基于T-S推理网络的油田开发指标预测方法*

针对油田开发指标预测问题,提出一种T-S推理元模型,该模型包括输入层、模糊化层和推理层。每个推理元对应一条模糊逻辑规则,由若干T-S推理元可构成T-S推理网络。网络可调参数包括模糊集参数和模糊规则参数。提出了基于改进量子粒子群优化的参数确定方法。以油田开发指标中含水率和采油量预测为例,结果表明,该方法是有效且可行的,从而表明模糊逻辑与智能优化算法的融合对于解决指标预测问题具有一定潜力。     

基于T-S模型和PQGA的油田指标预测方法

针对油田开发指标预测问题,提出一种T-S模型建模方法.该方法采用量子遗传算法优化T-S参数.首先根据预测指标及影响因素建立模糊规则库,然后根据模糊规则库建立T-S预测模型,采用改进的量子遗传算法优化T-S参数.以油田开发指标中含水率预测为例,结果表明该方法是有效可行的.     

一种模糊CMAC神经网络

提出了一种模糊CMAC(小脑模型关节控制器)神经网络,它由输入层、模糊化层、模糊相 联层、模糊后相联层与输出层等5层节点组成,具有与CMAC相似的单层连接权,可通过BP 算法学习推论参数或模糊规则.给出了网络的连接结构与学习算法,并将其应用于函数逼近 问题中仿真结果验证了该方法较之CMAC的优越性.     

基于有效性分析的自组织模糊神经网络建模方法

提出了一种基于有效性分析的自组织模糊神经网络(self-organizingfuzzyneural network based on effectiveness analysis, SOEFNN)建模方法。首先,提出了一种针对模糊规则的有效性评价指标,利用样本与规则层输出之间的映射关系进行网络模型的有效性分析,通过累积触发的方式实现相应模糊规则的增加或删减,使网络模型在能够处理复杂非线性问题的同时降低其冗余性,使模型更为紧凑。采用梯度下降算法对网络模型进行训练。然后,对所提出的SOEFNN模型进行非线性系统仿真实验和污水处理过程中的出水生化需氧量预测建模,并与其他自组织模糊神经网络模型进行对比。仿真结果表明,所提出的SOEFNN模型能够很好地实现结构和参数的自适应调整,并且具有较好的逼近能力。     

模糊关联规则挖掘在电力负荷预测中的应用

提出了一种基于模糊关联规则挖掘的电力负荷预测新方法，采用模糊C-均值算法对连续型属性域上的历史数据进行分类并模糊化，应用文中提出的模糊关联规则挖掘算法挖掘出电力负荷量与其相关环境变量间潜在的有效模糊关联规则。利用这些规则进行匹配预测，得到电力负荷量模糊化的预测结果；最后将其反模糊化，得出预测值。给出了实验仿真结果，表明了该方法的有效性。     

基于改进模糊神经网络的软测量建模方法

提出了一种改进的模糊神经网络软测量建模方法，采用规则化的平均输出隶属度函数作为模糊基函数进行反模糊化运算；在训练网络时,部分参数采用Levenberg-Marquardt算法来训练，另一部分采用一阶梯度下降法．最后用该建模方法建立了聚合反应中熔融指数的软测量模型，并与一般的模糊神经网络软测量模型进行比较．结果表明改进的模糊神经网络对初始值的选择不敏感,具有很好的收敛性，同时还能达到指定的预测精度，很适合工程应用．     

一种加权模糊推理网络模型及其应用

提出了一种加权模糊推理网络的结构模型和学习算法,该网络的基本信息处理单元为模糊推理神经元,融合了模糊逻辑能够较完整地表达领域规则和先验知识,以及神经网络自适应环境的优点。根据模糊推理规则的量化表示形式和微分方程数值解的动力学思想推导出了该网络模型的学习算法。该算法具有稳定、收敛速度快,且能较好地避免网络学习陷入局部极值点。以油田生产复杂水淹层识别问题为例,验证了模型和算法的有效性。     

一种自适应模糊CMAC控制器

本文提出一种自适应模糊ＣＭＡＣ控制器的设计方法，该控制器由模糊ＣＭＡＣ神经网络的五层节点实现模糊控制的输入，模糊化，模糊逻辑运算，归一化及输出值准确化运算，并由合适的ＢＰ训练算法修改相应的权系数，实现模糊控制规则的调整。     

模糊神经网络在非线性短期负荷预测中的应用

为提高负荷预测精度,提出了一种新的4层模糊神经网络短期负荷预测模型.该模型将模糊逻辑和神经网络的长处融合在一起,使模糊推理和解模糊均通过神经网络来实现.选取的隶属函数使神经网络权值有一定的知识表示意义,并通过模糊化层将输入特征量转化为模糊量.在模糊推理层提出了两种不同的算法来完成模糊推理,然后从中确定出模糊取小算法预测效果更好.最后在输出层通过适当的解模糊得到确切的预测输出值.仿真结果表明了该方法的有效性.     

加权模糊推理网络及在水淹层识别中的应用

提出了一种加权模糊推理网络的结构模型和学习算法，该网络的基本信息处理单元为模糊推理神经元，融合了模糊逻辑能够较完整的表达领域规则和先验知识以及神经网络自适应环境的优点。根据模糊推理规则的量化表示形式和微分方程数值解的动力学思想推导出网络一种新的学习算法。该算法具有稳定，收敛速度快，且能较好避免网络学习陷入局部极值点。以油田生产复杂水淹层识别问题为例，验证了模型和算法的有效性。     

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 high speed railway control system based on the fuzzy control method

This paper proposed a high-speed railway control system based on the fuzzy control method. The fuzzy control system of the high-speed railway is designed in the Matlab software according to the expert experience and knowledge. At first the input and output variables have been fuzzified in the fuzzification process. Then the membership function is designed and the control rules are discussed in detail bring into correspondence with expert knowledge. The parameters discussion about the maximum speed and traction effort are studied in detail. Finally, the defuzzify process can output the results directly to control the high speed railway train. The results indicated that the fuzzy control system is effective and accurate in the high speed railway control process.     

