7,989 research outputs found

    Parallel Computing and Localization Techniques for Faster Power System Dynamic Simulations

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    Dynamic simulation studies are used to analyze the behavior of power systems after a disturbance has occurred. This type of simulation is essential when the system is operating close to its stability limits or its behavior is dictated by complex control and protection schemes modifying its trajectory. These simulations can be computationally very demanding, especially if performed over a time interval of several minutes. In this paper, new shared- memory parallel computing techniques to increase the performance of large-scale power system dynamic simulations are described. The algorithms presented achieve this by utilizing the parallel processing resources available in modern, inexpensive, multi-core machines. In addition, the localized response of power systems after a disturbance is exploited to further accelerate simulations without decreasing accuracy. The medium-scale model of a real power system and a realistic large-scale test system have been used for the performance evaluation of the proposed methods.Peer reviewe

    Household screening and multidrug-resistant tuberculosis

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    Of the estimated half a million people who develop multidrug resistant (MDR) tuberculosis each year, less than 7% are diagnosed and only 1 in 5 of these have access to eff ective treatment.1 To control this epidemic, dramatically increased efforts are required to scale up case detection and treatment provision. In The Lancet, Mercedes Becerra and colleagues2 report the yield of additional MDR tuberculosis diagnoses that are found by screening household contacts of index cases in Lima, Peru. This study—the largest of its kind to date—found that more than 2% of 4503 household contacts had active tuberculosis at the time the index case was diagnosed. Incident tuberculosis was also found at a rate of 1624 cases per 100 000 person-years over 4 years follow-up. These results support recommendations for active screening of household contacts of people with MDR tuberculosis,3 and provide valuable lessons for other programmes striving to improve case detection and to reduce community transmission of MDR tuberculosis

    Searching for Plausible N-k Contingencies Endangering Voltage Stability

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