2,777 research outputs found

    Ultracompact Generation of Continuous-Variable Cluster States

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    We propose an experimental scheme that has the potential for large-scale realization of continuous-variable (CV) cluster states for universal quantum computation. We do this by mapping CV cluster-state graphs onto two-mode squeezing graphs, which can be engineered into a single optical parametric oscillator (OPO). The desired CV cluster state is produced directly from a joint squeezing operation on the vacuum using a multi-frequency pump beam. This method has potential for ultracompact experimental implementation. As an illustration, we detail an experimental proposal for creating a four-mode square CV cluster state with a single OPO.Comment: 4 pages, 1 figure; v2 improved discussion of the implications of our result; added discussion of finite squeezing effect

    ТЕОСОФИЯ: ГЕНЕЗИС И АКТУАЛИЗАЦИЯ УЧЕНИЯ

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    У статті розглядається сутність теософії в її історико-філософському генезисі, представленому у вченні неоплатоников, гностиків, середньовічних і ренесансних містиків. Визначається сутність теософії як вчення синкретичної єдності ірраціонально-раціонального збагнення глибини реальності. Специфічність теософії розкривається порівняно з філософією, через визначення джерела знання, предмету і методу пізнання. Представлена актуалізація теософії через сучасну діяльність Міжнародного теософського товариства і спадщину О.П.Блаватськой. Вказується натрансформаційні змінимісії теософії, яка з езотеричного вчення переходить в статус морально-етичного корелята розвитку соціальних інститутів іжиттєвого простору людини.В статье рассматривается сущность теософии в её историко-философском генезисе, представленном в учении неоплатоников, гностиков, средневековых и ренессансных мистиков. Определяется сущность теософии как учения синкретического единства иррационально-рационального постижения глубины реальности. Специфичность теософии раскрывается в сравнении с философией, через определение источника знания, предмета и метода познания. Представлена актуализация теософии через современную деятельность Международного теософского общества и наследие Е.П.Блаватской. Указывается на трансформационные изменения миссии теософии, которая из эзотерического учения переходит в статус морально-нравственного коррелята развития социальных институтов и жизненного пространства человека.In the articleessence of theosophy is examined inits historicaland philosophicalgenesis, presented in thestudies of neoplatonizmus, gnostics,medieval andrenaissancemystics. Essence oftheosophy as studies of syncretismunity of the irrational-rational understanding of depth of reality is determined. Specificity of theosophy opens up by comparison to philosophy, through determination of source of knowledge, object andmethod of cognition.Actualization of theosophy is presented throughmodern activity ofInternational theosophicalsociety andlegacy ofE.P.Blavatskoy. Specified on transformation changes themission of theosophywhich fromesoteric studies passes to status ofmoral-moral correlate of development of social institutes and vital space ofman

    Historical vintage descriptions from Luxembourg - an indicator for the climatic conditions in the past?

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    Verbal vintage descriptions in a historical wine chronicle (809-1904) of the Luxembourgish winegrowing region were assigned to five wine quality and three wine quantity classes. To calibrate models describing the impact of the seasonal heat consumption on wine quality and quantity, instrumental records from Luxembourg-City in a reference period (1854-1885) and the associated vintage quality and quantity classes were correlated. Dummy regression models showed, that in the reference period the wine quality classes assigned were significantly correlated with the annual modified heliothermic index values (representing the heat consumption) (R2adj.= 0.55, p = 0.0002); whereas, the incorporation of the wine quantity as additional predictor variable did not significantly improve model output. Based on linear correlations between annual thermal conditions and wine quality descriptions, average April-September temperatures were reconstructed for the period 1200-1904. Running averages calculated using LOESS smoothing showed that periods with cooler and warmer climatic conditions alternated in the past centuries. Even though a precise reconstruction of the annual temperature conditions solely based on vintage descriptions is not possible due to the broad set of potentially interfering effects, long-term climatic trends described in the literature such as the Medieval Climate Optimum and the Little Ice Age could be retrieved

    Rigorous Probabilistic Analysis of Equilibrium Crystal Shapes

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    The rigorous microscopic theory of equilibrium crystal shapes has made enormous progress during the last decade. We review here the main results which have been obtained, both in two and higher dimensions. In particular, we describe how the phenomenological Wulff and Winterbottom constructions can be derived from the microscopic description provided by the equilibrium statistical mechanics of lattice gases. We focus on the main conceptual issues and describe the central ideas of the existing approaches.Comment: To appear in the March 2000 special issue of Journal of Mathematical Physics on Probabilistic Methods in Statistical Physic

