An improved fitting method for subgroup parameters based on the heterogeneous cells

An accurate subgroup parameters fitting method, where background cross sections obtained based on heterogeneous cells are used to fit the subgroup level and subgroup weight, is proposed in this paper. Due to the dependence of background cross section on the subgroup level, the calculation of the subgroup parameters is a nonlinear problem, which causes the iteration between fitting subgroup parameters and updating background cross sections. The cubic spline interpolation method is used to update the background cross sections to avoid frequently solving fixed source equations. In the fitting process, the negative subgroup parameters are often obtained, and the accuracy of the subgroup parameters is very sensitive to the iterative initial values of subgroup levels. To avoid these problems, additional constraints ensuring positive subgroup parameters and guaranteeing numerical stability are added to the optimization function. Penalty function method is used to convert the optimization problem with constraints into the one without constraints, making the problem easy to be solved. The proposed method is tested against the problems of pin cell, pressurized water reactor assemblies and plate-type assembly. The numerical results show that the self-shielded cross sections calculated by the proposed method agree well with those by Monte Carlo code.     

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.     

对称框架同构类的计数——处理复杂系统的新思维系列之八

本系列论文基于《多边矩阵理论》，由东方整体性思维所启迪，试图提供并完善一套从整体到局部处理复杂系统多指标问题、非均匀性问题、非线性问题的强有力的数学工具，并对其进行严格的理论推导和证明。对称性或对称分析方法，是众多学科关注的问题之一，我们认为构造对称框架是研究对称性问题的基础。本文利用框架的特征来构造稳定子群，再利用稳定子群得到商集，从而得到对称框架；并提出对称框架同构类的个数的计算公式；这种方法对对称分析的研究具有重要意义。     

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。     

双目标流水线调度的动态双子群离散果蝇算法

提出了一种基于动态双子群的离散果蝇优化算法,求解以最大完工时间和机床空闲时间的最小化为目标的无等待流水线调度问题。与传统的果蝇算法不同,该算法采用基于工序的编码方式,并用改进的NEH方法进行初始化,提高初始解的质量;根据算法在进化过程中个体的进化水平,动态地将整个群体划分为先进子群和后进子群,简单但有效地插入方法在先进个体邻域内进化精细搜索,贪婪迭代进化机制用于优化后进个体,以此平衡算法的全局开发能力和局部搜索能力;为了提高算法效率,快速算法用于计算函数目标值和判断更新非支配解。仿真试验表明了所提果蝇算法的有效性和高效性。     

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.     

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。     

Comparing meta-analytic moderator estimation techniques under realistic conditions.

One of the most problematic issues in contemporary meta-analysis is the estimation and interpretation of moderating effects. Monte Carlo analyses are developed in this article that compare bivariate correlations, ordinary least squares and weighted least squares (WLS) multiple regression, and hierarchical subgroup (HS) analysis for assessing the influence of continuous moderators under conditions of multicollinearity and skewed distribution of study sample sizes (heteroscedasticity). The results show that only WLS is largely unaffected by multicollinearity and heteroscedasticity, whereas the other techniques are substantially weakened. Of note, HS, one of the most popular methods, typically provides the most inaccurate results, whereas WLS, one of the least popular methods, typically provides the most accurate results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lattice structure on some fuzzy algebraic systems

In this paper, we study the lattice structure of some fuzzy algebraic systems such as (G-)fuzzy groups, some fuzzy ordered algebras and fuzzy hyperstructures. We prove that under suitable conditions, these structures form a distributive or modular lattice. This research partially is supported by the “ Fuzzy Systems and its Applications Center of Excelence, Shahid Bahonar University of Kerman, Iran”.     

关于极大子群的指数复合

利用Deskins在1959年所定义的有限群的极大子群的指数复合,得到关于群的可解性和超可解性一些新的刻划.主要结果如下:(1)假设F′G＝{M:M为G的包含某Sylow子群正规化子的极大子群,且|G∶M|为合数},则下列命题是等价的:(i)G是可解的;(ii)对于每个M∈F′G,存在一个极大完备C,使得对于任意x∈G,CxM,并且C/K(C)幂零.(iii)对于每个M∈F′G,存在一个极大完备C,使得C/K(C)或可换,或者满足G=CM,且C/K(C)的阶无平方因子.(2)有限群G是超可解的当且仅当对于每个M∈F′G,存在一个极大完备C,使得G=CM且C/K(C)的阶无平方因子.