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在平衡双重半拟补MS代数上引入(*)理想,(+)理想,(°)理想和(*,+,°)理想的概念,探讨平衡双重半拟补MS代数上(*)理想,(+)理想,(°)理想和(*,+,°)理想与核理想的关系,获得了(°)理想是核理想的结论.同时构造出了以(*,+,°)理想为核的最小同余关系和最大同余关系,并获得了最小同余关系和最大同余关... 相似文献
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运用泛代数和格理论的方法和原理进一步深入研究有界Heyting代数的理想问题。在有界Heyting代数中引入了交换理想、关联理想和正关联理想概念并讨论了它们的性质和相互关系。获得了各种理想的若干等价刻画。证明了在有界Heyting代数中,关联理想和正关联理想等价;在Ockham型有界Heyting代数中,理想和交换理想等价。同时,给出了有界Heyting代数的交换理想成为关联理想的一个充分必要条件。 相似文献
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给出Quantale代数的概念,得到了单位Quantale是Quantale代数的充要条件,讨论了理想与代数理想的关系,找到了理想不是代数理想的具体例子以及理想是代数理想的充分条件. 相似文献
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引入了亚BCI-代数的模糊子代数、模糊理想、闭模糊理想和模糊P-理想的概念,研究了它们的性质。证明了模糊子代数(模糊理想、闭模糊理想、模糊P-理想)的同态像与同态原像仍能成为模糊子代数(模糊理想、闭模糊理想、模糊P-理想)。 相似文献
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BCK-代数的Ω-模糊正定关联理想 总被引:1,自引:0,他引:1
彭家寅 《数学的实践与认识》2010,40(2)
给定一个集合Ω,引入了BCK-代数的Ω-模糊正定关联理想的概念,给出了一些恰当的例子,讨论了BCK-代数的Ω-模糊理想与Ω-模糊正定关联理想的关系.利用模糊正定关联理想,刻画了Ω-模糊正定关联理想.反之,模糊正定关联理想通过Ω-模糊正定关联理想来构造.证明了Ω-模糊正定关联理想(Ω-模糊理想)的同态原象仍是Ω-模糊理想(Ω-模糊理想). 相似文献
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首先,在正则剩余格中引入模糊理想基的概念,介绍了模糊理想基的一些重要性质,并且利用这些性质,给出了模糊理想基的三种等价形式;其次,结合具体实例讨论了模糊理想基与模糊理想的关系;最后,给出由模糊集生成模糊理想基及由模糊理想基生成模糊理想的方法. 相似文献
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在扩大模型下,用超理想的单子对超理想进行刻画;进而用它给出了理想为超理想的条件;最后给出理想的单子与超理想的单子之间的关系. 相似文献
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BCI代数的软关联理想和软正定关联理想 总被引:1,自引:0,他引:1
给出BCI代数的软关联理想和软正定关联理想的概念,讨论软理想、软关联理想和软正定关联理想三者之间的关系,研究了两个软关联理想(软正定关联理想)的扩展交、限制交、限制并和限制差分的性质。 相似文献
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1. IntroductionIn the numerical simulation of the Navier-Stokes equations one encounters three seriousdifficulties in the case of large Reynolds numbers f the treatment of the incomPressibility con-dition divu = 0, the treatment of the noIilinear terms and the large time integration. For thetreatment of the incoInPressibility condition, one use the penalty method in the case of finiteelemellts [1--2l and for the treatmen of the noulinar terms and the large tfor integration, oneuse the nonlin… 相似文献
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非正则条件下类Wilson元的构造及其应用 总被引:3,自引:1,他引:2
本文在非正则性条件下,研究了窄四边形上的类Wilson元。通过参考元上类Wilson元的构造,证明了由此产生的有限元对任意窄四边形剖分通过Irons分片检查,得到了二阶问题的误差估计。结果表明,该单元的收敛性质与Wilson元的类似。 相似文献
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Rail-bridge coupling element of unequal lengths for analysing train-track-bridge interaction systems
This paper presents a rail-bridge coupling element of unequal lengths, in which the length of a bridge element is longer than that of a rail element, to investigate the dynamic problem of train-track-bridge interaction systems. The equation of motion in matrix form is given for a train-track-bridge interaction system with the proposed element. The first two numerical examples with two types of bridge models are chosen to illustrate the application of the proposed element. The results show that, for the same length of rail element, (1) the dynamic responses of train, track and bridge obtained by the proposed element are almost identical to those obtained by the rail-bridge coupling element of equal length, and (2) compared with the rail-bridge coupling element of equal length, the proposed element can help to save computer time. Furthermore, the influence of the length of rail element on the dynamic responses of rail is significant. However, the influence of the length of rail element on the dynamic responses of