A multi-objective decision-making model with fuzzy rough coefficients and its application to the inventory problem

In this paper, we concentrate on developing a fuzzy rough multi-objective decision-making model according to uncertainty theory. We present some equivalent models and a traditional algorithm based on an interactive fuzzy satisfying method, which is similar to the interactive fuzzy rough satisfying method, in order to obtain a satisfying solution for the decision maker. In addition, the technique of fuzzy rough simulation is applied to deal with general fuzzy rough objective functions and fuzzy rough constraints which are usually difficult to convert into their equivalents. Furthermore, combined with the techniques of fuzzy rough simulation, a genetic algorithm using the compromise approach is designed for solving a fuzzy rough multi-objective programming problem. Finally, a model is applied to an inventory problem to illustrate the usefulness of the proposed model and algorithm, and then a sensitivity analysis is made.     

Hypoglycaemia detection using fuzzy inference system with multi-objective double wavelet mutation Differential Evolution

In this paper, a fuzzy inference system (FIS) is developed to recognize hypoglycaemic episodes. Hypoglycaemia (low blood glucose level) is a common and serious side effect of insulin therapy for patients with diabetes. We measure some physiological parameters continuously to provide hypoglycaemia detection for Type 1 diabetes mellitus (TIDM) patients. The FIS captures the relationship between the inputs of heart rate (HR), corrected QT interval of the electrocardiogram (ECG) signal (QT_c), change of HR, change of QT_c and the output of hypoglycaemic episodes to perform the classification. An algorithm called Differential Evolution with Double Wavelet Mutation (DWM-DE) is introduced to optimize the FIS parameters that govern the membership functions and fuzzy rules. DWM-DE is an improved Differential Evolution algorithm that incorporates two wavelet-based operations to enhance the optimization performance. To prevent the phenomenon of overtraining (over-fitting), a validation approach is proposed. Moreover, in this problem, two targets of sensitivity and specificity should be met in order to achieve good performance. As a result, a multi-objective optimization using DWM-DE is introduced to perform the training of the FIS. Experiments using the data of 15 children with TIDM (569 data points) are studied. The data are randomly organized into a training set with 5 patients (l99 data points), a validation set with 5 patients (177 data points) and a testing set with 5 patients (193 data points). The result shows that the proposed FIS tuned by the multi-objective DWM-DE can offer good performance of doing classification.     

A hybrid model based on adaptive-network-based fuzzy inference system to forecast Taiwan stock market

In recent years, many academy researchers have proposed several forecasting models based on technical analysis to predict models such as Engle, 1982, Cheng et al., 2010. After reviewing the literature, two major drawbacks are found in past models: (1) the forecasting models based on artificial intelligence algorithms (AI), such as neural networks (NN) and genetic algorithms (GAs), produce complex and unintelligible rules; and (2) statistic forecasting models, such as time series, require some basic assumptions for variables and build forecasting models based on mathematic equations, which are not easily understandable by stock investors. In order to refine these drawbacks of past models, this paper has proposed a model, based on adaptive-network-based fuzzy inference system which uses multi-technical indicators, to predict stock price trends. Three refined processes have proposed in the hybrid model for forecasting: (1) select essential technical indicators from popular indicators by a correlation matrix; (2) use the subtractive clustering method to partition technical indicator value into linguistic values based on an data discretization method; (3) employ a fuzzy inference system (FIS) to extract rules of linguistic terms from the dataset of the technical indicators, and optimize the FIS parameters based on an adaptive network to produce forecasts. A six-year period of the TAIEX is employed as experimental database to evaluate the proposed model with a performance indicator, root mean squared error (RMSE). The experimental results have shown that the proposed model is superior to two listing models (Chen’s and Yu’s models).     

