Risk Early-Warning Method for Natural Disasters Based on Integration of Entropy and DEA Model

Risk early-warning of natural disasters is a very intricate non-deterministic prediction, and it was difficult to resolve the conflicts and incompatibility of the risk structure. Risk early-warning factors of natural disasters were differentiated into essential attributes and external characters, and its workflow mode was established on risk early-warning structure with integrated Entropy and DEA model, whose steps were put forward. On the basis of standard risk early-warning DEA model of natural disasters, weight coefficient of risk early-warning factors was determined with Information Entropy method, which improved standard risk early-warning DEA model with non-Archimedean infinitesimal, and established risk early-warning preference DEA model based on integrated entropy weight and DEA Model. Finally, model was applied into landslide risk early-warning case in earthquake-damaged emergency process on slope engineering, which exemplified the outcome could reflect more risk information than the method of standard DEA model, and reflected the rationality, feasibility, and impersonality, revealing its better ability on comprehensive safety and structure risk.

The risk early-warning of gas hazard in coal mine based on Rough Set-neural network

This article proposed the risk early-warning model of gas hazard based on Rough Set and neural network. The attribute quantity was reduced by Rough Set, the main characteristic attributes were withdrawn, the complexity of neural network system and the computing time was reduced, as well. Because of fault-tolerant ability, parallel processing ability, anti-jamming ability and processing non-linear problem ability of neural network system, the methods of Rough Set and neural network were combined. The examples research indicate： applying Rough Set and BP neural network to the gas hazard risk early-warning coal mines in coal mine, the BPNN structure is greatly simplified, the network computation quantity is reduced and the convergence rate is speed up.

A Note on Improving Inference of Relative Risk

Relative risk is a popular measure to compare risk of an outcome in the exposed group to the unexposed group. By applying the delta method and Central Limit Theorem, [1] derives two approximate confidence intervals for the relative risk, and [2] approximates the confidence interval for the relative risk via the likelihood ratio statistic. Both of these approximations require sample size to be large. In this paper, by adjusting the likelihood ratio statistic obtained by [2], a new method is proposed to obtain the confidence interval for the relative risk. Simulation results showed that the proposed method is extremely accurate even when the sample size is small.

Minimum MSE Weighted Estimator to Make Inferences for a Common Risk Ratio across Sparse Meta-Analysis Data

The paper aims to discuss three interesting issues of statistical inferences for a common risk ratio (RR) in sparse meta-analysis data. Firstly, the conventional log-risk ratio estimator encounters a number of problems when the number of events in the experimental or control group is zero in sparse data of a 2 × 2 table. The adjusted log-risk ratio estimator with the continuity correction points based upon the minimum Bayes risk with respect to the uniform prior density over (0, 1) and the Euclidean loss function is proposed. Secondly, the interest is to find the optimal weights of the pooled estimate that minimize the mean square error (MSE) of subject to the constraint on where , , . Finally, the performance of this minimum MSE weighted estimator adjusted with various values of points is investigated to compare with other popular estimators, such as the Mantel-Haenszel (MH) estimator and the weighted least squares (WLS) estimator (also equivalently known as the inverse-variance weighted estimator) in senses of point estimation and hypothesis testing via simulation studies. The results of estimation illustrate that regardless of the true values of RR, the MH estimator achieves the best performance with the smallest MSE when the study size is rather large and the sample sizes within each study are small. The MSE of WLS estimator and the proposed-weight estimator adjusted by , or , or are close together and they are the best when the sample sizes are moderate to large (and) while the study size is rather small.

基于贝叶斯攻击图的油气生产物联网系统风险评估

针对油气生产物联网系统动态风险评估问题,提出一种基于贝叶斯攻击图的油气生产物联网系统风险评估模型。首先通过对系统进行风险分析,得到入侵证据及系统漏洞,结合入侵证据和漏洞利用成功概率,采用EM算法对训练数据进行数据补全并动态更新贝叶斯攻击图的条件概率参数表,通过条件概率表可计算得出先验概率,结合入侵证据计算得到节点的后验概率,进而得到系统的风险值,考虑资源利用的相关性对风险值进行最终修正。仿真结果分析证明了该模型的有效性和准确性。

基于指标修正的AHP-FCEM法长输油气管道风险评价

针对国内在用长输油气管道使用管理过程中存在的高风险、事故多发、风险不可控的现状,在多方位调研的基础上,提出一种综合了层次分析法(AHP)、区间估计分析理论和模糊综合评价法(FCEM)的评价方法。利用层次分析法的优势建立初步评价体系,接着采用区间估计分析理论对“弱权重指标”进行筛选,优化形成包含5个Ⅰ级指标和25个Ⅱ级指标的最终评价体系,最后应用模糊评价法通过两级运算确定评价目标的模糊隶属度,进而得到管道的风险等级。实例验证表明,该评价方法的结果与实际情况相吻合,可为长输油气管道的科学化管理提供技术支撑。

