11,776 research outputs found

    Power spectral estimation algorithms

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    Algorithms to estimate the power spectrum using Maximum Entropy Methods were developed. These algorithms were coded in FORTRAN 77 and were implemented on the VAX 780. The important considerations in this analysis are: (1) resolution, i.e., how close in frequency two spectral components can be spaced and still be identified; (2) dynamic range, i.e., how small a spectral peak can be, relative to the largest, and still be observed in the spectra; and (3) variance, i.e., how accurate the estimate of the spectra is to the actual spectra. The application of the algorithms based on Maximum Entropy Methods to a variety of data shows that these criteria are met quite well. Additional work in this direction would help confirm the findings. All of the software developed was turned over to the technical monitor. A copy of a typical program is included. Some of the actual data and graphs used on this data are also included

    Pediatric Rotavirus Gastroenteritis: A 2 year Analysis to Understand Current Prevalence in Mumbai

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    Many studies have established the high prevalence of paediatric Rotavirus gastroenteritis in India. The importance of rapid diagnosis of rotavirus infection has also been stressed upon, to initiate prompt rehydration therapy and prevent unnecessary use of antibiotics .We undertook a retrospective analysis of 327 paediatric stool specimens to understand the current prevalence and seasonal distribution of cases in Mumbai and its surrounding areas. Overall Rotavirus positivity rate was 37.9 %, with peak positivity in winter seasons. Infections were more common upto 2 years of age. Incidence of bacterial and parasitic coinfections was low

    Flutter parametric studies of cantilevered twin-engine transport type wing with and without winglet. Volume 2: Transonic and density effect investigations

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    Flutter characteristics of a cantilevered high aspect ratio wing with winglet were investigated. The configuration represented a current technology, twin engine airplane. Compressibility effects through transonic Mach numbers and a wide range of mass-density ratios were evaluated on a low speed and high speed model. Four flutter mechanisms were obtained from test, and analysis from various combinations of configuration parameters. It is shown that the coupling between wing tip vertical and chordwise motions have significant effect under some conditions. It is concluded that for the flutter model configurations studied, the winglet related flutter is amenable to the conventional flutter analysis techniques. The low speed model flutter and the high-speed model flutter results are described
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