861 resultados para Intra-organizational network resources


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Active Networks can be seen as an evolution of the classical model of packet-switched networks. The traditional and ”passive” network model is based on a static definition of the network node behaviour. Active Networks propose an “active” model where the intermediate nodes (switches and routers) can load and execute user code contained in the data units (packets). Active Networks are a programmable network model, where bandwidth and computation are both considered shared network resources. This approach opens up new interesting research fields. This paper gives a short introduction of Active Networks, discusses the advantages they introduce and presents the research advances in this field.

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The availability of a network strongly depends on the frequency of service outages and the recovery time for each outage. The loss of network resources includes complete or partial failure of hardware and software components, power outages, scheduled maintenance such as software and hardware, operational errors such as configuration errors and acts of nature such as floods, tornadoes and earthquakes. This paper proposes a practical approach to the enhancement of QoS routing by means of providing alternative or repair paths in the event of a breakage of a working path. The proposed scheme guarantees that every Protected Node (PN) is connected to a multi-repair path such that no further failure or breakage of single or double repair paths can cause any simultaneous loss of connectivity between an ingress node and an egress node. Links to be protected in an MPLS network are predefined and an LSP request involves the establishment of a working path. The use of multi-protection paths permits the formation of numerous protection paths allowing greater flexibility. Our analysis will examine several methods including single, double and multi-repair routes and the prioritization of signals along the protected paths to improve the Quality of Service (QoS), throughput, reduce the cost of the protection path placement, delay, congestion and collision.

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This paper proposes a practical approach to the enhancement of Quality of Service (QoS) routing by means of providing alternative or repair paths in the event of a breakage of a working path. The proposed scheme guarantees that every Protected Node (PN) is connected to a multi-repair path such that no further failure or breakage of single or double repair paths can cause any simultaneous loss of connectivity between an ingress node and an egress node. Links to be protected in an MPLS network are predefined and a Label Switched path (LSP) request involves the establishment of a working path. The use of multi-protection paths permits the formation of numerous protection paths allowing greater flexibility. Our analysis examined several methods including single, double and multi-repair routes and the prioritization of signals along the protected paths to improve the Quality of Service (QoS), throughput, reduce the cost of the protection path placement, delay, congestion and collision. Results obtained indicated that creating multi-repair paths and prioritizing packets reduces delay and increases throughput in which case the delays at the ingress/egress LSPs were low compared to when the signals had not been classified. Therefore the proposed scheme provided a means to improve the QoS in path restoration in MPLS using available network resources. Prioritizing the packets in the data plane has revealed that the amount of traffic transmitted using a medium and low priority Label Switch Paths (LSPs) does not have any impact on the explicit rate of the high priority LSP in which case the problem of a knock-on effect is eliminated.

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IoT, crowd sensing and smart cities will be a traffic challenge. New communication paradigms as asynchronous messaging carry and forward, scheduled delivery and temporary storage will be needed to manage network resources dynamically. Since traditional end to end security will require keeping security associations among devices for a long time draining valuable resources, we propose and evaluate the use of proxy re-encryption protocols in these scenarios as a solution for reliable and flexible security.

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Internet protocol TV (IPTV) is predicted to be the key technology winner in the future. Efforts to accelerate the deployment of IPTV centralized model which is combined of VHO, encoders, controller, access network and Home network. Regardless of whether the network is delivering live TV, VOD, or Time-shift TV, all content and network traffic resulting from subscriber requests must traverse the entire network from the super-headend all the way to each subscriber's Set-Top Box (STB).IPTV services require very stringent QoS guarantees When IPTV traffic shares the network resources with other traffic like data and voice, how to ensure their QoS and efficiently utilize the network resources is a key and challenging issue. For QoS measured in the network-centric terms of delay jitter, packet losses and bounds on delay. The main focus of this thesis is on the optimized bandwidth allocation and smooth datatransmission. The proposed traffic model for smooth delivering video service IPTV network with its QoS performance evaluation. According to Maglaris et al [5] First, analyze the coding bit rate of a single video source. Various statistical quantities are derived from bit rate data collected with a conditional replenishment inter frame coding scheme. Two correlated Markov process models (one in discrete time and one incontinuous time) are shown to fit the experimental data and are used to model the input rates of several independent sources into a statistical multiplexer. Preventive control mechanism which is to be include CAC, traffic policing used for traffic control.QoS has been evaluated of common bandwidth scheduler( FIFO) by use fluid models with Markovian queuing method and analysis the result by using simulator andanalytically, Which is measured the performance of the packet loss, overflow and mean waiting time among the network users.

