共查询到20条相似文献,搜索用时 31 毫秒
1.
Raul Antonio Ferraz 《代数通讯》2013,41(2):851-872
The goal of this article is to describe a multiplicatively independent set, which generates the group of units of the integral group ring ?G, where G is either the cyclic group of order 2p or C2 × C2 × Cp, for a prime number p that satisfies some suitable conditions that will be specified later. 相似文献
2.
3.
Julia Porcino 《代数通讯》2015,43(1):84-101
We analyze the structure of ideals generated by some classes of 2 × 2 permanents of hypermatrices, generalizing [9] on 2 × 2 permanental ideals of generic matrices. We compare the obtained structure to that of the corresponding determinantal ideals in [11]: as expected, the permanental ideals have many more (minimal) components. In the last two sections, we examine a few related classes of permanental ideals. 相似文献
4.
Zhaoxiang Li Erling Wei Jie Xu Yanpei Liu 《Journal of Applied Mathematics and Computing》2010,34(1-2):71-80
This paper provides the chromatic sum function equations of rooted 2-edge-connected maps on the projective plane. The enumerating function equations of rooted 2-edge-connected loopless maps and rooted 2-edge-connected bipartite maps on the projective plane are derived by the chromatic sum function equation of rooted 2-edge-connected maps on the projective plane. 相似文献
5.
A. D. Sankey 《Journal of Algebraic Combinatorics》2010,32(1):133-153
Type-II matrices are nonzero complex matrices that were introduced in connection with spin models for link invariants. Type-II
matrices have been found in connection with symmetric designs, sets of equiangular lines, strongly regular graphs, and some
distance regular graphs. We investigate weighted complete and strongly regular graphs, and show that type-II matrices arise
in this setting as well. 相似文献
6.
The strong normalization theorem is uniformly proved for typed λ-calculi for a wide range of substructural logics with or
without strong negation.
We would like to thank the referees for their valuable comments and suggestions. This research was supported by the Alexander
von Humboldt Foundation. The second author is grateful to
the Foundation for providing excellent working conditions and generous support of this research.
This work was also supported by the Japanese Ministry of Education, Culture, Sports, Science
and Technology, Grant-in-Aid for Young Scientists (B) 20700015, 2008. 相似文献
7.
A ring R is quasipolar if for any a ∈ R, there exists p 2 = p ∈ R such that p ∈ comm2(a), p + a ∈ U(R) and ap ∈ R qnil . In this article, we determine when a 2 × 2 matrix over a commutative local ring is quasipolar. A criterion in terms of solvability of the characteristic equation is obtained for such a matrix to be quasipolar. Consequently, we obtain several equivalent conditions for the 2 × 2 matrix ring over a commutative local ring to be quasipolar. Furthermore, it is shown that the 2 × 2 matrix ring over the ring of p-adic integers is quasipolar. 相似文献
8.
We study the effect of a magnetic field on the behaviour of a slender conducting elastic structure, motivated by stability
problems of electrodynamic space tethers. Both static (buckling) and dynamic (whirling) instability are considered and we
also compute post-buckling configurations. The equations used are the geometrically exact Kirchhoff equations. Magnetic buckling
of a welded rod is found to be described by a surprisingly degenerate bifurcation, which is unfolded when both transverse
anisotropy of the rod and angular velocity are considered. By solving the linearised equations about the (quasi-) stationary
solutions, we find various secondary instabilities. Our results are relevant for current designs of electrodynamic space tethers
and potentially for future applications in nano- and molecular wires. 相似文献
9.
Let k≥1 be an integer and G=(V 1,V 2;E) a bipartite graph with |V 1|=|V 2|=n such that n≥2k+2. Our result is as follows: If $d(x)+d(y)\geq \lceil\frac{4n+k}{3}\rceil$ for any nonadjacent vertices x∈V 1 and y∈V 2, then for any k distinct vertices z 1,…,z k , G contains a 2-factor with k+1 cycles C 1,…,C k+1 such that z i ∈V(C i ) and l(C i )=4 for each i∈{1,…,k}. 相似文献
10.
Omar Hirzallah Fuad Kittaneh Khalid Shebrawi 《Integral Equations and Operator Theory》2011,71(1):129-147
We prove several numerical radius inequalities for certain 2 × 2 operator matrices. Among other inequalities, it is shown that if X, Y, Z, and W are bounded linear operators on a Hilbert space, thenandAs an application of a special case of the second inequality, it is shown thatwhich is a considerable improvement of the classical inequality \({\frac{ \left\Vert X\right\Vert }{2}\leq w(X)}\) . Here w(·) and || · || are the numerical radius and the usual operator norm, respectively.
