Some applications of fuzzy logic in rule–based expert systems

Fuzzy logic has been used as a means of interpreting vague, incomplete and even contradictory information into a compromised rule base in artificial intelligence such as machine decision–making. Within this context, fuzzy logic can be applied in the field of expert systems to provide additional flexibilities in constructing a working rule base: different experts' opinions can be incorporated into the same rule base, and each opinion can be modeled in a rather vague notion of human language. As some illustrative application examples, this paper describes how fuzzy logic can be used in expert systems. More precisely, it demonstrates the following applications: (i) a healthcare diagnostic system, (ii) an autofocus camera lens system and (iii) a financial decision system. For each application, basic rules are described, the calculation method is outlined and numerical simulation is provided. These applications demonstrate the suitability and performance of fuzzy logic in expert systems.     

基于直觉模糊逻辑的近似推理方法

针对直觉模糊逻辑及命题演算,提出了利用隶属度和犹豫度计算直觉模糊逻辑命题真值的合成方法．给出了直觉模糊逻辑命题的运算规则,重点研究了基于直觉模糊逻辑的近似推理方法．该方法包括直觉模糊取式推理,直觉模糊拒武推理及直觉模糊假官推理．井推导了相关的推理合成运算公式．以具体算例验证和表明了所提出的推导方法的正确性和有效性,以及对方法进行验证的详细步骤．     

一种基于模糊聚类的模糊本体生成方法

本文研究了一种从模糊背景生成模糊本体的方法。模糊本体由以下几部分组成,分别是：模糊形式概念分析、模糊概念聚类及模糊本体生成。首先,模糊形式概念分析将模糊逻辑嵌入形式概念分析以构成模糊概念格。其次,模糊概念聚类从模糊概念格构造概念层次。最后,模糊本体生成部分从概念层次生成模糊本体。     

Interactive Fuzzy Interval Reasoning for smart Web shopping

In this paper, we propose an Interactive Fuzzy Interval Reasoning (FIR) method by combining fuzzy logic with interval computing to better serve Web users in terms of effectiveness and flexibility. Web users may use convenient interval inputs for online shopping. In order to serve different customers based on their preferences, different personalized fuzzy partitions to meet different needs are provided for the different Web customers. The Interactive Fuzzy Interval Reasoning method is used to design the Web shopping agent. Java servlets and Microsoft Access are used to implement the fuzzy Web shopping system.     

Interval type-2 fuzzy logic and modular neural networks for face recognition applications

In this paper we present a method for response integration in multi-net neural systems using interval type-2 fuzzy logic and fuzzy integrals, with the purpose of improving the performance in the solution of problems with a great volume of information. The method can be generalized for pattern recognition and prediction problems, but in this work we show the implementation and tests of the method applied to the face recognition problem using modular neural networks. In the application we use two interval type-2 fuzzy inference systems (IT2-FIS); the first IT2-FIS was used for feature extraction in the training data, and the second one to estimate the relevance of the modules in the multi-net system. Fuzzy logic is shown to be a tool that can help improve the results of a neural system by facilitating the representation of human perceptions.     

Genetic-based fuzzy models: Interest rate forecasting problem

Many phenomena in our lives are difficult to predict. Especially financial markets have eluded successful prediction attempts. Interest rates are quite volatile and nonlinear. We develop the system capable of processing Korean financial data and modeling time-series processes (such as interest rate) with fuzzy logic and genetic algorithms(GAs). In this paper, we bring together two technologies: fuzzy theory and genetic algorithms. The combination of these techniques could be applied to the interest rate forecasting problem in Korean financial market. The fuzzy rules can be concisely represented with one or more FAM (Fuzzy Associative Memory) matrices. We use GAs to adapt the FAM matrix entries so that the interest rate forecasting problem leads to an improved performance. This paper presents the Genetic-Based Fuzzy Model (GBFM).     

Systematic design of a stable type-2 fuzzy logic controller

Stability is one of the more important aspects in the traditional knowledge of automatic control. Type-2 fuzzy logic is an emerging and promising area for achieving intelligent control (in this case, fuzzy control). In this work we use the fuzzy Lyapunov synthesis as proposed by Margaliot and Langholz [M. Margaliot, G. Langholz, New Approaches to Fuzzy Modeling and Control: Design and Analysis, World Scientific, Singapore, 2000] to build a Lyapunov stable type-1 fuzzy logic control system, and then we make an extension from a type-1 to a type-2 fuzzy logic control system, ensuring the stability on the control system and proving the robustness of the corresponding fuzzy controller.     

