RTP payload format for H.264/SVC scalable video coding

The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team‘s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC.Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL)and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, including the design criteria, use cases, signaling and payload structure.     

Teaching portfolios in higher education and their effects: An explorative study

Although many authors claim benefits of teaching portfolios for use in higher education settings, there are few empirical studies that investigate these benefits.This article deals with the question of whether teaching portfolios are used in higher education, and if so, which effects they bring about. Furthermore, the attitude of teachers towards the use of teaching portfolios is examined. The study shows that currently not very many teachers are using teaching portfolios. When used, a teaching portfolio is an instrument that can bring about some important positive effects. Respondents report that, due to the use of portfolios, they were stimulated to reflect on their own teaching, to actualise the learning content, to improve their course materials, to search for alternative educational methods, etc. When teachers are using teaching portfolios it is important that, besides any negative effects, they also experience positive effects. If this is not the case, teachers will see the teaching portfolio only as an extra administrative inconvenience.     

Educating the urban poor

The historical evidence is examined to see how low-income students have fared in the urban public schools. Research shows that some schools have been able to raise low-income student achievement. In Rutter's 7-year study, leadership of the principal, high teacher expectations, and rigorous academic programs helped raise achievement. While some results have shown that a majority of low-income students have failed, some immigrant groups, such as Jews, seem to adapt more readily and perform better. The implication is that there may be hope for a substantial improvement in the urban public schools.     

Overcoming institutional barriers to broad-based curricular change

Most large organizations, including universities, are fraught with institutional barriers to change. Their very structures can be impediments to the horizontal communication and cooperation necessary to effect broad-based innovation. U.S. automobile makers, however, are learning to overcome such structural obstacles to facilitate innovation. Can universities employ similar techniques? The recent experience of one regional university suggests important attributes of a successful model to facilitate curricular change.     

On Simulation and the Teaching of Statistics

The use of simulation as an instructional tool can promote a deep conceptual understanding of statistics and lead to misunderstandings. Teachers need to be aware of the misconceptions that can arise as a result of simulation and carefully structure classroom activities so as to derive the benefits of this powerful instructional tool.     

Investigating optimal technique in the presence of motor system noise: application to the double layout somersault dismount on high bar

Minimising joint torque is often used as an optimisation criterion when investigating human movement. Alternatively, an aspect of performance may be chosen to be maximised when investigating sporting movements. The aim of the study was to optimise the technique in the backward giant circle prior to a double layout somersault dismount from the high bar using various criteria to determine which best characterised the technique adopted by a gymnast. Ten recorded gymnast trials were used to determine bar release parameters and the level of noise in the gymnast’s movements. A computer simulation model of a gymnast and bar was used to optimise giant circle technique under three criteria: minimising joint torques, maximising the release window and maximising success in the presence of motor system noise. Local and global optimisations of technique were performed using the three criteria starting from the average technique of the 10 recorded trials. All global optimum solutions diverged from the gymnast’s technique. The local optimum for maximising success in the presence of noise had a success rate comparable with the global optimum (98% vs. 100%, respectively). It is concluded that the gymnast’s technique is characterised by maximising success despite operating with motor system noise.