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Reinforced dynamics for enhanced sampling in large atomic and molecular systems

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arXiv 2017年

作者： Zhang, Linfeng Wang, Han Weinan, E. Program in Applied and Computational Mathematics Princeton University PrincetonNJ08544 United States Institute of Applied Physics and Computational Mathematics Fenghao East Road 2 Beijing100094 China CAEP Software Center for High Performance Numerical Simulation Huayuan Road 6 Beijing100088 China Department of Mathematics and Program in Applied and Computational Mathematics Princeton University PrincetonNJ08544 United States Beijing Institute of Big Data Research Beijing100871 China

A new approach for efficiently exploring the configuration space and computing the free energy of large atomic and molecular systems is proposed, motivated by an analogy with reinforcement learning. There are two major components in this new approach. Like metadynamics, it allows for an efficient exploration of the configuration space by adding an adaptively computed biasing potential to the original dynamics. Like deep reinforcement learning, this biasing potential is trained on the fly using deep neural networks, with data collected judiciously from the exploration and an uncertainty indicator from the neural network model playing the role of the reward function. Parameterization using neural networks makes it feasible to handle cases with a large set of collective variables. This has the potential advantage that selecting precisely the right set of collective variables has now become less critical for capturing the structural transformations of the system. The method is illustrated by studying the full-atom, explicit solvent models of alanine dipeptide and tripeptide, as well as the system of a polyalanine-10 molecule with 20 collective variables. Copyright © 2017, The Authors. All rights reserved.

关键词： Wave functions

Quantum anomalous Hall insulator phase in asymmetrically functionalized germanene

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Physical Review B 2017年第16期96卷 165426-165426页

作者： Chia-Hsiu Hsu Yimei Fang Shunqing Wu Zhi-Quan Huang Christian P. Crisostomo Yu-Ming Gu Zi-Zhong Zhu Hsin Lin Arun Bansil Feng-Chuan Chuang Li Huang Department of Physics Southern University of Science and Technology Shenzhen Guangdong 518055 China Department of Physics National Sun Yat-Sen University Kaohsiung 804 Taiwan Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices Department of Physics Xiamen University Xiamen 361005 China Institute of Theory Physics and Astrophysics Xiamen University Xiamen 361005 China Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry Xiamen 361005 China Centre for Advanced 2D Materials and Graphene Research Centre National University of Singapore Singapore 117546 Department of Physics National University of Singapore Singapore 117542 Department of Physics Northeastern University Boston Massachusetts 02115 USA Multidisciplinary and Data Science Research Center National Sun Yat-Sen University Kaohsiung 804 Taiwan

Using first-principles computations, we discuss topological properties of germanene in buckled as well as planar honeycombs with asymmetric passivation via hydrogen and nitrogen (GeHN) atoms. GeHN in the planar structure is found to harbor a quantum anomalous Hall (QAH) insulator phase. Our analysis indicates that the buckled GeHN also possesses a QAH phase under tensile strain. We computed the associated Chern numbers and edge states to confirm the presence of the QAH state. In particular, chiral edge bands connecting conduction and valence bands were found at the edges of a planar zigzag GeHN nanoribbon. By considering a range of buckling distances, we demonstrate how the system undergoes the transition from the trivial to the QAH phase between the buckled and planar structures. Finally, we show CdTe(111) to be a suitable substrate for supporting buckled germanene in the QAH phase. Our results suggest that functionalized germanene could provide a robust QAH-based platform for spintronics applications.

关键词： Edge states First-principles calculations Quantum anomalous Hall effect Topological materials Germanene

Gravitational Test beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole

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Physical Review Letters 2020年第14期125卷 141104-141104页

