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Robust active vibration control of piezoelectric flexible structures using deterministic and probabilistic analysis

JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES 2014年第6期25卷 665-679页

作者： Zhang, Kai Scorletti, Gerard Ichchou, Mohamed N. Mieyeville, Fabien Ecole Cent Lyon Lab Tribol & Dynam Syst F-69134 Ecully France Ecole Cent Lyon Lab Ampere F-69134 Ecully France Ecole Cent Lyon Inst Nanotechnol Lyon F-69134 Ecully France

The main objective of this article is to propose a general and systematic robust control methodology for active vibration control of piezoelectric flexible structures such that the probabilistic information of parametric uncertainties can be investigated, and the robustness properties of the closed-loop system can be quantitatively ensured. For the purpose, the modal parameter identification is performed based on the finite element analysis to have the reduced nominal dynamical models. The generalized polynomial chaos framework is employed for uncertainty analysis to obtain the probabilistic information of parametric uncertainties. In the presence of probabilistic parametric and dynamic uncertainties, phase and gain control policies-based H infinity output feedback control is used for the controller design to ensure a set of control objectives simultaneously, and then deterministic and probabilistic robustness analyses are conducted to quantitatively verify the robustness properties of the closed-loop system both in the deterministic sense and in the probabilistic one. The design process and the effectiveness of the proposed control methodology are illustrated via active vibration control of a piezoelectric cantilever beam.

关键词： H infinity control mu/nu analysis probabilistic parametric uncertainties random algorithm generalized polynomial chaos phase and gain control policies

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Local-to-global background modeling for moving object detection from non-static cameras

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MULTIMEDIA TOOLS AND APPLICATIONS 2017年第8期76卷 11003-11019页

作者： Zheng, Aihua Zhang, Lei Zhang, Wei Li, Chenglong Tang, Jin Luo, Bin Anhui Univ Sch Comp Sci & Technol Hefei 230601 Peoples R China Key Lab Ind Image Proc & Anal Anhui Prov Hefei 230601 Peoples R China

This paper investigates efficient and robust moving object detection from non-static cameras. To tackle the motion of background caused by moving cameras and to alleviate the interference of noises, we propose a local-to-global background model for moving object detection. Firstly, motion compensation based local location-specific background model is deployed to roughly detect the foreground regions in non-static cameras. More specifically, the local background model is built for each pixel and represented by a set of pixel values drawn from its location and neighborhoods. Each pixel can be classified as foreground or background pixel according to the compensated background model based on the fast optical flow. Secondly, we estimate the global background model by the rough superpixel-based background regions to further separate foregrounds from background accurately. In particular, we use the superpixel to generate the initial background regions based on the detection results generated by local background model to alleviate the noises. Then, a Gaussian Mixture Model (GMM) is estimated for the backgrounds on superpixel level to refine the foreground regions. Extensive experiments on newly created dataset, including 10 challenging video sequences recorded in PTZ cameras and hand-held cameras, suggest that our method outperforms other state-of-the-art methods in accuracy.

关键词： Background modeling Object detection Non-static cameras Motion compensation random algorithm Superpixel processing Gaussian mixture model

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The Quicksort process

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STOCHASTIC PROCESSES AND THEIR APPLICATIONS 2014年第2期124卷 1036-1054页

作者： Ragab, Mahmoud Roesler, Uwe Al Azhar Univ Fac Sci Dept Math Cairo 11884 Egypt Christian Albrechts Univ Kiel Math Seminar D-24098 Kiel Germany

Quicksort on the fly returns the input of n reals in increasing natural order during the sorting process. Correctly normalized the running time up to returning the l-th smallest out of n seen as a process in 1 converges weakly to a limiting process with path in the space of cadlag functions. (C) 2013 Elsevier B.V. All rights reserved.

关键词： Sorting Quicksort Divide and conquer algorithm random algorithm Running time analysis Stochastic process Cadlag functions Asymptotics Skorodhod metric

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On Sidon-Ramsey Numbers

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JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE 2013年第4期10卷 884-887页

作者： Liang, Meilian Li, Xiangmei Xu, Baoxin Xu, Xiaodong Guangxi Univ Sch Math & Informat Sci Nanning 530004 Peoples R China Chengdu Univ Informat Technol Coll Network Engn Chengdu 100106 Peoples R China Natl Univ Def Technol Coll Informat Syst & Management Changsha 410073 Hunan Peoples R China Guangxi Acad Sci Nanning 530007 Guangxi Peoples R China

