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Seismic response of adjacent filled parallel rock fractures with dissimilar properties

JOURNAL OF APPLIED GEOPHYSICS 2013年 96卷 33-37页

作者： Wu, W. Li, J. C. Zhao, J. Ecole Polytech Fed Lausanne Sch Architecture Civil & Environm Engn Lab Rock Mech LMR CH-1015 Lausanne Switzerland Chinese Acad Sci Inst Rock & Soil Mech State Key Lab Geomech & Geotech Engn Wuhan 430071 Peoples R China

The purpose of this study is to analytically predict and to experimentally investigate the seismic response of adjacent filled parallel rock fractures with dissimilar properties (e.g., fracture thickness and stiffness). The time-domain recursive method is extended to predict that a P-wave propagates normally across the filled parallel fractures using the specific stiffness of each filled fracture and considering multiple wave reflections between the parallel fractures. The split Hopkinson rock bar technique is modified to simulate P-wave propagation normally across the sand-filled parallel fractures and to characterize the stress-closure relation of each sand-filled fracture. The P-wave transmission and the seismic response of the filled parallel fractures are an interactive process. The experimental results show the decreases of loading rate and dominant frequency when the P-wave propagates across each sand-filled fracture. The P-wave transmitted from the first sand-filled fracture strongly affects the seismic response of the second one. The P-wave attenuation in the filled parallel fractures is mainly due to the dynamic compaction of the filling sands. By comparison, the analytical method provides a satisfactory prediction to the experimental result. This study suggests considering the specific stiffness of each filled fracture to precisely predict the seismic response of filled parallel rock fractures. (C) 2013 Elsevier B.V. All rights reserved.

关键词： P-wave propagation Filled parallel fractures recursive method Specific fracture stiffness Wave transmission coefficient

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Dynamical characteristics of infinite and semi-infinite 1D structures with defects in presence of activation

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SYNTHETIC METALS 2001年第1-3期121卷 1333-1334页

作者： Feodosyev, S Mamalui, M Syrkin, E NAS Ukraine Inst Low Temp Phys & Engn UA-61164 Kharkov Ukraine

Exact analytic expressions are obtained for Green's functions of chain-like structures with defects in presence of activation. Two-atomic impurity molecule in one-atomic chain is considered. The conditions for the formation and peculiar features of high- and low-frequency local vibrations, and the evolution of treshold values of masses of two isotopic impurities necessary for formation of localized states depending on distance between the impurities are investigated. The results obtained can be used to analyze the quasiparticle spectrum of a wide class of quasi-1D organic conductors.

关键词： localized state Green's function Jacobian matrix method recursive method impurity activation

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Accurate and fast Jacobi-Fourier moments for invariant image recognition

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OPTIK 2016年第19期127卷 7925-7940页

作者： Upneja, Rahul Sri Guru Granth Sahib World Univ Dept Math Fatehgarh Sahib India Univ Manitoba Dept Elect & Comp Engn Winnipeg MB Canada

The Jacobi-Fourier moments (JFMs) which are useful for many image processing, pattern recognition and computer vision applications provide a wide class of orthogonal rotation invariant moments (ORIMs). The accuracy of JFMs suffers from various errors, such as the geometric error, numerical integration error, and discretization error. Moreover, the high order moments are vulnerable to numerical instability. In this paper, we present a fast method for the accurate calculation of JFMs which not only removes the geometric error and numerical integration error, but also provides numerical stability to JFMs of high orders. (C) 2016 Elsevier GmbH. All rights reserved.

