The implementation of quality function deployment based on linguistic data

Quality function deployment (QFD) is a customer-driven quality management and product development system for achieving higher customer satisfaction. The QFD process involves various inputs in the form of linguistic data, e.g., human perception, judgment, and evaluation on importance or relationship strength. Such data are usually ambiguous and uncertain. An aim of this paper is to examine the implementation of QFD under a fuzzy environment and to develop corresponding procedures to deal with the fuzzy data. It presented a process model using linguistic variables, fuzzy arithmetic, and defuzzification techniques. Based on an example, this paper further examined the sensitivity of the ranking of technical characteristics to the defuzzification strategy and the degree of fuzziness of fuzzy numbers. Results indicated that selection of the defuzzification strategy and membership function are important. This proposed fuzzy approach allows QFD users to avoid subjective and arbitrary quantification of linguistic data. The paper also presents a scheme to represent and interprete the results.     

Unsatisfying functions and multiobjective fuzzy satisfaction design using genetic algorithms

This paper describes a new fuzzy satisfaction method using genetic algorithms (GA) for multiobjective problems. First, an unsatisfying function, which has a one-to-one correspondence with the membership function, is introduced for expressing "fuzziness". Next, the multiobjective design problem is transformed into a satisfaction problem of constraints by introducing an aspiration level for each objective. Here, in order to handle the fuzziness involved in aspiration levels and constraints, the unsatisfying function is used, and the problem is formulated as a multiobjective minimization problem of unsatisfaction ratings. Then, a GA is employed to solve the problem, and a new strategy is proposed to obtain a group of Pareto-optimal solutions in which the decision maker (DM) is interested. The DM can then seek a satisfaction solution by modifying parameters interactively according to preferences.     

Improved batch fuzzy learning vector quantization for image compression

In this paper, we develop a batch fuzzy learning vector quantization algorithm that attempts to solve certain problems related to the implementation of fuzzy clustering in image compression. The algorithm’s structure encompasses two basic components. First, a modified objective function of the fuzzy c-means method is reformulated and then is minimized by means of an iterative gradient-descent procedure. Second, the overall training procedure is equipped with a systematic strategy for the transition from fuzzy mode, where each training vector is assigned to more than one codebook vectors, to crisp mode, where each training vector is assigned to only one codebook vector. The algorithm is fast and easy to implement. Finally, the simulation results show that the method is efficient and appears to be insensitive to the selection of the fuzziness parameter.     

新的模糊粗糙集的模糊性度量方法

研究了模糊粗糙集的模糊性度量方法。首先从模糊集支集的角度,给出了一般模糊关系下模糊集的粗糙隶属函数;在此基础上,设计了一种合理的模糊粗糙集的模糊性度量方法,并对其相关性质进行了详细的讨论。     

基于项目模糊相似度的协同过滤推荐算法

针对传统协同过滤算法中评分和标签存在的模糊性问题进行了研究,利用梯形模糊数描述评分与满意度的映射关系,在考虑评分稀疏性的基础上构建了一种新的梯形模糊评分模型以判断基于模糊评分的相似度,分析标签与项目的隶属度,构建模糊项目标签矩阵以衡量基于标签隶属度的相似度,最终采用改进的评分预测策略进行评分估计。在MovieLens数据集上的实验结果显示,所提算法在抑制项目冷启动、缓解模糊性和稀疏性问题的同时,提高了预测精度,表明了该算法的有效性。     

模糊环境下的最小权顶点覆盖问题*

最小权顶点覆盖问题在实际决策中应用广泛,但顶点上的权值在实际应用中通常代表费用、成本等,在很多情况下是不确定的。关注了最小权顶点覆盖问题中的模糊不确定性,对模糊环境下的最小权顶点覆盖问题进行了研究。引入了可信性理论以描述模糊不确定性,并根据不同的决策准则建立了求解模糊环境下最小权顶点覆盖问题的三个决策模型,结合模糊模拟和遗传算法设计了一种求解所建立模型的混合智能算法,并给出了数值实验。数值实验的结果验证了所提出的决策模型与算法的有效性。     

