13,674,734 research outputs found

    Report from U.S. Coalition for Life

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    Summary of The Population Slowdown - A Challenge to the Military by Colonel Robert X. de Marcellus, from a special issue of the The Prolife Reporte

    Theory of Quantum Pulse Position Modulation and Related Numerical Problems

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    The paper deals with quantum pulse position modulation (PPM), both in the absence (pure states) and in the presence (mixed states) of thermal noise, using the Glauber representation of coherent laser radiation. The objective is to find optimal (or suboptimal) measurement operators and to evaluate the corresponding error probability. For PPM, the correct formulation of quantum states is given by the tensorial product of m identical Hilbert spaces, where m is the PPM order. The presence of mixed states, due to thermal noise, generates an optimization problem involving matrices of huge dimensions, which already for 4-PPM, are of the order of ten thousand. To overcome this computational complexity, the currently available methods of quantum detection, which are based on explicit results, convex linear programming and square root measurement, are compared to find the computationally less expensive one. In this paper a fundamental role is played by the geometrically uniform symmetry of the quantum PPM format. The evaluation of error probability confirms the vast superiority of the quantum detection over its classical counterpart.Comment: 10 pages, 7 figures, accepted for publication in IEEE Trans. on Communication

    Clayville Rural Life Center and Museum - Publications Series I - Living History Resource List #05: Metal Trades and Crafts

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    This resource list pertains to the study of metal trades and crafts. The list is divided into two parts: Bibliography and the Conservation and Testing of Metal Artifacts. The Bibliography is further divided into four sections: Primary Production and General; Blacksmithing: Tools, Processes, and Products; Pewter and Pewtersmithing; and Tinware and Tinsmithing. The list contains both primary and secondary sources and their locations. 10p.published or submitted for publicationis peer reviewe

    Clayville Rural Life Center and Museum - Publications Series I - Living History Resource List #12: Inns, Taverns and Hotels in the Midwest to 1860: Materials Useful for the Study of Their Architecture and Functions, and a Checklist of Surviving Buildings in Illinois and in the Midwest

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    This resource list contains sources pertaining to Inns, Taverns, and Hotels in the Midwest to 1860. The publication is divided into three parts: a bibliography, existing structures in Illinois, and existing structures in the Midwest. The bibliography is divided into three parts: the United States, the Midwest, and Illinois. Sources listed include secondary, primary, and archival resources. 14p.published or submitted for publicationis peer reviewe

    On the Stability of Random Multiple Access with Stochastic Energy Harvesting

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    In this paper, we consider the random access of nodes having energy harvesting capability and a battery to store the harvested energy. Each node attempts to transmit the head-of-line packet in the queue if its battery is nonempty. The packet and energy arrivals into the queue and the battery are all modeled as a discrete-time stochastic process. The main contribution of this paper is the exact characterization of the stability region of the packet queues given the energy harvesting rates when a pair of nodes are randomly accessing a common channel having multipacket reception (MPR) capability. The channel with MPR capability is a generalized form of the wireless channel modeling which allows probabilistic receptions of the simultaneously transmitted packets. The results obtained in this paper are fairly general as the cases with unlimited energy for transmissions both with the collision channel and the channel with MPR capability can be derived from ours as special cases. Furthermore, we study the impact of the finiteness of the batteries on the achievable stability region.Comment: The material in this paper was presented in part at the IEEE International Symposium on Information Theory, Saint Petersburg, Russia, Aug. 201

    Subspace Methods for Data Attack on State Estimation: A Data Driven Approach

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    Data attacks on state estimation modify part of system measurements such that the tempered measurements cause incorrect system state estimates. Attack techniques proposed in the literature often require detailed knowledge of system parameters. Such information is difficult to acquire in practice. The subspace methods presented in this paper, on the other hand, learn the system operating subspace from measurements and launch attacks accordingly. Conditions for the existence of an unobservable subspace attack are obtained under the full and partial measurement models. Using the estimated system subspace, two attack strategies are presented. The first strategy aims to affect the system state directly by hiding the attack vector in the system subspace. The second strategy misleads the bad data detection mechanism so that data not under attack are removed. Performance of these attacks are evaluated using the IEEE 14-bus network and the IEEE 118-bus network.Comment: 12 page

    Life of occam-Pi

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    This paper considers some questions prompted by a brief review of the history of computing. Why is programming so hard? Why is concurrency considered an “advanced” subject? What’s the matter with Objects? Where did all the Maths go? In searching for answers, the paper looks at some concerns over fundamental ideas within object orientation (as represented by modern programming languages), before focussing on the concurrency model of communicating processes and its particular expression in the occam family of languages. In that focus, it looks at the history of occam, its underlying philosophy (Ockham’s Razor), its semantic foundation on Hoare’s CSP, its principles of process oriented design and its development over almost three decades into occam-? (which blends in the concurrency dynamics of Milner’s ?-calculus). Also presented will be an urgent need for rationalisation – occam-? is an experiment that has demonstrated significant results, but now needs time to be spent on careful review and implementing the conclusions of that review. Finally, the future is considered. In particular, is there a future
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