瑞雷波法检测路基压实度的应用研究

介绍了瑞雷波频散计算原理,围绕时距(X-T)域的面波、波频(F-K)的面波和面波的频散特征,详细介绍了瑞雷面波频信号的处理步骤。结合工程实例,分别采用瑞雷波法和环刀法对该路段路基压实度进行检测和对比分析,探讨瑞雷波法检测路基压实度的应用特点及规律,结果表明,二者均取得一致性较好的检测效果,通过瑞雷波方法获取的频散曲线更能如实反映路基压实效果。     

省级高速公路管理体制研究

本文在总结国内外高速公路管理体制的基础上，确定了各省市高速公路网络管理体制规划的原则，提出了三种主要的推荐管理模式。     

新型SVCT系列磁调制电压传感器

通过磁性材料研究确定高导磁环镍铁合金(1J77)的B-H曲线,分析其在方波电压激励下的工作过程,论证其有较快的响应时间。介绍SVCT系列磁调制电压传感器在直流、低频和高频测量下不同的工作原理,并以SVCT.1000B产品为例进行分析。该产品性能参数满足实际应用需求,同时已经通过常规环境可靠性和电磁兼容可靠性试验。     

隧道弃渣质路基回弹模量的检测探究

本文重点介绍了路基回弹模量PFWD现场快速检测法,结合贝克曼梁法及现场承载板法,对案例隧道弃渣质路基进行了现场回弹模量测试,并展开对比分析,以为同类工程检测应用提供技术参考。     

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.     

Multi-Criteria Decision Making Based on Correlation Coefficient of Triangular Intuitionistic Fuzzy Numbers

We study a multi-criteria fuzzy decision-making method based on weighted triangular intuitionistic fuzzy number correlation coefficients. Under the scenario that criteria weights for alternatives are completely unknown, triangular intuitionistic fuzzy method can not only supplement the insufficiency of the method based on the distance but also endow more information to the estimation and reduce the loss of evaluation information.Among the triangular numbers, two boundary numbers are the maximum and minimum values of the interval respectively, and the medium number is the most possible value under subjective estimation. Using this method,we propose a new way to obtain the criteria weights with more information quantity. By ranking the relative closeness of the weighted correlation coefficients between each alternative, and the critical and ideal alternatives,we show the method to figure out the most suitable alternative based on the expected criteria. An illustrative example is also taken into account to prove the effectiveness of the model.     

Optimal inspection and replacement strategy for systems subject to two types of failures with adjustable inspection intervals

The inspection activities are often carried out to detect possible indication of failures in plant systems. This paper considers a single unit system subject to two types of failures, where one failure mode is the traditional 0-1 logic failure and the other failure mode is described by a two-stage failure process. Adjustable inspections are used to detect the defective stage of the latter. We assume that the inspection duration gets shorter and shorter with a constant ratio. At the same time, preventive replacement is used to avoid the possible failure due to the former failure mode. The renewal process of this system is analyzed and the expected long-run cost per unit time (ELRCUT) is derived. The optimal inspection period and the preventive replacement interval to minimize ELRCUT are studied. At last, a numerical example is presented to illustrate the proposed model.     

智能网联异质交通流混合特性

为研究车联网环境下异质交通流的演变规律,基于改进的NaSch模型,针对智能网联化程度的前期、中期和后期分别进行仿真实验,得到交通流基本图,并分析通行能力与网联车渗透率的内在联系;其次,通过马尔可夫链证明了网联车形成的有序排列能提高道路通行能力,随机仿真实验验证了理论推导的正确性;最后,引入考虑车辆排列方式的相对熵,从而定量描述异质车流的有序性,阐明了智能网联车辆（connected and autonomous vehicle,CAV）改善交通状况的本质原因. 研究结果表明:随着智能网联车渗透率的增加,通行能力增加,在智能网联化前期,渗透率的增加对通行能力提升较小,最高仅提升23.5%,中、后期通行能力最高能提升125.0%;在一定交通密度下,CAV渗透率与流量呈现正相关,相对熵与流量呈现负相关;智能网联车处于分离态时相对熵较小,分离态对随机混合的通行能力的提升随着CAV渗透率的增加而降低.      

Software Reliability Growth Model Considering First-Step and Second-Step Fault Dependency

As one of the most important indexes to evaluate the quality of software, software reliability experiences an increasing development in recent years. We investigate a software reliability growth model(SRGM). The application of this model is to predict the occurrence of the software faults based on the non-homogeneous Poisson process(NHPP). Unlike the independent assumptions in other models, we consider fault dependency. The testing faults are divided into three classes in this model: leading faults, first-step dependent faults and second-step dependent faults. The leading faults occurring independently follow an NHPP, while the first-step dependent faults only become detectable after the related leading faults are detected. The second-step dependent faults can only be detected after the related first-step dependent faults are detected. Then, the combined model is built on the basis of the three sub-processes. Finally, an illustration based on real dataset is presented to verify the proposed model.     

Optimal Preventive Maintenance Policy with Consideration of Production Wait

In this paper, we consider the replacement of a single unit with catastrophic failure mode. Besides replaced at a preset time, the unit is also replaced at failure time or if it encounters a production wait and its age has reached a threshold. The joint preventive maintenance interval and threshold optimization problem are formulated with the objective of minimizing the expected cost per unit time in long run. A numerical example is presented to illustrate the applicability of the model.