    Ice nucleation and cloud microphysical properties in tropical tropopause layer cirrus

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    In past modeling studies, it has generally been assumed that the predominant mechanism for nucleation of ice in the uppermost troposphere is homogeneous freezing of aqueous aerosols. However, recent in situ and remote-sensing measurements of the properties of cirrus clouds at very low temperatures in the tropical tropopause layer (TTL) are broadly inconsistent with theoretial predictions based on the homogeneous freezing assumption. The nearly ubiquitous occurence of gravity waves in the TTL makes the predictions from homogeneous nucleation theory particularly difficult to reconcile with measurements. These measured properties include ice number concentrations, which are much lower than theory predicts; ice crystal size distributions, which are much broader than theory predicts; and cloud extinctions, which are much lower than theory predicts. Although other explanations are possible, one way to limit ice concentrations is to have on the order of 50 L<sup>−1</sup> effective ice nuclei (IN) that could nucleate ice at relatively low supersaturations. We suggest that ammonium sulfate particles, which would be dry much of the time in the cold TTL, are a potential IN candidate for TTL cirrus. However, this mechanism remains to be fully quantified for the size distribution of ammonium sulfate (possibly internally mixed with organics) actually present in the upper troposphere. Possible implications of the observed cloud microphysical properties for ice sedimentation, dehydration, and cloud persistence are also discussed

    Colligative properties of solutions: I. Fixed concentrations

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    Using the formalism of rigorous statistical mechanics, we study the phenomena of phase separation and freezing-point depression upon freezing of solutions. Specifically, we devise an Ising-based model of a solvent-solute system and show that, in the ensemble with a fixed amount of solute, a macroscopic phase separation occurs in an interval of values of the chemical potential of the solvent. The boundaries of the phase separation domain in the phase diagram are characterized and shown to asymptotically agree with the formulas used in heuristic analyses of freezing point depression. The limit of infinitesimal concentrations is described in a subsequent paper.Comment: 28 pages, 1 fig; see also math-ph/0407035 (both to appear in JSP

    Quantum interference of ultrastable twin optical beams

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    We report the first measurement of the quantum phase-difference noise of an ultrastable nondegenerate optical parametric oscillator that emits twin beams classically phase-locked at exact frequency degeneracy. The measurement illustrates the property of a lossless balanced beam-splitter to convert number-difference squeezing into phase-difference squeezing and, thus, provides indirect evidence for Heisenberg-limited interferometry using twin beams. This experiment is a generalization of the Hong-Ou-Mandel interference effect for continuous variables and constitutes a milestone towards continuous-variable entanglement of bright, ultrastable nondegenerate beams.Comment: 4 pages, 4 figs, accepted by Phys. Rev. Let

    Is baryon number violated when electroweak strings intercommute?

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    We reexamine the self-helicity and the intercommutation of electroweak strings. A plausible argument for baryon number conservation when electroweak strings intercommute is presented. The connection between a segment of electroweak strings and a sphaleron is also discussed.Comment: CALT-68-1948, 11 pages, 5 figures available upon request. Replaced with revised version. (Request should be sent to [email protected]

    Modeling and analysis of a deep learning pipeline for cloud based video analytics.

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    Video analytics systems based on deep learning approaches are becoming the basis of many widespread applications including smart cities to aid people and traffic monitoring. These systems necessitate massive amounts of labeled data and training time to perform fine tuning of hyper-parameters for object classification. We propose a cloud based video analytics system built upon an optimally tuned deep learning model to classify objects from video streams. The tuning of the hyper-parameters including learning rate, momentum, activation function and optimization algorithm is optimized through a mathematical model for efficient analysis of video streams. The system is capable of enhancing its own training data by performing transformations including rotation, flip and skew on the input dataset making it more robust and self-adaptive. The use of in-memory distributed training mechanism rapidly incorporates large number of distinguishing features from the training dataset - enabling the system to perform object classification with least human assistance and external support. The validation of the system is performed by means of an object classification case-study using a dataset of 100GB in size comprising of 88,432 video frames on an 8 node cloud. The extensive experimentation reveals an accuracy and precision of 0.97 and 0.96 respectively after a training of 6.8 hours. The system is scalable, robust to classification errors and can be customized for any real-life situation.N/
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