A quantitative analysis method for contact force of mechanism with a clearance joint based on entropy weight and its application in a six-bar mechanism

Contact force in a clearance joint affects the dynamic characteristics and leads to nonlinear response of the mechanism.It is necessary to assess the nonlinearity of contact force quantitatively.Therefore,a new method named contact-force entropy weight is proposed in this paper.This method presents a comprehensive description of the judgment matrix in the X,Y,and Z directions.To assess the influence degrees of different clearances and angular velocities on the contact force,the method is applied to numerical calculation and simulation of a six-bar mechanism with a clearance joint to illustrate its application and investigate the influence degree of angular velocity and clearance on the contact force.By combining the simulation results and theoretical calculations,the influence degrees of different clearances and angular velocities on the contact-force entropy weight of the six-bar mechanism with a clearance joint are revealed.It is found that the angular velocity has a significant influence on the contact force entropy weight of the clearance joint,showing that the contact-force entropy weight is a feasible new method of assessing non-linearity of contact force quantitatively.The method gives a theoretical reference for quantitatively analyzing the nonlinear dynamics.

An Availability Evaluation Method of Web Services Using Improved Grey Correlation Analysis with Entropy Difference and Weight

Web services is one of the basic network services, whose availability evaluation is of great significance to the promotion of users’ experience. This paper focuses on the problem of availability evaluation of Web services and proposes a method for availability evaluation of Web services using improved grey correlation analysis with entropy difference and weight (EWGCA).This method is based on grey correlation analysis, and use entropy difference to illustrate the changes of availability, set weight to quantize availability requirements of different operations or transactions in services. Through simulation experiment in high load scenarios for Web services, the experiment result shows that our method can realize hierarchical description and overall evaluation for availability of Web services accurately in the case of smaller test sample volumes or uncertain data even in the field of big data.

Cost-benefit Analysis of Scale Pig Breeding in Shandong Province Based on Modified Entropy Weight-TOPSIS Model

According to the relevant statistical data in National Agricultural cost-benefit Data Compilation(2001- 2013),we use the modified entropy weight- TOPSIS model to research the cost-benefit status of scale pig breeding in Shandong Province from the perspective of comparing it with that of the entire country and 9 other main pig producing areas. The results show that compared with the national average,the cost-benefit ratio of small scale pig breeding in Shandong Province is lower,while the cost-benefit ratio of medium scale and large scale pig breeding is significantly improved; the cost-benefit ratio of small scale pig breeding in Shandong Province is basically the same as that in 9 other main pig producing areas,while the cost-benefit ratio of medium scale and large scale pig breeding is higher; the output value of main products and the purchase price of piglet are two major bottlenecks restricting the cost-benefit improvement of scale pig breeding in Shandong Province.

Evaluation on Urban Land Ecological Security Based on the PSR Model and Matter-Element Analysis: A Case Study of Zhuhai, Guangdong, China

As one of the Special Economic Zones since the reform and opening up, Zhuhai has developed during the past 30 years. Its economic development, industrial structure and ecological environment have undergone great changes. Research on changes in Zhuhai’s land ecological security is of great significance. Using relevant data from 2007-2012, this study established a land ecological security assessment system based on the PSR conceptual framework model. The system contained 18 indicators from 3 aspects according to the concrete features of Zhuhai. Then we used the matterelement analysis and the improved entropy weight to analyze and evaluate the land ecological security of Zhuhai. The results showed that: from 2007 to 2012, the levels of the land ecological security of Zhuhai were “secure”, and the value increased year by year;as the land ecological security response value increased, Zhuhai was capable of solving land ecosystem problems. However, it should be noted that the structure of land ecosystem in Zhuhai has not formed and that rapid expansion of construction land has caused the shortage of cultivated land and other issues. Measures should be taken to control the construction area, improve land intensive utilization and improve the land ecological security.

Case Retrieval Strategy of Turning Process Based on Grey Relational Analysis

To solve the problem of long response time when users obtain suitable cutting parameters through the Internet based platform,a case-based reasoning framework is proposed.Specifically,a Hamming distance and Euclidean distance combined method is designed to measure the similarity of case features which have both numeric and category properties.In addition,AHP(Analytic Hierarchy Process)and entropy weight method are integrated to provide features weight,where both user preferences and comprehensive impact of the index have been concerned.Grey relation analysis is used to obtain the similarity of a new problem and alternative cases.Finally,a platform is also developed on Visual Studio 2015,and a case study is demonstrated to verify the practicality and efficiency of the proposed method.This method can obtain cutting parameters which is suitable without iterative calculation.Compared with the traditional PSO(Particle swarm optimization algorithm)and GA(Genetic algorithm),it can obtain faster response speed.This method can provide ideas for selecting processing parameters in industrial production.While guaranteeing the characteristic information is similar,this approach can select processing parameters which is the most appropriate for the production process and a lot of time can be saved.

