bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular recognition in myxobacterial outer membrane exchange: functional, social and evolutionary implications
Authors: Wall Daniel
Published: November 2013

Through cooperative interactions, bacteria can build multicellular communities. To ensure that productive interactions occur, bacteria must recognize their neighbours and respond accordingly. Molecular recognition between cells is thus a fundamental behaviour, and in bacteria important discoveries have been made. This MicroReview focuses on a recently described recognition system in myxobacteria that is governed by a polymorphic cell surface receptor called TraA. TraA regulates outer membrane exchange (OME), whereby myxobacterial cells transiently fuse their OMs to efficiently transfer proteins and lipids between cells. Unlike other transport systems, OME is rather indiscriminate in what OM goods are transferred. In contrast, the recognition of partnering cells is discriminatory and only occurs between cells that bear identical or closely related TraA proteins. Therefore TraA functions in kin recognition and, in turn, OME helps regulate social interactions between myxobacteria. Here, I discuss and speculate on the social and evolutionary implications of OME and suggest it helps to guide their transition from free‐living cells into coherent and functional populations.
Contextualising Causation Part I
Authors: Reiss Julian
Published: November 2013

This is the first instalment of a two‐part paper on the counterfactual theory of causation. It is well known that this theory is ridden with counterexamples. Specifically, the following four features of the theory suffer from problems:

it understands causation as a relation between events;

counterfactual dependence is understood using a metric of similarity among possible worlds;

it defines a non-discriminatory concept of causation; and

it understands causation as transitive.

A number of philosophers have recently proposed that causation is contrastive because making contrasts explicit defuses counterexamples. A contrastive causal claim has the following form: C rather than C*causes E rather than E*, where C*and E*are alternative or contrast events. In this paper, I show that making contrasts explicit does indeed defuse some counterexamples. However, I also argue that the examples discussed in the literature all share a common feature, viz. that the original causal judgement is ambiguous in one way or another. Contrasting does not help with counterexamples that do not have this feature. Part II of this paper then takes up the hard cases.
The replication and critique of libertinism in Andrew Marvell's ‘To His Coy Mistress’
Authors: Cousins A. D.
Published: November 2013

Marvell's ‘To His Coy Mistress’ both iterates and interrogates the discourse of sexual libertinism. His poem presents a double picture of libertine verse and the version of Epicurean philosophy informing it. That picture problematically sets topoi from the literature of sexual libertinism against Christian orthodoxy, refusing to portray their opposition in terms of unqualified polarities. At the last, Marvell leaves his readers to choose between rival visions of the world.
Monetary policy and inflation in South Africa: A VECM augmented with foreign variables
Authors: de Waal Annari , van Eyden Reneé
Published: November 2013

We develop a structural cointegrated vector autoregressive (VAR) model with weakly exogenous foreign variables, known as an augmented VECM or VECX*, suitable for a small open economy like South Africa. This model is novel for South Africa in two ways: it is the first VECX* developed to analyse monetary policy and the first model that uses time‐varying trade weights to create the foreign series. We impose three significant long‐run relations (augmented purchasing power parity, uncovered interest parity and Fisher parity) to investigate the effect of a monetary policy shock on inflation. The results suggest the effective transmission of monetary policy.
A Latent Process Model for Temporal Extremes
Authors: Bortot Paola , Gaetan Carlo
Published: November 2013

This paper presents a hierarchical approach to modelling extremes of a stationary time series. The procedure comprises two stages. In the first stage, exceedances over a high threshold are modelled through a generalized Pareto distribution, which is represented as a mixture of an exponential variable with a Gamma distributed rate parameter. In the second stage, a latent Gamma process is embedded inside the exponential distribution in order to induce temporal dependence among exceedances. Unlike other hierarchical extreme‐value models, this version has marginal distributions that belong to the generalized Pareto family, so that the classical extreme‐value paradigm is respected. In addition, analytical developments show that different choices of the underlying Gamma process can lead to different degrees of temporal dependence of extremes, including asymptotic independence. The model is tested through a simulation study in a Markov chain setting and used for the analysis of two datasets, one environmental and one financial. In both cases, a good flexibility in capturing different types of tail behaviour is obtained.
‘The Ostrich Problem’: Motivated Avoidance or Rejection of Information About Goal Progress
Authors: Webb Thomas L. , Chang Betty P. I. , Benn Yael
Published: November 2013

