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寿命分布类的次序统计量的联合分布 被引量:6
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作者 王建蓉 《青海师范大学学报(自然科学版)》 2002年第3期26-29,共4页
本文把计算次序统计量的联合分布由两个次序统计量的情况推广到K个次序统计量的情况 ,并求出了一些常用的寿命分布类的k个次序统计量的联合分布。
关键词 次序统计量 联合分布 寿命分布 自分布函数 密度函数 指数分布 Weuibull分布
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Robust user equilibrium model based on cumulative prospect theory under distribution-free travel time 被引量:3
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作者 王伟 孙会君 吴建军 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期761-770,共10页
The assumption widely used in the user equilibrium model for stochastic network was that the probability distributions of the travel time were known explicitly by travelers. However, this distribution may be unavailab... The assumption widely used in the user equilibrium model for stochastic network was that the probability distributions of the travel time were known explicitly by travelers. However, this distribution may be unavailable in reality. By relaxing the restrictive assumption, a robust user equilibrium model based on cumulative prospect theory under distribution-free travel time was presented. In the absence of the cumulative distribution function of the travel time, the exact cumulative prospect value(CPV) for each route cannot be obtained. However, the upper and lower bounds on the CPV can be calculated by probability inequalities.Travelers were assumed to choose the routes with the best worst-case CPVs. The proposed model was formulated as a variational inequality problem and solved via a heuristic solution algorithm. A numerical example was also provided to illustrate the application of the proposed model and the efficiency of the solution algorithm. 展开更多
关键词 user equilibrium cumulative prospect theory distribution-free travel time variational inequality
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Quadratic Radical Function Better Than Fisher z Transformation 被引量:2
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作者 杨正瓴 段志峰 +3 位作者 王晶晶 王腾 宋延文 张军 《Transactions of Tianjin University》 EI CAS 2013年第5期381-384,共4页
A new explicit quadratic radical function is found by numerical experiments,which is simpler and has only 70.778%of the maximal distance error compared with the Fisher z transformation.Furthermore,a piecewise function... A new explicit quadratic radical function is found by numerical experiments,which is simpler and has only 70.778%of the maximal distance error compared with the Fisher z transformation.Furthermore,a piecewise function is constructed for the standard normal distribution:if the independent variable falls in the interval(-1.519,1.519),the proposed function is employed;otherwise,the Fisher z transformation is used.Compared with the Fisher z transformation,this piecewise function has only 38.206%of the total error.The new function is more exact to estimate the confidence intervals of Pearson product moment correlation coefficient and Dickinson best weights for the linear combination of forecasts. 展开更多
关键词 normal distribution cumulative distribution function error function confidence interval correlation coefficient combination of forecasts
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IDFT Numerical Simulation Method for Gaussian Rough Surface with Relatively Large Correlation Length
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作者 王廷剑 王黎钦 赵小力 《Transactions of Tianjin University》 EI CAS 2015年第3期216-222,共7页
A numerical simulation method based on inverse discrete Fourier transform(IDFT)is presented for generating Gaussian rough surface with a desired autocorrelation function(ACF). The probability density function of the h... A numerical simulation method based on inverse discrete Fourier transform(IDFT)is presented for generating Gaussian rough surface with a desired autocorrelation function(ACF). The probability density function of the height distribution of the generated Gaussian surface and the root-mean-square height of the rough surface are also considered. It is found that the height distribution of the generated surface follows the Gaussian distribution, the deviation of the root-mean-square height of the modeled rough surface from the desired value is smaller than that of Patir's method, and the autocorrelation function of the modeled surface is also in good agreement with the desired autocorrelation function. Compared with Patir's method, the modeled surface generated by the IDFT method is in better agreement with the desired autocorrelation function, especially when the correlation length is relatively large. 展开更多
关键词 numerical simulation Gaussian rough surface autocorrelation function root-mean-square height IDFT
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Spinor Boltzmann Equation with Two Momenta at the Fermi Level
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作者 王正川 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第12期909-914,共6页
Based on the formalism of Keldysh's nonequilibrium Green function, we establish a two momenta spinor Boltzmann equation for longitudinal scalar distribution function and transverse vector distribution function. Th... Based on the formalism of Keldysh's nonequilibrium Green function, we establish a two momenta spinor Boltzmann equation for longitudinal scalar distribution function and transverse vector distribution function. The longitudinal charge currents, transverse spin currents and the continuity equations satisfied by them are then studied, it indicates that both the charge currents and spin currents decay oscillately along with position, which is due to the momenta integral over the Fermi surface. We also compare our charge currents and spin currents with the corresponding results of one momentum spinor Boltzmann equation, the differences are obvious. 展开更多
关键词 spin polarized transport spinor Boltzmann equation spin current
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A Lower Bound on Longitudinal Structure Function at Small x from a Self-Similarity Based Model of Proton
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作者 Akbari Jahan D.K.Choudhury 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第5期654-658,共5页
Self-similarity based model of proton structure function at small x was reported in the literature sometime back. The phenomenological validity of the model is in the kinematical region 6.2 × 10-7 ≤ x ≤ 10-2 an... Self-similarity based model of proton structure function at small x was reported in the literature sometime back. The phenomenological validity of the model is in the kinematical region 6.2 × 10-7 ≤ x ≤ 10-2 and 0.045 ≤ Q2 ≤ 120 GeV2. We use momentum sum rule to pin down the corresponding self-similarity-based gluon distribution function valid in the same kinematical region. The model is then used to compute bound on the longitudinal structure function FL(X, Q2) for A1tarelli-Martinelli equation in QCD and is compared with the recent HERA data. 展开更多
关键词 SELF-SIMILARITY small x longitudinal structure function QCD
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