WEIGHT PROPERTY FOR IDEALS OF U q (sl(2))

Let k be an arbitrary field of characteristic zero, and U be the quantized enveloping algebra U _q (sl(2)) over k. The aim of this present paper is to study the ideals of U at q not a root of unity. It turns out that every non-zero ideal of U can be generated by at most two highest weight vectors under the adjoint action, and by a sum of two highest weight vectors. This weight property make it possible to give a complete list of all prime (primitive, maximal) ideals of U according to their generators.     

Small sets of even type in finite projective planes of even order

The problem of determining the minimum weight and the minimum-weight vectors of the dual code of a finite projective plane has attracted much attention over the years. In this paper, we present a survey of the structure of possible small weight vectors in the dual code of planes of even order. In particular, we discuss small sets of even type in the plane that could give words of low weight in the dual code.     

Modeling graphs using dot product representations

Given a simple (weighted) graph, or a collection of graphs on a common vertex set, we seek an assignment of vectors to the vertices such that the dot products of these vectors approximate the weight/frequency of the edges. By transforming vertices into (low dimensional) vectors, one can bring geometric methods to bear in the analysis of the graph(s). We illustrate our approach on the Mathematicians Collaboration Graph [Grossman (1996) The Erdős number project, ] and the times series of Interstate Alliance Graphs (Gibler and Sarkees in J Peace Res 41(2):211–222, 2004).     

Optimal reconstruction of the solution of the wave equation from inaccurate initial data

In the present paper, we consider the problem of the optimal reconstruction of the solution of the wave equation from the approximate values of the Fourier coefficients of the function specifying the initial form of the string. For an operator defined on the weight space of vectors from l ₂, we present the solution of the more general problem of reconstruction from the approximate values of the coordinates of these vectors.     

Completeness of root vectors for a Douglis-Nirenberg elliptic problem with an indefinite weight in Lp spaces

We establish the completeness of root vectors for a non-selfadjoint Douglis-Nirenberg elliptic problem with an indefinite weight matrix in appropriate L_p Sobolev spaces.     

Small sets of even type and codewords

We examine some geometric configurations of points in designs that give rise to vectors in the codes associated with the designs. In particular we look at small sets of points in projective planes of even order that are met evenly by all the lines of the plane, and find vectors of small weight in the binary hull and in the code's orthogonal. Dedicated to Professor Helmut Karzel on the occasion of his 70^th birthday     

一种群决策专家客观权重确定的改进方法

针对传统的群决策专家客观权重确定的两类主要方法(即基于判断矩阵一致性程度和基于专家排序向量或判断矩阵元素的聚类分析)的缺陷,提出了一种综合考虑两方面因素的改进方法.首先利用聚类分析方法根据各专家的排序向量得到专家类别间的权重,然后根据单个专家的判断矩阵一致性以及排序向量到类核心的距离确定最终权重.文末给出的算例表明该方法是可行、有效的.     

Generalized skew-elliptical distributions and their quadratic forms

This paper introduces generalized skew-elliptical distributions (GSE), which include the multivariate skew-normal, skew-t, skew-Cauchy, and skew-elliptical distributions as special cases. GSE are weighted elliptical distributions but the distribution of any even function in GSE random vectors does not depend on the weight function. In particular, this holds for quadratic forms in GSE random vectors. This property is beneficial for inference from non-random samples. We illustrate the latter point on a data set of Australian athletes.     

Partial differential equation approach to F 4

Singular vectors of a representation of a finite-dimensional simple Lie algebra are weight vectors in the underlying module that are nullified by positive root vectors. In this article, we use partial differential equations to explicitly find all the singular vectors of the polynomial representation of the simple Lie algebra of type F ₄ over its 26-dimensional basic irreducible module, which also supplements a proof of the completeness of Brion’s abstractly described generators. Moreover, we show that the number of irreducible submodules contained in the space of homogeneous harmonic polynomials with degree k ⩾ 2 is greater than or equal to 〚k/3〛 + 〚(k − 2)/3〛 + 2.     

Interval weight generation approaches for reciprocal relations

In this paper, we propose methods to derive interval weight vectors from reciprocal relations for reflecting the inconsistency when decision makers provide preferences over alternatives (or criteria). Several goal programming models are established to minimize the inconsistency based on multiplicative and additive consistency, respectively. Especially, if we obtain a crisp weight vector from a reciprocal relation, then it is consistent. Then, we extend the proposed methods to incomplete reciprocal relations and interval reciprocal relations and develop the corresponding models to derive interval weight vectors. Several examples are also given to compare the developed methods with the existing ones.     

