Physical properties of the Schur complement of local covariance matrices

General properties of global covariance matrices representing bipartite Gaussian states can be decomposed into properties of local covariance matrices and their Schur complements. We demonstrate that given a bipartite Gaussian state $\rho_{12}$ described by a $4\times 4$ covariance matrix \textbf{V}, the Schur complement of a local covariance submatrix $\textbf{V}_1$ of it can be interpreted as a new covariance matrix representing a Gaussian operator of party 1 conditioned to local parity measurements on party 2. The connection with a partial parity measurement over a bipartite quantum state and the determination of the reduced Wigner function is given and an operational process of parity measurement is developed. Generalization of this procedure to a $n$-partite Gaussian state is given and it is demonstrated that the $n-1$ system state conditioned to a partial parity projection is given by a covariance matrix such as its $2 \times 2$ block elements are Schur complements of special local matrices.Comment: 10 pages. Replaced with final published versio

Alternate islands of multiple isochronous chains in wave-particle interactions

We analyze the dynamics of a relativistic particle moving in a uniform magnetic field and perturbed by a standing electrostatic wave. We show that a pulsed wave produces an infinite number of perturbative terms with the same winding number, which may generate islands in the same region of phase space. As a consequence, the number of isochronous island chains varies as a function of the wave parameters. We observe that in all the resonances, the number of chains is related to the amplitude of the various resonant terms. We determine analytically the position of the periodic points and the number of island chains as a function of the wave number and wave period. Such information is very important when one is concerned with regular particle acceleration, since it is necessary to adjust the initial conditions of the particle to obtain the maximum acceleration.Comment: Submitte

Taxa de acúmulo de matéria seca e biomassa aérea de uma pastagem de capim braquiária.

Esse estudo faz parte do projeto de pesquisa denominado "Variabilidade espacial dos índices de qualidade do solo para sistemas agropecuários Qualisolo". O objetivo do estudo é a obtenção da taxa de acúmulo de matéria seca e a biomassa aérea de uma pastagem de capim braquiária usualmente encontrada em propriedades rurais brasileiras de criação de gado de corte. No presente trabalho fez-se também, para efeito de comparação, a estimativa de taxa de acúmulo de matéria seca através de modelos empíricos da literatura que utilizam alguns elementos climáticos. O estudo foi realizado na fazenda experimental do Instituto de Zootecnia, em Nova Odessa (SP), de novembro de 2010 a junho de 2011. A pastagem foi manejada sob pastejo contínuo e taxa de lotação variável. A taxa média de acúmulo da forragem no período foi de 50,5 kg MS. ha?¹.dia?¹ e o acúmulo total de matéria seca em 213 dias foi 10.754,4 kg MS. ha?¹. A análise geoestatística da biomassa obtida em 50 pontos de amostragem revelou dependência espacial somente para a biomassa média dos meses agrupados de verão e outono.bitstream/item/58506/1/001-12.pd

Alterações na cobertura vegetal e no uso das terras entre 1972 e 2009 em área rural do município de Guararapes, SP.

Os produtos de sensoriamento remoto constituem ferramentas importantes para mapeamentos e monitoramentos do uso e da cobertura das terras. O mapeamento do uso e da cobertura das terras em área rural do Município de Guararapes (SP) nos anos de 1972 e 2009 foi realizado por meio de interpretação visual de fotografias aéreas (1972) e de imagens do sensor AVNIR do satélite ALOS (2009). As alterações verificadas entre esses dois anos foram caracterizadas e quantificadas, como subsídio para estudos da dinâmica agropecuária regional e de seus impactos ambientais e socioeconômicos, importantes para ações de planejamento e gestão territorial na região. As pastagens, que cobriam 77% da área de estudo em 1972, foram reduzidas para 45% em 2009, como consequência sobretudo da grande expansão da cultura da cana-de-açúcar

Efficiency of distinct data mining algorithms for classifying stress level in piglets from their vocalization.

ABSTRACT: Among the challenges of pig farming in today's competitive market, there is factor of the product traceability that ensures, among many points, animal welfare. Vocalization is a valuable tool to identify situations of stress in pigs, and it can be used in welfare records for traceability. The objective of this work was to identify stress in piglets using vocalization, calling this stress on three levels: no stress, moderate stress, and acute stress. An experiment was conducted on a commercial farm in the municipality of Holambra, São Paulo State , where vocalizations of twenty piglets were recorded during the castration procedure, and separated into two groups: without anesthesia and local anesthesia with lidocaine base. For the recording of acoustic signals, a unidirectional microphone was connected to a digital recorder, in which signals were digitized at a frequency of 44,100 Hz. For evaluation of sound signals, Praat software was used, and different data mining algorithms were applied using Weka software. The selection of attributes improved model accuracy, and the best attribute selection was used by applying Wrapper method, while the best classification algorithms were the k-NN and Naive Bayes. According to the results, it was possible to classify the level of stress in pigs through their vocalization