Rough Set Models on Two universes

This paper focuses on rough set models on two universes and reveals some new properties. A revised rough set model is proposed which provides a new selection of interval structures for uncertain reasoning using rough set theory and methods.     

两个论域上的粗集结构

粗集理论是处理不精确和不确定的数据的工具,自Pawlak 提出了粗集理论后,粗集模型得到拓广,人们提出了许多新的粗集模型,在用特征函数的方法表示上下近似的基础上研究两个论域上的粗集结构。统一了粗集的各种推广模型,使得特征函数的方法与通常的集合论的方法形成互补,对粗集结构的简化及推理有帮助,可以加深对粗集结构的认识。     

双论域上粗糙集的矩阵定义

提出了两个关系矩阵的序偶取小乘法的概念,并利用关系矩阵和布尔列向量重量上乘法和下乘法的有关结论,给出了计算双论域上任一集合上下近似的具体算法,从而使得双论域上粗糙集的计算程序化。     

Possible black universes in a brane world

A black universe is a nonsingular black hole where, beyond the horizon, there is an expanding, asymptotically isotropic universe. Such spherically symmetric configurations have been recently found as solutions to the Einstein equations with phantom scalar fields (with negative kinetic energy) as sources of gravity. They have a Schwarzschild–like causal structure but a de Sitter infinity instead of a singularity. It is attempted to obtain similar configurations without phantoms, in the framework of an RS2 type brane world scenario, considering the modified Einstein equations that describe gravity on the brane. By building an explicit example, it is shown that black–universe solutions can be obtained there in the presence of a scalar field with positive kinetic energy and a nonzero potential.     

On contradiction in fuzzy logic

 We clarify which space of functions in [0, 1] ^E would be reasonable in fuzzy logic in order to avoid self-contradiction.     

Rough fuzzy approximations on two universes of discourse

In rough set theory, the lower and upper approximation operators can be constructed via a variety of approaches. Various fuzzy generalizations of rough approximation operators have been made over the years. This paper presents a framework for the study of rough fuzzy sets on two universes of discourse. By means of a binary relation between two universes of discourse, a covering and three relations are induced to a single universe of discourse. Based on the induced notions, four pairs of rough fuzzy approximation operators are proposed. These models guarantee that the approximating sets and the approximated sets are on the same universes of discourse. Furthermore, the relationship between the new approximation operators and the existing rough fuzzy approximation operators on two universes of discourse are scrutinized, and some interesting properties are investigated. Finally, the connections of these approximation operators are made, and conditions under which some of these approximation operators are equivalent are obtained.     

Fuzzy finite element analysis of imprecisely defined structures with fuzzy nodal force

This paper presents the fuzzy finite element analysis for static displacements of fixed free stepped rectangular beam, truss and simplified bridge structure with fuzzy nodal force. The material and geometric properties of the structures are taken as crisp. Fuzzy finite element analysis of static problem for the above structures converts the problem into fuzzy system of linear equations. As such the coefficient matrix and the right-hand side vector become crisp and fuzzy respectively. A new approach is used here to solve the fuzzy system of linear equations. Numerical results for the three stepped rectangular beam, three-bar truss and simplified bridge with fifteen elements are presented to illustrate the computational aspects of the developed method. The results obtained are depicted in term of plots.     

双论域粗糙集的矩阵表示

在双论域粗糙集中,不论是理论上还是应用上,矩阵方法都是一种简单且高效的计算方法。利用矩阵的方法来研究双论域粗糙集。提出了双论域上的关系矩阵,通过关系矩阵以及关系矩阵的转置,构造了两个布尔方阵。利用这两个布尔方阵的特征研究了双论域覆盖粗糙集的一些性质。定义了一种布尔矩阵之间新的运算,并且利用这个运算,简洁地表示了双论域覆盖粗糙集的上近似算子和关系粗糙集的下近似算子。     