Performance assessment of a multi-objective parametric optimization algorithm with application to a multi-physical engineering system

The original problem of reliability-based design optimization (RBDO) is mathematically a nested two-level structure that is computationally time consuming for real engineering problems. In order to overcome the computational difficulties, many formulations have been proposed in the literature. These include SORA (sequential optimization and reliability assessment) that decouples the nested problems. SLA (single loop approach) further improves efficiency in that reliability analysis becomes an integrated part of the optimization problem. However, even SLA method can become computationally challenging for real engineering problems involving many reliability constraints. This paper presents an enhanced version of SLA where the first phase is based on approximation at nominal design point. After convergence of first iterative phase is reached the process transitions to a second phase where approximations of reliability constraints are carried out at their respective minimum performance target point (MPTP). The solution is implemented in Altair OptiStruct, where adaptive approximation and constraint screening strategies are utilized in the RBDO process. Examples show that the proposed two-phase approach leads to reduction in finite element analyses while preserving equal solution quality.     

基于改进型模糊聚类的模糊系统建模方法

结合减法聚类和模糊C均值聚类,提出了一种改进型聚类算法,加快了收敛速度．利用改进后的算法对模糊系统输入或输出的样本集聚类,对聚类结果采用Trust-Region法拟合高斯型和S型函数,以实现模糊系统输入、输出空间的划分和隶属度函数参数的确定．结合MATLAB的模糊和曲线拟合工具箱,详述了如何在标准算法上进行改进和模糊系统建模．通过对IRIS标准数据聚类实验以及在解决机械加工误差复映问题上的应用,验证了改进后算法和建模方法的有效性．     

基于模糊多目标的高超声速飞行器再入轨迹设计

针对多约束条件下的高超声速飞行器再入轨迹的优化问题,考虑多个具有不同重要性等级的优化指标,提出基于模糊多目标的轨迹设计方法.首先,利用直接配点法,将最优控制问题转化为带优先级的非线性多目标规划问题;然后,基于模糊满意优化的思想,根据更重要目标具有更高满意度的原则,将优先级表示为满意度序,并设计两步式优化模型.通过调节参数,能获得同时满足优化和重要性等级要求的最优轨迹.仿真结果表明了所提出方法的有效性.     

基于模糊推理的汽车辅助驾驶系统控制算法

在建立汽车辅助驾驶系统模型的基础上,指出满足驾驶员的驾驶特征是车辆控制的一个重要指标,此外针对驾驶员驾驶行为的不精确性,提出了以模糊推理为基础的上位控制方法,并对其进行了现场实验。实验结果表明,用模糊控制理论模拟驾驶行为的不精确性是可行的。通过模糊控制自车的速度,能够实现自车在多种工况下保持安全状态。     

A multi-objective dynamic vehicle routing problem with fuzzy time windows: Model,solution and application

In this paper, a multi-objective dynamic vehicle routing problem with fuzzy time windows (DVRPFTW) is presented. In this problem, unlike most of the work where all the data are known in advance, a set of real time requests arrives randomly over time and the dispatcher does not have any deterministic or probabilistic information on the location and size of them until they arrive. Moreover, this model involves routing vehicles according to customer-specific time windows, which are highly relevant to the customers’ satisfaction level. This preference information of customers can be represented as a convex fuzzy number with respect to the satisfaction for a service time. This paper uses a direct interpretation of the DVRPFTW as a multi-objective problem where the total required fleet size, overall total traveling distance and waiting time imposed on vehicles are minimized and the overall customers’ preferences for service is maximized. A solving strategy based on the genetic algorithm (GA) and three basic modules are proposed, in which the state of the system including information of vehicles and customers is checked in a management module each time. The strategy module tries to organize the information reported by the management module and construct an efficient structure for solving in the subsequent module. The performance of the proposed approach is evaluated in different steps on various test problems generalized from a set of static instances in the literature. In the first step, the performance of the proposed approach is checked in static conditions and then the other assumptions and developments are added gradually and changes are examined. The computational experiments on data sets illustrate the efficiency and effectiveness of the proposed approach.     

