三参数区间数下基于映射的可拓区间简单关联函数决策分析方法北大核心CSCD

针对属性值为三参数区数的多属性决策问题,文章提出了一种新的基于可拓区间简单关联度的多属性决策方法和框架.该方法定义了可拓三参数区间简单关联函数表达式,同时集成了区间计算和态度函数,并通过映射函数使得简单关联函数具备非线性的表达能力.由于态度函数能够较精确地反映决策者对各评价值的倾向态度,该方法通过态度函数的设置进行决策的不确定性分析,还能用可拓移动变换对决策进行动态性分析和规则发现.最后,通过算例分析说明了该方法的合理性和稳定性.     

三参数区间数下基于映射的可拓区间简单关联函数决策分析方法

针对属性值为三参数区数的多属性决策问题,文章提出了一种新的基于可拓区间简单关联度的多属性决策方法和框架.该方法定义了可拓三参数区间简单关联函数表达式,同时集成了区间计算和态度函数,并通过映射函数使得简单关联函数具备非线性的表达能力.由于态度函数能够较精确地反映决策者对各评价值的倾向态度,该方法通过态度函数的设置进行决策的不确定性分析,还能用可拓移动变换对决策进行动态性分析和规则发现.最后,通过算例分析说明了该方法的合理性和稳定性.     

一元关联函数的可拓变换及其在昆虫种群生态学中的应用

本文依据一元关联函数的基本概念和初等关联函数的可拓变换定义 ,首次将关联函数的可拓变换应用于豆田天敌蝽类的生态研究 ,为控制害虫发生 ,更好地保护维持生态平衡的重要天敌类群提供理论根据 .     

山体隧道结构安全模糊可拓评估模型

为完善山体隧道结构安全评价方法,提高运营期保障可靠度.首先在分析隧道结构固有属性和动态影响因素的基础上,构建了能够全面反映山体隧道结构安全的评价指标体系,并对不同等级下指标值进行无量纲化处理.其次将区间模糊数与可拓理论相结合提出山体隧道结构安全评价模型,关联度由不确定型可拓初等关联函数确定,指标权重由区间模糊熵权法求解,并采用集结算子进行综合评价.最后,以霞浦洋坪隧道为例,按照模型步骤对其结构安全进行了系统评价,同时与其它已有方法进行了对比分析.研究成果不仅丰富山体隧道安全评价模型,也为交通部门决策提供了参考.     

多评价特征基元可拓集研究

在单评价特征基元可拓集的基础上,研究多评价特征基元可拓集的构造方法及其关联函数的建立方法,为多特征综合评价和多特征不相容问题求解提供理论依据和可操作的形式化、定量化方法,使多特征不相容问题的智能化处理成为可能.     

基于可拓集合的动态分类及其UML表示方法研究

可拓集合是分析事物的可变性和多变性的理论基础 .本文首先建立了物元与类之间的联系 ,在可拓集合零界的基础上建立了过渡类 ,为了形式化描述出多值分类 ,对关联函数进行约束 ,并利用可拓域与物元变换探讨了动态分类机制 ,最后采用 UML构造型扩展机制对动态分类的表示问题进行初步的研究 .     

解决矛盾问题的可拓模型与可拓知识的研究

可拓学是解决矛盾问题的学科,在可拓学的可拓模型原型的基础上,明确了计算机解决矛盾问题的可拓模型,它包括三部分:关联函数、可拓知识和推理算法,其中关联函数和可拓知识对不同的问题需要利用不同的原理,且它们是逐步变化的.在可拓知识中,关联函数的可拓变换需要通过计算证明其值是逐步增加的.这样,矛盾问题在计算机中才能得到解决.本文通过多个实例来说明解决矛盾问题的可拓模型及可拓知识的建立和实现.     

基于映射理论下的决策评判模型

按照映射理论,通过建立评价指标标准值与评价指标标准值顺序数之间的函数,将非等长度区间映射成长度为1的等长区间,提出了一种求解决策评判的新模型,解决了不同标度下的评价因子、评价类别的决策评判问题,纠正了可拓理论关联函数基本公式的错误,简化了可变模糊集模型中的M矩阵和B矩阵,进而统一了可拓评价和可变模糊集理论在决策评判中的一致性,并实例验证了模型的优越性和正确性,对决策评判问题具有重要的应用拓广参考价值.     

有限区间内四阶样条小波的构造

用有限区间上的截断4阶B样条,构造了有限区间上的4阶样条小波。这些小波由边界小波和内部小波组成,对某一尺度,它们组成了有限维的小波空间。于是,任何有限区间上的函数皆可表示为该区间上的尺度函数和小波函数的有限和,即小波级数,这克服了用无穷区间上的小波进行有限信号处理时,在边界上误差较大的不足,同时将该小波用于偏微分方程具有同样重要的意义。     

可拓学中关联函数的构造及零界的确定

可拓学的核心是通过可拓变换使矛盾问题转化,而其定量化工具之一是关联函数,针对某些工程计算盲目套用关联函数问题和零界概念的误解,指出了错误所在并予以纠正.     

基于集对分析联系数的区间数型多属性决策投影模型及其在基坑支护方案评价中的应用

多属性决策时因掌握的信息有限,加之问题本身的复杂性、不确定性以及人类思维的模糊性,其属性的精确值往往难以获取,常用区间数形式表示针对多属性决策中各指标区间数不能直接进行大小比较的问题,提出一种基于集对分析联系数的区间数型多属性决策投影模型.模型用备择方案在理想方案上的投影进行集结,根据区间数的误差分布形式,沟通区间数与联系数的关系,根据a+bi型联系数大小比较法则,综合评价方案优劣.以某大厦基坑支护拟用的4种方案优化选择为例,说明方法的应用与模糊优化理论模型和灰色物元分析优化模型进行了对比,得到的结果一致.     

