Model of generic project risk element transmission theory based on data mining

In order to construct the data mining frame for the generic project risk research, the basic definitions of the generic project risk element were given, and then a new model of the generic project risk element was presented with the definitions. From the model, data mining method was used to acquire the risk transmission matrix from the historical databases analysis. The quantitative calculation problem among the generic project risk elements was solved. This method deals with well the risk element transmission problems with limited states. And in order to get the limited states, fuzzy theory was used to discrete the historical data in historical databases. In an example, the controlling risk degree is chosen as P(Rs≥2) ≤0.1, it means that the probability of risk state which is not less than 2 in project is not more than 0.1, the risk element R3 is chosen to control the project, respectively. The result shows that three risk element transmission matrix can be acquired in 4 risk elements, and the frequency histogram and cumulative frequency histogram of each risk element are also given.

Analysis and evaluation of enterprise risk management capability elements

Research on enterprise risk management capability is conducted with a view of discerning and processing risks, in which an evaluation index system and an evaluation model of enterprise risk management capabilities are constructed. The risk management capability consists of four aspects, i.e. risk identification capability, risk assessment capability, risk planning capability and risk control capability. Risk identification and assessment capabilities reflect the level of enterprises on finding and analyzing risks efficiently, while risk planning and control capabilities reflect the level of enterprises on resolving risks effectively. Each of capabilities is then further divided into more detailed elements based on the characteristics of enterprise development for a quantitative analysis of enterprise risk management capability. The approach adopted is a quantitative technique based on the use of fuzzy comprehensive evaluation. Finally, a case is pulled in to illustrate the feasibility of the method from an empirical perspective. This study is expected to be helpful for enterprises in cultivating their core capabilities.

Co-Contamination of Arsenic and Other Trace Elements (Hg, Pb, Al, Fe, Cr, Ni, and Cd) in the Rafsanjan Plain Alluvial Aquifer SE of Iran and Arsenic Risk Assessment

Assessing the concentration of trace elements in aquifers is increasingly subjected to study in Iran due to the lack of groundwater resources. This study was undertaken with the objective of determining trace elements in the alluvial aquifer located in the southern part of the Rafsanjan plain, Kerman province, Iran. The total of 73 groundwater samples from individual water wells were analyzed by atomic absorption spectroscopy (AAS). Results showed that the levels of As, Hg, Pb, Al, Fe, Cr, Ni, and Cd elements were above the World Health Organization standards for drinking-water in some parts of the plain. Thus, statistical data analyses and spatial distribution interpretation were performed to identify the main sources of the pollution. A health risk assessment model derived from US environmental protection agency was applied to calculate the cumulative exposure to As as well as toxic and carcinogenic risks caused by drinking contaminated raw groundwater. Results show that residents of some part of region may suffer from significant adverse toxic health impacts and are exposed to drinking water with As concentrations.

Dietary exposure estimates of trace elements in selected agricultural products grown in greenhouse and associated health risks in Korean population

This study focuses on the dietary exposure of trace elements (TEs) through the intake of various agricultural products grown in greenhouse, and its corresponding health risks at different age categories in Korean population. It was observed that the mean contents of TEs found in selected agricultural products were well below their guidelines. Mean and 95th percentile intake estimates of TEs were ranged from 0.02 to that considerable attention should be paid to the potential health risks of TEs through intake of various foodstuffs and other exposure pathways.

Effect of Exposure to Trace Elements in the Soil on the Prevalence of Neural Tube Defects in a High-Risk Area of China

Objective Our objective is to build a model that explains the association between the exposure to trace elements in the soil and the risk of neural tube defects. Methods We built a function with different parameters to describe the effects of trace elements on neural tube defects. The association between neural tube defects and trace element levels was transformed into an optimization problem using the maximum likelihood method. Results Tin, lead, nickel, iron, copper, and aluminum had typical layered effects （dosage effects） on the prevalence of neural tube defects. Arsenic, selenium, zinc, strontium, and vanadium had no effect, and molybdenum had one threshold value that affected the prevalence of birth defects. Conclusion As an exploratory research work, our model can be used to determine the direction of the effect of the trace element content of cultivated soil on the risk of neural tube defects, which shows the clues by the dosage effect of their toxicological characteristics. Based on our findings, future biogeochemical research should focus on the direct effects of trace elements on human health.

