基于混合粒子群算法的物流集气管网布局优化

气田集输系统优化设计是解决气田内部的集输管线、集气站、处理站等的合理分配问题,属于NP难点问题,合理规划气井的归属和选择集输管线可有效降低气田集气成本.以基准日均出气量和基准管道集输半径为基准建立日均出气量和管道集输半径的函数关系式,并以气井集气量、集气管道半径、集输距离、管线投资费用系数等为变量建立基于成本的井组划分...     

Reliability Analysis of Retracting Actuator with Multi-State Based on Goal Oriented Methodology

In order to conduct effective reliability analysis of retracting actuator with multi-state(success state,safety failure state and action failure state), we redefine type-3 operator in goal oriented(GO) method to describe three states of main charge of retracting actuator and improve type-15 operator in GO method to describe the logic relations of multi-state output. The quantitative and qualitative reliability analyses of retracting actuator are made based on GO method in this paper. The system state probability of retracting actuator is obtained through quantitative analysis, and its weakness is found through qualitative analysis. The analysis results show that GO method is effective to improve the reliability of retracting actuator, and this method is also feasible for reliability analysis of other complicated initiating explosive systems.     

Reliability Analysis of Excavator Rectifier Feedback System with Multi-State Components Based on Belief Universal Generating Function Method

In view of the complexity and uncertainty of system, both the state performances and state probabilities of multi-state components can be expressed by interval numbers. The belief function theory is used to characterize the uncertainty caused by various factors. A modified Markov model is proposed to obtain the state probabilities of components at any given moment and subsequently the mass function is used to represent the precise belief degree of state probabilities. Based on the primary studies of universal generating function(UGF)method, a belief UGF(BUGF) method is utilized to analyze the reliability and the uncertainty of excavator rectifier feedback system. This paper provides an available method to evaluate the reliability of multi-state systems(MSSs) with interval state performances and state probabilities, and also avoid the interval expansion problem.     

3S技术在数字化管道系统中的应用

以提升油气储运生产经营管理信息化为目的,运用3S技术分别对遥感技术、全球定位系统和地理信息系统的概念及其在油气储运企业的具体应用进行阐述和分析,最后,对3S技术在油气储运企业中的应用前景进行展望。3S技术为数字化管道提供管理规范,实现管道全生命周期内各类资源的有效利用,提高油气管道生产信息化管理水平及企业的生产效率,为企业效益的进一步提升奠定基础。     

基于支持向量机的发动机气路故障预诊断

为实现航空发动机气路故障在线预诊断,分析了地空数据链系统中发动机气路参数报文的协议格式,建立了基于支持向量机算法的发动机气路参数在线预测模型。以便携式地空数据链收发系统为硬件基础,构建发动机报文并行处理系统,获取建模所需的训练样本。利用最终误差预报准则确定样本数据嵌入维数,实现时序样本数据的相空间重构。提出自适应网格搜索法优化支持向量机建模参数,获得气路参数在线预测模型,与航路飞机建立地空数据链通信,预测气路参数趋势。预测结果表明:参数低压转子转速、高压转子转速、尾气温度与燃油流量的相对预测误差分别为2.5%、2.1%、1.9%与2.3%,因此,支持向量机模型具有较高预测精度。     

基于Kriging算法的压气机健康参数主从式插值建模

针对航空燃气轮机压气机数字化建模过程中由于缺少压气机流量系数导致模型精度偏低的问题,基于Kriging插值算法构造了面向压气机流量系数估计的主从式建模方法,分析了高维空间下对应于不同压气机换算转速的流量系数分布特征;基于流量系数的特征提取方法探索了流量系数、换算转速、增压比之间的映射关系,并提出了关于这三类参数的多维样本向量构造方法;基于Kriging算法建立了适用于燃气轮机过渡工况下压气机流量系数主从式插值模型. 研究结果表明:与传统的Kriging插值方法及牛顿插值法相比,基于主从式模型的流量系数计算结果更接近实际值,计算精度提高了近10%;主模型可输出流量系数的估值向量,插值效率相比传统Kriging模型提高了近15%.      

基于工作应变模态的管道损伤识别试验研究

为了检测管道损伤、进行实时安全评估和长期寿命预测,防止管道事故发生,利用振动损伤检测方法,针对管道的一维性质,推导了求解管道损伤应变模态差分公式,建立定位损伤、确定损伤程度的直接指标数学模型.对3根管道进行不同损伤工况下的物理模型试验和损伤识别分析,结果表明:管道固有频率最大变化率仅为6.71%,固有频率作为全局性参数用于结构损伤诊断存在模态频率识别效果不明显且信息量较少的局限性;应变模态敏度比差值在损伤区域出现明显的突变,能直观准确地识别管道损伤.      