作者： Dimitrios Psaltis Lia Medeiros Pierre Christian Feryal Özel Kazunori Akiyama Antxon Alberdi Walter Alef Keiichi Asada Rebecca Azulay David Ball Mislav Baloković John Barrett Dan Bintley Lindy Blackburn Wilfred Boland Geoffrey C. Bower Michael Bremer Christiaan D. Brinkerink Roger Brissenden Silke Britzen Dominique Broguiere Thomas Bronzwaer Do-Young Byun John E. Carlstrom Andrew Chael Chi-kwan Chan Shami Chatterjee Koushik Chatterjee Ming-Tang Chen Yongjun Chen Ilje Cho John E. Conway James M. Cordes Geoffrey B. Crew Yuzhu Cui Jordy Davelaar Mariafelicia De Laurentis Roger Deane Jessica Dempsey Gregory Desvignes Jason Dexter Ralph P. Eatough Heino Falcke Vincent L. Fish Ed Fomalont Raquel Fraga-Encinas Per Friberg Christian M. Fromm Charles F. Gammie Roberto García Olivier Gentaz Ciriaco Goddi José L. Gómez Minfeng Gu Mark Gurwell Kazuhiro Hada Ronald Hesper Luis C. Ho Paul Ho Mareki Honma Chih-Wei L. Huang Lei Huang David H. Hughes Makoto Inoue Sara Issaoun David J. James Buell T. Jannuzi Michael Janssen Wu Jiang Alejandra Jimenez-Rosales Michael D. Johnson Svetlana Jorstad Taehyun Jung Mansour Karami Ramesh Karuppusamy Tomohisa Kawashima Garrett K. Keating Mark Kettenis Jae-Young Kim Junhan Kim Jongsoo Kim Motoki Kino Jun Yi Koay Patrick M. Koch Shoko Koyama Michael Kramer Carsten Kramer Thomas P. Krichbaum Cheng-Yu Kuo Tod R. Lauer Sang-Sung Lee Yan-Rong Li Zhiyuan Li Michael Lindqvist Rocco Lico Jun Liu Kuo Liu Elisabetta Liuzzo Wen-Ping Lo Andrei P. Lobanov Colin Lonsdale Ru-Sen Lu Jirong Mao Sera Markoff Daniel P. Marrone Alan P. Marscher Iván Martí-Vidal Satoki Matsushita Yosuke Mizuno Izumi Mizuno James M. Moran Kotaro Moriyama Monika Moscibrodzka Cornelia Müller Gibwa Musoke Alejandro Mus Mejías Hiroshi Nagai Neil M. Nagar Ramesh Narayan Gopal Narayanan Iniyan Natarajan Roberto Neri Aristeidis Noutsos Hiroki Okino Héctor Olivares Tomoaki Oyama Daniel C. M. Palumbo Jongho Park Nimesh Patel Ue-Li Pen Vincent Piétu Richard Plambeck Aleksandar PopStefanija Ben Prather Jorge A. Preciado-López Venkatessh Ramak Steward Observatory and Department of Astronomy University of Arizona 933 North Cherry Avenue Tucson Arizona 85721 USA School of Natural Sciences Institute for Advanced Study 1 Einstein Drive Princeton New Jersey 08540 USA National Radio Astronomy Observatory 520 Edgemont Road Charlottesville Virginia 22903 USA Massachusetts Institute of Technology Haystack Observatory 99 Millstone Road Westford Massachusetts 01886 USA National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Black Hole Initiative at Harvard University 20 Garden Street Cambridge Massachusetts 02138 USA Instituto de Astrofísica de Andalucía-CSIC Glorieta de la Astronomía s/n E-18008 Granada Spain Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 D-53121 Bonn Germany Institute of Astronomy and Astrophysics Academia Sinica 11F of Astronomy-Mathematics Building AS/NTU No. 1 Sec. IV Roosevelt Road Taipei 10617 Taiwan Republic of China Departament d’Astronomia i Astrofísica Universitat de València C. Dr. Moliner 50 E-46100 Burjassot València Spain Observatori Astronmic Universitat de València C. Catedrático José Beltrán 2 E-46980 Paterna València Spain Center for Astrophysics–Harvard & Smithsonian 60 Garden Street Cambridge Massachusetts 02138 USA East Asian Observatory 660 North A’ohoku Place Hilo Hawaii 96720 USA Nederlandse Onderzoekschool voor Astronomie (NOVA) P.O. Box 9513 2300 RA Leiden Netherlands Institute of Astronomy and Astrophysics Academia Sinica 645 North A’ohoku Place Hilo Hawaii 96720 USA Institut de Radioastronomie Millimétrique 300 rue de la Piscine F-38406 Saint Martin d’Hères France Department of Astrophysics Institute for Mathematics Astrophysics and Particle Physics (IMAPP) Radboud University P.O. Box 9010 6500 GL Nijmegen Netherlands Korea Astronomy and Space Science Institute Daedeok-daero 776 Yuseong-gu Daejeon 34055 Republic of Korea University of Science and Technology Gajeong-ro 217 Yuseong-gu Daejeon 34113 Re

