View-Dependent Extraction of Contours with Distance Transforms for Adaptive Polygonal for adaptive polygonal Mesh-Simplification

During decades Distance Transforms have proven to be useful for many image processing applications, and more recently, they have started to be used in computer graphics environments. The goal of this paper is to propose a new technique based on Distance Transforms for detecting mesh elements which are close to the objects' external contour (from a given point of view), and using this information for weighting the approximation error which will be tolerated during the mesh simplification process. The obtained results are evaluated in two ways: visually and using an objective metric that measures the geometrical difference between two polygonal meshes.

Optimizing the learning potential for the distance learning students

The distance learning programme has made its entrance into nursing education, and many see it as a break with the education’s traditions of teaching in the classroom, in practise rooms and at the patient’s bedside (Chaffin & Maddux 2004). Traditionally, many of the technical skills and personal qualities that nurses must acquire are learned through interaction with others. The distance learning programme has therefore given rise to some new problems and challenges, and this article discusses some of these. Empirically, the article builds on a comparative study of three student nurse classes from two Danish nursing schools, including one based on the distance learning programme. By following both distance learning and traditional nursing students in their clinical training, light is cast upon the differences and similarities that may exist in the clinical skills and competences that the students gain under the two programmes. Theoretically the article builds on Etienne Wengers theory on learning in communities of practice, focusing on the relationship between experience and competence in learning related communities of practice (Wenger 1998;Wenger 2004) . The article contributes with findings that are related to the differences between the programmes and the different types of students that each programme attracts. The article argues that an increased didactic and pedagogical focus upon the field of tension between experience and competence will enable an optimisation of the learning conditions of the distance learning students in their clinical teaching. The article, in conclusion, thus places focus on the questions surrounding teaching design in relation to the distance learning programme.

The impact of new technologies on distance learning students

This is a European Commission Leonardo da Vinci Reference Material project on the impact of new technology on distance learning students. It is known that all the Ministries of Education of the 27 European Union countries pay millions of Euros annually in the provision of educational technology for their schools, colleges and universities. A review of the literature of the impact of technology, however, showed that the research in this field was unacceptably fragile. What research there was focused on the impact of technology on children in American schools. The project set out, therefore, to measure the impact of technology on adult education, lifelong learning and distance education, with a particular focus on adult distance learning.

Calculation of the average travel distance in a low-level picker-to-part system considering any distribution function within the aisles

The estimation of the average travel distance in a low-level picker-to-part order picking system can be done by analytical methods in most cases. Often a uniform distribution of the access frequency over all bin locations is assumed in the storage system. This only applies if the bin location assignment is done randomly. If the access frequency of the articles is considered in the bin location assignment to reduce the average total travel distance of the picker, the access frequency over the bin locations of one aisle can be approximated by an exponential density function or any similar density function. All known calculation methods assume that the average number of orderlines per order is greater than the number of aisles of the storage system. In case of small orders this assumption is often invalid. This paper shows a new approach for calculating the average total travel distance taking into account that the average number of orderlines per order is lower than the total number of aisles in the storage system and the access frequency over the bin locations of an aisle can be approximated by any density function.

Cosine Lobe Based Relighting from Gradient Illumination Photographs

We present an image-based method for relighting a scene by analytically fitting cosine lobes to the reflectance function at each pixel, based on gradient illumination photographs. Realistic relighting results for many materials are obtained using a single per-pixel cosine lobe obtained from just two color photographs: one under uniform white illumination and the other under colored gradient illumination. For materials with wavelength-dependent scattering, a better fit can be obtained using independent cosine lobes for the red, green, and blue channels, obtained from three achromatic gradient illumination conditions instead of the colored gradient condition. We explore two cosine lobe reflectance functions, both of which allow an analytic fit to the gradient conditions. One is non-zero over half the sphere of lighting directions, which works well for diffuse and specular materials, but fails for materials with broader scattering such as fur. The other is non-zero everywhere, which works well for broadly scattering materials and still produces visually plausible results for diffuse and specular materials. We also perform an approximate diffuse/specular separation of the reflectance, and estimate scene geometry from the recovered photometric normals to produce hard shadows cast by the geometry, while still reconstructing the input photographs exactly.

Investigations into Velocity and Distance Perception Based on Different Types of Moving Sound Sources with Respect to Auditory Virtual Environments

The characteristics of moving sound sources have strong implications on the listener's distance perception and the estimation of velocity. Modifications of the typical sound emissions as they are currently occurring due to the tendency towards electromobility have an impact on the pedestrian's safety in road traffic. Thus, investigations of the relevant cues for velocity and distance perception of moving sound sources are not only of interest for the psychoacoustic community, but also for several applications, like e.g. virtual reality, noise pollution and safety aspects of road traffic. This article describes a series of psychoacoustic experiments in this field. Dichotic and diotic stimuli of a set of real-life recordings taken from a passing passenger car and a motorcycle were presented to test subjects who in turn were asked to determine the velocity of the object and its minimal distance from the listener. The results of these psychoacoustic experiments show that the estimated velocity is strongly linked to the object's distance. Furthermore, it could be shown that binaural cues contribute significantly to the perception of velocity. In a further experiment, it was shown that - independently of the type of the vehicle - the main parameter for distance determination is the maximum sound pressure level at the listener's position. The article suggests a system architecture for the adequate consideration of moving sound sources in virtual auditory environments. Virtual environments can thus be used to investigate the influence of new vehicle powertrain concepts and the related sound emissions of these vehicles on the pedestrians' ability to estimate the distance and velocity of moving objects.

Online Distance Education: Towards a Research Agenda

Online Distance Education: Towards a Research Agenda offers a systematic overview of the major issues, trends, and areas of priority in online distance education research. In each chapter, an international expert or team of experts provides an overview of one timely issue in online distance education, summarizing major research on the topic, discussing theoretical insights that guide the research, posing questions and directions for future research, and discussing the implications for distance education practice as a whole. Intended as a primary reference and guide for distance educators, researchers, and policymakers, Online Distance Education addresses aspects of distance education practice that have often been marginalized, including issues of cost and economics, concerns surrounding social justice, cultural bias, the need for faculty professional development, and the management and growth of learner communities. At once soundly empirical and thoughtfully reflective, yet also forward-looking and open to new approaches to online and distance teaching, this text is a solid resource for researchers in a rapidly expanding discipline.

Towards a more effective model for distance education

What is the most effective model for academic distance education, given that drop-out numbers in traditional distance education institutions are too high and the demands from the various stakeholders are changing? In this paper this question is answered from the perspective of the Open University of the Netherlands (OUNL). The OUNL has planned to redesign its educational model from the traditional guided self-study model towards a model of active online learning. In essence this means that education will be less content driven; more focus is put on activating students to engage with real world problems supported by tutors and peers using distance media. The drivers for change, the change process and the resulting redesign of the educational model are presented in this paper.

Distance education in transition

In his most recent publication, Against the Tide: Critics of Digitalisation, Otto Peters brings together some of the most formidable and critical voices and compelling perspectives on the potential hazards of digitalization. The viewpoints presented range from personal, anthropological, and pedagogical to more scientific and technical, and arise from multiple disciplines. Peters has long been a respected scholar in the field of distance education, and while Peters’ earlier work has advocated the affordances of digitalization, this latest book is an abrupt shift to the darker side of digitalization. The assembly of critics Peters has gathered come from around the world and different walks of life: journalists, educators, scientists, philosophers, lawyers, mathematicians, and computer scientists, to name a few. Their one shared bond is a deep-seated belief that digitalization will have a profound and lasting impact on humankind – and not only in positive ways. ...