Assessment of Multiple Working Condition System Reliability with Agent-Based Simulation Method

The mission reliability assessment plays a great role in logistics planning and supporting resource optimization of complex system.But the current problem,which is difficult to solve,is how to model and analyze the characters of system reliability under the complex mission profile.In order to solve the problem,an agentbased simulation method was used to assess reliability for complex systems with various random working conditions.A multi-working condition simulation agent(MA)was designed and used to simulate the random transferring process of working conditions of system,and it cooperated with system simulation agents(SAs)and unit simulation agents(UAs)to realize system mission reliability(MR)simulation.Through simulation experiments,effect of multiple working conditions mission on the reliability of system was analyzed by comparing with the basic reliability condition.Feasibility and efficiency of the method were proved through simulation experiments of the case system.The research result provides a viable and useful method and a solution for MR analysis and assessment of complex systems in multi-working conditions,which can help to evaluate the reliability of operating system orienting to the practical mission and environment,and it is meaningful for the reliability analysis and the design of complex systems.

FNM method for estimating reliability of existing bridges

Combined with current specifications and stress characteristics of concrete filled steel tubular （CFST） arch bridges, the determination principle of safe-middle-failure threestage mode is given. Accordingly, damage probability and failure probability and the corresponding reliability indices are calculated; a direct relationship between reliability indices and three-stage working status is made. Based on the three-stage working mode, a combined FNM （finite element-neural network- Monte-Carlo simulation） method is put forward to estimate the reliability of existing bridges. According to time-dependent reliability theory, subsequent service time is divided into several stages; minimum samples required by the Monte-Carlo method are generated by random sampling; training samples are calculated by the finite element method, and the training samples are extended by the neural network; failure probability and damage probability are calculated by the Monte-Carlo method. Thus, time dependent reliability indices are obtained, and the working status is judged. A case study is investigated to estimate the reliability of an actual bridge by the FNM method. The bridge is a CFST arch bridge with an 83.6 m span and it has been in operation for 10 years. According to analysis results, in the tenth year, the example bridge is still in safe status. This conclusion is consistent with the facts, which proves the feasibility of the FNM method for estimating the reliability of existing bridges.

Reliability analysis of torpedo loading based on fractional-order optimization model

A fractional-order cumulative optimization GM(1,2)model based on grey theory is proposed to study the relationship between torpedo loading and working reliabilities.In this model,the average relative error function related to order and background value is established.Taking the average relative error function as the objective function,the optimal value of the two parameters is obtained through the optimization method,and the minimum value of the average relative error is determined.The calculation example shows that this method can greatly improve the accuracy of the model and more accurately reflect the relationship between torpedo loading and working reliabilities compared with the traditional GM(1,2)model.

Reliability Analysis Method of a Control System for Subsea All-Electric Christmas Tree

The subsea all-electric Christmas tree(XT) is a key equipment in subsea production systems.Once it fails,the marine environment will be seriously polluted.Therefore,strict reliability analysis and measures to improve reliability must be performed before a subsea all-electric XT is launched;such measures are crucial to subsea safe production.A fault-tolerant control system was developed in this paper to improve the reliability of XT.A dual-factor degradation model for electrical control system components was proposed to improve the evaluation accuracy,and the reliability of the control system was analyzed based on the Markov model.The influences of the common cause failure and the failure rate in key components on the reliability and availability of the control system were studied.The impacts of mean time to repair and incomplete repair strategy on the availability of the control system were also investigated.Research results show the key factors that affect system reliability,and a specific method to improve the reliability and availability of the control system was given.This reliability analysis method for the control system could be applied to general all-electric subsea control systems to guide their safe production.

Evaluation of the Fatigue Characteristics of Laser-processed Hot Work Tool Steel Based on Reliability

It is reported that laser-processing is effective to repair the heat checks, which are fine shallow cracks on a surfaceof die-casting dies. In this study, the rotating bending fatigue tests have been carried out to evaluate the fatiguecharacteristics of laser-processed hot working tool steel. Because test results are scattered, S-N curves are decidedbased on the evaluation of fatigue strength distribution. As a result, the fatigue strength of the laser-processedspecimens decreases remarkably in comparison with that of base metal. However, it can be recovered to almostinitial value by heat treatment at secondary hardening temperature. This procedure is also effective to decrease thescatter of fatigue strength. The laser-processing can be carried out at low cost and this method is effective for theextension of the work life of dies.

