1,798,434 research outputs found

    The quantum Chernoff bound as a measure of distinguishability between density matrices: application to qubit and Gaussian states

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    Hypothesis testing is a fundamental issue in statistical inference and has been a crucial element in the development of information sciences. The Chernoff bound gives the minimal Bayesian error probability when discriminating two hypotheses given a large number of observations. Recently the combined work of Audenaert et al. [Phys. Rev. Lett. 98, 160501] and Nussbaum and Szkola [quant-ph/0607216] has proved the quantum analog of this bound, which applies when the hypotheses correspond to two quantum states. Based on the quantum Chernoff bound, we define a physically meaningful distinguishability measure and its corresponding metric in the space of states; the latter is shown to coincide with the Wigner-Yanase metric. Along the same lines, we define a second, more easily implementable, distinguishability measure based on the error probability of discrimination when the same local measurement is performed on every copy. We study some general properties of these measures, including the probability distribution of density matrices, defined via the volume element induced by the metric, and illustrate their use in the paradigmatic cases of qubits and Gaussian infinite-dimensional states.Comment: 16 page

    Analisa Pengaruh Tingkat Suku Bunga, Inflasi, Kurs, dan Jumlah Uang Beredar terhadap Volume Perdagangan Saham pada Lq-45

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    The capital market is one of investment alternative that able to yield optimal advantage for investor. Each investor is requiring of relevant information with transaction development in stock. This is very important to be made in consideration in compiling strategy and decision making of investment in capital market. The objectives of this research to analyze the influence of interest rate, inflation, exchang rate, and money supply to volume of stock trading on LQ-45 that listed on BEI in 2009-2012 periods.This research using time series data from IDX Statistic ICMD (Indonesian Capital Market Directory) and Indonesian Bank monthly published on BEI in January 2009 until December 2012. Population in this research is all company which included on LQ-45 that is 45 companies and number of samples 16 companies by passing phase purposive sample. Analyze technique to use in this research is multiple linier regression to obtain describe which totally regarding relationship between one variable with other variable. And use aplication Statistical Package For Social Sciences (SPSS) Statistics 21 program. The result of this reseacrh shows that interest rate variable has a negative and not significant to volume of stock trading, while inflation variable has a positive and not significant to volume of stock trading intrading, exchang rate and money supply variable has a negative and significant to volume of stock trading on LQ-45.Result of Adjuts R SquareKeywords : Volume of Stock Trading, Interest Rate, Inflation, Exchange Rates, Broad Mone

    Quasi-hydrostatic X-ray powder diffraction study of the low- and high-pressure phases of CaWO4 up to 28 GPa

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    We have studied CaWO4 under compression using Ne as pressure-transmitting medium at room temperature by means of synchrotron X-ray powder diffraction. We have found that CaWO4 beyond 8.8 GPa transforms from its low-pressure tetragonal structure (scheelite) into a monoclinic structure (fergusonite). The high-pressure phase remains stable up to 28 GPa and the low-pressure phase is totally recovered after full decompression. The pressure dependence of the unit-cell parameters, as well as the pressure volume equation of state, has been determined for both phases. Compared with previous studies, we found in our quasi-hydrostatic experiments a different behavior for the unit-cell parameters of the fergusonite phase and a different transition pressure. These facts suggest that deviatoric stresses influence on the high-pressure structural behavior of CaWO4 as previously found in related compounds. The reported experiments also provide information on the pressure dependence of interatomic bond distances, shedding light on the transition mechanisms. (C) 2014 Elsevier Masson SAS. All rights reserved.Research sponsored by Spanish MINECO (MAT2010-21270-C04-01/04 and CSD2007-00045). Portions of this work were performed at HPCAT (Sector 16), Advanced Photon Source (APS), Argonne National Laboratory. HPCAT operations are supported by DOE-NNSA under Award No. DE-NA0001974 and DOE-BES under Award No. DE-FG02-99ER45775, with partial instrumentation funding by NSF. APS is supported by DOE-BES, under Contract No. DE-AC02-06CH11357.Vilaplana Cerda, RI.; Lacomba-Perales, R.; Gomis, O.; Errandonea, D.; Meng, Y. (2014). Quasi-hydrostatic X-ray powder diffraction study of the low- and high-pressure phases of CaWO4 up to 28 GPa. Solid State Sciences. 36:16-23. https://doi.org/10.1016/j.solidstatesciences.2014.07.003S16233

    From "Periodical Observations” to "Anthochronology” and "Phenology” - the scientific debate between Adolphe Quetelet and Charles Morren on the origin of the word "Phenology”

