高精度且鲁棒的预测模型建立高度依赖于样本数据的大小、多样性和分布;日益积累的文献数据为获得大量的多样性样本数据提供了可能。以SLM-ed IN 718合金的相对密度(RD)为研究对象,针对从文献中挖掘的激光功率P、扫描速度V、扫描间距HS...高精度且鲁棒的预测模型建立高度依赖于样本数据的大小、多样性和分布;日益积累的文献数据为获得大量的多样性样本数据提供了可能。以SLM-ed IN 718合金的相对密度(RD)为研究对象,针对从文献中挖掘的激光功率P、扫描速度V、扫描间距HS和铺粉厚度LT与RD样本数据存在缺失参数和分布不均问题,采用最大期望化(EM)算法对缺失参数进行补齐;采用带有梯度惩罚的WGAN算法(WGAN-GP)对数据稀疏的低RD区间生成虚拟样本数据。然后,分别基于补齐文献数据和补充虚拟数据,采用常青藤算法优化的随机森林(IVYA-RF)构建了RD预测模型,并对模型预测精度进行了定量评估和实验验证。结果表明:基于补充虚拟数据集构建的IVYA-RF模型II比基于补齐文献数据集构建的IVYA-RF模型I具有更好的预测精度,其原因主要来源于在低RD区间生成虚拟数据后,使建模样本数据的分布均匀性得到改善,这也是数据增强与机器学习相结合的意义所在。对新实验数据的验证取得了满意的预测精度,其中,IVYA-RF模型I验证结果的统计学参数R2(决定系数)、RMSE(均方根误差)、MAE(平均绝对误差)和MRE(平均相对误差)分别达到了0.891、1.352%、0.915%和0.98%;IVYA-RF模型II验证结果的R2增大至0.956,RMSE、MAE和MRE分别减小至0.833%、0.687%和0.71%,同样显示出后者比前者具有更好的预测精度。实验验证结果表明,所构建的RD预测模型具有较好的鲁棒性,从而具备了较好的工程应用价值。展开更多
The economic dispatch problem(EDP) of microgrids operating in both grid-connected and isolated modes within an energy internet framework is addressed in this paper. The multi-agent leader-following consensus algorithm...The economic dispatch problem(EDP) of microgrids operating in both grid-connected and isolated modes within an energy internet framework is addressed in this paper. The multi-agent leader-following consensus algorithm is employed to address the EDP of microgrids in grid-connected mode, while the push-pull algorithm with a fixed step size is introduced for the isolated mode. The proposed algorithm of isolated mode is proven to converge to the optimum when the interaction digraph of microgrids is strongly connected. A unified algorithmic framework is proposed to handle the two modes of operation of microgrids simultaneously, enabling our algorithm to achieve optimal power allocation and maintain the balance between power supply and demand in any mode and any mode switching. Due to the push-pull structure of the algorithm and the use of fixed step size,the proposed algorithm can better handle the case of unbalanced graphs, and the convergence speed is improved. It is documented that when the transmission topology is strongly connected and there is bi-directional communication between the energy router and its neighbors, the proposed algorithm in composite mode achieves economic dispatch even with arbitrary mode switching.Finally, we demonstrate the effectiveness and superiority of our algorithm through numerical simulations.展开更多
Sepsis management has significantly improved over the past decades,with intensivists playing a pivotal role in its identification and treatment.[1,2]However,resource constraints in large tertiary hospitals in China li...Sepsis management has significantly improved over the past decades,with intensivists playing a pivotal role in its identification and treatment.[1,2]However,resource constraints in large tertiary hospitals in China limit patient admissions,leading to overcrowding in the emergency departments(EDs)with critically ill patients.[3]This highlights the urgent need for enhanced risk stratification and optimized sepsis management in emergency settings.展开更多
By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering met...By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering method in pure argon and pure oxygen gas,respectively.The crystal structure,morphological characteristics,composition and optical properties of the obtained films were compared by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ultraviolet(UV)-visible spectrophotometer.The properties of the thin films deposited in different sputtering gases are quite different.For the films deposited in pure argon gas,it is a polycrystalline thin film with(200)preferred orientation,while the film deposited in pure oxygen has no preferred orientation.The grain size,molar ratio of Mg to Ni atoms and optical bandgap are larger for the films deposited in pure argon gas than those deposited in oxygen gas.展开更多
By using a certain hybrid-type convolution operator,we first introduce a new subclass of normalized analytic functions in the open unit disk.For members of this analytic function class,we then derive several propertie...By using a certain hybrid-type convolution operator,we first introduce a new subclass of normalized analytic functions in the open unit disk.For members of this analytic function class,we then derive several properties and characteristics including(for example)the modified Hadamard products,Holder's inequalities and convolution properties as well as some closure properties under a general family of integral transforms.展开更多
