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Petroleum Science 2023年第1期20卷 199-211页

作者： wen-zhuo tan Bang-Yu Wu Rui Li Bo Li School of Mathematics and Statistics Xi'an Jiaotong UniversityXi'anShaanxi710049China School of Mathematics and Statistics Shaanxi Normal UniversityXi'anShaanxi710062China SNOPEC Key Laboratory of Geophysics NanjingJiangsu211103China

The large storage requirement is a critical issue in cross-correlation imaging-condition based reverse time migration(RTM),because it requires the operation of the source and receiver wavefields at the same *** boundary value method(BVM),based on the finite difference method(FDM),can be used to reconstruct the source wavefield in the reverse time propagation in the same way as the receiver wavefield,which can reduce the storage burden of the RTM *** that the FDM cannot well handle models with discontinuous material properties and rough interfaces,we develop a source wavefield reconstruction strategy based on the finite element method(FEM),using proper orthogonal decomposition(POD)to enhance computational *** this method,we divide the whole time period into several segments,and construct the POD basis functions to get a reduced order model(ROM)for the source wavefield reconstruction in each *** show the corresponding quantitative analysis of the storage requirement of the *** tests on the homogeneous model show the effectiveness of the proposed method,while the layered model and part of the Marmousi model tests indicate that the POD-FEM can keep an excellent balance between computational efficiency and memory usage compared with the full-stored method(FSM)and the BVM,and can be effectively applied in imaging.

关键词： Reverse time migration Seismic wavefield reconstruction Finite element modeling Proper orthogonal decomposition

Augmented Virtual Stiffness Rendering of a Cable-driven SEA for Human-Robot Interaction

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IEEE/CAA Journal of Automatica Sinica 2017年第4期4卷 714-723页

作者： Ningbo Yu Wulin Zou wen tan zhuo Yang IEEE Institute of Robotics and Automatic Information Systems Nankai University Tianjin Key Laboratory of Intelligent Robotics Nankai University Haihe Education Park

Human-robot interaction(HRI) is fundamental for human-centered robotics, and has been attracting intensive research for more than a decade. The series elastic actuator(SEA) provides inherent compliance, safety and further benefits for HRI, but the introduced elastic element also brings control difficulties. In this paper, we address the stiffness rendering problem for a cable-driven SEA system, to achieve either low stiffness for good transparency or high stiffness bigger than the physical spring constant, and to assess the rendering accuracy with quantified metrics. By taking a velocity-sourced model of the motor, a cascaded velocity-torque-impedance control structure is established. To achieve high fidelity torque control, the 2-DOF(degree of freedom) stabilizing control method together with a compensator has been used to handle the competing requirements on tracking performance, noise and disturbance rejection,and energy optimization in the cable-driven SEA system. The conventional passivity requirement for HRI usually leads to a conservative design of the impedance controller, and the rendered stiffness cannot go higher than the physical spring constant. By adding a phase-lead compensator into the impedance controller,the stiffness rendering capability was augmented with guaranteed relaxed passivity. Extensive simulations and experiments have been performed, and the virtual stiffness has been rendered in the extended range of 0.1 to 2.0 times of the physical spring constant with guaranteed relaxed passivity for physical humanrobot interaction below 5 Hz. Quantified metrics also verified good rendering accuracy.

关键词： Cable actuation impedance control physical human-robot interaction relaxed passivity series elastic actuator stabilizing 2-DOF(degree of freedom) controllers

Isotopic insights on quantitative assessments of interaction of eco-hydrological processes in multi-scale karst watersheds

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International Soil and Water Conservation Research 2024年第1期12卷 156-170页

作者： zhuo Hao Yang Gao Qingwen Zhang wen wen Agricultural Clean Watershed Research Group Institute of Environment and Sustainable Development in AgricultureCAASBeijing100081China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China School of Humanities and Social Sciences Beijing Institute of TechnologyBeijing100081China

