Evaluation of soil erosion vulnerability in Hubei Province of China using RUSLE model and combination weighting method

Soil erosion has been recognized as a critical environmental issue worldwide.While previous studies have primarily focused on watershed-scale soil erosion vulnerability from a natural factor perspective,there is a notable gap in understanding the intricate interplay between natural and socio-economic factors,especially in the context of spatial heterogeneity and nonlinear impacts of human-land interactions.To address this,our study evaluates the soil erosion vulnerability at a provincial scale,taking Hubei Province as a case study to explore the combined effects of natural and socio-economic factors.We developed an evaluation index system based on 15 indicators of soil erosion vulnerability:exposure,sensitivity,and adaptability.In addition,the combination weighting method was applied to determine index weights,and the spatial interaction was analyzed using spatial autocorrelation,geographical temporally weighted regression and geographical detector.The results showed an overall decreasing soil erosion intensity in Hubei Province during 2000 and 2020.The soil erosion vulnerability increased before 2000 and then.The areas with high soil erosion vulnerability were mainly confined in the central and southern regions of Hubei Province(Xiantao,Tianmen,Qianjiang and Ezhou)with obvious spatial aggregation that intensified over time.Natural factors(habitat quality index)had negative impacts on soil erosion vulnerability,whereas socio-economic factors(population density)showed substantial spatial variability in their influences.There was a positive correlation between soil erosion vulnerability and erosion intensity,with the correlation coefficients ranging from-0.41 and 0.93.The increase of slope was found to enhance the positive correlation between soil erosion vulnerability and intensity.

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.

Comprehensive evaluation of the transformer oil-paper insulation state based on RF-combination weighting and an improved TOPSIS method

The accurate identification of the oil-paper insulation state of a transformer is crucial for most maintenance strategies.This paper presents a multi-feature comprehensive evaluation model based on combination weighting and an improved technique for order of preference by similarity to ideal solution(TOPSIS)method to perform an objective and scientific evaluation of the transformer oil-paper insulation state.Firstly,multiple aging features are extracted from the recovery voltage polarization spectrum and the extended Debye equivalent circuit owing to the limitations of using a single feature for evaluation.A standard evaluation index system is then established by using the collected time-domain dielectric spectrum data.Secondly,this study implements the per-unit value concept to integrate the dimension of the index matrix and calculates the objective weight by using the random forest algorithm.Furthermore,it combines the weighting model to overcome the drawbacks of the single weighting method by using the indicators and considering the subjective experience of experts and the random forest algorithm.Lastly,the enhanced TOPSIS approach is used to determine the insulation quality of an oil-paper transformer.A verification example demonstrates that the evaluation model developed in this study can efficiently and accurately diagnose the insulation status of transformers.Essentially,this study presents a novel approach for the assessment of transformer oil-paper insulation.

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.

Engineering Geological Zoning of Soft-Soil Foundation Based on Combination Weighting and Extension Methods

Different criteria and factors are used in different methods of soft soil foundation settlement calculation and engineering geological zoning.The methods used are not universally suitable for complex geological environments.The post-construction settlement of soft soil foundations are especially large and difficult to calculate.In addition,there are many deficiencies in the current methods used for engineering geological zoning.Focusing on the need of establishing engineering geological zoning for areas with soft soil foundations in the Tianjin Marine Economic Area,combination weighting and extension methods were introduced.An evaluation model for the settlement of soft soil foundations was established using multiple factors and large amounts of data.This evaluation model is accurate and objective for delineating engineering geological zoning.These methods eliminate deficiencies by considering both objective and subjective factors,and help obtain an objective and accurate result.

Nonlinear combined forecasting model based on fuzzy adaptive variable weight and its application

In order to enhance forecasting precision of problems about nonlinear time series in a complex industry system,a new nonlinear fuzzy adaptive variable weight combined forecasting model was established by using conceptions of the relative error,the change tendency of the forecasted object,gray basic weight and adaptive control coefficient on the basis of the method of fuzzy variable weight.Based on Visual Basic 6.0 platform,a fuzzy adaptive variable weight combined forecasting and management system was developed.The application results reveal that the forecasting precisions from the new nonlinear combined forecasting model are higher than those of other single combined forecasting models and the combined forecasting and management system is very powerful tool for the required decision in complex industry system.

