基于熵值和TOPSIS 法的装备体系方案优选方法

针对传统的方案筛选方法会产生海量数据且评估不客观的问题,提出一种基于熵值和 TOPSIS 法的装备体系方案优选方法。在确定装备体系方案优选指标的基础上,构建了基于熵值赋权的 TOPSIS 法装备体系方案价值评估与优选模型,并通过实例验证了该模型的有效性。结果表明：该方法能有效提高装备体系方案优选的科学性、客观性和有效性,从而为装备论证人员开展装备体系方案优选工作提供参考。     

基于改进FMEA法的装配式混凝土建筑建造质量风险评价

为了有效分析装配式混凝土建筑关键建造质量风险因素，提高相关方质量管理水平，对建造质量风险因素进行收 集归纳，建立装配式混凝土建筑建造质量风险评价指标体系，提出基于模糊 TOPSIS 和变权法改进的 FMEA 风险评价模型。 考虑装配式混凝建筑风险指标评价要素状态值的多变性，将惩罚型变权法引入评价要素客观权重确定中，建立各风险指标 评价要素的加权规范化矩阵，再利用 TOPSIS 逼近理想解的原理进行风险排序，得到风险优先等级，并结合实例验证该方 法的可行性和可操作性，从而为装配式混凝土建造质量风险管理提供一种新思路。     

金属矿床评价计算模型的综合比较与选优

评估体系是实现企业开发决策及其科学生产的主要手段。本文通过对综合评价法、TOPSIS法和ELECTRE法的分析与比较,将三种算法相济运用;在三种算法所得结果不一致时,得出用社会选择方法来判定那个方法的评价结果可信度更高的结论。     

Assembly line balancing by a new multi-objective differential evolution algorithm based on TOPSIS

In this paper, we propose a multi-objective differential evolution algorithm (MODEA) to solve the multi-objective simple assembly line balancing problem type-2 (SALBP-2). This problem arises when in an existing assembly line, changes in the production process or demand structure take place and the organisation wants to produce the optimum number of items using a fixed number of workstations, which is associated with optimally assigning the tasks to an ordered sequence of stations such that the precedence relations are not violated and some measures of performance are optimised. The two considered objectives are: minimising the cycle time and the smoothness index of the assembly line. To that purpose, we develop a MODEA which unlike the existing algorithms deals with the considered objectives separately in selecting the next population members by proposing a new acceptance scheme based on the Pareto dominance concept and a new evaluation scheme based on TOPSIS. Also, by using the Taguchi method, we tune the effective factors of the developed algorithm. Then its efficiency is tested over available assembly line balancing benchmarks and compared to a new algorithm provided recently in the bi-objective SALBP-2 literature. Computational experiments indicate that the developed algorithm outperforms the existing meta-heuristic over a large group of benchmarks.     

基于TOPSIS的印刷设备选购方法

随着印刷科技的迅速发展和人们对印刷品质要求的逐步提高,印刷设备正日益呈现系统化、复杂化、数字化的发展态势.对于印刷企业来说,如何综合考量设备的功能、质量、价格以及自身实际需求等因素,以选择合适的印刷设备成为当务之急,因此,建立一套系统、科学、合理、有效的设备优选方案尤为重要.本文引入多属性模糊决策方法,提出一种基于TOPSIS法(双基准点法)的设备优选方法,为企业提供科学的决策依据.该方法首先确定设备采购的评价指标体系;其次,依据属性的不同权重,构造加权矩阵;最后利用备选设备与理想设备的距离和贴近度对备选设备进行排序,从而做出选择.本研究结合具体设备优选实例分析,通过与传统的加权求和方法的比较,验证了该方法的有效性和可行性.     

理想解法的改进及其在工程材料综合评价中的应用

用垂直距离代替欧氏距离,并对垂直距离加权,对传统理想解法进行了改进;并以航空航天用电绝缘材料的选择为例,从功能性角度出发,选择了8个评价指标,运用改进后的理想解法对5种经过初选的候选材料进行了综合评价。结果表明:石英玻璃的加权垂直距离最小,是最佳的候选材料,评价结果正确;改进后的理想解法不仅解决了传统方法的不足,而且更好地体现了不同候选材料的优劣差异,物理含义更加明确,分析问题更全面、客观,是工程选材的一种工具。     