Analysis of Effective Working Hours of Automatic Assembly Equipment for Aircraft Assembly Stations

To improve the accuracy of capacity analysis and prediction for the aircraft assembly stations,an approach for calculating the effective working hour(EWH)of automatic assembly equipment is introduced by using the dynamic mixed Weibull distribution(DMWD)model.Firstly,according to the features of aircraft assembling,a DMWD model considering the dynamic reliability of multiple subsystems and their synthetic effects on the whole equipment is established.A typical automatic drilling&riveting machine is selected as the research object,and the dynamic weights of reliability of three subsystems are modeled and solved.Subsequently the unknown parameters of the DMWD model are estimated based on maximum likelihood estimation(MLE)and Newton-Raphson method.Finally,the EWH of an automatic station is defined and modeled by using the solved dynamic reliability function.Based on the experimental study on a real automatic drilling&riveting machine from a wing panel assembly station,it is shown that the proposed DMWD and EWH models could effectively calculate the equipment reliability with full consideration of its multiple subsystems.The DMWD model is more suitable for improving the solution precision of EWH than the traditional three-parameter Weibull distribution.

Improving the Reliability of Computer Communication Networks

For networks that are directed or can be represented by a directed network,reversing one or more of the uni-directional links may provide the ability to reconnect a network that has been disconnected by link failure, In this paper,a new approach to reconfigure such networks is proposed.We develop a linear time algorithm which,when reachability has been destroyed by the removal of a single link,optimally restores teachability through the reversal of selected links.Multi-link failure reconnectability is discussed and an algorithm with polynomial complexity is given which provides a nearly optimum solution to reconnect the network.We show that the reliability of a network that allows reversals is at least twice more than that in which reversals are not permitted.Unfortunately,the reconnection of some networks cannot be established.Therefore,we discuss the maximization of reachability of such networks so that each node can reach maximum number of the other nodes.

基于允许可靠度的薄壁圆筒静强度安全系数

为建立钢制单层承压薄壁圆筒静强度的可靠性设计技术,当圆筒静强度与载荷分别符合正态分布且静强度分布参数为区间值时,应用概率论知识,构建了圆筒静强度在不同工况的可靠度系数、安全系数和工况系数三者之间的关系。研究表明:1)在一般气压试验或气液组合试验时,圆筒屈服强度的允许可靠度系数应不小于1.549且不超过2.115,爆破强度的允许可靠度系数应不小于4.081且不超过5.414。2)在一般液压试验时,圆筒屈服强度的允许可靠度系数应不小于0.605且不超过1.005,爆破强度的允许可靠度系数应不小于3.304且不超过4.430。3)在正常操作时,圆筒屈服强度的允许可靠度系数应不小于1.961且不超过2.484,爆破强度的允许可靠度系数应不小于4.280且不超过5.456。4)在允许可靠度系数满足上述取值范围,且工况系数符合中国标准时,圆筒屈服安全系数可取1.40,爆破安全系数可取2.00。

基于GMM的流体旋转设备运行可靠性在线评价方法

针对流体旋转设备运行工况多变且难以区分,导致运行可靠性评价准确率低的问题,提出了一种基于高斯混合模型(GMM)的流体旋转设备运行可靠性在线性评价方法。首先,根据设备历史运行数据,基于快速搜索和发现密度峰值的聚类算法(DPC),进行工况划分,构建不同工况条件下的基于GMM的运行可靠性基准模型;其次,使用XGBoost算法对设备实时运行状态进行工况识别,约减冗余指标,构建设备运行可靠性的评价指标体系;然后,计算度量评价指标与对应工况下基准模型指标的偏离程度,以马氏距离作为度量标准,进一步计算得到设备运行可靠性评价指数;最后,以矿用离心机设备为例,进行了多工况下的运行可靠性实例分析和模型验证。研究结果表明,该方法能够在线实时反应设备当前的运行可靠性水平,当离心机设备运行可靠性低于0.857时,认为设备进入劣化状态,且评价准确率达到98%以上。