Study on solution models and methods for the fuzzy assignment problems

In this study, commercing from the structural characteristics of fuzzy information, we propose the concept of level effect function, which can be used to describe fuzziness consciousness and to establish an I_L-metric method to measure all aspects of fuzzy information; further, we present an uncertainty metric model of concentrated quantification value; then, we establish two kinds of solution models based on the synthesizing effect of fuzzy assignment problems, by combining the genetic algorithm and assignment problems, and describe a concrete implementation strategy and algorithm to fuzzy assignment problem (denoted by GA⊕SE-FAM, for short); finally, we consider the algorithm’s convergence using Markov chain theory, and analyze its performance through simulation of practical examples. All of these indicate that this algorithm possesses the advantages of higher feasibility and easier operationalization, as such, it can be widely used in many fuzzy assignment problems.     

基于上下文感知的网络选择切换策略

针对异构无线网络环境中如何动态选网的问题,提出了一种基于上下文感知的网络选择切换策略。该策略提出一个动态的网络感知解决方案,引入模糊逻辑切换判决,以某项选择指标为依据过滤掉不满足需求的接入网络,并设计一种网络得分函数对网络进行排名计算。仿真实验表明,所提的切换策略可以为用户选择适合的接入网络,实验资源的有效利用。     

一个基于三角函数的直觉模糊熵公式

利用三角函数定义了一个直觉模糊熵公式,该公式不仅考虑了直觉模糊集的隶属度与非隶属度的偏差,而且考虑了直觉模糊集的犹豫度.对以往文献给出的两个直觉模糊熵公式进行了讨论,并将所提出的公式与这两个公式进行了比较.算例分析表明,所提出的熵公式能够反映直觉模糊集的不确定性和未知性程度.     

基于模糊回归的质量屋决策模型

基于带有对称三角形模糊系数的模糊回归及模糊规划理论，提出关联函数及自 相关函数的数学模型，并在系统考虑资源约束影响的基础上，分别建立了基于质量屋的产品 规划精确模型及模糊模型．仿真研究表明，这些模型适合于各种工程设计问题，尤其是在不 确定的、模糊的条件下，能够有效地确定关联函数及自相关函数，帮助开发人员优化顾客需 求的满意水平，在资源约束下使产品的顾客满意度最大．     

Fuzzy rule interpolation based on the ratio of fuzziness of interval type-2 fuzzy sets

In recent years, some fuzzy rule interpolation methods have been presented for sparse fuzzy rule-based systems based on interval type-2 fuzzy sets. However, the existing methods have the drawbacks that they cannot guarantee the convexity of the fuzzy interpolated result and may generate the same fuzzy interpolated results with respect to different observations. Moreover, they also cannot deal with fuzzy rule interpolation with bell-shaped interval type-2 fuzzy sets. In this paper, we present a new method for fuzzy rule interpolation for sparse fuzzy rule-based systems based on the ratio of fuzziness of interval type-2 fuzzy sets. The proposed method can overcome the drawbacks of the existing methods. First, it calculates the weights of the closest fuzzy rules with respect to the observation to obtain an intermediate consequence fuzzy set. Then, it uses the ratio of fuzziness of interval type-2 fuzzy sets to infer the fuzzy interpolated result based on the intermediate consequence fuzzy set. We also use some examples to compare the fuzzy interpolated results of the proposed method with the results by the existing methods. The experimental results show that the proposed fuzzy rule interpolation method gets more reasonable results than the existing methods.     

虚拟驾驶环境中车辆智能体的驾驶行为模型

建立虚拟交通环境的多智能体结构,分析车辆智能体的驾驶行为分层模型以及感知、决策和操作等过程。采用模糊专家系统建立车辆智能体的驾驶行为模型。为模拟现实中的驾驶员行为特性,加入驾驶员因子,使驾驶模拟器的虚拟交通环境更符合现实。运用OpenGVS产生和显示实时交互的虚拟驾驶场景。结果表明该模型能体现实际驾驶行为的多样性、随机性和模糊性。该模型通用有效,它使驾驶模拟器的虚拟交通场景更真实满意。     

