本研究利用基于有界平均振荡模型(boundary mean oscillation, BMO)的ZQ梯度算子,结合各向异性非线性偏微分方程模型,构造用于图像处理的BMO滤波器,对水稻谷粒的数字图像进行去噪增强、边缘检测和特征提取,并对粒形参数进行统计分析。...本研究利用基于有界平均振荡模型(boundary mean oscillation, BMO)的ZQ梯度算子,结合各向异性非线性偏微分方程模型,构造用于图像处理的BMO滤波器,对水稻谷粒的数字图像进行去噪增强、边缘检测和特征提取,并对粒形参数进行统计分析。在此基础上,比较了BMO滤波与中值滤波的处理效果,并分析了BMO滤波技术的准确性与稳定性。结果表明,BMO滤波在保留图像的边界与细节特征方面显著优于中值滤波,其处理图像获取的谷粒粒长、粒宽和长宽比与人工测量值无显著差异(p <0.05),平均粒面积与千粒重正相关性强(R2 = 0.942, p <0.001),且粒形参数提取结果在不同水稻品种间有较好的稳定性。展开更多
The radial basis function （RBF） emerged as a variant of artificial neural network. Generalized regression neural network （GRNN） is one type of RBF, and its principal advantages are that it can quickly learn and ra...The radial basis function （RBF） emerged as a variant of artificial neural network. Generalized regression neural network （GRNN） is one type of RBF, and its principal advantages are that it can quickly learn and rapidly converge to the optimal regression surface with large number of data sets. Hyperspectral reflectance （350 to 2500 nm） data were recorded at two different rice sites in two experiment fields with two cultivars, three nitrogen treatments and one plant density （45 plants m^-2）. Stepwise multivariable regression model （SMR） and RBF were used to compare their predictability for the leaf area index （LAI） and green leaf chlorophyll density （GLCD） of rice based on reflectance （R） and its three different transformations, the first derivative reflectance （D1）, the second derivative reflectance （D2） and the log-transformed reflectance （LOG）. GRNN based on D1 was the best model for the prediction of rice LAI and CLCD. The relationships between different transformations of reflectance and rice parameters could be further improved when RBF was employed. Owing to its strong capacity for nonlinear mapping and good robustness, GRNN could maximize the sensitivity to chlorophyll content using D1. It is concluded that RBF may provide a useful exploratory and predictive tool for the estimation of rice biophysical parameters.展开更多
A field study was conducted at CRIN Uhonmora Substation, Edo State in Derived Guinea Savanna Zone of Nigeria between 2007 and 2008. The experiment determined influence of intercropping cocoa with rice and plantain at ...A field study was conducted at CRIN Uhonmora Substation, Edo State in Derived Guinea Savanna Zone of Nigeria between 2007 and 2008. The experiment determined influence of intercropping cocoa with rice and plantain at early stage of field establishment. Four treatments considered were cocoa （sole）, cocoa/rice, cocoa/plantain and cocoa/rice/plantain. Spacing of 3.1 m apart was used for cocoa and plantain while rice was 30 cm. Plot laid out was randomized complete block design replicated three times. Data on cocoa morphological parameters comprising plant height, girth and leaf area as well as weed biomass were measured monthly. Cocoa survival count was also determined. Data collected were subjected to ANOVA, and LSD was used to separate the means. Survival count showed over 95% survival in all treatments without any significance differences. On plant height and leaf area vegetative growth were significantly higher （P 〈 0.05） in the intercrops than the sole cocoa but not significantly different in all the months. Plant vigour was significantly higher in cocoa/plantain intercrop. Cocoa/rice/plantain produced the least weed biomass while cocoa sole gave the highest. Therefore, cocoa/rice and cocoa/plantain intercrops could be recommended to cocoa farmers in Nigeria instead of sole planting at early age of field establishment.展开更多