一种双匙联动保管箱锁的锁芯及锁匙设计分析

设计了一种双匙联动的银行保管箱锁的锁芯部件以及与之对应的锁匙,锁芯部件由10片叠放在一起的锁芯片、1个锁芯拔套、1个小圆垫和1个顶簧组成,通过大圆垫和卡簧将其装配在锁壳中。这种锁芯部件结构紧凑简单、零件数量少、加工工艺性好、装配调试方便、锁具的不相重性大、安全可靠,并且与锁芯对应的锁匙强度高、大气美观。

液压支架结构的可靠性设计研究

针对国内液压支架在结构件可靠性方面与国外产品的差距,依托2套出口支架产品,阐述了应用于中厚煤层高工作阻力液压支架的顶梁底座柱窝、掩护梁、连杆的抗弯、抗扭性结构设计,对这些结构的技术特征、创新性、应用范围进行了分析研究。2套出口支架顺利通过了按美国CONSOL标准进行的60 000次型式试验,试验结果表明,所述结构切实提高了支架的抗弯、抗扭性能,提高了液压支架的可靠性。

三相组合式强迫油循环风冷变压器检修平台研制

对于地处偏僻、交通不便的大容量水力发电机组,往往选用体积小、便于运输的三相组合式强迫油循环风冷变压器。此类变压器油箱顶部空间狭小、遍布管路,挤压了检修操作空间;部分套管与消防喷淋系统的安装位置、油箱底部事故油池及鹅卵石的铺设等加剧了检修人员高处坠落的安全风险,同时也使普通脚手架无法满足现场检修要求。为此,设计了一种方便检修、安全可靠、通用性强、可快速拆装、成本低的三相组合式强迫油循环风冷变压器检修平台,社会与经济效益显著。

支路开关自放电对大型多路并联FLTD脉冲源可靠性的影响

快脉冲直线型变压器驱动源(fast linear transformer driver,FLTD)是建设下一代大型Z箍缩装置最有前景的技术路线之一。大型FLTD脉冲源中数以万计气体开关的可靠运行是提高Z箍缩装置可靠性的重要因素。该文基于15 MAZ箍缩科学实验装置的FLTD脉冲源设计,采用Monte-Carlo方法建立考虑支路开关自放电及其载荷共享效应的FLTD脉冲源可靠性计算模型,分析开关故障模式及其触发策略对脉冲源可靠性的影响。结果表明,主支路开关自放电产生的故障电压会引起开关级联自放电,降低装置可靠性。若主支路开关工作系数设定在0.5~0.7范围内,FLTD脉冲源故障率可低于1×10^(-4)。此外,触发器及触发支路开关的高可靠性对于提升脉冲源可靠性至关重要,增加触发器脉冲数量、降低触发器自放电故障率能够有效提升脉冲源可靠性,当触发器脉冲数量提升至4倍后,FLTD脉冲源故障率有望降低至1×10^(-5)以下。研究结果为大型FLTD脉冲源的开关工作系数及触发策略的选取提供参考,具有重要的工程应用价值。

工作-生活平衡量表在护士工作-生活平衡状态中的应用评价

目的探讨工作-生活平衡量表用于测评护士工作-生活平衡状态的信度和效度,为调查护士工作-生活平衡状态提供科学、严谨的测评工具。方法2023年2月1日至3月1日使用工作-生活平衡量表对广西医科大学第一附属医院、广西医科大学第二附属医院、广西医科大学附属武鸣医院3所三甲医院具有临床工作经验1年及以上的526名护士进行测定,并对测评结果进行信效度检验。结果总量表Cronbach′s α系数为0.940,分半信度为0.881;3个因子内部Cronbach′s α系数为0.819~0.930,折半信度为0.796~0.899,量表信度良好。该量表包含3个因子,累积解释方差变异为68.857%。每个条目的因子载荷值为0.468~0.862,而条目的具体归属则与以往的研究结论有所不同。3个分量表间的相关系数为0.515~0.663,总量表的相关系数为0.731~0.949,说明量表结构、内容效度良好。验证性因素分析量表的理论模型剔除2个条目后标准化残差均方根为0.070,比较拟合指数为0.904。结论工作-生活平衡量表测评护士工作-生活平衡状态具有较好的信度和结构效度,模型拟合度稍差,建议扩大样本量进一步验证。

