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951.
针对目前指标体系在构建和评价方面缺乏统一理论与方法这一现状,在不考虑具体评价问题的基础上,对一般意义上的指标体系进行了构建原理与评价方法研究.从时间维、方法维和逻辑维三方面对构建方法进行了阐述;建立了指标体系的数学模型,并提出了基于正交实验设计的指标权重计算方法;以合理指标体系的基本要素为依据,定量地分析了体系的完备性和指标间的相关性. 相似文献
952.
953.
研究了广义Ekeland变分原理在拟度量空间中的一些重要应用.利用广义Ekeland变分原理证明了函数f满足关于α的Takahashi ε-条件当且仅当f满足关于相同α的Hamel ε-条件.此外,利用关于α的Takahashi ε-条件得到了一些重要结论. 相似文献
954.
Bing Sun 《Nonlinear Analysis: Real World Applications》2012,13(1):325-332
In this paper, the optimal distributed control of the viscous Dullin-Gottwald-Holm equation is investigated. Adopting the Dubovitskii and Milyutin functional analytical approach, we obtain the Pontryagin maximum principle of the system. The necessary optimality condition is established for an optimal control problem in fixed final horizon case. Finally, an illustrative example is also given. 相似文献
955.
In this paper, we present a new proof of the uniqueness of Koebe-Andreev-Thurston theorem. Our method is based on the argument principle in complex analysis and reviews the connection between the circle packing theorem and complex analysis. 相似文献
956.
957.
《复变函数与椭圆型方程》2012,57(9):739-752
This article deals with the solvability of the CR equation rw = (A0(θ) ? O(rα))w ? (B0(θ) ? O(rα)), where z = r eiθ and where A0, B0 are continuous and 2π-periodic. The solutions of this equation are shown to be similar to those of the model equation rw = A0(θ)w ? B0(θ). The solutions of the model equation are completely characterized by using dynamical systems and Fourier techniques. 相似文献
958.
We briefly discuss the current status of Mach's principle in general relativity and point out that its last vestige, namely, the gravitomagnetic field associated with rotation, has recently been measured for the earth in the GP‐B experiment. Furthermore, in his analysis of the foundations of Newtonian mechanics, Mach provided an operational definition for inertial mass and pointed out that time and space are conceptually distinct from their operational definitions by means of masses. Mach recognized that this circumstance is due to the lack of any a priori connection between the inertial mass of a body and its Newtonian state in space and time. One possible way to improve upon this situation in classical physics is to associate mass with an extra dimension. Indeed, Einstein's theory of gravitation can be locally embedded in a Ricci‐flat 5D manifold such that the 4D energy‐momentum tensor appears to originate from the existence of the extra dimension. An outline of such a 5D Machian extension of Einstein's general relativity is presented. 相似文献
959.
Fractional differential equations of motion in terms of combined Riemann—Liouville derivatives 下载免费PDF全文
In this paper,we focus on studying the fractional variational principle and the differential equations of motion for a fractional mechanical system.A combined Riemann-Liouville fractional derivative operator is defined,and a fractional Hamilton principle under this definition is established.The fractional Lagrange equations and the fractional Hamilton canonical equations are derived from the fractional Hamilton principle.A number of special cases are given,showing the universality of our conclusions.At the end of the paper,an example is given to illustrate the application of the results. 相似文献
960.
The Pauli principle is included in a multisubband deterministic solver for two-dimensional devices without approximations.The nonlinear Boltzmann equations are treated properly without compromising on accuracy,convergence,or CPU time.The simulation results indicate the significant impact of the Pauli principle on the transport properties of the quasi-2D electron gas,especially for the on state. 相似文献