基于区间数贴近度的不确定多属性决策模型

针对只有部分权重信息且属性值以区间数形式给出的多属性决策问题,提出了一种基于区间数贴近度的决策方法.首先讨论了区间数贴近度的定义和性质;然后给出了解决不确定多属性决策问题的一般步骤.并依据传统的逼近理想解的基本思路,以实际评价值与理想解之间的贴近度最大化为目标建立优化模型,从而得到指标权重.进而计算出每个方案与正理想解的相对贴近度,即可得到所有方案的排序结果.方法能充分利用规范化评价的先验信息,评价结果客观可靠,不具有主观随意性.最后通过实例分析验证了该方法的有效性和实用性.     

On the extension problem for continuous positive definite Generalized Toeplitz Kernels definite on a finite interval

The extension problem for positive definite Generalized Toeplitz Kernels defined on a finite interval of the real axis is discussed. This problems contains the Krein's extension problem for a positive definite function as a particular case. Criteria of uniqueness of extension is obtained. All extension are described in a complitely indeterminate case.     

On the decision problem for theories of finite models

An infinite extension of the elementary theory of Abelian groups is constructed, which is proved to be decidable, while the elementary theory of its finite models is shown to be undecidable. Tarski’s proof of undecidability for the elementary theory of Abelian cancellation semigroups is presented in detail. Szmielew’s proof of the decidability of the elementary theory of Abelian groups is used to prove the decidability of the elementary theory of finite Abelian groups, and an axiom system for this theory is exhibited. It follows that the elementary theory of Abelian cancellation semigroups, while undecidable, has a decidable theory of finite models.     

风险型混合多属性消错决策方法

针对同时包含可线性补偿和不可线性补偿两种属性且属性值为确实数、区间数、语言信息的风险型多属性决策问题,提出一种基于消错理论的决策方法。首先,在消错理论的基础上将属性分为关键型、重要型和冗余型三类,结合属性值的类型分别给出对应的错误函数和极限损失值;接着,对关键型属性赋予极小权重,在保留关键型属性“一票否决”功能的同时又突出重要属性的作用;最后,根据对待错误损失的不同态度,建立计算错误损失值的三种方法,通过计算期望错误损失值对备选方案进行排序。通过新市民信息服务项目的例子,说明该方法的有效性和可行性。     

Initial boundary value problems for nonlinear dispersive wave equations

In this paper we study initial value boundary problems of two types of nonlinear dispersive wave equations on the half-line and on a finite interval subject to homogeneous Dirichlet boundary conditions. We first prove local well-posedness of the rod equation and of the b-equation for general initial data. Furthermore, we are able to specify conditions on the initial data which on the one hand guarantee global existence and on the other hand produce solutions with a finite life span. In the case of finite time singularities we are able to describe the precise blow-up scenario of breaking waves. Our approach is based on sharp extension results for functions on the half-line or on a finite interval and several symmetry preserving properties of the equations under discussion.     

Function field genus theory for non-Kummer extensions

In this paper we first obtain the genus field of a finite abelian non-Kummer l–extension of a global rational function field. Then, using that the genus field of a composite of two abelian extensions of a global rational function field with relatively prime degrees is equal to the composite of their respective genus fields and our previous results, we deduce the general expression of the genus field of a finite abelian extension of a global rational function field.     

An Extension of Generalized Linear Models to Finite Mixture Outcome Distributions

Finite mixture distributions arise in sampling a heterogeneous population. Data drawn from such a population will exhibit extra variability relative to any single subpopulation. Statistical models based on finite mixtures can assist in the analysis of categorical and count outcomes when standard generalized linear models (GLMs) cannot adequately express variability observed in the data. We propose an extension of GLMs where the response follows a finite mixture distribution and the regression of interest is linked to the mixture’s mean. This approach may be preferred over a finite mixture of regressions when the population mean is of interest; here, only one regression must be specified and interpreted in the analysis. A technical challenge is that the mixture’s mean is a composite parameter that does not appear explicitly in the density. The proposed model maintains its link to the regression through a certain random effects structure and is completely likelihood-based. We consider typical GLM cases where means are either real-valued, constrained to be positive, or constrained to be on the unit interval. The resulting model is applied to two example datasets through Bayesian analysis. Supporting the extra variation is seen to improve residual plots and produce widened prediction intervals reflecting the uncertainty. Supplementary materials for this article are available online.     

Why is quantum physics based on complex numbers?

The modern quantum theory is based on the assumption that quantum states are represented by elements of a complex Hilbert space. It is expected that in future quantum theory the number field will not be postulated but derived from more general principles. We consider the choice of the number field in a quantum theory based on a finite field. We assume that the symmetry algebra is the finite field analog of the de Sitter algebra so(1,4) and consider spinless irreducible representations of this algebra. It is shown that the finite field analog of complex numbers is the minimal extension of the residue field modulo p for which the representations are fully decomposable.     

A construction of real closed fields

We introduce a new construction of real closed fields by using an elementary extension of an ordered field with an integer part satisfying . This method can be extend to a finite extension of an ordered field with an integer part satisfying . In general, a field obtained from our construction is either real closed or algebraically closed, so an analogy of Ostrowski's dichotomy holds. Moreover we investigate recursive saturation of an o‐minimal extension of a real closed field by finitely many function symbols.