The local characteristics of multi-dimensional modeling method of multivariate copula. A new modeling remedy this defect. Different types of copula distribution random variables are seldom considered in the general me...The local characteristics of multi-dimensional modeling method of multivariate copula. A new modeling remedy this defect. Different types of copula distribution random variables are seldom considered in the general method, called pair-copula construction, is introduced to functions are allowed to be introduced in this method. Correspondingly, the related characteristics of complex multivariate can be described by a cascade of pair-copula acting on two variables at a time. In the analysis of asynchronism-synchronism of regional precipitation in WED inter- basin water transfer areas, the pair-copula construction method is compared with the general modeling method of mul- tivariate copula. The results show that the local dependence structure would exist among hydrologic variables even in three-dimensional cases. In this situation, the general modeling method of multivariate copula would face difficulties in fitting distribution. However, the pair-copula construction method could capture the local information of hydrologic variables efficiently by introducing different types of copula distribution functions. Moreover, the compensation ca- pacity of water resources is strong in different hydrological areas of WED water transfer project. The asynchronous frequency of wetness and dryness is 69.64% and the favorable frequency for water transfer is 46.15%.展开更多
The paper presents a mathematical model of special construction induction traction motor. On the base of predictive filtering, analytical studies, fuzzy logic control, relying on the virtual data generated by FEM （Fi...The paper presents a mathematical model of special construction induction traction motor. On the base of predictive filtering, analytical studies, fuzzy logic control, relying on the virtual data generated by FEM （Finite Element Method） and BEM （Boundary Element Method） is detected faults of induction motor. Digital predictive filter is used to separate a fundamental harmonic from spectrum current and voltage harmonics. Fuzzy logic control is used to identify a motor state. Magnetic fields distribution in the traction motor, of the wheel vehicle is presented in the paper. Modem diagnostics method has been used for faulty motor simulation and shows results of motor fault effects. Some computer programs were applied in calculation of magnetic fields distribution. On the base of magnetic field distributions were analyzed different failures situations. Some laboratory experiments realized for induction traction motor were verified by results of computer calculations.展开更多
A novel chromatic dispersion(CD) monitoring technique based on asynchronous amplitude sampling(AAS) is proposed for a higher modulation format and higher rate system.The dispersion and other impairment factors can be ...A novel chromatic dispersion(CD) monitoring technique based on asynchronous amplitude sampling(AAS) is proposed for a higher modulation format and higher rate system.The dispersion and other impairment factors can be separated with the definition of monitoring parameter M.A 400 Gbit/s 256 quadrature amplitude modulation(QAM)system is built using Optisystem 13.0 beta software.Simulations of CD monitoring technique for different bandwidths of sampling Gaussian filter,optical signal to noise ratios(OSNRs) and duty cycles are investigated,and the tolerance is also discussed.Simulation results show that the method can be less affected by noise,and a higher accuracy of 600 ps/(nm.km) can be achieved.The technique supports a wide range of data traffic and enhances operation flexibility of optical networks.展开更多
Although the degree of mate competition, given extreme differences in sex ratio, explains much of the pattern of male-biased size dimorphism among diverse taxa, it fails for some species which have potential for inten...Although the degree of mate competition, given extreme differences in sex ratio, explains much of the pattern of male-biased size dimorphism among diverse taxa, it fails for some species which have potential for intense male competition for mates and yet exhibit little or no sexual size dimorphism （SSD）. This fact suggest that species with low SSD should be express the effect of evolutionary pressure in non-obvious geometrical shape promoted by sex ratio in an evolutionary time scale. To evaluate this hypothesis we used phylogenetic comparative method in a Bayesian framework to investigate the evolution of SSD and the role of sex ratio at inter-specific level in the species of Ceroglossus （Coleoptera： Carabidae）. In our results the proportion farthest from 1：1 is associated with more disparate body shape, even though the entire group has minimum variation in sex ratio, which is an intrinsic life history character of this group considering its phylogenetic conservatism or phylogenetic signal. We suggest that the sex ratio has determined the dimorphism degree during evolution of this group, since both traits have increased or decreased together during the species divergence （i.e. positive phylogenetic correlation： r2=0.85）. We suggest that morphological studies of SSD will benefit from using comparative method with Bayesian approaches to assess the effect of phylogenetic history and its uncertainty. Finally, this will be allow to researchers to quantify the uncertainty of specific evolutionary hypotheses accounting for observed sexual dimorphism patterns.展开更多
基金Supported by National Natural Science Foundation of China (No. 50979011)
文摘The local characteristics of multi-dimensional modeling method of multivariate copula. A new modeling remedy this defect. Different types of copula distribution random variables are seldom considered in the general method, called pair-copula construction, is introduced to functions are allowed to be introduced in this method. Correspondingly, the related characteristics of complex multivariate can be described by a cascade of pair-copula acting on two variables at a time. In the analysis of asynchronism-synchronism of regional precipitation in WED inter- basin water transfer areas, the pair-copula construction method is compared with the general modeling method of mul- tivariate copula. The results show that the local dependence structure would exist among hydrologic variables even in three-dimensional cases. In this situation, the general modeling method of multivariate copula would face difficulties in fitting distribution. However, the pair-copula construction method could capture the local information of hydrologic variables efficiently by introducing different types of copula distribution functions. Moreover, the compensation ca- pacity of water resources is strong in different hydrological areas of WED water transfer project. The asynchronous frequency of wetness and dryness is 69.64% and the favorable frequency for water transfer is 46.15%.
