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Robust and fast algorithm for estimating fundamental periodicity of jet engine modulation signals

IET RADAR SONAR AND NAVIGATION 2016年第7期10卷 1286-1294页

作者： Yong, Yang Woo Hoon, Park Ji Young, Song Won Hoon, Myung Noh Hanwha Thales Radar Res Ctr Seoul South Korea Agcy Def Dev Technol Ctr POB 35-3 Yuseong Daejeon South Korea Korea Adv Inst Sci & Technol Dept Elect Engn 335 Gwahangno Daejeon 305701 South Korea

Jet engine modulation (JEM), a modulation phenomenon induced by a rotating jet engine compressor, is a representative feature extracted from the radar for aircraft target recognition. In this study, the authors present a robust and fast algorithm for extracting the spool rate, which imparts fundamental periodicity to JEM signals. First, a wavelet decomposition with Meyer wavelet was applied to the analytic form of the JEM signal. Then, the decomposition components were combined to achieve a sufficient energy and minimise the mean of the JEM auto-correlation. Finally, the peak detection algorithm was employed for automatic estimation of the spool rate. Application results of measured JEM signals demonstrated that the proposed algorithm is effective for stable and accurate extraction of the jet engine information.

关键词： object recognition radar detection wavelet transforms feature extraction correlation methods jet engines radar target recognition compressors automatic spool rate estimation peak detection algorithm JEM auto-correlation decomposition components Meyer wavelet wavelet decomposition JEM signals spool rate extraction aircraft target recognition representative feature extraction rotating jet engine compressor jet engine modulation signals fundamental periodicity estimation fast algorithm robust algorithm

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A fast algorithm for depth migration by the Gaussian beam summation method

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JOURNAL OF GEOPHYSICS AND ENGINEERING 2017年第1期14卷 173-183页

作者： Gao, Zhenghui Sun, Jianguo Sun, Xu Wang, Xueqiu Sun, Zhangqing Liu, Zhiqiang Jilin Univ Coll Geoexplorat Sci & Technol Changchun 130026 Peoples R China Jilin Univ Engn Training Ctr Changchun 130026 Peoples R China

Depth migration by the Gaussian beam summation method has no limitation on the seismic acquisition configuration. In the past, this migration method applied the steepest descent approximation to reduce the dimension of the integrals over the ray parameters at the cost of a precision loss. However, the simplified formula was still in the frequency domain, thereby impairing the computational efficiency. We present a new fast algorithm which can increase the computational efficiency without losing precision. To develop the fast algorithm, we change the order of the integrals and treat the two innermost integrals as a couple of two-dimensional continuous functions with respect to the real and imaginary parts of the total traveltime. A couple of lookup tables corresponding to the values of the two innermost integrals are constructed at the sampling points. The results of the two innermost integrals at a certain imaging point can be obtained through interpolation in the two constructed lookup tables. Both the numerical analysis and examples validate the precision and efficiency of the fast algorithm. With the advantage of handling rugged topography, we apply the fast algorithm to the 2D Canadian Foothills velocity model.

关键词： depth migration Gaussian beam summation method fast algorithm lookup table

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fast algorithm FOR PREDICTION UNIT AND MODE DECISIONS OF INTRA DEPTH CODING IN 3D-HEVC 23

FAST ALGORITHM FOR PREDICTION UNIT AND MODE DECISIONS OF INT...

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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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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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fast algorithms for perturbed Toeplitz-plus-Hankel system based on discrete cosine transform and their applications

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JAPAN JOURNAL OF INDUSTRIAL AND APPLIED MATHEMATICS 2024年第1期41卷 567-583页

作者： Zhang, Xing Zheng, Yanpeng Jiang, Zhaolin Byun, Heejung Linyi Univ Sch Informat Sci & Technol Linyi 276000 Peoples R China Univ Suwon Coll Informat Technol Hwaseong Si 445743 South Korea Linyi Univ Sch Automat & Elect Engn Linyi 276000 Shandong Peoples R China Linyi Univ Sch Math & Stat Linyi 276000 Peoples R China