The dynamics of hydrological processes and the storage mechanisms of karst water resources are the most important issues in karst *** impact of environmental changes on water quantity,and the evaluation and quantification of eco-hydrological processes remain poorly *** this study,high-frequency continuous monitoring in multi-scale karst watersheds in Southwest China combined the approaches of water isotopes and the hybrid single-particle lagrangian integrated trajectory(HYSPLIT)model to identify the recharge mechanisms between atmospheric vapor,rainfall,surface water,and groundwater,and to reveal the interaction of eco-hydrological *** dominant moisture sources in Puding(PD)County were the Indian Ocean(43-69%)and local moisture(24-33%).Theδ^(18)O and deuterium excess(d-excess)values showed a positive correlation indicating that secondary or sub-cloud evaporation was prominent in the wet *** water line-conditioned excess(lc-excess)indicated that karst water interacted with recent precipitation,groundwater,and evaporation across *** to its specific hydrogeological structure,surface water and rainwater have a higher contribution rate to groundwater *** Chenqi stream replenished the Houzhai River mainly in the form of groundwater,with percentages ranging from 38.1 to 93.5%in the wet season,and 47.8-80.1%in the dry *** the Houzhai outlet,surface water and groundwater interconverted frequently with a percentage of 45.6-49.1%.We believe this is the first systematic study to quantify the supply relationship between water vapor transport,rainfall,surface water and groundwater in the Chinese karst zone,making a significant move forward in the field of karst hydrological processes and improving the efficiency of water resource evaluation and management.

关键词： Stable isotope Moisture sources Water cycle Karst watersheds

Stochastic Variational Inference-Based Parallel and Online Supervised Topic Model for Large-Scale Text Processing

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Journal of Computer Science & Technology 2018年第5期33卷 1007-1022页

作者： Yang Li wen-zhuo Song Bo Yang College of Computer Science and Technology Jilin University Changchun 130012 China Key Laboratory of Symbolic Computation and Knowledge Engineering Ministry of Education Jilin University Changchun 130012 China Aviation University of Air Force Changchun 130062 China

Topic modeling is a mainstream and effective technology to deal with text data, with wide applications in text analysis, natural language, personalized recommendation, computer vision, etc. Among all the known topic models, supervised Latent Dirichlet Allocation （sLDA） is acknowledged as a popular and competitive supervised topic model. How- ever, the gradual increase of the scale of datasets makes sLDA more and more inefficient and time-consuming, and limits its applications in a very narrow range. To solve it, a parallel online sLDA, named PO-sLDA （Parallel and Online sLDA）, is proposed in this study. It uses the stochastic variational inference as the learning method to make the training procedure more rapid and efficient, and a parallel computing mechanism implemented via the MapReduce framework is proposed to promote the capacity of cloud computing and big data processing. The online training capacity supported by PO-sLDA expands the application scope of this approach, making it instrumental for real-life applications with high real-time demand. The validation using two datasets with different sizes shows that the proposed approach has the comparative accuracy as the sLDA and can efficiently accelerate the training procedure. Moreover, its good convergence and online training capacity make it lucrative for the large-scale text data analyzing and processing.

关键词： topic modeling, large-scale text classification, stochastic variational inference, cloud computing online learning

Study on Synthesis of Azo-Coupling Products of 3-Aminotropolone

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Chinese Chemical Letters 2001年第2期12卷 103-106页

作者： wen Tao GAO zhuo ZHENG Department of Chemistry Jinzhou Teachers CollegeJinzhou 121003 Dalian Institute of Chemical Physics Chinese Academy of ScienceDalian 116023

3-Acetamidotropolone 1 reacted with p-substitutedbenzenediazonium chloride in pyridine to afford 3-acetamido-5-(4-substitutedphenylazo)tropolones 2a~f. Hydrolysis of compounds 2a~f gave 3-amino-5-(4-substitutedphenylazo)tropolones 3a~f which could not be obtained directly from reactions of 3-aminotropolone with p-substitutedbenzenediazonium chloride. The structures of these new compounds 2a, 2c~f, 3a, 3c~f were confirmed from the elemental analysis and spectral data.

关键词： 3-Acetamidotropolone 3-aminotropolone synthesis azo-coupling electrophilic substitution

Robust key point descriptor for multi-spectral image matching

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Journal of Systems Engineering and Electronics 2014年第4期25卷 681-687页

作者： Yueming Qin Zhiguo Cao wen zhuo Zhenghong Yu National Key Laboratory of Science and Technology on Multi-spectral Information Processing School of AutomationHuazhong University of Science and Technology Yichang Testing Technique R&D Institute

Histogram of collinear gradient-enhanced coding （HCGEC）, a robust key point descriptor for multi-spectral image matching, is proposed. The HCGEC mainly encodes rough structures within an image and suppresses detailed textural information, which is desirable in multi-spectral image matching. Experiments on two multi-spectral data sets demonstrate that the proposed descriptor can yield significantly better results than some state-of- the-art descriptors.