文摘The paper presents a mathematical model of special construction induction traction motor. On the base of predictive filtering, analytical studies, fuzzy logic control, relying on the virtual data generated by FEM （Finite Element Method） and BEM （Boundary Element Method） is detected faults of induction motor. Digital predictive filter is used to separate a fundamental harmonic from spectrum current and voltage harmonics. Fuzzy logic control is used to identify a motor state. Magnetic fields distribution in the traction motor, of the wheel vehicle is presented in the paper. Modem diagnostics method has been used for faulty motor simulation and shows results of motor fault effects. Some computer programs were applied in calculation of magnetic fields distribution. On the base of magnetic field distributions were analyzed different failures situations. Some laboratory experiments realized for induction traction motor were verified by results of computer calculations.
基金supported by the National Natural Science Foundation of China(No.61274121)the Natural Science Foundation of Jiangsu Province(No.BK2012829)the Scientific Research Foundation of Nanjing University of Posts and Telecommunications(No.NY212007)
文摘A novel chromatic dispersion(CD) monitoring technique based on asynchronous amplitude sampling(AAS) is proposed for a higher modulation format and higher rate system.The dispersion and other impairment factors can be separated with the definition of monitoring parameter M.A 400 Gbit/s 256 quadrature amplitude modulation(QAM)system is built using Optisystem 13.0 beta software.Simulations of CD monitoring technique for different bandwidths of sampling Gaussian filter,optical signal to noise ratios(OSNRs) and duty cycles are investigated,and the tolerance is also discussed.Simulation results show that the method can be less affected by noise,and a higher accuracy of 600 ps/(nm.km) can be achieved.The technique supports a wide range of data traffic and enhances operation flexibility of optical networks.
文摘Although the degree of mate competition, given extreme differences in sex ratio, explains much of the pattern of male-biased size dimorphism among diverse taxa, it fails for some species which have potential for intense male competition for mates and yet exhibit little or no sexual size dimorphism （SSD）. This fact suggest that species with low SSD should be express the effect of evolutionary pressure in non-obvious geometrical shape promoted by sex ratio in an evolutionary time scale. To evaluate this hypothesis we used phylogenetic comparative method in a Bayesian framework to investigate the evolution of SSD and the role of sex ratio at inter-specific level in the species of Ceroglossus （Coleoptera： Carabidae）. In our results the proportion farthest from 1：1 is associated with more disparate body shape, even though the entire group has minimum variation in sex ratio, which is an intrinsic life history character of this group considering its phylogenetic conservatism or phylogenetic signal. We suggest that the sex ratio has determined the dimorphism degree during evolution of this group, since both traits have increased or decreased together during the species divergence （i.e. positive phylogenetic correlation： r2=0.85）. We suggest that morphological studies of SSD will benefit from using comparative method with Bayesian approaches to assess the effect of phylogenetic history and its uncertainty. Finally, this will be allow to researchers to quantify the uncertainty of specific evolutionary hypotheses accounting for observed sexual dimorphism patterns.