基于IAHP-EWM博弈论的煤层底板突水影响因素研究

为了研究影响底板突水的水文地质和管理因素,利用文献调研法确立了6个一级指标和20个二级指标的层次分析模型;收集8例突水事故指标数据,根据事故发生经过和事故原因分析,采用1~9标度体现人员管理因素指标对事故发生概率和后果的影响程度;利用区间层次分析法(IAHP)和熵权法(EWM)对所收集数据进行分析,利用博弈论对所确立指标进行组合赋权。研究结果表明,水文地质因素方面隔水层厚度和含水层水压权重最高,在管理因素方面地质基础资料不足是影响突水的关键因素,通过与其他类似研究对比,指标权重计算排序结果具有一定合理性,为研究底板突水提供方法参考,为煤层底板突水的精确防治和管理提供借鉴。

基于FAHP-EWM组合权重的突水危险性评价研究

通过统计分析吴堡矿区某井田先期开采地段地质及水文地质资料,确定影响主采煤层底板突水的主控因素,采用模糊层次分析法(FAHP)和熵权法(EWM)计算各因素的主客观权重,并利用加法合成法、极差最大化法、博弈论法和最小鉴别信息法分别计算组合权重;结合脆弱性指数法,利用GIS的信息融合技术得到研究区的突水脆弱性评价分区,4种评价结果的分区过渡趋势基本一致,但存在部分区域其评级结果不同。采用Spearman等级相关系数对4种突水脆弱性评价结果进行优选,结果表明:基于最小鉴别信息法得到的脆弱性指数等级排序与“合理排序”的相关系数最高;在这4种脆弱性评价结果中,采用最小鉴别信息法组合赋权得到的突水脆弱性评价效果最好。

Synthetic Evaluation of Steady-state Power Quality Based on Combination Weighting and Principal Component Projection Method

With integration of renewable energy and use of non-linear loads in power systems,the power quality problem is increasingly attracting attention of researchers.In China,standards for individual power quality indexes are set.However,when evaluating power quality in practice,individual indexes cannot directly reflect a comprehensive level of power quality.In this paper,a comprehensive analysis of various indexes is conducted to obtain a unified parameter for describing the characteristics of power quality from an overall perspective.First,weight values of power quality indexes are calculated by combining the subjective and objective weight.Then,based on the principal components of the projection method,projection values of boundary data and data to be evaluated are obtained.Finally,using these projection values,a grade range for power quality data is located.A practical case study is presented to show the validity of the proposed method for evaluating power quality.

Safety Evaluation Method for Long-Term Operation of Metro Based on Combination Weighting Method

Metros are critical infrastructure in big cities and evaluation of their safe operation is of increasing im-portance.To make a reasonable safety evaluation for the metro during operation,this paper establishes a rational safety evaluation model based on long-term monitoring data of Shanghai Metro Line 2.Four evaluation indicators,ie.,absolute settlement,relative curvature,deformation rate and curvature radius,are adopted.Analytic hierar-chy process(AHP)and entropy method are combined to determine the weights of the indicators.The risk level values at different mileage are calculated and five danger levels are defined accordingly to determine the safety state of Shanghai Metro Line 2,ie.,safe,relatively safe,critical,relatively dangerous,and dangerous.Safety evaluation of Shanghai Metro Line 2 shows that:83.81%areas of Shanghai Metro Line 2 are in safe,relatively safe and critical states,while 15.63%and 0.57%areas are in relatively dangerous and dangerous states,respectively;the parts of Shanghai Metro Line 2 where the risk level values exceed the critical value are mainly distributed around the mileage at 6.0-7.5km and 8.5-11.0 km,and the risk level value peaks around the mileage at 7.3km,to which much attention should be attached and relevant protective measures be taken;the sections with the high risk level values coincide with the distinctly deforming arcas of the metro,indicating that this evaluation method is valid.

