作者机构:
[Yayi Huang; Changhua Liu] School of Mathematics and Computer Science, Wuhan Polytechnic University, Wuhan, Hubei, 4300232, China;[Qiming Ma; Xiaoming Wu; Hao Li; Kun Xu; Gaoxiang Ji; Fang Qian; Lixia Li; Qian Huang; Ying Long; Xiaojun Zhang; Biyun Chen] Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory for Oil Crop Biology and Genetic Improvement, Ministry of Agriculture, Wuhan, Hubei Province, 430062, China
通讯机构:
[Biyun Chen] O;[Changhua Liu] S;Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory for Oil Crop Biology and Genetic Improvement, Ministry of Agriculture, Wuhan, Hubei Province, 430062, China<&wdkj&>School of Mathematics and Computer Science, Wuhan Polytechnic University, Wuhan, Hubei, 4300232, China
摘要:
The chlorophyll content has a direct effect on photosynthesis of crops. In order to explore a quick and convenient method for estimating the chlorophyll content of Brassica napus and facilitate efficient crop monitoring, we measured the actual value of chlorophyll with a SPAD-502 chlorophyll detector, and collected aerial images of B. napus with an unmanned aerial vehicle(UAV) carrying a RGB camera in this study. The total number of 270 samples collected images were divided into regions according to the planting conditions of different B. napus varieties in the field. Then, according to the empirical formula, there were 36 colors’ characteristic parameters calculated and combined. To estimate the chlorophyll content of rape, 189 samples were included in the modeling set, while the other 81 samples were enrolled in the validation set for testing the accuracy of this model. After the combination of R (red), G (green) and B (blue) color channels, the results showed that the color characteristics B/(R + G), b, B/G, (G-B)/(G + B), g-b were highly connected with the measured value of chlorophyll SPAD, and the correlation coefficient between the combination based on B/(R + G) and SPAD value was 0.747. With R2 = 0.805, RMSE = 3.343, and RE = 6.84%, the regression model created using random forest had superior outcomes, according to the model comparison. This study offers a new method for quickly estimating the amount of chlorophyll in rapeseed and a workable reference for crop monitoring using the UAV platform.
作者机构:
[Bian, Dong-fen] Beijing Inst Technol, Sch Math & Stat, Beijing 100081, Peoples R China.;[Fan, Li-li] Wuhan Polytech Univ, Sch Math & Comp Sci, Wuhan 430023, Hubei, Peoples R China.;[He, Lin] Chinese Acad Sci, Acad Math & Syst Sci, Inst Appl Math, Beijing 100190, Peoples R China.;[Zhao, Hui-jiang] Wuhan Univ, Sch Math & Stat, Wuhan 430072, Hubei, Peoples R China.;[Zhao, Hui-jiang] Wuhan Univ, Computat Sci Hubei Key Lab, Wuhan 430072, Hubei, Peoples R China.
通讯机构:
[Bian, Dong-fen] B;Beijing Inst Technol, Sch Math & Stat, Beijing 100081, Peoples R China.
关键词:
compressible Navier-Stokes equations;inflow problem;viscous shock wave;large density oscillations
摘要:
This paper is concerned with the inflow problem for one-dimensional compressible Navier-Stokes equations. For such a problem, Huang, Matsumura, and Shi showed in [4] that there exists viscous shock wave solution to the inflow problem and both the boundary layer solution, the viscous shock wave, and their superposition are time-asymptotically nonlinear stable provided that both the initial perturbation and the boundary velocity are assumed to be sufficiently small. The main purpose of this paper is to show that similar stability results still hold for a class of large initial perturbation which can allow the initial density to have large oscillations. The proofs are given by an elementary energy method and our main idea is to use the smallness of the strength of the viscous shock wave and the boundary velocity to control the possible growth of the solutions induced by the nonlinearity of the compressible Navier-Stokes equations and the inflow boundary condition. The key point in our analysis is to deduce the desired uniform positive lower and upper bounds on the density.
作者机构:
[张帆; 张聪] School of Mathematics &, Computer Science, Wuhan Polytechnic University, Wuhan, 430023, China;[徐明迪] Wuhan Digital and Engineering Institute, Wuhan, 430205, China;[陈伟] School of Computer Science and Technology, Nanjing University of Posts and Telecommunications, Nanjing, 210046, China;[胡方宁; 张帆] School of Electrical and Computer Engineering, Jacobs University Bremen, Bremen, 28759, Germany
通讯机构:
Wuhan Digital and Engineering Institute, Wuhan, China
作者机构:
[张帆; Chao, Han-Chieh; 张聪] School of Mathematics &, Computer Science, Wuhan Polytechnic University, Wuhan, 430023, China;[刘小丽] College of Cyber Security, Jinan University, Guangzhou, 510632, China;[刘小丽] College of Information Science and Technology, Jinan University, Guangzhou, 510632, China;[Chao, Han-Chieh] Department of Computer Science and Information Engineering, Ilan University, Ilan, 02415271, Taiwan;[Chao, Han-Chieh] Department log Electrical Engineering, Dong Hwa University, Hwalian, 08153719, Taiwan