一种模糊逻辑推理神经网络的结构及算法设计

建立了一种基于模糊逻辑推理的神经网络．由样本获取的初始规则确定规则层神经元个数,并确立模糊化层与规则层之间的连接．利用黄金分割法确定模糊化层隶属度函数的初始中心和宽度;根据初始规则的结论确定清晰化层的初始权值;针对网络结构提出了改进的BP算法．仿真实例表明,网络结构合理。具有较好的非线性映射能力,改进的BP算法适合于此网络,与另一种模糊神经网络相比较具有较快的训练速度和较好的泛化能力．     

A fuzzy neural network with fuzzy impact grades

Fuzzy rule derivation is often difficult and time-consuming, and requires expert knowledge. This creates a common bottleneck in fuzzy system design. In order to solve this problem, many fuzzy systems that automatically generate fuzzy rules from numerical data have been proposed. In this paper, we propose a fuzzy neural network based on mutual subsethood (MSBFNN) and its fuzzy rule identification algorithms. In our approach, fuzzy rules are described by different fuzzy sets. For each fuzzy set representing a fuzzy rule, the universe of discourse is defined as the summation of weighted membership grades of input linguistic terms that associate with the given fuzzy rule. In this manner, MSBFNN fully considers the contribution of input variables to the joint firing strength of fuzzy rules. Afterwards, the proposed fuzzy neural network quantifies the impacts of fuzzy rules on the consequent parts by fuzzy connections based on mutual subsethood. Furthermore, to enhance the knowledge representation and interpretation of the rules, a linear transformation from consequent parts to output is incorporated into MSBFNN so that higher accuracy can be achieved. In the parameter identification phase, the backpropagation algorithm is employed, and proper linear transformation is also determined dynamically. To demonstrate the capability of the MSBFNN, simulations in different areas including classification, regression and time series prediction are conducted. The proposed MSBFNN shows encouraging performance when benchmarked against other models.     

Fuzzy feature selection

In fuzzy classifier systems the classification is obtained by a number of fuzzy If–Then rules including linguistic terms such as Low and High that fuzzify each feature. This paper presents a method by which a reduced linguistic (fuzzy) set of a labeled multi-dimensional data set can be identified automatically. After the projection of the original data set onto a fuzzy space, the optimal subset of fuzzy features is determined using conventional search techniques. The applicability of this method has been demonstrated by reducing the number of features used for the classification of four real-world data sets. This method can also be used to generate an initial rule set for a fuzzy neural network.     

基于TS模糊神经网络的Fuzzy规则自动获取研究

Fuzzy规则的获取一直是模糊智能系统的一个瓶颈。醉在深入研究TS模糊神经网络的物理意义的基础上,给出了使用遗传算法优化模糊规则集的算法并提出了从训练后的TS模糊神经网络中抽取Fuzzy规则的可操作方法。分析和实验证明,这种方法可以实现且是有效的,对于Fuzzy规则自动获取的研究具有积极的借鉴意义。     

正负模糊规则系统、极限学习机与图像分类

传统的图像分类一般只利用了图像的正规则,忽略了负规则在图像分类中的作用。Nguyen将负规则引入图像分类,提出将正负模糊规则相结合形成正负模糊规则系统,并将其用于遥感图像和自然图像的分类。实验证明,其在图像分类过程中取得了很好的效果。他们提出的前馈神经网络模型在调整权值时利用了梯度下降法,由于步长选择不合理或陷入局部最优从而使训练速度受到了限制。极限学习机（ELM）是一种单隐层前馈神经网络（SLFN）学习算法,具有学习速度快,泛化性能好的优点。本文证明了极限学习机与正负模糊规则系统的实质是等价的,遂将其用于图像分类。实验结果说明了极限学习机能很好的利用正负模糊规则相结合的方法对图像进行分类,实验结果较为理想。     

A neural fuzzy system with fuzzy supervised learning

A neural fuzzy system learning with fuzzy training data (fuzzy if-then rules) is proposed in this paper. This system is able to process and learn numerical information as well as linguistic information. At first, we propose a five-layered neural network for the connectionist realization of a fuzzy inference system. The connectionist structure can house fuzzy logic rules and membership functions for fuzzy inference. We use alpha-level sets of fuzzy numbers to represent linguistic information. The inputs, outputs, and weights of the proposed network can be fuzzy numbers of any shape. Furthermore, they can be hybrid of fuzzy numbers and numerical numbers through the use of fuzzy singletons. Based on interval arithmetics, a fuzzy supervised learning algorithm is developed for the proposed system. It extends the normal supervised learning techniques to the learning problems where only linguistic teaching signals are available. The fuzzy supervised learning scheme can train the proposed system with desired fuzzy input-output pairs which are fuzzy numbers instead of the normal numerical values. With fuzzy supervised learning, the proposed system can be used for rule base concentration to reduce the number of rules in a fuzzy rule base. Simulation results are presented to illustrate the performance and applicability of the proposed system.     