Spatial diversity and combination technology using amplitude and phase weighting method for phase-coherent underwater acoustic communications

The UWA channel is characterized as a time-dispersive rapidly fading channel, which in addition exhibits Doppler instabilities and limited bandwidth. To eliminate inter- symbol interference caused by multipath propagation, spatial diversity equalization is the main technical means. The paper combines the passive phase conjugation and spatial processing to maximize the output array gain. It uses signal-to-noise-plus-interference to evaluate the quality of signals received at different channels. The amplitude of signal is weighted using Sigmoid function. Second order PLL can trace the phase variation caused by channel, so the signal can be accumulated in the same phase. The signals received at different channels need to be normal- ized. It adopts fractional-decision feedback diversity equalizer （FDFDE） and achieves diversity equalization by using different channel weighted coefficients. The simulation and lake trial data processing results show that, the optimized diversity receiving equalization algorithm can im- prove communication system＇s ability in tracking the change of underwater acoustic channel, offset the impact of multipath and noise and improve the performance of communication system. The performance of the communication receiving system is better than that of the equal gain combination. At the same time, the bit error rate （BER） reduces 1.8%.

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.

考虑保供电需求的光储微电网优化配置及电能质量评估

针对用户日益迫切的保供电需求以及光伏出力与负荷用电的随机性、波动性引发的电能质量的问题,建立了考虑保供电需求的光储微电网双层优化模型,并对规划配置的微电网电能质量进行评估。该模型以等效净负荷标准差和弃光率最小为上层优化目标,以微电网有功功率损耗最小为下层优化目标,以储能满足保供电负荷的保供电需求作为附加约束条件,采用遗传算法求解。然后设计源、网、荷三类指标,采用组合赋权法确定各指标权重,实现对微电网电能质量的综合评估。最后以改进的IEEE-33系统验证了所提模型的有效性。结果表明考虑保供电需求后能够提高微电网电能质量,并在一定范围内保供电负荷越大时越能提高微电网电能质量和用户满意度。

组合赋权法在卷烟机综合性能评价中应用

【目的】客观准确地评价卷烟机设备性能,从质量水平、消耗水平和效能水平3个维度出发,构建设备综合性能评价指标体系和组合赋权评价模型。【方法】利用最大熵原理给出最优组合系数和方案评价计算步骤。开展Topsis方法、层次分析法、熵值法和组合赋权法在卷烟机设备综合性能评价的实例分析和比较工作。【结果】4种方法具有显著正相关关系,评价结果满足一致性。组合赋权法与其他评价方法相比具有最优组合系数和误差平方和小优势。

湖北省城市雨涝灾害韧性的时空演变及障碍因子

为探讨湖北省城市雨涝灾害韧性的时空演变及障碍因子,构建包含经济、社会、基础设施和生态环境4维度韧性评价指标体系,采用组合权重TOPSIS法测度韧性水平,结合GIS空间分析方法探究其时空演变特征,运用障碍度模型对评价结果进行障碍因子诊断。研究结果表明:湖北省城市雨涝灾害韧性整体呈上升趋势,各城市间韧性指数差异程度有所减小,韧性水平趋向均衡化发展;湖北省城市雨涝灾害韧性呈现“东西强、中间弱”空间分布格局,全局不存在显著的空间集聚性;单位面积泵站数量、万人在校大学生数、公共安全财政投入比、排水管道密度和人均GDP是制约湖北省城市雨涝灾害韧性的5大主要障碍因子。研究结果可为湖北省制定区域洪涝灾害管理政策及韧性城市规划提供参考。

基于VMD-改进最优加权法的短期负荷变权组合预测策略

为提升短期电力负荷预测精度,提出了一种变权组合预测策略。首先,为了降低负荷数据的不平稳度,使用变分模态分解(variational mode decomposition,VMD)将负荷数据分解成了高频、低频、残差3种特征模态分量。其次,充分计及负荷数据的时序特点,参考指数加权法原理设计自适应误差重要性量化函数,并结合组合模型在时间窗口内的历史负荷数据的均方预测误差设计改进最优加权法的目标函数和约束条件,以完成子模型的准确变权。最后,针对波动较强的高频分量选定极端梯度提升(XGBoost)和卷积神经网络-长短期记忆(CNN-LSTM)模型并使用改进最优加权法进行组合预测、低频分量使用多元线性回归(MLR)模型预测、残差分量使用LSTM模型预测,叠加各模态分量的预测结果,实现了短期负荷数据的准确预测。实验结果表明,使用策略组合模型的平均绝对百分比误差为4.18%。与使用传统组合策略的组合模型相比,平均绝对百分比预测误差平均降低了0.87%。