Gravitational waves in singular and bouncing FLRW universes

We investigate propagation of gravitational waves in two models belonging to the Friedman-Lemaître-Robertson-Walker (FLRW) class of cosmologies: the singular Einstein-Maxwell Universe (EMU), which has an electromagnetic field described by Maxwell’s electrodynamics as the source of its geometry, and the bouncing Nonlinear Electrodynamics Universe (NLEU), which has the electromagnetic field described by a nonlinear generalization of Maxwell’s electrodynamics as the source of its geometry. We work with an explicitly gauge-independent formulation of cosmological perturbations in FLRW models and analyze the qualitative features of the dynamical system that describes the propagation of primordial tensorial perturbations in both geometries. Based on this analysis, we show that gravitational waves generated near a singularity or a bounce exhibit qualitatively different behavior.     

Analysis of families of hash functions defined by automata over a finite ring

Some general properties of families of hash functions defined by strongly connected automata without output function over a finite ring are analyzed. The probabilities of randomly choosing a sequence for which a hash function assumes a given value and also two different sequences of the same length for which the values of a hash function coincide. The computational security of the investigated hash-functions is characterized.     

Full hierarchical dependencies in fixed and undetermined universes

Full hierarchical dependencies (FHDs) constitute a large class of relational dependencies. A relation exhibits an FHD precisely when it is the natural join over at least two of its projections that all share the same join attributes. Therefore, FHDs generalise multivalued dependencies (MVDs) in which case the number of these projections is precisely two. The implication of FHDs has originally been defined in the context of some fixed finite universe. This paper identifies a sound and complete set of inference rules for the implication of FHDs. This axiomatisation is very reminiscent of that for MVDs. Then, an alternative notion of FHD implication is introduced in which the underlying set of attributes is left undetermined. The first main result establishes a finite axiomatisation for FHD implication in undetermined universes. It is then formally clarified that the complementation rule is only a mere means for database normalisation. In fact, the second main result establishes a finite axiomatisation for FHD implication in fixed universes which allows to infer FHDs either without using the complementation rule at all or only in the very last step of the inference. This also characterises the expressiveness of an incomplete set of inference rules in fixed universes. The results extend previous work on MVDs by Biskup.     

基于语义规则的中文矛盾关系识别方法

文本蕴涵是文本理解与语义推理的基础,近来在计算机语言领域受到了极大关注。矛盾关系是蕴涵关系的一种否定,二者都是语义学的主要研究内容。在文本蕴涵关系识别的基础之上,研究了如何识别文本矛盾关系,提出了一种基于语义规则的矛盾检测方法。实验表明,基于语义规则的矛盾检测方法对于中文矛盾关系识别是可行的,同时矛盾关系相对精确的识别也增强了文本蕴涵识别的准确性。     

双论域上的S-粗集及应用

原始从单论域出发讨论动态系统的知识发现和规则挖掘,其应用范围受到极大限制。通过构造性方法对原始的Ｓ-粗集粗糙集模型进行推广,提出双论域上的Ｓ-粗集模型。分析了S-粗集与Z.Pawlak 粗集、以及单论域Ｓ-粗集与双论域Ｓ-粗集的关系。并讨论了双论域Ｓ-粗集一些相关性质及在疾病诊断上的应用。     

基于关联规则的创新矛盾矩阵的研究

随着市场竞争不断加剧,企业创新成为现代企业生存的重要一环。首先,将用于解决技术性发明创造而建立的TRIZ理论引入到企业创新研究之中;通过计算机知识发现和数据挖掘技术与TRIZ理论中的矛盾思想相结合,并根据德国弗朗克协会提出的企业创新九个领域,将其细分为相应若干指标器;在此基础上,提出使用指标器间关联规则替代TRIZ创新原理。最后,使用这些关联性与九个创新领域,得到了一种适合描述企业创新的矛盾矩阵构成方法,为解决企业创新提供了分析依据。