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IPTV is now offered by several operators in Europe, US and Asia using broadcast video over private IP networks that are isolated from Internet. IPTV services rely ontransmission of live (real-time) video and/or stored video. Video on Demand (VoD)and Time-shifted TV are implemented by IP unicast and Broadcast TV (BTV) and Near video on demand are implemented by IP multicast. IPTV services require QoS guarantees and can tolerate no more than 10-6 packet loss probability, 200 ms delay, and 50 ms jitter. Low delay is essential for satisfactory trick mode performance(pause, resume,fast forward) for VoD, and fast channel change time for BTV. Internet Traffic Engineering (TE) is defined in RFC 3272 and involves both capacity management and traffic management. Capacity management includes capacityplanning, routing control, and resource management. Traffic management includes (1)nodal traffic control functions such as traffic conditioning, queue management, scheduling, and (2) other functions that regulate traffic flow through the network orthat arbitrate access to network resources. An IPTV network architecture includes multiple networks (core network, metronetwork, access network and home network) that connects devices (super head-end, video hub office, video serving office, home gateway, set-top box). Each IP router in the core and metro networks implements some queueing and packet scheduling mechanism at the output link controller. Popular schedulers in IP networks include Priority Queueing (PQ), Class-Based Weighted Fair Queueing (CBWFQ), and Low Latency Queueing (LLQ) which combines PQ and CBWFQ.The thesis analyzes several Packet Scheduling algorithms that can optimize the tradeoff between system capacity and end user performance for the traffic classes. Before in the simulator FIFO,PQ,GPS queueing methods were implemented inside. This thesis aims to implement the LLQ scheduler inside the simulator and to evaluate the performance of these packet schedulers. The simulator is provided by ErnstNordström and Simulator was built in Visual C++ 2008 environmentand tested and analyzed in MatLab 7.0 under windows VISTA.

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This thesis work concerns about the Performance evolution of peer to peer networks, where we used different distribution technique’s of peer distribution like Weibull, Lognormal and Pareto distribution process. Then we used a network simulator to evaluate the performance of these three distribution techniques.During the last decade the Internet has expanded into a world-wide network connecting millions of hosts and users and providing services for everyone. Many emerging applications are bandwidth-intensive in their nature; the size of downloaded files including music and videos can be huge, from ten megabits to many gigabits. The efficient use of network resources is thus crucial for the survivability of the Internet. Traffic engineering (TE) covers a range of mechanisms for optimizing operational networks from the traffic perspective. The time scale in traffic engineering varies from the short-term network control to network planning over a longer time period.Here in this thesis work we considered the peer distribution technique in-order to minimise the peer arrival and service process with three different techniques, where we calculated the congestion parameters like blocking time for each peer before entering into the service process, waiting time for a peers while the other peer has been served in the service block and the delay time for each peer. Then calculated the average of each process and graphs have been plotted using Matlab to analyse the results

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Internet protocol TV (IPTV) is predicted to be the key technology winner in the future. Efforts to accelerate the deployment of IPTV centralized model which is combined of VHO, encoders, controller, access network and Home network. Regardless of whether the network is delivering live TV, VOD, or Time-shift TV, all content and network traffic resulting from subscriber requests must traverse the entire network from the super-headend all the way to each subscriber's Set-Top Box (STB). IPTV services require very stringent QoS guarantees When IPTV traffic shares the network resources with other traffic like data and voice, how to ensure their QoS and efficiently utilize the network resources is a key and challenging issue. For QoS measured in the network-centric terms of delay jitter, packet losses and bounds on delay. The main focus of this thesis is on the optimized bandwidth allocation and smooth data transmission. The proposed traffic model for smooth delivering video service IPTV network with its QoS performance evaluation. According to Maglaris et al [5] first, analyze the coding bit rate of a single video source. Various statistical quantities are derived from bit rate data collected with a conditional replenishment inter frame coding scheme. Two correlated Markov process models (one in discrete time and one in continuous time) are shown to fit the experimental data and are used to model the input rates of several independent sources into a statistical multiplexer. Preventive control mechanism which is to be including CAC, traffic policing used for traffic control. QoS has been evaluated of common bandwidth scheduler( FIFO) by use fluid models with Markovian queuing method and analysis the result by using simulator and analytically, Which is measured the performance of the packet loss, overflow and mean waiting time among the network users.