The 2017 Event Horizon Telescope (EHT) observations of the central source in M87 have led to the first measurement of the size of a black-hole shadow. This observation offers a new and clean gravitational test of the black-hole metric in the strong-field regime. We show analytically that spacetimes that deviate from the Kerr metric but satisfy weak-field tests can lead to large deviations in the predicted black-hole shadows that are inconsistent with even the current EHT measurements. We use numerical calculations of regular, parametric, non-Kerr metrics to identify the common characteristic among these different parametrizations that control the predicted shadow size. We show that the shadow-size measurements place significant constraints on deviation parameters that control the second post-Newtonian and higher orders of each metric and are, therefore, inaccessible to weak-field tests. The new constraints are complementary to those imposed by observations of gravitational waves from stellar-mass sources.

关键词： Astrophysical studies of gravity Classical black holes Experimental studies of gravity Astronomical black holes

Small world yields optimal public goods in presence of both altruistic and selfish cooperators

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arXiv 2017年

作者： Cui, Pengbi Wu, Zhi-Xi Zhou, Tao Web Sciences Center University of Electronic Science and Technology of China Chengdu611731 China Big Data Research Center Univesrsity of Electronic Science and Technology of China Chengdu611731 China Institute of Computational Physics and Complex Systems Lanzhou University Lanzhou Gansu730000 China Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education Lanzhou University Lanzhou Gansu730000 China

Empirical studies have shown that individuals' behaviors are largely influenced by social conformity, including punishment. However, a coevolutionary theoretical framework that takes into account effects of conformity on individuals' punishment behaviors has not been put forward yet. Herein we propose a coevolutionary game model to extend the theory of cooperation with conformity in spatial public goods game by considering pool punishment, as well as two converse feedback modes of conformity that strongly affect cooperators' punishment behaviors. We focus on how different parameters and spatial structures govern evolutionary dynamics on three different kinds of networks by employing mean-field analysis based on replicator dynamics and Monte Carlo simulations. On regular lattices, defectors are overall extincted since cooperators, especially selfish cooperators, have great evolutionary advantages due to strong network reciprocity, and at the same time the number of altruistic cooperators decays. Conversely, abundant shortcuts in regular random networks lead to the prevalence of altruistic cooperators, but cooperators suffer from free-riding behaviors of defectors. Of particular interest, we find that small-world topology can simultaneously help cooperators successfully outperform defectors by means of strong network reciprocity, and enable rich contacting opportunities with defectors to facilitate the expansion of altruistic cooperators. Therefore, we clarify that small world is the optimal topology subject to the dominance of altruistic cooperators.91A22 (Primary) 34A34, 91B02 (Secondary) Copyright © 2017, The Authors. All rights reserved.

关键词： Monte Carlo methods

S265: RADIOMICS AND ARTIFICIAL INTELLIGENCE FOR IDENTIFICATION AND MONITORING OF SILENT CEREBRAL INFARCTS IN SICKLE CELL DISEASE: FIRST ANALYSIS FROM THE GENOMED4ALL EUROPEAN PROJECT

