Der Entwurf strukturierter rollenbasierter Zugriffskontrollmodelle

Zusammenfassung. In diesem Beitrag wird ein formaler Ansatz zur Ableitung von Zugriffsrechten auf der Basis eines formalen Organisationsmodells vorgestellt. Hierzu wird der Ansatz der rollenbasierten Zugriffskontrolle (engl. Role-Based Access Control, kurz RBAC) um die M?glichkeit erweitert, Aufbauorganisationen zu modellieren. Der Vorteil gegenüber rollenbasierten Ans?tzen mit einfachen Rollenhierarchien ist die klare Struktur, die einem Zugriffskontrollmodell durch die Organisationsform aufgepr?gt wird. Des Weiteren k?nnen organisatorische Regelungen, wie z.B. Urlaubsvertretung oder Weisungsbefugnis, direkt im Modell hinterlegt werden. Aufwendig zu pflegende und h?ufig inkonsistente Rollenkataloge werden obsolet. Sicherheitsstrategien mit unpr?zisen Vorgaben lassen sich mittels der vorgestellten Technik der sog. `Kompetenzerweiterung' umsetzen. Das zugrundeliegende Paradigma des vorgestellten Ansatzes unterscheidet sich stark von anderen Ans?tzen mit statischer Autorisation. Nutzer k?nnen sich Zugriffsrechte in fest definierten Grenzen selbstverantwortlich zuteilen, wobei jedoch eine nachtr?gliche Kontrolle stark vereinfacht und damit praktikabel wird. Eingegangen am 22. Februar 2001 / Angenommen am 22. Mai 2001     

Idea generation in biomedical engineering courses using Design Heuristics

ABSTRACT

With increasing demand for improved medical equipment and healthcare, next-generation biomedical engineers need strong design skills. Equipping biomedical engineering students with tools for idea generation and development can increase student design success. Design Heuristics are an ideation tool developed through empirical studies of product designs. While identified in the mechanical engineering space, Design Heuristics may be applicable in biomedical engineering design. In our study, we implemented a Design Heuristics session during upper-level undergraduate and first-year graduate biomedical engineering design courses. We examined the applicability of Design Heuristics within individual and team concept generation contexts. The findings demonstrated that biomedical engineering students were able to use Design Heuristics to generate multiple concepts, and that initial concepts produced using Design Heuristics were carried over into final team design. The results support the applicability of Design Heuristics to student idea generation in biomedical engineering design.     

The logotypes of football clubs as expressions of collective identities: a socio-semiotic approach

This paper focuses on 119 logotypes that are depicted on European football club kits. The football clubs were selected based on their participation in the first two rounds of the UEFA Champions League competitions and in specific in its first two rounds covering a period of time from 1993 to 2010. Our research interest focuses on the significance of ideological loading in terms of the codes occurring in team logos as symbols of collective identities. Our view was, firstly, that logotypes have absorbed and internalized values and stereotypes from the wider social sphere (paradigmatic axis) and, secondly, that there is a common structuring of logos in terms of codes (syntagmatic axis). Our research is based on socio-semiotic methodology, which is not confined to a formalistic approach of texts, but scrutinizes them as an integral part of a material, socio-economic and political context. The analysis led to a series of important data referring to the structuring of team logos as well as to how these logos are related.     

Enhancing self-regulation of practice: the influence of graphing and self-evaluative standards

The purpose of this study was to examine the role of graphing of self-recorded outcomes and self-evaluative standards on the acquisition of a motoric skill with 70 college students. It was postulated that students who were provided with graduated self-evaluative standards would surpass those who were provided with absolute standards or no standards (control) in both motoric skill and in motivational beliefs (i.e., self-efficacy, attributions, and self-satisfaction). Regarding graphing of self-recorded outcomes, it was hypothesized that students who graphed their results visually would show higher dart skill and stronger motivational beliefs than participants who did not graph their results. Support was found for these hypotheses. The implications of findings of this study were discussed for instructors in terms of how the effects of self-directed practice can be enhanced.     

