Poisson Statistics for the Largest Eigenvalues in Random Matrix Ensemble

The paper studies the spectral properties of large Wigner, band and sample covariance random matrices with heavy tails of the marginal distributions of matrix entries.Comment: This is an extended version of my talk at the QMath 9 conference at Giens, France on September 13-17, 200

Supersymmetry approach to Wishart correlation matrices: Exact results

We calculate the `one-point function', meaning the marginal probability density function for any single eigenvalue, of real and complex Wishart correlation matrices. No explicit expression had been obtained for the real case so far. We succeed in doing so by using supersymmetry techniques to express the one-point function of real Wishart correlation matrices as a twofold integral. The result can be viewed as a resummation of a series of Jack polynomials in a non-trivial case. We illustrate our formula by numerical simulations. We also rederive a known expression for the one-point function of complex Wishart correlation matrices.Comment: 21 pages, 2 figure

Track E Implementation Science, Health Systems and Economics

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138412/1/jia218443.pd

Erros de anotações na elaboração de índices de produção em granjas industriais de suínos no Sul do Brasil The human effect on data collection of birth-related production indices in Brazilian swine industrial farms

Foram realizadas observações em quatro granjas de suinocultura industrial nas 24 horas do dia, registrando-se o número de fetos mumificados, de natimortos, de nascidos vivos e total segundo as observações feitas por funcionários da granja (FUN) e por pesquisadores (AO). Foram também registrados resultados de um número semelhante de anotações das mesmas características no período imediatamente anterior à pesquisa, obtidas dos relatórios das granjas. Verificaram-se diferenças entre as avaliações dos FUN e dos AO quanto aos registros dos mumificados e total de nascidos em todas as granjas (P<0,05). A diferença no número de natimortos ocorreu em três granjas (P<0,05) e de nascidos vivos em apenas uma (P<0,05). Os percentuais máximos de mumificados, de natimortos, de nascidos vivos e total não registrados pelos FUN foram 67,8%, 34,5%, 1,8% e 5,1%, respectivamente. Os percentuais máximos das mesmas características não registrados pelos FUN no período imediatamente anterior à pesquisa foram 70,4%, 82,1%, 10,5% e 16,5%.<br>Observational studies were carried out in four industrial swine farms. The observations were performed on a 24 hours basis and mummified fetuses, stillborn and born alive piglets were recorded by observers (OB) and by employees (EM). In all farms, it was also obtained a retrospective data previous to the observational study period, comprising the same number of farrowings. Differences among mummified fetuses and total born piglets recorded by OB and EM in all farms (P<0.05) were observed. The recorded number of stillborn piglets differed between OB and EM in three farms (P<0.05) and the number of born alive piglets in one unit (P<0.05). In all farms during the analysis period, the maximal percentage of recorded mummified fetuses, stillborn, born alive and total born piglets, were 67.8%, 34.5%, 1.8% and 5.1%, respectively. The comparison of retrospective and EM data showed a maximal percentage of not recorded mummified fetuses, stillborn, born alive and total born piglets by EM of 70.4%, 82.1%, 10.5% e 16.5%, respectively. These errors can induce to a wrong interpretation of the farm data and the efforts to maximize the productivity could be directed to other sectors than the farrowing house

Economies of scale in the production of swine manure Economias de escala na produção de dejetos de suínos

Manure production on grower/finisher swine operations in the United States was examined using data from 184 grower/finisher swine operations that participated in the United States National Animal Health Monitoring System's 1995 National Swine Study. Two methods were used: one, assuming that pigs produced 8.4% of their body weight in manure each day; another using the difference between feed fed and weight gained as a proxy variable to study manure production. Using this latter approach, a production function was developed. The function exhibited diminishing returns to scale when food waste was not fed to pigs, but constant returns to scale when food waste was included in their diets. The difference between feed fed and weight gained was lower on operations that restricted entry to employees only.<br>A produção de dejetos em granjas de crescimento e terminação de suínos nos Estados Unidos foi avaliada utilizando dados de 184 granjas participantes de um estudo nacional de 1995 do "United States National Animal Health Monitoring System". Dois métodos foram usados: um considerando que suínos produzem 8,4% do seu peso corporal de dejetos por dia e o outro usando a diferença entre o alimento ingerido e o ganho de peso como um indicador para o estudo da produção de esterco. Através desse último procedimento, desenvolveu-se uma função de produção