共查询到20条相似文献,搜索用时 62 毫秒
1.
As a sequel to [23] we investigate ideal properties focusing on subtractive varieties. After having listed a few basic results, we give several characterizations of the commutator of ideals and prove, for example, that it commutes with finite direct products. We deal with the ideal extension property (IEP) and with related commutator properties, showing for instance that IEP implies that the commutator commutes with restriction to subalgebras. Then we characterize varieties with distributive ideal lattices and relate this property with (a form of) equationally definable principal ideals and with IEP. Then, at the other extreme, we deal with Abelian and Hamiltonian properties (of ideals and congruences), giving for example a purely ideal theoretic characterization of varieties of Abelian groups with linear operations. To finish with, we present a few examples aiming at vindicating our work.Presented by A. F. Pixley. 相似文献
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Kramer's sampling theorem forms a bridge between the Whittaker-Shannon-Kotel'nikov sampling theorem and boundary-value problems. It has been shown that sampling expansions associated with Sturm-Liouville boundary-value problems are Lagrange-type sampling series, i.e., Lagrange series with infinitely many terms converging to entire functions. String theory as developed by Feller, Kac, and Krein, is a generalization of the Sturm-Liouville theory. We investigate sampling series associated with strings and compare them with those associated with Sturm-Liouville problems. We show that unlike sampling series associated with Sturm-Liouville problems, those associated with strings include not only Lagrange-type sampling series, but also Lagrange polynomial interpolation. 相似文献
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Lai-Jiu Lin 《Journal of Global Optimization》2007,37(2):275-286
In this paper, we study the mathematical program with system of equilibrium constraints. This problem contains bilevel program
with system of equilibrium constraints, semi-infinite program with system of equilibrium constraints, mathematical program
with Nash equilibrium constraints, mathematical program with system of mixed variational like inequalities constraints. We
establish the existence theorems of mathematical program with system of equilibrium constraints under various assumptions. 相似文献
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M. V. Korovina 《Differential Equations》2010,46(5):702-710
The present paper deals with differential equations with edge degeneration in spaces with asymptotics. We give the definition
of an edge space with asymptotics, prove the continuity of operators with edge degeneration in the scale of these spaces,
present statements of problems with edge operators, and state conditions providing their Fredholm property. 相似文献
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A. N. Borodin 《Journal of Mathematical Sciences》2008,152(6):840-852
The paper deals with some transformations of diffusions with jumps. We consider the class of diffusions with jumps that is
closed with respect to composition with invertible, twice continuously differentiable functions. A special random time change
gives us again a diffusion with jumps. A result on transformation of a measure is valid for this class of diffusions with
jumps. Bibliographty: 6 titles.
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Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 351, 2007, pp. 79–100. 相似文献
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Four equivalent lot-sizing models 总被引:1,自引:0,他引:1
We study the following lot-sizing models that recently appeared in the literature: a lot-sizing model with a remanufacturing option, a lot-sizing model with production time windows, and a lot-sizing model with cumulative capacities. We show the equivalence of these models with a classical model: the lot-sizing model with inventory bounds. 相似文献
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Let V(A) (Vo (A)) be the lattice consisting of ϕ and all convex subgroupoids (with zero) of an o-groupoid A (with zero) with respect to
the union B∨C which is the convex subgroupoid generated by B∩C and the set-theoretical intersection. In this paper, we study
partially ordered groupoids (o-groupoids with zero) without proper convex subgroupoids (with zero), o-groupoids (with zero)
for which V(A) (Vo (A)) is a chain, is the Cartesian product of two chains, is modular, is distributive, is complemented, or has a finite length,
and also o-groupoids with zero and with associative powers (o-semigroups) in which every subgroupoid with zero (sub-semigroup)
is convex. Finally, we give some results about lattice-closed classes of o-groupoids. 相似文献
9.
Let P be the Petersen graph. The main results of this paper are the discovery of infinite families of chromatically equivalent pairs of P homeomorphs and the discovery of infinite families of flow equivalent pairs of P amallamorphs. In particular, three families of P homeomorphs with 8 parameters, five families with 7 parameters and many families with fewer parameters are obtained. Also one family of P amallamorphs with 9 parameters, three families with 7 parameters, seven families with 6 parameters and many families with fewer parameters are obtained. 相似文献
10.
In this paper, we give a survey of spanning trees. We mainly deal with spanning trees having some particular properties concerning
a hamiltonian properties, for example, spanning trees with bounded degree, with bounded number of leaves, or with bounded
number of branch vertices. Moreover, we also study spanning trees with some other properties, motivated from optimization
aspects or application for some problems. 相似文献
11.