A set {a(i) vertical bar 1 = 2, a new Ramsey type number based on Sidon set, Sidon-Ramsey number SR(k), is defined to be the smallest n such that in any k-coloring of {1, ... , n}, there is at least one monochromatic ... 详细信息

A set {a(i) vertical bar 1 <= i <= k} of integers is a Sidon set if the sums a(i) + a(j), for any i <= j, are all different. Let f(N) denote the maximum integer k for which there exists a Sidon set {a(i) vertical bar 1 <= i <= k} such that 1 <= a(1) < ... < a(k) <= N. Let the Sidon number F(k) = min{n vertical bar f(n) = k}. For given integer k >= 2, a new Ramsey type number based on Sidon set, Sidon-Ramsey number SR(k), is defined to be the smallest n such that in any k-coloring of {1, ... , n}, there is at least one monochromatic subset which is not a Sidon set. In this paper, upper bounds for some Sidon-Ramsey numbers are given based the known results on Sidon numbers, and lower bounds for some small Sidon-Ramsey numbers are obtained by a random algorithm, among which SR(k) is determined for k is an element of {2, 3, 4, 5}.

关键词： Sidon Sequence Golomb Ruler Ramsey Theory random algorithm

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NEW EFFICIENT AND ROBUST HSS CHOLESKY FACTORIZATION OF SPD MATRICES

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SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS 2012年第3期33卷 886-904页

作者： Li, Shengguo Gu, Ming Wu, Cinna Julie Xia, Jianlin Univ Def Technol Coll Sci Changsha 410073 Hunan Peoples R China Univ Calif Berkeley Dept Math Berkeley CA 94720 USA Purdue Univ Dept Math W Lafayette IN 47907 USA

In this paper, we propose a robust Cholesky factorization method for symmetric positive definite (SPD), hierarchically semiseparable (HSS) matrices. Classical Cholesky factorizations and some semiseparable methods need to sequentially compute Schur complements. In contrast, we develop a strategy involving orthogonal transformations and approximations which avoids the explicit computation of the Schur complement in each factorization step. The overall factorization requires fewer floating point operations and has better data locality when compared to the recent HSS method in [J. Xia and M. Gu, SIAM J. Matrix Anal. Appl., 31 (2010), pp. 2899-2920]. Our strategy utilizes a robustness technique so that an approximate generalized Cholesky factorization is guaranteed to exist. We test three different methods for compressing the off-diagonal blocks in each iteration, i.e., rank-revealing QR, SVD, and SVD with random sampling. In our comparisons, we find that, with high probability, using SVD with random sampling is fast and stable. The complexity of the methods proposed in this paper is analyzed and shown to be O(N(2)k), where N is the dimension of matrix and k is the maximum off-diagonal (numerical) rank. Numerical results from applications show the efficiency of our method and its effectiveness as a preconditioner. Moreover, our techniques are helpful in improving the scalability and robustness of other rank-structured methods.

关键词： robust preconditioner hierarchical semiseparable matrices random algorithm rank-revealing QR SVD

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Choices, intervals and equidistribution

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ELECTRONIC JOURNAL OF PROBABILITY 2015年第none期20卷 1-18页

作者： Junge, Matthew Univ Washington Seattle WA 98195 USA

We give a sufficient condition for a random sequence in [0,1] generated by a Psi-process to be equidistributed. The condition is met by the canonical example - the max-2 process - where the nth term is whichever of two uniformly placed points falls in the larger gap formed by the previous n - 1 points. This solves an open problem from Itai Benjamini, Pascal Maillard and Elliot Paquette. We also deduce equidistribution for more general Psi-processes. This includes an interpolation of the min-2 and max-2 processes that is biased towards min-2.

关键词： interval splitting random algorithm equidistribution subdivision max-2 power of choice balls and bins

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SIMULATED ANNEALING - PRACTICE VERSUS THEORY

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MATHEMATICAL AND COMPUTER MODELLING 1993年第11期18卷 29-57页

作者： INGBER, L Lester Ingber Research P.O.B. 857 McLean VA 22101 U.S.A.

Simulated annealing (SA) presents an optimization technique with several striking positive and negative features. Perhaps its most salient feature, statistically promising to deliver an optimal solution, in current practice is often spurned to use instead modified faster algorithms, ''simulated quenching'' (SQ). Using the author's Adaptive Simulated Annealing (ASA) code, some examples are given which demonstrate how SQ can be much faster than SA without sacrificing accuracy.

