Content Delivery

Powerful computers and affordable digital media appliances result in a rapid growth of possibilities in the field of multimedia applications. There has been a significant increase in creation and use of multimedia content. Nowadays everybody can be treated as a potential creator and user of multimedia content. In order to deliver multimedia services to end-users, many parties are integrated and a series of Web services is accessed. A Web service in the composition can become unreachable by a number of circumstances, which requires run-time actions to replace it by another compatible Web service. A Web service can also perform less well than guaranteed, which also requires action in order to fulfill QoS requirements. To answer these requirements, we designed a broker middleware offering dynamic selection and composition of Multimedia Content Delivery services and automatic load balancing of these services over the available application servers. Since users want fast and reliable conn...

Internet was designed for network services without any intention for secure communication. Exponential growth of internet and its users have developed an era of global competition and rivalry. Denial of service attack by multiple nodes is capable of disturbing the services of rival servers. The attack can be for multiple reasons e. g. extortion or to beat the rivals. Peer

Objective: To compare the effects of active and didactic teaching strategies on learning- and process-oriented outcomes. Design: Controlled trial. Setting: After-hours residents' teaching session. Participants: Family and Community Medicine, Internal Medicine, and Pediatrics residents at two academic medical institutions. Interventions: We randomly assigned residents to two groups. One group received a didactic lecture on effective use of diagnostic tests; during this session, the teacher spent a full hour delivering content. The other group received the same content in a session structured to foster resident-to-resident interactions. In the latter session, the teacher spent only 30 minutes directly delivering content to residents. Measures and Main Results: We measured residents' knowledge about and attitudes toward the session content before, immediately after, and one month after each session. We measured residents' perceptions of engagement and session value immediately after each session. We employed blinded observers who used a structured instrument to observe residents' activities during each session. Both teaching methods led to improvements in residents' scores on both knowledge and attitude assessments. The amount of improvement was not statistically different between groups. Residents in the active learning session perceived themselves, and were observed to be, more engaged with the session content and each other than residents in the didactic session. Residents in the didactic session perceived greater educational value from the session compared to residents in the active session. Conclusions: We reduced the amount of time spent in teacher-driven content delivery by 50 percent and covered the same amount of content with no detrimental effects on knowledge acquisition or attitude enhancement. Teaching strategies that foster learner-to-learner interactions will lead to more active engagement among learners, however, these learners may value the session less. Further research is needed to explore learner perceptions of the teaching process and other outcomes of active learning in medical education.

At the University of the South Pacific, video broadcast courses, which integrate face-to-face and distance teaching, are proving useful as a means of scaffolding the transition of lecturers from a conventional teaching learning environment towards new ways of teaching that emphasise interaction rather than content delivery. By providing ample support in a professional environment that uses technology to both replicate and supplement the traditional teaching roles, lecturers are allowed a "safe zone" in which to generate new skills while maintaining lecturer comfort.

viii CHAPTER ONE: INTRODUCTION 1 Overview 1 Theoretical Framework 3 Constructivism 3 Sociocultural Theory 4 Interaction and Computer-Mediated Communication 5 Community of Inquiry (CoI) 6 Statement of the Problem 10 Purpose 18 Research Questions 18 Significance of the Study 19 Delimitations and Limitations 21 Delimitations 21 Limitations 22 Operational Definitions of Terms 23 CHAPTER TWO: LITERATURE REVIEW 26 Overview 26 The Theoretical Framework 27 Social Learning and Sociocultural Theory 27 Sociocultural Theory 28 Sociocultural Theory and Distance Education 33 Community 36 Online Learning Community 40 Community of Inquiry (CoI) 43 Social Presence 44 Cognitive Presence 47 Teaching Presence 52 Design and Organization 53 Facilitating Discourse 54 Direct Instruction 56 Distance Education 58 ii History of Distance Education 59 Distance Education for Teacher Education 71 Distance Education and Second Language Teacher Education 76 Interaction (CMC) as a Core Element in Distance Education ...