关键词： collinear gradient-enhanced coding (CGEC) key pointdescriptor multi-spectral image matching.

Wronskian Form Solutions for a Variable Coefficient Kadomtsev-Petviashvili Equation

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Communications in Theoretical Physics 2014年第3期61卷 339-343页

作者： LU zhuo-Sheng REN wen-Xiu School of Science Beijing University of Posts and Telecommunications Beijing 100876 China School of Science Inner Mongolia University of Technology Hohhot 010051 China

Starting from a simple transformation, and with the aid of symbolic computation, we establish the relationship between the solution of a generalized variable coefficient Kadomtsev–Petviashvili(vKP) equation and the solution of a system of linear partial differential equations. According to this relation, we obtain Wronskian form solutions of the vKP equation, and further present N-soliton-like solutions for some degenerated forms of the vKP equation. Moreover,we also discuss the influences of arbitrary constants on the soliton and N-soliton solutions of the KPII equation.

关键词： variable coefficient KP equation wronsian form solution multi-soliton-like solution symboliccomputation

A Composite Risk Measure Framework for Decision Making Under Uncertainty

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Journal of the Operations Research Society of China 2019年第1期7卷 43-68页

作者： Peng-Yu Qian Zi-zhuo Wang Zai-wen wen Graduate School of Business Columbia UniversityNew YorkNY 10027USA Department of Industrial and Systems Engineering University of MinnesotaMinneapolisMN 55455USA Beijing International Center forMathematical Research PekingUniversityBeijing 100871China

In this paper,we present a unified framework for decision making under *** framework is based on the composite of two risk measures,where the inner risk measure accounts for the risk of decision if the exact distribution of uncertain model parameters were given,and the outer risk measure quantifies the risk that occurs when estimating the parameters of *** show that the model is tractable under mild *** framework is a generalization of several existing models,including stochastic programming,robust optimization,distributionally robust *** this framework,we study a few new models which imply probabilistic guarantees for solutions and yield less conservative results compared to traditional *** experiments are performed on portfolio selection problems to demonstrate the strength of our models.

关键词： Risk management Stochastic programming Portfolio management

SPATIAL DIFFERENTIATION OF LAND TRANSFER——Case Study of Shanghai, Nanjing and Taizhou in Changjiang River Delta

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Chinese Geographical Science 2006年第1期16卷 24-31页

作者： DU wen-xing HUANG Xian-jin ZHAI wen-xia PENG Bu-zhuo Department of Urban and Resources Sciences Nanjing University Nanjing 210093 P. R. China Department of Urban Plnnning and Resources Sciences Xianning College Xianning 437005 P. R. China

The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households＇ behavior. This paper selected I l factors covering four aspects of rural households＇ family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households＇ questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang （Yangtze） River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households＇ behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.

关键词： land transfer spatial differentiation land transaction Changjiang River Delta

Fragmentation Behavior and Ionization Potentials of Aluminum Clusters Al_n(n≤40)

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Chemical Research in Chinese Universities 2010年第2期26卷 294-299页

作者： ZHANG Wei LI zhuo ZHANG Gang LU wen-cai State Key Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University Changchun 130021 P R. China Laboratory of Fiber Materials and Modern Textile the Growing Base for State Key Laboratory College of Physics Qingdao University Qingdao 266071 P. R. China

Al2-Al40 clusters were studied by means of the all-electron DFT method. The properties of the aluminum clusters including binding energy, the second difference in energy, HOMO-LUMO gap, especially fragmentation energies and ionization potentials, were analyzed. The main products from the dissociations of aluminum cluster ions are shown to be Al ＋ Al^＋n-1 for the larger clusters, and Al^＋＋Aln-1 for the smaller ones. And, the calculated ionization potentials are consistent with the experiment data.

关键词： Al cluster Fragmentation behavior Ionization potential