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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Estudo de desfecho e manuten??o dos efeitos de uma interven??o baseada na terapia comportamental dial?tica para pessoas com obesidade

Souza, Lucas Andr? Schuster de 08 March 2018 (has links)
Submitted by PPG Psicologia (psicologia-pg@pucrs.br) on 2018-05-17T18:50:07Z No. of bitstreams: 1 LUCAS_ANDRE_SCHUSTER_DE_SOUZA_DIS.pdf: 2165020 bytes, checksum: 83c14e87e569f3c0b94891c827f07ed3 (MD5) / Rejected by Caroline Xavier (caroline.xavier@pucrs.br), reason: Devolvido devido ao t?tulo da folha de rosto (p?gina 2) estar diferente do t?tulo da capa, ficha catalogr?fica e publica??o depositada. on 2018-05-30T17:58:52Z (GMT) / Submitted by PPG Psicologia (psicologia-pg@pucrs.br) on 2018-06-13T13:42:00Z No. of bitstreams: 1 LUCAS_ANDRE_SCHUSTER_DE_SOUZA_DIS.pdf: 2261551 bytes, checksum: 6d2ae6206b912e63a5477cc83923cef8 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-06-25T11:34:35Z (GMT) No. of bitstreams: 1 LUCAS_ANDRE_SCHUSTER_DE_SOUZA_DIS.pdf: 2261551 bytes, checksum: 6d2ae6206b912e63a5477cc83923cef8 (MD5) / Made available in DSpace on 2018-06-25T11:54:40Z (GMT). No. of bitstreams: 1 LUCAS_ANDRE_SCHUSTER_DE_SOUZA_DIS.pdf: 2261551 bytes, checksum: 6d2ae6206b912e63a5477cc83923cef8 (MD5) Previous issue date: 2018-03-08 / Introduction: Obesity is a complex and multifactorial condition that represents a risk factor for several other health problems and reductions in quality of life. The high prevalence and growing incidence of obesity in the world makes it necessary to identify the predisposing factors and effective intervention strategies for its treatment. One of the most important aspects in the treatment of obesity is the promotion of more adaptive eating behaviors and the reduction of problematic eating behaviors. It is currently recognized that emotional regulation is an important element in the etiological equation and maintenance of problematic eating behaviors in obesity and in some eating disorders related to obesity, especially binge eating. Dialectical Behavioral Therapy (DBT) is a behavioral therapeutic approach whose effectiveness has been demonstrated for a wide range of psychopathological conditions in which difficulties with emotional regulation are present. Although there are already several studies demonstrating DBT's efficacy in the context of eating disorders and obesity, in Brazil, research with DBT is still scarce and there are no empirical studies to date about its application to eating disorders. Considering this scenario, two studies were proposed to identify the effectiveness and maintenance of the effects of a group intervention based on the training of TCD Skills for obese people. Goals: To verify the maintenance of effects on problematic and adaptive eating behaviors after a group intervention based on Dialectic Behavioral Therapy for obese people, and to explore relevant aspects of the participants' experience with the intervention. Method: sequential quantitative and qualitative design, using self-report measures and semi-directed interviews. On the quantitative stage, self-report measures of problematic eating behaviors (Binge Eating Scale - BES, Emotional Eating Scale - EES) and adaptive (Mindful Eating Eating Questionnaire - MEQ, Intuitive Eating Scale 2 - IES-2) were used. An intention-to-treat analysis (n = 121) was used with all participants who were assigned for the intervention. Measures were taken at pretest, post-test and 3 and 8 months follow-up. Descriptive analyzes and hierarchical linear modeling were used to verify the effectiveness and stability of the effects of the intervention. In the qualitative phase, semi-directed interviews were conducted with 3 participants who concluded the intervention, focusing on the experience with the intervention, perceived effects, 31 facilitators and difficulties with the participation and implementation of the strategies developed in the treatment. The interviews were analyzed by four researchers, using inductive thematic analysis. Results: There was a significant reduction in problematic eating behaviors after the intervention, with stable results at the three-month follow-up and slight return towards baseline at 8-month follow-up. As for adaptive eating behavior, there was improvement after the intervention, which was maintained at three months follow-up and tended to return to baseline at 8 months follow-up. Analysis of the interviews revealed that participants identified improvements in various aspects of their life after the intervention, especially in interpersonal functioning and in the ability to regulate their own behavior. They point the identification with other group members and the presence of a supportive family and social environment as facilitators of participation in the intervention. Experiences of anxiety and aversive emotions during the group and difficulty in maintaining skills practice outside the sessions were pointed out as obstacles to the effectiveness of the intervention. Discussion: Quantitative results are consistent with other literature findings on DBT interventions in the context of eating disorders and demonstrate that a brief intervention based on DBT and adapted to the Brazilian context may be effective in reducing problematic eating behaviors and promoting more adaptive behaviors in the short and medium term for obese people, however they are not conclusive as to the maintenance of these changes for 8 months or longer. Data from the qualitative study replicated in part other findings in the literature on DBT for people with emotional dysregulation and borderline personality disorder, stressing the importance that clinicians