841 research outputs found

    Experimental quantum cryptography scheme based on orthogonal states

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    Since, in general, non-orthogonal states cannot be cloned, any eavesdropping attempt in a Quantum Communication scheme using non-orthogonal states as carriers of information introduces some errors in the transmission, leading to the possibility of detecting the spy. Usually, orthogonal states are not used in Quantum Cryptography schemes since they can be faithfully cloned without altering the transmitted data. Nevertheless, L. Goldberg and L. Vaidman [\prl 75 (1995) 1239] proposed a protocol in which, even if the data exchange is realized using two orthogonal states, any attempt to eavesdrop is detectable by the legal users. In this scheme the orthogonal states are superpositions of two localized wave packets travelling along separate channels. Here we present an experiment realizing this scheme

    Um sistema de compressão de imagens digitais.

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    Este trabalho apresenta o desenvolvimento de um sistema modular e compacto de compressão de imagens digitais. O sistema foi projetado para suportar imagens médicas e de sensoriamento remoto. O problema da diversidade de formatos de imagens é discutido, e a solução encontrada por esse sistema é apresentado

    Mining relevant and extreme patterns on climate time series with CLIPSMiner.

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    One of the most important challenges for the researchers in the 21st Century is related to global heating and climate change that can have as consequence the intensification of natural hazards. Another problem of changes in the Earth's climate is its impact in the agriculture production. In this scenario, application of statistical models as well as development of new methods become very important to aid in the analyses of climate from ground-based stations and outputs of forecasting models. Additionally, remote sensing images have been used to improve the monitoring of crop yields. In this context we propose a new technique to identify extreme values in climate time series and to correlate climate and remote sensing data in order to improve agricultural monitoring. Accordingly, this paper presents a new unsupervised algorithm, called CLIPSMiner (CLImate PatternS Miner) that works on multiple time series of continuous data, identifying relevant patterns or extreme ones according to a relevance factor, which can be tuned by the user. Results show that CLIPSMiner detects, as expected, patterns that are known in climatology, indicating the correctness and feasibility of the proposed algorithm. Moreover, patterns detected using the highest relevance factor is coincident with extreme phenomena. Furthermore, series correlations detected by the algorithm show a relation between agroclimatic and vegetation indices, which confirms the agrometeorologists' expectations

    Melhorando o diagnóstico diferencial entre síndromes mielodisplásicas e citopenias periféricas reativas por citometria de fluxo multiparamétrica: o papel dos precursores de células B

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    Immunophenotyping is a valuable ancillary technique for the differential diagnosis between myelodysplastic syndromes (MDS) with low bone marrow (BM) blast counts and a normal karyotype, and reactive peripheral (PB) cytopenias. Our aim was to search for the most important variables for this purpose. We also analyzed the age variation of BM B-cell precursors (BCP) and its differences in reactive and clonal cytopenias. Immunophenotypic analyzes were performed in BM of 54 patients with MDS (76% with BM blasts 55 years. % BM BCP could be calculated by the formula: (-7.97 × log age) + (4.24 × log % CD34 (+) cells) - (0.22 x nr. alterations CD34 (+) cells) + 0.577. Corrected R(2) = 0.467. Analysis of myelomonocytic precursors and CD34(+) cells was satisfactory for the differential diagnosis between reactive PB cytopenias and MDS. The most specific alterations were found in CD34(+) cells. Comparison of the values obtained with those of normal age-matched controls is recommended. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1975931809154663.Immunophenotyping is a valuable ancillary technique for the differential diagnosis between myelodysplastic syndromes (MDS) with low bone marrow (BM) blast counts and a normal karyotype, and reactive peripheral (PB) cytopenias. Our aim was to search for th104419FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO25924846sem informaçãoFAEPEX (proc 1208/11 Fundo de Pesquisa da Universidade de Campinas) e Fundação MDS (concessão de Jovem Investigador Tito Bastianello 2009). Konradin Metze e Irene Lorand-Metze têm uma bolsa de pesquisa do CNPq (proc. 307270 / 2010-6 e 302277 / 2009-9, re

    Effects of different circuit training protocols on body mass, fat mass and blood parameters among overweight adults

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    The benefits of regular exercise are known for a long time, but the mechanisms underlying the exercise mode recommendations for specific chronic cardiovascular diseases remains unclear. The aim of this study was to evaluate and compare the effects of different circuit training protocols in sedentary overweight adults

    Classificação de áreas de café em Minas Gerais por meio do novo algoritmo QMAS em imagem espectral Geoeye-1.

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    Diante do grande desafio que é classificar imagens de sensoriamento remoto de café, o objetivo deste trabalho foi aplicar o novo algoritmo QMAS para classificar áreas de café comparando os resultados com o método tradicional de Classificação Supervisionada MAXVER, em imagens Geoeye-1. Os resultados indicam que o algoritmo QMAS obteve mais êxito na classificação das áreas de café do que o MAXVER, configurando-se em uma alternativa viável a classificação de imagens de satélite.SBSR 2011

    Complex Network Tools to Understand the Behavior of Criminality in Urban Areas

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    Complex networks are nowadays employed in several applications. Modeling urban street networks is one of them, and in particular to analyze criminal aspects of a city. Several research groups have focused on such application, but until now, there is a lack of a well-defined methodology for employing complex networks in a whole crime analysis process, i.e. from data preparation to a deep analysis of criminal communities. Furthermore, the "toolset" available for those works is not complete enough, also lacking techniques to maintain up-to-date, complete crime datasets and proper assessment measures. In this sense, we propose a threefold methodology for employing complex networks in the detection of highly criminal areas within a city. Our methodology comprises three tasks: (i) Mapping of Urban Crimes; (ii) Criminal Community Identification; and (iii) Crime Analysis. Moreover, it provides a proper set of assessment measures for analyzing intrinsic criminality of communities, especially when considering different crime types. We show our methodology by applying it to a real crime dataset from the city of San Francisco - CA, USA. The results confirm its effectiveness to identify and analyze high criminality areas within a city. Hence, our contributions provide a basis for further developments on complex networks applied to crime analysis.Comment: 7 pages, 2 figures, 14th International Conference on Information Technology : New Generation

    Self consistent, absolute calibration technique for photon number resolving detectors

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    Well characterized photon number resolving detectors are a requirement for many applications ranging from quantum information and quantum metrology to the foundations of quantum mechanics. This prompts the necessity for reliable calibration techniques at the single photon level. In this paper we propose an innovative absolute calibration technique for photon number resolving detectors, using a pulsed heralded photon source based on parametric down conversion. The technique, being absolute, does not require reference standards and is independent upon the performances of the heralding detector. The method provides the results of quantum efficiency for the heralded detector as a function of detected photon numbers. Furthermore, we prove its validity by performing the calibration of a Transition Edge Sensor based detector, a real photon number resolving detector that has recently demonstrated its effectiveness in various quantum information protocols.Comment: 9 pages, 2 figure
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