180 research outputs found

    Design, development and evaluation of the ruggedized edge computing node (RECON)

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    The increased quality and quantity of sensors provide an ever-increasing capability to collect large quantities of high-quality data in the field. Research devoted to translating that data is progressing rapidly; however, translating field data into usable information can require high performance computing capabilities. While high performance computing (HPC) resources are available in centralized facilities, bandwidth, latency, security and other limitations inherent to edge location in field sensor applications may prevent HPC resources from being used in a timely fashion necessary for potential United States Army Corps of Engineers (USACE) field applications. To address these limitations, the design requirements for RECON are established and derived from a review of edge computing, in order to develop and evaluate a novel high-power, field-deployable HPC platform capable of operating in austere environments at the edge

    The Ledger and Times, May 31, 1968

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    Smallholder pig value chain development in Vietnam: Situation analysis and trends

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    The Ledger and Times, May 31, 1968

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    The Ledger and Times, May 31, 1968

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    NASA Tech Briefs, February 1991

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    Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

    Runtime Management of Multiprocessor Systems for Fault Tolerance, Energy Efficiency and Load Balancing

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    Efficiency of modern multiprocessor systems is hurt by unpredictable events: aging causes permanent faults that disable components; application spawnings and terminations taking place at arbitrary times, affect energy proportionality, causing energy waste; load imbalances reduce resource utilization, penalizing performance. This thesis demonstrates how runtime management can mitigate the negative effects of unpredictable events, making decisions guided by a combination of static information known in advance and parameters that only become known at runtime. We propose techniques for three different objectives: graceful degradation of aging-prone systems; energy efficiency of heterogeneous adaptive systems; and load balancing by means of work stealing. Managing aging-prone systems for graceful efficiency degradation, is based on a high-level system description that encapsulates hardware reconfigurability and workload flexibility and allows to quantify system efficiency and use it as an objective function. Different custom heuristics, as well as simulated annealing and a genetic algorithm are proposed to optimize this objective function as a response to component failures. Custom heuristics are one to two orders of magnitude faster, provide better efficiency for the first 20% of system lifetime and are less than 13% worse than a genetic algorithm at the end of this lifetime. Custom heuristics occasionally fail to satisfy reconfiguration cost constraints. As all algorithms\u27 execution time scales well with respect to system size, a genetic algorithm can be used as backup in these cases. Managing heterogeneous multiprocessors capable of Dynamic Voltage and Frequency Scaling is based on a model that accurately predicts performance and power: performance is predicted by combining static, application-specific profiling information and dynamic, runtime performance monitoring data; power is predicted using the aforementioned performance estimations and a set of platform-specific, static parameters, determined only once and used for every application mix. Three runtime heuristics are proposed, that make use of this model to perform partial search of the configuration space, evaluating a small set of configurations and selecting the best one. When best-effort performance is adequate, the proposed approach achieves 3% higher energy efficiency compared to the powersave governor and 2x better compared to the interactive and ondemand governors. When individual applications\u27 performance requirements are considered, the proposed approach is able to satisfy them, giving away 18% of system\u27s energy efficiency compared to the powersave, which however misses the performance targets by 23%; at the same time, the proposed approach maintains an efficiency advantage of about 55% compared to the other governors, which also satisfy the requirements. Lastly, to improve load balancing of multiprocessors, a partial and approximate view of the current load distribution among system cores is proposed, which consists of lightweight data structures and is maintained by each core through cheap operations. A runtime algorithm is developed, using this view whenever a core becomes idle, to perform victim core selection for work stealing, also considering system topology and memory hierarchy. Among 12 diverse imbalanced workloads, the proposed approach achieves better performance than random, hierarchical and local stealing for six workloads. Furthermore, it is at most 8% slower among the other six workloads, while competing strategies incur a penalty of at least 89% on some workload

    Some problems of designing for augmentative and alternative communication users: an enquiry through practical design activity

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    The submission is concerned with, and addresses, problems of designing for people with disabilities, with specific reference to people who are illiterate and cannot speak. People with such disabilities often depend on electronic AAC (Augmentative and Alternative Communication) devices for interpersonal communication. A central theme of the thesis, however, is that such products, and products intended for people with disabilities more generally, have characteristics that inadequately attend to users' needs. Through a combination of practical product development and literature reviews, the thesis demonstrates how improvements to AAC devices 'can be made through user-participatory, usercentred and more sensitive and perceptive design. Literature reviews in the following subjects are reported: AAC; the operational knowledge base for design and disability; user participatory design; and wearable computing. At the core of the thesis is the presentation and discussion of an empirical case study, carried out by the researcher, to design and develop the Portland Communication Aid (PCA). The PCA was conceived as an AAC product that would attempt to redress the inadequacies of predecessor devices. The design activity for the PCA is traced in the thesis, from initial concepts and development models through to a working prototype. Key ideas and essential principles of the design are illustrated. Throughout the work on the PCA, many problems associated with designing for people with severe communication disabilities were encountered. These problems, as with their resolutions, comprised matters of both designing (as an activity) and design (as product specification). The thesis contains comprehensive exposure and analysis of these problems and resolutions. In particular, the value of shaping meaning, metaphor, and other product semantics into devices intended for use by people with disabilities is explored. The study provides two substantive conclusions. First, that both the activity and the outcomes of Industrial Design have a valuable role in the empowerment and rehabilitation of AAC users. And second, that key principles have been identified that will enable designers to better identify, articulate and respond to the needs of people with communication disabilities (and the needs of people with disabilities more generally

    Trustworthy Knowledge Planes For Federated Distributed Systems

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    In federated distributed systems, such as the Internet and the public cloud, the constituent systems can differ in their configuration and provisioning, resulting in significant impacts on the performance, robustness, and security of applications. Yet these systems lack support for distinguishing such characteristics, resulting in uninformed service selection and poor inter-operator coordination. This thesis presents the design and implementation of a trustworthy knowledge plane that can determine such characteristics about autonomous networks on the Internet. A knowledge plane collects the state of network devices and participants. Using this state, applications infer whether a network possesses some characteristic of interest. The knowledge plane uses attestation to attribute state descriptions to the principals that generated them, thereby making the results of inference more trustworthy. Trustworthy knowledge planes enable applications to establish stronger assumptions about their network operating environment, resulting in improved robustness and reduced deployment barriers. We have prototyped the knowledge plane and associated devices. Experience with deploying analyses over production networks demonstrate that knowledge planes impose low cost and can scale to support Internet-scale networks

    Trustworthy Knowledge Planes For Federated Distributed Systems

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    In federated distributed systems, such as the Internet and the public cloud, the constituent systems can differ in their configuration and provisioning, resulting in significant impacts on the performance, robustness, and security of applications. Yet these systems lack support for distinguishing such characteristics, resulting in uninformed service selection and poor inter-operator coordination. This thesis presents the design and implementation of a trustworthy knowledge plane that can determine such characteristics about autonomous networks on the Internet. A knowledge plane collects the state of network devices and participants. Using this state, applications infer whether a network possesses some characteristic of interest. The knowledge plane uses attestation to attribute state descriptions to the principals that generated them, thereby making the results of inference more trustworthy. Trustworthy knowledge planes enable applications to establish stronger assumptions about their network operating environment, resulting in improved robustness and reduced deployment barriers. We have prototyped the knowledge plane and associated devices. Experience with deploying analyses over production networks demonstrate that knowledge planes impose low cost and can scale to support Internet-scale networks
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