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The advent of the Internet and the World Wide Web has been instrumental in bringing about the growth in the implementation of web-based information systems (WBIS). Such systems are designed with the aim of improving productivity, data accuracy, and the reduction of paperwork and administrative overheads. Moreover, unlike their conventional non-web-based predecessors, the WBIS are commonly aimed at users who are casual and untrained, geographically distributed and non-homogenous. The dissemination of WBIS necessitates additional infrastructure support in the form of a security system, workflow and transaction management, and web administration. WBIS are commonly developed using an evolutionary approach, whereby the version of the application, acquired from the vendor, is first deployed as a pilot, in order to gather feedback from the target users before the evolutionary cycles commence. While a number of web development methodologies have been proposed by existing research, there is a dearth of empirical evidence that elucidates the experiences of project initiators in pursuing the evolution of web services, a process that undoubtedly involves dealing with stakeholder issues. This research project presents a phenomenological investigation of the experiences of project managers with the implementation of web-based employee service systems (ESS), a domain that has witnessed a sharp growth in Australia in recent times. However, the project managers’ rich, multidimensional account of their experiences with the implementation of ESS revealed the social obstacles and fragility of intra-organizational relationships that demanded a cautious and tactful approach. Thus, the study provides a socio-organizational perspective to web projects in contrast to the functionalist paradigm of current web development methodologies. The research also confirms that consideration of the concerns of stakeholders by project managers is crucial to the successive cycles of ESS evolution. Project managers address stakeholder concerns by pursuing actions that are aimed at encouraging ESS usage, but at the same time, such actions can have consequences necessitating subsequent iterations of system enhancement and improvement. Finally, the research also discovered that despite the different socio-political climate prevalent in various organizations, in which ESS are being implemented, the experiences of project managers in dealing with stakeholder concerns can be captured and independently confirmed in terms of their perceived relevance and usefulness in problem-solving within the application domain.

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Anycast in next generation Internet Protocol is a hot topic in the research of computer networks. It has promising potentials and also many challenges, such as architecture, routing, Quality-of-Service, anycast in ad hoc networks, application-layer anycast, etc. In this thesis, we tackle some important topics among them. The thesis at first presents an introduction about anycast, followed by the related work. Then, as our major contributions, a number of challenging issues are addressed in the following chapters. We tackled the anycast routing problem by proposing a requirement based probing algorithm at application layer for anycast routing. Compared with the existing periodical based probing routing algorithm, the proposed routing algorithm improves the performance in terms of delay. We addressed the reliable service problem by the design of a twin server model for the anycast servers, providing a transparent and reliable service for all anycast queries. We addressed the load balance problem of anycast servers by proposing new job deviation strategies, to provide a similar Quality-of-Service to all clients of anycast servers. We applied the mesh routing methodology in the anycast routing in ad hoc networking environment, which provides a reliable routing service and uses much less network resources. We combined the anycast protocol and the multicast protocol to provide a bidirectional service, and applied the service to Web-based database applications, achieving a better query efficiency and data synchronization. Finally, we proposed a new Internet based service, minicast, as the combination of the anycast and multicast protocols. Such a service has potential applications in information retrieval, parallel computing, cache queries, etc. We show that the minicast service consumes less network resources while providing the same services. The last chapter of the thesis presents the conclusions and discusses the future work.