Sustainable supplier selection: A ranking model based on fuzzy inference system

In these days, considering the growth of knowledge about sustainability in enterprise, the sustainable supplier selection would be the central component in the management of a sustainable supply chain. In this paper the sustainable supplier selection criteria and sub-criteria are determined and based on those criteria and sub-criteria a methodology is proposed onto evaluation and ranking of a given set of suppliers. In the evaluation process, decision makers’ opinions on the importance of deciding the criteria and sub-criteria, in addition to their preference of the suppliers’ performance with respect to sub-criteria are considered in linguistic terms. To handle the subjectivity of decision makers’ assessments, fuzzy logic has been applied and a new ranking method on the basis of fuzzy inference system (FIS) is proposed for supplier selection problem. Finally, an illustrative example is utilized to show the feasibility of the proposed method.     

基于Sugeno型模糊推理算法的模糊控制器及其应用

介绍了Sugeno型模糊推理算法的基本原理,给出了一种实现方法,并对其控制性能进行了仿真.     

基于模糊知识的混合推理技术研究与应用

针对模糊知识的内在联系,提出了一种模糊推理与逆向推理相结合的混合推理技术,介绍了该技术的设计思想,结合模糊知识实现了算法,重点论述了模糊推理与逆向推理相结合的推理过程,实现了一种较为理想的不确定性推理方法,有效地提高了推理机的执行效率。     

A fuzzy MCDM method and an application to solid transportation problem with mode preference

In this paper we propose a computationally efficient fuzzy multi-criteria decision making (FMCDM) method. For this purpose we define a ranking function based on credibility measure to rank a fuzzy number over another fuzzy number. A comparative result of our proposed ranking method with the other well known methods is provided. The proposed FMCDM method is successfully applied to find most preferred transportation mode among available modes with respect to some evaluation criteria for a solid transportation problem (STP). Here the evaluation ratings of the alternatives and criteria weights are presented in terms of linguistic variables. The importance weights of the available transportation modes as obtained by this method are then assigned to the STP. Numerical example is provided to illustrate the proposed method and problem.     

A characteristic-point-based fuzzy inference system aimed to minimize the number of fuzzy rules

This paper presents a characteristic-point-based fuzzy inference system (CPFIS) for fuzzy modeling from training data. The aim of the CPFIS is not only satisfactory precision performance, but also to employ as few purely linguistic fuzzy rules as possible by using a minimization-based systematic training method. Characteristic points (CPs) are defined as the few data points among the original training data which, when they are directly mapped to fuzzy rules and thus form the entire rule base, allow the underlying system to be effectively modeled. Three minimization-based algorithms in a sequence are proposed to train the CPFIS: a gradient-projection method, a Gauss-Jordan-elimination-based column elimination, and back-propagation. The CPs are determined by iterative computations of the first two minimization algorithms, after which the resulting fuzzy sets are further fine-tuned by the third algorithm. Experiments conducted on three benchmark problems showed that the CPFIS used one of the smallest number of fuzzy rules among the reported results for other methods. The Gaussian membership functions in both the input and output fuzzy sets and the small number of fuzzy rules make the rule interpretation of the CPFIS much easier than that of other methods, thus enhancing human-computer cooperation in knowledge discovery.     

Solution of fuzzy multi-objective project crashing problem

Project management is a very important field employed for scheduling activities and monitoring the progress, in competitive and fluctuating environments. The feasible duration time required to perform a specific project is determined using critical path method. However, because of competitive priorities, time is important and the completion time of a project determined using critical path method should be reduced to meet a deadline requested. In this situation, project crashing problem arises. Project crashing analysis is concerned with shortening the project duration time by accelerating some of its activities at an additional cost. In general, the parameters of the problem are accepted as certain and the project crashing problems are solved using deterministic solution techniques. In reality, because of uncertain environment conditions, incomplete or unobtainable information, there can be ambiguity in the parameters of the problem. The uncertainty in the parameters can be modeled via fuzzy set theory. Using fuzzy models gives the chance of better project management decisions with more stability under uncertain environmental factors. In the literature, various authors solved different fuzzy versions of project management problems via transforming them into their crisp equivalents. In this study, a fuzzy multi-objective project crashing problem with fuzzy parameters is handled. The fuzzy project crashing problem is solved with a direct solution approach based on fuzzy ranking methods and the tabu search algorithm.     

