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Modeling dynamics of Leaf Color Based on RGB Value in Rice

Journal of Integrative Agriculture 2014年第4期13卷 749-759页

作者： ZHANG Yong-hui TANG Liang LIU Xiao-jun LIU Lei-lei CAO Wei-xing ZHU Yan National Engineering and Technology Center for Information Agriculture Ministry of Industry and Information Technology/Jiangsu Key Laboratory for Information Agriculture/College of AgricultureNanjing Agricultural University

This paper was to develop a model for simulating the leaf color changes in rice （Oryza sativa L.） based on RGB （red, green, and blue） values. Based on rice experiment data with different cultivars and nitrogen （N） rates, the time-course RGB values of each leaf on main stem were collected during the growth period in rice, and a model for simulating the dynamics of leaf color in rice was then developed using quantitative modeling technology. The results showed that the RGB values of leaf color gradually decreased from the initial values （light green） to the steady values （green） during the first stage, remained the steady values （green） during the second stage, then gradually increased to the final values （from green to yellow） during the third stage. The decreasing linear functions, constant functions and increasing linear functions were used to simulate the changes in RGB values of leaf color at the first, second and third stages with growing degree days （GDD）, respectively; two cultivar parameters, MatRGB （leaf color matrix） and AR （a vector composed of the ratio of the cumulative GDD of each stage during color change process of leaf n to that during leaf n drawn under adequate N status）, were introduced to quantify the genetic characters in RGB values of leaf color and in durations of different stages during leaf color change, respectively; FN （N impact factor） was used to quantify the effects of N levels on RGB values of leaf color and on durations of different stages during leaf color change; linear functions were applied to simulate the changes in leaf color along the leaf midvein direction during leaf development process. Validation of the models with the independent experiment dataset exhibited that the root mean square errors （RMSE） between the observed and simulated RGB values were among 8 to 13, the relative RMSE （RRMSE） were among 8 to 10%, the mean absolute differences （da） were among 3.85 to 6.90, and the ratio of da to the mean observation values （Clap

关键词： rice leaf color RGB dynamic simulation visualization

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Performance Analysis on Retractable Landing Gear and Design of Ground Test System

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第6期33卷 -页

作者： Wang Hongxian Nie Hong Key Laboratory of Unmanned Aerial Vehicle Technology of Ministry of Industry and Information Technology Nanjing University of Aeronautics and Astronautics State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics

Landing gears are one of the key components for large or middle unmanned aerial vehicles,and their working performances directly affect flying security and aircraft taking-off and landing ***,it is meaningful to study the retraction *** on CATIA and ADAMS software platforms,a virtual model of landing gear retraction system is built for performance test,and then dynamic simulation is carried ***,a test system for landing gear retraction is established,and the test data are compared with the results acquired from dynamics *** main factors which affect the dynamic performance of retractable landing gear are analyzed *** simulation results show that aerodynamic load has an impact on retraction time,the mass force affects extension process,and the oil hole size of hydraulic actuator has an effect on both retraction time and extension time.

关键词： landing gear retraction system dynamic simulation experiment system

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dynamic characteristics of cold rolling mill and strip based on flatness and thickness control in rolling process

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Journal of Central South University 2014年第2期21卷 567-576页

作者：孙建亮彭艳刘宏民 National Engineering Research Center for Equipment and Technology of Cold Strip Rolling (Yanshan University) State Key Laboratory of Metastable Materials Science and Technology (Yanshan University) School of Mechanical Engineering University of Science & Technology Beijing

The dynamic model of cold rolling mill based on strip flatness and thickness integrated control was proposed,containing the following sub-models:the rolling process model,the dynamic model of rolls along axial direction,and the compensation *** on the rule of volume flow rate,the dynamic rolling process model was *** work roll and backup roll were taken as elastic continuous bodies,the effect of shear and moment of inertia were taken into consideration,and then the dynamic model of rolls was *** two models were coupled together,and the dynamic model of rolling mill was *** the dynamic model,the thermal expansion of the rolls,the wear of the rolls and other related parameters can not be *** order to compensate the dynamic model,the coupled static model of rolls and strip was ***,according to the inner relationship of these models,the dynamic model and the compensation model were coupled,and the dynamic model of rolling mill based on the strip flatness and thickness integrated control was *** dynamic simulation of the rolling process was made,and the dynamic thickness and the dynamic flatness information were *** model not only provides a theory basis for the virtual rolling,but also provides a platform for the application of advanced control theory.