be attentive to aversive emotional experiences during the group and provide support as well as identify opportunities for application of the skills during the group sessions. In addition, the perception of improvement in interpersonal relationships reflects the importance of the interpersonal dimension in obesity and binge eating, highlighting the strong relationship between interpersonal aspects and emotional responses to which maladaptive coping strategies such as overeating may follow. / Introdu??o: A obesidade ? uma condi??o complexa e multifatorial que representa um fator de risco para diversos outros problemas de sa?de e preju?zos ? qualidade de vida. A elevada preval?ncia e crescimento da quantidade de casos de obesidade no mundo, torna necess?rio que se identifiquem os fatores predisponentes e estrat?gias de interven??o eficazes para seu tratamento. Um dos aspectos mais importantes no tratamento da obesidade consiste na promo??o de comportamentos alimentares mais adaptativos e redu??o dos comportamentos alimentares problem?ticos. Reconhece-se atualmente que a regula??o emocional ? um elemento de grande import?ncia na equa??o etiol?gica e na manuten??o dos comportamentos alimentares problem?ticos na obesidade e em alguns transtornos alimentares correlatos da obesidade, em especial a compuls?o alimentar. A Terapia Comportamental Dial?tica (TCD) ? uma abordagem terap?utica de base comportamental cuja efic?cia vem sendo demonstrada para uma ampla gama de condi??es psicopatol?gicas nas quais est?o presentes dificuldades com a regula??o emocional. Apesar de j? haver diversos estudos demonstrando efic?cia da TCD no contexto dos transtornos alimentares e da obesidade, no Brasil, ainda ? escassa a investiga??o com aplica??es da TCD, e inexistente no caso de estudos emp?ricos sobre sua aplica??o a dist?rbios relacionados ao comportamento alimentar. Em face de tal cen?rio, prop?s-se a realiza??o de dois estudos com objetivo de identificar a efetividade e manuten??o dos efeitos de uma interven??o em grupo baseada no treinamento de Habilidades da TCD para pessoas obesas. Objetivos: verificar manuten??o dos efeitos sobre comportamentos alimentares problem?ticos e adaptativos ap?s uma interven??o em grupo baseada na Terapia Comportamental Dial?tica para pessoas obesas, e explorar aspectos relevantes da experi?ncia dos participantes com a interven??o. M?todo: desenho sequencial quantitativo e qualitativo, utilizando medidas de autorrelato e entrevista semidirigida. Na etapa quantitativa, utilizaram-se medidas de autorrelato de comportamentos alimentares problem?ticos (Escala de Compuls?o Alimentar Peri?dica - ECAP; Emotional Eating Scale - EES) e adaptativos (Mindful Eating Questionnaire - MEQ; Intuitive Eating Scale 2 - IES-2). Utilizou-se uma an?lise intention-to-treat (n=121) com participantes 28 selecionados para a interven??o. Foram realizadas medidas de pr?-teste, p?s-teste e seguimento de 3 e de 8 meses ap?s a interven??o. An?lises descritivas e modelagem linear hier?rquica foram utilizadas para verificar a efetividade e estabilidade dos efeitos da interven??o. Na fase qualitativa, entrevistas semidirigidas foram conduzidas com 3 participantes que conclu?ram a interven??o, enfocando a experi?ncia com a interven??o, efeitos percebidos, facilitadores e dificuldades com a participa??o e implementa??o das estrat?gias desenvolvidas no tratamento. As entrevistas foram analisadas por quatro pesquisadores, utilizando o procedimento de an?lise tem?tica indutiva. Resultados: verificou-se uma redu??o significativa nos comportamentos alimentares problem?ticos logo ap?s a interven??o, com resultados est?veis no seguimento de tr?s meses e levemente elevados no seguimento de 8 meses. Quanto ao comportamento alimentar adaptativo, houve melhora logo ap?s a interven??o, com resultados tamb?m est?veis aos tr?s meses de seguimento e tendendo a retornar aos valores iniciais aos 8 meses de seguimento. As entrevistas revelaram que os participantes identificaram melhoras em diversos aspectos de sua vida ap?s a interven??o, especialmente no funcionamento interpessoal e na capacidade de regular o pr?prio comportamento. Apontam a identifica??o com outros membros do grupo e a presen?a de um ambiente familiar e social suportivo como facilitadores da participa??o na interven??o. Experi?ncias de ansiedade e emo??es aversivas durante o grupo e dificuldade de manter a pr?tica das habilidades fora das sess?es foram apontadas como obst?culos para a efetividade da interven??o. Discuss?o: os resultados quantitativos s?o coerentes com outros achados da literatura sobre interven??es de TCD no contexto de dist?rbios da alimenta??o, e demonstram que uma interven??o breve baseada na TCD e adaptada ao contexto brasileiro pode ser efetiva para reduzir comportamentos alimentares problem?ticos e promover comportamentos mais adaptativos em curto e m?dio prazo, no entanto n?o s?o conclusivos quanto ? manuten??o em prazos superiores a 8 meses. Os dados do estudo qualitativo replicaram em parte outros achados da literatura sobre a TCD para pessoas com desregula??o emocional e transtorno limite de personalidade, ressaltando a import?ncia de que os cl?nicos estejam atentos ?s experi?ncias emocionais aversivas durante o grupo, oferecendo suporte e identificando oportunidades de aplica??o das habilidades treinadas durante o o pr?prio grupo. 29 Ademais, a percep??o de melhora nas rela??es interpessoais reflete a import?ncia da dimens?o interpessoal na problem?tica da obesidade e da compuls?o alimentar, dando realce ? forte rela??o entre aspectos interpessoais e respostas emocionais ?s quais podem se seguir estrat?gias maladaptativas de enfrentamento como a sobreingesta de alimentos.
42

