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A subspace algorithm to Mitigate Energy Unknown RFI for Synthetic Aperture Interferometric Radiometer

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2020年第1期58卷 227-237页

作者： Jin, Rong Li, Qingxia Liu, Hang Huazhong Univ Sci & Technol Sch Elect Informat & Commun Wuhan 430074 Peoples R China Beijing Bytedance Technol Co Beijing Peoples R China

Radio frequency interferences (RFIs) are present in the data collected by a synthetic aperture interferometric radiometer (SAIR), and these would seriously affect the retrieval of brightness temperature (BT), if not properly handled. Due to the truncated Fourier characteristic, RFIs create ripples that extend over a large set of pixels of the whole image, which is difficult to cancel out their impacts at the BT domain. The current strategy relies on removing the unwanted sources at the visibility level (Fourier domain) with a set of synthetic visibilities of the RFI sources for a given snapshot. However, a major problem is that, as unauthorized emissions, the energies of RFIs are typically unknown and the estimation to the sources' temperature could be inaccurate without credible prior information. In this article, a subspace algorithm is proposed to handle the RFI mitigation problem by exploiting RFI's point-source characteristic, where the visibilities related to the RFIs are excluded from that of the BT scene through an orthogonal design without the need of knowing the sources' power. Both the numerical simulations and the proof-of-concept experiment validate the theoretical correctness and the practical effectiveness of our proposed method.

关键词： Microwave radiometry Estimation Apertures Antenna measurements Frequency estimation Image reconstruction Energy unknown radio frequency interference (RFI) RFI mitigation subspace algorithm synthetic aperture interferometric radiometer (SAIR)

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Detecting a hyperbolic quadratic eigenvalue problem by using a subspace algorithm

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NUMERICAL algorithmS 2020年第2期83卷 767-787页

作者： Pandur, Marija Miloloza Univ Osijek Dept Math Trg Ljudevita Gaja 6 Osijek 31000 Croatia

We consider the quadratic eigenvalue problem (QEP) Q(lambda)x := (lambda M-2 + lambda D + K)x = 0. A Hermitian QEP is hyperbolic if M is positive definite and (x(H)Dx)(2) - 4(x(H)Mx)(x(H)Kx) > 0 for all nonzero vectors x. Although there exist many algorithms for detecting hyperbolicity, most of them are not suitable for large QEPs. Motivated by this, we propose a new basic subspace algorithm for detecting large hyperbolic QEPs. Furthermore, we propose a specialized algorithm and its preconditioned variant. Our algorithms can be easily adapted to detect a large overdamped QEP (a hyperbolic QEP with D positive definite and K positive semidefinite). Numerical experiments demonstrate the efficiency of our specialized algorithms.

关键词： Quadratic eigenvalue problem Hyperbolic Overdamped Gap subspace algorithm LOBPeCG

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subspace algorithm for Identifying Bilinear Repetitive Processes with Deterministic Inputs

Subspace Algorithm for Identifying Bilinear Repetitive Proce...

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European Control Conference

作者： José A. Ramos Eric Rogers Paulo Lopes dos Santos Teresa Perdicoúlis Nova Southeastern University College of Engineering and Computing 3301 College Avenue Fort Lauderdale FL 33314 School of Electronics and Computer Science University of Southampton Southampton S017 1BJ UK Faculty of Engineering University of Porto Rua dos Bragas s/n 4200-465 Porto Portugal ISR - Coimbra and Department of Mathematics University of Tras-os-Montes 5001-801 Vila Real Portugal

ISBN: (纸本)9781509025923

In this paper we introduce a bilinear repetitive process and present an iterative subspace algorithm for its identification. The advantage of the proposed approach is that it overcomes the "curse of dimensionality", a hurdle commonly encountered with classical bilinear subspace identification algorithms. Simulation results show that the algorithm converges quickly and provides new alternatives for modeling/identifying nonlinear repetitive processes.

关键词： subspace algorithm Identifying Bilinear Repetitive Processes Deterministic Inputs

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A Penalized subspace Strategy for Solving Large-Scale Constrained Optimization Problems 29

A Penalized Subspace Strategy for Solving Large-Scale Constr...

