Improving rail network velocity: A machine learning approach to predictive maintenance

Rail network velocity is defined as system-wide average speed of line-haul movement between terminals. To accommodate increased service demand and load on rail networks, increase in network velocity, without compromising safety, is required. Among many determinants of overall network velocity, a key driver is service interruption, including lowered operating speed due to track/train condition and delays caused by derailments. Railroads have put significant infrastructure and inspection programs in place to avoid service interruptions. One of the key measures is an extensive network of wayside mechanical condition detectors (temperature, strain, vision, infrared, weight, impact, etc.) that monitor the rolling-stock as it passes by. The detectors are designed to alert for conditions that either violate regulations set by governmental rail safety agencies or deteriorating rolling-stock conditions as determined by the railroad.Using huge volumes of historical detector data, in combination with failure data, maintenance action data, inspection schedule data, train type data and weather data, we are exploring several analytical approaches including, correlation analysis, causal analysis, time series analysis and machine learning techniques to automatically learn rules and build failure prediction models. These models will be applied against both historical and real-time data to predict conditions leading to failure in the future, thus avoiding service interruptions and increasing network velocity. Additionally, the analytics and models can also be used for detecting root cause of several failure modes and wear rate of components, which, while do not directly address network velocity, can be proactively used by maintenance organizations to optimize trade-offs related to maintenance schedule, costs and shop capacity. As part of our effort, we explore several avenues to machine learning techniques including distributed learning and hierarchical analytical approaches.     

深水碎石整平系统整平试验研究

对深水碎石整平系统进行介绍,分析了整平系统的核心装备——抛石整平头的各项性能,并给出了对应的定性与定量的分析。介绍了整平系统位于半潜驳上的刮平试验情况,对试验数据进行了分析。此试验采用西门子PLC,集合以太网通讯技术,采集GPS高程参数,采用位置算法,集成了防超差功能,对抛石头油缸进行了自动同步精度控制。试验结果表明抛石系统满足设计要求,该系统的分析可为此类工程系统的设计与制作提供参考。     

Modeling design of military equipment operational concepts by MBSE北大核心CSCD

［Objectives］In order to give full play to role of "operational concepts" in the engineering process of military equipment development, it is necessary to understand and form standardized operational concept documents (OCD), and study the modeling design of OCD in order to implement the transformation of the system engineering process from document-centric to model-centric. ［Methods］This study analyzes the US military's definition of operational concepts and introduces its hierarchical operational concepts, especially the bottom level ConOps or OpsCon, usually as a part of equipment acquisition and requirement engineering. Lessons are then drawn from the relevant theories and standards such as IEEE 29148:2018 and ANSI/AIAA G-043B-2018 of the operational concepts document outline in order to design the specifications of the OCD. Finally, key technologies are studied, including SysML-based OpsCon modeling, UML Profile-based OpsCon framework design and MSDL/C-BML-based operational scenario development.［Result］The results indicate the effectiveness of implementing the modeling design of OCDs. ［Conclusions］In the process of equipment requirement engineering, the results of this study can help to improve the efficiency of equipment requirement demonstration through an ambiguous operational concept model and an engineering environment for all stakeholders of the system. © 2022 Journal of Clinical Hepatology. All rights reserved.     

城市轨道交通全自动一体化智能运行系统研究

在全自动运行系统迅速普及与互联互通发展需要的背景下,城市轨道交通运营场景日益复杂,运行控制系统的智能化、一体化与自动化趋势日益显著。基于此,本文提出了城市轨道交通全自动一体化智能运行系统的基本内涵,讨论了系统的基本功能与业务功能关系,分析了系统体系架构与跨线网系统架构,并探讨了系统的性能指标。     

百隆高速公路K116＋670滑坡治理及效果评价

文章针对百隆高速公路百色水利枢纽库区段K116＋670滑坡工程地质及水文地质基本情况,结合滑坡规模特征及形成机理,从卸载、钢管桩注浆、预应力锚索加固及完善排水系统等方面提出了滑坡治理措施,并通过分析论证了滑坡治理的稳定性和加固治理的效果,同时提出了做好坡面防排水及加强滑坡体工程的建议。     

Assessing social equity in distance based transit fares using a model of travel behavior

The goal of this study is to develop and apply a new method for assessing social equity impacts of distance-based public transit fares. Shifting to a distance-based fare structure can disproportionately favor or penalize different subgroups of a population based on variations in settlement patterns, travel needs, and most importantly, transit use. According to federal law, such disparities must be evaluated by the transit agency, but the area-based techniques identified by the Federal Transit Authority for assessing discrimination fail to account for disparities in distances travelled by transit users. This means that transit agencies currently lack guidelines for assessing the social equity impacts of replacing flat fare with distance-based fare structures. Our solution is to incorporate a joint ordinal/continuous model of trip generation and distance travelled into a GIS Decision Support System. The system enables a transit planner to visualize and compare distance travelled and transit-cost maps for different population profiles and fare structures. We apply the method to a case study in the Wasatch Front, Utah, where the Utah Transit Authority is exploring a switch to a distance-based fare structure. The analysis reveals that overall distance-based fares benefit low-income, elderly, and non-white populations. However, the effect is geographically uneven, and may be negative for members of these groups living on the urban fringe.     

内容教学法在高职英语教学中的应用

本文介绍了英语教学中一种新的教学思路——内容教学法。它强调通过内容学习来提高语言技能。在我院大学英语改革中，我们将内容教学法引人大学英语课堂，取得了良好的教学效果。     

基于GSQA设备的车辆换档性能测试分析

为将车辆的换档性能主观评价数据化,准确地找出车辆换档性能的差距和不足,本文介绍一种车辆换档性能的客观评价方法,并对其测试的方法和步骤进行说明,最后对测试结果进行分析。     

集装箱场桥发动机双速节能装置的研制

集装箱场桥在作业中存在待机空耗的情况。针对此问题,提出了场桥进行双速发电改造的方案,以满足场桥生产终端等必要用电设备的不间断供电。介绍了双速发电装置和该装置节能的原理,并介绍了改装后的使用效果。     

电动助力转向器的设计要求

为了促进国家标准或行业标准的旱日制定，文章提出了电动助力转向器的一些设计方面的要求。介绍了电动助力转向器的结构，阐述了其基本性能、工作环境及安全性要求，表明电动助力转向器具有结构简单、动力消耗小和节约能源等显著优势。指出目前国内许多自主品牌轿车都已安装了自己研发的电动助力转向器，其蓬勃的发展势头必将使电动助力转向器取代液力助力转向器成为可能。