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Modeling multilook polarimetric SAR images with heavy-tailed rayleigh distribution and novel estimation based on matrix log-cumulants

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Science China(Information Sciences) 2013年第6期56卷 60-73页

作者： LIU tao CUI HaoGui mao tao XI ZeMin GAO Jun Electronic School of Engineering Naval University of Engineering Fourth Department Headquarters of Navy

With the improvements in modern radar resolution,the Gaussian-fluctuation model based on the central limit theorem does not accurately describe the scattering echo from *** contrast,the heavytailed Rayleigh distribution,based on the generalized central limit theorem,performs well in modeling the synthetic aperture radar(SAR) images,whereas its application to multi-look image processing is *** describe successful modeling of multilook polarimetric SAR images with the heavy-tailed Rayleigh distribution and present novel parameter estimators based on matrix log-cumulants for the heavy-tailed Rayleigh distribution including the equivalent number of looks(ENL).First,a compound variable of heavy-tailed Rayleigh distribution is divided into a product of a positive alpha-stable variable and a complex Gaussian *** parameter estimations of the characteristic exponent and scale parameter based on log-cumulants in a single polarization channel are then ***,the matrix log-cumulants(MLCs) for full polarization in multilook images are obtained,which can be applied to estimate model ***,a novel ENL estimator based on MLC is presented that describes the model more *** to all other multivariable product models,this estimator performs better than existing ***,calculations on both simulated and real data are performed that give good fits with theoretical *** processing in one image with a fixed pixel number can improve parameter estimations over single-look *** heavy-tailed Rayleigh model with its parameter estimation provides a new method to analyze the multilook polarimetric SAR images for target detection and classification.

关键词： heavy-tailed Rayleigh distribution multilook polarimetric synthetic aperture radar mellin transform matrix log-cumulants

SUPPLEMENT AND IMPROVEMENT OF HOLLY-PREISSMANN SCHEME

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Journal of Hydrodynamics 2004年第4期16卷 468-473页

作者： XIEZuo-tao ZHANGXiao-feng TANGuang-ming StateKeyLaboratoryofWaterResourcesandHydropowerEngineeringScience WuhanUniversity430072China

Using the undetermined coefficient method, Holly-Preissmann scheme isimproved effectively. The scheme with the minus velocity is added, and a new conservative scheme isalso presented on the basis of original scheme. T... 详细信息

关键词： holly-preissmann scheme conservative convection equation numerical scheme undetermined coefficient method

Multicolor Optical Monitoring of the γ-Ray Emitting Narrow-line Seyfert 1 Galaxy PMN J0948+0022 from 2020 to 2021

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Research in Astronomy and Astrophysics 2022年第7期22卷 60-72页

作者： Yu-Xin Xin Ding-Rong Xiong Jin-ming Bai Hong-tao Liu Kai-Xing Lu Ji-Rong mao Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China

In order to study the physical properties of the γ-ray emitting narrow-line Seyfert 1(NLS1) galaxy population,photometric and spectral observations of the γ-ray emitting NLS1 PMN J0948+0022 were made with the Lijiang2.4 m optical telescope of Yunnan Observatories,Chinese Academy of *** data in the B and R bands were collected for 50 nights from 2020 January to 2021 *** the observation epoch,the variability amplitudes are 73.67% in the B band and 79.96% in the R ***-day variability is found in two observation nights,and the duty cycle value is 29% with variability amplitude> 12.9% in the R band,which support the presence of the relativistic jets in the *** redder-when-brighter(RWB) chromatic trend(or steeper-when-brighter trend) appears on intra-day and long *** RWB trend is dominated by the radiation of accretion disk and jet,and resembles those in flat spectrum radio *** PMN J0948+0022 is brighter than 17.5 in the R band,there is no color change *** analyzing the spectral data of PMN J0948+0022,we obtained the black hole mass of M.=1.61×10^(7) Mand accretion rate of M=93,and confirmed that PMN J0948+0022 is a super-Eddington accreting *** redshifts of reverberation mapped super-Eddington accreting active galactic nuclei can be expanded by PMN J0948+0022 up to above ***-Eddington accreting NLS1 galaxies were chosen as a new type of cosmological candle in the *** J0948+0022 may be used as a target for the next step of reverberation mapping monitoring project of super-Eddington accreting massive black holes.

