In this dissertation, we have developed computer vision methods for measurement of rail gauge, and reliable identification and localization of structural defects in railroad tracks. The rail gauge is the distance between the innermost sides of the two parallel steel rails. We have developed two methods for evaluation of rail gauge. These methods were designed for different hardware setups: the ...

the planning of a rail transit system is a complex process involving the determination of station locations and rail line alignments connecting the stations. There are many requirements and constraints to be considered in the planning process, with complex correlations and interactions, necessitating the application of optimization models in order to realize reliable and cost-effective rail tra...

Using multiple independent networks (also known as rails) is an emerging technique to overcome bandwidth limitations and enhance fault-tolerance of current high-performance clusters. This report presents the limitations and performance of static rail-allocation approaches, where each rail is pre-assigned a direction for communication. An analytical lower bound on the number of networks required...

The present work has been carried out to study the sensitization behavior of AISI 304L austenitic stainless steel weld, fabricated using GTAW (gas tungsten arc welding process). This weld was subjected to post weld thermal aging (PWTA) treatments lying in the sensitization range, viz. 700 ?C for 30 minutes, 500 minutes and 1000 minutes for studying the influence of carbide precipitation on thei...

This paper introduces a novel method for the quality evaluation of resistance spot welds. The evaluation is based on computer vision methods, which allow nondestructive on-line real-time processing. The input of the system is the image of a weld imprint on a metal band which covers the electrodes against wear and soiling. In order to find the position of the resistance spot welds, we describe a...

As state transportation planners seek to build or support sustainable transportation systems in an era of economic challenges, they find few publicly available rail analysis models for stakeholders to examine the environmental impacts, socio-economic effects and costs associated in investing in rail infrastructure. This paper, taken from a University Transportation Center Program (UTCP Region 6...

This report evaluates criticism of rail transit systems. It examines claims that rail transit is ineffective at increasing public transit ridership and improving transportation system performance, that rail transit investments are not cost effective, and that transit is an outdated form of transportation. It finds that critics often misrepresent issues and use biased and inaccurate analysis. Th...

This paper describes a threefold method of testing the performance of an array-based ultrasonic tool for nondestructive testing of spot welds. The tool is described in its capabilities, use, and advantages over existing counterparts. Performance testing is not only described, but results from carrying out the testing are documented as well. The three performance testing methods include the use ...

the aim of this paper is to characterize welding of aisi 310 austenitic stainless steel to inconel 657 for use in oil-refining industries. the welds were produced using four types of filler materials; nickel-based alloys designated as inconel 82, a, 617, and 310 ss. the interfaces and heat-affected zones were characterized by optical and scanning electron microscopy. interfaces on the two sides...

The corrosion behavior of the fusion zone of gas tungsten arc (GTA) welds of AA6061 alloy was studied. Role of gas tungsten arc welding techniques such as continuous current (CC) and pulsed current (PC) and reference filler (AA5356) were studied. Role of different grain refiners such as scandium, zirconium and Tibor in the reference filler was studied. Dynamic polarization testing was used to d...