机床设备选择模型建立及综合评价

应用模糊综合评价理论建立数学模型来评价数控机床,使这种评价科学,实用。     

一种基于模糊逻辑的网络信任模型

在传感器网络中,为了便于各种传感器设备进行通信,研究并提出了一种基于模糊逻辑的信任模型。在复杂的传感器网络中,传感器必须知道他们自身高效、安全、可衡量的信任通信,实现了信任的定性与定量的转换。在传感器中,信任是网络通信能够快速、顺利进行的重中之重。将提出的模型应该在传感器网络中,旨在说明在沟通算法中,如何使用信任机制来选择从源到目的地最优路径。     

切削用量模糊优化选择的新方法

给出了新的更为合理而简捷的切削用量优化选择模糊数学模型及其求解方法。     

A fuzzy based decision model for nontraditional machining process selection

Manufacturing systems are processes in which inputs obtained from interior and exterior sources are transformed into an output by gathering inputs in an optimal way to guide the enterprises. Machining process plays a critical role in industry, and thus, directly affects the efficiency of the manufacturing systems. Due to different importance of the conflicting criterions, the multi-criteria decision-making methods are extremely useful in the selection process of the proper machining type. This study provides distinct systematic approaches in fuzzy and crisp environments to deal with the selection problem of proper machining process and proposes a decision support model for the guidance of decision makers to assess potentials of seven distinct nontraditional machining processes, namely laser beam machining, plasma arc machining, water jet machining, abrasive water jet machining, electrochemical machining, electrical discharge machining (EDM), and wire–EDM in the cutting process of carbon structural steel with the width of plate of 10 mm. The required data for decision and weight matrices are obtained via a questionnaire to specialists, as well as by deep discussions with experts and making use of past studies. Finally, an application of the proposed model is also performed via the SETED 1.0 software to show the applicability of the model.     

A decision-making framework model for material selection using a combined multiple attribute decision-making method

Material selection is a difficult and subtle task due to the immense number of different available materials. In choosing the right material, there is not always a single definite criterion of selection and the designers and engineers have to take into account a large number of material selection criteria. This paper presents a logical procedure for material selection for a given engineering design. The procedure is based on a combined TOPSIS and AHP method. The proposed material selection index helps to evaluate and rank the materials for a given engineering design. Two examples are included to illustrate the approach.     

依据模糊综合评判的减速器选型方法研究

依据模糊综合评判原理,对减速器选型的主要因素进行定量化处理,建立了减速器选型模糊综合评判模型,讨论了隶属度函数的确定方法,并进一步结合实例对减速器选型进行了叙述.     

A fuzzy multi-objective programming model for supplier selection with volume discount and risk criteria

In contemporary supply chain management, the performance of potential suppliers is evaluated against multiple criteria. In this paper, a fuzzy multi-objective programming model is outlined to propose supplier selection taking quantitative, qualitative, and risk factors into consideration. Also quantity discount has been considered to determine the best suppliers and to place the optimal order quantities among them. The mixed integer derivative nonlinear programming is obtained from fuzzy multi-objective programming model by chance-constrained method. To solve this problem, an innovative method is proposed. In addition, several “what if” scenarios are facilitated. Finally, a real-life sample is used to validate the proposed model.     

A multicriteria intuitionistic fuzzy group decision making for plant location selection with ELECTRE method

Plant location selection, the process of finding a suitable location for plant of a project has a strong influence on the success of industrial venture with the goal to minimize cost and maximize the use of resources. Thus, plant location selection problem is a multicriteria decision-making problem involving several conflicting criteria on which decision makers' knowledge is vague and imprecise. Therefore, in this study, the elimination and choice translating reality (ELECTRE) method is proposed with intuitionistic fuzzy sets for selection of appropriate plant location in group decision-making environment to tackle uncertainty of the information provided by decision makers and a plant location selection problem is considered to illustrate the proposed intuitionistic fuzzy-ELECTRE method. The ratings of alternatives with respect to each criterion and the weights of each criterion are taken as linguistic terms further characterized by triangular intuitionistic fuzzy sets.     

A fuzzy bi-objective mathematical model for optimum portfolio selection by considering inflation rate effects

Selecting and scheduling of project portfolios from a given set of investment proposals is one of the most important problems for which managers take several aspects into consideration. Inflation rate as one of these aspects is inherently uncertain, and because of this, various inflation rates can cause risky environments. Since risk can be decision driver for a proper selection, the purpose of this paper is fixed to minimize the risk and maximize the projects rate of return as two conflict objectives by considering inflation rate effects. A bi-objective mathematical programming model with fuzzy parameters is developed and well-known NSGA-II is applied to solve the developed model. Pareto plot of two conflict objectives helps decision maker (DM) to choose the best solution based on DM’s acceptable risk level. Moreover, the proposed model makes the project portfolio selection process more effective with developing a novel mathematical programming by sharing limited available budgets and resources. Finally, numerical results indicate the effectiveness of the proposed model with consideration the inflation rate effects on selecting project portfolios.     

基于事例的供应商选择模型与方法研究

供应商选择是供应链管理的重要内容。本文根据供应商选择的特点,采用基于事例推理的技术研究供应商选择的决策方法,建立了基于事例推理的供应商选择过程模型。进一步,应用模糊集理论,研究了供应商选择事例的表示与检索,提出了一种考虑模糊特征隶属度函数值的相似度检索方法。最后,给出了基于事例的供应商选择系统的应用实例。     

工艺规划为核心的产品协同研发生产平台

为实现具有市场竞争力产品的高端研发,并具备较高的质量及成本控制能力,文中提出构建以工艺规划为核心的产品数字化研发生产平台的解决思路.平台框架包含计算机辅助设计、产品数据管理、计算机辅助工艺规划和协同制造模块;通过工艺与设计、生产两端的数据共享,实现设计、工艺数据和生产的高效协同;通过工艺规划方案的功能描述,展现了一个为...     

