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Journal of Landscape Research 2020年第3期12卷 33-38,46页

作者： YANG Xin HE Shuang ZHANG Qi School of Architecture and Art North China University of TechnologyBeijing 100043China View Unlimited Landscape Architecture Studio of China Urban Construction Deisgn&Research Institute Co. LtdBeijing 100120China

As an important public space in the city,street space is the second residence of *** Yangmeizhu Street as the research object,this study established a street microclimate model in Beijing through microclimate measurement and simulation,and then calculated thermal comfort index of the street and evaluated thermal comfort of the street space and distribution *** evaluation method used grid method to decompose and study and made several 10m×10m grids for inner space of the street,so as to compare deeply difference of microclimate environment in the street and analyze quantitatively relevance between street space elements(street pavement,street greening,building shadow coverage)and thermal comfort(physiological equivalent temperature PET)in the ***,adaptive strategy of microclimate on street level was put forward to improve the environmental quality of public space in the old city by means of landscape design,aiming at creating a resilient and humanized street space and improving adaptability of microclimate and thermal comfort for living.

关键词： Thermal comfort grid method Street space Yangmeizhu Street Microclimate environment

Wave propagation across fluid-solid interfaces:a grid method approach

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Wave propagation across fluid-solid interfaces:a grid method...

中国科学院地质与地球物理研究所2004学术年会

作者： Jianfeng Zhang Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China.

This paper presents a new numerical technique for modelling wave propagation in media with both fluid(acoustic) and solid(elastic) regions,as found for instance in a marine seismic case. The scheme can correctly satisfy the fluid-solid interface conditions and accurately models the arbitrary interface *** work is an extension of the grid method,which is able to model wave propagation in heterogeneous solid(elastic) media with arbitrary surface topography and irregular *** scheme is developed by formulating the problem in terms of displacements in elastic regions and pressure in acoustic regions with an explicit boundary between *** fluid-solid interface conditions on this explicit boundary are implemented by introducing an integral approach to the fluid-solid interface *** solution in terms of pressure in acoustic regions together with this integral approach means that no extra computational cost is needed to implement the fluid-solid interface conditions for a complex geometry,instead of resulting in additional computations as with the spectralelement, finite-element or finite-difference *** this paper an acoustic grid method is developed to solve the acoustic problem inside the fluid,and the(elastic) grid method,which is improved based on a parsimonious staggered-grid scheme,is used to solve the elastic problem inside the *** numerical dispersion and stability criteria for the acoustic grid method are discussed in *** with an analytical solution demonstrates that the proposed scheme handles the fluid-solid interface conditions *** of wave propagation in a mixed fluid/solid model with both weak and strong sinusoidal fluid-solid interfaces illustrate the suitability of the proposed scheme for modelling wave propagation across fluid-solid interfaces with complex geometries.

关键词： finite difference grid method marine seismic modelling sea bottom topography

MICRO-EXPERIMENTAL STUDY OF LARGE PLASTIC DEFORMATION FOR HIGH-PURITY POLYCRYSTALLINE ALUMINUM

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Acta Mechanica Sinica 1991年第4期7卷 360-368页

作者：仲政杨卫黄克智 Currently in the Department of Engineering Mechanics Tongji University. Tsinghua University Beijing 100084China

This paper aims at revealing various micro- deformation characteristics, such as crystalline slip and grain boundary slide, which are recorded under scanning electronic microscope for high-purity aluminum tensile specimen at room temperature. These experimental data provide us direct evidence for shear localization near the grain boundary network via multi- directional grain boundary slide. The nonuniform deformation induced in the grain interiors would have decisive effect on the plastic flow and failure of polycrystalline materials.

关键词： polycrystals large plastic deformation grain boundary sliding micromechanics grid method

NUMERICAL SIMULATION OF ELASTIC WAVE PROPAGATION IN ANISOTROPIC MEDIA

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Acta Mechanica Solida Sinica 2000年第1期13卷 50-59页

作者： Zhang, JF Liu, TL Dalian Univ Technol State Key Lab Struct Anal Ind Equipment Dalian 116024 Peoples R China

A new numerical simulation algorithm is presented for the elastic wave propagation in heterogeneous anisotropic media. We make discretization of the computational domain by using triangular and quadrangular grids. The scheme is based on integral equilibrium at each node to simulate the elastic wave propagation in heterogeneous anisotropic media. The scheme is very flexible in dealing with arbitrary surface topography, inner openings, liquid-solid boundaries and irregular interfaces. Moreover, tho free-surface condition of complex geometrical boundaries can be satisfied naturally. This work is an extension of the grid method for the elastic wave propagation in heterogeneous isotropic media, and a quadrangular grid with low computational cost is also introduced.

关键词： numerical modeling anisotropy finite difference grid method

Classified denoising method for laser point cloud data of stored grain bulk surface based on discrete wavelet threshold

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International Journal of Agricultural and Biological Engineering 2016年第4期9卷 123-131页

作者： Shao Qing Xu Tao Yoshino Tatsuo Song Nan Zhu Hang School of Mechanical Science and Engineering Jilin UniversityChangchun 130022China