Monitoring one's current standing with respect to goals can promote effective self‐regulation. However, the present review suggests that there is an ostrich problem such that, in many instances, people have a tendency to “bury their head in the sand” and intentionally avoid or reject information that would help them to monitor their goal progress. For example, people with diabetes avoid monitoring their blood glucose, and few people monitor their household energy consumption, check their bank balances, keep track of what they are eating and so on. While situational constraints can explain some problems with progress monitoring, we use a self‐motives framework to posit that the decision to avoid monitoring often represents the product of an interaction between different motives. For example, the desire to accurately assess progress may conflict with the desire to protect or enhance the self. The present review collates evidence pertaining to the ostrich problem, identifies different motives that underlie the decision to monitor versus not monitor goal progress, illustrates how the ostrich problem might be integrated into models of self‐regulation, and provides suggestions for future research. In so doing, the review advances our understanding of the nature and determinants of intentionally deficient monitoring.
Self‐Affirmation: Understanding the Effects
Authors: Sherman David K.
Published: November 2013

Self‐affirmation theory proposes that individuals possess a flexible self‐system, such that they can respond to threats in one domain of life by affirming self‐worth in other domains. In social psychology research, this has been examined in studies where people affirm important values in the context of self‐threatening events or information. This paper reviews the literature demonstrating the effects of values affirmations and proposes a theoretical account to understand how self‐affirmations reduce defensiveness in response to threats to individuals' health, attenuate physiological stress responses to laboratory and naturalistic stressors, and improve academic performance among individuals experiencing identity threat. The proposed model has three components: Self‐affirmations boost self‐resources, broaden the perspective with which people view information and events in their lives, and lead to an uncoupling of the self and the threat, reducing the threat's impact in affecting the self. This model helps explain what occurs when individuals affirm values in the context of threats, and how self‐affirmations may instantiate lasting effects through changing the nature of ongoing experience.
A One-Dimensional Mathematical Model for Studying the Pulsatile Flow in Microvascular Networks
Authors: Pan Qing , Wang Ruofan , Reglin Bettina , Cai Guolong , Yan Jing , Pries Axel R. , Ning Gangmin
Published: November 2013

Techniques that model microvascular hemodynamics have been developed for decades. While the physiological significance of pressure pulsatility is acknowledged, most of the microcirculatory models use steady flow approaches. To theoretically study the extent and transmission of pulsatility in microcirculation, dynamic models need to be developed. In this paper, we present a one-dimensional model to describe the dynamic behavior of microvascular blood flow. The model is applied to a microvascular network from a rat mesentery. Intravital microscopy was used to record the morphology and flow velocities in individual vessel segments, and boundaries are defined according to the experimental data. The system of governing equations constituting the model is solved numerically using the discontinuous Galerkin method. An implicit integration scheme is adopted to increase computing efficiency. The model allows the simulation of the dynamic properties of blood flow in microcirculatory networks, including the pressure pulsatility (quantified by a pulsatility index) and pulse wave velocity (PWV). From the main input arteriole to the main output venule, the pulsatility index decreases by 66.7%. PWV obtained along arterioles declines with decreasing diameters, with mean values of 77.16, 25.31, and 8.30 cm/s for diameters of 26.84, 17.46, and 13.33 μm, respectively. These results suggest that the 1D model developed is able to simulate the characteristics of pressure pulsatility and wave propagation in complex microvascular networks.
Development of an Integrated Model for the Evaluation and Planning of Railroad Track Maintenance
Authors: Lovett Alexander H. , Dick C. Tyler , Ruppert Conrad , Saat M. Rapik , Barkan Christopher
Published: November 2013