相似文献
$$w\left( \left[\begin{array}{cc} X &; Y \\ Z &; W \end{array} \right] \right) \geq \max \left(w(X),w(W),\frac{w(Y+Z)}{2},\frac{w(Y-Z)}{2}\right) $$
$$w\left( \left[\begin{array}{cc}X &; Y \\ Z &; W\end{array} \right] \right) \leq \max \left( w(X), w(W)\right)+\frac{w(Y+Z)+w(Y-Z)}{2}. $$
$$\frac{\left\Vert X\right\Vert }{2}+\frac{\left\vert \left\Vert\operatorname{Re}{X}\right\Vert -\frac{\left\Vert X\right\Vert}{2}\right\vert }{4}+\frac{ \left\vert \left\Vert \operatorname{Im}{X}\right\Vert -\frac{\left\Vert X\right\Vert}{2}\right\vert }{4} \leq w(X), $$
11.
Let \(T_n(\mathbb {F})\) and \(UT_n(\mathbb {F})\) be the semigroups of all upper triangular \(n\times n\) matrices and all upper triangular \(n\times n\) matrices with 0s and/or 1s on the main diagonal over a field \(\mathbb {F}\) with \(\mathsf {char}(\mathbb {F})=0\), respectively. In this paper, we address the finite basis problem for \(T_2(\mathbb {F})\) and \(UT_2(\mathbb {F})\) as involution semigroups under the skew transposition. By giving a sufficient condition under which an involution semigroup is nonfinitely based, we show that both \(T_2(\mathbb {F})\) and \(UT_2(\mathbb {F})\) are nonfinitely based, and that there is a continuum of nonfinitely based involution monoid varieties between the involution monoid variety \(\mathsf {var} UT_2(\mathbb {F})\) generated by \(UT_2(\mathbb {F})\) and the involution monoid variety \(\mathsf {var} T_2(\mathbb {F})\) generated by \(T_2(\mathbb {F})\). Moreover, \(\mathsf {var} UT_2(\mathbb {F})\) cannot be defined within \(\mathsf {var} T_2(\mathbb {F})\) by any finite set of identities. 相似文献
12.
G. van der Laan A. J. J. Talman Z. Yang 《Journal of Optimization Theory and Applications》2010,144(2):391-407
Tucker’s well-known combinatorial lemma states that, for any given symmetric triangulation of the n-dimensional unit cube and for any integer labeling that assigns to each vertex of the triangulation a label from the set
{±1,±2,…,±n} with the property that antipodal vertices on the boundary of the cube are assigned opposite labels, the triangulation admits
a 1-dimensional simplex whose two vertices have opposite labels. In this paper, we are concerned with an arbitrary finite
set D of integral vectors in the n-dimensional Euclidean space and an integer labeling that assigns to each element of D a label from the set {±1,±2,…,±n}. Using a constructive approach, we prove two combinatorial theorems of Tucker type. The theorems state that, under some
mild conditions, there exists two integral vectors in D having opposite labels and being cell-connected in the sense that both belong to the set {0,1}
n
+q for some integral vector q. These theorems are used to show in a constructive way the existence of an integral solution to a system of nonlinear equations
under certain natural conditions. An economic application is provided. 相似文献
13.
We propose and analyze a perturbed version of the classical Josephy–Newton method for solving generalized equations. This
perturbed framework is convenient to treat in a unified way standard sequential quadratic programming, its stabilized version,
sequential quadratically constrained quadratic programming, and linearly constrained Lagrangian methods. For the linearly
constrained Lagrangian methods, in particular, we obtain superlinear convergence under the second-order sufficient optimality
condition and the strict Mangasarian–Fromovitz constraint qualification, while previous results in the literature assume (in
addition to second-order sufficiency) the stronger linear independence constraint qualification as well as the strict complementarity
condition. For the sequential quadratically constrained quadratic programming methods, we prove primal-dual superlinear/quadratic
convergence under the same assumptions as above, which also gives a new result. 相似文献
14.