Spatiotemporal evolution and influencing factors of urban resilience in the Yellow River Basin,China

The Yellow River Basin of China is a key region that contains myriad interactions between human activities and natural environment.Industrialization and urbanization promote social-economic development,but they also have generated a series of environmental and ecological issues in this basin.Previous researches have evaluated urban resilience at the national,regional,urban agglomeration,city,and prefecture levels,but not at the watershed level.To address this research gap and elevate the Yellow River Basin’s urban resilience level,we constructed an urban resilience evaluation index system from five dimensions:industrial resilience,social resilience,environmental resilience,technological resilience,and organizational resilience.The entropy weight method was used to comprehensively evaluate urban resilience in the Yellow River Basin.The exploratory spatial data analysis method was employed to study the spatiotemporal differences in urban resilience in the Yellow River Basin in 2010,2015,and 2020.Furthermore,the grey correlation analysis method was utilized to explore the influencing factors of these differences.The results of this study are as follows:(1)the overall level of urban resilience in the Yellow River Basin was relatively low but showed an increasing trend during 2010–2015,and significant spatial distribution differences were observed,with a higher resilience level in the eastern region and a low-medium resilience level in the western region;(2)the differences in urban resilience were noticeable,with industrial resilience and social resilience being relatively highly developed,whereas organizational resilience and environmental resilience were relatively weak;and(3)the correlation ranking of resilience influencing factors was as follows:science and technology level>administrative power>openness>market forces.This research can provide a basis for improving the resilience level of cities in the Yellow River Basin and contribute to the high-quality development of the region.

Application of combination weighting method in contract risk's evaluation of third party logistics

First,the analytical hierarchy process(AHP),which stands for the subjective weighting method,and the entropy method,which stands for the objective weighting method,are chosen to calculate the index weights of the contract risks of third party logistics(TPL),respectively.Then,they can determine the combination weights using the combination weighting method.Second,using the combination weights,the contract risks of TPL are evaluated through the fuzzy comprehensive evaluation method.According to the combination weights,the most important risk factor of the contract risks of TPL is choosing sub-contractors.The results are basically consistent with the facts and show that the weights determined by the combination weighting method can avoid the man-made deviations of the subjective weighting method on the one hand,and prevent results opposite to the reality brought about by the objective weighting method on the other hand.Meanwhile,the results of the fuzzy comprehensive evaluation are that the contract risks of TPL are at a high risk level.Roughly this matches real situations,and it indicates that the combination weighting method can generate the comprehensive assessment more scientifically and more reasonably as well.

多场景下基于AHP-EWM的人体健康状态评估模型研究

为解决人体健康评估方法个性化监测不足的问题以及在满足不同场景下健康状态精细化评估的需求,需要一种基于多场景的人体健康状态评估方法来实现长期自动化监测。提出一种基于层次分析法(AHP)和熵权法(EWM)组合的多场景人体健康状态评估模型。首先采集人体在运动、休息、工作/学习和娱乐等4种不同场景下的健康监测指标数据,构建相应的评估指标体系。然后分别根据评估指标计算出AHP和EWM权重,再采用量子粒子群优化(QPSO)算法对AHP和EWM中的主客观权重进行分配,以确保评价指标占比的客观性。最后通过模糊综合评价法对人体健康状态进行评估和量化,并利用实际监测数据对方法的可靠性和稳定性进行验证。实验结果表明,在4种场景下所提方法的综合得分分别为63.78、59.83、58.71和59.21,表明在不同场景下该模型都具有较好的准确性和稳定性。根据评估结果,对测试者的身体状态评价结果进行分析,并给出一些健康建议。所提模型可全面了解人体在不同场景下的健康状况,并为人们提供科学的健康指导,从而为健康管理和疾病预防提供科学依据。

基于AHP-熵权-可拓学的高校建筑电气节能评价

针对高校能源消耗过高以及浪费严重的问题,提出了一种基于层次分析法、熵权法与可拓学理论融合的高校校园建筑电气节能评价模型。运用可拓学理念,给出了用于评估电气节能性能的物元模型;建立电源节能、电网节能、负荷节能、建筑体系节能为准则的评价体系,选取12个评价指标并引入层次分析法与熵权法计算各评价指标的权重;结合所建立的物元模型构建经典域、节域完成关联度计算。以某高校为例,利用所构建的评价模型完成对其建筑电气节能空间的评价,得到该高校校园建筑电气节能空间为中等级别,其级别特征值为2.90,结果表明其仍存在较大的节能空间,最后根据评价结果提出相应的改进措施。