Network architecture in a large-scale fully interactive VOD system based on hybrid multicast-unicast streaming.

January 2001 (has links)
Chan Kwun-chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 71-73). / Abstracts in English and Chinese. / 摘要 --- p.II / ABSTRACT --- p.III / ACKNOWLEDGEMENT --- p.V / TABLE OF CONTENTS --- p.VI / LIST OF FIGURES --- p.X / LIST OF SYMBOLS --- p.XII / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Contributions --- p.3 / Chapter 1.2 --- Organization of the Thesis --- p.4 / Chapter 1.3 --- Publications --- p.5 / Chapter 2. --- RELATED WORKS --- p.6 / Chapter 2.1 --- Previous VOD System --- p.7 / Chapter 2.1.1 --- Service Model --- p.7 / Chapter 2.1.1.1 --- Unicast VOD --- p.7 / Chapter 2.1.1.2 --- Multicast VOD --- p.8 / Chapter 2.1.2 --- Architecture --- p.9 / Chapter 2.1.2.1 --- Centralized Architecture --- p.9 / Chapter 2.1.2.2 --- Distributed Architecture --- p.10 / Chapter 2.1.3 --- Interactive Function --- p.11 / Chapter 2.1.3.1 --- Limited Interactive Function --- p.11 / Chapter 2.1.3.2 --- Unlimited Interactive Function --- p.11 / Chapter 2.1.4 --- Split and Merge Operation --- p.12 / Chapter 2.1.4.1 --- SAM Scheme (Split and Merge) --- p.12 / Chapter 2.1.4.2 --- SRMDRU Scheme (Single Rate Multicast Double Rate Unicast) --- p.14 / Chapter 2.2 --- Previous Caching Algorithm --- p.15 / Chapter 2.2.1 --- LFU (Least Frequently Used) --- p.15 / Chapter 2.2.2 --- LRU (Least Recently Used) --- p.15 / Chapter 2.2.3 --- Media Stream Caching --- p.15 / Chapter 3. --- DESIGN OFA NOVEL VOD SYSTEM --- p.17 / Chapter 3.1 --- System Architecture --- p.18 / Chapter 3.1.1 --- Multicast Video Server Cluster (MVSC) --- p.19 / Chapter 3.1.2 --- Unicast Video Server Cluster (UVSC) --- p.20 / Chapter 3.1.3 --- Multicast Backbone Network (MBN) --- p.20 / Chapter 3.1.4 --- Local Distribution Network (LDN) --- p.21 / Chapter 3.1.5 --- Distributed Interactive Server (DIS) --- p.21 / Chapter 3.1.6 --- Distributed Proxy Server (DPS) --- p.22 / Chapter 3.1.7 --- Client Station (CS) --- p.22 / Chapter 3.2 --- Batched Multicast Transmission --- p.24 / Chapter 3.3 --- Split and Merge Operation --- p.26 / Chapter 3.4 --- Interactive Function --- p.31 / Chapter 3.4.1 --- Pause --- p.31 / Chapter 3.4.2 --- Slow Motion --- p.35 / Chapter 3.4.3 --- Various Speed Fast Forward / Fast Rewind (FF/REW) --- p.37 / Chapter 3.4.4 --- Jump Forward/Jump Backward (JF/JB) --- p.42 / Chapter 3.5 --- Performance Analysis --- p.46 / Chapter 3.5.1 --- Model --- p.46 / Chapter 3.5.2 --- System Parameters --- p.49 / Chapter 3.5.3 --- Results --- p.49 / Chapter 4. --- DESIGN OF A VIDEO PROXY SYSTEM --- p.57 / Chapter 4.1 --- Video Proxy System --- p.58 / Chapter 4.1.1 --- Priority Function --- p.59 / Chapter 4.1.2 --- Two-Stage Replacement Policy --- p.60 / Chapter 4.1.3 --- Caching Policy --- p.61 / Chapter 4.2 --- Performance Evaluation --- p.63 / Chapter 4.2.1 --- Simulation Environment --- p.63 / Chapter 4.2.2 --- Performance Metric --- p.64 / Chapter 4.2.3 --- Results --- p.64 / Chapter 5. --- CONCLUSION --- p.69 / BIBLIOGRAPHY --- p.71
43

DINA: a hybrid multicast-unicast fully interactive video-on-demand system.

January 2001 (has links)
by Ng Chi Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 64-65). / Abstracts in English and Chinese. / ABSTRACT --- p.I / ACKNOWLEDGEMENT --- p.II / TABLE OF CONTENTS --- p.III / LIST OF TABLES --- p.VI / LIST OF FIGURES --- p.VII / LIST OF ABBREVIATIONS --- p.X / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Related works --- p.5 / Chapter 1.3 --- Organization of this Thesis --- p.6 / Chapter CHAPTER 2 --- BACKGROUND --- p.7 / Chapter 2.1 --- Introduction to VOD Systems --- p.7 / Chapter 2.1.1 --- Pure unicast VOD System --- p.8 / Chapter 2.1.2 --- Pure multicast VOD System --- p.9 / Chapter 2.1.3 --- Centralized VOD System --- p.9 / Chapter 2.1.4 --- Distributed VOD System --- p.10 / Chapter 2.1.5 --- Hybrid VOD System (DINA) --- p.11 / Chapter 2.1.6 --- Comparisons --- p.12 / Chapter 2.2 --- Interactive Functions --- p.14 / Chapter 2.2.1 --- Speedup --- p.14 / Chapter 2.2.2 --- Split and merge (I and S streams) --- p.14 / Chapter 2.2.3 --- Prerecord --- p.15 / Chapter 2.3 --- Error Recovery --- p.16 / Chapter 2.3.1 --- Pure FEC --- p.17 / Chapter 2.3.2 --- Pure ARQ --- p.17 / Chapter 2.3.3 --- Hybrid ARQ --- p.18 / Chapter 2.3.4 --- Rate-Compatible Punctured Convolutional Codes --- p.18 / Chapter CHAPTER 3 --- HYBRID MULTICAST-UNICAST VOD SYSTEM --- p.21 / Chapter 3.1 --- System Overview --- p.21 / Chapter 3.1.1 --- VSC (Video Server Cluster) --- p.22 / Chapter 3.1.2 --- DIS (Distributed Interactive Server) --- p.24 / Chapter 3.1.3 --- NAK (Negative Acknowledgement Server) --- p.25 / Chapter 3.1.4 --- CS (Client Stations) --- p.26 / Chapter 3.1.5 --- MBN (Multicast Backbone Network) --- p.27 / Chapter 3.1.6 --- LDN (Local Distribution Network) --- p.27 / Chapter 3.2 --- Interactive Functions --- p.28 / Chapter 3.2.1 --- Hybrid Multicast- Unicast --- p.28 / Chapter 3.2.2 --- Pause --- p.30 / Chapter 3.2.3 --- Slow Forward (SF) --- p.33 / Chapter 3.2.4 --- Slow Backward (SB) --- p.35 / Chapter 3.2.5 --- Fast Forward (FF) / Fast Backward (FB) --- p.38 / Chapter 3.2.6 --- Jump Forward (JF) / Jump Backward (JB) --- p.41 / Chapter 3.3 --- System Performance --- p.46 / Chapter 3.3.1 --- System Model --- p.46 / Chapter 3.3.2 --- Simulation Results --- p.47 / Chapter 3.3.3 --- Trade off --- p.53 / Chapter CHAPTER 4 --- DISTRIBUTED TYPE-II HARQ --- p.54 / Chapter 4.1 --- Algorithm Description --- p.54 / Chapter 4.1.1 --- Design details --- p.54 / Chapter 4.1.2 --- Simulation Results --- p.59 / Chapter CHAPTER 5 --- CONCLUSION --- p.62 / BIBLIOGRAPHY --- p.64
44

A server-less architecture for building scalable, reliable, and cost-effective video-on-demand systems.

