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23rd IEEE International Conference on Image Processing (ICIP)

作者： Guo, Ruixue He, Gang Li, Yunsong Wang, Keyan Xidian Univ Sch Telecommun Engn Xian Shaanxi Peoples R China

ISBN: (纸本)9781467399616

As the state-of-the-art video coding standard for 3D video, the 3D video extension of High Efficiency Video Coding (3D-HEVC) compresses the multi-view texture videos plus depth maps. The intra depth coding consumes huge computational complexity due to the added depth modeling modes (DMMs) and its new complex processing flow. This paper proposes a fast algorithm to reduce the complexity for prediction unit (PU) and mode decisions for intra depth coding. Firstly, the early PU splitting and pruning methods are proposed to fast decide the PU size, based on the intra depth coding flow. Secondly, by analyzing the relationship between DMMs and Planar mode, a fast algorithm is used to skip the mode decision under the certain condition. Experimental results show our proposed methods together reduce 56.32% and 50.12% computational complexity for depth map and total video coding, while the performance loss is only 1.42% BD-rate increasing.

关键词： 3D-HEVC Depth maps PU decision Mode decision fast algorithm

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NEW fast algorithm FOR TWO-DIMENSIONAL DISCRETE FOURIER-TRANSFORM DFT(2N-2)

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ELECTRONICS LETTERS 1989年第1期25卷 21-22页

作者： MA, WZ YANG, DK South China Univ. of Technol. Guangzhou China

Presents a new fast algorithm for computing the two-dimensional discrete Fourier transform DFT(2n; 2) using the fast discrete cosine transform algorithm. The algorithm has a lower number of multiplications and additions compared with other published algorithms for computing the two-dimensional DFT. Because it uses only real multiplications, the algorithm is more suitable for real input data.

关键词： discrete cosine transform algorithm fast Fourier transforms fast algorithm number of additions number of multiplications signal processing subroutines two-dimensional DFT two-dimensional discrete Fourier transform

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A fast algorithm for the simulation of arterial pulse waves

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JOURNAL OF COMPUTATIONAL PHYSICS 2016年 314卷 450-464页

作者： Du, Tao Hu, Dan Cai, David Shanghai Jiao Tong Univ Inst Nat Sci Dept Math Shanghai 200030 Peoples R China Shanghai Jiao Tong Univ MOE LSC Shanghai 200030 Peoples R China NYU Courant Inst Math Sci New York NY USA NYU Ctr Neural Sci New York NY 10003 USA New York Univ Abu Dhabi NYUAD Inst POB 129188 Abu Dhabi U Arab Emirates

One-dimensional models have been widely used in studies of the propagation of blood pulse waves in large arterial trees. Under a periodic driving of the heartbeat, traditional numerical methods, such as the Lax-Wendroff method, are employed to obtain asymptotic periodic solutions at large times. However, these methods are severely constrained by the CFL condition due to large pulse wave speed. In this work, we develop a new numerical algorithm to overcome this constraint. First, we reformulate the model system of pulse wave propagation using a set of Riemann variables and derive a new form of boundary conditions at the inlet, the outlets, and the bifurcation points of the arterial tree. The new form of the boundary conditions enables us to design a convergent iterative method to enforce the boundary conditions. Then, after exchanging the spatial and temporal coordinates of the model system, we apply the Lax-Wendroff method in the exchanged coordinate system, which turns the large pulse wave speed from a liability to a benefit, to solve the wave equation in each artery of the model arterial system. Our numerical studies show that our new algorithm is stable and can perform similar to 15 times faster than the traditional implementation of the Lax-Wendroff method under the requirement that the relative numerical error of blood pressure be smaller than one percent, which is much smaller than the modeling error. (C) 2016 Elsevier Inc. All rights reserved.