关键词： Jacobi-Fourier moments recursive method Numerical stability Accurate moments Pattern recognition applications

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Bootstrapping Computation of Availability for a Repairable System with Standby Subject to Imperfect Switching

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COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION 2011年第4期40卷 469-483页

作者： Liu, Tzu-Hsin Ke, Jau-Chuan Hsu, Yu-Lun Hsu, Ying-Lin Natl Chung Hsing Univ Dept Appl Math Taichung 402 Taiwan Natl Chung Hsing Univ Inst Stat Taichung 402 Taiwan Natl Taichung Inst Technol Dept Appl Stat Taichung Taiwan

This article deals with the availability behavior of a repairable system in which standby switched to primary is subject to breakdowns. The time-to-failure of the four primary and two standby units are assumed to be exponentially and generally distributed. In addtion, the repair time of service station follow four common distributions: exponential (EXP), Gamma (G), Uniform (U), and Mixture (M). We use a recursive method, and the supplementary variable technique to develop the steady-state availability, Av. The estimator [image omitted] is strongly consistent and asymptotically normal. The interval estimations of Av are constructed by five bootstrap approaches: standard bootstrap confidence interval (SB), the percentile bootstrap confidence interval (PB), the bias-corrected percentile bootstrap confidence interval (BCPB), the bias-corrected and accelerated confidence interval (BCa), and bootstrap pivot confidence interval (BP). Finally, some simulation computations are conducted in order to describe the performances of [image omitted] on various interval estimation by calculating the coverage percentage and the average length of intervals.

关键词： Availability Bootstrap method recursive method Repairable system Simulation Supplementary variable technique

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Definition of Instantaneous Dielectric Loss Factor and Digital Algorithm for Online Monitoring

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2009年第3期58卷 666-673页

作者： Li, Qingmin Zhang, Li Zhao, Tong Shandong Univ Sch Elect Engn Jinan 250061 Peoples R China

Among the digital algorithms currently alvailable for online monitoring of the dielectric loss factor of power apparatus, there are unavoidable limitations, such as that most of them must strictly meet the synchronous sampling criterion simultaneously with a precondition that the power frequency must be invariable in the sampling periods. This paper presents a unique definition and a corresponding digital algorithm of the instantaneous dielectric loss factor. The theoretical basis of the algorithm is also deduced. In a nonstationary signal environment where power frequencies are randomly variable, the algorithm can accurately track the instantaneous frequency of power signals, recursively calculate the parameters of parallel equivalent circuit, and, finally, figure out the waveform of the instantaneous dielectric loss factor. Simulations and experimental results show that the proposed algorithm renders good application performance without being affected by the limitations incurred from synchronous sampling and harmonics.

关键词： Digital algorithms frequency tracking instantaneous dielectric loss factor online monitoring recursive method

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A new algorithm for a recursive construction of the minimal interpolation space

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MATHEMATICS AND COMPUTERS IN SIMULATION 2009年第12期79卷 3587-3598页

作者： Sbibih, D. Serghini, A. Tijini, A. Univ Mohammed 1 FSO MATSI Lab Oujda Morocco

In this work, we introduce a new interpolation algorithm, based on a recursive method for computing Lagrange interpolants. This algorithm allows to construct recursively the minimal interpolation space (see [1]) with respect to a finite set of points. We also extend this recursive method to the osculatory interpolation problem. (C) 2009 IMACS. Published by Elsevier B.V. All rights reserved.

关键词： recursive method Multivariate interpolant Minimal interpolation space

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A Novel Online Scheduling Algorithm and Hierarchical Protocol for Large-Scale EV Charging Coordination

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IEEE ACCESS 2019年 7卷 101376-101387页

作者： Yang, Shaobing Zhang, Shanshan Ye, Jingjing Beijing Jiaotong Univ Sch Elect Engn Beijing 100044 Peoples R China

For electric vehicle (EV) charging coordination, relaxation and approximation methods are usually employed to improve scheduling efficiency in solving integer linear programming (ILP) problems. Nevertheless, they have a few inherent flaws, such as frequent charging interruption and large deviation in final SOC. Based on the recursive method, this paper proposes a search-swapping algorithm (SSA) for optimal approximation. It leverages the non-aftereffect property of charging scheduling to approximate the optimal solution as well as uses single recursion instead of multiple recursion to reduce computation cost from exponential time to polynomial time. Compared with the conventional algorithms, it has much higher efficiency, less charging interruption, and better final SOC uniformity. Furthermore, a single-round interactive protocol is designed for hierarchical coordinated framework to achieve power dispatch. Numerous simulations show that the SSA has outstanding efficiency and satisfactory optimality.

