为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable conv...为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable convolution, DepthSepConv)结构,减少模型参数量,提升模型检测性能;其次,在颈部网络部分添加全局注意力机制(global attention mechanism, GAM)模块,强化特征中语义信息和位置信息,提高模型特征融合能力;然后,引入轻量级通用上采样内容感知重组(content-aware reassembly of features,CARAFE)模块,提高模型对重要特征的提取能力;最后,使用Wise-IoU(weighted interpolation of sequential evidence for intersection over union)边界损失函数代替原损失函数,提升网络边界框回归性能和对小目标病害的检测效果。试验结果表明,对于大田环境下所采集的小麦病害数据集,改进后模型的参数量及模型大小相比原YOLOv8n基线模型分别降低了12.5%和11.3%,同时精确度(precision)及平均精度均值(mean average precision,m AP)相较于原模型分别提高了4.5和1.9个百分点,优于其他对比目标检测算法,可为小麦病害检测无人机等移动端检测装备的部署和应用提供参考。展开更多
A thrust estimator with high precision and excellent real-time performance is needed to mitigate perfor- mance deterioration for future aero-engines. A weight least squares support vector regression is proposed using ...A thrust estimator with high precision and excellent real-time performance is needed to mitigate perfor- mance deterioration for future aero-engines. A weight least squares support vector regression is proposed using a novel weighting strategy. Then a thrust estimator based on the proposed regression is designed for the perfor- mance deterioration. Compared with the existing weighting strategy, the novel one not only satisfies the require- ment of precision but also enhances the real-time performance. Finally, numerical experiments demonstrate the effectiveness and feasibility of the proposed weighted least squares support vector regression for thrust estimator. Key words ： intelligent engine control; least squares ; support vector machine ; performance deterioration展开更多
[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the secon...[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the second last leaf （L2）,removing upper part of spike （L3） and controlling （CK） were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat＇s 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat＇s 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat.展开更多
As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural...As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.展开更多
Wheat germ meal is the by production of oil extracting, and a great quantity of it has been wasted, thus the quantity of lost protein is great. In order to use wheat germ meal proteins adequately, wheat germ proteins ...Wheat germ meal is the by production of oil extracting, and a great quantity of it has been wasted, thus the quantity of lost protein is great. In order to use wheat germ meal proteins adequately, wheat germ proteins were hydrolyzed to anti-oxidation peptides by using alkaline protease. Through the single factor analysis and regression analysis, the optimized experiment conditions of hydrolysising wheat germ meal to wheat germ peptides were enzymatic quantity 0.8%（w/w）, material to liquid ratio 1∶12.3, enzymolysis time 2.1 h. Under these conditions, the scavenging effect was 49.78%,the DH was 22% and peptides content in enzymatic hydrolysate was 1.9%（w/w）.By SDS-PAGE electrophoresis,the molecular weight range of wheat germ peptides were below 10 ku and most were between 4.54 and 5.63 ku.The wheat germ proteins could be used ful y and grain resources would be saved.展开更多
Based on the infinitesimal and one parameter transformation, the problem of Lie symmetry of three-order Lagrangian equations has been studied. Under Lie transformation, the sufficient and necessary condition which kee...Based on the infinitesimal and one parameter transformation, the problem of Lie symmetry of three-order Lagrangian equations has been studied. Under Lie transformation, the sufficient and necessary condition which keeps three-order Lagrangian equations to be unchanged and the invariant are obtained in this paper.展开更多
Rifapentine, an important antibiotic, was crystallized from methanol solvent in the form of its methanol solvate. The crystal structure of rifapentine methanol solvate belongs to monoclinic, space group P21, with the ...Rifapentine, an important antibiotic, was crystallized from methanol solvent in the form of its methanol solvate. The crystal structure of rifapentine methanol solvate belongs to monoclinic, space group P21, with the unit cell parameters of a = 1.2278（3） nm, b = 1.9768（4） rim, c = 1.2473（3） nm, Z= 2, and β = 112.35（3）. The parallelepiped.morphology was also predicted by Materials Studio simulation program.. The influence of intermolecular in-teraction was taken into account in the attachment energy model. The crystal shape fits the calculated morphology well, which was performed on the potential energy minimized model using a generic DREIDING 2.21 force fieldand developed minimization protocol with derived＇partial charges.展开更多