Application of improper methods on rice processing affects rice quality and head rice recovery. In Vietnam, paddy with different moisture contents （from 13% to 17%） is dehusked by both rubber roll and stone disk. Th...Application of improper methods on rice processing affects rice quality and head rice recovery. In Vietnam, paddy with different moisture contents （from 13% to 17%） is dehusked by both rubber roll and stone disk. Thus, objective of this research was to evaluate the technical and economic aspects of the two methods. Optimization was conducted with 20 experiments for input factors （moisture content） and output factors （head brown rice recovery, specific energy consumption）. Besides, other factors were also monitored, such as the gap between the two disks, speed of disk and roll, and pressure of rubber roll on paddy. Test results showed that the maximum value of head brown rice （77.4%） and the minimum value of specific energy consumption （0.66 kWh/ton） corresponding to moisture content of paddy of 13.7% for stone disk dehusker. At similar moisture content （13.7%）, head brown rice recovery and specific energy consumption were 77.2% and 1.04 kWh/ton for rubber roll dehusker, respectively. As the result, specific energy consumption of rubber roll dehusker was higher than that of stone disk dehusker, corresponding to the higher dehusking efficiency.展开更多
Hyperspectral reflectance (350-2500 nm) measurements were made over two experimental rice fields containing two cultivars treated with three levels of nitrogen application.Four different transformations of the reflect...Hyperspectral reflectance (350-2500 nm) measurements were made over two experimental rice fields containing two cultivars treated with three levels of nitrogen application.Four different transformations of the reflectance data were analyzed for their capability to predict rice biophysical parameters,comprising leaf area index (LAI;m-2 green leaf area m-2 soil) and green leaf chlorophyll density (GLCD;mg chlorophyll m 2 soil),using stepwise multiple regression (SMR) models and support vector machines (SVMs).Four transformations of the rice canopy data were made,comprising reflectances (R),first-order derivative reflectances (D1),second-order derivative reflectances (D2),and logarithm transformation of reflectances (LOG).The polynomial kernel (POLY) of the SVM using R was the best model to predict rice LAI,with a root mean square error (RMSE) of 1.0496 LAI units.The analysis of variance kernel of SVM using LOG was the best model to predict rice GLCD,with an RMSE of 523.0741 mg m-2.The SVM approach was not only superior to SMR models for predicting the rice biophysical parameters,but also provided a useful exploratory and predictive tool for analyzing different transformations of reflectance data.展开更多
文摘本研究利用基于有界平均振荡模型(boundary mean oscillation, BMO)的ZQ梯度算子,结合各向异性非线性偏微分方程模型,构造用于图像处理的BMO滤波器,对水稻谷粒的数字图像进行去噪增强、边缘检测和特征提取,并对粒形参数进行统计分析。在此基础上,比较了BMO滤波与中值滤波的处理效果,并分析了BMO滤波技术的准确性与稳定性。结果表明,BMO滤波在保留图像的边界与细节特征方面显著优于中值滤波,其处理图像获取的谷粒粒长、粒宽和长宽比与人工测量值无显著差异(p <0.05),平均粒面积与千粒重正相关性强(R2 = 0.942, p <0.001),且粒形参数提取结果在不同水稻品种间有较好的稳定性。
基金Project supported by the National Natural Science Foundation of China (No.40571115)the National High Tech-nology Research and Development Program (863 Program) of China (Nos.2006AA120101 and 2007AA10Z205)
文摘The radial basis function （RBF） emerged as a variant of artificial neural network. Generalized regression neural network （GRNN） is one type of RBF, and its principal advantages are that it can quickly learn and rapidly converge to the optimal regression surface with large number of data sets. Hyperspectral reflectance （350 to 2500 nm） data were recorded at two different rice sites in two experiment fields with two cultivars, three nitrogen treatments and one plant density （45 plants m^-2）. Stepwise multivariable regression model （SMR） and RBF were used to compare their predictability for the leaf area index （LAI） and green leaf chlorophyll density （GLCD） of rice based on reflectance （R） and its three different transformations, the first derivative reflectance （D1）, the second derivative reflectance （D2） and the log-transformed reflectance （LOG）. GRNN based on D1 was the best model for the prediction of rice LAI and CLCD. The relationships between different transformations of reflectance and rice parameters could be further improved when RBF was employed. Owing to its strong capacity for nonlinear mapping and good robustness, GRNN could maximize the sensitivity to chlorophyll content using D1. It is concluded that RBF may provide a useful exploratory and predictive tool for the estimation of rice biophysical parameters.