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HemaSphere 2022年第S3期6卷

作者： M. P. Boaro R. Biondi N. Biondini A. Collado Gimbert E. F. JM V. Pinto N. Romano V. Voi G. B. Ferrero M. Casale M. Cirillo G. Palazzi F. Cavalleri G. L. Forni G. Reggiani S. Perrotta M. Manu Pereira S. Zazo K. Marias M. De Montalembert P. Bartolucci E. van Beers F. Alvarez F. Cremonesi T. Sanavia P. Fariselli G. Castellani R. Manara R. Colombatti Woman's and Child's Health University of Padova Padova Italy Of Experimental Diagnostic and Specialty Medicine University of Bologna Bologna Italy Servei d'Oncologia i Hematologia Pediàtriques Hospital Universitari Vall d'Hebron Barcelona Spain Radiology Hospital Universitari Vall d'Hebron Barcelona Spain Centro della Microcitemia Anemie Congenite e Dismetabolismo del Ferro Ospedali Galliera Genova Italy Department of Diagnostic and Interventional Neuroradiology Ospedali Galliera Genova Italy Dipartimento di Scienze Cliniche e Biologiche Università di Torino Ospedale San Luigi Gonzaga Orbassano Italy Dipartimento di Scienze Cliniche e Biologiche University of Torino Torino Italy Donna del Bambino e di Chirurgia Generale e Specialistica Università̀ degli Studi della Campania “Luigi Vanvitelli” Napoli Italy Department of Advanced Medical and Surgical Sciences University of Campania “Luigi Vanvitelli Napoli Italy Dipartimento Integrato Materno Infantile Azienda Ospedale-Università di Modena e Reggio Emilia Modena Italy Neurological Department University of Modena Modena Italy Dipartimento della Donna del Bambino e di Chirurgia Generale e Specialistica Università̀ degli Studi della Campania “Luigi Vanvitelli” Napoli Italy Vall d'Hebron Research Institute Barcelona Spain Information Processing and Telecommunications Center Universidad Politécnica de Madrid Madrin Spain Computational Medicine Laboratory Institute of Computer Science FORTH Heraklion Greece Department of Pediatrics Hopital Necker Paris France Red Cell Genetic Disease Unit Université Paris Est Institut Mondor de Recherche Biomédicale (IMRB) Creteil France Universitair Medisch Centrum Utrecht Utrecht Netherlands Universidad Politecnica Madrid Madrid Spain Datawizard s.r.l Roma Italy Medical Sciences Division of Gastroenterology and Hepatology Città della Salute e della Scienza di Torino University of Turin Torino Italy Department of Physics University of Bologna Bologna Italy Neurosc

CTMC Investigation of Capture and Ionization Processes in P+H(1s) Collisions in Strong Transverse Magnetic Fields

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Communications in Theoretical physics 2015年第4期63卷 499-504页

作者：何斌王建国 R.K.Janev Data Center for High Energy Density Physics Research Institute of Applied Physics and Computational Mathematics Macedonian Academy of Sciences and Arts

The collision processes of proton with H(1s) atoms, which is embedded in strong transverse magnetic fields perpendicular to the initial velocity of the projectile, are studied with the classical trajectory Monte Carlo method in the energy range 25 keV /u–2000 keV /u and B ～ 104 T. It is found that the charge exchange cross section is decreased while the ionization cross section is increased significantly. The physics of magnetic field effects is analyzed by the time evolution of electron energy and trajectories, and it is found that these effects are induced by the diamagnetic term in the interaction, continuum electron trapping in the target regions and the Lorentz force. The velocity distributions of the ionized electrons, significantly influenced by the applied fields, are also presented.

关键词： classical tra jectory Monte Carlo transverse magnetic fields capture collision

DE CVn: An eclipsing post-common envelope binary with a circumbinary disk and a giant planet

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arXiv 2018年

作者： Han, Z.-T. Qian, S.-B. Zhu, L.-Y. Zhi, Q.-J. Dong, A.-J. Soonthornthum, B. Poshyachinda, S. Sarotsakulchai, T. Fang, X.-H. Wang, Q.-S. Voloshina, Irina P. O. Box 110 Kunming650216 China Guizhou Provincial Key Laboratory of Radio Data Processing School of Physics and Electronic Sciences Guizhou Normal University Guiyang550001 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences P. O. Box 110 Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China University of Chinese Academy of Sciences Yuquan Road 19# Sijingshang Block Beijing100049 China National Astronomical Research Institute of Thailand Ministry of Science and Technology Bangkok Thailand Sternberg Astronomical Institute Moscow State University Universitetskij prospect 13 Moscow119992 Russia

We present a timing analysis of the eclipsing post-common envelope binary (PCEB) DE CVn. Based on new CCD photometric observations and the published data, we found that the orbital period in DE CVn has a cyclic period oscillation with an amplitude of 28.08 s and a period of 11.22 years plus a rapid period decrease at a rate of P = -3.35 × 10-11ss-1. According to the evolutionary theory, secular period decreases in PCEBs arise from angular momentum losses (AMLs) driven by gravitational radiation (GR) and magnetic braking (MB). However, the observed orbital decay is too fast to be produced by AMLs via GR and MB, indicating that there could be other AML mechanism. We suggest that a circumbinary disk around DE CVn may be responsible for the additional AML. The disk mass was derived as a few × 10-4-10-3Mo, which is in agreement with that inferred from previous studies in the order of magnitude. The cyclic change is most likely result of the gravitational perturbation by a circumbinary object due to the Applegate's mechanism fails to explain such a large period oscillation. The mass of the potential third body is calculated as M3sin i′ = 0.011(±0.003)Mo. Supposing the circumbinary companion and the eclipsing binary is coplanar, its mass would correspond to a giant planet. This hypothetical giant planet is moving in a circular orbit of radius ∼ 5.75(±2.02) AU around its host star. Copyright © 2018, The Authors. All rights reserved.