In order for a railroad to function effectively all aspects of the system should be maintained in good working order. Locomotives and rolling stock regularly move through areas where they can be inspected and maintained. However track does not move, so inspectors must traverse the line either on foot or in a rail mounted vehicle and maintenance crews must be sent to specific locations to make track repairs, which may not always happen before a service disruption. A track failure, due to either exceeding some industry or governmental specification or an acute failure, such as a rail break, can result in costly delays or even derailments with significant consequences. To help avoid such failures, it is beneficial for a railroad to be able to predict when and where failures might occur and then evaluate the relative costs and benefits of performing maintenance activities to ensure that the most cost effective actions are taken. A model is being developed to assist in the process of scheduling and directing track maintenance work. The model consists of three primary modules: an integrated track quality and degradation module, a maintenance activity selection module, and a scheduling optimization module. By taking into account a wide range of costs and benefits, the model can help railroad infrastructure managers better account for risk and indirect costs such as track time, as well as account for the criticality of certain types of imminent failures. This paper will describe the inputs and outputs for the model, as well as detailing the concepts associated with each of the model components.
Adapting Dynamic Braking of AC Motors to Varying Wheel/Rail Adhesion Condition
Authors: Ahmad Husain , Ahmadian Mehdi
Published: November 2013

Model reference adaptive control (MRAC) is developed to control the electrical excitation frequency of AC traction motors under various wheel/rail adhesion conditions during dynamic braking. More accurate estimation and control of train braking distance can allow more efficient braking of rolling stock, as well as spacing trains closer together for Positive Train Control (PTC). In order to minimize the braking distance of a train, dynamic braking forces need to be maximized for varying wheel/rail adhesion. The wheel/rail adhesion coefficient plays an important role in safe train braking. Excessively large dynamic braking can cause wheel lockup that can damage the wheels and rail, or may lead to large coupler forces, possibly causing derailment or broken components. In this study, a multibody formulation of a locomotive and three railcars is used to develop a model reference adaptive controller for adjusting the voltage excitation frequency of an AC motor such that the maximum dynamic braking is achieved, without locking up the wheels. A relationship between creep forces, creepages, and motor braking torque is established. This relationship is used to control the motor excitation frequency in order to closely follow the reference model that aims at achieving maximum allowable adhesion during dynamic braking. The results indicate that MRAC significantly improves braking distance while maintaining better wheel/rail adhesion and coupler dynamics during dynamic braking.
Enterprise Architecture: System and Management Framework for NYCT Vital Systems
Authors: Georgiadis Sofia K. , Comba Andrew
Published: November 2013

The concept of operations for NYCT systems is changing as a result of Automatic Train Supervision (ATS) Communications-Based Train Control (CBTC), and Solid State Interlocking (SSI) deployment. Train dispatchers are dealing with a higher degree of automation with ATS systems; and similarly, train operators are adjusting to a split between automated and manual processes with CBTC systems. The emerging CBTC and SSI systems are becoming Information Technology (IT) infrastructure and digital-control based. While CBTC is increasing the overall safety of the signaling system, it is also increasing system complexity, especially from an analysis point of view. These issues are addressed at NYCT by the implementation of DoDAF, which the U.S. Department of Defense Architecture Framework, an Enterprise Architecture.

This paper discusses VSI’s application of DoDAF with a focus on the safety certification mission. It begins with an overview of DoDAF, followed by a description of Views and Product-models, the building blocks of DoDAF. Each section presents a high-level description of each View, along with exemplary Product-model descriptions, 1 or 2 per View. In addition, two system capability requirements, Safe Train Separation and Control Speed to Restriction Limits, are examined and mapped throughout the model.
Quantitative Measurement of Pantograph Loss of Contact Dynamics
Authors: Ku Bih-Yuan , Liu Jen-Sen , Ko Ming-Jan
Published: November 2013