关键词： cold rolling dynamic simulation strip flatness strip thickness transverse vibration

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Modelling and analysis of parameters of vacuum tube solar collector with U-shaped tube for different climates

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Clean Energy 2023年第3期7卷 519-531页

作者： Ghassan Fadhil Smaisim Azher M.Abed Salema K.Hadrawi Farnaz Jahanbin Department of Mechanical Engineering Faculty of EngineeringUniversity of Kufa54001Iraq Nanotechnology and Advanced Materials Research Unit(NAMRU) Faculty of EngineeringUniversity of Kufa54001Iraq Department of Air Conditioning and Refrigeration Al-Mustaqbal University CollegeBabylon51001Iraq Refrigeration and Air-conditioning Technical Engineering Department College of Technical EngineeringThe Islamic UniversityNajaf54001Iraq Department of Chemistry Mashhad BranchIslamic Azad UniversityMashhadIran

In this study,based on the energy balance for different components of a double-layered vacuum-tube solar collector with a U-tube,the thermal performance of the collector unit is investigated separately using an analytical and quasi-dynamic *** model used in this study determines the temperature distribution in longitudinal and radial *** this research,the effects of physical parameters and heat transfer including the size of the collector,thermal-loss coefficient,absorption coefficient,mass flow and thermal resistance of the air layer under different climate conditions have been evaluated on the performance of the vacuum-tube *** results showed that by increasing the diameter of the tube with constant length,the annual thermal efficiency of the collector ***,in a fixed-diameter tube,with increasing tube length,the annual efficiency increases,but this increase is meagre for lengths of>1.5 *** optimal mass flow rate for maximum efficiency has been obtained for cities with different *** to the results,the optimal flow for different climates has different values that can be optimized as a relationship between the average solar radiation annually as a symbol of temperature and flow.

关键词： solar-thermal energy solar radiation vacuum tube dynamic simulation sustainable development

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Thermal Loss Analysis of a Flat Plate Solar Collector Using Numerical simulation

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Computers, Materials & Continua 2022年第12期73卷 4627-4640页

作者： Timur Merembayev Yedilkhan Amirgaliyev Murat Kunelbayev Didar Yedilkhan Institute of Information and Computational Technologies CS MES RK AlmatyKazakhstan International Information Technology University AlmatyKazakhstan Al-Farabi Kazakh National University AlmatyKazakhstan Astana IT University Nur-SultanKazakhstan

In this paper,we studied theoretically and numerically heated losses of a flat solar collector to model the solar water heating system for the Kazakhstan climate *** different climatic zones with a growing cost for energy or lack of central heating systems,promising is to find ways to improve the energy efficiency of the solar *** mathematical model(based on ordinary differential equation)simulated the solar system work process under different *** bridge the modeling and real values results,we studied the important physical parameters such as loss coefficient,Nu,Ra,and Pr *** impacted the efficiency of flat solar collectors and heat losses of the *** developed mathematical models,the design and composition of the software and hardware complex,and automated control and monitoring systems allow solar hot water heating systems to increase the energy efficiency of life support systems and heat supply of buildings by reducing energy consumption for heat *** simulation result showed that during the daytime,the temperature of water in the collector is 70°C;the storage of heated water since heated water is cooled at *** defined that a work period of the system can be extended with high efficiency(April-October)for Almaty region.

关键词： Solar heating system heat loss coefficient dynamic simulation flat plate collector

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Deviation Prevention Ability of Rollers in Continuous Annealing Furnace and Application

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Journal of Iron and Steel Research International 2012年第12期19卷 8-13页

作者： ZHANG Yan YANG Quan HE An-rui YAO Xi-jiang GUO De-fu National Engineering Research Center of Advanced Rolling University of Science andTechnology Beijing Beijing 100083 China

In order to reduce the strip deviation in the practical production procedure in the continuous annealing fur- nace, a dynamic simulation model was built through finite element method （FEM） to conduct the quantification cal- culation of the effect of regular roller contour types on strip deviation. The result reveals that comparing to the flat roller, forward roller contour can prevent the strip deviation to some degree. In terms of prevention ability, double- taper roller is the strongest, single-taper roller and crown roller are less stronger; and more roller contour values raise the prevention ability. Accordingly, optimization method was applied to continuous annealing furnace, and it largely reduced accidents such as strip break and limited speed that are caused by the deviation.

关键词： strip deviation continuous annealing furnace dynamic simulation roller contour

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Geo-engineered buffer capacity of two-layered absorbing system under the impact of rock avalanches based on Discrete Element Method

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Journal of Mountain Science 2016年第5期13卷 917-929页

作者： BI Yu-zhang HE Si-ming LI Xin-po WU Yong XU Qiang OUYANG Chao-jun SU Li-Jun WANG Hao Key Laboratory of Mountain Hazards and Earth Surface Process Chinese Academy of Sciences Institute of Mountain Hazards and Environment Chinese Academy of Sciences & Water Resources Ministry Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences State Key Laboratory of Geo-Hazard Prevention and Geo-Environment Protection Chengdu University of Technology College of Environment and Resources Fuzhou University