January 2002 (has links)
Leung Wai Tak. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 58-60). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Abstract --- p.II / 摘要 --- p.III / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Related Works --- p.5 / Chapter 2.1 --- Previous Works --- p.5 / Chapter 2.2 --- Contributions of this Study --- p.7 / Chapter Chapter 3 --- Architecture --- p.9 / Chapter 3.1 --- Data Placement Policy --- p.10 / Chapter 3.2 --- Retrieval and Transmission Scheduling --- p.13 / Chapter 3.3 --- Fault Tolerance --- p.20 / Chapter Chapter 4 --- Performance Modeling --- p.22 / Chapter 4.1 --- Storage Requirement --- p.22 / Chapter 4.2 --- Network Bandwidth Requirement --- p.23 / Chapter 4.3 --- Buffer Requirement --- p.24 / Chapter 4.4 --- System Response Time --- p.27 / Chapter Chapter 5 --- System Reliability --- p.29 / Chapter 5.1 --- System Failure Model --- p.29 / Chapter 5.2 --- Minimum System Repair Capability --- p.32 / Chapter 5.3 --- Redundancy Configuration --- p.35 / Chapter Chapter 6 --- System Dimensioning --- p.37 / Chapter 6.1 --- Storage Capacity --- p.38 / Chapter 6.2 --- Network Capacity --- p.38 / Chapter 6.3 --- Disk Access Bandwidth --- p.39 / Chapter 6.4 --- Buffer Requirement --- p.41 / Chapter 6.5 --- System Response Time --- p.43 / Chapter Chapter 7 --- Multiple Parity Groups --- p.45 / Chapter 7.1 --- System Failure Model --- p.47 / Chapter 7.2 --- Buffer Requirement --- p.47 / Chapter 7.3 --- System Response Time --- p.49 / Chapter 7.4 --- Redundancy Configuration --- p.49 / Chapter 7.5 --- Scalability --- p.51 / Chapter Chapter 8 --- Conclusions and Future Works --- p.53 / Appendix --- p.55 / Chapter A. --- Derivation of the Artificial Admission Delay --- p.55 / Chapter B. --- Derivation of the Receiver Buffer Requirement --- p.56 / Bibliography --- p.58
45

Decentralized periodic broadcasting for large-scale video streaming.

January 2006 (has links)
To Ka Ki. / Thesis submitted in: August 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 55-56). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Chapter Chapter 1 --- INTRODUCTION --- p.5 / Chapter Chapter 2 --- related WORKS --- p.12 / Chapter Chapter 3 --- Decentralization of Periodic Broadcasting --- p.16 / Chapter 3.1 --- Staggered Broadcasting --- p.16 / Chapter 3.2 --- Modified Staggered Broadcasting --- p.17 / Chapter Chapter 4 --- PEERS SYNCHRONIZATION --- p.21 / Chapter 4.1 --- Integrating PCS with Periodic Broadcasting --- p.22 / Chapter 4.2 --- Distributed PCS --- p.23 / Chapter Chapter 5 --- Performance Evaluations of Decentralized Periodic Broadcasting Architecture --- p.27 / Chapter 5.1 --- Sensitivity to Clock Drift --- p.28 / Chapter 5.2 --- System Dynamic Behavior --- p.30 / Chapter Chapter 6 --- P-NICE --- p.33 / Chapter 6.1 --- The Original NICE Protocol --- p.34 / Chapter 6.2 --- Parallel Overlay Architecture --- p.35 / Chapter 6.3 --- Control Overheads --- p.37 / Chapter Chapter 7 --- Performance Evaluations of P-NICE --- p.39 / Chapter 7.1 --- End-to-End Packet Delivery Ratio --- p.40 / Chapter 7.2 --- Utilization of Network Links --- p.41 / Chapter 7.3 --- Convergence Time of End-to-End Packet Delivery Ratio --- p.44 / Chapter 7.4 --- Effect of Number of Overlays --- p.45 / Chapter 7.5 --- End-to-End Data Delivery Delay --- p.47 / Chapter 7.6 --- Load Balance of Overlays --- p.47 / Chapter 7.7 --- Peers Reception Quality --- p.48 / Chapter 7.8 --- Control Overheads --- p.51 / Chapter Chapter 8 --- Conclusions --- p.53 / Bibliography --- p.55
46

Replication and incentive mechanisms design in peer-to-peer video-on-demand systems. / CUHK electronic theses & dissertations collection