In this paper we present our work on the development of a quantitative measurement advice to capture the dynamics of pantograph arcing during loss of contact. Despite the difficulties involved, it is very important for the railroad operators to accurately measure the pantograph loss-of-contact dynamics in order to assess the current collection quality of the pantograph with the overhead contact system during the commissioning phase and long-term operation. We use photovoltaic cells to construct a simple but effective sensor that can produce a voltage signal proportional to arc strength and duration, which can then be used as a precise quantitative measure of the loss of contact dynamics of the pantograph.
Evaluating the Results and Features of Two Capacity Simulation Tools on the Shared-Use Corridors
Authors: Lautala Pasi , Pouryousef Hamed
Published: November 2013

The majority of passenger rail services in the United States (U.S.) operate on the shared-use corridors with freight rail. These types of operations tend to be challenging due to high heterogeneity, particularly in terms of reliability of service and capacity availability. The projected growth in demand for rail transportation is likely to exacerbate the situation. Similar to the U.S., the European passenger rail services are generally operated on shared-use corridors, but the infrastructure conditions and the operational priorities and patterns typically allow more reliable and higher speed passenger operations in comparison to the U.S. trains.

Both continents use capacity and simulation software to analyze capacity allocations and operational limitations. However, the effects of the software selection haven’t been investigated. This research reviews two common simulation tools developed in the U.S. and Europe, Rail Traffic Controller (RTC) and Railsys, respectively. The paper reviews the structure and the main components of these two simulation tools. It will also present the outcomes of running RTC and Railsys through a given segment of shared-use track based on the same rolling stock, operation and signaling characteristics and analyze the similarities and differences between the outcomes of RTC and Railsys.
RDSP: A Railway Decision Support Platform for Integrating and Bridging Existed Legacy Systems
Authors: Chen I-Chang , Hsu Shu-Keng , Wu Teh-Juan , Yen Li-Hsien , Lee Yusin , Lin Dung-Ying , Chen Chuen-Yih , Lee Wei-Hsun , Su Guo-Wei
Published: November 2013

Railway system operation is a very complicated task and must be supported by the coordination of several systems including engineering, transportation, locomotive maintenance and management, ticket system and passengers service, etc. Ideally, a modern railway enterprise information system should be an integrated, consisted, and site-opened database to support railway system operation. However, multiple isolated applications instead of one integrated enterprise information system are often formed due to historical factors such as independent departments, budgetary constraint and application requirements diversification. Take Taiwan Railways Administration (TRA) as an example, four major departments have their own support systems and databases that store critical planning and operational data. Those systems are isolated and can hardly communicate with each other. As a result, most cross-systems information analyses or data reference for decision making are done manually, which significantly affect the organizational efficiency of TRA.

To address the aforementioned issues, a railway decision support platform (RDSP) for integrating the legacy systems (databases) is proposed in this paper. RDSP is designed to be a railway enterprise information system that supports the critical functions of data warehouse and decision support. Furthermore, RDSP is built by integrating the existing legacy systems rather than by building it from scratch. A data bridging system (HDBS) including four modules are design and implemented, input module for connecting the external data sources, output module for exporting integrated report or dumping data by predefined criteria for other systems, configuration module with a web-based user interface for setting up the periodic operations of data input or output tasks, and DB connection module for connecting external databases. Various types of railway system data are designed in RDSP schema and collected, including facilities, timetable, train services records, tickets, centralized traffic control (CTC) system records, and automatic train protection (ATP) system records.

RDSP provides a system framework to integrate many isolated island-style databases that currently exist in TRA, and can form a cross-enterprise database that serves as the primary and only data platform. To demonstrate the efficacy of the RDSP, a spatiotemporal ticket-selling analysis report, a train delay cause analysis report, and a timetable planning software (TrainWorld) are designed on top of it. In the future, RDSP will play a major supportive role in infrastructure maintenance, operations, decision support, and planning.
Natural Interaction: A Mechanism for Mistake Proofing Operator’s Errors on Trains
Authors: Sawhney Rapinder , Muppaneni Harshitha , Zhang Gewei , Yang Hongbiao
Published: November 2013

