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Effect Factor Analysis of Spraying Quality for Agricultural Chemicals
Wenfeng Sun,Qichao Li,Yongcun Fan,Yanhua Wan,Teng Wang,Baozhong Cong 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.11
As one of the most important parts of the agricultural work, agricultural chemicals spray is to protect the plants from weeds, pest and bacteria. With development of high efficient agricultural chemicals, the consumption of agricultural chemicals should be controlled within a couple of liter per hectare in theory. But it’s very hard to realize effective use of agricultural chemicals in fact. In this paper, the most effect factors of spray quality such as droplets size, environment temperature, droplets density, nozzle type and spray method were analyzed in agricultural chemicals spray operation. Droplet size effects drift and uniformity of droplet distribution directly. Environment temperature effects drift and uniformity of droplet distribution greatly. Character of nozzle affects spraying quality directly. All research of the paper can offer valuable reference to appropriate application of agricultural chemicals.
Analysis of the Three-Way Decision Rules in Online Learning-Taking a Calculus Course as an Example
Songlin Yang,Ting Xu,Yongcun Shao 한국지능시스템학회 2022 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.22 No.2
To investigate the credibility of online examinations, we randomly chose 30 engineering students in Wenzheng College of Soochow University as a sample and established an informationsystem S. According to pedagogy theory, students’scores are related to their intelligencelevels, course basis, learning methods, and learning time. Therefore, in the information systemS, “score of early semester,” “average score of class quizzes,” “completion ratio of watchingvideos,” and “completion grade of homework” were taken as the condition attributes, and“score of final exam” was taken as the decision attribute. We applied the three-way decisionrules theory to provide positive, negative, and boundary decision rules for this informationsystem S. Furthermore, we obtained confidence in the decision rules. The results of this studyvalidate the credibility of online examinations and have certain guiding significance for onlineteaching and learning.
Detection of Starch Content in Potato Based on Hyperspectral Imaging Technique
Wei Jiang,Junlong Fang,Shuwen Wang,Yongcun Fan 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.12
Detection of starch content in potato is studied applying hyperspectral imaging technique in the paper. The original and preprocessing spectra were processed with partial least square(PLS) method to build prediction model of starch content. The original spectra between 400 and 1000nm was preprocessed with smoothing, second derivation, and multiplicative scatter correction (MSC). Prediction model was built with preprocessing spectra by applying principal component analysis (PCA). Known from the result, the model based on the preprocessing spectra preprocessed with smoothing and PCA is the best of all prediction models built in research. The determination coefficient (R2)of calibration set and prediction set was 0.8234 and 0.9031 respectively. The root mean square error of calibration set (RMSEC) and root mean square error of validation set(RMSEV) was 0.5633 and 0.5025,respectively.It indicated that this method could be applied in detection of starch content in potato. The study could offer theoretical and practical reference for further study in the future.
Modelling and Experimental Study of Halbach Array Magnetic Coupler
De-yong Li,Shuang Wang,Yongcun Guo,Xin Ma 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.1
In order to effectively solve the current problems of magnetic couplers such as large area and complex internal coil, the Halbach array magnetic coupler was proposed. According to the specific characteristics of the hybrid magnetic coupler structure, the mathematical model of air gap magnetic flux density is established by using the combination of electric circuit and electromagnetic field solution. Based on the current superposition, the current is converted to the surface of the copper conductor, and the electromagnetic torque model of the space magnetic field is established by integrating the induced electromotive force along the circumferential direction. In order to verify the correctness of theoretical analysis, the 1:4 prototype was designed and manufactured. Then simulation verification and experiment measurement on its mechanical behaviour are performed. The results show that the maximum error of theoretical value, simulation value and test value is 9.3%. Under the same volume size, the output torque of Halbach array magnetic coupler is increased by 16.1% compared with the ordinary disk magnetic coupler. The research could provide the reference for the design and experimental research of magnetic coupler.
