A generalised cost-aware caching scheme for caching continuous media objects in best-effort network environments

In this paper, we investigate the potential of caching to improve QoS in the context of continuous media applications over wired best-effort networks. We propose the use of a flexible caching scheme, called GD-Multi in caching continuous media (CM) objects. An important novel feature of our scheme is the provision of user or system administrator inputs in determining the cost function. Based on the proposed flexible cost function, Multi, an improvised Greedy Dual (GD) replacement algorithm called GD-multi (GDM) has been developed for layered multi-resolution multimedia streams. The proposed Multi function takes receiver feedback into account. We investigate the influence of parameters such as loss rate, jitter, delay and area in determining a proxy’s cache contents so as to enhance QoS perceived by clients. Simulation studies show improvement in QoS perceived at the clients in accordance to supplied optimisation metrics. From an implementation perspective, signalling requirements for carrying QoS feedback are minimal and fully compatible with existing RTSP-based Internet applications.

Agents in adversarial domains - modelling environments in parallel

We present a model of an environment to evaluate the behavior of an agent trying to hide from a pursuer is presented. The model computes the direction and the amount of protection provided by the environment. The computational complexity of this problem is improved by using a parallel implementation of this algorithm.

Are children's perceptions of neighbourhood social environments associated with their walking and physical activity?

This study aimed to examine cross-sectional associations between neighbourhood social environmental factors and physical activity (PA) among Australian primary school children. Baseline data from a large-scale trial among 957 children (48% boys) aged 9–12 years were utilised. Children self-reported their perceptions of the neighbourhood social environment including social networks (e.g. there are lots of other children around to play with), and social capital (e.g. there are lots of people in my area I could go to if I need help). Children also self-reported their weekly walking frequency and PA from which average daily moderate to vigorous PA (MVPA) was calculated. Linear regression analyses examined these associations. Boys performed 17 min/day more MVPA than girls (p < 0.01), and girls performed one extra trip/week than boys (p < 0.001). Children’s perceptions of social capital (p < 0.0001) and social networks (p < 0.01) were both positively associated with MVPA and social capital was positively associated with walking frequency (p < 0.05). These associations were not moderated by the child’s sex. These findings suggest that children who had positive perceptions of neighbourhood social capital and social networks in the neighbourhood, tended to be more physically active. Longitudinal and experimental studies are required to further test the influence of these factors among children.

The social network virtual design studio : integrated design learning using blended learning environments

Online communications, multimedia, mobile computing and face-to-face learning create blended learning environments to which some Virtual Design Studios (VDS) have reacted to. Social Networks (SN), as instruments for communication, have provided a potentially fruitful operative base for VDS. These technologies transfer communication, leadership, democratic interaction, teamwork, social engagement and responsibility away from the design tutors to the participants. The implementation of Social Network VDS (SNVDS) moved the VDS beyond its conventional realm and enabled students to develop architectural design that is embedded into a community of learners and expertise both online and offline. Problem-based learning (PBL) becomes an iterative and reflexive process facilitating deep learning. The paper discusses details of the SNVDS, its pedagogical implications to PBL, and presents how the SNVDS is successful in enabling architectural students to collaborate and communicate design proposals that integrate a variety of skills, deep learning, knowledge and construction with a rich learning experience.

E-Simulations for educating the professions in blended learning environments

This chapter introduces digital, role-based simulations as an emerging and powerful educational approach for the professions and for broader workforce development purposes. It is acknowledged that simulations used for education, professional development, and training, have a long history of development and use. The focus is on digital simulations (e-simulations) situated in blended learning environments and the improved affordances of the newer digital media used via the web to enhance the value of their contribution to learning and teaching in professional and vocationally-oriented fields. This is an area which has received less attention in the whole “e-learning” literature compared with the voluminous body of knowledge and practice on computer-mediated communication, online community building, social networking, and various forms of online (usually automated) assessment. A framework of blended e-simulation design is outlined. The chapter concludes by examining what the future might hold for simulations in further and higher education, and ongoing work-based learning.