关键词： SIMULATED ANNEALING random algorithm OPTIMIZATION TECHNIQUE

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NONSTANDARD METHODS IN EVOLUTIONARY COMPUTATION

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STATISTICS AND COMPUTING 1994年第2期4卷 141-155页

作者： MICHALEWICZ, Z UNIV N CAROLINA DEPT COMP SCI CHARLOTTE NC 28223 USA

The paper presents non-standard methods in evolutionary computation and discusses their applicability to various optimization problems. These methods maintain populations of individuals with nonlinear chromosomal stru... 详细信息

关键词： EVOLUTIONARY COMPUTATION GENETIC algorithm random algorithm OPTIMIZATION TECHNIQUE

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Optimal spectrum assignment for cognitive radio sensor networks under coverage constraint

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IET COMMUNICATIONS 2014年第18期8卷 3318-3325页

作者： Eletreby, Rashad M. Elsayed, Hany M. Khairy, Mohamed M. Cairo Univ Fac Engn Dept Elect & Elect Commun Engn Cairo Egypt

Cognitive radios emerged as a solution to spectrum scarcity problem. The integration of cognitive radios and wireless sensor networks enables a new paradigm of communication, in which the sensor nodes can avoid heavily-crowded transmission bands by tuning their transmission parameters to less-crowded bands. The authors consider the problem of spectrum assignment for cognitive radio sensor network (CRSN) under coverage, interference, minimum data rate and power budget constraints. A mixed-integer non-linear programming problem formulation that addresses optimal power allocation, channel selection and node scheduling is presented. Following a practical assumption, that any CRSN node can only access one channel for its transmission with the CRSN base station, the problem is transformed to a binary linear programming (BLP) problem. Using the relaxation techniques, the problem is transformed to a linear programming problem that is solvable in polynomial time, and has the same optimal solution of the BLP problem. Hence, the minimum power algorithm that achieves the optimal solution of our problem is proposed. To further reduce the complexity of the solution, three heuristic lower-complexity algorithms are proposed to solve the problem: random, greedy and two-stage (decoupled) algorithms.

关键词： radio spectrum management cognitive radio radio networks wireless sensor networks radiofrequency interference nonlinear programming integer programming scheduling wireless channels linear programming polynomials greedy algorithms random processes optimal spectrum assignment cognitive radio sensor network spectrum scarcity problem wireless sensor network heavily-crowded transmission band avoidance CRSN interference power budget constraint minimum data rate constraint mixed-integer nonlinear programming problem optimal power allocation channel selection node scheduling base station binary linear programming problem BLP problem relaxation technique polynomial time minimum power algorithm heuristic lower-complexity algorithm random algorithm greedy algorithm two-stage algorithm decoupled algorithm

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Selective-Encrypted GIS Vector Map with Low Complexity

Selective-Encrypted GIS Vector Map with Low Complexity

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International Conference on Information Networking (ICOIN)

作者： Park, Jin-Hyeok Giao, Pham Ngoc Seung, Teak-Young Kwon, Ki-Ryong Moon, Kwang-Seok Kwon, Gi-Chang Lee, Suk-Hwan Pukyong Natl Univ Dept IT Convergence & Applicat Engn Busan South Korea Pukyong Natl Univ Dept Elect Engn Busan South Korea Gyeongbuk Prov Coll Dept IT Cooperat Syst Busan South Korea Tongmyong Univ Dept Informat Secur Busan South Korea

ISBN: (纸本)9781479983421

Recently years, vector map has many advantages than raster map when it is used in many domains as research, education, military or digital map services. And in most cases vector map data contains confidential information which must be kept away from unauthorized users. Moreover, the producing process of a vector map is considerably complex, and the maintenance of a digital map requires substantial monetary, human resources. With the rapid development of vector map contents, a large volume of valuable vector map dataset has been illegal distributed by pirates, hackers or unauthorized users. Therefore the problem focuses on how to protect the vector map data for multimedia applications, storage and transmission. This paper presents the selective encryption algorithm for vector map protection for storage, transmission, distribution to authorized users. In proposed algorithm, we just select some values of polylines and polygons in DCT domain to encrypt by random algorithms and cryptography. Experimental results verified that proposed algorithm is effectively and security. Maps are changed whole after encryption process, and unauthorized users cannot access to copy or use them. Encrypted maps do not alter the size of file and it does not have loss accuracy. The error between original map and decrypted map is approximate zero

关键词： GIS vector map digital vector map selective encryption random algorithm DCT

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