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A lightweight semantic segmentation algorithm integrating CA and ECA-Net modules

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Optoelectronics Letters 2024年第9期20卷 568-576页

作者： guo Zhihao MA Dongmei LUO Xiaoyun School of Physics and Electronic Engineering Northwest Normal UniversityLanzhou 730070China

Aiming at the existing semantic segmentation process due to the loss of pixel features and the complexity of calculating too many parameters,which leads to unsatisfactory segmentation results and too long time,this paper proposes a lightweight semantic segmentation algorithm based on the fusion of multiple *** algorithm is based on the pyramid scene parsing network(PSPNet).Firstly,Mobile Net V2 network is chosen as the feature extraction network to construct the lightweight network structure.

关键词： Net network algorithm

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The characteristics of clusters of weather and extreme climate events in China during the past 50 years

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Chinese Physics B 2012年第1期21卷 549-557页

作者： Yang Ping Hou Wei Feng guo-Lin Institute of Urban Meteorology China Metrology AdministrationBeijing 100089China Laboratory for Climate Studies China Meteorological AdministrationBeijing 100081China

The pick-up algorithm by the k-th order cluster for the closest distance is used in the fields of weather and climactic events, and the technical terms clustered index and high clustered region are defined to investigate their temporal and spatial distribution characteristics in China during the past 50 years. The results show that the contribution of extreme high-temperature event clusters changed in the period from the 1960s to the 1970s, and its strength was enhanced. On the other hand, the decreasing trend in the clusters of low-temperature extremes can be taken as a signal for warmer winters to follow in the decadal time scale. Torrential rain and heavy rainfall clusters have both been lessened in the past 50 years, and have different cluster characteristics because of their definitions. Regions with high clustered indexes are concentrated in southern China. The spatial evolution of the heavy rainfall clusters reveals that clustered heavy rainfall has played an important role in the rain-belt pattern over China during the last 50 years.

关键词： extreme event clusters decadal clustered index

Thermal management of space stations

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Chinese Science Bulletin 2001年第23期46卷 2019-2024页

作者： Zengyuan guo Xingang Liang Xinrong Zhang Tsing Hua Univ Dept Engn Mech Beijing 100084 Peoples R China

Thermal management aims at making full use of energy resources available in the space station to reduce energy consumption, waste heat rejection and the weight of the station. It is an extension of the thermal control. This discussion introduces the concept and development of thermal management, presents the aspects of thermal management and further extends its application to subsystems of the space station.

关键词： space station thermal management thermal control environmental control and life support system.

New concept on coal structure and new consideration for the generation mechanism of oil from coal

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Chinese Science Bulletin 1998年第24期43卷 2025-2035页

作者： Kuangzong Qin Shaohui guo Shuyuan Li Univ Petr Beijing 100083 Peoples R China

The traditional two_phase structural model of coal based on the chemical covalence bonding has to be revised since recent discoveries of powerful mixed solvent such as CS-2/C-5H-9N, giving extra high yields in coal extraction at room temperature. It is believed that the physically associated interactions play important roles in the structure of coal. A composite model of coal is suggested. The organic matter of coal is mainly composed of some parts: the rigid 3_D macromolecules linked with chemical bonds; the polar molecules of high and moderate molecular weights, corresponding to asphaltenes and resins; the hydrocarbons with lower molecular weights. The polar molecules are associated by physical interactions (such as hydrogen bonding, charge transfer interactions, π_π interactions of aromatic sheets, etc.) each other and with macromolecules to form the network structure, in which some smaller nonpolar molecules are trapped. Based on the new concept of the composite coal model, some considerations for the generation mechanism of oil from coal have approached. Since the energy level of physical association is much lower than the chemical covalent bonding, the upper threshold of oil window for the generation of oil from coal seems not to be limited strictly after the theory of oil generation at the latter stage of the kerogen maturation. It looks reasonable to pay more attention to the geological conditions including the salt, water, minerals and environments of the sedimentation. The evolution process of physically associated interactions in the composite structure of coal and the generation of oil is thought to be intimately influenced by these factors.

关键词： Oil from coal coal structure generation mechanism of oil

Monte Carlo simulation of thermodynamic properties for two-dimensional Lennard-Jones fluids

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Chinese Science Bulletin 2000年第21期45卷 2004-2009页

作者： Xiaoli Feng Zhixin Li Zengyuan guo Tsing Hua Univ Dept Engn Mech Beijing 100084 Peoples R China

Canonical ensemble Monte Carlo simulations have been carried out to investigate thethermodynamic properties of two-dimensional fluids subjected to truncated Lennard-Jones 12-6 potential. The simulations of thermodynamic states sweep across liquid-vapor regime over a wide range of thermodynamic conditions. Simulated isotherms behave van der Waals loop-like characteristics in the liquid-vapor phase-transition region. It suggests a continuous isothermal phase transition in the case of micro system, in which the system size prohibits phase separation. Two-dimensional dimensionless van der Waals equation of states has been obtained from theoretical analysis. By fitting simulated data to this equation, temperature-dependent parameters in the equation have been determined.