For the cooperative multi-cell systems with muki-user MIMO, a new limited feedback bit allocation scheme is proposed to minimize the rate loss caused by quantization error. In the proposed scheme, the Channel State In...For the cooperative multi-cell systems with muki-user MIMO, a new limited feedback bit allocation scheme is proposed to minimize the rate loss caused by quantization error. In the proposed scheme, the Channel State Information （CSI） feedback of cell-edge user for the local service cell and the adjacent interference cell are separately quantized. Based on the upper bound of the rate loss of cell-edge user due to the limited feedback, the number of feedback bits for quantized CSI of the local service cell and the adjacent cell are optimized with the fixed total bits of the limited feedback. The simulation shows that our proposed scheme of feedback bits allocation efficiently decreases the interference and increases the rate of systems compared with that of equal bits allocation and those of other allocations.展开更多
Extension of a B-spline curve or surface is a useful function in a CAD system. This paper presents an algorithm for extending cubic B-spline curves or surfaces to one or more target points. To keep the extension curve...Extension of a B-spline curve or surface is a useful function in a CAD system. This paper presents an algorithm for extending cubic B-spline curves or surfaces to one or more target points. To keep the extension curve segment GC^2-continuous with the original one, a family of cubic polynomial interpolation curves can be constructed. One curve is chosen as the solution from a sub-class of such a family by setting one GC^2 parameter to be zero and determining the second GC^2 parameter by minimizing the strain energy. To simplify the final curve representation, the extension segment is reparameterized to achieve C-continuity with the given B-spline curve, and then knot removal from the curve is done. As a result, a sub-optimized solution subject to the given constraints and criteria is obtained. Additionally, new control points of the extension B-spline segment can be determined by solving lower triangular linear equations. Some computing examples for comparing our method and other methods are given.展开更多
文摘为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable convolution, DepthSepConv)结构,减少模型参数量,提升模型检测性能;其次,在颈部网络部分添加全局注意力机制(global attention mechanism, GAM)模块,强化特征中语义信息和位置信息,提高模型特征融合能力;然后,引入轻量级通用上采样内容感知重组(content-aware reassembly of features,CARAFE)模块,提高模型对重要特征的提取能力;最后,使用Wise-IoU(weighted interpolation of sequential evidence for intersection over union)边界损失函数代替原损失函数,提升网络边界框回归性能和对小目标病害的检测效果。试验结果表明,对于大田环境下所采集的小麦病害数据集,改进后模型的参数量及模型大小相比原YOLOv8n基线模型分别降低了12.5%和11.3%,同时精确度(precision)及平均精度均值(mean average precision,m AP)相较于原模型分别提高了4.5和1.9个百分点,优于其他对比目标检测算法,可为小麦病害检测无人机等移动端检测装备的部署和应用提供参考。
基金Supported by the National Natural Science Foundation of China(51006052)the Nanjing University of Science and Technology Outstanding Scholar Supporting Program~~
文摘A thrust estimator with high precision and excellent real-time performance is needed to mitigate perfor- mance deterioration for future aero-engines. A weight least squares support vector regression is proposed using a novel weighting strategy. Then a thrust estimator based on the proposed regression is designed for the perfor- mance deterioration. Compared with the existing weighting strategy, the novel one not only satisfies the require- ment of precision but also enhances the real-time performance. Finally, numerical experiments demonstrate the effectiveness and feasibility of the proposed weighted least squares support vector regression for thrust estimator. Key words ： intelligent engine control; least squares ; support vector machine ; performance deterioration
基金Supported by Jiangsu High School Natural Science Fund(09KJB210004)Undergraduate Practice Innovation Project of Nanjing University of Information Science & Technology (09CX0025 )Educational Reform Project of Nanjing University of Information Science &Technology (09JY0036)~~
文摘[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the second last leaf （L2）,removing upper part of spike （L3） and controlling （CK） were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat＇s 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat＇s 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat.