Distribution, Enrichment and Ecological Risk Assessment of Six Elements in Bed Sediments of a Tropical River, Chottanagpur Plateau: A Spatial and Temporal Appraisal

Distribution and enrichment of six elements (iron, zinc, copper, lead, cadmium and manganese) in surface bed sediments, collected from seventeen selected locations during pre-monsoon and postmonsoon periods, of the tropical Chottanagpur plateau river Subarnarekha along with the ecological risks involved were investigated. Owing to the rich occurrence of mineral resources, the Subarnarekha river basin has a large scale presence of industrial and mining units especially in the Indian State of Jharkhand. An assessment, which involved examining distribution pattern of elements, comparative studies with sediment quality guidelines (SQGs) and geochemical background values and a sequential and integrated index analyses approach (containing contamination factor (CF), pollution load index (PLI), contamination degree (CD), enrichment factor (EF), geo-accumulation index (Igeo) and potential ecological risk index (PERI)), was followed to estimate enrichment and risks of elements in the bed sediments. Sediments collected from areas having abundance of population, industrial conglomerates and mining units recorded elevated element concentrations, which exceeded SQGs, and significantly higher values of CF, CD, PLI, EF, Igeo and PERI. Cadmium demonstrated surprising regularity in its enrichment;contributed most to the ecological risks;and high toxicity risks due to cadmium exceeded 64% of the sites. Moreover, chronic exposures of other elements would also lead to similar ecological risks. In addition to revealing potential ecological risks due to cadmium and other elements our investigation markedly highlighted anthropogenic control over sediment quality deterioration and some immediate sediment quality management strategies are needed to remediate and control river bed contamination.

基于ICP-MS技术的六神曲中无机元素分析及其风险评估

对六神曲中无机元素进行分析并结合风险评估,为发酵类中药中有益元素的揭示、有害元素限量标准的制定提供依据。基于电感耦合等离子体质谱(ICP-MS)技术,对不同来源六神曲中无机元素进行含量测定,结合多元统计分析,对无机元素的特征进行表征,并对其进行初步风险评估。结果表明:六神曲中无机元素整体趋势一致,对比相关标准产六神曲生品发现,Zn、Ba、Cu为主要差异元素;按部颁标准产六神曲生品与麸炒品差异明显,Zn、Tl、Cu为特征差异元素;Cu、Cr、As为按《浙江省中药炮制规范》产六神曲生品与炒焦品中主要差异元素。风险评估结果提示,六神曲中有害元素的风险较低。方法稳定可靠,不同制法、不同炮制品六神曲中元素分布特征呈现出一定的规律性与差异性,其中重金属及有害元素的风险基本可控。研究结果可为六神曲质量控制体系的完善及安全性评价提供参考。

大数据下企业供应链风险管理与竞争情报融合模型构建--以华为公司为例

[研究目的]国际经贸对抗环境下,中美贸易摩擦将持续升级,国家层面的技术创新竞争使得企业面临的供应链风险大幅提升。同时,大数据改变了供应链风险管理模式,而竞争情报可以从理论、技术和方法等方面提升大数据下企业供应链风险管理能力,因此大数据下企业供应链风险管理与竞争情报的融合研究具有重要意义。[研究方法]采用文献分析、案例研究等方法,分析供应链风险管理与竞争情报的异同点,继而论证大数据下供应链风险管理与竞争情报融合的可行性和必要性,再辅之以标杆企业华为的供应链中断风险事件验证,最终构建大数据下华为供应链风险管理与竞争情报融合模型,并分析运行维护此模型的保障要素。[研究结论]研究表明,基于战略、组织、制度、技术和资源五要素的共同保障,大数据下供应链风险管理与竞争情报的融合能够实现供应链风险管理的全面性、及时性和有效性。