Railroad accidents are not only very expensive but also fatal. National Transportation safety data from 2000–2011 indicate staggering numbers — a total of 141 fatalities and 5118 injuries. Filtering Board’s reports on train accidents in last decade point to 28% of fatalities classified as the driver’s fault. The reports also provide that accidents occurring due to operators’ failure amount to a total of $162 million dollars in revenue loss. Most of the accidents caused by operators occur due to miss communication and less response time along with lack of judgment during a crisis situation. Parameters such as Fatigue, reflexes and alertness can be based on many ergonomic factors. Projecting the path of action in advance can assist operators to recognize calamity ahead and prevent them. Software that can enable operators to get trained in a virtual environment with actual control operations in place would be perfect alternative to prepare them for crisis situation in real world. Available train simulator software represents realistic view of operator cab and allows Operators to recreate conditions similar to that encountered in real world. Current work is aimed at enhancing such software with options that can enable operator to integrate alerts, speed changes along the route and have up-to-date traffic information, signal situations and schedule breaks and assists them to act in consequence and function more efficiently to handle crucial situations. This software can also display information, such as operators own position, and relay systems alerts more efficiently, which eliminates miss-communication of operator and control center due to lack of proper radio signals. This enhancement would act as a natural interaction system which is more specific alternative and effective tool for operators with real time data at their fingertips and act as a support system to enable them make fast and accurate decisions. Implementing this software into present systems, can enable better safety through raising operator awareness under tough environment and enhance their safety, resulting in saving loss of revenue along with reduced fatality rates.
Prediction of Railroad Track Foundation Defects Using Wavelets
Authors: Takami Kuya , Taheri Saied , Taheri Mehdi , Furukawa Tomonari
Published: November 2013

This paper presents a novel technique that utilizes wavelet analysis to identify and predict the defects in railroad foundations and rails to prevent derailment or other damages. The proposed defect detection algorithm eliminates the use of wheel and/or track monitoring systems, which are expensive and time inefficient. The algorithm has been validated for the rail crack prediction using only vertical accelerometer signal which accurately detects impending rail breakage while distinguishing the signal generated by special track components such as rail joins and switches. Since the algorithm is flexible, further development can be tailored to detect significantly different rail defects such as track shift and other rail foundation defects. The algorithm is further improved by incorporating SIMPACK dynamic simulation to assist classification of the acceleration signatures. The actual data was then compared to simulation in order to validate the effectiveness of the algorithm.
An Enhanced Optimization Model for Scheduling Freight Trains
Authors: Jaumard Brigitte , Le Thai Hoa , Tian Huaining , Akgunduz Ali , Finnie Peter
Published: November 2013

We propose a new dynamic row/column management algorithm for the schedule of freight trains in a single/double track railway system. While many works have already been devoted to train scheduling, previously published optimization models all suffer from scalability issues. Moreover, very few of them consider the number of alternate tracks in the sidings for train meets, as well as the delay incurred by trains that take sidings. We propose a non time-indexed model, which takes into account such constraints, and we design a solution scheme with iterative additions/removals of constraints/variables in order to remain with a manageable sized mathematical program, while still ensuring convergence to an optimal solution. Numerical results are presented on data instances of Canada Pacific Railway. We evaluate the performance of the optimization model, and the sensitivity of the train schedules to the length of the operation hours, the length of the trains, and the departure times.
Development of a 5-Camera Transfer Length Measurement System for Real-Time Monitoring of Railroad Crosstie Production
Authors: Zhao Weixin , Beck B. Terry , Peterman Robert J. , Wu Chih-Hang John
Published: November 2013

Knowledge of transfer length during production is critical for maintaining continuous production quality in the modern manufacture of prestressed concrete railroad crossties. Traditional laboratory methods for measuring transfer length, using manual instruments such as a Whittemore mechanical gauge or surface mounted resistance-type strain gauge, are simply not suitable for production operation. They are too time-consuming to implement, require extensive surface preparation, and can also require special operator training to provide accurate and reliable surface strain profiles from which the transfer length can be determined in a post-processing manner.

In contrast with earlier manual methods, the newly developed non-contact Laser Speckle Imaging (LSI) technique has been shown to be capable of providing rapid and accurate surface strain measurement and consequently also rapid transfer length assessment. This system has recently been automated and combined with the new Zhao-Lee (ZL) least-squares strain profile fitting technique for quickly and reliably processing surface strain data. The automated system and processing procedure have been shown to provide an improved assessment of transfer length, unhampered by human intervention and subsequent potential human judgment bias.