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29th European Signal Processing Conference (EUSIPCO)

作者： Martin, Segolene Chouzenoux, Emilie Pesquet, Jean-Christophe Univ Paris Saclay INRIA Cent Supelec Ctr Vis Numer Gif Sur Yvette France

ISBN: (纸本)9789082797060

Many data science problems can be efficiently addressed by minimizing a cost function subject to various constraints. In this paper a new method for solving large-scale constrained differentiable optimization problems is proposed. To account efficiently for a wide range of constraints, our approach embeds a subspace algorithm into an exterior penalty framework. The subspace strategy, combined with a Majoration-Minimization step search, takes great advantage of the smoothness of the penalized cost function. Assuming that the latter is convex, the convergence of our algorithm to a solution of the constrained optimization problem is proved. Numerical experiments carried out on a large-scale image restoration application show that the proposed method outperforms state-of-the-art algorithms in terms of computational time.

关键词： Differentiable optimization Exterior penalty method Majoration-Minimization subspace algorithm Large-scale problems

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Capon-like method for direction of arrival estimation Using acoustics vector sensor

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APPLIED ACOUSTICS 2022年 197卷

作者： Chen, Feng Yang, Desen Zhang, Yi Li, Song Mo, Shiqi Harbin Engn Univ Coll Underwater Acoust Engn Harbin 150001 Peoples R China Harbin Engn Univ Acoust Sci & Technol Lab Harbin 150001 Peoples R China Harbin Engn Univ Key Lab Marine Informat Acquisit & Secur Minist Ind & Informat Technol Harbin 150001 Peoples R China

Acoustic vector sensor (AVS) is a kind of sensor widely used in underwater detection. This study found that due to inconsistent received noise power, the acoustic vector sensor generates virtual sources, which could affect the subspace algorithm. To overcome this shortcoming, a Direction-Of-Arrival (DOA) algo-rithm which is agnostic to the number of sources is proposed. Using the covariance matrix and the power of the scanning source, a reference matrix is constructed, and the maximum eigenvalue characteristics of the reference matrix at different angles are analyzed. Secondly, a novel eigenvalue arrangement is con-structed based on the conclusions. Thirdly, the influence of the relevant parameters on the performance of the proposed algorithm is analysed. Finally, the correctness of the theory and the algorithm is verified by the experimental simulation. (c) 2022 Published by Elsevier Ltd.

关键词： Acoustic vector sensor Virtual sources Noise power direction -of -arrival (DOA) subspace algorithm Signal eigenvalues Number of sources

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Road Roughness Modelling by Using Spectral Factorization Methods 16

Road Roughness Modelling by Using Spectral Factorization Met...

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16th International Conference on Control, Automation and Systems (ICCAS)

作者： Turkay, Semiha Akcay, Huseyin Anadolu Univ Dept Elect & Elect Engn Eskisehir Turkey

ISBN: (纸本)9788993215120

In this paper, road roughness model for the right and the left tracks are constructed by utilizing two methods. In the first method, from time-domain measurements the empirical auto and cross-power spectral densities of the left and the right tracks are estimated by using the Welch method. Next, the road roughness is decomposed into three stochastically independent random processes and the linear-shape filter parameters of the right and the left tracks are estimated via a recently developed subspace-based identification algorithm. In the second method, a multi-input/multi-output subspacebased identification algorithm is directly used, without employing spectral decomposition to derive the spatial-domain models of the right and the left tracks from the Welch power spectral density estimates. Profile measurements for a specific road section from the Long Term Pavement Performance archive of the University of Michigan Transportation Research Institute is used to demonstrate the successfull application of the subspace approach.

关键词： Road roughness parallel tracks power spectral density coherence estimation subspace algorithm

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Eastern Peninsula Malaysia Rainfall Model Identification using Balanced Stochastic Realization algorithm 5

Eastern Peninsula Malaysia Rainfall Model Identification usi...

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5th IEEE International Conference on Control System, Computing and Engineering (ICCSCE)

作者： Azhari, Fahimy Mohd-Mokhtar, Rosmiwati Univ Sains Malaysia Sch Elect & Elect Engn Engn Campus Nibong Tebal 14300 Pulau Pinang Malaysia

ISBN: (纸本)9781479982523

Rainfall forecasting is an important component of flood warning to the public especially in tropical climate region like Malaysia. The forecasts can be used to make decisions about whether warnings of floods should be issued to the general public in advance. In this research, this time series data of rainfall is firstly used to obtain the model using the system identification approach. Balanced Stochastic Realization (BSR) subspace algorithm is used to develop a rainfall model for Eastern Peninsula Malaysia site. The model is developed using a rainfall data obtained from Malaysia Meteorological Department (MMD). In this study, rainfall data in 2001 until 2005 from Kota Bharu station is used to simulate the model. The model is then used to estimate rainfall of the same station in 2006 until 2010. The results reveal good model performance and accuracy. The model is further used to estimate the neighboring state city of Kuantan and Kuala Terengganu. From analysis, the model also demonstrates good performance when tested to different data locations. The significant outcome from this study will able to assist further investigation on rainfall forecasting study in Malaysia, specifically, and tropical climatic region, generally.