bridge is insignificant. Therefore, the proposed element with a shorter rail element and a longer bridge element may be adopted to study the dynamic responses of a train-track-bridge interaction system. The last numerical example is to investigate the effects of two types of track models on the dynamic responses of vehicle, rail and bridge. The results show that: (1) there are differences of the dynamic responses of vehicle, rail and bridge based on the single-layer and double-layer track models, (2) the maximum differences increase with the increase of the mass of sleeper, (3) the double-layer track model is more accurate. 相似文献
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半导体器件瞬态模拟的对称正定混合元方法 总被引:3,自引:3,他引:0
提出具有对称正定特性的混合元格式求解非稳态半导体器件瞬态模拟问题。提出一个最小二乘混合元方法、一个新的具有分裂和对称正定性质的混合元格式和一个解经典混合元方程的对称正定失窃工格式求解电场位势和电场强度方程;提出一个最小二乘混合元格式求解关于电子与空穴浓度的非稳态对流扩散方程,浓度函数和流函数被同时求解;采用标准的有限元方法求解热传导方程。建立了误差分析理论。 相似文献
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本文研究对称椭圆特征值问题的有限元后验误差估计,包括协调元和非协调元,具有下列特色:(1)对协调/非协调元建立了有限元特征函数uh的误差与相应的边值问题有限元解的误差在局部能量模意义下的恒等关系式,该边值问题的右端为有限元特征值λh与uh的乘积,有限元解恰好为uh.从而边值问题有限元解在能量模意义下的局部后验误差指示子,包括残差型和重构型后验误差指示子,成为有限元特征函数在能量模意义下的局部后验误差指示子.(2)讨论了协调有限元特征函数的基于插值后处理的梯度重构型后验误差估计,对有限元特征函数的导数得到了最大模意义下的渐近准确局部后验误差指示子. 相似文献
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In this paper, a family of 3-dimensional elements different from isoparametric serendipity is developed according to the variational principle and the convergence criteria of the mixed stiffness finite element method. For the new family, which is named mixed stiffness elements, the number of nodes on the quadratic element is not 20 but 14. Theoretical analysis and various computational comparisons have found the mixed stiffness element superior over the isoparametric serendipity element, especially a substantial improvement in computational efficiency can be achieved by replacing the 20 node-isoparametric element with the 14-node mixed stiffness element. 相似文献
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Let $R$ be a ring with involution. It is well-known that an EP
element in $R$ is a core invertible element, but the question when a
core invertible element is an EP element, the authors answer in this
paper. Several new characterizations of star-core, normal and
Hermitian elements in $R$ are also presented. 相似文献
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In the stability analysis of frame structures, the results by conventional finite element method (FEM) in which one member is taken as one element are sometimes unavailable. This paper took a new basic function system with bubble functions as the shape function of a bar element to develop a bubble function finite element method (BFEM), in which the bending and the geometric stiffness matrices were derived from the principle of virtual work. Bubble functions are finite element modes that are located entirely within a single element and are zero on boundaries of the element, but are nonzero at the other points. BFEM is as concise as conventional bar FEM but has better accuracy, and is adaptable to the buckling analysis of all kinds of frame structures. The use of bubble functions significantly improves the convergence of finite element analysis, and efficiently reduces the computation cost for the buckling analysis of frame structures. Numerical results show that using bubble functions in finite element for the stability analysis of structures is very efficient, especially for high-rise and large-scale frame structures. 相似文献