数据库中的模糊逻辑规则发现

关联规则是数据库中的知识发现（KDD）领域的重要研究课题。模糊关联规则可以用自然语言来表达人类知识,近年来受到KDD研究人员的普遍关注。但是,目前大多数模糊关联规则发现方法仍然沿用经典关联规则发现中常用的支持度和置信度测度。事实上,模糊关联规则可以有不同的解释,而且不同的解释对规则发现方法有很大影响。从逻辑的观点出发,定义了模糊逻辑规则、支持度、蕴含度及其相关概念,提出了模糊逻辑规则发现算法,该算法结合了模糊逻辑概念和Apriori算法,从给定的定量数据库中发现模糊逻辑规则。     

心电图的智能识别技术

模糊逻辑、神经网络是人工智能的重要分支,它们从不同角度、在一定程度上模拟了人类智能。本文先后将模糊逻辑、神经网络以及模糊神经网络技术用于心电图识别,获得了良好的效果。在模糊识别方面,从模糊识别矩阵的建立到模糊输入向量的确定,是针对此类具体问题的多传感器模糊信息融合算法,既综合考虑了各输入变量的作用,又突出了识别的主要依据。本文还给出了神经网络识别的三种试验结果及其与模糊神经网络识别的对比。模糊神经网络既充分发挥了神经网络的学习功能,又充分发挥了模糊逻辑的推理功能,因此具有很高的识别精度。     

Integrated Fuzzy–HMH for project uncertainties in time–cost tradeoff problem

Time–cost tradeoff (TCT) problem in project scheduling studies how to schedule project activities to achieve a tradeoff between project cost and project completion time. It gives project planners both challenges and opportunities to work out the best plan that optimizes time and cost to complete a project. In this paper, we present a novel method which examines the effects of project uncertainties on both, the duration as well as the cost of the activities. This method integrates a fuzzy logic framework with Hybrid Meta-Heuristic. Hybrid Meta-Heuristic (HMH) is an innovative approach which hybridizes a multiobjective genetic algorithm and simulated annealing. Integration of HMH and fuzzy logic is referred to as ‘integrated Fuzzy–HMH’. A rule based fuzzy logic framework brings up changes in the duration and the cost of each activity for the input uncertainties and HMH searches for Pareto-optimal front (TCT profile) for a given set of time–cost pair of each project activity. Two standard test problems from the literature are attempted using HMH. A case study of TCT problem is solved using integrated Fuzzy–HMH. The method solves time–cost tradeoff problems within an uncertain environment and carries out its sensitivity analysis.     

基于模糊命题逻辑形式系统FLcom的模糊推理及应用

FLcom是建立在模糊集FScom基础上的一种区分矛盾否定、对立否定和中介否定的模糊命题逻辑形式系统。在模糊推理中关于否定的认识和处理主要以经典逻辑为基础,为此在FLcom基础上研究了区分3种否定的模糊推理规则的表示,给出了基于FLcom的模糊推理规则的合成算法FLMP和FLMT规则,新算法推广了CRI算法中的蕴涵算子,并给出了模糊推理应用的实例对比。结果表明FLcom在区分不同否定的实际应用中是合理可行的。     

一种模糊逻辑系统的快速学习算法

本文提出了一种模糊逻辑系统的快速学习算法．算法要求预先确定各输入变量上模 糊集合的数目及分布;模糊规则前件可以是任意形状的模糊集合,后件则必须采用单值模糊 集合;模糊推理采用乘积推理;解模糊方法采用Tsukamoto方法．算法由输入－输出数据对 提取模糊规则．模糊规则的后件采用最小二乘方法一次计算得出．本算法对目标对象的逼近 精度取决于输入参数上模糊集合的数目,数目越多,精度越高．算法所需计算量小．     

A Fuzzy Inference Network Model for Search Strategy Using Neural Logic Network

In this paper, a fuzzy inference network model for search strategy using neural logic network is presented. The model describes search strategy, and neural logic network is used to search. Fuzzy logic can bring about appropriate inference results by ignoring some information in the reasoning process. Neural logic networks are powerful tools for the reasoning process but not appropriate for the logical reasoning. To model human knowledge, besides the reasoning process capability, the logical reasoning capability is equally important. Another new neural network called neural logic network is able to do the logical reasoning. Because the fuzzy inference is a fuzzy logical reasoning, we construct a fuzzy inference network model based on the neural logic network, extending the existing rule inference network. And the traditional propagation rule is modified.     