Applying weakest t-norm based approximate intuitionistic fuzzy arithmetic operations on different types of intuitionistic fuzzy numbers to evaluate reliability of PCBA fault

This research addresses system reliability analysis using weakest t-norm based approximate intuitionistic fuzzy arithmetic operations, where failure probabilities of all components are represented by different types of intuitionistic fuzzy numbers. Due to the incomplete, imprecise, vague and conflicting information about the component of system, the present study evaluates the reliability of system in terms of membership function and non-membership function by using weakest t-norm (T_w) based approximate intuitionistic fuzzy arithmetic operations on different types of intuitionistic fuzzy numbers. In general, interval arithmetic (α-cut arithmetic) operations have been used to analyze the fuzzy system reliability. In complicated systems, interval arithmetic operations may occur the accumulating phenomenon of fuzziness. In order to overcome the accumulating phenomenon of fuzziness, this research adopts approximate intuitionistic fuzzy arithmetic operations under the weakest t-norm arithmetic operations (T_w) to analyze fuzzy system reliability. The approximate intuitionistic fuzzy arithmetic operations employ principle of interval arithmetic under the weakest t-norm arithmetic operations. The proposed novel fuzzy arithmetic operations may obtain fitter decision values, which have smaller fuzziness accumulating and successfully analyze the system reliability. Also weakest t-norm arithmetic operations provide more exact fuzzy results and effectively reduce fuzzy spreads (fuzzy intervals). Using proposed approach, fuzzy reliability of series system and parallel system are also constructed. For numerical verification of proposed approach, a malfunction of printed circuit board assembly (PCBA) is presented as a numerical example. The result of the proposed method is compared with the listing approaches of reliability analysis methods.     

/spl alpha/-cut fuzzy arithmetic: simplifying rules and a fuzzy function optimization with a decision variable

The problems of /spl alpha/-cut fuzzy arithmetic have been shown, like in interval arithmetic, that distinct states of fuzzy parameters (or fuzzy variable values) may be chosen and produce an overestimated fuzziness. Meanwhile, local extrema of a function may exist inside the support of fuzzy parameters and cause an underestimation of fuzziness and an illegal fuzzy number's result. Previous approaches to overcoming these problems have appeared in literature. Yet, the computational burden of these approaches became even heavier. Thus, this paper is based on the vertex method in literature and extensively proposes newly devised rules observed greatly useful for simplifying the vertex method. These rules are devised through a function partitioned into subfunctions, distinguishing the types of fuzzy parameter/variable occurrences, and types of subfunctions or functions with the various observations. The improved efficiency has been found able to significantly reduce the combination (vertex) test of the vertex method for the fuzzy parameters' /spl alpha/-cut endpoints possibly to only a few fuzzy parameters' endpoint combinations. Also as related, a procedure for the fuzzy optimization of fuzzy functions with a fuzzy blurred argument (a single variable) is examined with the vertex method as well. A proper and useful preliminary algorithm is proposed. Numerical examples with results are provided.     

Type-2 Fuzzy Markov Random Fields and Their Application to Handwritten Chinese Character Recognition

In this paper, we integrate type-2 (T2) fuzzy sets with Markov random fields (MRFs) referred to as T2 FMRFs, which may handle both fuzziness and randomness in the structural pattern representation. On the one hand, the T2 membership function (MF) has a 3-D structure in which the primary MF describes randomness and the secondary MF evaluates the fuzziness of the primary MF. On the other hand, MRFs can represent patterns statistical-structurally in terms of neighborhood system and clique potentials and, thus, have been widely applied to image analysis and computer vision. In the proposed T2 FMRFs, we define the same neighborhood system as that in classical MRFs. To describe uncertain structural information in patterns, we derive the fuzzy likelihood clique potentials from T2 fuzzy Gaussian mixture models. The fuzzy prior clique potentials are penalties for the mismatched structures based on prior knowledge. Because Chinese characters have hierarchical structures, we use T2 FMRFs to model character structures in the handwritten Chinese character recognition system. The overall recognition rate is 99.07%, which confirms the effectiveness of the proposed method.     

