太阳质子耀斑引发旱涝灾害的模糊预测

运用模糊数学理论，考虑太阳质子耀斑爆发，对旱涝灾害进行预测。提出了模糊评判指标体系、评价标准及隶属函数公式，研究实用计算机数据处理软件，对洪涝灾害预测提供了依据。     

Fuzzy综合评判在森林水文效应研究中的应用

本文应用多层次、二型Fuzzy综台评判方法,对祁连山水源涵养林区的青海云杉林、祁连圆柏林、灌木林和牧坡草地4个不同植被类型进行了森林水文效应的多因子综合评判。结果表明:青海云杉林是该林区涵养水源效应最佳的林型,祁连圆柏林和灌木林次之,牧坡草地不仅蓄水能力差,且有水土流失发生;并提出了各植被类型合理经营的对策,为祁连山水源涵养林的保护、发展和综合利用提供科学依据。     

模糊数学在四川省自然灾害区划中的应用

本文通过对四川省自然灾害分布规律的系统分析,提出其区划的原则和要求,并引入模糊聚类的方法,对四川省自然灾害进行分区划片,目的是为区域规划提供减灾的重点方向。     

Fuzzy assessment of land suitability for scientific research reserves

Evaluating the characteristics of a set of sites as potential scientific research reserves is an example of land suitability assessment. Suitability in this case is based upon multiple criteria, many of which can be linguistically imprecise and often incompatible. Fuzzy logic is a useful method for characterizing imprecise suitability criteria and for combining criteria into an overall suitability rating. The Ecosystem Management Decision Support software combined a fuzzy logic knowledge base we developed to represent the assessment problem with a GIS database providing site-specific data for the assessment. Assessment of sites as a potential natural reserve for the new University of California campus at Merced demonstrates the benefits of fuzzy suitability assessment. The study was conducted in three stages of successively smaller assessment regions with increasingly fine spatial resolution and specificity of criteria. Several sites were identified that best satisfy the suitability criteria for a reserve to represent vernal pool habitat.     

基于层次模糊综合评判法的土地集约利用研究——以河北省永清县为例

土地集约节约利用越来越成为人们关注的问题，对其进行科学评价也成为焦点。通过对永清县乡镇土地集约利用状况的调查，构建了适合乡镇土地集约度评价的指标体系，采用AHP和模糊综合评判相结合的方法对乡镇土地集约度进行了评价。从而得出永清县土地利用集约度状况，为以后的发展提供借鉴依据。     

基于模糊神经网络的水稻农田重金属污染水平高光谱预测模型

以吉林省长春一汽厂附近3块不同重金属污染状况的水稻实验样地为例,通过地面实测获取了水稻的光谱反射率、叶片叶绿素含量、叶片及土壤重金属含量等数据.同时,在分析重金属对水稻叶片叶绿素含量影响的基础上,通过多元逐步回归分析选出对水稻叶片叶绿素含量微小变化指示灵敏的光谱参数作为模型输入层,并将水稻叶片叶绿素含量值作为输出层来表征农田重金属污染胁迫水平,最终建立了用于预测水稻农田重金属污染水平的模糊神经网络模型.结果表明,该模糊神经网络模型预测的水稻重金属污染胁迫水平与实测结果吻合度较高,预测的叶绿素含量值与实测值的拟合度较好(R2=0.985).表明在受重金属污染胁迫的情况下,水稻叶片叶绿素含量微小而复杂的变化可以通过构建模糊神经网络模型很好地模拟出来,从而确定出农田的重金属污染水平.     

水利项目环境影响综合评价

文章研究了模糊综合评价法在水利建设项目综合环境影响评价中的应用,以某水利工程为例建立了项目环境影响评价的指标体系,并对项目环境影响进行了综合评价,同时将建设项目环保措施的落实程度进行环境影响程度对比分析。结果表明,模糊综合评价方法是一种科学合理、简单可行的环境影响评价方法,可以在水利建设项目的环境影响评价中应用推广;同...     

基于熵权法的连云港市入海河流环境健康评价——以蔷薇河为例

建立包含压力-状态-响应要素的指标体系,采用基于熵权的模糊数学评价方法,运用相对隶属度算法评价在快速城市化胁迫下(2000～2007年)连云港市入海河流(以蔷薇河为例)相对健康程度,该方法避免了主观判断河流环境健康标准的不确定性.评价结果表明2000～2007年,连云港市蔷薇河相对健康整体大致呈下降趋势,最优年为200...     

A multivariable model for estimation of vapor cloud explosion occurrence possibility based on a Fuzzy logic approach for flammable materials

In this paper, a new method based on Fuzzy theory is presented to estimate the occurrence possibility of vapor cloud explosion (VCE) of flammable materials. This new method helps the analyst to overcome some uncertainties associated with estimating VCE possibility with the Event Tree (ET) technique. In this multi-variable model, the physical properties of the released material and the characteristics of the surrounding environment are used as the parameters specifying the occurrence possibility of intermediate events leading to a VCE. Factors such as area classification, degree of congestion of a plant and release rate are notably affecting the output results. Moreover, the proposed method benefits from experts' opinions in the estimation of the VCE possibility. A refrigeration cycle is used as the case study and the probability of VCE occurrence is determined for different scenarios. In this study, sensitivity analysis is performed on the model parameters to assess their effect on the final values of the VCE possibility. Furthermore, the results are compared with the results obtained using other existing models.     

An extension to Fuzzy Fault Tree Analysis (FFTA) application in petrochemical process industry

Fault Tree Analysis (FTA) is an established technique in risk management associated with identified hazards specific to focused fields. It is a comprehensive, structured and logical analysis method aimed at identifying and assessing hazards of complex systems. To conduct a quantitative FTA, it is essential to have sufficient data. By considering the fact that sufficient data is not always available, the FTA method can be adopted into the problems under fuzzy environment, so called as Fuzzy Fault Tree Analysis (FFTA). This research extends FFTA methodology to petrochemical process industry in which fire, explosion and toxic gas releases are recognized as potential hazards. Specifically, the case study focuses on Deethanizer failure in petrochemical plant operations to demonstrate the proposed methodology. Consequently, the study has provided theoretical and practical values to challenge with operational data shortage in risk assessment.