Analysis of Early-Warning Threshold for Metro Construction Collapse Risk Based on D-S Evidence Theory and Rough Set

The existing early-warning system in metro construction are generally based on traditional single-sensor data and simple analytic model, which makes it difficult to deal with the complex and comprehensive environment in metro construction. In this paper, the framework of early-warning threshold for metro construction collapse risk based on D-S evidence theory and rough set is built. By combining the primary data fusion collected based on rough set with the secondary data fusion which is based on D-S evidence theory, the integration of multiple information in metro construction is realized and the risk assessment methods are optimized. A case trial based on Hangzhou metro construction collapse accident is also carried out to exemplify the framework. The empirical analysis guarantees the completeness and independence of the prediction information, and realizes the dynamic prediction of the variation trend of metro construction collapse risk.

多发性骨髓瘤合并肾功能不全患者的临床特征及危险因素分析

目的:对伴有肾功能不全的多发性骨髓瘤(MM)患者的临床特征及其影响因素进行研究。方法:选取2020年1月—2023年3月在我院血液肿瘤科住院的146例诊断MM患者为研究对象,按肾功能水平分为肾功能正常组(98例)和肾功能不全组(48例)。采集并记录所有患者的相关临床资料和实验室检查指标,对其临床特点与肾功能不全的相关影响因素进行回顾性分析。结果:在146名MM患者中肾功能不全发病率为32.9%;与肾功能正常组相比,肾功能不全组血红蛋白较低,年龄、尿酸、校正钙、LDH、白细胞计数、血清β_(2)-微球蛋白和骨髓浆细胞比例较高,差异有统计学意义(P<0.05);经Logistic回归因素分析显示校正钙和血清β_(2)-微球蛋白是MM患者发生肾功能不全的影响因素。ROC曲线分析表明校正钙曲线下面积为0.689 1,灵敏度56.3%,特异度82.7%,最佳截取值为2.465mmol/L;β_(2)-微球蛋白曲线下面积为0.897 9,灵敏度81.3%,特异度83.7%,最佳截取值为6.315mg/L。结论:MM患者肾功能不全的患病率较高,且校正钙和β_(2)-微球蛋白为肾功能不全的关键因素,并对MM患者肾功能损伤有一定的辅助诊断价值,应关注上述指标并及时采取针对性防治措施,以改善患者生活质量和预后。

Research on the Method of Shipping Risk Early-Warning Based on Matter-Element Theory

The purpose of shipping risk early-warning is that some effective measures are taken to reduce risk probability before the risk brings heavy loss.The shipping risk has the dynamic characteristic,so the key of early-warning is to choice risk early-warning index correctly and evaluate risk grade quantitatively.According to the element extension theory,the rhombus inference model is applied to establish the index system.And the problem of risk grade evaluation can be solved by the assessment model of multi-index performance parameter,which is developed by the extension engineering method.Finally,the main shipping risks and their grades are identified by the example analysis based on the statistical data,which shows the effective and feasible of the shipping risk early-warning method.

电网频率校正控制方法在高比例新能源电网的适应性

新能源出力由自然禀赋决定,在电力平衡约束下的高比例新能源电网运行方式调整范围逐渐增加,传统固定策略的频率校正控制方法失配风险不断提高。建立典型系统,给出了研究频率校正控制的电网运行场景域描述方法,计算了频率校正控制系统任一轮次适应的电网运行场景域。提出将控制量可整定的范围作为评价任一轮次适应性的指标,使用多个轮次的最小可整定范围评价频率校正控制系统的适应性。利用实际电网参数建立分析模型,计算频率校正控制系统适应的极限新能源接入比例。传统频率校正控制方法难以适应新能源比例高的场景,亟需新型控制方法。

区块链技术赋能思政教育的优势、风险及纠偏措施

区块链技术在思政教育场景下,对推动评价模式创新发展、调动思政教育主体活力、构建新型思政信任环境、激发教育主体协同效应具有重要意义。然而,区块链技术本身的多中心结构、脚本可编程性、标准化规则等,也可能存在数据存储不安全、削弱主流价值导向、淡化思政人文精神等风险。要对区块链技术赋能思政教育的隐藏风险预先识别,并结合大语言模型等技术,给出纠偏措施,以促进区块链技术在思政教育场景中更好地落地。

