Neural Network Based Multi-level Fuzzy Evaluation Model for Mechanical Kinematic Scheme

To implement a quantificational evaluation for mechanical kinematic scheme more effectively,a multi-level and multi-objective evaluation model is presented using neural network and fuzzy theory. Firstly,the structure of evaluation model is constructed according to evaluation indicator system. Then evaluation samples are generated and provided to train this model. Thus it can reflect the relation between attributive value and evaluation result,as well as the weight of evaluation indicator. Once evaluation indicators of each candidate are fuzzily quantified and fed into the trained network model,the corresponding evaluation result is outputted and the best alternative can be selected. Under this model,expert knowledge can be effectively acquired and expressed,and the quantificational evaluation can be implemented for kinematic scheme with multi-level evaluation indicator system. Several key problems on this model are discussed and an illustration has demonstrated that this model is feasible and can be regarded as a new idea for solving kinematic scheme evaluation.

FUZZY COMPREHENSIVE EVALUATION MODEL OF ECOLOGICAL DEMONSTRATION AREA

Ecological demonstration area (EDA) is an authorized nomination, which should be assessed from several aspects, including ecological, social, environmental, economic ones and so on. It is difficult to advance an exact developing level index of EDA due to its indicator system’s complexity and disequilibrium. In this paper, a framework of indicators was set to evaluate, monitor and examine the comprehensive level of ecological demonstration area (EDA). Fuzzy logic method was used to develop the fuzzy comprehensive evaluation model (FCEM), which could quantitatively reveal the developing degree of EDA. Huiji District of Zhengzhou, Henan Province, one of the 9th group of national EDAs, was taken as a study case. The framework of FCEM for the integrated system included six subsystems, which were social, economic, ecological, rural, urban and accessorial description ones. The research would be valuable in the comprehensive quantitative evaluation of EDA and would work as a guide in the construction practices of Huiji ecological demonstration area.

Comprehensive Evaluation Model of Livable City Based on Fuzzy Comprehensive Evaluation Method

This paper firstly introduced the degree of livability of a city from the social civilization,economic affluence,environmental beauty,resource carrying capacity,and life convenience. Based on the principle of the fuzzy comprehensive evaluation,it analyzed the connection between influencing factors,and established a comprehensive evaluation model for calculation of the livability index of a city. Finally,it obtained the relative livability of each city and the ranking of livability of each city.

Risk Evaluation Based on Variable Fuzzy Sets and Information Diffusion Method

Risk evaluation is an effective way to reduce the impacts of natural hazards and it plays an increasingly important role in emergency management. Traditional methods of assessing risks mainly utilize Geographic Information System (GIS) to get risk map, and information diffusion method (IDM) to deal with incomplete data sets. However, there are few papers discuss the uncertainty of integrated hazards and consider dynamic risk under time dimension. The model proposed in this study combines the variable fuzzy set theory with information diffusion method (VFS-IDM) to solve the uncertainness of multiple hazards dynamic risk assessment when data sets are incomplete. This study employs fuzzy set theory (VFS) to calculate the relative membership degree and applies information entropy method (IEM) to obtain the weights of criteria indicators for multiple hazards evaluation. Then applies information diffusion method (IDM) to estimate condition probability distribution and vulnerability curve with the VFS-IEM model results, time data and multiple hazards losses. Then the expected value of multiple hazards dynamic risk can be calculated by using the normal information diffusion estimator so as to improve the accuracy of risk evaluation results.

Comprehensive benefit of flood resources utilization through dynamic successive fuzzy evaluation model: A case study

Taking the flood resources utilization in Baicheng, Jilin during 2002–2007 as the research background, and based on the entropy weight and multi-level & multi-objective fuzzy optimization theory, this research established a multi-level & semi-constructive index system and dynamic successive evaluation model for comprehensive benefit evaluation of regional flood resources utilization. With the year 2002 as the base year, the analyzing results showed that there existed a close positive correlation between flood utilization volume and its benefits, comprehensive evaluation value and its comparison increment. Within the six successive evaluation years, the comprehensive benefit of 2003 was the best, in which the benefit evaluation increment reached 82.8% whereas the year of 2004 was the worst, in which the increment was only 18.2%. Thus the sustainability and correctness of the evaluation were verified by six years successive evaluation and increment comparison. The analyzing results showed that the economic benefits, ecological benefits and social benefits of flood utilization were remarkable, and that the comprehensive benefit could be improved by increasing flood utilization capacity, which would promote the regional sustainable development as well. The established dynamic successive evaluation provides a stable theoretical basis and technical support for further flood utilization.