水利工程施工的IT2FS-MARCOS风险评价

为解决专家决策的主观性造成的风险评价不确定性和不同风险参数权重下考虑多种风险因子评价问题,这里提出一种基于IT2FS-MARCOS法的水利工程施工风险评价方法。首先确定水利工程施工风险指标评估体系,运用最优最劣法(BWM)融合基于层间相关性的客观赋权法(CRITIC)的组合赋权法对各风险参数的权重进行分析;然后引入区间2型模糊集(IT2FS)改进多准则决策中的基于折衷方案的备选方案排序法(MARCOS)计算各风险因素的效用函数值,基于效用函数值进行风险因素分析和评价。结合工程实例应用,表明:地质、天气条件和作业计划安排等风险因素危险程度较高,其中地质条件对该施工项目安全威胁最大,为水利工程施工需重点管理的风险因子。该模型的特点是不仅考虑了专家评价的模糊性,而且采用多准则决策方法避免对风险参数简单加权,与优劣解距离法(TOPSIS)相比,本方法与工程实际符合得更好,有望为处理水利工程不确定信息下的风险评价提供一种新的思路。

土石坝运行安全评价的改进组合赋权-云模型

针对土石坝运行安全评价中指标间相互影响、主客观权重赋值不够合理以及隶属区间模糊性等问题,提出了一种土石坝运行安全评价的改进组合赋权-云模型。以运行期土石坝为对象,构建了土石坝安全评价指标体系,分别采用G1法和改进熵权法对评价指标进行主客观赋权,融合博弈论思想求解最优权重组合系数,并引入云模型理论降低评价过程中隶属区间的模糊性。对某土石坝安全状态进行评价并与两种传统组合赋权法进行了对比,结果表明,3种评价方法的评价结果相近且与实际情况相符,但改进组合赋权-云模型考虑了评价指标间的关联性,运用博弈论思想使主客观权重赋值更加合理,能更客观地反映土石坝的真实运行状态。

改进雷达图法在高校宿舍火灾风险评估中的应用

由于高校宿舍人员高度密集,一旦发生火灾其极易造成严重后果,因此高校宿舍火灾问题亟待重视。为合理评估该风险,首先,借助文献从人、物、环境、管理四方面建立评价指标体系及评价量表;其次,运用合作博弈法将主观赋权结果和客观赋权结果相结合以对评价指标进行组合赋权;随后,将指标权重集转换成各指标轴夹角并计算各指标取值;最后,将经火灾风险雷达图平均周长与同面积圆周长之比为短板系数进行修正的雷达图平均面积作为评价特征量建立高校宿舍火灾风险评价方法。该方法可避免人为赋权的主观性且能以图形形式直观显示出风险管控环节中的薄弱环节。最后以某一实例验证了该评价方法的有效可行性,可为高校宿舍火灾风险评价提供新的思路。

基于地铁车轮型面动态变化下轮轨界面综合摩擦系数优化

针对车轮型面动态变化下的轨顶/轨侧摩擦系数匹配问题,跟踪测试2条线路在不同服役阶段下的车轮磨耗型面数据,建立地铁车辆动力学模型,分析车轮型面动态变化下轨顶/轨侧摩擦系数匹配对轮轨磨耗性能、轮对冲角、表面疲劳指数和脱轨系数的影响;以上述4个指标建立基于熵权TOPSIS法的多目标优化模型,得到轨顶/轨侧摩擦系数最佳匹配策略。研究发现:随车轮型面动态变化,轮缘磨耗型面和踏面磨耗型面的轮轨接触点发生不同程度的跳跃与集中,轮轨匹配关系恶化;轮缘磨耗型面在服役初期的综合性能主要受轨顶摩擦系数影响,随服役里程增加,轨侧摩擦系数的变化占据主导地位;踏面磨耗型面的综合性能指标主要受轨顶摩擦系数的影响;在车轮服役初始阶段、磨损早期、磨损中期、磨损晚期阶段,轮缘磨耗型面车轮对应的轨顶/轨侧最佳摩擦系数匹配分别为0.30/0.10、0.25/0.10、0.20/0.10和0.20/0.10,踏面磨耗型面车轮对应的轨顶/轨侧最佳摩擦系数匹配分别为0.20/0.15、0.20/0.30、0.20/0.35和0.30/0.15。