13,395 research outputs found

    End-to-end algorithm for hierarchical area searches for long-duration GW sources for GEO 600

    Get PDF
    We describe a hierarchical, highly parallel computer algorithm to perform searches for unknown sources of continuous gravitational waves -- spinning neutron stars in the Galaxy -- over wide areas of the sky and wide frequency bandwidths. We optimize the algorithm for an observing period of 4 months and an available computing power of 20 Gflops, in a search for neutron stars resembling millisecond pulsars. We show that, if we restrict the search to the galactic plane, the method will detect any star whose signal is stronger than 15 times the 1σ1\sigma noise level of a detector over that search period. Since on grounds of confidence the minimum identifiable signal should be about 10 times noise, our algorithm does only 50% worse than this and runs on a computer with achievable processing speed.Comment: 7 pages, for proceedings of Jan 1999 Moriond meeting "Gravitational Waves and Experimental Gravity

    Privacy Implications of Health Information Seeking on the Web

    Full text link
    This article investigates privacy risks to those visiting health- related web pages. The population of pages analyzed is derived from the 50 top search results for 1,986 common diseases. This yielded a total population of 80,124 unique pages which were analyzed for the presence of third-party HTTP requests. 91% of pages were found to make requests to third parties. Investigation of URIs revealed that 70% of HTTP Referer strings contained information exposing specific conditions, treatments, and diseases. This presents a risk to users in the form of personal identification and blind discrimination. An examination of extant government and corporate policies reveals that users are insufficiently protected from such risks

    Creating value(s) by integrating local and extra-local resources in cereal production in the Swiss Alps

    Get PDF
    This paper explores the long-term prospect of alternative, local food initiatives, taking a particular interest in the development of the embedded local values, understood as economic as well as cultural values. Analysing the case of a cooperative of mountain cereal farmers in Switzerland, we show that sustaining local values-based quality is a dynamic process of linking local and extra-local resources. Our results first show the importance of both proximity and place in constructing the ‘local’ by the cooperative. Second, product flow, knowledge and information exchange, quality control, and innovation are governed by both horizontal and vertical relationships between local and extra-local resources, and these multiple relationships build trust in the network and beyond. This, thirdly, enables the cooperative to continuously reproduce its values by weaving them into a cycle of quality creation. We conclude that we need to understand the characteristic values-based quality of the cooperative’s products as the result of a recurring cycle of local and extra-local knowledge creation and resource exchange

    Information technologies for astrophysics circa 2001

    Get PDF
    It is easy to extrapolate current trends to see where technologies relating to information systems in astrophysics and other disciplines will be by the end of the decade. These technologies include mineaturization, multiprocessing, software technology, networking, databases, graphics, pattern computation, and interdisciplinary studies. It is easy to see what limits our current paradigms place on our thinking about technologies that will allow us to understand the laws governing very large systems about which we have large datasets. Three limiting paradigms are saving all the bits collected by instruments or generated by supercomputers; obtaining technology for information compression, storage and retrieval off the shelf; and the linear mode of innovation. We must extend these paradigms to meet our goals for information technology at the end of the decade

    Vision technology/algorithms for space robotics applications

    Get PDF
    The thrust of automation and robotics for space applications has been proposed for increased productivity, improved reliability, increased flexibility, higher safety, and for the performance of automating time-consuming tasks, increasing productivity/performance of crew-accomplished tasks, and performing tasks beyond the capability of the crew. This paper provides a review of efforts currently in progress in the area of robotic vision. Both systems and algorithms are discussed. The evolution of future vision/sensing is projected to include the fusion of multisensors ranging from microwave to optical with multimode capability to include position, attitude, recognition, and motion parameters. The key feature of the overall system design will be small size and weight, fast signal processing, robust algorithms, and accurate parameter determination. These aspects of vision/sensing are also discussed

    Hypersparse Neural Network Analysis of Large-Scale Internet Traffic

    Full text link
    The Internet is transforming our society, necessitating a quantitative understanding of Internet traffic. Our team collects and curates the largest publicly available Internet traffic data containing 50 billion packets. Utilizing a novel hypersparse neural network analysis of "video" streams of this traffic using 10,000 processors in the MIT SuperCloud reveals a new phenomena: the importance of otherwise unseen leaf nodes and isolated links in Internet traffic. Our neural network approach further shows that a two-parameter modified Zipf-Mandelbrot distribution accurately describes a wide variety of source/destination statistics on moving sample windows ranging from 100,000 to 100,000,000 packets over collections that span years and continents. The inferred model parameters distinguish different network streams and the model leaf parameter strongly correlates with the fraction of the traffic in different underlying network topologies. The hypersparse neural network pipeline is highly adaptable and different network statistics and training models can be incorporated with simple changes to the image filter functions.Comment: 11 pages, 10 figures, 3 tables, 60 citations; to appear in IEEE High Performance Extreme Computing (HPEC) 201
    corecore