This paper presents recent progress toward the development of a 5-camera non-contact transfer length measurement system that is capable of continuous monitoring of railroad crossties in a production plant. This is made possible using an optimized version of the previously successful LSI system, which minimizes the number of surface strain measurements required to achieve reliable transfer length assessment. Experimental results and analysis will be presented for the latest multi-camera prototype concept for this new system design, demonstrating that only a few discrete surface strain measurements are required to achieve accurate and reliable transfer length assessment. Thus, for the first time it is now possible to envision practical real-time quality control monitoring of railroad crossties during an in-plant production operation.
A Direct Comparison of the Traditional Method and a New Approach in Determining 220 Transfer Lengths in Prestressed Concrete Railroad Ties
Authors: Zhao Weixin , Beck B. Terry , Peterman Robert J. , Murphy Robert , Wu Chih-Hang John , Lee Grace
Published: November 2013

This paper presents the detailed analysis of surface strain data obtained at six prestressed concrete tie plants in the United States. These data were obtained by the authors by conducting a total of 220 transfer length measurements on prestressed concrete railroad ties with different concrete-mix designs and reinforcement variations.

The surface strain profiles of the railroad ties were obtained using the traditional Whittemore gage, as well as a rapid non-contact technology, called laser-speckle imaging (LSI), that was previously developed by the authors. The LSI technique achieved a microstrain resolution comparable to that was obtained using mechanical gauge technology.

The measured surface strain profiles were then analyzed by both the 95% AMS (95% Average Maximum Strain) method, and the ZL (Zhao-Lee) method that was recently proposed by the authors. The ZL method is an unbiased statistical method that provides a more accurate and reliable transfer length determination. A direct comparison between the 95% AMS method and the ZL method was achieved by applying both methods to determine the 220 railroad tie transfer length values. The comparison confirmed the bias of the 95% AMS method in estimating transfer length value, as predicated by theoretical analysis.
Modeling Empty Intermodal Flatcar Distribution in an U.S. Class I Railroad
Authors: Pranoto Yudi , Yoon Hyun-suk , Cheng Clark
Published: November 2013

In this paper, we discuss an effort to develop optimization models to distribute intermodal flatcars in an U.S. Class I railroad. The models were developed as strategic and tactical tools. We discuss model complexity and results.
Abandoned Freight Rail Corridor Reuse Examples From Texas
Authors: Morgan Curtis , Warner Jeffery
Published: November 2013

This paper highlights many varied reuse examples for abandoned freight rail corridors within the state of Texas, including for highway development, transit development, recreational trails, and for resumption of freight rail service. Several case studies present these examples. This paper also describes the extent to which abandoned rail lines in the state have been lost through abandonment and discusses the importance of preserving such corridors intact, when possible, for future transportation needs should any become available in the future.
TrainWorld: A Powerful Tool for Railway Timetabling
Authors: Chen I-Chang , Hsu Shu-Keng , Hsu Hsiu-Hao , Chen Chuen-Yih , Lin Dung-Ying , Lee Wei-Hsun , Lee Yusin
Published: November 2013

Planning for the operation of a railway system is a very complicated task. At the center stage of this planning work is timetabling. In this work we present TrainWorld, a powerful, sophisticated software system that, among other capabilities, is able to solve for high-quality timetables for real-sized, complicated railways. Testing with Taiwan Railways Administration (TRA) data demonstrates the ability of TrainWorld in solving for real-world timetables. The TRA system has 224 stations, approximately three-quarters of the 1085Km railway are double-tracked, and the rest are single-tracked. The system offers close to 1000 daily services in its 18-hour operation hours. Some busy stations carry more than 280 services a day, resulting in an eight-minute average headway between trains. TrainWorld is able to solve a timetable for such a system in approximately 70 hours, and the result is close to the real timetable.
Highway Crossing Control Using PTC Technology
Authors: Thurston David F.
Published: November 2013

Positive Train Control (PTC) was mandated by Congress in 2008 to be installed on an extensive network of rail carriers within the United States before the end of 2015. As such, the short time frame for implementation has dictated that several key features that could be adopted within the train control area not be considered until the base development is finished. One of the areas that has been pushed off until later is the interface to Highway crossings. This is being explored in part by Caltrain in their Communications Based Overlay Signal System (CBOSS) project that adapts Incremental Train Control System (ITCS) protocols; however this approach does not undertake the full replacement of existing technology.