Numerical analysis of stress wave of projectile impact composite laminate
Zhangxin Guo,Weijing Niu,Junjie Cui,Gin Boay Chai,Yongcun Li,Xiaodong Wu 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.87 No.2
The three-dimensional Hashin criterion and user subroutine VUMAT were used to simulate the damage in the composite layer, and the secondary stress criterion was used to simulate the interlayer failure of the cohesive element of the bonding layer and the propagation characteristics under the layer. The results showed that when the shear stress wave (shear wave) propagates on the surface of the laminate, the stress wave attenuation along the fiber strength direction is small, and thus producing a large stress profile. When the compressive stress wave (longitudinal wave) is transmitted between the layers, it is reflected immediately instead of being transmitted immediately. This phenomenon occurs only when the energy has accumulated to a certain degree between the layers. The transmission of longitudinal waves is related to the thickness and the layer orientation. Along the symmetry across the thickness direction, the greater is the stress amplitude along the layer direction. Based on the detailed investigation on the impact on various laminated composites carried out in this paper, the propagation characteristics of stress waves, the damage and the destruction of laminates can be explained from the perspective of stress waves and a reasonable layering sequence of the composite can be designed against damage and failure from low velocity impact.
Comparison of Chlorophyll Algorithms in the Bohai Sea of China
Peng Xiu,Yuguang Liu,Zengrui Rong,Haibo Zong,GangLi,Xiaogang Xing,Yongcun Cheng 한국해양과학기술원 2007 Ocean science journal Vol.42 No.4
Empirical band-ratio algorithms and artificial neural network techniques to retrieve sea surface chlorophyll concentrations were evaluated in the Bohai Sea of China by using an extensive field observation data set. Bohai Sea represents an example of optically complex case II waters with high concentrations of colored dissolved organic matter (CDOM). The data set includes coincident measurements of radiometric quantities and chlorophyll a concentration (Chl), which were taken on 8 cruises between 2003 and 2005. The data covers a range of variability in Chl in surface waters from 0.3 to 6.5 mg m-3. The comparison results showed that these empirical algorithms developed for case I and case II waters can not be applied directly to the Bohai Sea of China, because of significant biases. For example, the mean normalized bias (MNB) for OC4V4 product was 1.85 and the root mean square (RMS) error is 2.26.
Xu, Wenhua,Wang, Shunli,Fernandez, Carlos,Yu, Chunmei,Fan, Yongcun,Cao, Wen The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.6
Accurate estimation of the lithium-ion battery state of charge plays an important role in the real-time monitoring and safety control of batteries. In order to solve the problems that the real-time estimation of the lithium-ion battery is difficult and the estimation accuracy is not high under various working conditions, a lithium-ion battery is taken as a research object, and the working characteristics of the lithium-ion battery are studied under various working conditions. In order to reduce the computational complexity of the traditional unscented Kalman algorithm, an improved unscented Kalman algorithm is proposed. Considering the importance of accurately estimating the initial state of charge for later estimation, the initial estimation value is calibrated by using the open-circuit voltage method. Then, the improved unscented Kalman filter algorithm based on a reduced-order model is used for assessing and tracking to realize real-time high-precision estimation of the state of charge of the lithium-ion battery. A simulation model is built and combined with a variety of working conditions data for performance analysis. The experimental results show that the convergence speed and tracking effect are good and that the estimation error control is within 0.8%. It is verified that the reduced order of the three-particle nonlinear transform unscented Kalman results in higher accuracy in the state-of-charge estimation of lithium-ion batteries.
Comparison of Chlorophyll Algorithms in the Bohai Sea of China
Xiu, Peng,Liu, Yuguang,Rong, Zengrui,Zong, Haibo,Li, Gang,Xing, Xinogang,Cheng, Yongcun The Korean Society of Oceanography 2007 Ocean science journal Vol.42 No.4
Empirical band-ratio algorithms and artificial neural network techniques to retrieve sea surface chlorophyll concentrations were evaluated in the Bohai Sea of China by using an extensive field observation data set. Bohai Sea represents an example of optically complex case II waters with high concentrations of colored dissolved organic mattei (CDOM). The data set includes coincident measurements of radiometric quantities and chlorophyll a concentration (Chl), which were taken on 8 cruises between 2003 and 2005, The data covers a range of variability in Chl in surface waters from 0.3 to 6.5 mg $m^{-3}$. The comparison results showed that these empirical algorithms developed for case I and case II waters can not be applied directly to the Bohai Sea of china, because of significant biases. For example, the mean normalized bias (MNB) for OC4V4 product was 1.85 and the root mean square (RMS) error is 2.26.