Many rock avalanches were triggered by the Wenchuan earthquake on May 12, 2008 in southwest China. Protection galleries covered with a single soil layer are usually used to protect against rockfall. Since one-layer protection galleries do not have sufficient buffer capacity, a two-layered absorbing system has been designed. This study aims to find whether an expanded poly-styrol （EPS） cushion, which is used in the soil-covered protection galleries for shock absorption, could be positioned under dynamic loadings. The dynamic impacts of the two-layered absorbing system under the conditions of rock avalanches are numerically simulated through a 2D discrete dement method. By selecting reasonable parameters, a series of numerical experiments were conducted to find the best combination for the two- layered absorbing system. The values of the EPS layer area as a percentage of the total area were set as 0% （Sl）, 22~ （S2）, and 70% （$3）. 22~ of the area of the EPS layer was found to be a reasonable value, and experiments were conducted to find the best position of the EPS layer in the two-layered absorbing system. The numerical results yield useful conclusions regarding the interaction between the impacting avalanches and the two-layered absorbing system. The soil layer can absorb the shock energy effectively and S2 （0.4-m thick EPS cushion covered with soil layer） is the most efficient combination, which can reduce the impact force, compared with the other combinations.

关键词： Discrete element method Buffer capacity dynamic simulation Impact force Two-layered absorbing system

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On Trajectory Splitting for Accelerating dynamic simulations in Mobile Wireless Networks

On Trajectory Splitting for Accelerating Dynamic Simulations...

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The 19th International Teletraffic Congress-ITC19

作者： S-E. Elayoubi B. Fourestié France Télécom R＆D 38-40 rue du Général Leclerc-92130 Issy Les Moulineaux-France France Télécom R＆D 38-40 rue du Général Leclerc-92130 Issy Les Moulineaux-France

＜正＞This paper presents a method to enhance dynamic simulation performance in mobile networks. The aim is to accelerate the estimation of blocking and dropping probabilities by reducing the variances of the estimators. We adopt a Trajectory Splitting method that splits the path of the simulated stochastic process into multiple copies when the station loads cross predetermined thresholds, thus focusing on configurations for which communication problems are likely to occur. We show that this method significantly reduces the variance of the estimators of both blocking and dropping probabilities. In a real network dynamic simulation, we propose an algorithm to first check the convergence of the network towards its steady state distribution and discard the initial stabilization samples, and second apply Trajectory Splitting to accelerate simulations.

关键词： dynamic simulation mobile networks variance reduction convergence diag- nostic.

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Interrelations Between Socio-economic Development and Environmental Quality:a simulation Integrating System dynamics Models with GIS

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Geo-Spatial Information Science 2005年第3期8卷 176-182页

作者： YU Jie BIAN Fuling PETERSON Jim LI Pingxiang School of Remote Sensing and Information Engineering Wuhan University 129 Luoyu Road Wuhan 430079 China.

System dynamics (SD) theory has long been deployed in modeling complex non-linear interrelationships but, so far it has not been common to do the kind of modeling in support of bringing environmental sustainability policies to practice. This is largely because the challenge of including spatial data has not yet been well met. Potential for adoption of SD and GIS methods in combination is exemplified with the results of a decision-support exercise designed for simulation and prediction of the dynamic inter-relationships between socio-economic development and environmental quality for the "Wen, Pi, Du" county in Sichuan province, southwestern China.

关键词： system dynamics GIS dynamic simulation eco-economic system SD model analytic hierarchy process

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Analysis of influence of the length of ground heat exchangers on the operation characteristics and economy of ground source heat pumps

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Energy and Built Environment 2021年第2期2卷 127-136页

作者： Hongzhi Zhang Zongwei Han Lingyan Yang Jiawei Yuan Xinlu Cheng Mingzhen Ji Gui Li SEP Key Laboratory of Eco-Industry School of MetallurgyNortheastern UniversityShenyang 110819China China Academy of Building Research Beijing 100013China

A three-dimensional finite element dynamic simulation platform of the ground source heat pump system(GSHPS)is *** to the outlet temperature of ground heat exchangers(GHEs)required by the code in summer and winter,the calculated minimum buried depth of GHEs meeting the requirements is 60 m,when the number of borehole is *** using the established platform,the annual operation performance and cost of the GSHPS under different buried pipe depths are *** results show that the deeper the buried depth of GHEs is,the better the heat exchange effect of GHEs *** with the GHEs with 60 m buried depth,when the buried depth of GHEs is 65 m,70 m,75 m and 80 m,the average coefficient of performance(COP)of the unit increases by 4.1%,6.3%,7.7%and 8.2%in cooling period and 1.0%,1.6%,1.8%and 1.9%in heating period,*** the performance and initial investment of the GHSPS comprehensively,the optimal buried depth of GHEs is 60 ***,considering the performance the system and the total cost of the system running for 20 years comprehensively,the optimal buried depth of GHEs is 70 m.

关键词： Buried depth dynamic simulation Coefficient of performance Economic analysis

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