随着大规模可再生能源的开发和应用,电网变得越来越庞大且复杂,如何保证大量不同控制器之间的协调是最值得关注的问题之一。利用微分博弈理论可以解决协同控制的问题。然而,传统算法难以求解带约束的微分博弈问题。此外,现有研究建立的...随着大规模可再生能源的开发和应用,电网变得越来越庞大且复杂,如何保证大量不同控制器之间的协调是最值得关注的问题之一。利用微分博弈理论可以解决协同控制的问题。然而,传统算法难以求解带约束的微分博弈问题。此外,现有研究建立的仿真模型几乎是线性的,不利于实际工程应用。针对上述问题,提出了一种基于加权果蝇优化算法(Weighting Fruit Fly Optimization Algorithm,WFOA)的协同进化算法来求解具有非线性约束的多区域频率协同控制模型。仿真结果表明,与协同进化遗传算法和协同多目标粒子群优化算法相比,该方法具有更好的控制效率,同时对系统出现的外部扰动变化及内部机组参数变动具有很好的鲁棒性。展开更多
An improved model predictive control algorithm is proposed for Hammerstein-Wiener nonlinear systems.The proposed synthesis algorithm contains two parts:offline design the polytopic invariant sets,and online solve the ...An improved model predictive control algorithm is proposed for Hammerstein-Wiener nonlinear systems.The proposed synthesis algorithm contains two parts:offline design the polytopic invariant sets,and online solve the min-max optimization problem.The polytopic invariant set is adopted to replace the traditional ellipsoid invariant set.And the parameter-correlation nonlinear control law is designed to replace the traditional linear control law.Consequently,the terminal region is enlarged and the control effect is improved.Simulation and experiment are used to verify the validity of the wind tunnel flow field control algorithm.展开更多
Objective: To investigate the mitochondrial DNA sequence polymorphism in Chinese Dongxiang ethnic group and to provide basic data used in ethnic origin investigation and forensic purpose. Methods: Genomic DNA was extr...Objective: To investigate the mitochondrial DNA sequence polymorphism in Chinese Dongxiang ethnic group and to provide basic data used in ethnic origin investigation and forensic purpose. Methods: Genomic DNA was extracted from the whole blood of 100 unrelated individuals of Chinese Dongxiang ethnic group by standard Chelex-100 method. The sequence polymorphism was determined by PCR amplification and direct sequencing. Results: Eighty-two polymorphic sites were identified in mtDNA D-loop region 16 091 - 16 418 np, and 88 haplotypes were found. The genetic diversity was calculated to he 0.9969, and the genetic identity was 0.013 2. Conclusion: There are some particular polymorphic sites in Chinese Dongxiang ethnic group, and these sites provide an important basis to investigate the origin of Dongxiang and the relationship between Dongxiang and other ethnic groups. The result also suggested that sequence polymorphism from 16 091 -16 418 np in human mitochondrial DNA control region can be an useful tool for forensic identity.展开更多
Multiple cropping index （MCI） is the ratio of total sown area and cropland area in a region, which represents the regional time intensity of planting crops. Multiple cropping systems have effectively improved the ut...Multiple cropping index （MCI） is the ratio of total sown area and cropland area in a region, which represents the regional time intensity of planting crops. Multiple cropping systems have effectively improved the utilization efficiency and production of cropland by increasing cropping frequency in one year. Meanwhile, it has also significantly altered biogeochemical cycles. Therefore, exploring the spatio-temporal dynamics of multiple cropping intensity is of great significance for ensuring food and ecological security. In this study, MCI of Huang-Huai-Hai agricultural region with intensive cropping practices was extracted based on a cropping intensity mapping algorithm using MODIS Enhanced Vegetation Index （EVI） time series at 500-m spatial resolution and 8-day time intervals. Then the physical characteristics and landscape pattern of MCI trends were analyzed from 2000-2012. Results showed that MCI in Huang-Huai-Hai agricultural region has increased from 152% to 156% in the 12 years. Topography is a primary factor in determining more stable in hilly area than in plain area. An the spatial pattern dynamics of MCI, which is increase from 158% to 164% of MCI occurred irplain area while there was almost no change in hilly area with single cropping. The most active region of MCI change was the intersection zone between the hilly area and plain area. In spatial patterns, landscape of multiple cropping systems tended to be homogenized reflected by a reduction in the degree of fragmentation and an increase in the degree of concentration of cropland with the same cropping system.展开更多
