The Experts below are selected from a list of 73203 Experts worldwide ranked by ideXlab platform
Jaewoo Chang - One of the best experts on this subject based on the ideXlab platform.
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hilbert curve based cryptographic Transformation scheme for Spatial query processing on outsourced private data
Data and Knowledge Engineering, 2016Co-Authors: Hyeongil Kim, Seungtae Hong, Jaewoo ChangAbstract:Research on preserving location data privacy in outsourced databases has been spotlighted with the development of cloud computing. However, the existing Spatial Transformation schemes are vulnerable to various attack models. The existing cryptographic Transformation scheme provides good data privacy, but it has a high query processing cost. To improve privacy and reduce cost, we propose a Hilbert curve-based cryptographic Transformation scheme to preserve the privacy of the Spatial data from various attacks on outsourced databases. We also provide efficient range and k-NN query processing algorithms using a Hilbert-order index. A performance analysis confirms that the proposed scheme is robust against attack models and achieves better query processing performance than the existing cryptographic Transformation scheme.
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hilbert curve based cryptographic Transformation scheme for protecting data privacy on outsourced private Spatial data
International Conference on Big Data and Smart Computing, 2014Co-Authors: Hyeongil Kim, Seungtae Hong, Jaewoo ChangAbstract:The study on Spatial database outsourcing has been spotlighted with the development of cloud computing. Therefore, researches for protecting location data privacy in outsourced database have been studied. However, the existing Spatial Transformation schemes are vulnerable to naive attack models. The existing cryptographic Transformation scheme provides high data privacy, but it causes the high query processing cost. To solve these problems, in this paper we propose a Hilbert-curve based cryptographic Transformation scheme to protect data privacy and to improve the efficiency of the query processing in outsourced databases. The proposed scheme reduces the communication cost for query processing since we perform a local clustering based on the order of Hilbert-curve. Finally, we show from performance analysis that the proposed scheme outperforms the existing scheme.
Manuel Castells - One of the best experts on this subject based on the ideXlab platform.
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globalisation networking urbanisation reflections on the Spatial dynamics of the information age
Urban Studies, 2010Co-Authors: Manuel CastellsAbstract:The network society is a global society because networks have no boundaries. Spatial Transformation is a fundamental dimension of this new social structure. The global process of urbanisation that ...
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globalisation networking urbanisation reflections on the Spatial dynamics of the information age
Urban Studies, 2010Co-Authors: Manuel CastellsAbstract:The network society is a global society because networks have no boundaries. Spatial Transformation is a fundamental dimension of this new social structure. The global process of urbanisation that we are experiencing in the early 21st century is characterised by the formation of a new Spatial architecture in our planet, made up of global networks connecting major metropolitan regions and their areas of influence. Since the networking form of territorial arrangements also extends to the intrametropolitan structure, our understanding of contemporary urbanisation should start with the study of these networking dynamics in both the territories that are included in the networks and in the localities excluded from the dominant logic of global Spatial integration.
Hyeongil Kim - One of the best experts on this subject based on the ideXlab platform.
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hilbert curve based cryptographic Transformation scheme for Spatial query processing on outsourced private data
Data and Knowledge Engineering, 2016Co-Authors: Hyeongil Kim, Seungtae Hong, Jaewoo ChangAbstract:Research on preserving location data privacy in outsourced databases has been spotlighted with the development of cloud computing. However, the existing Spatial Transformation schemes are vulnerable to various attack models. The existing cryptographic Transformation scheme provides good data privacy, but it has a high query processing cost. To improve privacy and reduce cost, we propose a Hilbert curve-based cryptographic Transformation scheme to preserve the privacy of the Spatial data from various attacks on outsourced databases. We also provide efficient range and k-NN query processing algorithms using a Hilbert-order index. A performance analysis confirms that the proposed scheme is robust against attack models and achieves better query processing performance than the existing cryptographic Transformation scheme.
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hilbert curve based cryptographic Transformation scheme for protecting data privacy on outsourced private Spatial data
International Conference on Big Data and Smart Computing, 2014Co-Authors: Hyeongil Kim, Seungtae Hong, Jaewoo ChangAbstract:The study on Spatial database outsourcing has been spotlighted with the development of cloud computing. Therefore, researches for protecting location data privacy in outsourced database have been studied. However, the existing Spatial Transformation schemes are vulnerable to naive attack models. The existing cryptographic Transformation scheme provides high data privacy, but it causes the high query processing cost. To solve these problems, in this paper we propose a Hilbert-curve based cryptographic Transformation scheme to protect data privacy and to improve the efficiency of the query processing in outsourced databases. The proposed scheme reduces the communication cost for query processing since we perform a local clustering based on the order of Hilbert-curve. Finally, we show from performance analysis that the proposed scheme outperforms the existing scheme.
