The Experts below are selected from a list of 85044 Experts worldwide ranked by ideXlab platform
Junshan Zhang - One of the best experts on this subject based on the ideXlab platform.
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privacy preserving database assisted spectrum access for industrial internet of things a distributed learning Approach
IEEE Transactions on Industrial Electronics, 2020Co-Authors: Mengyuan Zhang, Jiming Chen, Lei Yang, Xiaowen Gong, Junshan ZhangAbstract:Industrial Internet of Things (IIoT) has been shown to be of great value to the deployment of smart industrial environment. With the immense growth of Internet of Things (IoT) devices, dynamic spectrum sharing is introduced, envisaged as a promising solution to the spectrum shortage in IIoT. Meanwhile, cyber–physical safety issue remains to be a great concern for the reliable operation of IIoT system. In this article, we consider the dynamic spectrum access in IIoT under a received signal strength-based adversarial localization attack. We employ a practical and effective power Perturbation Approach to mitigate the localization threat on the IoT devices and cast the privacy-preserving spectrum sharing problem as a stochastic channel selection game. To address the randomness induced by the power Perturbation Approach, we develop a two-timescale distributed learning algorithm that converges almost surely to the set of correlated equilibria of the game. The numerical results show the convergence of the algorithm and corroborate that the design of two-timescale learning process effectively alleviates the network throughput degradation brought by the power Perturbation procedure.
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privacy preserving database assisted spectrum access a socially aware distributed learning Approach
Global Communications Conference, 2014Co-Authors: Mengyuan Zhang, Lei Yang, Xiaowen Gong, Donghoon Shin, Junshan ZhangAbstract:In this paper, we study a privacy-preserving spectrum sharing system to protect secondary users' location privacy while enhancing spectrum access. The location privacy of secondary users can be compromised by an external adversary via the received signal strength (RSS)-based localization technique. To mitigate such privacy threat, we employ a random power Perturbation Approach that allows each secondary user to judiciously obfuscate the RSS captured by the adversary. While it can protect users' location privacy, the power Perturbation Approach would inevitably degrade the system performance and bring challenges to the design of the spectrum allocation algorithm. In this work, we adopt a socially-aware database assisted spectrum access system and cast the spectrum allocation under users' power Perturbation as a stochastic channel selection game played among the users. To tackle the challenge brought by the privacy protection, we develop a two time-scale distributed learning algorithm, which is shown to converge almost surely to a socially-aware e-Nash equilibrium. The numerical results show that the higher the privacy protection level is, the more significant the degradation of the network throughput would be.
Kyungsoo Kim - One of the best experts on this subject based on the ideXlab platform.
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an impulse time Perturbation Approach for a symmetric extra insensitive input shaper
International Journal of Control Automation and Systems, 2018Co-Authors: Dongwook Lee, Keunho Rew, Kyungsoo KimAbstract:In this study, symmetric Perturbation extra-insensitive input shapers (SPEI-ISs) are proposed to enhance the robustness of the impulse-time Perturbation Approach, particularly toward the low-frequency range, with respect to the modeled natural frequency. These Perturbation-based extra-insensitive input shapers (PEI-ISs) provide a wider range of robustness than the well-known robust input shapers, which include derivative input shapers (e.g., ZVD, ZVDD, and ZVDDD shapers) and extra-insensitive input shapers (EI-ISs). However, robustness may be lost, particularly at lower frequencies, as a result of asymmetric placement of the notch points on the sensitivity curve. To address this issue, an SPEI-IS is derived by placing the notch points symmetrically to enhance robustness, particularly in the low-frequency range. In single-, two-and three-hump cases, explicit solutions are presented to demonstrate the usability of the proposed shapers. The robustness and transient response are evaluated through simulation and experiment and are compared to the response of conventional robust input shapers. It is concluded that the proposed SPEI-IS improves robustness and transient response.