Determination of amount of irrigation and nitrogen for comprehensive growth of greenhouse cucumber based on multi-level fuzzy evaluation

In the northwestern part of China,rational and efficient management of irrigation and nitrogen significantly affects the intensive production of greenhouse cucumbers(Cucumis sativus L).To evaluate the effects of different combinations of water use and nitrogen(N)on yield,quality,and profitability of the greenhouse cucumbers that planted in 2018 Spring,nine combined treatments were applied.Results indicated the optimal irrigation and nitrogen demands for yield,quality and other indicators were different.The irrigation amount significantly affected the yield,and the yield gradually increased with increasing in irrigation.Single fruit weight(SFW)was significantly affected by the amount of irrigation,nitrogen and their interactions,and the higher amounts of N and irrigation were beneficial to the increase of SFW.The partial factor productivity of the applied N(PFPN)gradually increased with the nitrogen amount decline.Irrigation water use efficiency(IWUE)was closely related to the amount of irrigation.The higher irrigation amount would lead to the lower IWUE.When the amounts of irrigation and nitrogen were at an intermediate level,the content of vitamin C(VC)reached the maximum.As the amount of nitrogen was increased or irrigation was decreased,the Nitrate content(NC)would increase.Free amino acid(FAA)and NC followed a similar variation.When the amounts of irrigation and nitrogen both were at medium levels,the total soluble sugar concentration(TSSC)reached the highest.The multi-level fuzzy evaluation method was used to evaluate different indicators of cucumber.The weights of indicators in the first and second layer were determined by analytic hierarchy process(AHP)and entropy weight method,respectively.Then the fuzzy algorithm was used to comprehensively evaluate all the treatments.The evaluation results show that T4(irrigation,1957.6 m3/hm2;N,210 kg/hm2)is the best strategy for greenhouse cucumber irrigation and nitrogen management in the northwestern part of China.

Fuzzy pattern recognition model of geological sweetspot for coalbed methane development

From the perspective of geological zone selection for coalbed methane(CBM) development, the evaluation parameters(covering geological conditions and production conditions) of geological sweetspot for CBM development are determined, and the evaluation index system of geological sweetspot for CBM development is established. On this basis, the fuzzy pattern recognition(FPR) model of geological sweetspot for CBM development is built. The model is applied to evaluate four units of No.3 Coal Seam in the Fanzhuang Block, southern Qinshui Basin, China. The evaluation results are consistent with the actual development effect and the existing research results, which verifies the rationality and reliability of the FPR model. The research shows that the proposed FPR model of geological sweetspot for CBM development does not involve parameter weighting which leads to uncertainties in the results of the conventional models such as analytic hierarchy process and multi-level fuzzy synthesis judgment, and features a simple computation without the construction of multi-level judgment matrix. The FPR model provides reliable results to support the efficient development of CBM.

To Evaluate of the Self-dependent Innovation Ability of Equipment Manufacturing Enterprises in Shaanxi Province

For an enterprise, what is important is to have the self-dependent innovation ability so that it can en- hance the core competence unceasingly and acquire sustainable competitive advantages. In this paper, the indi- cator system of the self-dependent innovation ability of equipment manufacturing enterprises in Shaanxi province is constructed, in which includes 4 one-level indicators and 13 two-level indicators; and conducts empirical re- search by applying the multi-level fuzzy comprehensive evaluation method.

铰接式基础风力机多目标优化及动力响应研究

针对一种新型铰接式基础风力机的基础结构设计与优化问题,综合考虑风力机运行安全稳性、经济成本及运动性能等多方面因素,本文建立了高维三目标优化数学模型,采用一种基于参考点的非支配排序多目标遗传算法(NSGA-Ⅲ)对风力机基础结构尺寸进行优化设计研究,利用模糊优选方法,对所得到的帕累托解进行模糊评价,得到满足不同评价指标下的最优方案;并在此基础上,采用空气动力-水动力-结构耦合分析方法,利用Matlab在时域内编写运动控制方程进行动力响应分析。计算结果表明:额定风速海况下,所设计的铰接式基础风力机满足安全发电作业要求,同时相比于初始设计方案,基于多目标优化算法及模糊评价所设计的基础结构无论是运动及载荷性能都更加优越,经济成本更低;相关算法及优化流程也为后续不同基础形式的优化设计工作提供了新思路和参考。