关键词： Charging coordination electric vehicle (EV) hierarchical protocol integer linear programming (ILP) recursive method

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The fast recursive computation of Tchebichef moment and its inverse transform based on Z-transform

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DIGITAL SIGNAL PROCESSING 2013年第5期23卷 1738-1746页

作者： Asli, Barmak Honarvar Shakibaei Paramesran, Raveendran Lim, Chern-Loon Univ Malaya Fac Engn Dept Elect Engn Kuala Lumpur 50603 Malaysia

The outputs of cascaded digital filters operating as accumulators are combined with a simplified Tchebichef polynomials to form Tchebichef moments (TMs). In this paper, we derive a simplified recurrence relationship to compute Tchebichef polynomials based on Z-transform properties. This paves the way for the implementation of second order digital filter to accelerate the computation of the Tchebichef polynomials. Then, some aspects of digital filter design for image reconstruction from TMs are addressed. The new proposed digital filter structure for reconstruction is based on the 2D convolution between the digital filter outputs used in the computation of the TMs and the impulse response of the proposed digital filter. They operate as difference operators and accordingly act on the transformed image moment sets to reconstruct the original image. Experimental results show that both the proposed algorithms to compute TMs and inverse Tchebichef moments (ITMs) perform better than existing methods in term of computation speed. (C) 2013 Elsevier Inc. All rights reserved.

关键词： Tchebichef moments recursive method Image reconstruction Cascaded digital filters Z-transform

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A Bilevel Optimization Model for Risk Assessment and Contingency Ranking in Transmission System Reliability Evaluation

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IEEE TRANSACTIONS ON POWER SYSTEMS 2017年第5期32卷 3803-3813页

作者： Ding, Tao Li, Cheng Yan, Chao Li, Fangxing Bie, Zhaohong Xi An Jiao Tong Univ State Key Lab Elect Insulat & Power Equipment Xian 710049 Shaanxi Peoples R China Univ Tennessee Dept Elect Engn & Comp Sci Knoxville TN 37996 USA

This paper presents a bilevel optimization model for the risk assessment of transmission systems. Specifically, the lower level model is expected to provide a generation redispatch by minimizing the total load shedding, and the upper-level model is to maximize the severity risk by constructing a binary optimization model to identify the worst N-k contingency. To further reduce the complexity of the proposed model, the logarithmic transformation and linearization techniques are utilized, leading to a general mixed integer linear programming. In addition, a recursive method is proposed for contingency ranking based on the bilevel optimization model. Compared with the benchmark analytic method, the proposed method does not need to enumerate every contingency, reducing the computational burden. In contrast to the traditional Monte Carlo Simulation method, the proposed method can give as precise a risk assessment result as the analytic method and has higher evaluation efficiency. Numerical results on three test systems verify the effectiveness of the proposed method.

关键词： bi-level optimization contingency ranking mixed integer programming power system reliability evaluation recursive method risk assessment

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Fast computation of Jacobi-Fourier moments for invariant image recognition

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PATTERN RECOGNITION 2015年第5期48卷 1836-1843页

作者： Upneja, Rahul Singh, Chandan Sri Guru Granth Sahib World Univ Dept Math Fatehgarh Sahib 140406 India Punjabi Univ Dept Comp Sci Patiala 147002 Punjab India

The Jacobi-Fourier moments (JFMs) provide a wide class of orthogonal rotation invariant moments (ORIMs) which are useful for many image processing, pattern recognition and computer vision applications. They, however, suffer from high time complexity and numerical instability at high orders of moment. In this paper, a fast method based on the recursive computation of radial kernel function of JFMs is proposed which not only reduces time complexity but also improves their numerical stability. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Jacobi-Fourier moments recursive method Numerical stability

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