基于T-S模糊模型的神经网络的系统辨识

基于T-S模糊模型,提出了利用神经网络实现非线性系统的辨识。首先,利用一种无监督的聚类算法分析输入输出数据生成初始的结构模型,确定系统的模糊空间和模糊规则数,构造神经网络辨识模型前提参数,使前提参数自适应变化,有较好的自学习能力和优化能力,采用最小二乘法取得结论参数。仿真结果验证了该方法是有效和可行的。     

一种改进型T-S模糊神经网络

对T-S模糊神经网络进行了分析,提出了一种新型T-S模糊神经网络,改进了前件网络的结构及学习算法,减少了模糊规则层的节点数,有效地克服了T-S模糊神经网络模糊规则冗余的缺点。这种新型T-S模糊神经网络具有学习算法简单、收敛速度快等优点。把该网络应用到卷取温度控制中进行仿真,得到了满意的结果。     

一种基于聚类的超闭球模糊神经网络

针对一类不确定非线性多输入多输出复杂系统,根据系统的输入输出数据对,提出一种基于聚类的超闭球模糊神经网络系统．该系统通过改进的模糊聚类方法（FCM）确定模糊规则数,采用高维隶属度函数取代常规的单维隶属度函数,并对隶属度函数中心值和隶属度函数参数采用一步通过算法,所提方法可降低系统的模糊规则数,简化网络计算．此外,当系统的输入输出发生变化时,可实现模糊规则库的在线修改．仿真实例验证了所提方法的有效性．     

The construction of a fuzzy inference network by extension of the rule inference network

Fuzzy logic can bring about inappropriate inferences as a result of ignoring some information in the reasoning process. Neural networks are powerful tools for pattern processing, but are not appropriate for the logical reasoning needed to model human knowledge. The use of a neural logic network derived from a modified neural network, however, makes logical reasoning possible. In this paper, we construct a fuzzy inference network by extending the rule–inference network based on an existing neural logic network. The propagation rule used in the existing rule–inference network is modified and applied. In order to determine the belief value of a proposition pertaining to the execution part of the fuzzy rules in a fuzzy inference network, the nodes connected to the proposition to be inferenced should be searched for. The search costs are compared and evaluated through application of sequential and priority searches for all the connected nodes.     

Adaptive fuzzy inference neural network

An adaptive fuzzy inference neural network (AFINN) is proposed in this paper. It has self-construction ability, parameter estimation ability and rule extraction ability. The structure of AFINN is formed by the following four phases: (1) initial rule creation, (2) selection of important input elements, (3) identification of the network structure and (4) parameter estimation using LMS (least-mean square) algorithm. When the number of input dimension is large, the conventional fuzzy systems often cannot handle the task correctly because the degree of each rule becomes too small. AFINN solves such a problem by modification of the learning and inference algorithm.     

An accuracy-oriented self-splitting fuzzy classifier with support vector learning in high-order expanded consequent space

This paper proposes a self-splitting fuzzy classifier with support vector learning in expanded high-order consequent space (SFC-SVHC) for classification accuracy improvement. The SFC-SVHC expands the rule-mapped consequent space of a first-order Takagi-Sugeno (TS)-type fuzzy system by including high-order terms to enhance the rule discrimination capability. A novel structure and parameter learning approach is proposed to construct the SFC-SVHC. For structure learning, a variance-based self-splitting clustering (VSSC) algorithm is used to determine distributions of the fuzzy sets in the input space. There are no rules in the SFC-SVHC initially. The VSSC algorithm generates a new cluster by splitting an existing cluster into two according to a predefined cluster-variance criterion. The SFC-SVHC uses trigonometric functions to expand the rule-mapped first-order consequent space to a higher-dimensional space. For parameter optimization in the expanded rule-mapped consequent space, a support vector machine is employed to endow the SFC-SVHC with high generalization ability. Experimental results on several classification benchmark problems show that the SFC-SVHC achieves good classification results with a small number of rules. Comparisons with different classifiers demonstrate the superiority of the SFC-SVHC in classification accuracy.     

基于EKF 的自组织T-S 模糊Elman 网络

针对模糊神经网络结构设计问题及模糊集在语言描述上存在的不足, 提出一种基于扩展的卡尔曼滤波(EKF)的自组织T-S 模糊Elman 网络, 并推导了网络训练算法. 分别采用递归最小二乘法和EKF 对线性参数和非线性参数进行更新; 基于模糊规则生成准则和误差下降率修剪策略实现了模糊规则的增删减. 最后通过系统辨识和污水处理建模实验, 表明了该算法在保证网络精度和泛化能力的同时, 可以有效地简化网络结构.

     

A new method for fuzzy information retrieval based on fuzzy hierarchical clustering and fuzzy inference techniques

In this paper, we extend the work of Kraft et al. to present a new method for fuzzy information retrieval based on fuzzy hierarchical clustering and fuzzy inference techniques. First, we present a fuzzy agglomerative hierarchical clustering algorithm for clustering documents and to get the document cluster centers of document clusters. Then, we present a method to construct fuzzy logic rules based on the document clusters and their document cluster centers. Finally, we apply the constructed fuzzy logic rules to modify the user's query for query expansion and to guide the information retrieval system to retrieve documents relevant to the user's request. The fuzzy logic rules can represent three kinds of fuzzy relationships (i.e., fuzzy positive association relationship, fuzzy specialization relationship and fuzzy generalization relationship) between index terms. The proposed fuzzy information retrieval method is more flexible and more intelligent than the existing methods due to the fact that it can expand users' queries for fuzzy information retrieval in a more effective manner.     