This paper investigates the concept of operations for PTC controlled highway crossings with the premise that the existing train detection technology will be fully replaced by PTC and its train detection system. This will allow for much reduced hardware in the field while potentially adding additional functionality. Detailed analysis of the safety case will be introduced and interface logic will be included. Additional functions such as prediction, preemption, near side control and switching scenarios will be included in the research for both freight and passenger operations and how these situations can be addressed with available PTC technology.
Survey and Examination of Various CBTC Data Communications Subsystems
Authors: Fitzmaurice Michael
Published: November 2013

This paper will survey and describe the various data communication subsystems (DCSs) used on many communications based train control (CBTC) system projects planned and in service throughout North America, Europe and Asia. The paper will focus on the RF characteristics of the DCS so as to highlight the similarities and common challenges that all DCSs face with a view to presenting best practice and innovative design.
Utilization of Ground Improvement for a Variety of Cost Effective Remediation and New Construction Topics for the Rail Industry
Authors: Hill Jeffrey R. , Voor Bernard , Kerr Michael L. , Pengelly Arthur D.
Published: November 2013

The authors of the paper represent two firms that have completed hundreds of challenging subgrade and foundation projects for the rail industry. The intent of this paper is to educate the railroad business in general about alternative approaches to common geotechnical problems facing the railroad industry.

Projects have been completed across the country in nearly all geological conditions, on all of the Class I carriers, Shortlines and Mass Transit systems. Successful remediation projects associated with challenging subsurface conditions across the United States, Canada and Mexico are covered. Case histories include jet grouting for low headroom earth retention and tunnel support, stone columns for embankment support, micropiles for low headroom bridge replacement, micropiles and soil nails for earth retention, compaction, and urethane grouting for settlement of existing structures. Projects discussed include background information such as project layout, drawings and test results. Each project is completed and has a positive track record, indicating success. Projects have been specially selected to demonstrate the ability of specialty foundation solutions applicable throughout North America. Each topic provides technically sound approaches to age-old Rail road subsurface challenges. Many of these topics are not addressed in the AREMA manual; however, one of the authors, is currently addressing these topics through a proposed section of AREMA chapter 8.
Multifunction LIDAR Sensors for Non-Contact Speed Measurement in Rail Vehicles: Part 2 — Data Collection and Analysis
Authors: Wrobel Shannon , Ahmadian Mehdi , Craft Michael , Munoz Josh
Published: November 2013

The application of Doppler based, LIght Detection And Ranging (LIDAR or lidar) technology for measuring true ground speed in a non-contacting manner is investigated, as a replacement to wheel tachometers that are commonly used for such measurements. Measuring track speed and distance traveled is an essential part of rail geometry measurement systems. Wheel tachometer measurement accuracy can often be adversely affected by wheel vibrations, change in wheel diameter, and wheel slip in high traction conditions. LIDAR is a non-contact measurement device that uses the Doppler technology to accurately determine speed. Two LIDAR sensors are attached to the underside of a track geometry car with the sensors’ Class I laser beams facing the gauge corner of each rail. The LIDAR sensors measure the absolute ground speed for each rail, allowing for the determination of forward speed and track curvature. The results of the tests show high accuracy in LIDAR speed, distance, and track curvature measurements when compared with other conventional means that are used in the railroad industry and ground truth measurements. With further development, LIDAR sensors can replace wheel tachometers that are commonly used for speed and distance measurement, therefore eliminating the problems with mechanical reliability and the need for periodic calibration of wheel tachometers.
Cases Study on the Acceptance Disputes of Taiwan MRT E&M Systems From the Perspective of Risk Allocation
Authors: Hsu Ko-Ming , Yeh Frank , Hsieh Ting-Ya
Published: November 2013