文摘As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.
文摘Wheat germ meal is the by production of oil extracting, and a great quantity of it has been wasted, thus the quantity of lost protein is great. In order to use wheat germ meal proteins adequately, wheat germ proteins were hydrolyzed to anti-oxidation peptides by using alkaline protease. Through the single factor analysis and regression analysis, the optimized experiment conditions of hydrolysising wheat germ meal to wheat germ peptides were enzymatic quantity 0.8%（w/w）, material to liquid ratio 1∶12.3, enzymolysis time 2.1 h. Under these conditions, the scavenging effect was 49.78%,the DH was 22% and peptides content in enzymatic hydrolysate was 1.9%（w/w）.By SDS-PAGE electrophoresis,the molecular weight range of wheat germ peptides were below 10 ku and most were between 4.54 and 5.63 ku.The wheat germ proteins could be used ful y and grain resources would be saved.
文摘Based on the infinitesimal and one parameter transformation, the problem of Lie symmetry of three-order Lagrangian equations has been studied. Under Lie transformation, the sufficient and necessary condition which keeps three-order Lagrangian equations to be unchanged and the invariant are obtained in this paper.
基金Supported by Open Fund of Mineral Resources Chemistry Key Laboratory of Scihuan Higher Education Institutions
文摘Rifapentine, an important antibiotic, was crystallized from methanol solvent in the form of its methanol solvate. The crystal structure of rifapentine methanol solvate belongs to monoclinic, space group P21, with the unit cell parameters of a = 1.2278（3） nm, b = 1.9768（4） rim, c = 1.2473（3） nm, Z= 2, and β = 112.35（3）. The parallelepiped.morphology was also predicted by Materials Studio simulation program.. The influence of intermolecular in-teraction was taken into account in the attachment energy model. The crystal shape fits the calculated morphology well, which was performed on the potential energy minimized model using a generic DREIDING 2.21 force fieldand developed minimization protocol with derived＇partial charges.
基金Acknowledgements The authors would like to thank the reviewers for their detailed reviews and constructive comments, which have helped to improve the quality of this paper. This work was supported partiaUy by the National Natural Science Foundation of China under Grant No. 60772110 Fundamental Research Funds for the Central Universities.
文摘For the cooperative multi-cell systems with muki-user MIMO, a new limited feedback bit allocation scheme is proposed to minimize the rate loss caused by quantization error. In the proposed scheme, the Channel State Information （CSI） feedback of cell-edge user for the local service cell and the adjacent interference cell are separately quantized. Based on the upper bound of the rate loss of cell-edge user due to the limited feedback, the number of feedback bits for quantized CSI of the local service cell and the adjacent cell are optimized with the fixed total bits of the limited feedback. The simulation shows that our proposed scheme of feedback bits allocation efficiently decreases the interference and increases the rate of systems compared with that of equal bits allocation and those of other allocations.
文摘Extension of a B-spline curve or surface is a useful function in a CAD system. This paper presents an algorithm for extending cubic B-spline curves or surfaces to one or more target points. To keep the extension curve segment GC^2-continuous with the original one, a family of cubic polynomial interpolation curves can be constructed. One curve is chosen as the solution from a sub-class of such a family by setting one GC^2 parameter to be zero and determining the second GC^2 parameter by minimizing the strain energy. To simplify the final curve representation, the extension segment is reparameterized to achieve C-continuity with the given B-spline curve, and then knot removal from the curve is done. As a result, a sub-optimized solution subject to the given constraints and criteria is obtained. Additionally, new control points of the extension B-spline segment can be determined by solving lower triangular linear equations. Some computing examples for comparing our method and other methods are given.