January 2012 (has links)
點對點視頻點播是架構于互網上的熱門應用,旨在提供高質視頻服務。應用點對點技術的優勢在於,系統可用用戶資源以滿足其他用戶的觀賞需求,從而提高系統可擴展性并低運營成本。在該系統中存在以下關鍵設計因素。其一,在給定用戶資源時,如何以分佈式和動態性方法有效用這些資源;其二,考慮用戶自私性,如何激他們貢獻本地資源。 / 點對點視頻點播系統具有高動態性,非同步性及質性;相比文件共享系統還需大帶寬支持。這些特性使得解決以上技術問題充滿挑戰,因而激發我們的研究。我們試圖回答以下問題: / 如何確定存儲空間對各視頻的最佳分配比,從而最小化服務器負擔? / 如何設計高效激機制使用戶於貢獻他們的本地資源? / 我們首先關注最佳複製策。我們回答(1)在給定視頻條件下,如何確定視頻最佳複製比;(2)如何通過分佈式動態算法獲得這樣的最佳複製比。我們將視頻複製技術表達為最優化問題,显示傳統比複製法并非最優,而最優比應正比于文中定義的“欠缺帶寬。我們通過“被動替換算法與“主動推送算法以達到最優複製比,顯示我們的算法可使得服務器負擔大幅下以及服務質素顯著提高。 / 我們而後關注激機制設計。系統運營商需激用戶貢獻上載帶寬以傳輸據,以及本地存儲空間以存儲視頻。我們分解這個設計問題,并為它們逐一設計基於獎賞的激機制。(1)上載帶寬激。用戶根據貢獻帶寬受到獎賞。我們用博弈模型分析運營商與用戶之間的交互。我們推導出博弈均衡,分析系統高效性并研究多重博弈設定下的長期交互特性。(2)分佈存儲激。用戶根據緩存視頻受到獎賞。我們以優化模型刻畫視頻最佳獎賞價格。我們在漸進系統中推導出最優獎賞價格,然後將結果推廣至多種系統環境。 / 總而言之,該文從學建模、博弈分析、算法設計與性能評估等諸多角,解決點對點視頻點播系統中的資源獲取與分配策。 / Peer-to-Peer Video-on-Demand (P2P-VoD) is a popular Internet application which aims to provide a high quality video service to users. The advantage of using the P2P technology is that the system can utilize peers’ resources so as to satisfy other peers’ viewing requirement, thereby improving the system scalability and reducing the operating cost. There are two key design issues in P2P-VoDs. First, given the distributed resources of peers, what is the most efficient manner to utilize them in a distributed and dynamic fashion. Second, given the selfish nature of peers, how to incentivize the peers to contribute their local resources. / A P2P-VoD system is highly dynamic, asynchronous and heterogenous in nature. In addition, it requires a much higher bandwidth resource as compared with file sharing applications. These features make it challenging to solve the above technical problems, and hence motivate our work. In particular, we aim to answer: / How to determine the optimal ratios of storage space that should be assigned to each video, such that the content server’s workload can be minimized? / How to design effective and efficient incentive mechanisms so as to stimulate the peers to contribute their local resources? / We first focus on the optimal replication strategy. In particular, we answer (a) what is the optimal replication ratio of a video in terms of its popularity, and (b) how to achieve these optimal ratios in a distributed and dynamic fashion. We formulate the video replication as an optimization problem, and show that the conventional wisdom of using the proportional replication strategy is “sub-optimal“. The optimal replication ratios should be proportional to the “deficit bandwidth which we define in the thesis. We utilize “passive replacement policy“ and “active push policy“ to achieve the optimal replication ratios and show how to greatly reduce server’s workload and improve streaming quality via our distributed algorithms. / We next focus on incentive mechanisms design. The content providers need to incentivize the peers to contribute their upload capacity to delivery data, and local storage space to cache the videos. We decompose the problems and design reward-based incentive mechanisms for them respectively. (a) Incentivizing upload capacity. Each peer is rewarded based on its dedicated upload bandwidth. We analyze the interaction between a content provider and the peers using game theory. We derive a unique equilibrium, analyze the system efficiency and study the long term interactions under a repeated game setting. (b) Incentivizing distributed caching. Each peer is rewarded based on the videos they cache. We characterizes the optimal reward price using optimization. In particular, we first derive the optimal prices to obtain the desired amount of replicas in an asymptotic system, and then extend our results to adapt to various system environments. / To summarize, this thesis addresses the resource acquisition and allocation problems in P2P-VoD systems via mathematical modeling, game analysis, algorithms design and performance evaluations. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wu, Weijie. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 129-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.v / Contents --- p.ix / List of Figures --- p.xiii / List of Tables --- p.xv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Peer-to-Peer Networks --- p.2 / Chapter 1.1.1 --- Classification of P2P Networks --- p.2 / Chapter 1.1.2 --- Applications of P2P Services --- p.4 / Chapter 1.2 --- P2P Video-on-Demand Systems --- p.4 / Chapter 1.2.1 --- General Architecture --- p.4 / Chapter 1.2.2 --- Key Advantages of P2P-VoDs --- p.6 / Chapter 1.3 --- Motivation --- p.7 / Chapter 1.4 --- Challenges --- p.8 / Chapter 1.5 --- Contributions --- p.10 / Chapter 1.6 --- A General System Model on P2P-VoDs --- p.12 / Chapter 1.7 --- Thesis Structure and Organization --- p.15 / Chapter 2 --- Optimal Replication Strategies in P2P-VoD Systems --- p.17 / Chapter 2.1 --- Chapter Overview --- p.17 / Chapter 2.2 --- Mathematical Model --- p.19 / Chapter 2.2.1 --- Basic System Assumptions and Peer Scheduling Policy --- p.19 / Chapter 2.2.2 --- Server’s Workload --- p.22 / Chapter 2.2.3 --- Discussion on Peer Operations --- p.26 / Chapter 2.2.4 --- Impact of Replication on Reducing the Server’s Workload --- p.27 / Chapter 2.3 --- Optimal Replication Ratios to Minimize Server’s Workload --- p.30 / Chapter 2.3.1 --- Operation Modes --- p.30 / Chapter 2.3.2 --- Characteristics of Deficit Bandwidth --- p.31 / Chapter 2.3.3 --- Characterizing the Optimal Replication Strategy --- p.34 / Chapter 2.3.4 --- Discussion on Heterogeneous Video Playback Rates --- p.36 / Chapter 2.4 --- Algorithms to Control Replication Ratios --- p.38 / Chapter 2.4.1 --- Passive Adjustment via Replacement Algorithm --- p.39 / Chapter 2.4.2 --- Active Adjustment via Push Strategy --- p.40 / Chapter 2.5 --- Performance Evaluation --- p.43 / Chapter 2.5.1 --- Performance of Replacement Algorithm --- p.43 / Chapter 2.5.2 --- Performance of Push Algorithm --- p.49 / Chapter 2.6 --- Chapter Summary --- p.51 / Chapter 3 --- Incentivizing Upload Capacity in P2P-VoD Systems --- p.53 / Chapter 3.1 --- Chapter Overview --- p.53 / Chapter 3.2 --- Peers’ Viewing Behavior and Reward-based Scheme --- p.55 / Chapter 3.2.1 --- Peers’ Viewing Behavior --- p.55 / Chapter 3.2.2 --- Reward-based Incentive Scheme --- p.57 / Chapter 3.3 --- Peers’ Contribution and Content Provider’s Cost --- p.58 / Chapter 3.3.1 --- Distribution of Peers in Different Video Segments --- p.58 / Chapter 3.3.2 --- Content Provider’s Upload Cost --- p.61 / Chapter 3.4 --- Game Theoretic Analysis on Incentive Scheme --- p.62 / Chapter 3.4.1 --- Stackelberg Game Model --- p.63 / Chapter 3.4.2 --- Existence and Uniqueness of Stackelberg Equilibrium --- p.64 / Chapter 3.4.3 --- Efficiency of Stackelberg Equilibrium --- p.67 / Chapter 3.4.4 --- General Reward Scheme --- p.72 / Chapter 3.4.5 --- Repeated Game Model --- p.73 / Chapter 3.5 --- Performance Evaluation --- p.77 / Chapter 3.6 --- Discussion on Practical Issues --- p.82 / Chapter 3.6.1 --- System Heterogeneity --- p.82 / Chapter 3.6.2 --- P2P-VoD System with Caching --- p.83 / Chapter 3.6.3 --- Cheating Prevention Guarantee --- p.84 / Chapter 3.7 --- Chapter Summary --- p.84 / Chapter 4 --- Incentivizing Distributed Caching in P2P-VoD Systems --- p.86 / Chapter 4.1 --- Chapter Overview --- p.86 / Chapter 4.2 --- Mathematical Model --- p.88 / Chapter 4.2.1 --- Preliminaries --- p.88 / Chapter 4.2.2 --- Peers’ Caching Behaviors --- p.91 / Chapter 4.2.3 --- Cache state distribution of peers of type m --- p.93 / Chapter 4.2.4 --- Cache State of the System --- p.95 / Chapter 4.2.5 --- Design Objectives of Pricing Schemes --- p.96 / Chapter 4.3 --- Asymptotic Analysis --- p.98 / Chapter 4.3.1 --- Cache State of Peers --- p.99 / Chapter 4.3.2 --- Conservative Pricing Problem --- p.102 / Chapter 4.3.3 --- Strategic Pricing Problem --- p.105 / Chapter 4.4 --- Generalizations and Extensions --- p.106 / Chapter 4.4.1 --- Viewing-Caching Decoupling --- p.107 / Chapter 4.4.2 --- General Sensitivity Model --- p.108 / Chapter 4.4.3 --- Non-Asymptotic System --- p.111 / Chapter 4.4.4 --- Pricing before Reaching the Steady State --- p.113 / Chapter 4.5 --- Performance Evaluation --- p.115 / Chapter 4.6 --- Chapter Summary --- p.119 / Chapter 5 --- Related Work --- p.120 / Chapter 5.1 --- Related Work on Replication Strategy --- p.120 / Chapter 5.2 --- Related Work on Incentive Mechanisms Design --- p.122 / Chapter 6 --- Conclusion and FutureWork --- p.125 / Chapter 6.1 --- Conclusion --- p.125 / Chapter 6.2 --- Future work --- p.126 / Chapter 6.2.1 --- Extensions for Various Practical Issues --- p.126 / Chapter 6.2.2 --- Incentive and Resource Allocation in Other Applications --- p.127 / Bibliography --- p.129
47

