7,649 research outputs found

    The compositional construction of Markov processes II

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    In an earlier paper we introduced a notion of Markov automaton, together with parallel operations which permit the compositional description of Markov processes. We illustrated by showing how to describe a system of n dining philosophers, and we observed that Perron-Frobenius theory yields a proof that the probability of reaching deadlock tends to one as the number of steps goes to infinity. In this paper we add sequential operations to the algebra (and the necessary structure to support them). The extra operations permit the description of hierarchical systems, and ones with evolving geometry

    Experimental test of the no signaling theorem

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    In 1981 N. Herbert proposed a gedanken experiment in order to achieve by the ''First Laser Amplified Superluminal Hookup'' (FLASH) a faster than light communication (FTL) by quantum nonlocality. The present work reports the first experimental realization of that proposal by the optical parametric amplification of a single photon belonging to an entangled EPR pair into an output field involving 5 x 10^3 photons. A thorough theoretical and experimental analysis explains in general and conclusive terms the precise reasons for the failure of the FLASH program as well as of any similar FTL proposals.Comment: 4 pages, 4 figure

    Parameterized thermal macromodeling for fast and effective design of electronic components and systems

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    We present a parameterized macromodeling approach to perform fast and effective dynamic thermal simulations of electronic components and systems where key design parameters vary. A decomposition of the frequency-domain data samples of the thermal impedance matrix is proposed to improve the accuracy of the model and reduce the number of the computationally costly thermal simulations needed to build the macromodel. The methodology is successfully applied to analyze the impact of layout variations on the dynamic thermal behavior of a state-of-the-art 8-finger AlGaN/GaN HEMT grown on a SiC substrate

    Visualizing probabilistic models: Intensive Principal Component Analysis

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    Unsupervised learning makes manifest the underlying structure of data without curated training and specific problem definitions. However, the inference of relationships between data points is frustrated by the `curse of dimensionality' in high-dimensions. Inspired by replica theory from statistical mechanics, we consider replicas of the system to tune the dimensionality and take the limit as the number of replicas goes to zero. The result is the intensive embedding, which is not only isometric (preserving local distances) but allows global structure to be more transparently visualized. We develop the Intensive Principal Component Analysis (InPCA) and demonstrate clear improvements in visualizations of the Ising model of magnetic spins, a neural network, and the dark energy cold dark matter ({\Lambda}CDM) model as applied to the Cosmic Microwave Background.Comment: 6 pages, 5 figure

    Contextual, Optimal and Universal Realization of the Quantum Cloning Machine and of the NOT gate

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    A simultaneous realization of the Universal Optimal Quantum Cloning Machine (UOQCM) and of the Universal-NOT gate by a quantum injected optical parametric amplification (QIOPA), is reported. The two processes, forbidden in their exact form for fundamental quantum limitations, are found universal and optimal, and the measured fidelity F<1 is found close to the limit values evaluated by quantum theory. This work may enlighten the yet little explored interconnections of fundamental axiomatic properties within the deep structure of quantum mechanics.Comment: 10 pages, 2 figure

    Finite-size left-passage probability in percolation

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    We obtain an exact finite-size expression for the probability that a percolation hull will touch the boundary, on a strip of finite width. Our calculation is based on the q-deformed Knizhnik--Zamolodchikov approach, and the results are expressed in terms of symplectic characters. In the large size limit, we recover the scaling behaviour predicted by Schramm's left-passage formula. We also derive a general relation between the left-passage probability in the Fortuin--Kasteleyn cluster model and the magnetisation profile in the open XXZ chain with diagonal, complex boundary terms.Comment: 21 pages, 8 figure

    THE POTENTIAL BENEFITS OF ADOPTING THE SINGLE FUEL CONCEPT AT SEA IN THE BRAZILIAN NAVY

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    One of the Brazilian Navy’s critical challenges is monitoring and guarding its extensive Blue Amazon maritime area. Fuel management, which is highly complex and requires the expenditure of significant financial resources, is a fundamental factor for successfully fulfilling naval objectives. Currently, the Brazilian Navy uses diesel to fuel ships and aviation kerosene for aircraft. The purpose of this study is to examine the potential impacts of the Brazilian Navy adopting a single fuel concept (SFC) for its ships in the Blue Amazon protection zone. This concept means using kerosene to fuel both ships and aircraft. We used the Monte Carlo simulation methodology to model and observe the reduction in mission risk due to the SFC implementation in different scenarios. Our results demonstrate a substantial decrease in mission risk from the status quo to the SFC policy, increasing the effectiveness of Brazilian Navy patrol operations. We conclude that the employment of SFC improves the protection of the Blue Amazon’s maritime wealth.Capitao-Tenente, Brazilian NavyCapitão de Corveta, Brazilian NavyApproved for public release. Distribution is unlimited
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