A class of perturbed Toeplitz-plus-Hankel matrices are studied in this paper. Firstly, we present two fast algorithms for computing the eigenvalues of a Toeplitz-plus-Hankel matrix which can be diagonalized by discrete cosine transform. Based on the diagonalization of the Toeplitz-plus-Hankel matrix, algorithms for fast Toeplitz-plus-Hankel matrix-vector multiplication and solving the Toeplitz-plus-Hankel system are given. Secondly, we propose two new algorithms with less computational time to solve the perturbed Toeplitz-plus-Hankel linear system. Thirdly, image encryption and decryption utilizing the proposed algorithms are shown. Finally, the effectiveness of our proposed algorithms is verified by numerical experiments.

关键词： fast algorithm Toeplitz-plus-Hankel system Symmetric centrosymmetric matrix Discrete cosine transform

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A fast algorithm of GNSS-R Signal Processing Based on DBZP

A Fast Algorithm of GNSS-R Signal Processing Based on DBZP

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第八届中国卫星导航学术年会

作者： Lin Han Yansong Meng Yanguang Wang Xingyuan Han Institute of satellite navigation &ISL technology Academy of space electrical information technology

ISBN: (纸本)9789811045875

An important observation of GNSS-R is Delay-Doppler mapping(DDM). According to the requirement of GNSS-R signal real-time processing, a fast processing algorithm of GNSS-R signal based on double block zero padding(DBZP) and frequency domain rotation transformation is proposed for DDM generation. The reflected data is blocked and then correlated, which avoids the FFT calculation with too long points. The block and zero padding operations not only guarantee the full search of the pseudo code phase, but also avoid the repetitive calculation. In the frequency domain, the correlation results at different Doppler frequencies are approximated by the rotation transformation method, which avoids a large number of carrier multiplication operations and effectively reduces the computational burden. The computational burden and computational loss of parallel code phase correlation algorithm and fast algorithm are analyzed. Finally, the UK-DMC satellite-borne reflected data are processed by two algorithms and the simulation time-consuming and processing results were compared. The results show that the fast algorithm greatly shortens the DDM generation time and the loss of the processing result is small.

关键词： GNSS-R GNSS Reflected Signal Processing DBZP fast algorithm DDM

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fast algorithms for Computing the Hilbert Transform of a Given Function with Cubic Splines

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COMMUNICATIONS ON APPLIED MATHEMATICS AND COMPUTATION 2024年 1-14页

作者： Yu, Bo Du, Jiaxin Qin, Xiaoxiao China Three Gorges Univ Coll Sci Three Gorges Math Res Ctr Yichang 443002 Hubei Peoples R China

It is important to compute the Hilbert transform of a given function defined on a finite interval. In 2013, Micchelli and his collaborators proposed a fast algorithm, which is called the Hilbert spline transform, to calculate the Hilbert transform of a given function on a finite interval with the computational complexity O(nlogn)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$O(n\log n)$$\end{document}, where the spline knots were chosen to be the midpoints of sampling points. A natural question is that, whether or not the spline knots can be chosen to be the same as the sampling points. This paper gives a positive answer to this question. Besides, the analytic expression of the Hilbert transform of B-splines of any order is also established. Furthermore, the problem of how to choose spline coefficients, using the quasi-interpolation method or interpolation method, is also considered, although both make sure an optimal approximation order. Several interesting numerical examples are implemented and compared with most of the existing methods. Numerical results show that the proposed algorithm has a relatively high computational accuracy as well as a relatively low computational complexity.

关键词： The Hilbert transform The Hilbert spline transform Quasi-interpolation cubic spline approximation Interpolation cubic spline approximation fast algorithm

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A fast algorithm for Overlapping Community Detection 8

A Fast Algorithm for Overlapping Community Detection

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8th International Conference on Information and Knowledge Technology (IKT)

作者： Elyasi, Mostafa Meybodi, Mohammadreza Rezvanian, Alireza Haeri, Maryam Amir Amirkabir Univ Technol Tehran Polytech Dept Comp Engn & IT Tehran Iran