In its simplest form the Tiebout hypothesis suggests that redistribution by local government is not sustainable because individuals, when confronted by negative net fiscal benefits, will vote with their feet, changing their residential locations to jurisdictions which offer a more favorable fiscal balance. It is usually thought, moreover, that they will move (e.g. from central city to suburbs) in descending order of income.Recognition of extended preference modifies this simple characterization of the tiebout process, in which the process of relocation is like ‘peeling an onion’. Any relocation sequence is possible, with either sympathy or antipathy. Even for sympathetic individuals with identical tastes, restrictive and unrealistic assumptions are required to predict, with certainty, that individuals with higher incomes would be the first to move. In particular the marginal tax rate must exceed unity. With antipathy, individuals with lower incomes may move before those with higher incomes, even if net fiscal benefits decrease with income, if they become more willing to begrudge transfers to others as their incomes increase. 相似文献
12.
We introduce the concept of Pierce sheaf for semirings with involution, an analog of Pierce sheaf for rings. We construct maximal spectrum, Pierce congruence, Pierce sheaf of semirings with involution, Pierce stalk of semiring with involution. We prove main theorem on the isomorphism of semiring with involution and semiring with involution of global sections of Pierce sheaf. 相似文献
13.
为了扩大现有研究的应用范围,基于max-min型模糊正则文法引入了max-*型模糊正则文法(其中*为特定t-模)的概念,讨论了max-*型模糊正则文法可以通过max-min型模糊正则文法在任意给定的逼近精度来逼近.研究表明,当t-模*满足一定的条件时,max-*型模糊正则文法与max-min型模糊正则文法在生成模糊语言能力方面是等价的. 相似文献
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G.R. Jahanshahloo F. Hosseinzadeh LotfiM. Rostamy Malkhalifeh M. Ahadzadeh Namin 《Applied Mathematical Modelling》2009
Data envelopment analysis (DEA) is a method to estimate the relative efficiency of decision-making units (DMUs) performing similar tasks in a production system that consumes multiple inputs to produce multiple outputs. So far, a number of DEA models with interval data have been developed. The CCR model with interval data, the BCC model with interval data and the FDH model with interval data are well known as basic DEA models with interval data. In this study, we suggest a model with interval data called interval generalized DEA (IGDEA) model, which can treat the stated basic DEA models with interval data in a unified way. In addition, by establishing the theoretical properties of the relationships among the IGDEA model and those DEA models with interval data, we prove that the IGDEA model makes it possible to calculate the efficiency of DMUs incorporating various preference structures of decision makers. 相似文献
17.
首先将直角坐标系中的横向变厚度薄板的大挠度方程,转化到极坐标系中的变厚度圆薄板的非对称大挠度方程· 此方程和极坐标系中径向、切向两个平衡方程联立求解· 将物理方程和中面应变非线性变形方程,代入3个平衡方程,可得用3个变形位移表示的3个非对称非线性方程· 用Fourier级数表示的解代入基本方程,获得相应的基本方程· 在周边夹紧边界条件下,用修正迭代法求解· 作为算例,研究了余弦形式载荷作用下的问题,还给出了载荷与挠度的特征曲线,曲线依据变厚度参数变化而变化,其结果和物理概念完全吻合· 相似文献
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首先,将经典合作博弈进行扩展,提出了一类模糊联盟合作博弈的通用形式,涵盖常见三种模糊联盟合作博弈,即多线性扩展博弈、比例模糊博弈与Choquet积分模糊博弈.比例模糊博弈、Choquet积分模糊博弈的Shapley值均可以作为一种特定形式下模糊联盟合作博弈的收益分配策略,但是对于多线性扩展博弈的Shapley值一直关注较少,因此利用经典Shapley值构造出多线性扩展博弈的Shapley值,以此作为一种收益分配策略.最后,通过实例分析了常见三类模糊联盟合作博弈的形式及其对应的分配策略,分析收益最大的模糊联盟合作对策形式及最优分配策略,为不确定情形下的合作问题提供了一定的收益分配依据. 相似文献
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Steve Butler Ron Graham Gerhard Guettler Colin Mallows 《Discrete and Computational Geometry》2010,44(3):487-507
An Apollonian configuration of circles is a collection of circles in the plane with disjoint interiors such that the complement
of the interiors of the circles consists of curvilinear triangles. One well-studied method of forming an Apollonian configuration
is to start with three mutually tangent circles and fill a curvilinear triangle with a new circle, then repeat with each newly
created curvilinear triangle. More generally, we can start with three mutually tangent circles and a rule (or rules) for how
to fill a curvilinear triangle with circles. 相似文献