基于可变模糊聚类的城镇综合承灾能力评价研究

城镇灾害的多样性、频繁发生与其造成的各种损失和破坏的严重化趋势,已经对城镇经济社会发展构成重大威胁。城镇应对灾害的预测、防御、救助及灾后恢复的综合能力,直接决定了城镇可持续发展的基础和能力。建立了基于城镇社会、经济和环境属性功能的城镇综合承灾能力评价指标体系,运用可变模糊聚类方法,通过指标权重、相对隶属度与聚类中心之间的动态迭代,得到了更为合理的样本城镇的防灾、抗灾、救灾和灾后恢复能力相对比较结果。与已有研究相比,可变模糊聚类在综合评价问题上的数据处理和分析能力更客观和多样化。     

高速公路转换区严重冲突识别与分析

为深入探究高速公路改扩建转换区发生严重冲突的原因,使用高精度雷达采集单车实时状态数据,对单车区间初速度与加速度进行K-means聚类组合.基于聚类组合内的冲突率与路段事故率,采用Pearson系数法确定车辆的严重冲突阈值.融合转换区单车、交通流和道路因素建立二项Logistic模型,分析严重冲突因素的影响程度.结果表明...     

2022年青岛市沿海区域臭氧污染特征及传输影响分析

基于2022年1—12月青岛市沿海区域臭氧（O₃）自动监测数据和气象观测资料,对O₃污染变化特征及影响因素进行了分析,结合后向轨迹聚类与潜在源区分析等方法,对O₃外来输送通道及潜在源分布情况进行分析研究。结果表明：青岛市沿海区域O₃污染主要集中在4—10月份,日变化特征呈单峰单谷趋势,峰值出现在15：00—16：00;气象因素中,地面短波辐射对O₃浓度变化的相对贡献最大,偏南风易导致O₃污染;受二氧化氮（NO₂）滴定作用以及海陆风转换影响,沿海区域O₃峰值与谷值均滞后青岛城区1 h左右;O₃生成整体处于VOCs控制区,1-丁烯、正丁烷与异戊烷是O₃污染期间导致O₃浓度上升的关键组分;O₃污染的主要潜在源区为长三角北部和黄海近岸海域,以及山东中南部地区。     

粉煤灰资源化利用发展战略的研究

运用系统工程原理和运筹学的分析方法,对南京地区粉煤灰资源化利用的发展战略、制约因素及政策措施进行了分析,提出了一些方案措施,为南京市规划、管理和制定用灰政策提供了必要的科学依据。     

基于AHP和灰色聚类的危化品道路运输安全评价

为客观评价危化品道路运输企业安全状况,防止危化品道路运输事故发生,提出基于层次分析法(AHP)和灰色聚类分析的危化品道路运输安全评价方法。首先以危化品与设备情况、环境情况、企业安全管理水平、在途监管水平及人员特性为一级指标构建危化品道路运输安全评价指标体系;其次,运用AHP计算各指标权重;最后,为了避免指标信息不完整所造成的误差,选用灰色聚类分析对各指标进行聚类分析,得出研究对象的安全等级。运用该方法对C企业危化品道路运输安全等级进行评价,评价结果显示该企业安全等级较高,但安全防护设备、交通状况、安全管理制度落实情况等指标安全性较低,同时验证了该方法具有适用性及有效性,为危化品道路运输企业安全评价提供了一种新的方法。     

节段预制悬臂拼装梁施工安全风险评价

为了准确地对节段预制悬臂拼装梁的施工过程进行安全风险评价,对该类桥梁的施工提供有效借鉴,提出基于组合赋权的灰色聚类综合评价模型。首先根据该施工技术的工艺特点及相关规范,建立风险评价指标体系,利用G1法和C-OWA算子分别确定评价指标体系的主观权重和客观权重,并运用最小信息熵原理优化组合赋权,进一步利用三角白化权函数建立灰色聚类评价模型,确定风险综合评价值,最后依据风险测度界定范围判断施工安全风险等级。最后,运用此评价模型进行实例分析,并根据评价结果提出改进策略,同时验证了该模型的适用性和有效性,进而为该类桥梁施工安全风险管控策略的制定提供理论依据。     

