计算对称群S9的所有交换子群

利用对称群的一些简单性质,设计了一种计算对称群S9所有交换子群的有效算法.利用计算机在较短的时间里计算出了S9的全部279 455个交换子群,并将它们分为72个共轭类,而且每个交换子群给出了一个最小生成元组.     

The importance of distinguishing between constructs and methods when comparing predictors in personnel selection research and practice.

The authors highlight the importance and discuss the criticality of distinguishing between constructs and methods when comparing predictors. They note that comparisons of constructs and methods in comparative evaluations of predictors result in outcomes that are theoretically to conceptually uninterpretable and thus potentially misleading. The theoretical and practical implications of the distinction between predictor constructs and predictor methods are discussed, with three important streams of personnel psychology research being used to frame this discussion. Researchers, editors, reviewers, educators, and consumers of research are urged to carefully consider the extent to which the construct-method distinction is made and maintained in their own research and that of others, especially when predictors are being compared. It is hoped that this discussion will reorient researchers and practitioners toward a more construct-oriented approach that is aligned with a scientific emphasis in personnel selection research and practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

一类无限群——SSC—群

若群Ｇ的每真子群Ｈ中同阶元均是Ｇ－共轭的,则称Ｇ为ＳＳＣ－群。给出了ＳＳＣ－群的几个性质,并刻划了可解ＳＳＣ－解。     

Some algebraic applications of soft sets

The paper presents an algebraic construction of the basic notions of soft set theory. Here we introduce the definition of bijective soft groups, dependent and independent soft groups. Some of their properties are investigated. Also we investigate the relationships between bijective soft groups and classical groups. In addition, we express some applications of bijective soft groups on coding theory.     

基于椭圆曲线的KDM安全公钥加密方案

某些场合下敌手能够获取与私钥有关消息的密文,大多现有加密方案在上述情况下是不安全的。为抵抗这种攻击,给出一般子群不可区分困难假设的一个实例——椭圆曲线子群不可区分困难假设,并设计相应的归约算法。在此基础上,提出一个基于环 上椭圆曲线的公钥加密方案,并将该方案中的密文不可区分问题归约到椭圆曲线子群不可区分困难的假设上。分析结果证明,该方案在此假设下是安全的。     

基于量子克隆的二面体群隐含子群问题量子算法的研究

基于最短向量问题的格公钥密码体制是典型的抗量子计算密码体制。格的唯一最短向量问题可转化为二面体群的隐含子群问题。有效地求解二面体群的隐含子群问题可攻破基于格的唯一最短向量问题的公钥密码体制。Kuperberg提出了二面体群隐含子群问题的半指数级量子算法。通过研究Kuperberg量子算法,利用概率量子克隆,文中提出了二面体群隐含子群问题的多项式时间量子算法。     

改进的混合粒子群算法

从研究分析粒子群算法和郭涛算法的特点出发,提出一种综合两算法优点的混合算法。新算法改变了粒子的更新方式,以子空间搜索和串行搜索相结合的多点并行搜索,扩大了算法的搜索范围,减少了粒子对初值的依赖,增强了算法跳出局部最优的能力;通过后代较优个体变异产生子群,提高了算法局部寻优能力;实验证明,该算法正确高效。     

Carter subgroups of singular classical groups over finite fields

Let Fq be a finite field with qelements where q = p^α. In the present paper, the authors study the existence and structure of Carter subgroups of singular symplectic group Spn 1,n(Fq), singular unitary group Un t,n(Fq2) and singular orthogonal group On 1,n(Fq) (n is even) over finite fields Fq.     

反模糊软子群诱导的商群

介绍正规反模糊软子群的概念,给出正规反模糊软子群的同构像定理和同态逆像定理,对反模糊软子群诱导的商群的一些基本性质进行了研究。     

Development of a hybrid method to improve the sensitivity and uncertainty analysis for homogenized few-group cross sections

In the framework of two-step method of reactor core calculation, few-group homogenized cross sections generated by lattice-physics calculations are key input parameters for the three-dimensional full-core calculation. Conventional method for few-group cross-sections sensitivity and uncertainty (S&U) analysis related to the nuclear data was performed based on the effective self-shielding cross sections instead of the continuous-energy cross sections, which means resonance self-shielding effect (implicit effect) is neglected. Furthermore, the multi-group covariance data is generated from the continuous-energy cross sections. Therefore, in order to perform S&U analysis with respect to the continuous-energy cross sections for both accuracy and consistency, a hybrid method is proposed in this paper. The subgroup-parameter sensitivity-coefficients are calculated based on the direct perturbation (DP) method. The sensitivity-coefficients of the effective self-shielding cross sections and the responses (k_eff and few-group homogenized cross sections) are calculated based on the generalized perturbation theory (GPT). A boiling water reactor (BWR) pin-cell problem under different power conditions is calculated and analyzed. The numerical results reveal that the proposed hybrid method improves the sensitivity-coefficients of eigenvalue and few-group homogenized cross sections. The temperature effects on the sensitivity-coefficients are demonstrated and the uncertainties are analyzed.