关键词： Blood pulse wave Riemann variables Lax-Wendroff method Large wave speed fast algorithm

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Uniform convergence of a fast algorithm for Cauchy singular integral equations

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LINEAR ALGEBRA AND ITS APPLICATIONS 1998年 276卷 327-347页

作者： Junghanns, P Luther, U Tech Univ Chemnitz Zwickau Fak Math D-09107 Chemnitz Germany

Error estimates for a fast algorithm applied to a Cauchy singular integral equation are proved in weighted uniform norms. This algorithm is essentially based on the application of discrete sine transformations. Numeri... 详细信息

关键词： Cauchy singular integral equations fast algorithm discrete sine and cosine transformations

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A numerical study of pulsatile blood flow in an eccentric catheterized artery using a fast algorithm

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JOURNAL OF ENGINEERING MATHEMATICS 2002年第1期42卷 1-22页

作者： Daripa, P Dash, RK Texas A&M Univ Dept Math College Stn TX 77843 USA

The pulsatile blood flow in an eccentric catheterized artery is studied numerically by making use of an extended version of the fast algorithm of Borges and Daripa [J. Comp. Phys., 2001]. The mathematical model involves the usual assumptions that the arterial segment is straight, the arterial wall is rigid and impermeable, blood is an incompressible Newtonian fluid, and the flow is fully developed. The flow rate (flux) is considered as a periodic function of time (prescribed). The axial pressure gradient and velocity distribution in the eccentric catheterized artery are obtained as solutions of the problem. Through the computed results on axial pressure gradient, the increases in mean pressure gradient and frictional resistance in the artery due to catheterization are estimated. These estimates can be used to correct the error involved in the measured pressure gradients using catheters.

关键词： Poisson solver fast algorithm pulsatile blood flow eccentric catheterized artery

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Thin interbed AVA inversion based on a fast algorithm for reflectivity

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ACTA GEOPHYSICA 2020年第4期68卷 1007-1020页

作者： Yang, Zhen Lu, Jun Chinese Acad Sci Inst Geol & Geophys Key Lab Earth & Planetary Phys Beijing 100029 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China China Univ Geosci Sch Geophys & Informat Technol Beijing 100083 Peoples R China

Zoeppritz equations form the theoretical basis of most existing amplitude variation with incident angle (AVA) inversion methods. Assuming that only primary reflections exist, that is, the multiples are fully suppressed and the transmission loss and geometric spreading are completely compensated for, Zoeppritz equations can be used to solve for the elastic parameters of strata effectively. However, for thin interbeds, conventional seismic data processing technologies cannot suppress the internal multiples effectively, nor can they compensate for the transmission loss accurately. Therefore, AVA inversion methods based on Zoeppritz equations or their approximations are not applicable to thin interbeds. In this study, we propose a prestack AVA inversion method based on a fast algorithm for reflectivity. The fast reflectivity method can compute the full-wave responses, including the reflection, transmission, mode conversion, and internal multiples, which is beneficial to the seismic inversion of thin interbeds. A further advantage of the fast reflectivity method is that the partial derivatives of the reflection coefficient with respect to the elastic parameters can be expressed as analytical solutions. Based on the Gauss-Newton method, we construct the objective function and model-updating formula considering sparse constraint, where the Jacobian matrix takes the form of an analytical solution, which can significantly accelerate the inversion convergence. We validate our inversion method using numerical examples and field seismic data. The inversion results demonstrate that the fast reflectivity-based inversion method is more effective for thin interbed models in which the wave-propagation effects, such as interval multiples, are difficult to eliminate.

关键词： Amplitude variation with incident angle Inversion Thin interbed fast algorithm Reflectivity method

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fast algorithm of (k, k-1) Type Discrete Walsh-Haar Transformation and Application in Image Edge Detection

Fast Algorithm of (k, k-1) Type Discrete Walsh-Haar Transfor...

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7th Symposium on Multispectral Image Processing and Pattern Recognition (MIPPR) - Remote Sensing Image Processing, Geographic Information Systems, and Other Applications

作者： Lu, Li Shi, Bao-Chang Huazhong Univ Sci & Technol Sch Software Engn Wuhan 430074 Hubei Peoples R China Huazhong Univ Sci & Technol Sch Math & Stat Wuhan 430074 Peoples R China