A design model for circular porous air bearings using the 1D generalized flow method

Although the working principles of porous air bearings have been known for many years, most calculation procedures still involve specialized 3D CFD techniques which are not very useful to design engineers who initially require first-order engineering models for feasibility studies. This paper presents a simple design model for a circular porous air bearing based on well-established 1D generalized flow theory. Understanding porous air bearing mechanics is relatively easy with the proposed design model because it captures the essential physical phenomena governing the airflow. Moreover, the 1D model has a very simple architecture that allows easy design synthesis and requires minimal computational requirements. Comparison with experimental data shows accuracy comparable to specialized 3D techniques.     

模糊多属性决策方法在绿色材料选择中的应用

为解决绿色设计中材料选择的多目标优化问题,提出一种由改进相似性灰色关联度和理想解法相结合的模糊多属性决策方法.该方法将材料的选择和回收处理的方法结合起来组成组合系列,采用生态指数定量分析评估材料及其过程的全生命周期环境影响,基于改进的灰色相似性关联度计算相似贴近度(SCD),基于理想点法(TOPSIS)计算距离贴近度(DCD),基于与相似贴近度的偏差和与距离贴近度的偏差和最小的原则建立非线性规划模型,求出集成贴近度(ICD),进而确定按集成贴近度排序的最优组合序列.最后通过一个实例详细说明了决策的过程,比较结果表明该方法相对于其他决策方法具有一定的优越性.     

A new fuzzy group multi-criteria decision making method with an application to the critical path selection

In this paper, we propose a new fuzzy group multi-criteria decision making method and apply it to determine the critical path in a project network. The criteria used here are time (expected duration), cost, risk, and quality of the project activities that are considered critical in project management. As each criterion has its independent level of importance in the critical path selection, the weights of the project criteria are also considered in the analysis. Considering that the information in terms of various project activities and criteria weights are often incomplete and/or uncertain in real-world situations, the essential information in terms of the criteria and project activities are obtained using triangular fuzzy numbers and/or linguistic variables that are mapped to triangular fuzzy numbers, wherever appropriate. The proposed method involves fuzzy evaluation based on the fuzzy information of the possible project paths on each criterion leading to the strength and weakness index scores of the project paths. We define a measure of criticality termed as the total performance score of each project path obtained using its strength and weakness index scores. The path that has the highest measure of criticality is selected as the critical path. A numerical illustration is provided to demonstrate working of the proposed methodology. Further, a case study from manufacturing engineering industry is also presented to better justify the applicability and potentials of the proposed methodology. A comparison with closely related fuzzy multi-criteria decision methods for the critical path selection is done to analyze the performance of the proposed methodology.     

一种基于逆模糊模型的自适应逆控制方法

利用模糊逆建模方法,结合自适应逆控制思想,提出了一种基于模糊逆模型的自适应逆控制方法。首先利用模糊系统理论对未知非线性对象进行离线逆建模,得到模糊逆模型;然后将对象与初始逆模型进行串联,利用LMS算法在线调节逆模型,同时将其进行数字复制作为系统控制器,与对象进行串联。该方法可用较少的模糊规则数达到很好的跟踪控制效果,将该方法用于一混合非线性系统及球形液位控制中,仿真结果验证了该方法的有效性与实用性。     

Cost prediction method based on an improved fuzzy model

Scientific cost prediction is the foundation for formulating a business plan, which helps enterprises to determine the target costs and to control the operating costs. In today’s world, quantitative methods are crucial for prediction purposes in cost management. On the basis of studying some typical methods of cost prediction, we propose a cost prediction method based on an improved fuzzy model. Firstly, owning to the inefficiency of existing fuzzifier, such that it is difficult to determine the number of fuzzy rules, we present an improved fuzzy c-means (FCM) fuzzifier to solve this problem referring to “granulation–degranulation” strategy and sample error function. Secondly, a fuzzy model based on the improved FCM fuzzifier is constructed through combining Takagi–Sugen–Kang fuzzy inference system. The algorithm of the improved fuzzy model is also realized by this study. Finally, through a series of experimental analyses for steel number product and steel class product of certain machinery enterprise, the results have demonstrated that the proposed method has the better prediction accuracy, which can be used effectively and practically in real-world cost prediction.     

An improved updating parameter selection method and finite element model update using multiobjective optimisation technique

Finite element model updating is a procedure to minimise the differences between analytical and experimental results and is usually posed as an optimisation problem. In model updating process, one requires not only satisfactory correlations between analytical and experimental results, but also maintaining physical significance of updated parameters. For this purpose, setting up of an objective function and selecting updating parameters are crucial steps in model updating. These require considerable physical insight and usually trial-and-error approaches are common to use. In conventional model updating procedures, an objective function is set as the weighted sum of the differences between analytical and experimental results. But the selection of the weighting factors is not clear since the relative importance among them is not obvious but specific for each problem. In this work, multiobjective optimisation technique is introduced to extremise several objective terms simultaneously. Also the success of finite element model updating depends heavily on the selection of updating parameters. In order to avoid an ill-conditioned numerical problem, the number of updating parameters should be kept as small as possible. Such parameters should be selected with the aim of correcting modelling errors and modal properties of interest should be sensitive to them. When the selected parameters are inadequate, then the updated model becomes unsatisfactory or unrealistic. An improved method to guide the parameter selection is suggested.