中青年急性心肌梗死患者重返工作障碍量表编制及信度效度检验

目的:编制中青年急性心肌梗死患者重返工作障碍量表并检验其信度、效度,为评估中青年急性心肌梗死患者重返工作障碍程度提供可靠工具。方法:基于Feuerstein模型,通过文献研究、访谈和德尔菲专家函询法,形成初始量表。采用便利抽样法,选取2022年8月—11月浙江省某综合性医院414例中青年急性心肌梗死患者进行正式调查,筛选条目并检验量表的信度、效度。结果:中青年急性心肌梗死患者重返工作障碍量表包含4个维度,20个条目。探索性因子分析最终提取4个公因子,累计方差贡献率为64.437%。量表各条目内容效度指数为0.80~1.00,平均内容效度指数为0.94。量表总的Cronbach’sα系数、重测信度分别为0.915、0.997。结论:中青年急性心肌梗死患者重返工作障碍量表具有良好的信度、效度,可作为中青年急性心肌梗死患者重返工作障碍程度的评估工具。

护理人员安全注射知信行调查问卷的编制及信效度检验

目的编制护理人员安全注射知信行调查问卷,并对其进行信效度检验。方法基于知信行理论模式,通过文献分析构建问卷初始版,经德尔菲专家函询法对问卷进行修订,形成问卷测试版。选取北华大学附属医院的589名护理人员进行调查,应用探索性因子分析、验证性因子分析、内容效度测评问卷的效度,采用内部一致性系数、折半信度对问卷的信度进行分析。结果形成的护理人员安全注射知信行调查问卷包含3个维度和60个条目。问卷总体内容效度指数为0.930;各条目内容效度指数为0.880~1.000,探索性因子分析共提取3个公因子,累计方差贡献率为64.55%。问卷整体的Cronbach′s α系数为0.973,折半信度系数为0.879,重测信度为0.977。结论编制的护理人员安全注射知信行调查问卷具有良好的信度和效度,可作为我国临床护理人员安全注射知识、态度和行为水平的调查工具。

输电线路近(带)电作业时容易发生触电的30种情况及应对策略

总结了输电线路施工、停电检修、近电作业、带电作业中容易发生登杆触电、短路放电的常见情况,并对其提出相应的应对策略。

肿瘤科安全用药管理方法及价值探讨

目的探讨肿瘤科安全用药管理方法的有效性和价值。方法选取2023年1—12月麻城市人民医院肿瘤科58名医务人员为研究对象。2023年1—6月为对照组,实施传统的用药管理方式。2023年7—12月为研究组,实施改进的安全用药管理措施。分别从两组抽取361份处方进行研究。比较两组医务人员工作质量及处方审核合格率。结果研究组药物选择合理性、用药执行准确性评分高于对照组,差异有统计学意义(P均<0.05)。研究组处方审核合格率为98.6%(356/361),高于对照组的91.7%(331/361),差异有统计学意义(χ^(2)=18.767,P<0.05)。结论改进的安全用药管理措施能够有效提高医务人员工作质量,提高处方审核合格率。

基于超声波传感器的无人天车避障技术研究

针对无人天车运行中因无法准确识别障碍物而引发事故发生的情况,提出了采用超声波传感器结合PLC控制实现对障碍物自动监测躲避的方法。通过传感器水平和垂直的安装方式,实现三维立体空间内全方位无死角的实时监测。传感器通过模拟量信号接口将障碍物信息发送至PLC系统,PLC系统依据实时位置信息控制天车提前作出准确反应以躲避障碍物,确保无人天车的安全可靠稳定运行。

高海拔地区配网带电作业安全距离探讨

随着用户对供电可靠性要求的提高,市政迁改、用户接火等工作采取“能转必转,能带不停”的方式,但是在海拔4500 m以上的地区开展配电带电作业缺乏相关技术标准,开展带电作业次数相对较少,因此结合低海拔地区配网带电作业成熟的研究成果以及常用海拔校正方法,对3000~5000 m范围内配网带电作业最小安全距离做了分析。