基于AHP-Entropy综合权重法的航空四站装备保障安全评价

针对航空四站装备保障安全评价问题,提出了基于层次分析法和熵权法的综合权重模糊评价模型。在构建航空四站装备保障安全评价指标体系的基础上,综合利用层次分析法、熵权法的优点,改进了权重确立方法。该方法将影响因素的主观性与客观性相结合,得出各指标综合权重。通过模糊综合评价法对某航空四站装备保障实例分析,结果表明该权重确立法客观合理,可为航空四站装备保障风险控制提供判断依据。

基于D-S证据理论改进AHP-熵权的流域洪涝灾害评估研究

考虑致灾因子危险性、孕灾环境敏感性以及承灾体易损性,选取指标构建小清河流域洪涝灾害风险评估指标体系,提出一种基于D-S证据理论的改进AHP-熵权法计算指标权重,求取洪涝灾害风险指数,运用自然断点分级法确定洪涝灾害风险等级,分析小清河流域洪涝灾害风险空间分布情况。结果表明:小清河流域洪涝灾害风险总体上表现出南低北高的趋势,其中高风险区和较高风险区分别占流域面积的8.7%和14.3%,主要分布在小清河干流以及主要支流两岸。所得评估结果同“利奇马”台风发生期间实际洪灾风险分布情况一致,对比证明基于D-S证据理论的改进AHP-熵权法优于AHP和熵权法,可为小清河流域防洪减灾决策提供依据。

基于AHP—熵权法的甘肃省营商环境评价与优化研究

以甘肃省为对象,通过对甘肃省优化营商环境的政府文件进行文本分析,提取评价指标,结合文献以及甘肃省情补充指标后,创新性运用层次分析法(AHP)与熵权法(EWM)进行组合赋权,最终构建出以市场环境、政务数字环境、法制政策环境、创新环境、基础建设环境、生态环境为指标的甘肃省营商环境评价体系,代入甘肃省14个市州的指标数据后,对甘肃省各市州和甘肃省总体营商环境进行分析,为甘肃省营商环境的优化提供了科学依据和建议。

基于AHP-熵权的装配式建筑全过程安全风险与应对策略研究

为有效提炼出装配式建筑全过程安全风险的关键风险因素,探究其可持续发展方向和路径,提出基于熵权法和层次分析法(AHP)相结合的装配式建筑全程安全风险测量方法,并选择6个一级指标和主要的21个二级指标,构建了装配式建筑全过程安全风险评价指标体系,计算出各一、二级指标的相对权重与综合权重,研究得出:技术风险对装配式建筑全过程安全影响最大,影响权重为0.2707,其次是设备与材料风险(0.1927),第三是管理风险(0.1889),人为因素风险(0.1477),环境风险(0.1078),影响最小的是外部因素风险(0.0924)。最后针对评价结果提出针对性应对策略。

AModel for the Optimization of the Shale Gas HorizontalWell Section Based on the Combination of Different Weighting Methods in the Frame of the Game Theory

Existing“evaluation indicators”are selected and combined to build a model to support the optimization of shale gas horizontal wells.Towards this end,different“weighting methods”,including AHP and the so-called entropy method,are combined in the frame of the game theory.Using a relevant test case for the implementation of the model,it is shown that the horizontal section of the considered well is in the middle sweet spot area with good physical properties and fracturing ability.In comparison with the FSI(flow scanner Image)gas production profile,the new model seems to display better abilities for the optimization of horizontal wells.

Construction and Application of Combined Evaluation Model of Regional Water Quality Plan

[Objective] The aim was to study the construction and application of combined evaluation model of regional water quality plan. [Meth- od] By dint of layer analysis, subjective and objective model of entropy evaluation, the water quality plan in Jinghe was evaluated. Combined evalu- ation model based on information entropy were constructed, and considering the single model evaluation result, the optimal water quality plan was selected. [ Result] The combination weight result suggested that COD amount was the most essential indicator in water quality plan and embodied the importance of water environment protection, which met basic objective of environment protection and social, economic effects. Combined evalu- ation indicated that in the sixteen plans, plan 16 was of highest comprehensive evaluation value, and can be considered as optimum water quality plan. [ Conclusion] Combined evaluation model can effectively list the advantages of each evaluation model and improve the dependability of water quality plan, and provided a new research idea for the optimal evaluation of water pollution control plan.