关键词： Balanced stochastic realization subspace algorithm rainfall model

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Ionosphere phase decontamination method based on subspace in sky-wave OTHR

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ELECTRONICS LETTERS 2014年第24期50卷 1874-U241页

作者： Bo, Chao Gu, Hong Su, Weimin Chen, Jinli Nanjing Univ Sci & Technol Res Ctr Elect Engn Technol Nanjing 210094 Jiangsu Peoples R China Nanjing Univ Informat Sci & Technol Coll Elect & Informat Engn Nanjing 210044 Jiangsu Peoples R China

In general, ionosphere phase contamination can expand the Bragg peak of sea clutter and the echo signal from a target in sky-wave over-the-horizon radar (OTHR). By exploiting the subspace algorithm, an effective approach of ionosphere phase decontamination is proposed to solve the above-mentioned problems. In this new scheme, the stronger one of two spreading Bragg peaks is extracted by an adaptive sliding-window bandpass filter, and the instantaneous phase of the spreading Bragg peak is obtained by the subspace algorithm. Both the theoretical analysis and the experimental results of the real OTHR data have confirmed the feasibility of this new method.

关键词： HF radio propagation adaptive filters adaptive radar band-pass filters decontamination ionospheric electromagnetic wave propagation radar clutter radar signal processing adaptive sliding window bandpass filter echo signal ionosphere phase contamination ionosphere phase decontamination method sea clutter spreading Bragg peak extraction sky-wave OTHR sky-wave over-the-horizon radar target subspace algorithm

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Research on Thermal Multivariable System Identification Based on Living Operating Data

Research on Thermal Multivariable System Identification Base...

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2015 3rd International Conference on Machinery,Materials and Information Technology Applications(ICMMITA 2015)

作者： Shihe CHEN Xi ZHANG Jianguo DUAN Li ZHANG Xichun BAO Yuguang NIU Zhongwei LIN Electric Power Research Institute of Guangdong Power Grid Corporation School of control and computer engineering North China Electric power University

This paper introduces an identification algorithm for a thermal system with multi-variable closed-loops. First, a kind of subspace identification algorithm based on the principle component analysis(PCA) is analyzed. Next, the PCA is used to identify the parameters of the process, where dynamic model of coordinated control system(CCS) of power plant is obtained. Finally, an example for a subcritical drum boiler is used to illustrate the effectiveness of the introduced identification algorithm. The results demonstrate the contributions of the developed identification method to the closed-loops in thermal power plant

关键词： Thermal Power Plant Multi-variable Loop Closed-loop Identification Principle Component Analysis subspace algorithm

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Reachability and controllability of linear switched impulsive systems

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IET CONTROL THEORY AND APPLICATIONS 2013年第9期7卷 1294-1299页

作者： Liu, Chao Li, Chuandong Han, Qi Li, Chaojie Zhang, Qun Chongqing Univ Sci & Technol Sch Elect & Informat Engn Chongqing 401331 Peoples R China Southwest Univ Coll Elect & Informat Engn Chongqing 400715 Peoples R China Univ Ballarat Mt Helen Sch Sci Informat Technol & Engn Mt Helen Vic 3350 Australia Natl Univ Singapore NUS Grad Sch Integrat Sci & Engn NGS Singapore 117456 Singapore

This study investigates the reachability and controllability of linear switched impulsive systems in which impulsive component is independent of switching among different subsystems. Some crucial geometrical criteria are established. The authors present the fact that the reachable sets and the controllable sets may not be subspaces, if impulsive matrices are singular. While impulsive matrices are reversible, the reachable and controllable subspaces can be determined by two proposed subspace algorithms. The authors also point out that the reachable or controllable subspace is an invariant subspace of the considered systems. Finally, two simple corresponding examples are discussed to illustrate the correctness and effectiveness of the proposed theoretical results.

关键词： controllability linear systems matrix algebra reachability analysis time-varying systems reachability controllability linear switched impulsive system impulsive component impulsive matrix subspace algorithm invariant subspace

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