关键词： Monte Carlo simulation thermodynamic properties isotherm liquid-vapor transition.

The zone-particle model for building fire simulation

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Chinese Science Bulletin 2010年第26期55卷 3060-3065页

作者： guo ShaoDong YANG Rui ZHANG Hui Center for Public Safety Research Department of Engineering Physics Tsinghua University Beijing 100084 China Department of Engineering Mechanics School of Aerospace Tsinghua University Beijing 100084 China

An effective fire and smoke propagation model is important for evaluating building safety, indicating safe rescue paths in emergencies, and determining proper control strategies. In this paper, a new model to simulate smoke propagation and to characterize mixing behavior is developed. In this model, a function considering the mixing behavior between the hot smoke and cool air is introduced to better resolve the temperature and smoke profiles in the vertical direction. Smoothed particle hydrodynamics (SPH) approach is used to obtain the function distribution through reconstructing velocities of marker particles and determining locations of particles in each layer in the zone model. The fundamentals of the model are presented in detail in this paper. A test (a simple building with experimental data and CFD simulation) is used to verify the model, in which experimental data and CFD simulations are compared to predictions from the new model and those from a two-layer model implemented using CFAST (Consolidated Model of Fire and Smoke Transport, developed by NIST). Favorable agreement of the new model results is seen with experiment data or CFD simulations. The new model also provides more accurate prediction of temperature distribution in comparison to the two-layer model.

关键词：建筑物安全粒子模型火灾模拟 CFD模拟实验数据空气混合分布预测流体动力学

Physical quantity synergy in laminar flow field of convective heat transfer and analysis of heat transfer enhancement

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Chinese Science Bulletin 2009年第19期54卷 3579-3586页

作者： LIU Wei LIU ZhiChun guo ZengYuan School of Energy and Power Engineering Huazhong University of Science and Technology Wuhan 430074 China School of Aerospace Tsinghua University Beijing 100084 China

Based on the principle of field synergy for heat transfer enhancement, the concept of physical quantity synergy in the laminar flow field is proposed in the present study according to the physical mechanism of convective heat transfer between fluid and tube wall. The synergy regulation among physical quantities of fluid particle is revealed by establishing formulas reflecting the relation between synergy angles and heat transfer enhancement. The physical nature of enhancing heat transfer and reducing flow resistance, which is directly associated with synergy angles α, β, γ, φ, θ and ψ, is also explained. Besides, the principle of synergy among physical quantities is numerically verified by the calculation of heat transfer and flow in a thin cylinder-interpolated tube, which may guide the optimum design for better heat transfer unit and high-efficiency heat exchanger.

关键词：对流换热过程广义热阻耗散进展

Numerical simulation of solidification and liquation behavior during welding of low-expansion superalloys

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Frontiers of Materials Science 2011年第2期5卷 146-159页

作者： Shao-Qing guo Xiao-Hong LI Beijing Institute of Aeronautical Materials Beijing 100095 China

Low-expansion superalloys are susceptible to weld solidification cracks and heat,affected zone （HAZ）microflssures. To predict solidification cracking, QBasic procedures were developed and solidification reaction sequence, type, and amount of eutectic product were caiculated As manifested, primary solidification is followed by L→（Y＋ NbC） and L → （Y＋ Laves） eutectic reaction sequentially for G H903 and GH907; hence, the terminal eutectic constitue Y/Laves, While for GH909, intsare made up of Y/NbC and Y/only reaction L → （Y ＋ Laves） occurs and more Y/Laves eutectic forms. Therefore, GH909is more sensitive to solidification cracking. To predict HAZ liquation, cracking Visual FORTRAN procedures were developed, and constitutional liquation of NbC was simulated. As shown, solid dissolution of NbC prior to liquation decreases, and initial liquid film increases with the rate of thermal cycle. Higher rate of thermal cycle promotes the melting of the matrix adjacent to the liquid film and postpones the solidification of the at the eutectic n size and peak rifled indirectly by hot ductility tests.

关键词： solidification cracking HAZ microfissuring constitutional liquation lowexpansion superalloy numerical simulation

Simulation research for mobile robot path planning based on improved artificial potential field method recommended by the AsiaSim

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International Journal of Modeling, Simulation, and Scientific Computing 2017年第2期8卷 241-254页

作者： Pengqi Hou Hu Pan Chen guo School of Information Science and Technology Dalian Maritime University P.R.China

Mobile robot path planning is an important research branch in the field of mobile *** main disadvantage of the traditional artificial potential field(APF)method is prone to local minima *** artificial potential field(IAPF)method is presented in this paper to solve the problem in the traditional APF method for robot path planning in different *** introduce the distance between the robot and the target point to the function of the original repulsive force field and change the original direction of the repulsive force to avoid the trap problem caused by the local minimum *** IAPF method is suitable for mobile robot path planning in the complicated *** and experiment results at the robot platform illustrated the superiority of the modified IAPF method.

关键词： Artificial potential field method mobile robot path planning local minimum point simulation.