关键词： galaxies:jets galaxies:photometry galaxies:Seyfert galaxies:active

AN ASYMPTOTIC SOLUTION OF VELOCITY FIELD IN SHIP WAVES

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Journal of Hydrodynamics 2006年第4期18卷 387-392页

作者： WU Yun-gang tao ming-de Department of Mechanics and Engineering Science and The Key Laboratory of Wave Scattering and RemoteSensing Information Fudan University Shanghai 200433 China

The stationary phase method in conventional Lighthill＇s two-stage scheme to get the expressions of the velocity field was given up in this paper. The method that Ursell had used in deducing the elevation expression of ship wave was adopted, and an asymptotic solution of velocity field of ship waves on an inviscid fluid that is perfectly fit for the region inside and outside the critical lines was obtained. It is very convenient to be used in SAR technique.

关键词： ship waves velocity field remote sensing,asymptotic solution

A Heuristic Approach for Context-Aware Recommendation Using Rough Set Theory

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Chinese Journal of Electronics 2018年第3期27卷 500-506页

作者： HE ming DONG tao LIU Yi College of Computer Science Beijing University of Technology

Context-aware recommender systems, aiming to further improve performance accuracy and user satisfaction by fully utilizing contextual information, have recently become one of the hottest topics in the domain of recommender systems. However, not all contextual information might be relevant or useful for recommendation purposes, and little work has been done on measuring how important the contextual information for *** propose a heuristic optimization algorithm based on rough set theory and collaborative filtering to using contextual information more efficiently for boosting recommendation. Our approach involves three processes. First, significant attributes to represent contextual information are extracted and measured to identify recommended items using rough set theory. Second, the user similarity is evaluated in a target context consideration. Third, collaborative filtering is applied to recommend appropriate *** perform an empirical comparison of three approaches on two real-world data sets. The experimental results show that the proposed approach generates more accurate predictions.

关键词： Recommendation Context Context-aware recommendation Collaborative filtering Rough set

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水稻软盘毯状苗分离机设计与试验

农机化研究 2025年第2期47卷 86-90页

作者：赵语轩毛欣衣淑娟陶桂香田永久黑龙江八一农垦大学程学院黑龙江大庆163319 黑龙江省水稻生态育秧装置及全程机械化工程技术研究中心黑龙江大庆163319

目前,水稻种植环节中育秧环节与移栽环节之间的水稻苗盘分离环节的机械化程度相较于其他环节较为薄弱。为提高水稻全程机械化作业水平,降低生产成本,设计了一种适用于水稻毯状苗与塑料软盘分离的机械装置,主要由输送机构、分离机构、扶... 详细信息

目前,水稻种植环节中育秧环节与移栽环节之间的水稻苗盘分离环节的机械化程度相较于其他环节较为薄弱。为提高水稻全程机械化作业水平,降低生产成本,设计了一种适用于水稻毯状苗与塑料软盘分离的机械装置,主要由输送机构、分离机构、扶苗机构、集苗机构、动力系统和机架组成。对装置的结构及工作原理进行了描述,分析确定各个机构的结构参数。以分离率、茎叶损伤率、基质损伤率为试验指标进行苗盘分离试验,结果表明:水稻软盘毯状苗分离机作业效果较好,分离成功率在95%以上,能够降低生产成本,提高生产效率;茎叶损伤率及基质损伤率均在3%以下,保证后续水稻毯状苗移栽工作的顺利进行,较小的茎叶损伤与基质损伤也保证了后续水稻生长过程中不会受到较大的影响,满足水稻育秧农艺要求和水稻工厂化技术规范要求。

关键词：水稻毯状苗分离机机械化生产

Draft genome of an Aerophobetes bacterium reveals a facultative lifestyle in deep-sea anaerobic sediments

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Science Bulletin 2016年第15期61卷 1176-1186页

作者： Yong Wang Zhao-ming Gao Jiang-tao Li Salim Bougouffa Ren mao Tian Vladimir B. Bajic Pei-Yuan Qian Sanya Institute of Deep Sea Science and Engineering ChineseAcademy of Sciences Sanya 572000 China Division of Life Science Hong Kong University of Science and Technology Clear Water Bay Hong Kong China State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092 China Computational Bioscience Research Center King Abdullah University of Science and Technology Thuwal Jeddah 23955-6900 Saudi Arabia

