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911.
弱DEA有效性(C^2GS^2)的研究 总被引:2,自引:0,他引:2
本证明了一个[1]中所述的有关弱DEA有效性(C^2GA^2)的定理,答复了[2]中所提出的问题。 相似文献
912.
超有效意义下向量集值优化修整的Lagrange乘子型对偶 总被引:2,自引:0,他引:2
给出了一类加细的向量集值优化超有效解的最优性条件,由此给出了一种改进的Lagrange乘子型对偶,并建立了对偶的弱定理,正定理及逆定理。 相似文献
913.
914.
Quantum thermal machines make use of non-classical thermodynamic resources, one of which include interactions between elements of the quantum working medium. In this paper, we examine the performance of a quasi-static quantum Otto engine based on two spins of arbitrary magnitudes subject to an external magnetic field and coupled via an isotropic Heisenberg exchange interaction. It has been shown earlier that the said interaction provides an enhancement of cycle efficiency, with an upper bound that is tighter than the Carnot efficiency. However, the necessary conditions governing engine performance and the relevant upper bound for efficiency are unknown for the general case of arbitrary spin magnitudes. By analyzing extreme case scenarios, we formulate heuristics to infer the necessary conditions for an engine with uncoupled as well as coupled spin model. These conditions lead us to a connection between performance of quantum heat engines and the notion of majorization. Furthermore, the study of complete Otto cycles inherent in the average cycle also yields interesting insights into the average performance. 相似文献
915.
This paper studies the asymptotic behavior of the minimum Hellinger distance estimator of the underlying parameter in a supercritical branching process whose offspring distribution is known to belong to a parametric family. This estimator is shown to be asymptotically normal, efficient at the true model and robust against gross errors. These extend the results of Beran (Ann. Statist. 5, 445–463 (1977)) from an i.i.d., continuous setup to a dependent, discrete setup. 相似文献
916.
线性模型参数估计的一种新的相对效率 总被引:2,自引:0,他引:2
本文对线性模型的最小二乘估计(LSE)与最佳线性无偏估计(BLUE)提出了一种新的相对效率并给出了新的相对效率的上、下界,最后还讨论了新的相对效率与已有的几种相对效率的关系。 相似文献
917.
Here we study the problems of local asymptotic normality of the parametric family of distributions and asymptotic minimax efficient estimators when the observations are subject to right censoring. Local asymptotic normality will be established under some mild regularity conditions. A lower bound for local asymptotic minimax risk is given with respect to a bowl-shaped loss function, and furthermore a necessary and sufficient condition is given in order to achieve this lower bound. Finally, we show that this lower bound can be attained by the maximum likelihood estimator in the censored case and hence it is local asymptotic minimax efficient. 相似文献
918.
黄龙光 《纯粹数学与应用数学》2000,16(3):41-44,50
研究多目标凸向量优化问题在Gateaux可微条件下弱有效解的特性,并讨论一类非凸向量最优化问题弱有效解及与一变分不等式的等价性,给出了解的存在性。 相似文献
919.
The decrease of initiation efficiency (radical entry efficiency) during seeded emulsion copolymerizations of styrene and butyl acrylate with different residual monomer reduction strategies was evaluated. Experiments were carried out using 50 and 99wt.% of styrene in monomer feed stream. Simulations were performed with a detailed mathematical model of the process that takes into account the diffusion control of initiation, propagation and termination. Results showed that the radical entry into polymer particles is strongly influenced by the aqueous phase kinetics and by the monomer solubility in aqueous phase. Simulation results were compared to experimental results of residual monomer and showed that the residual monomer content can be reduced by a temperature increase at the end of the polymerization. However, an additional feeding of more initiator, even when combined with such an increase of temperature, did not lead to a smaller residual monomer content due, mainly, the kinetic of termination in aqueous phase and radical anchoring. A model that accounts for the reduction of initiator efficiency (free radical entry efficiency) was successfully used to explain the behavior of the experimental observations and was able to correctly predict the qualitative trends of the effectiveness of different residual monomer reduction strategies. 相似文献
920.
对螺旋型旋风分离器进行了两相流场的三维数值模拟.气体流场通过求解三维N-S方程得到,湍流模型采用了雷诺应力模型.计算结果表明,旋风分离器内部的流场分为两部分:螺旋通道内比较稳定的流场和筒体中心区域的复合涡结构流场.对颗粒运动轨迹的计算表明,颗粒在入口处的初始位置对颗粒分离有比较显著的影响.同时得到了不同入口速度下颗粒的分级效率曲线,并给出了气体流量对旋风分离器性能的影响,结果显示:气体流量的增加会提高分离效率,但同时导致压力损失的急剧增加. 相似文献