Seungtae Hong - One of the best experts on this subject based on the ideXlab platform.
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hilbert curve based cryptographic Transformation scheme for Spatial query processing on outsourced private data
Data and Knowledge Engineering, 2016Co-Authors: Hyeongil Kim, Seungtae Hong, Jaewoo ChangAbstract:Research on preserving location data privacy in outsourced databases has been spotlighted with the development of cloud computing. However, the existing Spatial Transformation schemes are vulnerable to various attack models. The existing cryptographic Transformation scheme provides good data privacy, but it has a high query processing cost. To improve privacy and reduce cost, we propose a Hilbert curve-based cryptographic Transformation scheme to preserve the privacy of the Spatial data from various attacks on outsourced databases. We also provide efficient range and k-NN query processing algorithms using a Hilbert-order index. A performance analysis confirms that the proposed scheme is robust against attack models and achieves better query processing performance than the existing cryptographic Transformation scheme.
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hilbert curve based cryptographic Transformation scheme for protecting data privacy on outsourced private Spatial data
International Conference on Big Data and Smart Computing, 2014Co-Authors: Hyeongil Kim, Seungtae Hong, Jaewoo ChangAbstract:The study on Spatial database outsourcing has been spotlighted with the development of cloud computing. Therefore, researches for protecting location data privacy in outsourced database have been studied. However, the existing Spatial Transformation schemes are vulnerable to naive attack models. The existing cryptographic Transformation scheme provides high data privacy, but it causes the high query processing cost. To solve these problems, in this paper we propose a Hilbert-curve based cryptographic Transformation scheme to protect data privacy and to improve the efficiency of the query processing in outsourced databases. The proposed scheme reduces the communication cost for query processing since we perform a local clustering based on the order of Hilbert-curve. Finally, we show from performance analysis that the proposed scheme outperforms the existing scheme.
Douglas H. Werner - One of the best experts on this subject based on the ideXlab platform.
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Spatial Transformation enabled electromagnetic devices from radio frequencies to optical wavelengths
Philosophical Transactions of the Royal Society A, 2015Co-Authors: Zhi Hao Jiang, J P Turpin, Kennith Morgan, Douglas H. WernerAbstract:Transformation optics provides scientists and engineers with a new powerful design paradigm to manipulate the flow of electromagnetic waves in a user-defined manner and with unprecedented flexibility, by controlling the Spatial distribution of the electromagnetic properties of a medium. Using this approach, over the past decade, various previously undiscovered physical wave phenomena have been revealed and novel electromagnetic devices have been demonstrated throughout the electromagnetic spectrum. In this paper, we present versatile theoretical and experimental investigations on designing Transformation optics-enabled devices for shaping electromagnetic wave radiation and guidance, at both radio frequencies and optical wavelengths. Different from conventional coordinate Transformations, more advanced and versatile coordinate Transformations are exploited here to benefit diverse applications, thereby providing expanded design flexibility, enhanced device performance, as well as reduced implementation complexity. These design examples demonstrate the comprehensive capability of Transformation optics in controlling electromagnetic waves, while the associated novel devices will open up new paths towards future integrated electromagnetic component synthesis and design, from microwave to optical spectral regimes.
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conformal mappings to achieve simple material parameters for Transformation optics devices
Optics Express, 2010Co-Authors: Jeremiah P Turpin, Zhi Hao Jiang, Ayah T Massoud, Pingjuan L Werner, Douglas H. WernerAbstract:The Transformation optics technique for designing novel electromagnetic and optical devices offers great control over wave behavior, but is difficult to implement primarily due to limitations in current metamaterial design and fabrication techniques. This paper demonstrates that restricting the Spatial Transformation to a conformal mapping can lead to much simpler material parameters for more practical implementation. As an example, a flat cylindrical-to-plane-wave conversion lens is presented and its performance validated through numerical simulations. It is shown that the lens dimensions and embedded source location can be adjusted to produce one, two, or four highly directive planar beams. Two metamaterial designs for this lens that implement the required effective medium parameters are proposed and their behavior analyzed.
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Two-dimensional electromagnetic cloak having a uniform thickness for elliptic cylindrical regions
Applied Physics Letters, 2008Co-Authors: Do-hoon Kwon, Douglas H. WernerAbstract:A two-dimensional electromagnetic cloak recipe having a uniform thickness is presented for cloaked regions of elliptic cylindrical shape. The cloak material parameters are obtained from the Spatial Transformation approach. The effectiveness of the cloak design is verified by full-wave simulations of plane wave scattering from uncloaked and cloaked conducting elliptic cylinders. The proposed design provides a more practical cloak geometry when compared to previous designs that have the outer boundary limited only to a scaled version of the inner boundary.