The Internet is facing a significant evolution from being a delivery network for static content to an efficient platform for multimedia content delivery. Well-known examples of applications driving this evolution are YouTube Video on Demand, Skype Audio/Video conference, IPTV and P2P video distribution. While YouTube streams videos using the Transmission Control Protocol (TCP), time-sensitive applications, such as Skype Audio/Video conference,

- Encryption algorithms play a main role in wireless network security systems. However, those algorithms consume a significant amount of computing resources such as CPU time, and packet size. In an attempt to remedy the wireless network security issue, a novel ...

The performance of a distributed system is affected by the various functions of its components. The interaction between components such as network nodes, computer systems and system programs is examined with special interest accorded to its effect on system reliability. At affordable time and space costs, the analytic hierarchy process (AHP) is used to determine how the reliability of a distributed system may be controlled by appropriately assigning weights to its components. Illustrative case studies, that display the system structure, the assignment of weights and the AHP handling are presented.

nformats and standards. The predominant formatcurrently addressing this issue is the eXtensibleMarkup Language (XML). It supports, for instance,web site presentation, wireless access, and voice activatedaccess for mobile and Internet users alike.Examples of information services include userprole-based content delivery, subscription-based notication, and targeted advertisement distribution tonetwork participants. In wireless networks, even thelocation of a user can be exploited when...

This paper presents a case study of the implementation of a flexible learner-centred programme of study which blends face-to-face and online learning. The programme was developed to be flexible in terms of content and study strategies, whilst remaining within more rigid organisational structures and processes. This paper outlines the programme and presents the model developed for flexible content delivery. The programme has been delivered simultaneously by five tutors to six groups of learners. Tutors drew on varying personal experiences of flexible and online learning and this paper also presents the results of an investigation to explore their experiences of facilitation. The findings provide a unique insight into the implications of such a programme for educators. Data were gathered using methods to promote and structure reflections on practice. Issues of relevance for others considering the development of flexible learner-centred programmes of study are presented.

The democratization of education has brought forth an unprecedented demand for education by the masses, especially at the tertiary level. However, the availability of education is hampered by limited resources to provide pervasive and effective teacher–student interaction, changing lifestyle patterns, changing expectations of the students, and the problems associated with the great urban–rural divide and nonuniform access. The problem of availability of education is compounded by the tide of globalization and the Internet that demands not only high efficiency but also competitive delivery of services and goods in all sectors of our economy, including education. Education is not immune to these current trends. It is imperative that education institutions rise up to the challenge in meeting the demand of a more discerning, discriminating, mobile, and selective student population. It is imperative that education institutions reconsider the necessary ingredients to make learning effective, relevant, and fun for the students. Our company, Kolej Damansara Utama (KDU), has embarked on an education experiment begun almost 3 years ago to implement a student-centered, teacher-facilitated, Information and Communications Technology (ICT)-enabled and knowledge-based initiative. The goal of this experiment has been to create an active learning environment, and to promote learning for our students. The knowledge ecosystem, comprising students, teachers, administrators, parents, partner institutions, employers, and the community at large, forms the KDU e-Community Network (KCN). The KCN enables passive, interactive, collaborative, and constructive learning to take place as long as the stakeholder has a connection to the Internet.

Providing authentication mechanisms for IP-Multicast streams is paramount for the development of large scale commercial multicast content delivery applications. This need is particularly strong for the delivery of real time content, such as live video/audio news events or financial stock quote distribution. However, this turns out to be a quite challenging problem for many reasons. First, the authentication of the multicast data must be verifiable by a potentially very large number of untrusted recipients. Second, since multicast communication protocols are almost always best effort, the authentication mechanisms needs to authenticate received content despite the potential loss of some packets. Finally, the authentication mechanism needs to be efficient enough to cope with real time data and should have a small communication overhead. We propose a new multicast authentication scheme designed to authenticate real time multicast packet streams with a potentially unlimited number of re...