Multiprocessor Task Assignment with Fuzzy Hopfield Neural Network Clustering Technique

Most scheduling applications have been demonstrated as NP-complete problems. A variety of schemes are introduced in solving those scheduling applications, such as linear programming, neural networks, and fuzzy logic. In this paper, a new approach of first analogising a scheduling problem to a clustering problem and then using a fuzzy Hopfield neural network clustering technique to solve the scheduling problem is proposed. This fuzzy Hopfield neural network algorithm integrates fuzzy c-means clustering strategies into a Hopfield neural network. This investigation utilises this new approach to demonstrate the feasibility of resolving a multiprocessor scheduling problem with no process migration and constrained times (execution time and deadline). Each process is regarded as a data sample, and every processor is taken as a cluster. Simulation results illustrate that imposing the fuzzy Hopfield neural network onto the proposed energy function provides an appropriate approach to solving this class of scheduling problem.       

Fuzzy neural networks for estimation and fuzzy controller design: simulation study for a pulp batch digester

A structural implementation of a fuzzy inference system through connectionist network based on MLP with logical neurons connected through binary and numerical weights is considered. The resulting fuzzy neural network is trained using classical backpropagation to learn the rules of inference of a fuzzy system, by adjustment of the numerical weights. For controller design, training is carried out off line in a closed loop simulation. Rules for the fuzzy logic controller are extracted from the network by interpreting the consequence weights as measure of confidence of the underlying rule. The framework is used in a simulation study for estimation and control of a pulp batch digester. The controlled variable, the Kappa number, a measure of lignin content in the pulp, which is not measurable is estimated through temperature and liquor concentration using the fuzzy neural network. On the other hand a fuzzy neural network is trained to control the Kappa number and rules are extracted from the trained network to construct a fuzzy logic controller.     

模糊竞争神经网络在线辨识及在CSTR中的应用

基于改进的T-S模糊模型构造了一种自适应模糊竞争神经网络模型(FCNN),给出了网络的连接结构和学习算法。它依据模糊竞争学习算法确定系统的模糊空间和模糊规则数,得出每个样本对每条规则的适用程度,并利用卡尔曼滤波算法在线辨识FCNN的后件参数。将其应用于化工过程连续搅拌反应器(CSTR)的建模中,仿真结果表明,FCNN具有结构简洁、收敛速度快、辨识精度高等特点,可当作复杂系统建模的一种有效手段。     

An stable online clustering fuzzy neural network for nonlinear system identification

In this paper, we propose a online clustering fuzzy neural network. The proposed neural fuzzy network uses the online clustering to train the structure, the gradient to train the parameters of the hidden layer, and the Kalman filter algorithm to train the parameters of the output layer. In our algorithm, learning structure and parameter learning are updated at the same time, we do not make difference in structure learning and parameter learning. The center of each rule is updated to obtain the center is near to the incoming data in each iteration. In this way, it does not need to generate a new rule in each iteration, i.e., it neither generates many rules nor need to prune the rules. We prove the stability of the algorithm.     

A fuzzy modeling method via Enhanced Objective Cluster Analysis for designing TSK model

This paper proposes a fuzzy modeling method via Enhanced Objective Cluster Analysis to obtain the compact and robust approximate TSK fuzzy model. In our approach, the Objective Cluster Analysis algorithm is introduced. In order to obtain more compact and more robust fuzzy rule prototypes, this algorithm is enhanced by introducing the Relative Dissimilarity Measure and the new consistency criterion to represent the similarity degree between the clusters. By these additional criteria, the redundant clusters caused by iterations are avoided; the subjective influence from human judgment for clustering is weakened. Moreover the clustering results including the number of clusters and the cluster centers are considered as the initial condition of the premise parameters identification. Thus the traditional iteration modeling procedure for determining the number of rules and identifying parameters is changed into one-off modeling, which significantly reduces the burden of computation. Furthermore the decomposition errors and the approximation errors resulted from premise parameters identification by Fuzzy c-Means clustering are decreased. For the consequence parameters identification, the Stable Kalman Filter algorithm is adopted. The performance of the proposed modeling method is evaluated by the example of Box–Jenkins gas furnace. The simulation results demonstrate the power of our model.     

FRBF: A Fuzzy Radial Basis Function Network

The FRBF network is designed by integrating the principles of a radial basis function network and the fuzzy c-means algorithm. The architecture of the network is suitably modified at the hidden layer to realise a novel neural implementation of the fuzzy clustering algorithm. Fuzzy set-theoretic concepts are incorporated at the input, output and hidden layers, enabling the model to handle both linguistic and numeric inputs, and providing a soft output decision. The effectiveness of the model is demonstrated on a speech recognition problem.