电缆隧道开挖引起邻近地下管线位移分析

随着市政设施的不断完善,城市地下工程也在逐渐的增加,城市电缆隧道的施工势必会对其周围的既有地下管线产生一定的影响。通过运用有限元软件ANSYS建立三维模型,针对管线与隧道走向垂直以及管线与隧道走向平行这两种管线与隧道的相对位置关系,综合考虑管线的埋置深度、本身的材质、管径的大小、管线和隧道的水平间距四个方面的影响因素,对电缆隧道的开挖过程进行数值模拟,以地下管线的位移作为指标对模拟结果进行分析,结果表明这些因素均会对地下管线的位移产生明显的影响,得出一些规律,为以后的工程施工提供一定参考依据。     

大功率PEMFC空气系统电流跟随分段PID控制方法研究

为优化大功率燃料电池系统空压机控制效果,基于离心式空压机系统模型,提出了大功率质子交换膜燃料电池(proton exchange membrane fuel cell, PEMFC)空气供给系统的电流跟随分段PID控制方法.该方法以离心式空压机响应特性为基础,以实际工作电流为跟随目标,在动态响应与稳态控制阶段采用不同的PID参数进行闭环控制,并进行了模拟仿真研究.最后,在实验室已有的150 kW燃料电池系统基础上的实验验证,模拟仿真与实验验证结果表明,仿真模型计算误差控制在5%以内,准确的反映了离心式空压机与空气供给系统的特性,所提出的大功率PEMFC空气供给系统的电流跟随分段PID控制方法不仅能够满足PEMFC电堆稳态控制要求,同时将动态响应时间缩短至3 s以内,控制效果良好.      

管线三维建模及可视化分析

管线是主要的城市基础设施之一，管线三维建模与可视化是构建“数字城市”的重要内容。采用断面与体面三角剖分拟合方法构建弯曲管线、三连通管线的三维模型，给出建模的方法和步骤，以OpenGL作为三维图形应用程序接口，实现管线三维建模及可视化。     

基于“三阶段法”的高速铁路短期运量预测

考虑到我国未来年度的OD分布预测中的路网构成变化、区域经济布局变动、区域经济增长速度差异等一些具有时变性和特殊性因素,采用在“四阶段法”运量预测基础上改进而成的“三阶段法”进行高速铁路短期客运量预测。首先采用组合预测模型进行趋势运量预测,然后采用多元LOGIT模型进行方式分担,最后采用弹性系数诱增模型进行诱增运量预测。以京沪高铁为例,采用“三阶段法”预测了2014年和2015年京沪高铁本线及跨线单向客流量。     

Optimum Consecutive Preventive Maintenance Scheduling Model Considering Reliability

As an effective means for improving system condition and reducing failures, a reasonable preventive maintenance scheduling guarantees the stability and safety of the system. This paper studies a consecutive maintenance scheduling problem for single-component systems with imperfect maintenance, and an optimum model with minimum reliability constraint for minimal cost rate is developed based on the renewal theory. The agebased and reliability-based maintenance strategies are modeled and compared according to a numerical example based on the degradation data of the actual system, which also verifies the optimality of the reliability-based strategy. At last, the influence of some key parameters is discussed by sensitive analysis.     

Asynchronous complex pipeline design based on ARM instruction set

This paper proposes an asynchronous complex pipeline based on ARM-V3 instruction set. Muller pipeline structure is used as prototype, and the factors which may affect pipeline performance are analyzed. To balance the difficulty of asynchronous design and performance analysis, both complete asynchronous and partial asynchronous structures aere designed and compared. Results of comparison with the well-Rnown industrial product ARM922T verify that about 30% and 40% performance improvement of the partial and complete asynchronous complex pipelines can be obtained respectively. The design methodologies can also be used in the design of other asynchronous pipelines.     