Stefania Aqué 《代数通讯》2013,41(4):1405-1416
Let F be a field of characteristic 0 and A = M 2, 1(F) the algebra of 3 × 3 matrices over F endowed with the only non trivial ?2-grading. Aver'yanov in [1] determined a set of generators for the T 2-ideal of graded identities of A. Here we study the identities in variables of homogeneous degree 1 via the representation theory of the symmetric group, and we determine the decomposition of the corresponding character into irreducibles. 相似文献
15.
Andrzej Derdzinski 《Journal of Geometric Analysis》2009,19(2):301-357
The local structure of the manifolds named in the title is described. Although curvature homogeneous, they are not, in general,
locally homogeneous. Not all of them are Ricci-flat, which answers an existence question about type III Jordan-Osserman metrics,
raised by Díaz-Ramos, García-Río and Vázquez-Lorenzo (J. Geom. Anal. 16, 39–52, 2006).
Work begun during the author’s visit to the University of Santiago de Compostela, supported by Grant MTM2006-01432 (Spain). 相似文献
16.
We describe a Mathematica package for dealing with q-holonomic sequences and power series. The package is intended as a q-analogue of the Maple package gfun and the Mathematica package GeneratingFunctions. It provides commands for addition, multiplication,
and substitution of these objects, for converting between various representations (q-differential equations, q-recurrence equations, q-shift equations), for computing sequence terms and power series coefficients, and for guessing recurrence equations given
initial terms of a sequence.
C. Koutschan partially supported by the Austrian Science Foundation (FWF) grants SFB F1305. 相似文献
17.
Jeffrey B. Vancouver Charles A. Scherbaum 《Computational & Mathematical Organization Theory》2008,14(1):1-22
Self-regulation theories in applied psychology disagree about whether action or perceptions are the focus of regulation. Computational
models based on the two conceptualizations were constructed and simulated. In one scenario, they performed identically and
in conjunction with participants in a study of the goal-level effect (Vancouver et al., Organ Res Methods 8:100–127, 2005). In another scenario they created differentiating predictions and only the computational model based on the self-regulation
of perceptions matched the data of participants. Implications for research and practice are discussed.
相似文献
Jeffrey B. VancouverEmail: |
18.
Douglas R. Anderson Richard I. Avery 《Journal of Applied Mathematics and Computing》2011,37(1-2):297-312
Green’s functions for new second-order periodic differential and difference equations with variable potentials are found, then used as kernels in integral operators to guarantee the existence of a positive periodic solution to continuous and discrete second-order periodic boundary value problems with periodic coefficient functions. A new version of the Leggett-Williams fixed point theorem is employed. 相似文献
19.
Barbara H. Jasiulis 《Journal of Theoretical Probability》2010,23(1):315-327
We denote by ? \((\mathcal{P_{+}})\) the set of all probability measures defined on the Borel subsets of the real line (the positive half-line [0,∞)). K. Urbanik defined the generalized convolution as a commutative and associative ?+-valued binary operation ? on ? + 2 which is continuous in each variable separately. This convolution is distributive with respect to convex combinations and scale changes T a (a>0) with δ 0 as the unit element. The key axiom of a generalized convolution is the following: there exist norming constants c n and a measure ν other than δ 0 such that \(T_{c_{n}}\delta_{1}^{\bullet n}\to\nu\).In Sect. 2 we discuss basic properties of the generalized convolution on ? which hold for the convolutions without the key axiom. This rather technical discussion is important for the weak generalized convolution where the key axiom is not a natural assumption. In Sect. 4 we show that if the weak generalized convolution defined by a weakly stable measure μ has this property, then μ is a factor of strictly stable distribution. 相似文献
20.
Matthias Börger 《Bl?tter der DGVFM》2010,31(2):225-259
In general, the capital requirement under Solvency II is determined as the 99.5% Value-at-Risk of the Available Capital. In the standard model’s longevity risk module, this Value-at-Risk is approximated by the change in Net Asset Value due to a pre-specified longevity shock which assumes a 25% reduction of mortality rates for all ages. We analyze the adequacy of this shock by comparing the resulting capital requirement to the Value-at-Risk based on a stochastic mortality model. This comparison reveals structural shortcomings of the 25% shock and therefore, we propose a modified longevity shock for the Solvency II standard model. We also discuss the properties of different Risk Margin approximations and find that they can yield significantly different values. Moreover, we explain how the Risk Margin may relate to market prices for longevity risk and, based on this relation, we comment on the calibration of the cost of capital rate and make inferences on prices for longevity derivatives. 相似文献