3,650 research outputs found

    GPU Resource Optimization and Scheduling for Shared Execution Environments

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    General purpose graphics processing units have become a computing workhorse for a variety of data- and compute-intensive applications, from large supercomputing systems for massive data analytics to small, mobile embedded devices for autonomous vehicles. Making effective and efficient use of these processors traditionally relies on extensive programmer expertise to design and develop kernel methods which simultaneously trade off task decomposition and resource exploitation. Often, new architecture designs force code refinements in order to continue to achieve optimal performance. At the same time, not all applications require full utilization of the system to achieve that optimal performance. In this case, the increased capability of new architectures introduces an ever-widening gap between the level of resources necessary for optimal performance and the level necessary to maintain system efficiency. The ability to schedule and execute multiple independent tasks on a GPU, known generally as concurrent kernel execution, enables application programmers and system developers to balance application performance and system efficiency. Various approaches to develop both coarse- and fine-grained scheduling mechanisms to achieve a high degree of resource utilization and improved application performance have been studied. Most of these works focus on mechanisms for the management of compute resources, while a small percentage consider the data transfer channels. In this dissertation, we propose a pragmatic approach to scheduling and managing both types of resources – data transfer and compute – that is transparent to an application programmer and capable of providing near-optimal system performance. Furthermore, the approaches described herein rely on reinforcement learning methods, which enable the scheduling solutions to be flexible to a variety of factors, such as transient application behaviors, changing system designs, and tunable objective functions. Finally, we describe a framework for the practical implementation of learned scheduling policies to achieve high resource utilization and efficient system performance

    Virtue integrated platform : holistic support for distributed ship hydrodynamic design

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    Ship hydrodynamic design today is often still done in a sequential approach. Tools used for the different aspects of CFD (Computational Fluid Dynamics) simulation (e.g. wave resistance, cavitation, seakeeping, and manoeuvring), and even for the different levels of detail within a single aspect, are often poorly integrated. VIRTUE (the VIRtual Tank Utility in Europe) project has the objective to develop a platform that will enable various distributed CFD and design applications to be integrated so that they may operate in a unified and holistic manner. This paper presents an overview of the VIRTUE Integrated Platform (VIP), e.g. research background, objectives, current work, user requirements, system architecture, its implementation, evaluation, and current development and future work

    Weiterentwicklung analytischer Datenbanksysteme

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    This thesis contributes to the state of the art in analytical database systems. First, we identify and explore extensions to better support analytics on event streams. Second, we propose a novel polygon index to enable efficient geospatial data processing in main memory. Third, we contribute a new deep learning approach to cardinality estimation, which is the core problem in cost-based query optimization.Diese Arbeit trägt zum aktuellen Forschungsstand von analytischen Datenbanksystemen bei. Wir identifizieren und explorieren Erweiterungen um Analysen auf Eventströmen besser zu unterstützen. Wir stellen eine neue Indexstruktur für Polygone vor, die eine effiziente Verarbeitung von Geodaten im Hauptspeicher ermöglicht. Zudem präsentieren wir einen neuen Ansatz für Kardinalitätsschätzungen mittels maschinellen Lernens

    Bio-inspired computation: where we stand and what's next

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    In recent years, the research community has witnessed an explosion of literature dealing with the adaptation of behavioral patterns and social phenomena observed in nature towards efficiently solving complex computational tasks. This trend has been especially dramatic in what relates to optimization problems, mainly due to the unprecedented complexity of problem instances, arising from a diverse spectrum of domains such as transportation, logistics, energy, climate, social networks, health and industry 4.0, among many others. Notwithstanding this upsurge of activity, research in this vibrant topic should be steered towards certain areas that, despite their eventual value and impact on the field of bio-inspired computation, still remain insufficiently explored to date. The main purpose of this paper is to outline the state of the art and to identify open challenges concerning the most relevant areas within bio-inspired optimization. An analysis and discussion are also carried out over the general trajectory followed in recent years by the community working in this field, thereby highlighting the need for reaching a consensus and joining forces towards achieving valuable insights into the understanding of this family of optimization techniques

    Bio-inspired computation: where we stand and what's next

    Get PDF
    In recent years, the research community has witnessed an explosion of literature dealing with the adaptation of behavioral patterns and social phenomena observed in nature towards efficiently solving complex computational tasks. This trend has been especially dramatic in what relates to optimization problems, mainly due to the unprecedented complexity of problem instances, arising from a diverse spectrum of domains such as transportation, logistics, energy, climate, social networks, health and industry 4.0, among many others. Notwithstanding this upsurge of activity, research in this vibrant topic should be steered towards certain areas that, despite their eventual value and impact on the field of bio-inspired computation, still remain insufficiently explored to date. The main purpose of this paper is to outline the state of the art and to identify open challenges concerning the most relevant areas within bio-inspired optimization. An analysis and discussion are also carried out over the general trajectory followed in recent years by the community working in this field, thereby highlighting the need for reaching a consensus and joining forces towards achieving valuable insights into the understanding of this family of optimization techniques

    Provably-Efficient and Internally-Deterministic Parallel Union-Find

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    Determining the degree of inherent parallelism in classical sequential algorithms and leveraging it for fast parallel execution is a key topic in parallel computing, and detailed analyses are known for a wide range of classical algorithms. In this paper, we perform the first such analysis for the fundamental Union-Find problem, in which we are given a graph as a sequence of edges, and must maintain its connectivity structure under edge additions. We prove that classic sequential algorithms for this problem are well-parallelizable under reasonable assumptions, addressing a conjecture by [Blelloch, 2017]. More precisely, we show via a new potential argument that, under uniform random edge ordering, parallel union-find operations are unlikely to interfere: TT concurrent threads processing the graph in parallel will encounter memory contention O(T2logVlogE)O(T^2 \cdot \log |V| \cdot \log |E|) times in expectation, where E|E| and V|V| are the number of edges and nodes in the graph, respectively. We leverage this result to design a new parallel Union-Find algorithm that is both internally deterministic, i.e., its results are guaranteed to match those of a sequential execution, but also work-efficient and scalable, as long as the number of threads TT is O(E13ε)O(|E|^{\frac{1}{3} - \varepsilon}), for an arbitrarily small constant ε>0\varepsilon > 0, which holds for most large real-world graphs. We present lower bounds which show that our analysis is close to optimal, and experimental results suggesting that the performance cost of internal determinism is limited

    How Is a Moving Target Continuously Tracked Behind Occluding Cover?

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    Office of Naval Research (N00014-95-1-0657, N00014-95-1-0409

    Aerospace medicine and biology: A continuing bibliography with indexes, supplement 204

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    This bibliography lists 140 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1980
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