文摘A field study was conducted at CRIN Uhonmora Substation, Edo State in Derived Guinea Savanna Zone of Nigeria between 2007 and 2008. The experiment determined influence of intercropping cocoa with rice and plantain at early stage of field establishment. Four treatments considered were cocoa （sole）, cocoa/rice, cocoa/plantain and cocoa/rice/plantain. Spacing of 3.1 m apart was used for cocoa and plantain while rice was 30 cm. Plot laid out was randomized complete block design replicated three times. Data on cocoa morphological parameters comprising plant height, girth and leaf area as well as weed biomass were measured monthly. Cocoa survival count was also determined. Data collected were subjected to ANOVA, and LSD was used to separate the means. Survival count showed over 95% survival in all treatments without any significance differences. On plant height and leaf area vegetative growth were significantly higher （P 〈 0.05） in the intercrops than the sole cocoa but not significantly different in all the months. Plant vigour was significantly higher in cocoa/plantain intercrop. Cocoa/rice/plantain produced the least weed biomass while cocoa sole gave the highest. Therefore, cocoa/rice and cocoa/plantain intercrops could be recommended to cocoa farmers in Nigeria instead of sole planting at early age of field establishment.
文摘Application of improper methods on rice processing affects rice quality and head rice recovery. In Vietnam, paddy with different moisture contents （from 13% to 17%） is dehusked by both rubber roll and stone disk. Thus, objective of this research was to evaluate the technical and economic aspects of the two methods. Optimization was conducted with 20 experiments for input factors （moisture content） and output factors （head brown rice recovery, specific energy consumption）. Besides, other factors were also monitored, such as the gap between the two disks, speed of disk and roll, and pressure of rubber roll on paddy. Test results showed that the maximum value of head brown rice （77.4%） and the minimum value of specific energy consumption （0.66 kWh/ton） corresponding to moisture content of paddy of 13.7% for stone disk dehusker. At similar moisture content （13.7%）, head brown rice recovery and specific energy consumption were 77.2% and 1.04 kWh/ton for rubber roll dehusker, respectively. As the result, specific energy consumption of rubber roll dehusker was higher than that of stone disk dehusker, corresponding to the higher dehusking efficiency.
基金supported by the National Natural Science Foundation of China(Grant Nos. 40571115 and 40271078)the National Hi-Tech Research and Development Program of China(Grant No. 2006AA10Z203)
文摘Hyperspectral reflectance (350-2500 nm) measurements were made over two experimental rice fields containing two cultivars treated with three levels of nitrogen application.Four different transformations of the reflectance data were analyzed for their capability to predict rice biophysical parameters,comprising leaf area index (LAI;m-2 green leaf area m-2 soil) and green leaf chlorophyll density (GLCD;mg chlorophyll m 2 soil),using stepwise multiple regression (SMR) models and support vector machines (SVMs).Four transformations of the rice canopy data were made,comprising reflectances (R),first-order derivative reflectances (D1),second-order derivative reflectances (D2),and logarithm transformation of reflectances (LOG).The polynomial kernel (POLY) of the SVM using R was the best model to predict rice LAI,with a root mean square error (RMSE) of 1.0496 LAI units.The analysis of variance kernel of SVM using LOG was the best model to predict rice GLCD,with an RMSE of 523.0741 mg m-2.The SVM approach was not only superior to SMR models for predicting the rice biophysical parameters,but also provided a useful exploratory and predictive tool for analyzing different transformations of reflectance data.