Modeling and analysis of P2P VoD system. / Modeling and analysis of peer-to-peer video on demand system

January 2012 (has links)
点对点网络是今年兴起的一个热门研究课题。 点对点网络有非常好的文件分发能力, 在传统的服务器客模式下, 服务器需要为每位客建立独立的链接。随着用的增加服务器的能力很快会变成瓶颈。点对点网络的优势在于能够通过下载相同内容的客共享交换内容, 从而利用每位客的上传带宽.基于这个特点,即使没有服务器的帮助, 只要客都无私的共享自己的内容, 点对点网络可以以非常高的效率分发大文件。 目前已经有很对研究成果是关于点对点网络的体系结构设计和网络协议设计。但随着文件大小和数量的快速增长, 客除了贡献带宽还会贡献一块硬盘来缓存一些自己并不感兴趣的内容来增加客间互相帮助的概率。尤其是视频点播应用的兴起给点对点网络的内容传输带来了新的挑战。例如如何能保证所有客流畅的点播视频,以及如何优化每个客缓存的内容来最小化服务器带宽需求。在本篇论文中, 我们将集中讨论点对点视频点播系统并解决以下问题: / 我们的目的是节省服务器带宽。一个最基本的问题是客节点的最优缓存替换策略问题。首先我们定义了完美请求调度策略,在这个调度策略的基础上提出RLB 缓存替换策略从而得到最小化服务器带宽。 / 第二个问题是不同的请求调度策略和最优的缓存替换策略之间是如何相互影响的。我们提出了FSBD 模型。通过研究每个客能发出的请求数目,我们恩能够比较不同的缓存替换策略和不同的调度策略之间的关系。 / 最后一个问题,我们研究了点对点视频点播系统在电影数量远远多于客数量的极端情况。在这种情况下, 由于客只能贡献非常少量的硬盘来缓存电影, 提供电影的覆盖和提高视频点播系统的吞吐量是一个互相矛盾的问题。两者不能同时达到最优。 / 除了以上的理论分析, 我们通过模拟试验来验证理论模型的正确性。 此外我们还提出了非常简单有效的分布式缓存替换策略用于实际系统的实现。相信以上的研究工作对于点对点视频系统的设计和实现有重要的帮助。 / Peer-to-Peer (P2P) systems become a hot research topic in recent years because of their excellent ability for content distribution. In traditional Client/Server(C/S) mode, the server must serve each user directly. The server capacity is the bottleneck when user population becomes large. The power of P2P network is to encourage peers to share common content with each other to offload server. The P2P systems distribute content very efficiently if all peers help others selflessly with minimal support from the server. There are many works dedicated to the architecture and protocol design for P2P systems. These works study how to organize peers to exchange content efficiently. As content size and content population are growing very fast today, P2P networks are used to support Video on Demand (VoD) streaming service. For VoD streaming, besides bandwidth, the peers are required to contribute storage to cache some content that they may not be interested in. The new challenges include how to guarantee that all peers can play video smoothly and how to cache the content at different peers to minimize server load . In this thesis, we study the following problems in a P2P VoD streaming system: / What the optimal movie replication strategy to minimize server load is. To study this problem, we first make an assumption to simplify the P2P service model. We assume that all peers follow a Perfect Fair Sharing (PFS) scheduling strategy. Based on this setup, we proposed Random Load Balance (RLB) algorithm to achieve minimum server load. We derive analytical bounds on the achieved server load. / Next, We observe that different P2P scheduling strategies lead to different “optimal replication strategies. Our second setup is to relax the assumption of perfect fair sharing scheduling by proposing a Fair Sharing with Bounded Degree (FSBD) model, parameterized by the maximum number of peers that can be used to serve a single request. PFS is a special case of FSBD. We compare different replication strategies for different in-degree bounds and see how and why different replication strategies are favored depending on the in-degree. / For the last problem, we let the movie population become large and assume that there is some skewness in movie popularity. Then peers can’t reduce server load and provide availability of all movies at the same time. In other words, peers must be selective in replicating sufficiently popular movies. It is a tradeoff between coverage of movies and streaming throughput provided by the P2P system. / Besides analysis, we also use simulation to validate our models. As a robust solution under different P2P service models, we proposed a simple adaptive movie replication algorithm with computation efficiency. Our study leads to several fundamental insights for the design of P2P VoD systems in practice. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhou, Yipeng. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 162-170). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.i / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.2 / Chapter 1.2 --- P2P VoD Streaming System --- p.6 / Chapter 1.3 --- Contribution --- p.11 / Chapter 1.4 --- Organization --- p.12 / Chapter 2 --- Model --- p.14 / Chapter 2.1 --- Assumptions and Notations --- p.15 / Chapter 2.2 --- User Behavior Model --- p.19 / Chapter 2.3 --- Movie Popularity --- p.22 / Chapter 2.4 --- Optimizing Server Load --- p.25 / Chapter 3 --- Analysis --- p.30 / Chapter 3.1 --- Request Scheduling Strategy --- p.31 / Chapter 3.2 --- Fixed Bandwidth Allocation --- p.33 / Chapter 3.2.1 --- FBA with Homogeneous Peers --- p.33 / Chapter 3.2.2 --- FBA with Heterogeneous Peers --- p.37 / Chapter 3.3 --- Perfect Fair Sharing --- p.37 / Chapter 3.3.1 --- PFS with Homogeneous Peers --- p.41 / Chapter 3.3.2 --- PFS with Heterogeneous Peers --- p.48 / Chapter 3.4 --- Fair Sharing with Fixed Degree --- p.50 / Chapter 3.5 --- FBA v.s. PFS v.s. FSFD --- p.53 / Chapter 3.6 --- Fair Sharing with Bounded Degree --- p.55 / Chapter 4 --- Adaptive Movie Replication Algorithms --- p.62 / Chapter 4.1 --- Adaptive RLB Algorithm --- p.63 / Chapter 4.2 --- Distributed Adaptive Replication Algorithm --- p.66 / Chapter 4.2.1 --- Other Algorithms --- p.70 / Chapter 5 --- Simulation --- p.73 / Chapter 5.1 --- Simulation Setting --- p.74 / Chapter 5.2 --- Simulation for PFS --- p.76 / Chapter 5.2.1 --- Stationary demand and static replication assignment --- p.77 / Chapter 5.2.2 --- Evaluate adaptive replication algorithms --- p.81 / Chapter 5.2.3 --- Performance analysis and discussion --- p.85 / Chapter 5.2.4 --- Copy Distribution of ARLB --- p.89 / Chapter 5.3 --- Simulation for FBA, FSFD and FSBD --- p.91 / Chapter 5.3.1 --- Model Validation --- p.91 / Chapter 5.3.2 --- Test of DAR Algorithm --- p.93 / Chapter 5.3.3 --- Robustness Validation --- p.96 / Chapter 6 --- Division of Labor --- p.102 / Chapter 6.1 --- Background: models and algorithms --- p.103 / Chapter 6.2 --- Availability versus Throughput --- p.106 / Chapter 6.2.1 --- ATD and its Drawbacks --- p.107 / Chapter 6.2.2 --- Coverage Assured Replication --- p.110 / Chapter 6.2.3 --- Automatic Division of Labor --- p.113 / Chapter 6.3 --- Optimal Coverage --- p.115 / Chapter 6.3.1 --- Save Most Popular Movies for P2P --- p.115 / Chapter 6.3.2 --- The Value of Optimal K --- p.118 / Chapter 6.3.3 --- Performance with or without CA --- p.121 / Chapter 6.4 --- Sensitivity --- p.122 / Chapter 6.4.1 --- θ versus K* --- p.122 / Chapter 6.4.2 --- The Effect of Popularity Skewness:θ --- p.123 / Chapter 6.4.3 --- System Parameters versus K* --- p.124 / Chapter 6.4.4 --- The Effect of System Parameters --- p.126 / Chapter 7 --- Related Work --- p.131 / Chapter 8 --- Conclusion --- p.141 / Chapter A --- Equation Derivation --- p.144 / Bibliography --- p.162
48

