174 research outputs found

    Use of Modern Birth Control Methods Among

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    ABSTRACT This paper studied the extent of utilization of Modern Birth Control Methods (MBCM) among rural dwellers in Imo State Nigeria. Three hundred and sixty households were randomly selected and data were obtained from them with the use of questionnaires and Focus Group Discussion. The results showed that only 30% of the respondents used MBCM while 57% of them used the traditional birth control methods. The most popular modern method was the condom (24.2%). This was followed by the IUD, used by only 2.5% of the respondents. Some of the identified factors that hindered the use of MBCM included perceived negative health reaction, fear of the unknown effects, cost, spouse's disapproval, religious belief and inadequate information. For a better understanding and utilization of MBCM, it is recommended that adequate educational campaign should be mounted in the rural areas on the advantages of MBCM. This campaign should target the men the more because they make the major decisions on MBCM use. RÉSUMÉ L'utilisation des méthodes modernes de contrôle des naissances au sein des communautés rurales dans l'état d'Imo, Nigéria L'article a étudié l'ampleur de l'utilisation des méthodes modernes de contrôle des naissances (MMCN) au sein des villageois dans l'Etat d'Imo, Nigeria. Trois-cent-soixante familles ont été sélectionnées au hasard et des données ont été obtenues à l'aide des questionnaires et des Discussions en Groupes Cible. Les résultats ont montré que seuls 30% des gens interroges utilisaient les MMCN alors que 57% d'eux utilisaient les méthodes traditionnelles de contrôle des naissances. La méthode moderne la plus populaire était le préservatif (24,2%). Le DIU venait après, utilisé par seuls 2,5% des personnes interrogées. Quelques facteurs identifies qui ont entravé l'utilisation des MMCN ont compris une réaction médicale négative perçue, la crainte des effets inconnus, le coût, la désapprobation de l'époux, la croyance religieuse et l'information insuffisante. Pour une meilleure compréhension et utilisation des MMCN, nous proposons qu'une campagne éducative adéquate soit montée dans les régions rurales sur les avantages des MMCN. Cette campagne devrait avoir comme cibles les hommes plus que les femmes parce qu'ils prennent les décisions principales sur l'utilisation des MMCN. (Rev Af

    A Utility-based QoS Model for Emerging Multimedia Applications

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    Existing network QoS models do not sufficiently reflect the challenges faced by high-throughput, always-on, inelastic multimedia applications. In this paper, a utility-based QoS model is proposed as a user layer extension to existing communication QoS models to better assess the requirements of multimedia applications and manage the QoS provisioning of multimedia flows. Network impairment utility functions are derived from user experiments and combined to application utility functions to evaluate the application quality. Simulation is used to demonstrate the validity of the proposed QoS model

    Correlated Resource Models of Internet End Hosts

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    Understanding and modelling resources of Internet end hosts is essential for the design of desktop software and Internet-distributed applications. In this paper we develop a correlated resource model of Internet end hosts based on real trace data taken from the SETI@home project. This data covers a 5-year period with statistics for 2.7 million hosts. The resource model is based on statistical analysis of host computational power, memory, and storage as well as how these resources change over time and the correlations between them. We find that resources with few discrete values (core count, memory) are well modeled by exponential laws governing the change of relative resource quantities over time. Resources with a continuous range of values are well modeled with either correlated normal distributions (processor speed for integer operations and floating point operations) or log-normal distributions (available disk space). We validate and show the utility of the models by applying them to a resource allocation problem for Internet-distributed applications, and demonstrate their value over other models. We also make our trace data and tool for automatically generating realistic Internet end hosts publicly available

    Stochastic Analysis of a Churn-Tolerant Structured Peer-to-Peer Scheme

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    We present and analyze a simple and general scheme to build a churn (fault)-tolerant structured Peer-to-Peer (P2P) network. Our scheme shows how to "convert" a static network into a dynamic distributed hash table(DHT)-based P2P network such that all the good properties of the static network are guaranteed with high probability (w.h.p). Applying our scheme to a cube-connected cycles network, for example, yields a O(logN)O(\log N) degree connected network, in which every search succeeds in O(logN)O(\log N) hops w.h.p., using O(logN)O(\log N) messages, where NN is the expected stable network size. Our scheme has an constant storage overhead (the number of nodes responsible for servicing a data item) and an O(logN)O(\log N) overhead (messages and time) per insertion and essentially no overhead for deletions. All these bounds are essentially optimal. While DHT schemes with similar guarantees are already known in the literature, this work is new in the following aspects: (1) It presents a rigorous mathematical analysis of the scheme under a general stochastic model of churn and shows the above guarantees; (2) The theoretical analysis is complemented by a simulation-based analysis that validates the asymptotic bounds even in moderately sized networks and also studies performance under changing stable network size; (3) The presented scheme seems especially suitable for maintaining dynamic structures under churn efficiently. In particular, we show that a spanning tree of low diameter can be efficiently maintained in constant time and logarithmic number of messages per insertion or deletion w.h.p. Keywords: P2P Network, DHT Scheme, Churn, Dynamic Spanning Tree, Stochastic Analysis

