电力工程中的地质灾害危险性评估

我国幅员辽阔,地质环境条件多样且复杂,导致了地质灾害发育强烈,种类繁多、危害较大。地质灾害与工程建设活动密切相关,既相互作用,相互依存,又相互影响[1]。电力工程项目遍布全国,特别是输电线路大多为人烟稀少的山区分布,线路长,跨越的地质地貌区域复杂,存在的地质灾害多种多样,或多或少面临着各种地质灾害的严重威胁[2]。通过电力工程地质灾害危险性评估工作的现状及评估工作流程的介绍,进一步分析电力工程地质灾害的危险性评估工作中存在的问题并提出了相应的看法。     

台儿庄城区饮用水水源地水质放射性水平分析

为了解和掌握台儿庄城区饮用水水源地放射性水平和动态变化,本文以枣庄市生态环境局台儿庄分局提供的饮用水水源地水质放射性数据为基础,探讨了台儿庄城区饮用水水源地水质中α、β放射性质量浓度的动态变化。结果显示:水源地总α、β放射性质量浓度均低于标准限值,总α放射性质量浓度小于总β放射性质量浓度,总α、β放射性水平在水源地和季节变化中差异均不显著(P>0.05)。水源地水质总放射性水平符合我国规定的饮用水指导值。     

Forest harvesting in rural properties: Risks and worsening to the worker’s health under the ergonomics approach

Through an ergonomic approach, this study aimed to evaluate whether workers involved in forest harvesting activities in rural properties are subject to the development of work-related diseases, as well as their consequences. A cross-sectional study with 267 forest workers in rural properties in the Brazilian Central region was used. The following evaluations were performed for each of the activities (felling, delimbing, tracing, manual extraction and manual loading): physical workload evaluation; biomechanical evaluation; risk of repetitive strain injuries/work-related musculoskeletal disorders; environmental noise and vibration factors, where relevant, and thermal overload through the Wetbulb Globe Temperature index. The results showed that in general the physical workload was very high, exceeding the cardiovascular load limits and adding to the need for work reorganization. All activities exposed workers to serious and imminent risks of developing injuries to the spine and lower limbs. Likewise, in general the risk of the appearance of RSI/WMSDs was very high for all activities evaluated. Such results are due to the combination of organizational work factors and factors of the work environment such as exposure to bad weather, uneven terrain, lifting and handling loads above tolerable limits, excessive noise and thermal overload. All of this allows to conclude that ergonomic risks and workers’ health hazards in forest harvesting in rural properties are latent and very worrying, and that these workers are exposed to a form of labor exploitation that invariably leads to physical and emotional exhaustion and therefore to their decreased labor capacity and useful working life.     

The impact of risk and protective factors on online teaching experience in high school Italian teachers during the COVID-19 pandemic

The lockdown due to COVID-19 in Italy resulted in the sudden closure of schools, with a shift from traditional teaching to the online one. Through an online questionnaire, this survey explores teachers' experience of online teaching, the level of risk factors (e.g., stress) and protective factors (e.g., locus of control) and their impact on satisfaction levels during the social distancing. One hundred seven high school teachers from Lombardy, an Italian region very affected by the COVID-19 outbreak, participated. Results show that depression and stress are the main predictors of satisfaction levels for online teaching. In addition, coping, locus of control and self-efficacy emerge as important protective factors. Finally, although there is great satisfaction with the online teaching experience, critical elements emerged. This study is relevant because it describes the critical elements of the online teaching experience, and identifies some protective factors and the main risk factors in teachers operating in an area strongly marked by social restrictions imposed by the pandemic. High school teachers emerge as a sub-group of the general population with specific psychological reactions. Considering the results, it is possible to suggest providing high-quality educational support and crisis-psychological oriented services to teachers, and help to maintain the psychological well-being.     