ISBN: (纸本)9781509043354

Nowadays, the emergence of online social networks have empowered people to easily share information and media with friends. Interacting users of social networks with similar users and their friends form community structures of networks. Uncovering communities of the online users in social networks plays an important role in network analysis with many applications such as finding a set of expert users, finding a set of users with common activities, finding a set of similar people for marketing goals, to mention a few. Although, several algorithms for disjoint community detection have been presented in the literature, online users simultaneously interact with their friends having different interests. Also users are able to join more than one group at the same time which leads to the formation of overlapping communities. Thus, finding overlapping communities can realize a realistic analysis of networks. In this paper, we propose a fast algorithm for overlapping community detection. In the proposed algorithm, in the first phase, the Louvain method is applied to the given network and in the second phase a belonging matrix is updated where an each element of belonging matrix determines how much a node belongs to a community. Finally, some of the found communities are merged based on the modularity measure. The performance of the proposed algorithm is studied through the simulation on the popular networks which indicates that the proposed algorithm outperforms several well-known overlapping community detection algorithms.

关键词： community detection overlapping communities social network analysis belonging matrix larg networks fast algorithm

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A fast sequentially-decoupled matrix-decomposed algorithm for variable-order time-fractional optimal control and error estimate

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JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 2025年 469卷

作者： Jia, Jinhong Wang, Hong Zhou, Zhaojie Zheng, Xiangcheng Shandong Normal Univ Sch Math & Stat Jinan 250358 Shandong Peoples R China Univ South Carolina Dept Math Columbia SC 29208 USA Shandong Univ Sch Math State Key Lab Cryptog & Digital Econ Secur Jinan 250100 Shandong Peoples R China

We introduce a fast sequentially decoupled matrix-decomposed approach tailored for optimal control problems constrained by a Caputo time-fractional diffusion equation featuring hidden memory and space-dependent order. Our method unveils a quasi translation-invariant structure adept at managing spatio-temporal dependencies. This structure not only slashes the computational burden of coefficients from O(MN2) to O(MNlnN), where M and N denote the spatial degrees of freedom and temporal steps in discretization, respectively, but also untangles the coupling between the space-dependent order and the inner product of the finite element method. Furthermore, we derive a swift matrix-decomposed algorithm designed to tackle the first-order optimality system, yielding a marked improvement in computational cost from O(MN2) to O(MN ln3 N) in each iteration. We substantiate our approach through rigorous numerical analysis and present numerical experiments to validate the theoretical underpinnings.

关键词： Variable-order fractional derivative fast algorithm Optimal control

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A fast Lanczos-based hierarchical algorithm for tensor ring decomposition

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SIGNAL PROCESSING 2025年 227卷

作者： Sun, Cheng-Wei Huang, Ting-Zhu Dou, Hong-Xia Xu, Ting Deng, Liang-Jian Univ Elect Sci & Technol China Sch Math Sci Chengdu 611731 Sichuan Peoples R China Xihua Univ Sch Sci Chengdu 610039 Sichuan Peoples R China

Tensor ring (TR) decomposition has made remarkable achievements in numerous high-order data processing tasks. However, the current alternating least squares (ALS)- and singular value decomposition (SVD)-based algorithms for TR decomposition, i.e., TR-ALS and TR-SVD, especially the former, are computationally expensive, making them unfriendly for large-scale data processing. This paper adopts three strategies to propose a novel fast TR decomposition algorithm: (1) Use a more efficient Lanczos bidiagonalization algorithm SVD to generate the TR core tensors. (2) Exploit the hierarchical strategy to generate the TR core tensors parallel. (3) Employ new reshaping and unfolding operations to reduce the dimensionality of the data to generate TR core tensors. By incorporating these three strategies, we propose the TR-HLanczos algorithm for fast TR decomposition. This algorithm seamlessly produces the TR core tensors through the Lanczos bidiagonalization algorithm in a hierarchical manner. The effectiveness of the proposed TR-HLanczos algorithm is demonstrated through experimental results on both highly oscillatory functions and real-world datasets. For instance, when dealing with data of size 505, 5 , TR-HLanczos is nearly 561 times and 18 times faster algorithms based on ALS and SVD, respectively.

关键词： Tensor ring decomposition Lanczos bidiagonalization algorithm fast algorithm

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