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 ...

We consider the Navier-Stokes equation in a domain with rough boundaries. The small irregularity is modeled by a small amplitude and small wavelength boundary, with typical lengthscale ε ¿ 1. For periodic roughness, it is well-known that the best homogenized (that is regular in ε) boundary condition is of Navier type. Such result still holds for random stationary irregularities, as shown recent...

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 purpose of the following paper is to present author’s experimental field investigations a jointless railway track subjected generated imperfection and analysis response applied static loads. An optical measurement system, Pontos, was used for dynamic track’s deflections in 3D. allow us recommend direct application this system non-contact measurement, visualization simulated defects track, a...

Interaction of charged particles with each other and/or with external fields results in emission of electromagnetic radiation. This article considers the emission arising as fast (nonthermal) particles move through media with random inhomogeneities. The nature of these inhomogeneities might be rather arbitrary. One of the simplest examples of inhomogeneities is a distribution of the microscopic...

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...

Presented is a 0.9 V rail-to-rail constant gm CMOS amplifier input stage consisting of complementary differential pairs and a gm control circuit. The gm control circuit eliminates the gm dead zone, which occurs in the conventional rail-to-rail amplifier with ultra-low supply voltages. The proposed amplifier input stage has a constant gm that varies by +2.3% for rail-to-rail input common-mode le...