牛黄解毒片中重金属及有害金属元素测定及健康风险评估

目的测定牛黄解毒片中重金属及有害金属元素残留情况,并将风险评估引入中药外源性污染评价。方法样品经微波消解后,采用ICP-MS法对60批牛黄解毒片中重金属及有害金属元素含量进行测定,按照危害识别、危害特征描述、暴露评估和风险描述的程序,对健康风险进行初步评估。结果所测得4种元素在各自范围内线性关系均良好(r≥0.997),回收率为87.3%~93.1%(RSD≤3.1%)。60批样品中Cu﹑Cd﹑Pb均未超标,Hg超标率为48.3%。结论该方法灵敏准确,考察了牛黄解毒片中重金属及有害元素残留情况,科学评估了重金属对人体的健康风险,为中药牛黄解毒片的安全性评价提供研究思路。

山东省胶东半岛养殖刺参中金属元素含量水平分析及健康风险评估

为探讨山东省胶东半岛养殖刺参(Apostichopus japonicus)中铅、镉、汞等11种金属及无机砷含量水平、分布特征及对人体健康的潜在风险,2018—2020年在山东省龙口、莱州、荣城随机采集低播养殖的体质量47.5~98.3 g的刺参样品130份,采用ICP-MS法测定样品中铅、镉、砷等10种元素,原子荧光法测定汞,HPLC-ICP-MS联用法测定无机砷,采用目标危险系数评估样品中金属对人体存在的潜在健康风险,为我国制订鲜海参卫生标准提供参考和数据支撑。结果表明,11种金属元素平均浓度依次递减为Al、Zn、Mn、Cu、As、Cr、Ni、Pb、Cd、Sn、Hg,无机砷含量均小于检出限。单个元素风险顺序为Cd>Cr>Pb>Cu>Al>Zn>Mn>Ni>Hg。单一元素的目标危险系数THQ与多种金属的复合目标危险系数TTHQ均小于1。结果证明:食用山东省胶东半岛养殖刺参目前对人体健康不具有危险性。其中对人体健康危害最大的元素为镉,贡献率达25.6%,应关注海参中镉元素含量对人体健康造成的潜在威胁。

2022年泰州市某区PM_(2.5)中金属元素含量测定及健康风险评价

目的分析2022年泰州市某区大气PM_(2.5)中金属元素的变化特征,评估其对人群的健康风险。方法2022年每月10—16日在监测点进行PM_(2.5)采样,采用电感耦合等离子体质谱法测定12种金属元素含量,利用富集因子(enrich factor,EF)法识别金属元素的来源,并进行人群健康风险评价。结果2022年泰州市某区大气PM_(2.5)中金属元素平均浓度由高到低为Mn>Pb>As>Se>Cr>Ni>Sb>Cd>Hg>Be>Tl,其中Al、Cd、Hg、Ni、Se、Tl浓度变化均有季节性差异(H值分别为13.932、11.817、15.836、8.423、7.876、14.316,P值圴<0.05);Cr、As、Sb、Cd等金属的EF值均>10。当人群暴露外环境时间达到3 h/d,Cr对成年男性、成年女性和儿童可能存在致癌风险;当暴露外环境中时间达到5 h/d,As对成年男性、成年女性可能存在致癌风险。结论该地区PM_(2.5)中金属元素主要来自于人为污染,季节性差异较为明显,Cr和As对人群的潜在健康风险较高,需引起重视。

汾河流域地表水金属元素分布特征与健康风险评价

为研究汾河流域地表水中金属污染特征及其健康危害程度,本文采集汾河流域主要支流入河口及干流断面水样39组,检测As、Cu、Pb、Zn、Hg、Ni、Mn、Fe和Co共9种金属元素含量,利用多元统计分析法、水环境健康风险评价模型分析了流域地表水中金属元素分布特征及对成人与儿童产生的健康危害.结果表明,研究区主要超标元素为Hg、Fe和Mn,污染区主要分布于汾河干流中下游和支流.汾河干流上游Fe、Mn、Zn和Co变化幅度较大,中游、下游次之;各支流金属元素含量差异较大.多元统计分析显示,Hg和As主要来源于工业污染及农业污染等;Cu、Pb、Zn、Ni、Co、Fe和Mn来源于工农业生产和交通运输.健康风险评价表明,汾河流域各河段健康总风险为汾河支流>汾河下游>汾河中游>汾河上游,汾河中下游和支流健康风险危害较大,健康风险均为中等;经饮用水途径造成的健康风险儿童是成人的1.15倍,儿童更易受到金属元素的危害;As为支流浍河和昌源河的主要致癌因子;各河段优先控制金属元素为As、Co、Pb、Fe和Hg.