基于风险势场的网联自主车辆换道行为建模

为提高智能网联环境下网联自主车辆的换道安全,针对网联自主车辆环境感知及实时通讯的特点,以势场理论为基础,分析车辆不同方向所面临风险变的差异性,对动态车间距进行修正,构建车辆风险势场模型,将网联自主车辆驾驶过程中所面临的风险进行量化,以此为基础建立网联自主车辆安全换道距离模型,反映不同运动状态的换道车辆所需要的安全换道距离的变化趋势。对模型进行数值模拟分析,结果表明:当前车道和目标车道上车辆的运动状态直接影响换道时所需要的安全距离的大小。可见车辆进行换道操作时需调整自身的运动状态来改变风险势场的分布情况,避免与其他车辆的风险势场发生冲突,影响行车安全性。

步态矫正训练对老年糖尿病危险足患者足底压力的影响

目的探讨步态矫正训练对老年糖尿病危险足患者足底压力的影响。方法选取2022年9-10月在上海市2家社区卫生服务中心就诊的老年糖尿病危险足患者88例,采用抽签法将1家社区卫生服务中心的43例患者作为对照组,另1家社区卫生服务中心的45例患者作为观察组,干预过程中,观察组失访2例,对照组失访1例,最终纳入分析的患者共85例,其中对照组42例,观察组43例。对照组接受社区糖尿病健康教育及社区常规运动,观察组在对照组的基础上进行步态矫正训练,均进行为期3个月的干预。比较2组患者干预前后左、右足足底压力相关指标(峰值压力、冲量和最大力)。结果干预3个月后,观察组左、右足的峰值压力、冲量及最大力均低于对照组,差异有统计学意义(P<0.05)。结论步态矫正训练可降低老年糖尿病危险足患者左、右足的峰值压力、冲量及最大力等足底压力相关指标,改善下肢功能,预防及减少足溃疡的发生风险。

^(131)I核素治疗操作方式修正因子对辐射安全风险的影响

为更好地保障碘-131(^(131)I)核素治疗工作人员的职业健康与安全,提高^(131)I核素治疗的使用率,选择深圳市10家医院的^(131)I核素治疗工作场所为研究对象开展研究。采用碘盒滤膜采样法,通过低本底高纯锗γ能谱仪和无源效率刻度软件,测量核医学工作场所关键区域中^(131)I的活度浓度。估算职业人员待积有效剂量,评估职业人员辐射安全风险,进而探讨^(131)I核素治疗操作方式修正因子变更对职业人员辐射安全风险的影响。结果表明:采用厂家配送和自动分装方式的核医学工作场所中,^(131)I(液态)核素治疗操作方式修正因子设定为10时,带来的辐射安全风险仍远低于标准限值;建议将^(131)I(液态)核素治疗操作方式修正因子按分装方式进行区分,手动分装设定为1,厂家配送和自动分装方式设定为10。

基于熵值修正G2赋权的航空公司疲劳风险管理系统有效性评价

为帮助航空公司持续优化疲劳风险管理系统(fatigue risk management system,FRMS),通过系统分析FRMS有效运行的关键要素,构建了疲劳风险管理系统有效性评价模型,以提高航空公司疲劳风险管理水平。在综合管理、政策文件、风险管理、安全保证、安全促进5个维度的基础上,构建FRMS有效性评价指标体系,采用熵值修正G2法确定各指标的权重,并结合模糊综合评价法,构建了航空公司疲劳风险管理系统有效性评价模型。以S航空公司为例,运用模型对其进行有效性评价,该航空公司的FRMS有效性评价结果为良好,符合实际情况。结果表明,该评价模型具有较好的可行性和适用性,可为航空公司疲劳风险管理系统优化提供重要参考。

先天性耳廓畸形患儿矫正治疗后近期疗效调查及预后不良危险因素分析

目的调查先天性耳廓畸形患儿矫正治疗后近期疗效,并对其预后不良危险因素进行Logistic回归分析。方法选取2021年1月到2022年12月在深圳市妇幼保健院耳鼻咽喉科接受EARWELL耳廓矫形器矫正治疗的先天性耳廓畸形患儿226例,采用自编的一般资料问卷,对研究对象基本情况及近期疗效进行问卷调查,并依据治疗3周后的结果将其分为预后不良组(31例)与预后良好组(195例),采用多因素Logistic回归分析矫正治疗预后不良的危险因素。结果226例先天性耳廓畸形患儿矫正治疗后,近期治疗有效率为85.84%(194/226)。治疗2个月后,预后不良发生率为13.72%(31/226)。预后良好组与预后不良组日龄、畸形类别、耳廓畸形Max分型、是否为母乳喂养状况比较,差异有统计学意义(P<0.05)。Logistic多因素回归分析结果显示:日龄>42d、杯状耳或招风耳、耳廓畸形MaxⅡ型、非母乳喂养是先天性耳廓畸形患儿矫正治疗后近期出现预后不良的独立危险因素(P<0.05)。结论先天性耳廓畸形患儿矫正治疗后近期疗效良好,且存在上述危险因素的先天性耳廓畸形患儿矫正治疗后近期出现预后不良的风险较大。

