79,098 research outputs found

    A Survey of Techniques For Improving Energy Efficiency in Embedded Computing Systems

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    Recent technological advances have greatly improved the performance and features of embedded systems. With the number of just mobile devices now reaching nearly equal to the population of earth, embedded systems have truly become ubiquitous. These trends, however, have also made the task of managing their power consumption extremely challenging. In recent years, several techniques have been proposed to address this issue. In this paper, we survey the techniques for managing power consumption of embedded systems. We discuss the need of power management and provide a classification of the techniques on several important parameters to highlight their similarities and differences. This paper is intended to help the researchers and application-developers in gaining insights into the working of power management techniques and designing even more efficient high-performance embedded systems of tomorrow

    A Review of the Open Educational Resources (OER) Movement: Achievements, Challenges, and New Opportunities

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    Examines the state of the foundation's efforts to improve educational opportunities worldwide through universal access to and use of high-quality academic content

    Global-Scale Resource Survey and Performance Monitoring of Public OGC Web Map Services

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    One of the most widely-implemented service standards provided by the Open Geospatial Consortium (OGC) to the user community is the Web Map Service (WMS). WMS is widely employed globally, but there is limited knowledge of the global distribution, adoption status or the service quality of these online WMS resources. To fill this void, we investigated global WMSs resources and performed distributed performance monitoring of these services. This paper explicates a distributed monitoring framework that was used to monitor 46,296 WMSs continuously for over one year and a crawling method to discover these WMSs. We analyzed server locations, provider types, themes, the spatiotemporal coverage of map layers and the service versions for 41,703 valid WMSs. Furthermore, we appraised the stability and performance of basic operations for 1210 selected WMSs (i.e., GetCapabilities and GetMap). We discuss the major reasons for request errors and performance issues, as well as the relationship between service response times and the spatiotemporal distribution of client monitoring sites. This paper will help service providers, end users and developers of standards to grasp the status of global WMS resources, as well as to understand the adoption status of OGC standards. The conclusions drawn in this paper can benefit geospatial resource discovery, service performance evaluation and guide service performance improvements.Comment: 24 pages; 15 figure

    A Survey of Prediction and Classification Techniques in Multicore Processor Systems

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    In multicore processor systems, being able to accurately predict the future provides new optimization opportunities, which otherwise could not be exploited. For example, an oracle able to predict a certain application\u27s behavior running on a smart phone could direct the power manager to switch to appropriate dynamic voltage and frequency scaling modes that would guarantee minimum levels of desired performance while saving energy consumption and thereby prolonging battery life. Using predictions enables systems to become proactive rather than continue to operate in a reactive manner. This prediction-based proactive approach has become increasingly popular in the design and optimization of integrated circuits and of multicore processor systems. Prediction transforms from simple forecasting to sophisticated machine learning based prediction and classification that learns from existing data, employs data mining, and predicts future behavior. This can be exploited by novel optimization techniques that can span across all layers of the computing stack. In this survey paper, we present a discussion of the most popular techniques on prediction and classification in the general context of computing systems with emphasis on multicore processors. The paper is far from comprehensive, but, it will help the reader interested in employing prediction in optimization of multicore processor systems

    Internet-based 'social sharing' as a new form of global production: The case of SETI@home

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    Benkler ('Sharing Nicely', Yale Law Journal, 2004, Vol. 114, pp. 273-358) has argued that 'social sharing' via Internet-based distributed computing is a new, so far under-appreciated modality of economic production. This paper presents results from an empirical study of SETI@home (the Search for Extraterrestrial Intelligence), which is the classic example of such a computing project. The aim is to explain SETI@home participation and its intensity in a cross-country setting. The data are for a sample of 172 developed and developing countries for the years 2002-2004. The results indicate that SETI@home participation and its intensity can be explained largely by the degree of ICT access (proxied by the International Telecommunication Union's 'Digital Access Index'), as well as GDP per capita and dummy variables for major country groups. Some other variables, such as the Human Development Index, perform less well. Although SETI@home is a global phenomenon, it is never-the-less mostly concentrated in rich countries. However, there are indications of a slowly narrowing global SETI@home digital divide
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