An improved medical image enhancement scheme using Type II fuzzy set

A contrast enhancement of medical images using Type II fuzzy set theory is suggested. Fuzzy set theory considers uncertainty in the form of membership function but to have better information on uncertainty on the membership function, Type II fuzzy set is considered. Type II fuzzy set considers fuzziness in the membership function. Hamacher T co norm is used as an aggregation operator to form a new membership function using the upper and lower membership function of Type II fuzzy set. The image with the new membership function is an enhanced image. As medical images contain lot of uncertainties, Type II fuzzy set may be a good tool for medical image analysis. To show the effectiveness of the proposed method, the results are compared with fuzzy, intuitionistic fuzzy, and existing Type II fuzzy methods. Experiments on several images show that the proposed Type II fuzzy method performs better than the existing methods. To show the advantage of the proposed enhancement method, detection or extraction of abnormal lesions or blood vessels has been carried out on enhanced images of all the methods. It is observed that the segmented results on the proposed enhanced images are better.     

Incorporating human learning into a fuzzy EOQ inventory model with backorders

Even though publications on fuzzy inventory problems are constantly increasing, modelling the decision maker’s characteristics and their effect on his/her decisions and consequently on the planning outcome has not attracted much attention in the literature. In order to fill this research gap and model reality more accurately, this paper develops a new fuzzy EOQ inventory model with backorders that considers human learning over the planning horizon. The paper is an extension of an existing EOQ inventory model with backorders in which both demand and lead times are fuzzified. Here, the assumption of constant fuzziness is relaxed by incorporating the concept of learning in fuzziness into the model considering that the degree of fuzziness reduces over the planning horizon. The proposed fuzzy EOQ inventory model with backorders and learning in fuzziness has a good performance in efficiency. Finally, it is worth mentioning that learning in fuzziness decreases the total inventory cost.     

基于模糊模式识别的巴布剂均匀度检测系统

为实现对巴布剂涂布过程中均匀度的检测,提出一种基于模糊模式识别的检测方法。根据采集图像像素点之间的空间和时间相关性及其特征界限的模糊性,引入模糊集理论,运用模糊算法对像素点的灰度值进行识别分类。检测系统采用基于CycloneⅡ系列的FPGA技术,运用Verilog HDL硬件语言对系统完成建模与实现,并且通过了仿真和验证。通过在线测试,对视频数据流进行分析、处理和识别,实现对涂布过程中巴布剂均匀度的检测,根据统计结果,正确率达到95%。检测结果证明了模糊模式识别算法的可行性和检测系统的可靠性。     

Parallel fuzzy inference based on α-level sets and generalized means

In this paper, a parallel fuzzy-inference method is proposed in which inference consequences are unified on the basis of α-level sets and generalized means. It has the following advantages over conventional methods: (1) it can control the degree to which the fuzziness and specificity of given facts are reflected to those of unified inference consequences, (2) it can deduce unified inference consequences in the form of normal and convex fuzzy sets which can thus be treated as fuzzy numbers, and (3) it effectively matches systems that include fuzzy-set operations based on the extension principle. This paper first reviews the generalized mean and describes the computational steps of the proposed inference method. Then, the properties of this method are investigated, and the control mechanism of the fuzziness and specificity in unified inference consequences, reflecting those in given facts, are presented. The efficient inference computations are also provided, taking advantage of the α-level-set-based scheme of the proposed inference method. Next, a learning algorithm is derived for the proposed inference method based on the error back-propagation. By feeding fuzzy exemplar patterns, it can automatically adjust the above-mentioned degree of fuzziness and specificity as well as the fuzzy sets in conditional propositions. The simulation studies show the feasibility of the proposed inference method.     

基于分解协调的空间分布系统的模糊控制

为解决多控制源空间分布系统的控制问题,在以往文献提出的空间模糊控制器的基础上,提出一种基于空间分解、局部协调的空间模糊控制策略,针对多控制源设计了具有协调功能的空间模糊控制器.以三区快速加热化学气相沉积反应器系统为例,对所提出的控制方法进行了仿真验证.仿真结果表明,该方法能取得更好的空间均匀性.