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    Mankind has observed and documented life cycle stages of plants and animals for a long time. However, it was comparatively recently that the newly emerging science was given its name. The name of Charles Morren and the year 1853 are being cited, although not frequently. Exact information is hardly known among present-day phenologists, yet new evidence shows that the term "phenology” was already in use in 1849. In the early 1840s, physicist and astronomer Adolphe Quetelet set up an observational network named "Observations of periodical Phenomena of the Animal and Vegetable Kingdom” and issued instructions for it. Even though biologist Charles Morren welcomed Quetelet's initiative, differences between Morren and Quentlet regarding the instructions for the observations and the potential results soon arose and a debate started, which lasted for nearly 10years. In the wake of these disagreements, Morren was compelled to create a new term to denote his ideas on "periodical phenomena”. At first, he temporally used the word anthochronology, but in the end he coined the word phenology. The term was first used in a public lecture at the AcadĂ©mie royale des Sciences, des Lettres et des Beaux-Arts de Belgique' in Brussels on 16 December 1849, and simultaneously in the December 1849 issue of volume V of the Annales de la SociĂ©tĂ© royale d'Agriculture et de Botanique de Gand. One had to wait until 1853 before the new name appeared in the title of one of Morren's publications. Based on evidence from archives and original publications, we trace the 10-year-long scientific debate between Morren and Quetelet. Morren states his biologist's view on the subject and extends the more climate-related definition of Quetelet of "periodical phenomena

    Bibliometric studies on single journals: a review

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    This paper covers a total of 82 bibliometric studies on single journals (62 studies cover unique titles) published between 1998 and 2008 grouped into the following fields; Arts, Humanities and Social Sciences (12 items); Medical and Health Sciences (19 items); Sciences and Technology (30 items) and Library and Information Sciences (21 items). Under each field the studies are described in accordance to their geographical location in the following order, United Kingdom, United States and Americana, Europe, Asia (India, Africa and Malaysia). For each study, elements described are (a) the journal’s publication characteristics and indexation information; (b) the objectives; (c) the sampling and bibliometric measures used; and (d) the results observed. A list of journal titles studied is appended. The results show that (a)bibliometric studies cover journals in various fields; (b) there are several revisits of some journals which are considered important; (c) Asian and African contributions is high (41.4 of total studies; 43.5 covering unique titles), United States (30.4 of total; 31.0 on unique titles), Europe (18.2 of total and 14.5 on unique titles) and the United Kingdom (10 of total and 11 on unique titles); (d) a high number of bibliometrists are Indians and as such coverage of Indian journals is high (28 of total studies; 30.6 of unique titles); and (e) the quality of the journals and their importance either nationally or internationally are inferred from their indexation status

    Science on television : how? Like that!

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    This study explores the presence of science programs on the Flemish public broadcaster between 1997 and 2002 in terms of length, science domains, target groups, production mode, and type of broadcast. Our data show that for nearly all variables 2000 can be marked as a year in which the downward spiral for science on television was reversed. These results serve as a case study to discuss the influence of public policy and other possible motives for changes in science programming, as to gain a clearer insight into the factors that influence whether and how science programs are broadcast on television. Three factors were found to be crucial in this respect: 1) public service philosophy, 2) a strong governmental science policy providing structural government support, and 3) the reflection of a social discourse that articulates a need for more hard sciences

    Algorithmic Superactivation of Asymptotic Quantum Capacity of Zero-Capacity Quantum Channels

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    The superactivation of zero-capacity quantum channels makes it possible to use two zero-capacity quantum channels with a positive joint capacity for their output. Currently, we have no theoretical background to describe all possible combinations of superactive zero-capacity channels; hence, there may be many other possible combinations. In practice, to discover such superactive zero-capacity channel-pairs, we must analyze an extremely large set of possible quantum states, channel models, and channel probabilities. There is still no extremely efficient algorithmic tool for this purpose. This paper shows an efficient algorithmical method of finding such combinations. Our method can be a very valuable tool for improving the results of fault-tolerant quantum computation and possible communication techniques over very noisy quantum channels.Comment: 35 pages, 17 figures, Journal-ref: Information Sciences (Elsevier, 2012), presented in part at Quantum Information Processing 2012 (QIP2012), v2: minor changes, v3: published version; Information Sciences, Elsevier, ISSN: 0020-0255; 201

    Brain matters
in social sciences

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    Here we offer a general introduction to cognitive neuroscience and provide examples relevant to psychology, healthcare and bioethics, law and criminology, information studies, of how brain studies have influenced, are influencing or show the potential to influence the social sciences. We argue that social scientists should read, and be enabled to understand, primary sources of evidence in cognitive neuroscience. We encourage cognitive neuroscientists to reflect upon the resonance that their work may have across the social sciences and to facilitate a mutually enriching interdisciplinary dialogue
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