Experimental investigation of dry,wet and cryogenic boring of AA 7075 alloy

In this research work, an attempt has been carried out to examine (investigate) and study the dry, wet and cryogenic boring of AA 7075 alloy, which is predominantly used in transport applications in defense (aeronautical parts), oceanic and automaker industries. To ensure direct supply of the coolant, and real-time measurement of cutting temperature a modified boring bar is used (modification is carried out using EDM to accommodate placement of a thermocouple to obtain real-time measurement of temperature readings during the boring cycle). It is observed that during cryogenic boring of AA 7075 alloy there is a considerable reduction in the cutting force (F_c), cutting temperature (T_c) and surface roughness (R_a) by 56.16%, 84.70%, 58.98% compared to dry boring and 48.43%, 80.70%, 34.70% compared to wet boring, respectively. Decrease in F_c and T_c leads to a reduction in high stresses at localized points during machining and in turn curtail wear in workpiece and tool. Lubrication provided by cryogenic fluids also plays a sizable role in reduction of F_c and T_c. Reduction in lower F_c and T_c has a glaring effect on the surface characteristics of the hole produced during the boring process. Tool wear is reduced in cryogenic boring by 36.96% and 17.57% compared to dry and wet boring, respectively. Taguchi and ANOVA was carried out which helped in determining feed as an important parameter with respect to F_c and R_a during boring of AA 7075 under dry, wet and cryogenic conditions whereas speed as an important parameter in determining T_c in dry and wet conditions and feed for T_c in cryogenic boring condition. TOPSIS analysis highlighted speed of 770 rpm and feed of 0.055 mm/min as the most closest to ideal solution for all three different cutting conditions. Surface morphology study after boring of AA 7075 highlighted better surface characteristics in cryogenic bored surface compared to dry and wet boring. Roughness measured in AFM for tool used in boring highlighted a decrease in 86.79% and 66.01% in cryogenic boring in juxtaposition with dry and wet boring, respectively. A surge in compressive residual stress is observed in cryogenic bored surface by 10.41% and 3.5% in juxtaposition with dry and wet boring, respectively, highlighting an abatement in tensile residual stress and better workpiece integrity as compared to dry and wet boring conditions.     

基于熵权TOPSIS模型的天津市海洋资源环境承载力评价

为评价和寻找影响天津市海洋资源环境承载力的关键因素,论文从海洋资源系统、海洋环境系统和社会经济系统中选取27项指标构建海洋资源环境承载力评价指标体系,运用熵权TOPSIS模型对天津市2007—2016年海洋资源环境承载力及3个子系统承载力进行评价,并采用灰色关联系数选择和识别影响承载力的关键因素。研究结果表明：2007—2016年天津市海洋资源环境承载力综合值处于0.341 2~0.566 4,为中等水平;2007—2016年天津市海洋资源环境承载力的发展态势呈“下降→平稳→上升→平稳”的趋势,其中2007—2010年呈不断下降趋势,2010—2012年呈较为平稳态势,2012—2014年明显上升,2014—2016年又逐步稳定;2007—2016年天津市海洋资源承载力变化幅度较低,海洋环境承载力呈先下降后上升趋势,社会经济承载力总体呈先下降后上升再下降趋势;采用灰色关联系数计算,发现SO2年度均值、环境污染治理投资占GDP比例等是影响天津市海洋资源环境承载力的关键因素。基于以上结论提出合理开发海洋资源、积极发展滨海旅游业等建议,以期提升天津市海洋资源环境承载力。     

电网节点电压暂降综合评估及其检验方法

准确评估电压暂降是改善和解决暂降问题的基础,而对评估方法的检验是评估质量的保障。针对现有暂降指标体系缺乏综合评估方法且评估结果无法定量检验的问题,文章基于IEEE Std 1564-2014指标体系标准,提出了一套电网节点电压暂降综合评估流程及其检验方法。针对目前暂降评估仅对暂降频次或幅值进行评估从而造成信息缺失的问题,文章从暂降频次、幅值、能量和严重程度等方面建立暂降综合评估数学模型;提出以指标预处理、指标赋权和评估结果检验为关键环节的电压暂降综合评估一般流程;文章提出了综合评估流程的检验方法,从辨识性、一致性、稳定性和有效性四个角度出发,对综合评估方法的各环节进行定量评价。综合评估结果能反映电网中暂降严重的节点或区域,检验方法能衡量不同评估方法的优劣,从而为暂降的分析与治理提供科学依据。基于蒙特卡洛方法,对IEEE 30节点系统进行仿真,验证了文章方法的合理性和准确性。