Analysis of Extreme Summer Rainfall Using Climate Teleconnections and Typhoon Characteristics in South Korea1

Abstract: It is now widely acknowledged that climate variability modulates the frequency of extreme hydrological events. Traditional methodologies for hydrologic frequency analysis are not devised to account for variation in the exogenous teleconnections. Flood frequency analysis is further plagued by the assumptions of stationary in the causal structure as well as ergodicity. Here, we propose a dynamical hierarchical Bayesian analysis to account for exogenous forcing that govern the summer season rainfall. The precursors for Korean summer rainfall at different frequencies are identified utilizing wavelet and independent component analyses. The sea surface temperatures, the ensemble of rainfall predictions by General Circulation Model, in addition to the typhoon attributes were found to have direct correlation with extreme rainfall events and were used as inputs to the logistic regression model. The model parameters are estimated using Markov Chain Monte Carlo and the resulting posterior distributions associated with individual inputs are analyzed to advance our understanding of the spatiotemporal impact of the teleconnections. Eight rainfall stations throughout Korea are considered in this analysis. We demonstrate that the probability of occurrence of extreme events could be successfully projected at a 90% rate of correct classification of extreme events.     

Evolution of road risk disparities at small-scale level: example of Belgium

PROBLEM: Road accident outcomes are traditionally analyzed at state or road network level due to a lack of aggregated data and suitable analytical methods. The aim of this paper is to demonstrate usefulness of a simple spatiotemporal modeling of road accident outcomes at small-scale geographical level. METHOD: Small-area spatiotemporal Bayesian models commonly used in epidemiological studies reveal the existence of spatial correlation in accident data and provide a mechanism to quantify its effect. The models were run for Belgium data for the period 2000-2005. Two different scale levels and two different exposure variables were considered under Bayesian hierarchical models of annual accident and fatal injury counts. The use of the conditional autoregressive (CAR) formulation of area specific relative risk and trend terms leads to more distinctive patterns of risk and its evolution. The Pearson correlation tests for relative risk rates and temporal trends allows researchers to determine the development of risk disparities in time. RESULTS: Analysis of spatial effects allowed the identification of clusters with similar risk outcomes pointing toward spatial structure in road accident outcomes and their background mechanisms. From the analysis of temporal trends, different developments in road accident and fatality rates in the three federated regions of Belgium came into light. Increasing spatial disparities in terms of fatal injury risk and decreasing spatial disparities in terms of accident risk with time were further identified. IMPACT ON INDUSTRY: The application of a space-time model to accident and fatal injury counts at a small-scale level in Belgium allowed identification of several areas with outstandingly high accident (injury) records. This could allow more efficient redistribution of resources and more efficient road safety management in Belgium.     

防空导弹武器系统伪装能力综合评价研究

针对防空导弹武器系统的暴露特征,采用层次分析法,建立了防空导弹武器系统伪装能力多层次综合评价指标体系和综合评价模型,采用模糊聚类分析法对数据进行处理,得出各评价对象的综合评价结果。最后通过算例,验证了该模型的有效性。     

城市应急避难场所层次布局研究(Ⅱ)——三级层次选址模型

分析应急避难场所层次选址的目标因素:建设成本和避难效果,提出总的移动距离最短和建设成本最小两类选址目标,立足城市发展程度差异和现状应急避难场所建设情况分析,将应急避难场所选址类型分为规划性选址、老城新选址、补充性选址三种。依据应急避难场所的三级层次划分,以及单一流、嵌套、空间非匹配的层次特点,分别建立了应急避难场所的规划性选址、老城新选址、补充性选址共8个三级层次选址模型,并通过模拟实验对模型的效果进行了检验。