Leg amputation side determines performance in curve sprinting: a case study on a Paralympic medalist

The lower limb kinetics of curve sprinting in amputees are not well described in the literature, particularly with respect to the effect of the side of amputation. This is an issue due to the importance of the knowledge for prosthetic design and classification of athletes. Thus, the aim of this study was to investigate the influence of side of amputation on curve sprinting performance in athletes with a unilateral leg amputation. A three-dimensional motion analysis system (Vicon), four force plates (Kistler) and a modified mathematical human model (ALASKA) were used to compare clockwise and counter clockwise curve sprinting lower limb kinematics and kinetics of a Paralympic medalist with a left-sided knee exarticular amputation. Results reveal that vertical ground reaction force application and total vertical impulse were lower when the affected limb was at the inside of the curve. The unaffected limb showed joint mechanics different to those established for non-amputee athletes and might contribute better to propulsion when being the inside limb. Curve sprinting biomechanics and the ability to attain high radial velocities are directly dependent on the side of amputation relative to the curve direction in a unilateral amputee athlete of highest performance level.     

Teacher perspectives on partnerships on families of children with autism

The success of students with disabilities in school and community largely relies on productive family professional partnerships (FPPs). The Individuals with Disabilities Education Act (IDEA, 2004) recognises the importance of family collaboration to student success by mandating that parents be involved in the Individualised Education Plan (IEP) process as full team members. While several previous studies examined the perspectives of parents of children with disabilities on partnerships with educators, less research exists on teacher perspectives on family professional collaborations. Additionally, there are even fewer studies that focus on teacher perspectives on partnerships with parents of children with autism, a disability category which continues to increase in prevalence. The present study contributes to the literature by examining teacher perspectives on factors that build and hinder positive partnerships with families of children with autism. Researchers surveyed 25 Special Education teachers and conducted additional individual interviews and open-ended questionnaires to examine teachers' first-hand experiences. Findings identified four common themes that educators felt helped and hindered collaborative relationships with families. Study results may lead to the development of specific family professional collaboration strategies that can be implemented and discussed in school districts, teacher trainings, pre-service teacher education programs and family workshops.     

Inclusive pedagogies in digital post-Covid-19 higher education

The Covid-19 pandemic has not only led to medical conundrums and uncharted scientific territories but has also engendered new educational challenges and opportunities that need to be considered in order to reconceptualise, recalibrate and reconfigure higher education in terms of its inclusive foundations and orientations. While current research has highlighted the role of digital teaching methodologies in creating the ‘new normal’ in higher education in the post-Covid-19 era, the ‘new normal’ must be concomitantly envisaged in terms of the role of higher education in fostering more inclusive e-learning spaces. This article discusses the ways in which the tenets of an inclusive pedagogical discourse can be conceptualized and enacted in virtual learning environments in terms of teaching methodologies, learner-centred content delivery and formative assessment implementation. The pedagogical triptych should be underpinned by an inclusive and equity-based ‘cyberculture’ that constitutes a sine qua non element in developing all students' sense of belonging and learning in higher education.     

Unsteady flow phenomena in human undulatory swimming: a numerical approach

The undulatory underwater sequence is one of the most important phases in competitive swimming. An understanding of the recurrent vortex dynamics around the human body and their generation could therefore be used to improve swimming techniques. In order to produce a dynamic model, we applied human joint kinematics to three-dimensional (3D) body scans of a female swimmer. The flow around this dynamic model was then calculated using computational fluid dynamics with the aid of moving 3D meshes. Evaluation of the numerical results delivered by the various motion cycles identified characteristic vortex structures for each of the cycles, which exhibited increasing intensity and drag influence. At maximum thrust, drag forces appear to be 12 times higher than those of a passive gliding swimmer. As far as we know, this is the first disclosure of vortex rings merging into vortex tubes in the wake after vortex recapturing. All unsteady structures were visualized using a modified Q-criterion also incorporated into our methods. At the very least, our approach is likely to be suited to further studies examining swimmers engaging in undulatory swimming during training or competition.     

Developing a pedagogy for teaching self-study research: Lessons learned across the Atlantic

This article reports on a collective self-study from our multiple and unique experiences of teaching self-study research in the Netherlands and the United States. Through the methodology of dialog, we merged what we learned from our individual studies which resulted in six guidelines for a pedagogy for teaching self-study research. Without claiming that the six guidelines have full applicability to all teaching contexts, we offer instead a discussion of the complexities and value of framing a pedagogy of self-study research. This study provides a conceptual, theoretical, and practical base for further studies to build a knowledge base on this topic.