一种基于网络安全风险评估的入侵检测方法

针对传统的入侵检测系统存在报警数量大、误报率高等缺陷,提出了一种基于网络安全风险评估的入侵检测方法,该方法基于入侵检测结果,引入抗体浓度随入侵强度动态变化这一人工免疫理论的最新研究成果进行网络安全风险的计算,然后根据当前网络面临的实时安全风险动态设置报警策略。实验结果表明,该方法能够实时、定量地计算主机和网络所面临的风险,并极大地降低报警数量和误报率。     

一种测量工业环境感应传导干扰的方法

针对采用干扰测量仪或频谱分析仪只能测量工业环境中干扰源的辐射干扰强度的问题,提出了一种测量工业环境感应传导干扰的方法。该方法采用HBYV非双绞2芯线作为干扰接收体,采用数字示波器记录干扰波形的最大幅值和单个脉冲的最大强度,通过与标准干扰发生器感应到HBYV非双绞2芯线上的干扰信号大小进行比较,确定干扰强度。以瞬变脉冲群干扰强度和浪涌干扰强度的测量为例,详细介绍了该方法的具体实现。     

空中交通预警与防撞系统(TCAS)风险及对策研究

空中交通预警与防撞系统TCAS对飞行安全非常重要,它能够通过对附近的飞机进行冲突检测,预测未来可能发生的危险,提示飞行员避免危险,帮助机组维持与其他飞机之间的空中交通安全间隔;但TCAS本身依然存在风险;在此对TCAS进行了半物理仿真测试,包括数字样机开发测试、物理样机开发测试、虚拟试飞以及数据统计分析等,对其各项功能进行测试与验证;在参阅众多相关文献的基础上,结合所做的研究工作,讨论了TCAS的主要风险,并针对这些风险,提出TCAS在设计、测试、操作方面需要改进的地方,从各方面完善TCAS,降低其风险,进一步保障飞行安全。     

开源自动化控制软件Sedona在物联网中的应用

通过讨论物联网的现状、关键技术及发展方向,主要介绍了一种开源自动化控制软件Sedona在物联网的应用技术,包括在物联网架构中如何进行软件开发和应用程序设计,并介绍了该架构的技术特点。Sedona语言是一种通用的面向组件化的编程语言。Sedona虚拟机是一个小型解析器,具有良好的移植性,内嵌多种通信协议,可以运行在任何基于IP通信的网络上。最终实现各设备之间集中控制、分散管理的目标。     

An enhanced,acoustic emission-based,single-fiber-composite test

In the single-fiber-composite (SFC) test, a fiber imbedded in a matrix is loaded in tension, resulting in a fragmentation of the fiber. In the conventional version of this test, the final fiber fragmentation length distribution is used with a micro-mechanical model to determine the average fiber/matrix interfacial shear stress. In the enhanced version of this test, one also determines the applied stress at each fiber fracture, and from this, one can evaluate the strength of the fiber at short gage lengths. In our measurement system, we utilize an acoustic emission (AE) technique to detect the fiber fractures and to locate the fiber breaks and so determine both the fiber failure stresses as well as the fiber fragmentation lengths while the test is in progress. Critical to the success of this test is a broadband AE system that utilizes point-like AE sensors, procedures for evaluatingin situ, the wavespeed of the first wave arrival and signal processing techniques for determining the arrival time of this signal as precisely as possible for a broad range of wave shapes. Here we describe the application of such an enhanced SFC test procedure to investigate the failure of a Nicalon fiber in an epoxy matrix.     

Human error identification in human reliability assessment. Part 2: Detailed comparison of techniques

This is the second part of a two-part review of human error identification (HEI) approaches in human reliability assessment (HRA). Part 1 reviewed the probabilistic risk assessment (PRA) context in which HRA occurs, and then detailed 12 HEI techniques which have evolved in the field of HRA. Part 2 attempts to compare the way these techniques perform against a range of criteria relevant to HEI theoretical and empirical validity, and practical usefulness in applied HRA. It is hoped that these comparisons will help assessors in the selection of techniques for practical applications. The comparisons also point to research and development needs in the area of applied HEI.