文摘随着大规模可再生能源的开发和应用,电网变得越来越庞大且复杂,如何保证大量不同控制器之间的协调是最值得关注的问题之一。利用微分博弈理论可以解决协同控制的问题。然而,传统算法难以求解带约束的微分博弈问题。此外,现有研究建立的仿真模型几乎是线性的,不利于实际工程应用。针对上述问题,提出了一种基于加权果蝇优化算法(Weighting Fruit Fly Optimization Algorithm,WFOA)的协同进化算法来求解具有非线性约束的多区域频率协同控制模型。仿真结果表明,与协同进化遗传算法和协同多目标粒子群优化算法相比,该方法具有更好的控制效率,同时对系统出现的外部扰动变化及内部机组参数变动具有很好的鲁棒性。
基金Project(61074074)supported by the National Natural Science Foundation,ChinaProject(KT2012C01J0401)supported by the Group Innovation Fund,China
文摘An improved model predictive control algorithm is proposed for Hammerstein-Wiener nonlinear systems.The proposed synthesis algorithm contains two parts:offline design the polytopic invariant sets,and online solve the min-max optimization problem.The polytopic invariant set is adopted to replace the traditional ellipsoid invariant set.And the parameter-correlation nonlinear control law is designed to replace the traditional linear control law.Consequently,the terminal region is enlarged and the control effect is improved.Simulation and experiment are used to verify the validity of the wind tunnel flow field control algorithm.
基金Supported by the National Key Technologies R&D Program in the 9th five-year plan of China (No.96-919-01-04-3)
文摘Objective: To investigate the mitochondrial DNA sequence polymorphism in Chinese Dongxiang ethnic group and to provide basic data used in ethnic origin investigation and forensic purpose. Methods: Genomic DNA was extracted from the whole blood of 100 unrelated individuals of Chinese Dongxiang ethnic group by standard Chelex-100 method. The sequence polymorphism was determined by PCR amplification and direct sequencing. Results: Eighty-two polymorphic sites were identified in mtDNA D-loop region 16 091 - 16 418 np, and 88 haplotypes were found. The genetic diversity was calculated to he 0.9969, and the genetic identity was 0.013 2. Conclusion: There are some particular polymorphic sites in Chinese Dongxiang ethnic group, and these sites provide an important basis to investigate the origin of Dongxiang and the relationship between Dongxiang and other ethnic groups. The result also suggested that sequence polymorphism from 16 091 -16 418 np in human mitochondrial DNA control region can be an useful tool for forensic identity.
基金National Natural Science Foundation of China,No.41430861,No.41471453Strategic Priority Research Program,the Chinese Academy of Sciences(CAS),No.XDA20010202
文摘Multiple cropping index （MCI） is the ratio of total sown area and cropland area in a region, which represents the regional time intensity of planting crops. Multiple cropping systems have effectively improved the utilization efficiency and production of cropland by increasing cropping frequency in one year. Meanwhile, it has also significantly altered biogeochemical cycles. Therefore, exploring the spatio-temporal dynamics of multiple cropping intensity is of great significance for ensuring food and ecological security. In this study, MCI of Huang-Huai-Hai agricultural region with intensive cropping practices was extracted based on a cropping intensity mapping algorithm using MODIS Enhanced Vegetation Index （EVI） time series at 500-m spatial resolution and 8-day time intervals. Then the physical characteristics and landscape pattern of MCI trends were analyzed from 2000-2012. Results showed that MCI in Huang-Huai-Hai agricultural region has increased from 152% to 156% in the 12 years. Topography is a primary factor in determining more stable in hilly area than in plain area. An the spatial pattern dynamics of MCI, which is increase from 158% to 164% of MCI occurred irplain area while there was almost no change in hilly area with single cropping. The most active region of MCI change was the intersection zone between the hilly area and plain area. In spatial patterns, landscape of multiple cropping systems tended to be homogenized reflected by a reduction in the degree of fragmentation and an increase in the degree of concentration of cropland with the same cropping system.