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an impulse time Perturbation Approach for enhancing the robustness of extra insensitive input shapers
Automatica, 2013Co-Authors: Keunho Rew, Kyungsoo KimAbstract:In this paper, Perturbation-based extra-insensitive input shapers (PEI-ISs) are proposed to enhance the robustness of the input shaping technique. The extra-insensitive input shaper (EI-IS) has been known to be more robust than the so-called derivative input shapers such as ZVD, ZVDD, and ZVDDD shapers. However, the robustness of the known EI-IS is restricted by the symmetric property in the sensitivity curve. To address this, the PEI-IS is devised by multiplying a series of input shapers in the Laplace domain, of which the impulse times are slightly perturbed from those of the zero vibration (ZV) shaper. For a single-hump case, a closed-form solution to the PEI-IS is provided. For two- and three-hump cases, the approximate solutions are presented. The robustness is evaluated by simulations and assessed by means of the insensitivity. It will be shown that the proposed PEI-IS does improve the robustness and that it can be easily designed.
Mengyuan Zhang - One of the best experts on this subject based on the ideXlab platform.
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privacy preserving database assisted spectrum access for industrial internet of things a distributed learning Approach
IEEE Transactions on Industrial Electronics, 2020Co-Authors: Mengyuan Zhang, Jiming Chen, Lei Yang, Xiaowen Gong, Junshan ZhangAbstract:Industrial Internet of Things (IIoT) has been shown to be of great value to the deployment of smart industrial environment. With the immense growth of Internet of Things (IoT) devices, dynamic spectrum sharing is introduced, envisaged as a promising solution to the spectrum shortage in IIoT. Meanwhile, cyber–physical safety issue remains to be a great concern for the reliable operation of IIoT system. In this article, we consider the dynamic spectrum access in IIoT under a received signal strength-based adversarial localization attack. We employ a practical and effective power Perturbation Approach to mitigate the localization threat on the IoT devices and cast the privacy-preserving spectrum sharing problem as a stochastic channel selection game. To address the randomness induced by the power Perturbation Approach, we develop a two-timescale distributed learning algorithm that converges almost surely to the set of correlated equilibria of the game. The numerical results show the convergence of the algorithm and corroborate that the design of two-timescale learning process effectively alleviates the network throughput degradation brought by the power Perturbation procedure.
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privacy preserving database assisted spectrum access a socially aware distributed learning Approach
Global Communications Conference, 2014Co-Authors: Mengyuan Zhang, Lei Yang, Xiaowen Gong, Donghoon Shin, Junshan ZhangAbstract:In this paper, we study a privacy-preserving spectrum sharing system to protect secondary users' location privacy while enhancing spectrum access. The location privacy of secondary users can be compromised by an external adversary via the received signal strength (RSS)-based localization technique. To mitigate such privacy threat, we employ a random power Perturbation Approach that allows each secondary user to judiciously obfuscate the RSS captured by the adversary. While it can protect users' location privacy, the power Perturbation Approach would inevitably degrade the system performance and bring challenges to the design of the spectrum allocation algorithm. In this work, we adopt a socially-aware database assisted spectrum access system and cast the spectrum allocation under users' power Perturbation as a stochastic channel selection game played among the users. To tackle the challenge brought by the privacy protection, we develop a two time-scale distributed learning algorithm, which is shown to converge almost surely to a socially-aware e-Nash equilibrium. The numerical results show that the higher the privacy protection level is, the more significant the degradation of the network throughput would be.
A Pashov - One of the best experts on this subject based on the ideXlab platform.
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a regularized inverted Perturbation Approach method potential energy curve of the 4 1σu state in na2
Journal of Chemical Physics, 2004Co-Authors: A Grochola, P Kowalczyk, W Jastrzebski, A PashovAbstract:We describe a modification of the inverted Perturbation Approach method allowing to construct physically sensible potential energy curves for electronic states of diatomic molecules even when some parts of the potential are not adequately characterized by the experimental data. The method is based on a simple regularization procedure, imposing an additional constraint on the constructed potential curve. In the present work it is applied to the double minimum 4 (1)Sigma(u) (+) state of Na(2), observed experimentally by polarization labeling spectroscopy technique.