基于六维语义空间的自动驾驶风险评估研究

针对自动驾驶中风险要素提取不充分、风险场景评估鲁棒性低等问题,提出一种基于六维语义空间的风险评估框架,包括基于六维语义空间的风险要素提取和基于知识图谱的风险场景评估。前者构建六维语义空间并将RGB和红外数据映射其中,利用模态间的关联提取丰富的数据特征,以获得显在和潜在的风险要素。后者通过语义角色标注和实体融合将风险要素凝练为知识图谱,并联合节点补全和风险等级函数设计知识图谱推理方法,实现准确的风险评估。仿真结果表明,较现有的MSMatch和iSQRT-COV-Net方法,所提方法在准确率、漏/虚警率和处理时间上均有优势。

AHP-改进物元法在整体钢平台顶升模架体系安全风险评估中的应用

针对整体钢平台顶升模架体系施工安全性的灰色特征,经实地调研及专家评审,建立了整体钢平台顶升模架体系的安全风险评估模型。首先,考虑人员、设备、环境、管理及技术5个方面,选取19个指标构建安全风险评估指标体系;其次,采用层次分析法计算各指标权重,基于改进物元法确定各指标的风险等级,然后将两者向量相乘,以最大隶属度原则确定整体钢平台顶升模架体系的安全风险等级;最后,将所建立的基于层次分析法(Analytic Hierarchy Process, AHP)-改进物元法的安全风险评估模型应用到某超高层工程实例中,并将评估结果与实际施工情况对比分析。研究表明,该评估模型的计算结果合理且准确可靠,可为超高层整体钢平台顶升模架体系的安全管理提供参考。

气象要素与潜在林火风险关联性研究

为探究川西南地区复杂气候与森林火灾之间的关联性,以四川省凉山彝族自治州木里藏族自治县(以下简称“四川省凉山州木里县”)为例,通过局部规模的气象异常值变化,分析了各气象要素与森林火灾的潜在联系性。再通过FWI与FFDI,分析木里县历史火险变化,验证了其与木里县森林火灾的关联性。结果表明:森林火灾发生前后气压、气温、湿度、风速、蒸发量出现不同周期的连续增加(或衰减)。同时,木里县森林火险指数FWI与FFDI呈现出年际震荡且逐渐增大的趋势,且木里县林火频数与FWI的年均相关系数(46.9%)、月均相关系数(80.7%)均大于FFDI(年相关系数38.7%、月相关系数53.1%)。此外,林火风险值出现极端异常还与同期(或同年)发生的气候事件密切相关。因此,气候异常事件所导致的持续高温、低湿、多风的气象条件是森林火险等级快速升高或重大森林火灾事故的本质原因之一。

郑州市2020~2021年大气PM_(2.5)中金属元素污染特征及健康风险评估

目的:分析2020~2021年郑州市两城区大气PM_(2.5)中金属元素的浓度,推测其可能的来源并评估其健康风险。方法:测定2020~2021年郑州市二七区和经开区的PM_(2.5)及其中金属元素的浓度,利用富集因子(EF)法和主成分分析评估金属元素的来源,并根据相关技术指南进行PM_(2.5)中金属元素经吸入途径的健康风险评估。结果:2020~2021年郑州市二七区、经开区的PM_(2.5)浓度分别为50.00(38.00,72.50)、53.00(40.00,74.50)μg/m^(3),两城区各金属元素浓度比较,差异无统计学意义(P>0.05);两城区Mn、Ni的EF值在10~100之间,其余元素的EF值均大于100;两城区均筛选出两个主成分,成分1包括Se、Sb、Pb、Tl、As、Cd、Ni,成分2包括Al、Mn;两城区金属元素的非致癌风险危害商值均小于1,二七区、经开区As的致癌风险分别为2.20×10^(-5)、2.41×10^(-5),Cd的致癌风险分别为1.55×10^(-6)、1.71×10^(-6)。结论:目前郑州市仍然存在大气PM_(2.5)污染情况,其中金属元素As、Cd对人群具有潜在致癌风险。