有限空间作业安全作业票审批规范管理的关键性分析与正确性保障策略研究

本文深入探讨了有限空间作业安全作业票审批的规范管理及其正确性保障策略。文章聚焦于有限空间作业的特殊性与风险,强调了安全作业票审批在作业安全管理中的核心作用。论文深入剖析了安全作业票审批的构成要素,识别了其中的关键性因素,如作业信息的准确性、审批流程的合理性以及风险防控措施的有效性等。文章进一步提出,规范管理是确保安全作业票正确性的重要保障。通过对现有管理实践的分析,揭示了当前存在的问题,如制度执行不严、信息填写不规范、审批流程不透明等。针对这些问题,论文构建了一套完整的正确性保障策略,包括完善管理制度、优化审批流程、强化培训教育、应用信息化技术等,旨在提升安全作业票审批的管理水平,降低作业风险。此外,文中还探讨了如何通过持续改进和监督机制,确保策略的有效实施和安全作业票审批的正确执行。通过实证分析和案例研究,论证了所提策略在实际中的可行性与优越性。本文的研究成果不仅为水泥企业提供了有限空间作业票审批的管理指导,也为其他行业和领域的安全作业票审批规范管理提供了参考,对于提升整体作业安全水平具有积极意义。

煤矿井下地磁定位的日变研究

近年来定位技术发展十分迅速,其中井下定位技术成为研究热点。在井下突发人员逃生、救援定位与导航等应急情况时,地磁定位可在无网络、无电时利用单兵PDA中内置的地磁基准图进行精准定位。首先分析了井下地磁定位的机理,并构建了井下地磁定位框架;再针对井下地磁的扰动现象进行日变测量,并分析了其变化规律。多项实验结果表明,在无干扰条件下,井下地磁变化较小且呈周期性变化。

眼内异物合并感染性眼内炎的急诊玻璃体切割手术疗效观察

目的分析眼内异物伴眼内炎患者采取玻璃体切割术的疗效。方法纳入2021年4月至2024年4月银川进川眼科医院急诊收治的80例眼内异物合并感染性眼内炎患者,所有患者均进行了急诊玻璃体切割手术治疗。分析所有患者的一般临床资料、眼内异物情况、手术效果、术后视力的影响因素。结果80例患者中,71例为男性(88.75%),9例为女性(11.25%);73例患者为18~65岁之间的中青年(占91.25%);61例患者来自于乡镇(占76.25%)。47例患者眼内异物为金属类(占58.75%),50例患者眼部异物进入区域为I区(占62.50%),43例患者眼部异物较小,直径小于3 mm(占53.75%),65例患者眼部异物嵌顿在黄斑区外(占81.25%)。所有患者眼内异物经Ⅰ期手术均成功取出;术前仅有14例(17.50%)患者术前最佳矫正视力(Best Corrected Visual Acuity,BCVA)≥0.1,而术后一周有33例(41.25%)患者的BCVA≥0.1,手术明显改善了患者的视力情况(P=0.001)。术前BCVA<1、伴视网膜脱离、异物直径≥3 mm是影响患者术后视力恢复的独立危险因素。结论玻璃体切割术可有效改善BCVA,临床疗效显著;且影响患者术后视力的因素主要与术前BCVA、视网膜脱离以及异物直径有关。

天然气长输管道地区等级升级管理与风险评价

为了有效管理和控制地区等级升级后所引起的输气管道风险变化,有必要依据管道完整性管理的基本原则,结合输气管道地区等级变化条件,制订相应的管理流程,建立风险评价模型,并提出风险管控原则。为此,首先结合地区等级划分标准识别高后果区,分类管理地区等级升级后的管段。然后,评价地区等级升级后管段的风险水平:①引入模糊语言与其量化值修正EGIG统计的失效概率,得到适用于特定管段的总失效概率;②按最严重事故后果选取蒸气云爆炸模型进行计算,依据泄漏50%致死率估算出死亡人数作为后果等级评价标准;③依据失效概率与失效后果,利用风险矩阵评定风险等级。最后引入风险可接受准则,分析管道泄漏的个人风险与社会风险,判定管道地区等级升级后的风险可接受性。案例分析结果表明:①地区等级升级后天然气长输管道风险也随之增大;②对于升级后风险增大的管段,需根据风险管控原则决定是否采取安全措施。