    How do people with eating disorders experience the stigma associated with their condition? A mixed-methods systematic review

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    Background: Public opinion research shows that eating disorders (EDs) are a major target of stigmatisation. To understand the implications of this stigma, research investigating how stigma is experienced by individuals with EDs is critical. Aims: This paper aims to collate, evaluate and synthesise the extant empirical research illuminating how people with EDs experience the stigma associated with their condition. Method: A systematic mixed-methods literature search was performed. Articles that met a specified set of inclusion criteria underwent a quality assessment and thematic synthesis. Results: 29 articles were included in the review. Studies were mostly qualitative and of reasonable methodological quality. The literature was characterised by five research themes, illuminating (i) the nature and prevalence of stigma experienced, (ii) stigma in families, (iii) stigma in healthcare contexts, (iv) self-stigmatisation and illness concealment, and (v) stigma resistance. Conclusions: The reviewed research showed that people with EDs have extensive experience of stigma in diverse settings. They report that stigma has negative implications for their psychological wellbeing and likelihood of help-seeking. However, research also shows that people with EDs actively seek to resist and challenge stigma. The review identifies the outstanding gaps and weaknesses in this literature

    A Two-Stage Multi-Objective Optimization of Erasure Coding in Overlay Networks

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    In the recent years, overlay networks have emerged as a crucial platform for deployment of various distributed applications. Many of these applications rely on data redundancy techniques, such as erasure coding, to achieve higher fault tolerance. However, erasure coding applied in large scale overlay networks entails various overheads in terms of storage, latency and data rebuilding costs. These overheads are largely attributed to the selected erasure coding scheme and the encoded chunk placement in the overlay network. This paper explores a multi-objective optimization approach for identifying appropriate erasure coding schemes and encoded chunk placement in overlay networks. The uniqueness of our approach lies in the consideration of multiple erasure coding objectives such as encoding rate and redundancy factor, with overlay network performance characteristics like storage consumption, latency and system reliability. Our approach enables a variety of tradeoff solutions with respect to these objectives to be identified in the form of a Pareto front. To solve this problem, we propose a novel two stage multiobjective evolutionary algorithm, where the first stage determines the optimal set of encoding schemes, while the second stage optimizes placement of the corresponding encoded data chunks in overlay networks of varying sizes. We study the performance of our method by generating and analyzing the Pareto optimal sets of tradeoff solutions. Experimental results demonstrate that the Pareto optimal set produced by our multi-objective approach includes and even dominates the chunk placements delivered by a related state-of-the-art weighted sum method

    De-ossifying the Internet Transport Layer : A Survey and Future Perspectives

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    ACKNOWLEDGMENT The authors would like to thank the anonymous reviewers for their useful suggestions and comments.Peer reviewedPublisher PD

    A two-level Markov model for packet loss in UDP/IP-based real-time video applications targeting residential users

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    The packet loss characteristics of Internet paths that include residential broadband links are not well understood, and there are no good models for their behaviour. This compli- cates the design of real-time video applications targeting home users, since it is difficult to choose appropriate error correction and concealment algorithms without a good model for the types of loss observed. Using measurements of residential broadband networks in the UK and Finland, we show that existing models for packet loss, such as the Gilbert model and simple hidden Markov models, do not effectively model the loss patterns seen in this environment. We present a new two-level Markov model for packet loss that can more accurately describe the characteristics of these links, and quantify the effectiveness of this model. We demonstrate that our new packet loss model allows for improved application design, by using it to model the performance of forward error correction on such links

    Design space analysis for modeling incentives in distributed systems

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    Distributed systems without a central authority, such as peer-to-peer (P2P) systems, employ incentives to encourage nodes to follow the prescribed protocol. Game theoretic analysis is often used to evaluate incentives in such systems. However, most game-theoretic analyses of distributed systems do not adequately model the repeated interactions of nodes inherent in such systems. We present a game-theoretic analysis of a popular P2P protocol, Bit-Torrent, that models the repeated interactions in such protocols. We also note that an analytical approach for modeling incentives is often infeasible given the complicated nature of most deployed protocols. In order to comprehensively model incentives in complex protocols, we propose a simulation-based method, which we call Design Space Analysis (DSA). DSA provides a tractable analysis of competing protocol variants within a detailed design space. We apply DSA to P2P file swarming systems. With extensive simulations we analyze a wide-range of protocol variants and gain insights into their robustness and performance. To validate these results and to demonstrate the efficacy of DSA, we modify an instrumented BitTorrent client and evaluate protocols discovered using DSA. We show that they yield higher system performance and robustness relative to the reference implementation

    Reverse Engineering the Peer to Peer Streaming Media System

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