基于多尺度排列熵和长短时记忆神经网络的航空发动机剩余寿命预测

针对航空发动机性能退化失效的变点和多状态参数的时间序列预测, 构建了基于多尺度排列熵算法和长短时记忆神经网络的剩余寿命预测模型; 使用多尺度排列熵算法对时间序列进行变点分析, 求解出性能退化过程中的突变点, 得到了有故障征兆的性能退化起始点; 构建了包含多变量的长短时记忆神经网络模型, 将多个状态参数代入到模型中得到对应的剩余寿命; 将变点后的航空发动机多状态参数和剩余寿命作为样本, 代入到长短时记忆神经网络模型中进行多步和多变量的时间序列预测; 通过综合航空发动机状态参数变点分析方法和时间序列预测模型, 得到最终的剩余寿命预测结果。研究结果表明: 多尺度排列熵算法能够及时监控各个状态参数的变化, 当发现状态参数异常时, 排列熵的值会发生跳变, 从而有助于及时发现故障征兆; 长短时记忆神经网络模型通过门控单元对长时间序列数据进行信息筛选, 充分保留了有效信息用于时间序列预测; 多变量长短时记忆神经网络能够对多状态参数进行同步分析, 并且将状态参数直接与剩余寿命相对应, 提高了模型效率; 通过多尺度排列熵算法和长短时记忆神经网络模型的结合, 能够考虑到航空发动机的多退化模式, 得到更符合实际退化过程的剩余寿命预测结果; 经过算例分析, 提出方法的剩余寿命预测的均方根误差为5.3, 与长短时记忆神经网络、反向传播神经网络和支持向量机相比, 误差分别降低了63%、72%和78%。      

Experimental Study of Surface Detection of Gas Pipeline Buried in Soil

IntroductionGas pipelines buried in soil are necessary intransport process of city gas. Whether it is safe ornot is related to the safety of tens of thousands do-mestic customers in life and the industrial cus-tomers in work.Because of the high-speed development of thegas business in Shanghai, the gas users are ex-panded from hundreds of thousands in several mil-lions, and the gas pipeline is also developed fromingot tube into steel pipe. The underground steel-pipelines will bring into all ki…     

公路旅游运输客运量预测

公路旅游客运量的预测是公路旅游运输客运发展和管理的基础 ,也是地区未来旅游发展趋势的预测 .笔者结合公路旅游客运的特点 ,提出了地区旅游客运总量的“弹性系数法”的常规预测模型 ;公路旅游客运量的“景点容量—吸引力模型”和“容量—车型模型” ,为旅游运输车型配置和合理的组织运输提供理论基础     

Reliability analysis of multi-state repairable system with dynamic transition probabilities

Inadequate maintenance decisions lead to incremental overall costs. In order to minimize costs in maintenance of the multi-state repairable system, we model a preventive maintenance (PM) scheme of the multistate repairable system using non-Markov process. The periodically decreasing reliability model of the non-Markov dynamic system with dynamic transition probabilities is established to satisfy the probability change. The diesel engine system is taken as an example to illustrate the model. The reliability of the diesel engine is analyzed and its PM scheme is worked out. RENO software is used to simulate the diesel engine system. The maintenance cost of components and the optimal PM interval data of the system are obtained by using the minimal average cost as the objective function. The adaptability of PM is judged, and the optimal PM scheme is presented.     

城市管线过河方案设计探讨

通过介绍目前城市管线过河的常用方法,并进行对比分析,得出安全、合理和经济的管线过河方案,可为实际工程提供参考。     

膜离子通道阻断剂对神经兴奋性及兴奋性指标的影响

本研究以蟾蜍坐骨神经-腓神经和螯虾腹大神经为材料,观察了膜离子通道阻断剂对神经兴奋性及兴奋性指标的影响。结果显示:标准电量α与膜钠离子通道的开放数量及通道的激活速率有关,是正确反映兴奋性的指标。b 反映了膜钠、钾离子通道活动的动态平衡过程和应激活动过程.Chr 与膜离子通道的活动无直接联系。     

Inspection-Based Policy Considering Human Errors for Three-Stage Delay Time Degradation Systems

A periodic inspection policy for a single component system based on a three-stage failure process is proposed, and two different kinds of failures covering “hard” and “human” are considered in the proposed policy. The system is periodically inspected and inspections are perfect so that they can identify the intended defect. If the severe defect is detected by an inspection, an immediate repair is needed. However, once the system is identified to be in the minor defective state, there are two options. The first is to do nothing till the arrival of identifying the severe defect or hard failure, and the second is to repair immediately. Repair for any defect can renew the system with a limited probability such that the system may fail after repair due to human errors, which is common in many industrial applications. Two models are constructed by minimizing the expected cost per unit time and compared. We provide a numerical example to demonstrate the proposed model.