Let X be a Banach space, S(X) be the unit sphere of X, φ be a function: S(X)→ S(X *) such that φ(x)∈ x, and v φ(ε) =inf 1-12x+y: x,y∈S(X), and 〈φ(x), x-y 〉≥ε, 0≤ε≤2, whe...Let X be a Banach space, S(X) be the unit sphere of X, φ be a function: S(X)→ S(X *) such that φ(x)∈ x, and v φ(ε) =inf 1-12x+y: x,y∈S(X), and 〈φ(x), x-y 〉≥ε, 0≤ε≤2, where x is the set of norm 1 supporting functionals of S(X) at x. A geometric concept, modulus of V convexity V(ε)= sup {V φ(ε), for all φ: S(X)→S(X *)}, is introduced; the properties of V(ε) and the relationship between V(ε) and other geometric concepts are discussed. The main result is that V12>0 implies normal structure.展开更多
Due to rapid growth in wireless communication technology,higher bandwidth requirement for advance telecommunication systems,capable of operating on two or higher bands with higher channel capacities and minimum distor...Due to rapid growth in wireless communication technology,higher bandwidth requirement for advance telecommunication systems,capable of operating on two or higher bands with higher channel capacities and minimum distortion losses is desired.In this paper,a compact Ultra-Wideband(UWB)V-shaped monopole antenna is presented.UWB response is achieved by modifying the ground plane with Chichen Itzia inspired rectangular staircase shape.The proposed V-shaped is designed by incorporating a rectangle,and an inverted isosceles triangle using FR4 substrate.The size of the antenna is 25 mm×26 mm×1.6 mm.The proposed V-shaped monopole antenna produces bandwidth response of 3 GHz Industrial,Scientific,and Medical(ISM),Worldwide Interoperability for Microwave Access(WiMAX),(IEEE 802.11/HIPERLAN band,5G sub 6 GHz)which with an additional square cut amplified the bandwidth response up to 8 GHz ranging from 3.1 GHz to 10.6 GHz attaining UWB defined by Federal Communications Commission(FCC)with a maximum gain of 3.83 dB.The antenna is designed in Ansys HFSS.Results for key performance parameters of the antenna are presented.The measured results are in good agreement with the simulated results.Due to flat gain,uniform group delay,omni directional radiation pattern characteristics and well-matched impedance,the proposed antenna is suitable for WiMAX,ISM and heterogeneous wireless systems.展开更多
The electronic structures of pure V, Nb and Ta metals with bcc structure were determined by one atom (OA) theory. According to the electronic structures of these metals, their potential curves, cohesive energies, latt...The electronic structures of pure V, Nb and Ta metals with bcc structure were determined by one atom (OA) theory. According to the electronic structures of these metals, their potential curves, cohesive energies, lattice parameters, elasticity and the dependence of linear thermal expansion coefficients on temperature were calculated. The electronic structures and characteristic properties of these metals with fcc and hcp structures and liquid states were studied.展开更多
基于密度泛函理论,采用第一性原理计算方法研究了C,N,O原子在金属V中的扩散行为.首先,讨论了C,N,O原子在V体心立方晶格中的间隙占位情况,分析了其在间隙位置与V晶格的相互作用,并探究了这种相互作用对金属V电子结构的影响.研究结果表明:...基于密度泛函理论,采用第一性原理计算方法研究了C,N,O原子在金属V中的扩散行为.首先,讨论了C,N,O原子在V体心立方晶格中的间隙占位情况,分析了其在间隙位置与V晶格的相互作用,并探究了这种相互作用对金属V电子结构的影响.研究结果表明:C,N,O原子在V的八面体间隙位置更为稳定,并且C,N,O原子的2p电子与V的3d电子之间有比较强的成键作用;C,N,O原子的扩散势垒分别为0.89,1.26,0.98 e V,并得出了其扩散系数表达式;最后,通过阿仑尼乌斯关系图对比了三者在V中扩散系数的大小,并计算出体系温度在500—1100 K之间时其在V中的扩散系数,计算结果与实验值基本符合.展开更多
贝叶斯网络由于其强大的不确定性推理能力和因果可表示性越来越受到研究者的关注。从数据中学习一个贝叶斯网络结构被称为NP-hard问题。其中,针对K2算法强依赖于变量拓扑序的问题,提出了一种组合变量邻居集和v-结构信息的K2改进学习方法...贝叶斯网络由于其强大的不确定性推理能力和因果可表示性越来越受到研究者的关注。从数据中学习一个贝叶斯网络结构被称为NP-hard问题。其中,针对K2算法强依赖于变量拓扑序的问题,提出了一种组合变量邻居集和v-结构信息的K2改进学习方法TSK2(Two-Step Search Strategy of K2)。该方法有效减小了序空间搜索规模,同时避免了过早陷入局部最优。具体而言,该方法在约束算法定向规则的启示下,借助识别的v-结构和邻居集信息可靠调整汇点的邻居在序中的位置;其次,在贝网基本组成结构的启发下,借助变量邻居集信息,通过执行顺连、分连、汇连3个基本结构的搜索,准确修正父节点与子节点的序位置,获得最优序列。实验结果表明,在Asia和Alarm网络数据集上,与对比方法相比,所提算法的准确率得到显著提升,可以获得更准确的网络结构。展开更多
文摘Let X be a Banach space, S(X) be the unit sphere of X, φ be a function: S(X)→ S(X *) such that φ(x)∈ x, and v φ(ε) =inf 1-12x+y: x,y∈S(X), and 〈φ(x), x-y 〉≥ε, 0≤ε≤2, where x is the set of norm 1 supporting functionals of S(X) at x. A geometric concept, modulus of V convexity V(ε)= sup {V φ(ε), for all φ: S(X)→S(X *)}, is introduced; the properties of V(ε) and the relationship between V(ε) and other geometric concepts are discussed. The main result is that V12>0 implies normal structure.