基于模糊理论的立式磁轴承系统保护轴承抗冲击影响因素分析

为分析立式磁轴承失效后保护轴承受转子冲击的影响因素及其影响程度,仿真立式磁轴承系统中转子跌落至保护轴承的动力学过程,建立Ⅰ-Ⅱ级模糊综合评价模型对保护轴承所受轴向碰撞力各影响参数的影响程度进行评判,并利用熵权法、灰色关联度法对模型进行验证,结果表明:随着转子质量、轴向保护间隙、转子偏心角度增大以及有保持架更换为无保持架,保护轴承内圈所受最大轴向碰撞力增大,随着填球数增大,最大轴向碰撞力先减小后增大,而转子转速、滚动体材料、径向保护间隙的变化对轴向碰撞力的影响不大;各参数的影响程度从大到小为转子质量、保护轴承填球数、轴向保护间隙、转子偏心角度、保护轴承有无保持架、滚动体材料、转子转速、径向保护间隙;模糊综合评价模型与熵权法、灰色关联度法的评价结果基本一致,验证了在乏信息条件下利用模糊综合评价模型评价各参数对保护轴承所受轴向碰撞力的影响程度的有效性。

基于动态三角模糊数与改进TOPSIS法的居住建筑设计方案评价决策

针对居住建筑设计方案的多属性决策问题,本文建立了包括建筑性能、适用因素、场地条件、环境协调和经济合理等5方面因素的居住建筑设计方案综合评价决策指标体系。为便于专家对评价指标属性进行评价和真实地表达专家评价信息,采用动态三角模糊数对指标属性等级进行赋值与量化。其次,考虑专家知识经验主观和熵值法客观的指标赋权不同影响,采用组合权重使指标赋权更加科学,构建区间值欧氏距离和区间值灰色关联度的改进TOPSIS(technique for order preference by similarity to an ideal solution)法的居住建筑设计方案综合评价决策模型,解决了指标间重要性差异与指标间相关性的问题。最后,将综合评价决策模型对4个居住建筑设计方案的优劣进行排序,与基于满意度的建筑方案实证评价结果一致。研究结果表明:该综合评价决策模型能够合理选择最优方案,为定量研究居住建筑设计方案综合评价决策提供了新的思路。

A new approach to fuzzy dynamic fault tree analysis using the weakest n-dimensional t-norm arithmetic

Dynamic fault tree analysis is widely used for the reliability analysis of the complex system with dynamic failure characteristics. In many circumstances, the exact value of system reliability is difficult to obtain due to absent or insufficient data for failure probabilities or failure rates of components. The traditional fuzzy operation arithmetic based on extension principle or interval theory may lead to fuzzy accumulations. Moreover, the existing fuzzy dynamic fault tree analysis methods are restricted to the case that all system components follow exponential time-to-failure distributions. To overcome these problems, a new fuzzy dynamic fault tree analysis approach based on the weakest n-dimensional t-norm arithmetic and developed sequential binary decision diagrams method is proposed to evaluate system fuzzy reliability. Compared with the existing approach,the proposed method can effectively reduce fuzzy cumulative and be applicable to any time-tofailure distribution type for system components. Finally, a case study is presented to illustrate the application and advantages of the proposed approach.

医疗设备使用评价指标体系的研究与实践

目的构建一套完整的医疗设备使用评价指标体系,提升医院设备管理精细化水平。方法采用文献分析法、专家咨询法和模糊层次分析法构建了医疗设备评价指标体系指标库。以医院9条内镜为例,通过对2023全年指标数据的获取、计算、赋分等步骤,开展实证分析。结果构建了一套完整的医疗设备使用评价指标体系,包含4项一级指标和18项二级指标。运用功效系数法,对九条内镜的使用管理及综合能力进行评分和排名,并针对不足提出改进建议。结论设备使用评价指标体系的运用,可以实现更加高效的设备动态管理机制,促进设备使用管理工作不断完善。