基于AHP熵权TOPSIS模型的矸石充填方案评价和优选研究

煤矸石井下充填是近年来发展起来的矸石绿色处置方法,但不同的充填开采工艺并没有相关的标准、规范,尚未建立完善的评价体系。依据《煤矿充填开采工作指导意见》,针对陕北生态脆弱区本地特点,根据陕西小保当矿业有限公司矸石充填施工方案,提出了基于多因素指标构建的煤矸石充填评价体系。为了使评价指标权重分配合理,采用层次分析法和熵权法相结合的主客观综合赋权法,在兼顾到陕北地区生态环境突出问题的同时减少主观性,使赋权结果科学、合理。最后,将组合赋权结果运用到TOPSIS模型进行决策分析,科学评判出最优施工方案,最终认为地面钻孔充填为最优方案,并实施了200万t/a的煤矸石充填实例进行验证,得出了煤矸石充填的综合成本值。

基于AHP-熵权法的望虞河西岸圩区活水调度方案多目标优选

以望虞河西岸的甘露圩和荡北圩为研究区,构建水动力-水质模型,选取恰当的水动力、水质和经济成本指标构建活水调度多目标评价指标体系,采用层次分析法和熵权法主客观相结合确定指标权重,决策单圩活水调度最优方案,并与圩区联合调度方案比较活水调度效果。结果表明:利用多目标评价指标体系可有效确定活水调度最优方案;甘露圩最优调度方案为陈家角闸和甘露港闸共同引水,徐家浜闸站以6 m^(3)/s流量抽排;荡北圩最优调度方案为黄塘河闸和五星河北闸引水,珠桥河闸站和五星河闸站共以9 m^(3)/s流量抽排;与单圩活水调度相比,两圩联合调度后畅流活水效果更优。

基于AHP-熵权法的输变电工程低碳评价体系及方案优选

“双碳”目标要求下,输变电工程项目向节能减碳方向发展势在必行。为掌握输变电工程减碳与成本及效益之间的本征关系,建立输变电工程成本效益评价指标体系。运用层次分析法(analytic hierarchy process,AHP)确定各项指标对成本及效益的影响权重,再采用熵权法对指标权重进行标准化及客观化修正,之后对每种技术方案选取1000个采样点进行敏感性分析,从而建立起较为完善的输变电工程综合评价体系。基于所建立的指标体系与数学模型对110 kV和220 kV案例进行分析,所得准则层与指标层误差均不足10%。随后提出8种备选减碳方案,逐一计算该8种方案全生命周期净现值与现金流,并对方案综合评分。最终得出结论:准则层中权重占比最高的为“新型变压器”技术,指标层中权重占比最高的为“变压器负载损耗”,且依据方案7改造有望以较低成本实现较高效益。

基于专利特征的人工智能领域核心技术识别及发展趋势分析——层次分析(AHP)-熵权法

人工智能是新一轮产业变革的核心驱动力,为助力中国人工智能产业实现核心技术突破,构建识别人工智能领域核心技术的方法并分析其现状。以智慧芽专利数据库收录的2000—2020年人工智能领域专利为数据源,从地域、申请人和国际专利分类号(IPC)层面分析人工智能领域技术的分布和发展情况;构建涵盖技术、法律和经济三维度的核心专利识别指标体系,基于层次分析(AHP)-熵权法的核心识别模型进行人工智能领域的核心技术识别。结果发现:世界人工智能技术正处于快速增长期,逐渐形成以企业主导技术创新模式;中国在体量和应用多元化上有所突破,但发展不均衡,核心技术研发存在一定短板;识别得到的14项核心技术均为美国持有,集中在语音识别、通信传输、电数据处理、图像分析技术领域,美国在人工智能产业领域占据主导地位,技术研发重心逐渐扩散,已经涉及医疗、交通、物流以及金融、工业等各个产业领域。所筛选出的核心专利符合世界人工智能技术领域发展现状,证明基于专利属性特征构建的三维核心技术识别模型具有一定的科学性和有效性。最后基于研究结论,从政府、企业和研发方向等方面对中国人工智能发展提出建议。

基于AHP-熵权法的天麻共生蜜环菌质量评价研究

目的采用层次分析(AHP)-熵权法综合评价天麻共生蜜环菌质量。方法将采集到的6株天麻共生蜜环菌菌株的生理、生长、化学指标作为评价因子,通过AHP-熵权法计算各指标权重系数,构建综合质量评价体系,对蜜环菌菌株进行质量评估,并通过红天麻、杂交天麻伴播试验进行验证。结果质量评价结果显示,胞外木聚糖酶活性、胞外纤维素酶活性、总糖含量权重较大,其中菌株N6、N3排名靠前。不同变型天麻伴播试验显示,菌株N5、N4伴播红天麻效果较好,菌株N6、N3伴播杂交天麻效果较好。结论蜜环菌的胞外木聚糖酶活性、纤维素酶活性和总糖含量等指标与伴播天麻的效果相关性较强。本研究构建的质量评价体系与杂交天麻伴播试验结果基本一致,可为天麻优良共生蜜环菌的筛选提供参考。