基于模糊理论的pH值控制系统设计及应用

本文通过阐述模糊PID控制器精确量的模糊化、规则库的建立以及产生模糊推理,结合锌冶炼沉铁工艺过程pH调节出现的问题,提出了在西门子控制系统基础上应用SCL语言建立模糊PID控制器。用模糊控制理论将pH值的偏差和pH值的偏差变化作为输入变量,以输出增量作为输出语言变量,实践表明,通过该方法建立的模糊控制器具有很强的鲁棒性和可靠性。     

A high-order fuzzy time series forecasting model for internet stock trading

Recently, many fuzzy time series models have already been used to solve nonlinear and complexity issues. However, first-order fuzzy time series models have proven to be insufficient for solving these problems. For this reason, many researchers proposed high-order fuzzy time series models and focused on three main issues: fuzzification, fuzzy logical relationships, and defuzzification. This paper presents a novel high-order fuzzy time series model which overcomes the drawback mentioned above. First, it uses entropy-based partitioning to more accurately define the linguistic intervals in the fuzzification procedure. Second, it applies an artificial neural network to compute the complicated fuzzy logical relationships. Third, it uses the adaptive expectation model to adjust the forecasting during the defuzzification procedure. To evaluate the proposed model, we used datasets from both the Taiwanese stock index from 2000 to 2003 and from the student enrollment records of the University of Alabama. The results of our study show that the proposed model is able to obtain an accurate forecast without encountering conventional fuzzy time series issues.     

Handling forecasting problems based on fuzzy time series model and model error learning

Classical fuzzy time series forecasts are comprised of three steps: fuzzification, identification of fuzzy relation, and defuzzification. In this paper, we propose a new approach and add an error learning step to improve forecasts. In the fuzzification step, a hybrid method, based on the fuzzy c-means clustering and the fuzzy Silhouette criterion, is employed to determine the optimal number of intervals, which avoids time-consuming iterations of the whole algorithm. In the defuzzification step, an optimization model is set up to explain the rule of defuzzification. In the model structure, an error term is assembled into the traditional model to express model error, which is predicted by linear fitting and abnormal errors processing. Learning of model errors and considering of data characteristics guarantee good interpretability and accuracy. The numerical results show that the proposed approach has superior forecast performance to existing methods.     

An improved fuzzy neural network based on T–S model

An improved fuzzy neural network based on Takagi–Sugeno (T–S) model is proposed in this paper. According to characteristics of samples spatial distribution the number of linguistic values of every input and the means and deviations of corresponding membership functions are determined. So the reasonable fuzzy space partition is got. Further a subtractive clustering algorithm is used to derive cluster centers from samples. With the parameters of linguistic values the cluster centers are fuzzified to get a more concise rule set with importance for every rule. Thus redundant rules in the fuzzy space are deleted. Then antecedent parts of all rules determine how a fuzzification layer and an inference layer connect. Next, weights of the defuzzification layer are initialized by a least square algorithm. After the network is built, a hybrid method combining a gradient descent algorithm and a least square algorithm is applied to tune the parameters in it. Simultaneous, an adaptive learning rate which is identified from input-state stability theory is adopted to insure stability of the network. The improved T–S fuzzy neural network (ITSFNN) has a compact structure, high training speed, good simulation precision, and generalization ability. To evaluate the performance of the ITSFNN, we experiment with two nonlinear examples. A comparative analysis reveals the proposed T–S fuzzy neural network exhibits a higher accuracy and better generalization ability than ordinary T–S fuzzy neural network. Finally, it is applied to predict markup percent of the construction bidding system and has a better prediction capability in comparison to some previous models.     

基于自相关函数的模糊时间序列优化算法

针对模糊时间序列模型中模糊推理规则的优化问题, 提出一种时间序列的自相关理论与模糊时间序列相结合的算法. 首先考查数据平稳化; 然后运用传统的数据模糊化方法得到模糊集, 进而建立模糊规则, 并运用自相关函数理论对模糊规则进行优化; 最后通过对Alabama 大学注册人数的预测验证了所提出算法的有效性.

     

神经模糊系统中模糊规则的优选

提出一种基于两级聚类算法的自组织神经模糊系统，该系统采用两级聚类算法（改进的最近邻域聚类算法和Gustafson-Kessel模糊聚类算法）对输入／输出数据进行模糊聚类，并由模糊聚类的划分熵确定最优划分，建立模糊模型，模型精度可由梯度下降法进一步提高。仿真结果表明，这种神经模糊系统具有结构简单、规则数少、学习速度快以及建模精度高等特点。     

模糊控制器输出值不变的两个充分条件

模糊控制器通常由模糊化、模糊推理以及清晰化三部分构成, 而模糊推理决定了一个由输入论域到输出论域的模糊映射. 当模糊映射为常值映射时, 任意选择模糊化和去模糊化方式, 模糊控制器的输出值不因输入信号变化而改变. 本文给出了模糊映射为常值映射的两个充分条件, 并将结论从单入单出模糊系统推广到多入单出模糊系统.