ISBN: (纸本)9780819485809

Walsh-Haar function system that was first introduced by us is a new kind of function systems, and has a good global / local property. This function system is called Walsh ordering function system since its generation kernel functions belong to Walsh ordering Walsh function system. We worked out a recursive property of the matrix WHKRm+1 corresponding to the first (KRm+1) Walsh-Haar functions in Walsh-Haar function system, and proved that Walsh-Haar function system is perfect and orthogonal similar to Walsh function system and Haar function system. Thus, discrete Walsh-Haar transformation (DW-HT) is an orthogonal transformation that can be widely used in signal processing. In this paper, using the recursive property of the matrix WHKRm+1 and the fast algorithm of discrete Walsh transformation in Walsh ordering, we have designed a fast algorithm of Walsh ordering (k, k-1) type DW-HT based on the bisection technique. As one of its applications, we use it to detect image edges. Compare with some edge-detecting methods, the method in this paper detects more details of image edge. The idea and method used to design the fast algorithm in this paper can be used to design fast algorithms of other ordering (k, k-1) type DW-HTs and other discrete orthogonal transformations.

关键词： Walsh-Haar matrix discrete Walsh-Haar transformation the bisection technique fast algorithm edge detection

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A fast algorithm for the inversion of general Toeplitz matrices

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COMPUTERS & MATHEMATICS WITH APPLICATIONS 2005年第5-6期50卷 741-752页

作者： Martinsson, PG Rokhlin, V Tygert, M Yale Univ Dept Math New Haven CT 06520 USA

We propose a "fast" algorithm for the construction of a data-sparse inverse of a general Toeplitz matrix. The computational cost for inverting an N x N Toeplitz matrix equals the cost of four length-N FFTs plus an O(N)-term. This cost should be compared to the O(N log(2) N) cost of previously published methods. Moreover, while those earlier methods are based on algebraic considerations, the procedure of this paper is analysis-based;as a result, its stability does not depend on the symmetry and positive-definiteness of the matrix being inverted. The performance of the scheme is illustrated with numerical examples. (c) 2005 Elsevier Ltd. All rights reserved.

关键词： Toeplitz matrix fast algorithm direct inversion

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A Pre-splitting Green's Function based Hybrid fast algorithm for Multiscale Problems

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APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL 2023年第9期38卷 652-666页

作者： Zhu, Guang-Yu Li, Wei-Dong Sha, Wei E. I. Zhou, Hou-Xing Hong, Wei Zhejiang Univ Coll Informat Sci & Elect Engn Hangzhou 310027 Peoples R China Southeast Univ Frontiers Sci Ctr Mobile Informat Commun & Secur State Key Lab Millimeter Waves Nanjing 210096 Peoples R China

- Based on the splitting form of the Green's function, a hybrid fast algorithm is proposed for efficient analysis of multiscale problems. In this algorithm, the Green's function is a priori split into two parts: a spectrally band-limited part and a spatially localized part. Then, the fast Fourier transforms (FFT) utilizing the global Cartesian grid and the matrix compression method aided by an adaptive octree grouping are implemented for these two parts, respectively. Compared with the traditional methods which only employ the FFT for acceleration, the proposed hybrid fast algorithm is capable of maintaining low memory consumption in multiscale the proposed algorithm does not need cumbersome geometric treatment to implement the hybridization, and can be established in a concise and straightforward manner. performance of proposed hybrid fast algorithm.

关键词： fast algorithm fast Fourier transform Green's function matrix compression multiscale prob- lems

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fast algorithm for Completion State Calculating of Wire Rope Cable Bridge 8th

Fast Algorithm for Completion State Calculating of Wire Rope...

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8th International Conference on Civil Engineering (ICCE)

作者： Feng, Yang Song, Dan Li, Minghui Power China Northwest Engn Corp Ltd Xian 710065 Peoples R China

ISBN: (纸本)9789811912603;9789811912597

When determining the completion state of the main cable of a cable-way bridge, although the catenary theory can accurately consider the nonlinear mechanical effect of the cable, the iterative calculation is cumbersome and not convenient for engineering applications. Although the calculation based on the parabola theory is simple, the calculation accuracy for long cables is low. In this paper, based on catenary theory and considering the calculation accuracy and avoiding iterative calculation, a fast algorithm for the completion state of the main cable of the wire rope cableway bridge is proposed. The results show that the bridge state can be quickly and accurately determined by approximating the horizontal component of the cable tension and avoiding multiple iterative calculations. The proposed algorithm can be used in engineering design and construction.

关键词： fast algorithm Wire rope Cable Bridge Catenary theory Parabola theory

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