Surfaces of stored grain bulk are often reconstructed from organized point sets with noise by 3-D laser scanner in an online measuring *** a result,denoising is an essential procedure in processing point cloud data for more accurate surface reconstruction and grain volume calculation.A classified denoising method was presented in this research for noise removal from point cloud data of the grain bulk *** on the distribution characteristics of cloud point data,the noisy points were divided into three types:The first and second types of the noisy points were either sparse points or small point cloud data deviating and suspending from the main point cloud data,which could be deleted directly by a grid method;the third type of the noisy points was mixed with the main body of point cloud data,which were most difficult to *** point cloud data with those noisy points were projected into a horizontal *** image denoising method,discrete wavelet threshold(DWT)method,was applied to delete the third type of the noisy *** kinds of denoising methods including average filtering method,median filtering method and DWT method were applied respectively and compared for denoising the point cloud *** results show that the proposed method remains the most of the details and obtains the lowest average value of RMSE(Root Mean Square Error,0.219)as well as the lowest relative error of grain volume(0.086%)compared with the other two ***,the proposed denoising method could not only achieve the aim of removing noisy points,but also improve self-adaptive ability according to the characteristics of point cloud data of grain bulk *** results from this research also indicate that the proposed method is effective for denoising noisy points and provides more accurate data for calculating grain volume.

关键词： point cloud data denoising grid method discrete wavelet threshold(DWT)method 3-D laser scanning stored grain

Robot Global Path Planning Based on an Improved Ant Colony Algorithm

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Journal of Computer and Communications 2016年第2期4卷 11-19页

作者： Jingang Cao Department of Computer North China Electric Power University Baoding China

Aiming at the disadvantages of the basic ant colony algorithm, this paper proposes an improved ant colony algorithm for robot global path planning. First, adjust the pheromone evaporation rate dynamically to enhance the global search ability and convergence speed, and then modify the heuristic function to improve the state transition probabilities in order to find the optimal solution as quickly as possible;and finally change the pheromone update strategy to avoid premature by strengthening pheromone on the optimal path and limiting pheromone level. Simulation results verify the effectiveness of the improved algorithm.

关键词： Path Planning Ant Colony Algorithm grid method

Research on optimization of valve open time of the launch barge's ballast tanks

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Journal of Marine Science and Application 2009年第1期8卷 1-6页

作者：孙承猛纪卓尚大连理工大学船舶CAD工程中心辽宁大连116024

Launch barge is an effective tool for transporting ship segments from one place to another in shipyards. During shifting of segments onto a barge, the slideway on the barge＇s deck must be adjusted to maintain the same level as the wharf and also the barge must be kept level by adjusting the water in the ballast tanks. When to open the adjusting valves is an important factor influencing the barge＇s trim during the water-adjustment process. Because these adjustments are complex a mathematical model was formulated,after analyzing the characteristics of the process of moving the segments onto the barges deck, and considering the effects of this movement＇s speed and variations in tidal levels during the move. Then the model was solved by the penalty function method, the grid method, and improved simulated annealing, respectively. The best optimization model and its corresponding solution were then determined. Finally, it was proven that the model and the method adopted are correct and suitable, by calculating and analysing an example.

关键词： launch barge stowage penalty function method simulated annealing method grid method

Global Path Planning of Unmanned Surface Vehicles Based on Deep Q Network

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Global Path Planning of Unmanned Surface Vehicles Based on D...

第43届中国控制会议

作者： Shuhao Li Yuehui Ji Junjie Liu Zhongli Bai Jiajun Hu Qiang Gao Tianjin Key Laboratory of Control Theory and Application for Complex Systems Maritime College Tianjin University of Technology

The paper proposes an autonomous global path planning algorithm for unmanned surface vehicles(USV) in complex sea areas based on Deep Q Network(DQN).This algorithm integrates the artificial potential field method with the DQN algorithm to design action space and a new greedy *** also introduces a reward function based on potential energy and a penalty item for threat *** results demonstrate that compared to the traditional DQN algorithm,the algorithm proposed in this paper reduces training time by 35.27%,shortens path length by 8.71%,and decreases convergence iterations by 56.36%.Compared to the other three algorithms,such as Q-learning,the paths planned by the algorithm in this paper are more reasonable,smooth,and *** research results validate the practicality and effectiveness of the proposed algorithm,which has significant practical implications for the development of autonomous global path planning technology for USV.

关键词： Path planning Unmanned surface vehicles Deep Q network Artificial potential field grid method

The method Based On Dijkstra Of Multi-directional Ship’s Path Planning

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The Method Based On Dijkstra Of Multi-directional Ship’s Pa...

第32届中国控制与决策会议

作者： Zihui Cheng Huajun Zhang Qin Zhao Automated Institute Wuhan University of Technology

Aiming at the problem of the shortest path’s optimization for direct navigation of ships,the Dijkstra algorithm search is *** environment of the ship’s navigation area was modeled by rasterization and *** the four-direction search,eight-direction search and arbitrary-angle search based on the Dijkstra algorithm were improved,and the three search methods were *** experiments and research results show that the improved arbitrary angle search method can best meet the requirement of the shortest direct flight path.

关键词： Path optimization grid method Puffing process Dijkstra algorithm

Research on AUV path planning based on improved Genetic Algorithm

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Research on AUV path planning based on improved Genetic Algo...

第35届中国过程控制会议

作者： Yijun Qi Xiaoming Huang University of Bristol Bristol BS81QU United Kingdom Dalian University of Technology School of Chemical Engineering Ocean and Life Science Dalian University of Technology

This study explores an enhanced genetic algorithm for 3D path planning in Autonomous Underwater Vehicles(AUVs). It builds on classical genetic algorithms, adding safety and smoothness criteria to the path length and using a multi-objective search method. Simulations on engineering charts show that this improved algorithm achieves better convergence and global search performance than traditional models, enhancing practical applications in underwater navigation.

关键词： Genetic algorithm AUV Path planning grid method Multi-objective