3,043 research outputs found

    The Impact of RDMA on Agreement

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    Remote Direct Memory Access (RDMA) is becoming widely available in data centers. This technology allows a process to directly read and write the memory of a remote host, with a mechanism to control access permissions. In this paper, we study the fundamental power of these capabilities. We consider the well-known problem of achieving consensus despite failures, and find that RDMA can improve the inherent trade-off in distributed computing between failure resilience and performance. Specifically, we show that RDMA allows algorithms that simultaneously achieve high resilience and high performance, while traditional algorithms had to choose one or another. With Byzantine failures, we give an algorithm that only requires n≥2fP+1n \geq 2f_P + 1 processes (where fPf_P is the maximum number of faulty processes) and decides in two (network) delays in common executions. With crash failures, we give an algorithm that only requires n≥fP+1n \geq f_P + 1 processes and also decides in two delays. Both algorithms tolerate a minority of memory failures inherent to RDMA, and they provide safety in asynchronous systems and liveness with standard additional assumptions.Comment: Full version of PODC'19 paper, strengthened broadcast algorith

    Brazilian Payment for Performance (PMAQ) Seen From a Global Health and Public Policy Perspective: What Does it Mean for Research and Policy?

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    This Supplement of the JACM on the Brazilian PMAQ reveals a relevant gap in the Brazilian literature on pay for performance/PMAQ, and is therefore an opportunity to bring contributions from global health and public policy to the debate. We discuss the relevant gap in the light of developments in evaluation and policy analysis. We afterwards present the state of knowledge regarding global health and public policy in pay for performance, giving attention to diverse themes, methods, types of analyses, theoretical contributions and limitations. Finally, we suggest some possible implications for research and policy in Brazil

    Administrative Challenges to the Integration of Oral Health With Primary Care

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    Inadequate access to preventive oral health services contributes to oral health disparities and is a major public health concern in the United States. Federally Qualified Health Centers play a critical role in improving access to care for populations affected by oral health disparities but face a number of administrative challenges associated with implementation of oral health integration models. We conducted a SWOT (strengths, weaknesses, opportunities, and threats) analysis with health care executives to identify strengths, weaknesses, opportunities, and threats of successful oral health integration in Federally Qualified Health Centers. Four themes were identified: (1) culture of health care organizations; (2) operations and administration; (3) finance; and (4) workforce

    SAT Modulo Monotonic Theories

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    We define the concept of a monotonic theory and show how to build efficient SMT (SAT Modulo Theory) solvers, including effective theory propagation and clause learning, for such theories. We present examples showing that monotonic theories arise from many common problems, e.g., graph properties such as reachability, shortest paths, connected components, minimum spanning tree, and max-flow/min-cut, and then demonstrate our framework by building SMT solvers for each of these theories. We apply these solvers to procedural content generation problems, demonstrating major speed-ups over state-of-the-art approaches based on SAT or Answer Set Programming, and easily solving several instances that were previously impractical to solve
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