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1.
本文利用一个新的技巧建立了广义集值混合变分不等式与新的不动点问题的等价性。利用这个等价性,我们提出和分析了一类解集值混合变分不等式和相关的优化问题的新算法。我们的结果统一和改进了该领域内的一些最新结果。  相似文献   

2.
采用最小二乘法对弹性接触问题提出了一种新的混合变分形式,对该变分问题解的存在唯一性进行了论证。  相似文献   

3.
曹喜  张韫美 《工程力学》1997,(A01):227-234
本文介绍了工程力学中的一种 新的原理与解法-亦分不等方程解法的发展与应用范围,它比变分原理更具有一般性。  相似文献   

4.
罗恩  张贺忻 《工程力学》1998,(A01):48-54
在变形体动力学的变分原理及其应用方面的研究工作从1985年开始,至今已进行了十多年,本文主要从三个方面对此进行综述。1.原理的研究,提出一条新途径,其基本思想是古典阴阳互补和现代对偶互补,它的特点是完全不用拉格朗日乘子法,但能简单而系统地从一般到特殊建立各种变分原理,通过这条新途径,作者建立了某些变形动力学的一系列基本原理,其中很多是新的结果。2.原理的应用研究,提出了分别基于简化Gurtin型分  相似文献   

5.
本文从变域变分原理出发,提出了一种新的有限元方法,并将所提算法用于求解形状最优化问题。我们给出了最优化问题解的存在性及其离散形式。讨论了数值解的收敛性,给出了数值解与精确解之间的误差估计。最后给出了算法的具体实施步骤和一个具有代表性的数值算例,数值结果表明该算法是正确、高效的。  相似文献   

6.
压电材料变分原理逆问题的研究   总被引:10,自引:2,他引:8       下载免费PDF全文
研究了压电材料变分原理的逆问题, 采用文献[ 8 ]提出的变积方法, 系统地建立了压电材料的变分原理及其广义变分原理, 除得到文献中已有的结果外, 还得到了一些新的变分原理, 为建立压电材料的有限元分析模型提供了依据。  相似文献   

7.
何吉欢 《振动与冲击》1999,18(2):23-25,16
本文提出了求解非线性耦合系统的一种迭代算法,这种方法是应用广泛拉氏乘子构造较正泛函,然后用变分理论最佳识别。这种方法对初近似不敏感,也没有“小参数”的限制,可广泛用于非线性振动问题。  相似文献   

8.
用变分同化方法,在整体观测资料下,对一类简单的"on-off"模式中的初值进行修正.研究观测误差对于变分同化方法的影响,对变分同化方法反演得到的最优初值的收敛性以及误差进行分析,从理论上分析"on-off"问题变分同化方法的有效性.  相似文献   

9.
刘世奎 《工程力学》1995,(A01):215-221
针对一类广义边值问题,本文提出了推广Gauss-Green定理的数学恒等式和含参广义变分原理,导出了一些新的广义变分原理,并讨论了其特殊形式。  相似文献   

10.
一类弱非线性振动方程的变分迭代算法   总被引:1,自引:0,他引:1  
本文提出了一种求解非线性方程的迭代算法,这种方法是先给方程一个带待定函数的试函数作为初始近似解,然后用拉氏乘子法构造一个迭代公式,而拉氏乘子可用变分的概念最佳确定。应用这种方法不会出现长期项,其结果比传统的摄动方法要好得多。  相似文献   

11.
A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.  相似文献   

12.
An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.  相似文献   

13.
An analysis of anisotropy of the properties of a Bi2Se0.3Te2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied.  相似文献   

14.
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.  相似文献   

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16.
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.  相似文献   

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水三相点是开尔文热力学温度的唯一基准点,也是ITS-90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0.16mK(k=2.69,P=0.99)。  相似文献   

20.
可燃气体检测报警器测量结果的不确定度评定   总被引:1,自引:0,他引:1  
本文详细介绍了可燃气体检测报警器示值误差测量结果的不确定度评定方法。  相似文献   

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