关键词： Gravitation

Euclid Quick data Release (Q1) Combined Euclid and Spitzer galaxy density catalogues at z>1.3 and detection of significant Euclid passive galaxy overdensities in Spitzer overdense regions

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arXiv 2025年

作者： Mai, N. Mei, S. Cleland, C. Chary, R. Bartlett, J.G. Castignani, G. Dannerbauer, H. De Lucia, G. Fontanot, F. Scott, D. Andreon, S. Bhargava, S. Dole, H. Dussere, T. Stanford, S.A. Tran, V.P. Weaver, J.R. Duc, P.-A. Risso, I. Aghanim, N. Altieri, B. Amara, A. Auricchio, N. Aussel, H. Baccigalupi, C. Baldi, M. Balestra, A. Bardelli, S. Battaglia, P. Biviano, A. Bonchi, A. Bonino, D. Branchini, E. Brescia, M. Brinchmann, J. Caillat, A. Camera, S. Cañas-Herrera, G. Capobianco, V. Carbone, C. Carretero, J. Casas, S. Castellano, M. Cavuoti, S. Chambers, K.C. Cimatti, A. Colodro-Conde, C. Congedo, G. Conselice, C.J. Conversi, L. Copin, Y. Courbin, F. Courtois, H.M. Da Silva, A. Degaudenzi, H. Di Giorgio, A.M. Douspis, M. Dubath, F. Duncan, C.A.J. Dupac, X. Dusini, S. Ealet, A. Escoffier, S. Farina, M. Farinelli, R. Faustini, F. Ferriol, S. Finelli, F. Fosalba, P. Fotopoulou, S. Frailis, M. Franceschi, E. Fumana, M. Galeotta, S. George, K. Gillis, B. Giocoli, C. Gracia-Carpio, J. Granett, B.R. Grazian, A. Grupp, F. Haugan, S.V.H. Holmes, W. Hormuth, F. Hornstrup, A. Hudelot, P. Jahnke, K. Jhabvala, M. Keihänen, E. Kermiche, S. Kiessling, A. Kubik, B. Kümmel, M. Kunz, M. Kurki-Suonio, H. Le Boulc’h, Q. Le Brun, A.M.C. Le Mignant, D. Ligori, S. Lilje, P.B. Lindholm, V. Lloro, I. Mainetti, G. Maino, D. Maiorano, E. Mansutti, O. Marggraf, O. Martinelli, M. Martinet, N. Marulli, F. Massey, R. Maurogordato, S. Medinaceli, E. Mellier, Y. Meneghetti, M. Merlin, E. Meylan, G. Mora, A. Moresco, M. Moscardini, L. Nakajima, R. Neissner, C. Niemi, S.-M. Nightingale, J.W. Padilla, C. Paltani, S. Pasian, F. Pedersen, K. Percival, W.J. Pettorino, V. Pires, S. Polenta, G. Poncet, M. Popa, L.A. Pozzetti, L. Raison, F. Renzi, A. Rhodes, J. Riccio, G. Romelli, E. Roncarelli, M. Saglia, R. Sakr, Z. Sapone, D. Sartoris, B. Schewtschenko, J.A. Schneider, P. Scodeggio, M. Secroun, A. Seidel, G. Seiffert, M. Serrano, S. Université Paris Cité CNRS Astroparticule et Cosmologie Paris75013 France CNRS-UCB International Research Laboratory Centre Pierre Binetruy IRL2007 CPB-IN2P3 Berkeley United States Infrared Processing and Analysis Center California Institute of Technology PasadenaCA91125 United States University of California Los AngelesCA90095-1562 United States INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna Via Piero Gobetti 93/3 Bologna40129 Italy Tenerife La Laguna38200 Spain INAF-Osservatorio Astronomico di Trieste Via G. B. Tiepolo 11 Trieste34143 Italy IFPU Institute for Fundamental Physics of the Universe via Beirut 2 Trieste34151 Italy Department of Physics and Astronomy University of British Columbia VancouverBCV6T 1Z1 Canada INAF-Osservatorio Astronomico di Brera Via Brera 28 Milano20122 Italy Université Côte d’Azur Observatoire de la Côte d’Azur CNRS Laboratoire Lagrange Bd de l’Observatoire CS 34229 Nice06304 cedex 4 France Université Paris-Saclay CNRS Institut d’astrophysique spatiale Orsay91405 France Department of Physics and Astronomy University of California DavisCA95616 United States Department of Astronomy University of Massachusetts AmherstMA01003 United States Université de Strasbourg CNRS Observatoire astronomique de Strasbourg UMR 7550 Strasbourg67000 France INFN-Sezione di Genova Via Dodecaneso 33 Genova16146 Italy ESAC/ESA Camino Bajo del Castillo s/n. Urb. Villafranca del Castillo Madrid Villanueva de la Cañada28692 Spain School of Mathematics and Physics University of Surrey Guild-ford SurreyGU2 7XH United Kingdom Université Paris-Saclay Université Paris Cité CEA CNRS AIM Gif-sur-Yvette91191 France INFN Sezione di Trieste Via Valerio 2 TS Trieste34127 Italy SISSA International School for Advanced Studies Via Bonomea 265 TS Trieste34136 Italy Dipartimento di Fisica e Astronomia Università di Bologna Via Gobetti 93/2 Bologna40129 Italy INFN-Sezione di Bologna Viale Berti

