322 research outputs found

    Information security and assurance : Proceedings international conference, ISA 2012, Shanghai China, April 2012

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    Topics in Quantum Metrology, Control, and Communications

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    Noise present in an environment has significant impacts on a quantum system affecting properties like coherence, entanglement and other metrological features of a quantum state. In this dissertation, we address the effects of different types of noise that are present in a communication channel (or medium) and an interferometric setup, and analyze their effects in the contexts of preserving coherence and entanglement, phase sensitivity, and limits on rate of communication through noisy channels. We first consider quantum optical phase estimation in quantum metrology when phase fluctuations are introduced in the system by its interaction with a noisy environment. By considering path-entangled dual-mode photon Fock states in a Mach-Zehnder optical interferometric configuration, we show that such phase fluctuations affect phase sensitivity and visibility by adding noise to the phase to be estimated. We also demonstrate that the optimal detection strategy for estimating a phase in the presence of such phase noise is provided by the parity detection scheme. We then investigate the random birefringent noise present in an optical fiber affecting the coherence properties of a single photon polarization qubit propagating through it. We show that a simple but effective control technique, called dynamical decoupling, can be used to suppress the effects of the dephasing noise, thereby preserving its ability to carry the encoded quantum information in a long-distance optical fiber communication system. Optical amplifiers and attenuators can also add noise to an entangled quantum system, deteriorating the non-classical properties of the state. We show this by considering a two-mode squeezed vacuum state, which is a Gaussian entangled state, propagating through a noisy medium, and characterizing the loss of entanglement in the covariance matrix and the symplectic formalism for this state. Finally, we discuss limits on the rate of communication in the context of sending messages through noisy optical quantum communication channels. In particular, we prove that a strong converse theorem holds under a maximum photon number constraint for these channels, guaranteeing that the success probability in decoding the message vanishes in the asymptotic limit for the rate exceeding the capacity of the channels

    New trends in fibre optic sommunications

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    Přenos optickych vláken je jednou z hlavních metod přenosu informací pro přenos na velké vzdálenosti. Byly vyvinuty různé modulační formáty pro maximalizaci informací přenášenych prostřednictvím komunikačního kanálu. Takové formáty sahají od formátů, které přenášejí jeden bit na symbol (jako je například binární fázové posunování klíčů, BPSK), a nebo vice, jako je například Kvadraturní fázové posunovací klíčování, duální polarizační kvadraturní fázové řazení a mnoho dalších ostatní modulace. Cílem diplomové práce je vytvořit a implementovat přenosovy systém s rychlostí 100 Gbps pomocí modulace formátu DP QPSK. Vysledky jsou shrnuty s ohledem na to, co bylo úspěšně implementováno, a zlepšení, která mohou byt ještě učiněna pro zvyšení přenosové vzdálenosti a snížení BER mimo jiné. Použitysimulační software je PHOTOSS.Optical fiber transmission is one of the leading methods of information transfer for long distance transmission. Various modulation formats have been developed to maximize information transferred through a communication channel. Such formats range from those that transfer one bit per symbol (such as Binary Phase Shift Keying, BPSK), or Quadrature Phase Shift Keying, 3 bits such as in 4 bits per symbol such as Dual Polarization Quadrature Phase Shift Keying and many other modulations. The goal of this thesis is to create and implement a 100 Gbps transmission system using DP QPSK modulation format. The results are discussed with respect to what was successfully implemented and improvements that can still be made to enhance the transmission distance and reduce BER among others. The simulation software used is PHOTOSS.

    System engineering for radio frequency communication consolidation with parabolic antenna stacking

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    2020 Fall.Includes bibliographical references.This dissertation implements System Engineering (SE) practices while utilizing Model Based System Engineering (MBSE) methods through software applications for the design and development of a parabolic stacked antenna. Parabolic antenna stacking provides communication system consolidation by having multiple antennas on a single pedestal which reduces the number of U.S. Navy shipboard topside antennas. The dissertation begins with defining early phase system lifecycle processes and the correlation of these early processes to activities performed when the system is being developed. Performing SE practices with the assistance of MBSE, Agile, Lean methodologies and SE / engineering software applications reduces the likelihood of system failure, rework, schedule delays, and cost overruns. Using this approach, antenna system consolidation via parabolic antenna stacking is investigated while applying SE principles and utilizing SE software applications. SE / engineering software such as IBM Rational Software, Innoslate, Antenna Magus, ExtendSim, and CST Microwave Studio were used to perform SE activities denoted in ISO, IEC, and IEEE standards. A method to achieve multi-band capabilities on a single antenna pedestal in order to reduce the amount of U.S. Navy topside antennas is researched. An innovative approach of parabolic antenna stacking is presented to reduce the amount of antennas that take up physical space on shipboard platforms. Process simulation is presented to provide an approach to improve predicting delay times for operational availability measures and to identify process improvements through lean methodologies. Finally, this work concludes with a summary and suggestions for future work

    30th International Conference on Condition Monitoring and Diagnostic Engineering Management (COMADEM 2017)

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    Proceedings of COMADEM 201

    1992 NASA/ASEE Summer Faculty Fellowship Program

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    For the 28th consecutive year, a NASA/ASEE Summer Faculty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The program was conducted by the University of Alabama and MSFC during the period June 1, 1992 through August 7, 1992. Operated under the auspices of the American Society for Engineering Education, the MSFC program, was well as those at other centers, was sponsored by the Office of Educational Affairs, NASA Headquarters, Washington, DC. The basic objectives of the programs, which are the 29th year of operation nationally, are (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate and exchange ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA centers

    ESSE 2017. Proceedings of the International Conference on Environmental Science and Sustainable Energy

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    Environmental science is an interdisciplinary academic field that integrates physical-, biological-, and information sciences to study and solve environmental problems. ESSE - The International Conference on Environmental Science and Sustainable Energy provides a platform for experts, professionals, and researchers to share updated information and stimulate the communication with each other. In 2017 it was held in Suzhou, China June 23-25, 2017

    HPCCP/CAS Workshop Proceedings 1998

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    This publication is a collection of extended abstracts of presentations given at the HPCCP/CAS (High Performance Computing and Communications Program/Computational Aerosciences Project) Workshop held on August 24-26, 1998, at NASA Ames Research Center, Moffett Field, California. The objective of the Workshop was to bring together the aerospace high performance computing community, consisting of airframe and propulsion companies, independent software vendors, university researchers, and government scientists and engineers. The Workshop was sponsored by the HPCCP Office at NASA Ames Research Center. The Workshop consisted of over 40 presentations, including an overview of NASA's High Performance Computing and Communications Program and the Computational Aerosciences Project; ten sessions of papers representative of the high performance computing research conducted within the Program by the aerospace industry, academia, NASA, and other government laboratories; two panel sessions; and a special presentation by Mr. James Bailey

    A survey of the application of soft computing to investment and financial trading

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    Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau, 8 - 12 September 2014 ; programme

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    Druckausgabe erschienen im Universitätsverlag Ilmenau: Shaping the future by engineering : 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau, 8 - 12 September 2014 ; programme / Department of Mechanical Engineering, Technische Universität Ilmenau. [Hrsg.: Peter Scharff. Red.: Andrea Schneider] Ilmenau : Univ.-Verl. Ilmenau, 2014. - 155 S. ISBN 978-3-86360-085-
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