A hybrid multi-objective approach based on the genetic algorithm and neural network to design an incremental cellular manufacturing system

One important issue related to the implementation of cellular manufacturing systems (CMSs) is to decide whether to convert an existing job shop into a CMS comprehensively in a single run, or in stages incrementally by forming cells one after the other, taking the advantage of the experiences of implementation. This paper presents a new multi-objective nonlinear programming model in a dynamic environment. Furthermore, a novel hybrid multi-objective approach based on the genetic algorithm and artificial neural network is proposed to solve the presented model. From the computational analyses, the proposed algorithm is found much more efficient than the fast non-dominated sorting genetic algorithm (NSGA-II) in generating Pareto optimal fronts.     

Normal-boundary intersection based parametric multi-objective optimization of green sand mould system

In manufacturing engineering optimization, it is often that one encounters scenarios that are multi-objective (where each of the objectives portray different aspects of the problem). Thus, it is crucial for the engineer to have access to multiple solution choices before selecting of the best solution. In this work, a novel approach that merges meta-heuristic algorithms with the Normal Boundary Intersection (NBI) method is introduced. This method then is used generate optimal solution options to the green sand mould system problem. This NBI based method provides a near-uniform spread of the Pareto frontier in which multiple solutions with gradual trade-offs in the objectives are obtained. Some comparative studies were then carried out with the algorithms developed and used in this work and that from some previous work. Analysis on the performance as well as the quality of the solutions produced by the algorithms is presented here.     

基于改进模糊神经推理的武器装备系统组合决策

针对武器装备系统组合决策问题,提出了一种新的基于自适应模糊神经推理的组合决策模型。首先用由高斯函数表示的模糊集定量描述武器系统的作战效能和敏捷性;接着基于波士顿投资组合矩阵进行武器系统模糊分类,建立自适应神经网络;最后利用鸟群算法优化模型相关参数。在样本数据库上的仿真结果表明,该方法可以反映武器系统组合状态,使决策者可以根据需求对组合策略进行调整更新。此外鸟群算法优化后的模型能够在一定程度上提高分类精度,与传统模型相比,具有更低的均方误差和更高的误差容忍率。     

A decision support system for engineering design based on an enhanced fuzzy MCDM approach

Design concept is an important wealth-creating activity in companies and infrastructure. However, the process of designing is very complex. Besides, the information required during the conceptual stage is incomplete, imprecise, and fuzzy. Hence, fuzzy set theory should be used to handle linguistic problem at this stage. This paper presents a fuzzy integrated approach to assess the performance of design concepts. And those criteria rating, relative weights and performance levels are captured by fuzzy numbers, and the overall performance of each alternative is calculated through an enhanced fuzzy weighted average (FWA) approach. A practical numerical example is provided to demonstrate the usefulness of this study. In addition, this paper, in order to make computing and ranking results easier to increase the recruiting productivity, develops a computer-based decision support system to help make decisions more efficiently.     

基于自适应神经网络模糊推理系统的蓄电池SOH预测

针对装甲车辆铅酸蓄电池健康状况影响因素复杂、难以准确预测的特点,提出了基于自适应神经网络模糊推理系统的蓄电池SOH预测模型。在确定模型的输入变量后,对其进行了MATLAB仿真和实测数据验证分析。结果表明,该模型具有很高的预测精度,在装甲车辆铅酸蓄电池SOH预测上具有很高的实用价值。