Aerophobetes （or CD12） is a recently defined bacterial phylum, of which the metabolic processes and ecological importance remain unclear. In the present study, we obtained the draft genome of an Aerophobetes bac- terium TCSI from saline sediment near the Thuwal cold seep in the Red Sea using a genome binning method. Analysis of 16S rRNA genes of TCS1 and close relatives revealed wide distribution of Aerophobetes in deep-sea sediments. Phylogenetic relationships showed affinity between Aerophobetes TCS 1 and some thermophilic bac- terial phyla. The genome of TCS1 （at least 1.27 Mbp） contains a full set of genes encoding core metabolic path- ways, including glycolysis and pyruvate fermentation to produce acetyl-CoA and acetate. The identification of cross-membrane sugar transporter genes further indicates its potential ability to consume carbohydrates preserved inthe sediment under the microbial mat. Aerophobetes bac- terium TCS1 therefore probably carried out saccharolytic and fermentative metabolism. The genes responsible for autotrophic synthesis of acetyl-CoA via the Wood-Ljung- dahl pathway were also found in the genome. Phylogenetic study of the essential genes for the Wood-Ljungdahl pathway implied relative independence of Aerophobetes bacterium from the known acetogens and methanogens. Compared with genomes of acetogenic bacteria, Aero- phobetes bacterium TCS 1 genome lacks the genes involved in nitrogen metabolism, sulfur metabolism, signal trans- duction and cell motility. The metabolic activities of TCS 1 might depend on geochemical conditions such as supplies of CO2, hydrogen and sugars, and therefore the TCSI might be a facultative bacterium in anaerobic saline sedi- ments near cold seeps.

关键词： Deep-sea sediment Aerophobetes Metagenome Sugar fermentation Cold seep

Speech emotion recognition with unsupervised feature learning

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Frontiers of Information Technology & Electronic Engineering 2015年第5期16卷 358-366页

作者： Zheng-wei HUANG Wen-tao XUE Qi-rong mao Department of Computer Science and Communication Engineering Jiangsu University

Emotion-based features are critical for achieving high performance in a speech emotion recognition(SER) system. In general, it is difficult to develop these features due to the ambiguity of the ground-truth. In this paper, we apply several unsupervised feature learning algorithms(including K-means clustering, the sparse auto-encoder, and sparse restricted Boltzmann machines), which have promise for learning task-related features by using unlabeled data, to speech emotion recognition. We then evaluate the performance of the proposed approach and present a detailed analysis of the effect of two important factors in the model setup, the content window size and the number of hidden layer nodes. Experimental results show that larger content windows and more hidden nodes contribute to higher performance. We also show that the two-layer network cannot explicitly improve performance compared to a single-layer network.

关键词： Speech emotion recognition Unsupervised feature learning Neural network Affect computing

Quantum Dynamics of Li+HF/DF Reaction Investigated by a State-to-State Time-dependent Wave Packet Approach

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Chinese Journal of Chemical Physics 2015年第4期28卷 -页

作者： Wen-tao Li mao-du Chen Zhi-gang Sun School of Physics and Optoelectronic Technology Dalian University of Technology Dalian 116024ChinaState Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China School of Physics and Optoelectronic Technology Dalian University of Technology Dalian 116024China State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

Using the reactant coordinate based time-dependent wave packet method, on the APW potential energy surface, the differential and integral cross sections of the Li+DF/HF(v=0, j=0, 1) reactions were calculated over the collision energy range from the threshold to 0.25 eV. The initial state-specified reaction rate constants of the title reaction were also calculated. The results indicate that, compared with the Li+DF reaction, the product LiF of Li+HF reaction is a little more rotationally excited but essentially similar. The initial rotational excitation from j=0 to 1 has little effect on the Li+DF reaction. However, the rotational excitation of DF does result in a little more rotationally excited product LiF. The different cross section of both reactions is forward biased in the studied collision energy range, especially at relatively high collision energy. The resonances in the Li+HF reaction may be identifiable as the oscillations in the product ro-vibrational state-resolved integral cross sections and backward scattering as a function of collusion energy. For the Li+HF reaction, the rate constant is not sensitive to the temperature and almost has no change in the temperature range considered. For the Li+DF reaction, the rate constant increase by a factor of about 10 in the temperature range of 100–300 K. Brief comparison for the total reaction probabilities and integral cross section of the Li+HF reaction has been carried out between ours and the values reported previously. The agreement is good, and the difference should come from the better convergence of our present calculations.

关键词： Quantum wavepacket Integral and differential cross section Reaction rate constant Li+HF/DF Isotope effect