基于最大离差和最大联合熵的多方案优选方法

针对多方案优选中指标权重确定问题,提出了基于最小离散和最大广义联合熵的组合赋权方法,建立了组合权系数优化模型。该方法一方面根据评价指标对方案决策所起作用大小赋予不同的权重;另一方面尽量能够消除组合赋权中的不稳定性,使各方法各指标权数赋予平衡因子后广义的联合熵最大,从而使得全局的不确定性最小。最后通过实例说明了此方法合理、稳健。     

Classification and generation of disturbance vectors for collision attacks against SHA-1

The main contribution of this paper is to provide a classification of disturbance vectors used in differential collision attacks against ${\tt{SHA}-1}$ . We show that all published disturbance vectors can be classified into two types of vectors, type-I and type-II. We present a deterministic algorithm which produce efficient disturbance vectors with respect to any given cost function. We define two simple cost functions to evaluate the efficiency of a candidate disturbance vector. Using our algorithm and those cost function we retrieved all previously known vectors and found that the most efficient disturbance vector is the one first reported as Codeword2 by Jutla and Patthak, A matching lower bound on the minimum weight of SHA-1 expansion code. Cryptology ePrint Archive, Report 2005/266, (2005). We also present a statistical evaluation of local collisions?? holding probabilities and show that the common assumption of local collision independence is flawed.     

Implementing stochastic multicriteria acceptability analysis

Stochastic multicriteria acceptability analysis (SMAA) is a family of methods for aiding multicriteria group decision making in problems with inaccurate, uncertain, or missing information. These methods are based on exploring the weight space in order to describe the preferences that make each alternative the most preferred one, or that would give a certain rank for a specific alternative. The main results of the analysis are rank acceptability indices, central weight vectors and confidence factors for different alternatives. The rank acceptability indices describe the variety of different preferences resulting in a certain rank for an alternative, the central weight vectors represent the typical preferences favouring each alternative, and the confidence factors measure whether the criteria measurements are sufficiently accurate for making an informed decision.     

Irreducibility of Certain Universal Holomorphic Harish-Chandra Modules

Abstract

We give a short proof of the irreducibility of Harish-Chandra modules of sufficiently high highest weight of the lowest K-type for the groups Sp _n (?) and U( p, q). The proof uses the action of the Casimir operator on holomorphic highest weight vectors and elementary inequalities.     

基于相对熵的多属性决策组合赋权方法

综合各种赋权方法给出的主观和客观属性权重信息,建立了求解多属性决策问题属性权重的优化模型,并改进了文献[11]中模型的求解方法.根据各种主客观赋权法给出的赋权结果的贴近度确定其在权重集成中的加权系数,贴近度通过计算权重向量的相对熵来得到,最后通过应用实例对此方法予以说明.     

由某些函数构造的状态变权

研究状态变权的构造问题,给出一种由多元函数和已知状态变权构造新状态变权和三种由多元函数直接构造状态变权的方法。特别地,证明了文[5]由状态均值构造状态变权的方法都可看作是函数构造状态变权的特例,并进一步给出一种基于几何均值的状态变权构造方法。     

基于离散点和法矢的曲线重构算法

This paper presents a curve reconstruction algorithm based on discrete data points and normal vectors using B-splines.The proposed algorithm has been improved in three steps:parameterization of the discrete data points with tangent vectors,the B-spline knot vector determination by the selected dominant points based on normal vectors,and the determination of the weight to balancing the two errors of the data points and normal vectors in fitting model.Therefore,we transform the B-spline fitting problem into three sub-problems,and can obtain the B-spline curve adaptively.Compared with the usual fitting method which is based on dominant points selected only by data points,the B-spline curves reconstructed by our approach can retain better geometric shape of the original curves when the given data set contains high strength noises.     

Counting matrices over finite fields having a given number of rows of unit weight

We present a formula enumerating matrices over a finite field of a given rank and a given number of rows of unit weight, i.e., each having a single nonzero entry. We also determine the number of subspaces of a given dimension containing a given number of vectors of unit weight.