The Euclid spacecraft will detect tens of thousands of clusters and protoclusters at z > 1.3 over the course of its mission. With a total coverage of 63.1 deg2, the Euclid Quick data Release 1 (Q1) is large enough to detect tens of clusters and hundreds of protoclusters at these early epochs. The Q1 photometric redshift catalogue enables us to detect clusters out to z 1.5;however, infrared imaging from the Spitzer Space Telescope extends this limit to higher redshifts by using high local projected densities of Spitzer-selected galaxies as signposts for cluster and protocluster candidates. We use Spitzer imaging of the Euclid Deep Fields (EDFs) to derive densities for a sample of Spitzer-selected galaxies at redshifts z > 1.3, building Spitzer IRAC1 and IRAC2 photometric catalogues that are 95% complete at a magnitude limit of IRAC2 =22.2, 22.6, and 22.8 for the Euclid Deep Field South, Euclid Deep Field Fornax, and Euclid Deep Field North, respectively. We apply two complementary methods to calculate galaxy densities: (1) aperture and surface density;and (2) the Nth-nearest-neighbour method. When considering a sample selected at a magnitude limit of IRAC2 1.3, and our catalogues will allow us to extend cluster and protocluster detections to z > 1.3 in the EDFs. © 2025, CC BY.

关键词： Active Galactic Nuclei

Optimal Estimation of Sensor Biases for Asynchronous Multi-Sensor data Fusion

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arXiv 2017年

作者： Pu, Wenqiang Liu, Ya-Feng Yan, Junkun Liu, Hongwei Luo, Zhi-Quan National Laboratory of Radar Signal Processing Collaborative Innovation Center of Information Sensing and Understanding Xidian University Xi'an710071 China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China Shenzhen Research Institute of Big Data Chinese University of Hong Kong Shenzhen518100 China

An important step in a multi-sensor surveillance system is to estimate sensor biases from their noisy asynchronous measurements. This estimation problem is computationally challenging due to the highly nonlinear transformation between the global and local coordinate systems as well as the measurement asynchrony from different sensors. In this paper, we propose a novel nonlinear least squares (LS) formulation for the problem by assuming the existence of a reference target moving with an (unknown) constant velocity. We also propose an efficient block coordinate decent (BCD) optimization algorithm, with a judicious initialization, to solve the problem. The proposed BCD algorithm alternately updates the range and azimuth bias estimates by solving linear least squares problems and semidefinite programs (SDPs). In the absence of measurement noise, the proposed algorithm is guaranteed to find the global solution of the problem and the true biases. Simulation results show that the proposed algorithm significantly outperforms the existing approaches in terms of the root mean square error (RMSE). Copyright © 2017, The Authors. All rights reserved.

关键词： Mean square error