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This folio presents three studies (a dissertation and two electives) which use qualitative case study methodologies to investigate technology adoption from three perspectives. Central to all three studies is the study context of Monash University. The Dissertation explores adoption of web-based learning and teaching approaches from the perspective of teaching academics as they incorporate these to facilitate their students’ learning. The study investigates teaching academics’ reasons for adopting these new technologies, the factors that influenced their adoption decisions, and the challenges they were confronted with, including the contributing factors that impacted on their adoption decisions. The study shows that while contextual factors such as power and politics of the school, department, faculty and the institution impact on adoption, supportive organisational infrastructures and policy frameworks are necessary to encourage adoption, including wider adoption. In turn, on going staff development, adoption of new work practices and being adaptive to changing work environments are key demands made on teaching academics as a result of adopting web-based teaching approaches. Elective 1, a smaller study, leads on from the dissertation and examines the impact of technology adoption on the evolving role of educational designers. The study identifies the educational designers’ role change in assisting teaching academics to move from more conventional forms of teaching to more technology based learner-centred collaborative models. An important aspect of the study is the managers’ perspectives of this role in a university that has adopted a strong flexible learning and technology policy. The findings show that educational designers now work as project managers in larger teams consisting of a wider range of professionals, their expanded role in introducing technology into learning designs, providing staff development in the area, and giving technical help including advice on copyright and intellectual property issues. Elective 2 explores student readiness to adopt these technologies for learning. The study is designed to achieve an understanding of three broad categories of learners from a first year design unit: (1) South East Asian and East Asian students, (2) all other international students, and (3) local Australian students are studied to examine their readiness for modes of learning that are flexible; their approaches to study in a creative discipline area; and their openness to using technology. Findings of the study are discussed under the key themes – dependence on the teacher and classroom environment, flexible learning and working alone, structure, communication and work patterns. The study concludes by discussing the possible cultural attributes that have an impact on the learning. The three studies found that the institution, its people, structures and processes must all adapt, evolve and grow in order to provide effective, engaging, student-centred web-based learning environments. Students in turn must be enabled to manage their study, make use of the technologies and maximise their learning experience. The findings revealed the stage of technology use reached at Monash University at the time of the study through the voices of the teaching academics, educational designers and students.

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A range of factors, both internal and external, is creating changes in teaching and teachers’ professional lives. Information and Communication Technology (ICT) is just one of the major changes impacting on the teaching profession. As teachers face intense pressure to adapt to this tsunami, this study aims to investigate ways in which teachers can be helped. In South Australia, where this study is set, all teachers in Government schools are expected to be "ICT Smart", i.e. able to use appropriate forms of ICT to enhance the teaching and learning environment of their classrooms. From the researcher’s involvement for over a decade in professional development for teachers, and from visits to many schools, it appears that numerous teachers have not reached this standard. The greatest need is in Reception to Year 7 schools where the average age of teachers is nearly 50. Because no state-wide data exists, this study is intended to establish if there is a problem and if there is, to identify specific needs and offer possible solutions. The study is comprised of four parts: Part A, the Introduction gives an overview of the inter-relationships between these parts and the overall Folio. It establishes the setting and provides a rationale for the study and its focus on Professional Development in Information and Communication Technology. Part B, the Elective Research Studies, follows the writer’s involvement in this field since the 1980s. It establishes the theme of "Moving best practice in ICT from the few to the many" which underlies the whole study. Part C, the Dissertation, traces the steps taken to investigate the need for professional development in ICT. This is achieved by analysing and commenting on data collected from a state-wide survey and a series of interviews with leading figures, and by providing a review of the relevant literature and past and existing models of professional development. Part D, Final Comments, provides an overview of the whole Folio and a reflection on the research that has been conducted. The findings are that there is widespread dissatisfaction with existing models and that there is an urgent need for professional development in this area, because nearly 20% of teachers either do not use computers or are considered to be novice users. Another 25% are considered to be below not yet "ICT Smart". Less than 10% of ICT co-ordinators have a formal qualification in the field but more than 85% of them are interested in a Masters program. The study offers solutions in Part B where there is a discussion of a range of strategies to provide on-going professional development for teachers. Chapter 9 provides an outline of a proposed Masters level program and offers suggestions on how it could be best delivered. This program would meet the identified needs of ICT co-ordinators. The study concludes with a series of recommendations and suggestions for further research. The Education Department must address these urgent professional development needs of teachers, particularly those in the more remote country regions. There needs to be a follow-up survey to establish to what extent teachers in South Australia are now "ICT Smart ".

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The main goal of this research was to develop a Blended Learning Model which incorporated traditional learning technologies into e-learning. The model is aimed at assisting students to learn in an environment that contains elements of their preferred learning style whilst still being emerged in the local learning environment.

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This study, which sought to determine the potential of an online community of practice among biology teachers in Botswana, has identified teacher level, school level and systemic influences as shaping the process and outcome of an online intervention into a teacher professional development programme run by the University of Botswana.

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There has been limited evaluation of the effectiveness of psychological interventions for female sexual dysfunction (FSD). Further, none of these studies have evaluated the effectiveness of these interventions delivered over the internet. The current study evaluated an internet-based psychological treatment program for FSD. In total, 39 women (17 in treatment group, 19 in control group) completed the program. The results demonstrated that women who completed treatment reported improved sexual and relationship functioning in comparison to those who received no treatment. The portfolio draws on four case studies from the author's placement experience to demonstrate the role of negative life events, social support and psychological adjustment.