基于联盟博弈的多虚拟电厂参与日前电力市场竞标模型

当前多虚拟电厂联盟面临售电垄断防范机制匮乏、个体主观性偏好难以多维评估刻画等问题。提出基于联盟博弈的多虚拟电厂参与日前电力市场竞标模型。引入联盟内部动态过网费机制,量化内部功率交互产生的增量运行成本,以防售电垄断;计及虚拟电厂个体在联盟选择问题上的多指标偏好性,建立基于模糊层次分析法-决策试行与评价实验室法的联盟选择结果评估框架,以充分刻画多指标关联性;采用合并-分裂规则构建分布式联盟方案,通过求解配电网-多虚拟电厂联盟双层博弈模型获取多指标评分,基于综合评估结果进行迭代,获得最优联盟方案。算例结果验证了所提模型的有效性及经济性。

基于模糊Borda法的电动汽车负荷对配电网影响综合评估研究

电动汽车行业的高速发展必将对电网运行带来巨大压力,因此需要通过电动汽车对配电网影响的精准研究得到应对之法。本文构建了电动汽车充电负荷时空分布预测模型以及电动汽车接入配电网综合评估体系。首先,运用多源数据、多因素能耗模型、动态路网模型以及路-电耦合理论预测电动汽车充电负荷时空分布结果;其次,从合理性、安全性、经济性、可靠性以及环保性5项准则出发构建相应的量化指标,建立综合评估体系;最后,运用综合赋权法得到指标权重集,并运用模糊Borda法集合多种综合评估方法,协调各评价方法对评价对象的主客观性影响从而得到综合评估结果。最后,以上海某地区为例进行算例仿真,验证了本文方法的可行性。

基于模糊Borda序值的装备体系构建方案动态论证方法

针对采用不同方法对装备体系构建方案作战效能论证评估结论不一致性问题,提出了基于模糊Borda序值的动态论证方法。立了不同论证方法及其事前检验、综合不同论证结论的模糊Borda数、综合论证结论与不同论证结论的事后检验等关键模型和算法;给出了某型通信对抗装备体系构建方案的动态论证算例。实例分析结果表明了该方法的有效性和合理性,为合理解决多种装备体系构建方案论证评估结论非一致性问题提供了思路。

基于水土资源承载评价的灌区水土资源时空优化配置研究

以贵州省某典型灌区为例,利用系统动力学、压力-状态-响应模型等,建立水土资源承载能力的评价方法。验证分析显示,灌区1996、2004、2012和2020年的水土资源承载状态分别为轻度、逼近、逼近和平稳。结果表明,研究提出的评价体系对灌区水土资源承载能力分析具有合理性和可行性,灌区的水土资源承载状态在空间中为积极性变化,但变化速度减缓,严峻以及轻度承载面积在空间分布中逐渐向盐碱化等趋势过渡。

基于省级数据的电力发展水平动态综合评价方法

电力发展水平的量化综合评价对准确认识地区电力发展的特点和趋势具有重要意义。对电力发展水平的评价指标体系、动态综合评价方法和评价结果分析进行研究。建立电力发展水平评价的三级指标体系,从经济能源协调度、发电水平、用电水平、供电水平和电力发展潜力5个方面刻画地区电力发展水平。提出考虑主观权重约束的改进投影寻踪方法建立静态评价模型,将模糊专家评价和权数非独裁条件以约束形式嵌入投影寻踪模型,实现主观专家意见和客观数据信息的结合;利用时序信息熵确定时序加权向量,将各时间断面的静态评价模型集结,建立电力发展水平动态综合评价模型。以1994至2013年全国30个省、市、自治区的数据为样本,通过横向、纵向对比二级指标评价值和电力发展水平综合评价值,分析中国电力工业发展的地区差异、特点及潜力。

故障模糊预测系统建模方法研究

以模糊综合评判理论为基础 ,提出了一种动态的故障预测模型 ,并探讨了动态模糊关系矩阵的确定方法 。

动态联盟合作伙伴选择的多层次模糊综合评判方法

合作伙伴选择问题是动态联盟组建过程中的重要决策问题之一。这类问题涉及的因素较多,本质上是多目标决策问题。论文运用模糊理论和模糊思维,将定性分析和定量分析相结合,提出了合作伙伴的多层次模糊综合评判方法,为合作伙伴选择提供了一种更能符合客观实际,且简便可行的方法。最后,用实例说明了该方法在选择合作伙伴的有效性。