Partido dos trabalhadores : a influ?ncia da pr?xis na identidade interna

Todt, Marcos Leite de Matos 27 March 2013 (has links)
Made available in DSpace on 2015-04-14T14:46:13Z (GMT). No. of bitstreams: 1 449066.pdf: 2103081 bytes, checksum: 44c65a83dc8c5de5d5a207d123574fff (MD5) Previous issue date: 2013-03-27 / This study aims to verify whether there is a relationship between praxis and identification with the left-wing most positions within the Partido dos Trabalhadores (Workers Party, PT). Having as reference for analysis dialectical materialism, especially the studies from Gramsci on the construction of world concepts and hegemony, our hypothesis is that the relationship exists, and that individuals who have greater wealth in collective activities have greater tendency to assume a speech and left-wing thinking, that to legitimize itself first needs to deconstruct the immediate code of explanation and interpretation of reality. In contrast, those with few collective experiences not only tend to suffer greater influence of the discourse of common sense, but also take you into the party. This would help to understand the passage of PT from the left-wing to the center of the brazilian political spectrum, relating changes in the internal life of the party and the significant decrease in militancy spaces with more moderate policies of PT and its governments. We applied one hundred and nine questionnaires and conducted semistructured interviews with 21 members of the PT in Porto Alegre. We found that the affiliates who have a higher level of praxis (in which we classify as militants and affiliated with praxis) expressed placements that in our previous systematic, considered as leftist. Meanwhile, the affiliates who have lower level of praxis (we call pure affiliated) proved far these positions / O presente trabalho busca verificar se h? rela??o entre pr?xis e identifica??o com posi??es mais ? esquerda dentro do Partido dos Trabalhadores (PT). Tendo como refer?ncia para an?lise o materialismo dial?tico, em especial os estudos de Gramsci sobre a constru??o de concep??es de mundo e hegemonia, nossa hip?tese ? de que a rela??o existe, e que os indiv?duos que t?m maior riqueza em atividades coletivas possuem tend?ncia maior a assumir um discurso e pensamento de esquerda, que, para se legitimar, necessita primeiro desconstruir o c?digo imediato de explica??o e interpreta??o da realidade. Em contraposi??o, quem tem poucas experi?ncias coletivas tende n?o apenas a sofrer maior influ?ncia do discurso do senso comum, mas tamb?m a lev?-lo para dentro do partido. Isso ajudaria a entender o deslocamento do PT da esquerda em dire??o ao centro no espectro pol?tico brasileiro, relacionando as modifica??es na vida interna do partido e a expressiva diminui??o dos espa?os de milit?ncia com as pol?ticas mais moderadas do PT e dos governos petistas. Aplicamos cento e nove question?rios e realizamos entrevista semiestruturada com 21 filiados ao PT em Porto Alegre. Verificamos que os filiados que possuem maior n?vel de pr?xis (que classificamos em militantes e filiados com pr?xis) expressaram os posicionamentos que, em nossa sistematiza??o pr?via, consideramos como de esquerda. Enquanto isso, os filiados que possuem menor n?vel de pr?xis (que denominamos filiados puros) se mostraram distantes dessas posi??es
49

Parallel replication for distributed video-on-demand systems.