基金This work was supported by the Research Program through the National Research Foundation of Korea,NRF-2019R1A2C1005920,S.K.
文摘Due to rapid growth in wireless communication technology,higher bandwidth requirement for advance telecommunication systems,capable of operating on two or higher bands with higher channel capacities and minimum distortion losses is desired.In this paper,a compact Ultra-Wideband(UWB)V-shaped monopole antenna is presented.UWB response is achieved by modifying the ground plane with Chichen Itzia inspired rectangular staircase shape.The proposed V-shaped is designed by incorporating a rectangle,and an inverted isosceles triangle using FR4 substrate.The size of the antenna is 25 mm×26 mm×1.6 mm.The proposed V-shaped monopole antenna produces bandwidth response of 3 GHz Industrial,Scientific,and Medical(ISM),Worldwide Interoperability for Microwave Access(WiMAX),(IEEE 802.11/HIPERLAN band,5G sub 6 GHz)which with an additional square cut amplified the bandwidth response up to 8 GHz ranging from 3.1 GHz to 10.6 GHz attaining UWB defined by Federal Communications Commission(FCC)with a maximum gain of 3.83 dB.The antenna is designed in Ansys HFSS.Results for key performance parameters of the antenna are presented.The measured results are in good agreement with the simulated results.Due to flat gain,uniform group delay,omni directional radiation pattern characteristics and well-matched impedance,the proposed antenna is suitable for WiMAX,ISM and heterogeneous wireless systems.
文摘The electronic structures of pure V, Nb and Ta metals with bcc structure were determined by one atom (OA) theory. According to the electronic structures of these metals, their potential curves, cohesive energies, lattice parameters, elasticity and the dependence of linear thermal expansion coefficients on temperature were calculated. The electronic structures and characteristic properties of these metals with fcc and hcp structures and liquid states were studied.
文摘基于密度泛函理论,采用第一性原理计算方法研究了C,N,O原子在金属V中的扩散行为.首先,讨论了C,N,O原子在V体心立方晶格中的间隙占位情况,分析了其在间隙位置与V晶格的相互作用,并探究了这种相互作用对金属V电子结构的影响.研究结果表明:C,N,O原子在V的八面体间隙位置更为稳定,并且C,N,O原子的2p电子与V的3d电子之间有比较强的成键作用;C,N,O原子的扩散势垒分别为0.89,1.26,0.98 e V,并得出了其扩散系数表达式;最后,通过阿仑尼乌斯关系图对比了三者在V中扩散系数的大小,并计算出体系温度在500—1100 K之间时其在V中的扩散系数,计算结果与实验值基本符合.
文摘贝叶斯网络由于其强大的不确定性推理能力和因果可表示性越来越受到研究者的关注。从数据中学习一个贝叶斯网络结构被称为NP-hard问题。其中,针对K2算法强依赖于变量拓扑序的问题,提出了一种组合变量邻居集和v-结构信息的K2改进学习方法TSK2(Two-Step Search Strategy of K2)。该方法有效减小了序空间搜索规模,同时避免了过早陷入局部最优。具体而言,该方法在约束算法定向规则的启示下,借助识别的v-结构和邻居集信息可靠调整汇点的邻居在序中的位置;其次,在贝网基本组成结构的启发下,借助变量邻居集信息,通过执行顺连、分连、汇连3个基本结构的搜索,准确修正父节点与子节点的序位置,获得最优序列。实验结果表明,在Asia和Alarm网络数据集上,与对比方法相比,所提算法的准确率得到显著提升,可以获得更准确的网络结构。
