681 research outputs found

    Transmission of continuous query results in mobile computing systems

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    Cataloged from PDF version of article.In a mobile computing environment, a user with a wireless connection to the information network can access data via submitting queries to data servers. As the mobility is the most distinguishing feature of the mobile computing paradigm, location becomes an important piece of information for the so-called location-dependent queries, where the answer to a query depends on the current location of the user who issued the query. A location-dependent query submitted by a mobile user can become more difficult to process when it is submitted as a continuous query (CQ) for which the answer changes as the user moves. The answer to a location-dependent CQ can be provided as a set of tuples [S, begin, end] indicating that object S is the answer of the query from time begin to time end. Once the tuples in the answer set are determined, the next step is to determine the transmission time of these tuples to the user. Transmission time of tuples is critical in the sense that it can have a considerable impact on both the communication overhead imposed on the wireless network and the availability of tuples in case of disconnections. In this paper, we propose three tuple transmission approaches that can be used to determine the transmission time of tuples in the answer set of a location-dependent CQ. We also evaluate the relative performance of the proposed approaches under different settings of environmental parameters. (C) 2000 Elsevier Science Inc. All rights reserved

    A duality approach to the fractional Laplacian with measure data

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    We describe a duality method to prove both existence and uniqueness of solutions to nonlocal problems like (-∆)s ʋ = µ in RN with vanishing conditions at inffnity. Here if is a bounded Radon measure whose support is compactly contained in RN N ≥ 2, and - (∆)s is the fractional Laplace operator of order s ϵ (1/2,1)

    Full-complex amplitude modulation with binary spatial light modulators

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    Cataloged from PDF version of article.Imperfections and nonrobust behavior of practical multilevel spatial light modulators (SLMs) degrade the performance of many proposed full-complex amplitude modulation schemes. We consider the use of more robust binary SLMs for this purpose. We propose a generic method, by which, out of K binary (or 1 bit) SLMs of size M × N, we effectively create a new 2K -level (or K bit) SLM of size M × N. The method is a generalization of the well-known concepts of bit plane representation and decomposition for ordinary gray scale digital images and relies on forming a properly weighted superposition of binary SLMs. When K is sufficiently large, the effective SLM can be regarded as a full-complex one. Our method is as efficient as possible from an information theoretical perspective. A 4f system is discussed as a possible optical implementation. This 4f system also provides a means for eliminating the undesirable higher diffraction orders. The components of the 4f system can easily be customized for different production technologies. © 2011 Optical Society of Americ

    Bilvideo-7: an MPEG-7- compatible video indexing and retrieval system

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    Cataloged from PDF version of article.BilVideo-7 is an MPEG-7-compatible, distributed, video indexing and retrieval system that supports complex multimodal queries in a unified framework

    Yönetim teknolojileri ve insan kaynakları

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    İmalat sanayiinde gözlenen yönetim teknolojileri ve insan kaynaklarına ilişkin uygulamalardan bahsetmektedir

    Üretim sistemleri teknolojileri

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    İmalat sektöründe kullanılan üretim sistemleri teknolojilerinin yaygınlığı incelenmektedir
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