ICP-MS测定诃子炮制前后无机元素含量及安全性评价

目的:建立诃子生品及清炒、麸煨、砂烫、烘制4种炮制品中26个无机元素的分析方法,对其中重金属及有害元素进行健康风险评估。方法:采用电感耦合等离子体质谱法,以铑和铼为内标,通过标准曲线法测定诃子中的26个元素;采用危害指数(HI)法和暴露限值(MOE)法进行健康风险评估。结果:26个元素的标准曲线线性关系良好,仪器检出限为0.0002~0.4342μg·kg^(-1),加样回收率为83.21%~116.84%。诃子炮制前后无机元素差异明显,部分重金属及有害元素所致健康风险较低。结论:该方法简便、准确,适用于诃子中无机元素的含量测定,为其重金属及有害元素健康风险评估提供了参考。

冰风荷载作用下架空线路脱冰跳跃风险评估方法

本文提出了一种用于评估架空线路在冰风荷载作用下脱冰风险的方法。通过仿真获取不同脱冰模式下的竖向冰跳高度、横向摆幅和端部动态张力的变化数据,进而计算输电线路相间最小间隙、冲击倍数、悬垂线夹最大不平衡张力及耐张绝缘子串的安全系数。结合这些参数,定量分析了放电、断线、线夹损害和绝缘子串损坏的风险,并输出了综合风险评估结果。此外,本研究引入阶跃函数来模拟脱冰和风荷载,提出了计算脱冰线路最小相间隙的新方法。以中国南方某110kV架空线路为例,验证了该方法的有效性。结果显示,C相导线脱冰导致张力大幅下降,竖向跳跃高度和横向摆幅分别达1.84m和11.6m,耐张串和悬垂线夹的不平衡张力分别高达44kN和85kN,暴露出电气和力学方面的风险。该评估与实际事故相符,证明了方法的准确性。

上海汛期极端降雨阈值时空分布与内涝影响评估

汛期极端降雨给城市地区造成了严重的内涝威胁。首先基于近30 a上海逐日降雨数据构建了日极端降雨阈值时间序列,按照汛期降雨类型区分为梅雨期、盛夏期和秋雨期3种降雨时期,该分类的差异通过了统计检验。汛期极端降雨阈值情景表明,上海市汛期极端降雨雨量为盛夏期最大,极端降雨的空间分布与城市中心、郊区的城市化水平以及汛期降雨时期密切相关。研究基于Mike21数值模型构建城市内涝模型,模拟了汛期极端降雨阈值情景。结果表明:在90分位、95分位、99分位阈值情景下,上海郊区的受淹面积占比最大;盛夏期内涝淹没区域则主要聚集于中心城区和上海东南部,最大淹没深度达1.5 m。99分位阈值情景下,承灾体高暴露度(淹没水深>0.15 m)结果显示,道路受淹比例最高,在22%以上,建筑次之,受淹比例在8%以上,耕地受淹比例相对较小,在4%以上。汛期应重点防范99分位极端降雨事件,研究结果可为防汛除涝提供决策支持。

基于模糊贝叶斯网络的钢管桩围堰安全评价研究

为探明施工过程中影响钢管桩围堰事故发生率的主要因素,降低桥梁基础工程的事故发生率,建立FBN与MIDAS模型,对围堰工程进行事前安全风险研究。首先参照条例规范与4M1E原则将主要因素统筹为人、机、料、法、环五大方面,构建起具有普适性的的风险评估指标体系,其中含有5个一级指标和18个二级指标。其次根据因素间的逻辑关系构建贝叶斯网络模型,基于模糊数理论确定根节点的先验概率,后利用Leaky Noisy-OR Gate模型计算出非根节点的条件概率,通过NETICA软件得到因素耦合效应以及主要影响因素,最后依据实际案例建立MIDAS有限元模型进行定量化分析。结果表明,主要影响因素有水流压力、土体稳定性、支护体系稳定性、焊接质量以及安全防护设备配备程度。