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the li2 f 1σg shelf state accurate potential energy curve based on the inverted Perturbation Approach
Journal of Chemical Physics, 2000Co-Authors: A Pashov, W Jastrzȩbski, P KowalczykAbstract:We report an accurate inverted Perturbation Approach (IPA) potential energy curve for the “shelf” F 1Σg+ state in Li2 which reproduces positions of the experimental energy levels available in the literature for all three isotopomers 7Li2, 6Li7Li, and 6Li2 with a standard deviation of 0.11 cm−1. Our analysis significantly improves the shape of the recently reported Rydberg–Klein–Rees (RKR) potential curve of the F 1Σg+ state [Antonova et al., J. Chem. Phys. 112, 7080 (2000)] and provides evidence for the existence of a shallow minimum in the shelf region. Using our IPA potential curve we were able to localize and identify some local Perturbations in the spectra, as well as to correct the assignment of several spectral lines previously observed experimentally.
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an improved description of the double minimum 6 1σ state of nak by an ipa potential energy curve
Journal of Physics B, 2000Co-Authors: A Pashov, W Jastrzebski, Pawel KowalczykAbstract:The inverted Perturbation Approach (IPA) method is used to construct the potential energy curve of the double minimum 6 1Σ+ state of NaK. The IPA potential makes it possible to reproduce the experimental energies of 1032 rovibrational levels situated both in the inner well and above the internal maximum of the potential.
Hideyuki Tagoshi - One of the best experts on this subject based on the ideXlab platform.
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Analytic Black Hole Perturbation Approach to Gravitational Radiation
Living Reviews in Relativity, 2003Co-Authors: Misao Sasaki, Hideyuki TagoshiAbstract:We review the analytic methods used to perform the post-Newtonian expansion of gravitational waves induced by a particle orbiting a massive, compact body, based on black hole Perturbation theory. There exist two different methods of performing the post-Newtonian expansion. Both are based on the Teukolsky equation. In one method, the Teukolsky equation is transformed into a Regge-Wheeler type equation that reduces to the standard Klein Gordon equation in the flat-space limit, while in the other method (which was introduced by Mano, Suzuki, and Takasugi relatively recently, the Teukolsky equation is used directly in its original form. The former’s advantage is that it is intuitively easy to understand how various curved space effects come into play. However, it becomes increasingly complicated when one goes to higher and higher post-Newtonian orders. In contrast, the latter’s advantage is that a systematic calculation to higher post-Newtonian orders can be implemented relatively easily, but otherwise, it is so mathematical that it is hard to understand the interplay of higher order terms. In this paper, we review both methods so that their pros and cons may be seen clearly. We also review some results of calculations of gravitational radiation emitted by a particle orbiting a black hole.
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analytic black hole Perturbation Approach to gravitational radiation
arXiv: General Relativity and Quantum Cosmology, 2003Co-Authors: Misao Sasaki, Hideyuki TagoshiAbstract:We review analytic methods to perform the post-Newtonian expansion of gravitational waves induced by a particle orbiting a massive compact body, based on the black hole Perturbation theory. There exist two different methods of the post-Newtonian expansion. Both are based the Teukolsky equation. In one method, the Teukolsky equation is transformed into a Regge-Wheeler type equation that reduces to the standard Klein-Gordon equation in the flat space limit, while in the other method, which were introduced by Mano, Suzuki and Takasugi relatively recently, the Teukolsky equation is directly used in its original form. The former has an advantage that it is intuitively easy to understand how various curved space effects come into play. However, it becomes increasingly complicated when one goes on to higher and higher post-Newtonian orders. In contrast, the latter has an advantage that a systematic calculation to higher post-Newtonian orders is relatively easily implementable, but otherwise so mathematical that it is hard to understand the interplay of higher order terms. In this paper, we review both methods so that their pros and cons may be clearly seen. We also review some results of calculations of gravitational radiation emitted by a particle orbiting a black hole.