January 1997 (has links)
Lie, Wai-Kwok Peter. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 79-83). / Abstract --- p.i / Acknowledgments --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background & Related Work --- p.5 / Chapter 2.1 --- Early Work on Multimedia Servers --- p.6 / Chapter 2.2 --- Compression of Multimedia Data --- p.6 / Chapter 2.3 --- Multimedia File Systems --- p.7 / Chapter 2.4 --- Scheduling Support for Multimedia Systems --- p.8 / Chapter 2.5 --- Inter-media Synchronization --- p.9 / Chapter 2.6 --- Related Work on Replication in VOD Systems --- p.9 / Chapter 3 --- System Model --- p.12 / Chapter 4 --- Replication Methodology --- p.15 / Chapter 4.1 --- Replication Triggering Policy --- p.16 / Chapter 4.2 --- Source & Target Nodes Selection Policies --- p.17 / Chapter 4.3 --- Replication Policies --- p.18 / Chapter 4.3.1 --- Policy 1: Injected Sequential Replication --- p.20 / Chapter 4.3.2 --- Policy 2: Piggybacked Sequential Replication --- p.22 / Chapter 4.3.3 --- Policy 3: Injected Parallel Replication --- p.25 / Chapter 4.3.4 --- Policy 4: Piggybacked Parallel Replication --- p.28 / Chapter 4.3.5 --- Policy 5: Injected & Piggybacked Parallel Replication --- p.34 / Chapter 4.3.6 --- Policy 6: Multi-Source Injected & Piggybacked Parallel Replication --- p.36 / Chapter 4.4 --- Dereplication Policy --- p.37 / Chapter 5 --- Distributed Architecture for VOD Server --- p.39 / Chapter 5.1 --- Server Node --- p.40 / Chapter 5.2 --- Movie Manager --- p.42 / Chapter 5.3 --- Metadata Manager --- p.42 / Chapter 5.4 --- Protocols for Distributed VOD Architecture --- p.43 / Chapter 5.4.1 --- Protocol for Servicing New Customers --- p.43 / Chapter 5.4.2 --- Protocol for Servicing Existing Customers --- p.45 / Chapter 5.4.3 --- Protocol for Single/Multi-Source Injected & Parallel Replication --- p.46 / Chapter 5.4.4 --- Protocol for Dereplication --- p.48 / Chapter 5.5 --- Failure Handling --- p.49 / Chapter 5.5.1 --- Handling of Server Node Failures --- p.50 / Chapter 5.5.2 --- Handling of Movie Manager Failures --- p.52 / Chapter 6 --- Results --- p.55 / Chapter 6.1 --- Performance Metric --- p.56 / Chapter 6.2 --- Simulation Environment --- p.58 / Chapter 6.3 --- Results of Experiments without Dereplication --- p.59 / Chapter 6.3.1 --- Comparison of Different Replication Policies --- p.60 / Chapter 6.3.2 --- Effect of Early Acceptance/Migration --- p.61 / Chapter 6.3.3 --- Answer to the Resources Consumption Tradeoff issue --- p.62 / Chapter 6.3.4 --- Effect of Varying Movie Popularity Skewness --- p.64 / Chapter 6.3.5 --- Effect of Varying Replication Threshold --- p.64 / Chapter 6.3.6 --- Comparison of Different Target Node Selection Policies --- p.65 / Chapter 6.4 --- Overall Impact of Dynamic Replication --- p.66 / Chapter 7 --- Comparison with BSR-based Policy --- p.71 / Chapter 8 --- Conclusions --- p.75 / Chapter 8.1 --- Summary --- p.75 / Chapter 8.2 --- Future Research Directions --- p.76 / Bibliography --- p.78
50

Server's anonymity attack and protection of P2P-Vod systems. / Server's anonymity attack and protection of peer-to-peer video on demand systems

January 2010 (has links)
Lu, Mengwei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (p. 52-54). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Introduction of P2P-VoD Systems --- p.5 / Chapter 2.1 --- Major Components of the System --- p.5 / Chapter 2.2 --- Peer Join and Content Discovery --- p.6 / Chapter 2.3 --- Segment Sizes and Replication Strategy --- p.7 / Chapter 2.4 --- Piece Selection --- p.8 / Chapter 2.5 --- Transmission Strategy --- p.9 / Chapter 3 --- Detection Methodology --- p.10 / Chapter 3.1 --- Capturing Technique --- p.11 / Chapter 3.2 --- Analytical Framework --- p.15 / Chapter 3.3 --- Results of our Detection Methodology --- p.24 / Chapter 4 --- Protective Architecture --- p.25 / Chapter 4.1 --- Architecture Overview --- p.25 / Chapter 4.2 --- Content Servers --- p.27 / Chapter 4.3 --- Shield Nodes --- p.28 / Chapter 4.4 --- Tracker --- p.29 / Chapter 4.5 --- A Randomized Assignment Algorithm --- p.30 / Chapter 4.6 --- Seeding Algorithm --- p.31 / Chapter 4.7 --- Connection Management Algorithm --- p.33 / Chapter 4.8 --- Advantages of the Shield Nodes Architecture --- p.33 / Chapter 4.9 --- Markov Model for Shield Nodes Architecture Against Single Track Anonymity Attack --- p.35 / Chapter 5 --- Experiment Result --- p.40 / Chapter 5.1 --- Shield Node architecture against anonymity attack --- p.40 / Chapter 5.1.1 --- Performance Analysis for Single Track Anonymity Attack --- p.41 / Chapter 5.1.2 --- Experiment Result on PlanetLab for Single Track Anonymity Attack --- p.42 / Chapter 5.1.3 --- Parallel Anonymity Attack --- p.44 / Chapter 5.2 --- Shield Nodes architecture-against DoS attack --- p.45 / Chapter 6 --- Related Work --- p.48 / Chapter 7 --- Future Work --- p.49 / Chapter 8 --- Conclusion --- p.50

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