The domain of a global function is the set of all global states of an execution of a distributed program, We show how to monitor a program in order to determine if there exists a global state in which the sum x(1) + x...
The domain of a global function is the set of all global states of an execution of a distributed program, We show how to monitor a program in order to determine if there exists a global state in which the sum x(1) + x(2) +...+ x(N), exceeds some constant K, where x(i) is defined in process i. We examine the cases where x(i) is an integer variable for N = 2 and where x(i) is a boolean variable for general N, For both cases we provide algorithms, prove their correctness, and analyze their complexity. (C) 1997 Academic Press.
Aero engine blade structure is prone to severe fretting wear under centrifugal forces and vibration loads, resulting in greatly reduced engine service life, which is a typical fretting damage problem. In this paper, w...
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Aero engine blade structure is prone to severe fretting wear under centrifugal forces and vibration loads, resulting in greatly reduced engine service life, which is a typical fretting damage problem. In this paper, without Absorbing layer Nanosecond Laser Shock Peening (wAN-LSP) and without Absorbing layer Nanosecond superimposed Femtosecond hybrid Laser Shock Peening (NF-LSP) are utilized to strengthen the surface of GH4169 dovetail joint specimens, which is a common material for engine blades, to explore its strengthening mechanism and fretting wear evolution law. The findings indicate that the surface roughness of the wAN-LSP specimen rises from 0.28 μm to 1.16 μm. The thermal effects of wAN-LSP lead to the formation of a molten layer roughly 10.97 μm thick on the surface, accompanied by numerous pits, ablation holes, and micro-cracks. In contrast, NF-LSP treatment effectively eliminates the surface oxidation defects made by the thermal effects of wAN-LSP, leading to a slight decrease in surface roughness. Both wAN-LSP and NF-LSP treatments enhance the surface hardness of the specimens, creating a plastic deformation layer roughly 400 μm deep, but the near surface hardness of NF-LSP treated specimen is further improved compared to that of the wAN-LSP specimen. The wear mechanism observed in the GH4169 dovetail joint specimens following wAN-LSP and NF-LSP treatment are identified as abrasive wear and oxidation wear. Initially, as the number of cycles raises, the wear volume of GH4169 specimen treated with wAN-LSP is higher than that of untreated specimen, but subsequently, it becomes lesser than that of the untreated specimen. This phenomenon results from the interplay between the molten layer and hardened layer. In the initial stage of wear, despite the surface strengthening of the wAN-LSP specimen, the presence of molten layer significantly diminishes the fretting wear resistance of the material. As wear progresses, the molten layer is removed, revealing the be
With the immense computing power at our disposal, the numerical solution of partial differential equations (PDEs) is becoming a day-to-day task for modern computational scientists. However, the complexity of real-life...
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The decay of jellyfish blooms introduces a significant organic matter source to the local marine environment that has still an unknown impact on the ecosystem. In recent laboratory experiments, authors studied how the...
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Fluids in computational hydrodynamics are often considered Newtonian, meaning a constant viscosity, but that is just a crude approximation for many real-world examples. Accounting for Non-Newtonian behaviour can provi...
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A system for specification and proof of distributed programs is presented. The method is based directly on the partial order of local states (poset) and avoids the notions of time and simultaneity. Programs are specif...
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A system for specification and proof of distributed programs is presented. The method is based directly on the partial order of local states (poset) and avoids the notions of time and simultaneity. Programs are specified by documenting the relationship between local states which are adjacent to each other in the poset. Program properties are defined by stating properties of the poset. Many program properties can be expressed succinctly and elegantly using this method because poset properties inherently account for varying processor execution speeds. The system utilizes a proof technique which uses induction on the complement of the causally precedes relation and is shown to be useful in proving poset properties. We demonstrate the system on three example algorithms: vector clocks, mutual exclusion, and direct dependency clocks.
Communication and coordination between OSS developers who do not work physically in the same location have always been the challenging *** pull-based development model,as the state-of-art collaborative development mec...
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Communication and coordination between OSS developers who do not work physically in the same location have always been the challenging *** pull-based development model,as the state-of-art collaborative development mechanism,provides high openness and transparency to improve the visibility of contributors'***,duplicate contributions may still be submitted by more than one contributors to solve the same problem due to the parallel and uncoordinated nature of this *** not detected in time,duplicate pull-requests can cause contributors and reviewers to waste time and energy on redundant *** this paper,we propose an approach combining textual and change similarities to automatically detect duplicate contributions in pull-based model at submission *** a new-arriving contribution,we first compute textual similarity and change similarity between it and other existing *** then our method returns a list of candidate duplicate contributions that are most similar with the new contribution in terms of the combined textual and change *** evaluation shows that 83.4%of the duplicates can be found in average when we use the combined textual and change similarity compared to 54.8%using only textual similarity and 78.2%using only change similarity.
Serialization and deserialization play a dominant role in the state transfer time of serverless workflows, leading to substantial performance penalties during workflow execution. We identify the key reason as a lack o...
Natural graphs with skewed distribution raise unique challenges to graph computation and partitioning. Existing graph-parallelsystems usually use a "one size fits all" design that uniformly processes all ve...
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