7,924 research outputs found

    Overlapping of Communication and Computation and Early Binding: Fundamental Mechanisms for Improving Parallel Performance on Clusters of Workstations

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    This study considers software techniques for improving performance on clusters of workstations and approaches for designing message-passing middleware that facilitate scalable, parallel processing. Early binding and overlapping of communication and computation are identified as fundamental approaches for improving parallel performance and scalability on clusters. Currently, cluster computers using the Message-Passing Interface for interprocess communication are the predominant choice for building high-performance computing facilities, which makes the findings of this work relevant to a wide audience from the areas of high-performance computing and parallel processing. The performance-enhancing techniques studied in this work are presently underutilized in practice because of the lack of adequate support by existing message-passing libraries and are also rarely considered by parallel algorithm designers. Furthermore, commonly accepted methods for performance analysis and evaluation of parallel systems omit these techniques and focus primarily on more obvious communication characteristics such as latency and bandwidth. This study provides a theoretical framework for describing early binding and overlapping of communication and computation in models for parallel programming. This framework defines four new performance metrics that facilitate new approaches for performance analysis of parallel systems and algorithms. This dissertation provides experimental data that validate the correctness and accuracy of the performance analysis based on the new framework. The theoretical results of this performance analysis can be used by designers of parallel system and application software for assessing the quality of their implementations and for predicting the effective performance benefits of early binding and overlapping. This work presents MPI/Pro, a new MPI implementation that is specifically optimized for clusters of workstations interconnected with high-speed networks. This MPI implementation emphasizes features such as persistent communication, asynchronous processing, low processor overhead, and independent message progress. These features are identified as critical for delivering maximum performance to applications. The experimental section of this dissertation demonstrates the capability of MPI/Pro to facilitate software techniques that result in significant application performance improvements. Specific demonstrations with Virtual Interface Architecture and TCP/IP over Ethernet are offered

    Community-based risk management arrangements : an overview and implications for social fund programs

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    Risk and its consequences pose a formidable threat to poverty reduction efforts. This study reviews a plethora of community-based risk management arrangements across the developing world. These types of arrangements are garnering greater interest in light of the growing recognition of the relative prominence of household or individual-specific idiosyncratic risk as well as the increasing shift towards community-based development funding. The study discusses potential advantages (such as targeting, cost, and informational) and disadvantages (such as exclusion and inability to manage correlated risk) of these arrangements, and their implications for the design of innovative social fund programs.Rural Poverty Reduction,Labor Policies,Insurance&Risk Mitigation,Currencies and Exchange Rates,Debt Markets

    Using Blockchain Technology in Smart Life Applications

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    مقدمة: Blockchain هي قاعدة بيانات يتم تخزينها بترتيب زمني بطريقة آمنة ومستقرة. كانت Bitcoin هي التطبيق الأولي لتقنية Blockchain ، ولكن نظرًا لفوائدها من حيث الأمان والخصوصية والتحكم الذاتي ، فقد تم اعتمادها منذ ذلك الحين من قبل مجموعة متنوعة من التطبيقات. يتم إنشاء تقنية Blockchain عن طريق ربط الكتل معًا بشكل مشفر. نظرًا لأن كل كتلة تحتوي على كلٍ من التجزئة الخاصة بها وتجزئة الكتلة السابقة لها ، فلا يمكن لأي شخص خارجي كسر السلسلة. تُستخدم تقنية Blockchain ضمن مجموعة متنوعة من التطبيقات ، بما في ذلك الصناعية والتجارية والأمنية وسلسلة التوريد وإنترنت الأشياء وغيرها. هذا لأنه يتميز بمزايا التحكم في البيانات وتنظيمها وتخزينها. الغرض من هذه المقالة هو سرد بعض التطبيقات ومجالات التطوير الخاصة بـ Blockchain.   طرق العمل: في تقنية Blockchain ، يعد الأمان والاستقرار (الثبات) واللامركزية من بين الأشياء المهمة التي تجعل هذه التقنية مفيدة في مختلف مجالات الحياة التي تخدم المستخدم. تم استخدام هذه المزايا لحل العديد من المشكلات التي تواجه الشبكة ، بما في ذلك المشكلات المتعلقة بالإنتاجية ووقت المعالجة وقابلية التوسع. تم استخدام طرق مختلفة في الحل ، بما في ذلك العمل على تغيير هيكل الشبكة ، واختيار عقدة أساسية (المدير) ، والتعدين الموازي ، والتنافس مع عمال المناجم الآخرين. الاستنتاجات: ازداد الميل إلى استخدام تقنية Blockchain في العديد من المجالات ، بما في ذلك المالية والزراعية والتجارية والصحية وإنترنت الأشياء وغيرها ، نظرًا لمزاياها ، بما في ذلك اللامركزية والتوزيع والموثوقية والاستقرار. هناك اتجاهات أخرى عملت على تطوير أداء وكفاءة وأمان نظام Blockchain نفسه في إنترنت الأشياء والرعاية الصحية وسلسلة التوريد والقطاع المصرفي والتسويق الرقمي بالإضافة إلى الدراسات التي تشمل تحسين الكفاءة والأمان وتطوير النظام.Background: Materials and Methods:      In Blockchain technology, security, stability (immutability), and decentralization are among the important things that make this technology useful in various areas of life that serve the user. These advantages were used to solve many problems facing the network, including those of productivity, processing time, and scalability. Various methods were used in the solution, including working on a change in the network structure, choosing a basic node (the manager), parallel mining, and competing with other miners. Results:     Through recent studies, it has been shown that the Blockchain technology has been used in various fields, as it is characterized by many advantages, the most important of which are security, decentralization, and stability. Because of these advantages, it outperforms other technologies. Conclusion:     Due to its advantages, the tendency to use blockchain technology has increased in many fields, including financial, agricultural, commercial, health, the Internet of Things, and others. It includes decentralization, distribution, reliability, and stability. There are other trends that have worked to improve the performance, efficiency, and security of the blockchain system itself, In the Internet of Things, healthcare, supply chain management, the banking sector, and digital marketing In addition to studies that include improving the efficiency, security, and development of the system

    Quality of Service and Associated Communication Infrastructure for Electric Vehicles †

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    Transportation electrification is pivotal for achieving energy security and emission reduction goals. Electric vehicles (EVs) are at the forefront of this transition, driving the development of new EV technologies and infrastructure. As this trend gains momentum, it becomes essential to enhance the quality of service (QoS) of EVs to encourage their widespread adoption. This paper has been structured with two primary aims to effectively address the above timely technological needs. Firstly, it comprehensively reviews the various QoS factors that influence EVs’ performance and the user experience. Delving into these factors provides valuable insights into how the QoS can be improved, thereby fostering the increased use of EVs on our roads. In addition to the QoS, this paper also explores recent advancements in communication technologies vital for facilitating in-formation exchanges between EVs and charging stations. Efficient communication systems are crucial for optimizing EV operations and enhancing user experiences. This paper presents expert-level technical details in an easily understandable manner, making it a valuable resource for researchers dedicated to improving the QoS of EV communication systems, who are tirelessly working towards a cleaner, more efficient future in transportation. It consolidates the current knowledge in the field and presents the latest discoveries and developments, offering practical insights for enhancing the QoS in electric transportation. A QoS parameter reference map, a detailed classification of QoS parameters, and a classification of EV communication technology references are some of the key contributions of this review paper. In doing so, this paper contributes to the broader objectives of promoting transportation electrification, enhancing energy security, and reducing emissions
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