (i.e. only right- or left-handed shots were presented during training) and a mixed group (i.e. both right- and left-handed shots were presented). Our results support the negative frequency-dependent advantage hypothesis, as hand-specific perceptual training led to side-specific improvement of anticipation skills. Similarly, findings provide experimental evidence to support the contention that negatively frequency-dependent selection mechanisms contributed to the maintenance of the handedness polymorphism.     

Eine Erweiterung der Unified Modeling Language zur Verfolgung von Software-Anforderungen in sicherheitskritischen Systemen

Zusammenfassung.   Softwareentwicklungsprozesse auf Basis von Phasenmodellen verlangen eine Ermittlung der Anforderungen zu Beginn der Entwicklung. Die Anforderungen bilden die Basis für die nachfolgenden T?tigkeiten in der Entwicklung. Daher sind die Verfolgbarkeit der Anforderungen durch die Softwareentwicklung und die überprüfung der korrekten Realisierung der Anforderungen wichtig. Dies gilt insbesondere in sicherheitskritischen Anwendungsbereichen. Einerseits ist die Unified Modeling Language (UML) zur Zeit der Standard im Bereich der objektorientierten Software-Modellierung. Andererseits weist die UML Defizite in Bezug auf die Verfolgbarkeit von Anforderungen auf. Im Folgenden werden mehrere L?sungsm?glichkeiten zur Behebung dieses Problems diskutiert. Die Erweiterung des UML-Meta-Modells um eine Meta-Klasse Requirement wird im Detail vorgestellt. Eingegangen am 22. Februar 2002 / Angenommen am 8. Mai 2002     

Modellbasierte Entwicklung eingebetteter Fahrzeugsoftware bei DaimlerChrysler

Steigende Softwareumf?nge und die damit einhergehende Komplexit?tssteigerung erfordern neue Herangehensweisen an die Entwicklung eingebetteter Fahrzeugsoftware. Als Reaktion auf diese Herausforderungen vollzieht sich seit einigen Jahren ein Paradigmenwechsel von der klassischen Programmentwicklung hin zu modellbasierten Techniken. Der Beitrag gibt einen überblick über den Einsatz modellbasierter Entwicklungstechniken bei DaimlerChrysler und zeigt aktuelle Forschungsschwerpunkte auf. The growing amount of software and attendant rise in complexity demand new approaches to the development of embedded vehicle software. For some years now, a paradigm change from classical program development to model-based techniques has been taking place in reaction to these challenges. This paper provides an overview of the application of model-based development techniques at DaimlerChrysler and presents the main foci of current research.

CR Subject Classification D.2.1,D.2.2,D.2.3,D.2.5,D.2.10,I.6.4,I.6.5     

Retrieval quality vs. effectiveness of specificity-oriented search in XML collections

Content-only queries in hierarchically structured documents should retrieve the most specific document nodes which are exhaustive to the information need. For this problem, we investigate two methods of augmentation, which both yield high retrieval quality. As retrieval effectiveness, we consider the ratio of retrieval quality and response time; thus, fast approximations to the 'correct' retrieval result may yield higher effectiveness. We present a classification scheme for algorithms addressing this issue, and adopt known algorithms from standard document retrieval for XML retrieval. As a new strategy, we propose incremental-interruptible retrieval, which allows for instant presentation of the top ranking documents. We develop a new algorithm implementing this strategy and evaluate the different methods with the INEX collection.