文摘高精度且鲁棒的预测模型建立高度依赖于样本数据的大小、多样性和分布;日益积累的文献数据为获得大量的多样性样本数据提供了可能。以SLM-ed IN 718合金的相对密度(RD)为研究对象,针对从文献中挖掘的激光功率P、扫描速度V、扫描间距HS和铺粉厚度LT与RD样本数据存在缺失参数和分布不均问题,采用最大期望化(EM)算法对缺失参数进行补齐;采用带有梯度惩罚的WGAN算法(WGAN-GP)对数据稀疏的低RD区间生成虚拟样本数据。然后,分别基于补齐文献数据和补充虚拟数据,采用常青藤算法优化的随机森林(IVYA-RF)构建了RD预测模型,并对模型预测精度进行了定量评估和实验验证。结果表明:基于补充虚拟数据集构建的IVYA-RF模型II比基于补齐文献数据集构建的IVYA-RF模型I具有更好的预测精度,其原因主要来源于在低RD区间生成虚拟数据后,使建模样本数据的分布均匀性得到改善,这也是数据增强与机器学习相结合的意义所在。对新实验数据的验证取得了满意的预测精度,其中,IVYA-RF模型I验证结果的统计学参数R2(决定系数)、RMSE(均方根误差)、MAE(平均绝对误差)和MRE(平均相对误差)分别达到了0.891、1.352%、0.915%和0.98%;IVYA-RF模型II验证结果的R2增大至0.956,RMSE、MAE和MRE分别减小至0.833%、0.687%和0.71%,同样显示出后者比前者具有更好的预测精度。实验验证结果表明,所构建的RD预测模型具有较好的鲁棒性,从而具备了较好的工程应用价值。
基金supported by the National Natural Science Foundation of China(62103203)
文摘The economic dispatch problem(EDP) of microgrids operating in both grid-connected and isolated modes within an energy internet framework is addressed in this paper. The multi-agent leader-following consensus algorithm is employed to address the EDP of microgrids in grid-connected mode, while the push-pull algorithm with a fixed step size is introduced for the isolated mode. The proposed algorithm of isolated mode is proven to converge to the optimum when the interaction digraph of microgrids is strongly connected. A unified algorithmic framework is proposed to handle the two modes of operation of microgrids simultaneously, enabling our algorithm to achieve optimal power allocation and maintain the balance between power supply and demand in any mode and any mode switching. Due to the push-pull structure of the algorithm and the use of fixed step size,the proposed algorithm can better handle the case of unbalanced graphs, and the convergence speed is improved. It is documented that when the transmission topology is strongly connected and there is bi-directional communication between the energy router and its neighbors, the proposed algorithm in composite mode achieves economic dispatch even with arbitrary mode switching.Finally, we demonstrate the effectiveness and superiority of our algorithm through numerical simulations.
基金supported by grants from the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2021-I2M-1-062,to BD).
文摘Sepsis management has significantly improved over the past decades,with intensivists playing a pivotal role in its identification and treatment.[1,2]However,resource constraints in large tertiary hospitals in China limit patient admissions,leading to overcrowding in the emergency departments(EDs)with critically ill patients.[3]This highlights the urgent need for enhanced risk stratification and optimized sepsis management in emergency settings.
基金supported by the Jilin Provincial Scientific and Technological Development Program(No.20220101036JC)。
文摘By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering method in pure argon and pure oxygen gas,respectively.The crystal structure,morphological characteristics,composition and optical properties of the obtained films were compared by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ultraviolet(UV)-visible spectrophotometer.The properties of the thin films deposited in different sputtering gases are quite different.For the films deposited in pure argon gas,it is a polycrystalline thin film with(200)preferred orientation,while the film deposited in pure oxygen has no preferred orientation.The grain size,molar ratio of Mg to Ni atoms and optical bandgap are larger for the films deposited in pure argon gas than those deposited in oxygen gas.
文摘By using a certain hybrid-type convolution operator,we first introduce a new subclass of normalized analytic functions in the open unit disk.For members of this analytic function class,we then derive several properties and characteristics including(for example)the modified Hadamard products,Holder's inequalities and convolution properties as well as some closure properties under a general family of integral transforms.
