广义bent函数的性质与构造     

梅瑞 《成都航空职业技术学院学报》2013,29(3):24-26

广义bent函数f（x）对应的每个Walsh谱取值均相等,此时f（x）与仿射函数g（x）=x×y＋b（y∈ii,b∈Zq）的距离可证明都相等,这使得广义bent函数的非线性度达到最大。这种函数在保密和通信中有许多重要的应用。本文首先讨论了广义bent函数的一些性质,且通过这些性质在已有结论的基础上给出构造广义bent函数的一些方法,并在之后给出了证明。  相似文献   

采用非对称渐开线齿轮减少齿根应力的研究     

涂杰 《武汉职业技术学院学报》2013,12(1):97-99

为了减小齿轮的齿根弯曲应力,提高齿轮的传动能力,本文根据非对称渐开线齿轮研究学者提出的齿廓方程构建思路进行了建模,并用NISAⅡ进行了齿轮应力变化的有限元分析。通过分析比较得出使用非对称渐开线齿轮可以提高齿轮的弯曲强度从而提高齿轮的传动能力。  相似文献   

Confidence Intervals for a Semiparametric Approach to Modeling Nonlinear Relations among Latent Variables     

Jolynn Pek  Diane Losardo  Daniel J. Bauer 《Structural equation modeling》2013,20(4):537-553

Compared to parametric models, nonparametric and semiparametric approaches to modeling nonlinearity between latent variables have the advantage of recovering global relationships of unknown functional form. Bauer (2005) Bauer, D. J. 2005. A semiparametric approach to modeling nonlinear relations among latent variables. Structural Equation Modeling, 12: 513–535. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] proposed an indirect application of finite mixtures of structural equation models where latent components are estimated in the service of more flexibly recovering characteristics of the latent aggregate regression function. This article develops and evaluates delta method and parametric bootstrap approaches for obtaining approximate confidence intervals for Bauer's semiparametric approach to modeling latent nonlinear functions. Coverage rates of these approximate point-wise confidence intervals or nonsimultaneous confidence bands are evaluated by Monte Carlo and recommendations for their use are suggested.  相似文献   

Models and Strategies for Factor Mixture Analysis: An Example Concerning the Structure Underlying Psychological Disorders     

Shaunna L. Clark  Bengt Muthén  Jaakko Kaprio  Brian M. D'Onofrio  Richard Viken  Richard J. Rose 《Structural equation modeling》2013,20(4):681-703

The factor mixture model (FMM) uses a hybrid of both categorical and continuous latent variables. The FMM is a good model for the underlying structure of psychopathology because the use of both categorical and continuous latent variables allows the structure to be simultaneously categorical and dimensional. This is useful because both diagnostic class membership and the range of severity within and across diagnostic classes can be modeled concurrently. Although the conceptualization of the FMM has been explained in the literature, the use of the FMM is still not prevalent. One reason is that there is little research about how such models should be applied in practice and, once a well-fitting model is obtained, how it should be interpreted. In this article, the FMM is explored by studying a real data example on conduct disorder. By exploring this example, this article aims to explain the different formulations of the FMM, the various steps in building a FMM, and how to decide between an FMM and alternative models.  相似文献   

Modeling Nonlinear Structural Equation Models: A Comparison of the Two-Stage Generalized Additive Models and the Finite Mixture Structural Equation Model     

W. Holmes Finch 《Structural equation modeling》2013,20(1):60-75

Researchers have devoted some time and effort to developing methods for fitting nonlinear relationships among latent variables. In particular, most of these have focused on correctly modeling interactions between 2 exogenous latent variables, and quadratic relationships between exogenous and endogenous variables. All of these approaches require prespecification of the nonlinearity by the researcher, and are limited to fairly simple nonlinear relationships. Other work has been done using mixture structural equation models (SEMM) in an attempt to fit more complex nonlinear relationships. This study expands on this earlier work by introducing the 2-stage generalized additive model (2SGAM) approach for fitting regression splines in the context of structural equation models. The model is first described and then investigated through the use of simulated data, in which it was compared with the SEMM approach. Results demonstrate that the 2SGAM is an effective tool for fitting a variety of nonlinear relationships between latent variables, and can be easily and accurately extended to models including multiple latent variables. Implications of these results are discussed.  相似文献   

场路耦合有限元仿真在电机类课程教学中的应用研究     

陈小元  陈超 《丽水学院学报》2013,(2):49-53

利用JMAG-Studio软件建立永磁电机的场路耦合的有限元模型,计算并分析永磁电机的空载和负载时瞬态特性,直观地展示电机的电流、反电动势、磁通密度、转矩等性能,并制作成基于电机转子旋转的动画,帮助学生深入理解电机的基本概念和知识,提高电气自动化类专业的电机类课程的教学效果。  相似文献   

浮式海上风机平台设计及有限元分析     

李晨阳  张昱  张晓键  何炎平 《焦作大学学报》2013,(1):73-75

海上风能发电如今占能源供给的比例越来越高,随着其未来向深海的发展趋势,固定式风机将被浮式风机平台逐步取代。基于浮式风机平台的诸多优点,浮式风机平台的研究将对我国的海上风机平台发展产生重要的意义,而浮式风机平台的设计将进一步有助于研究浮式风机平台的性能。文章基于目前海上风机平台设计中出现的问题,从浪流和风力作用角度出发,运用力学原理,设计浮式海上风机平台,并对风机平台关键部分进行有限元分析,从而表明浮式海上风机平台设计方法的有效性和可行性。  相似文献   

温度影响下的橡胶沥青应力吸收层的应力分析     

蒋育红  李妍  尹硕  余修平 《马钢职工大学学报》2013,(1):51-54,57

高温开裂已经成为沥青路面的主要危害之一。橡胶沥青是良好的沥青改性剂,其具有吸收应力,改善沥青高温性能、延长路面使用寿命、延缓反射裂缝等优点。利用ABAQUS有限元软件,选取15℃、20％和60℃下沥青路面的热特性参数,分析在不同温度下橡胶沥青应力吸收层对半刚性基层路面结构和柔性基层路面结构的应力应变规律,推荐合理的沥青路面结构层设计参数,为工程实践提供理论依据。  相似文献   

有限群全形的计算     

王积社 《韩山师范学院学报》2013,(6):9-16

根据群的全形的定义及相关理论,设计出计算有限群全形的算法及程序,给出了剩余类加群全形的特殊算法及程序。  相似文献   

非标准有限差分法求解时滞抛物型方程     

刘明鼎  陈贵清  张艳敏  董保珠 《唐山学院学报》2013,(6):5-6,35

提出求解时滞抛物型方程的非标准有限差分法,其特点是在对微分方程中关于时间一阶导数项进行离散时,利用时间步长的函数φ（△t）代替分母△t,通过稳定性分析可以看出该格式是条件稳定的,数值算例表明该方法有很高的精度.  相似文献