基于模糊逻辑的智能股票投资模型

模糊数学已经被大量地应用于工业控制,本文根据证券市场上投资者的思维过程与模糊逻辑的相似性,尝试把模糊学引入股票市场投机行为的控制,模拟股票市场上投资者的股票买卖行为,旨在探索一种基于模糊逻辑的自动股票投机和投资逻辑,可以为股票软件开发提供理论依据和逻辑模型,建立在模糊逻辑基础上的股票软件可以引导投资者避免追涨杀跌,从而有利于股市稳定而健康地发展.     

无损检测中基于模糊逻辑的多传感器数据融合

模糊逻辑在多传感器数据融合中得到广泛的应用，但是基于模糊逻辑的多传感器数据融合在无损检测中的应用还是一个崭新的课题，本文给出了一种新的用于无损检测数据融合的模糊逻辑结构，并且给出了隶度函数以及运算符的定义，最后给出了例子阐明了这种结构在无损检测中的应用。     

一种基于PFLC的可演化模糊逻辑控制器设计与实现

常规的模糊控制器主要通过计算机软件或单片机实现,但模糊控制器是一个高度并行的系统,实时性、自适应性要求较高,这种实现方式不能满足现代模糊控制器的设计要求。要解决这个问题必须从算法和器件结构入手。本文提出以可编程模糊逻辑控制器芯片（PFLC）作为可演化的部件,利用遗传算法优化生成模糊规则的演化硬件结构。模糊规则的自适应性是通过引入可调整因子,根据环境的变化自寻优获得。以典型二阶系统模糊控制为例进行仿真实验,其结果表明了这个可演化的模糊逻辑控制器结构的可行性。     

模糊逻辑控制器的模糊神经网络实现

模糊逻辑是人脑思维活动的基本方式，而神经网络则是模仿人脑神经系统功能而设计的一类巨型非线性网络。所以将模糊逻辑与神经网络相结合具有很大的前途。本文利用模糊神经元突破了没有计算机就不能实现模糊控制的传统观点，给出了一种不用计算机就能实现的模糊神经网络控制器，对模糊控制的硬件实现起到积极的作用。     

归结与调解方法的有效性和完备性--基于扩充模糊逻辑

模糊集与模糊逻辑是处理大量存在的不确定性与模糊性信息的重要数学工具,在近似推理等领域有着广泛的应用。该文将王家兵等人提出的真值取在[0,1]区间上的带有相似性关系的模糊逻辑,扩充到很一般的与滋可比的有余完全分配格值逻辑中,将王家兵等人的许多结论进行了推广。首先对带有相似性关系的模糊逻辑的语义描述进行了扩充,然后讨论了在这种模糊推理中归结式与调解式的有效性,最后通过证明一个子句集在扩充模糊逻辑中的不可满足性与它在带有相等关系的二值逻辑中的不可满足性是等价的,得到了基于归结与调解方法对这种广义模糊演算的完备性。     

一类具有3种否定的模糊模态命题逻辑

对不同否定知识的认知、区分、表达、推理及计算是模糊知识研究处理的一个基础。具有矛盾否定、对立否定和中介否定的模糊命题逻辑形式系统FLCOM是一种能够完整描述模糊知识中的不同否定及其关系与规律的理论。基于FLCOM和中介模态命题逻辑MK,提出一类具有3种否定的模糊模态命题逻辑MKCOM及其扩充系统MTCOM,MS₄COM和MS₅COM;讨论了MKCOM的语义和语法解释,并证明了MKCOM的可靠性定理和完备性定理。     

Some properties of fuzzy reasoning in propositional fuzzy logic systems

In order to analyze the logical foundation of fuzzy reasoning, this paper first introduces the concept of generalized roots of theories in ?ukasiewicz propositional fuzzy logic ?uk, Gödel propositional fuzzy logic Göd, Product propositional fuzzy logic Π, and nilpotent minimum logic NM (the R₀-propositional fuzzy logic L^∗). Next, it is proved that all consequences of a theory Γ, named D(Γ), are completely determined by its generalized root whenever Γ has a generalized root. Moreover, it is proved that every finite theory Γ has a generalized root, which can be expressed by a specific formula. Finally, we demonstrate the existence of a non-fuzzy version of Fuzzy Modus Ponens (FMP) in ?uk, Göd, Π and NM (L^∗), and we provide its numerical version as a new algorithm for solving FMP.