Rail construction is an essential part of the Taiwan transportation projects. Since the mass rapid transit systems are powering by electricity, the successful installation of rail work built under the core electrical & mechanical system is also the key factor of the transit system integration. For cases discussed in this research, since the client needed to apply these contracts of civil laws after the completion yet before acceptance, two problems might be generated under such circumstances: 1) if there was any matter which could not be imputed on either party caused the failure of the contract, which party should be responsible for the result; 2) if there was any cease of operation or casualties and other damages during the verification of system stability and availability, which party should be responsible. The resolve of these problems was in fact a result of risk allocation through contracts. Due to that the risk allocation principals might vary due to the prediction and planning of different parties, based on the contractual freedom idea in Taiwan, if we wish to pursue the risk allocation, this reach point out the procedures it should be. From the case study of this research, it could be seen that one applicable idea of risk distribution, yet in the verification of individual cases, there would be concerns for different ideas due to specific abstract risk allocation ideas. There might be further research into the detailed standards for risk allocation to resolve the potential doubt.
Railway Project Integration Engineering: New Methodology
Authors: Donohue Brian P.
Published: November 2013

In November, 2005 before an assembly of rail transit managers and engineers, keynote speaker Tom Prendergast — then Vice President, Parsons Brinckerhoff T&RS — declared that the next frontier of railway engineering would be not in the “Big Four” engineering disciplines of Civil, Mechanical, Electrical or even Computer Engineering, but in “Integration Engineering.” Years have passed and while Tom’s words have not yet been fully realized by the transit industry, change is happening.

Today, railway construction projects that have had major construction issues include the now beleaguered Edinburgh, Scotland “Edinburgh Tram” and the recently opened Hampton Roads Transit “Tide” Light Rail. Both projects have suffered from major cost overruns, work stoppages and legal entanglements, much of which can be attributed to a lack of scope clarity, especially utility identification & interfaces, and utility relocations. The lack of coordination for both projects can be traced back to the preliminary engineering level and continued, unchecked through final design and into construction where the lack of coordination and planning was realized too late. [1,2]

Given the complexities of modern railway systems and the well-developed urban and suburban infrastructure where they are typically built, proper integration engineering is essential from the earliest phases of a project and should be carried through to the start of revenue operations and maintenance. There are however, examples of recently completed railway projects that have addressed project integration engineering successfully, finishing ahead of schedule, ahead of budget, or both.

This paper is a continuation in a short series of presentations and papers that will address Railway Project Integration Engineering as a topic and recommend the integration tasks deemed critical to a successful project. The primary subject matter will be the Denver Eagle P3 — the first rail transit Public Private Partnership (P3) in the United States that has recently completed final design and is currently under construction. The materials and techniques to be presented are relatively new, and have already been used successfully in Europe. Should they prove successful with the Eagle P3, this could lower both cost and risk for future North American rail projects.

This first paper will discuss the topic, review modeling techniques that were used to define the project integration process, and will capture the results of final design integration with both successes and difficulties. This paper will also cover the early stages of the Eagle P3 project construction, tie into the model, and attempt to project likely results when construction concludes and testing begins with the ultimate goal of meeting an ambitious schedule and budget when operations commence in January, 2016.
Designing Rail Vehicle Suspensions for Reducing Track Dynamic Loading
Authors: Meymand Sajjad Z. , Ahmadian Mehdi
Published: November 2013

This paper presents the results of a study to evaluate the effect of semiactive dampers in reducing track dynamic loading at the interface between the rail and moving wheel in rail vehicles. Considering an elastic foundation for the track, the study derives a simplified dynamic model for a railcar primary suspension, attached to the wheelset (unsprung mass) and car body (sprung mass). The performance of the system for different semiactive control strategies is presented and compared with conventional passive suspensions. Different system excitations, caused by track irregularities, are considered and the performance of the system is investigated in both time and frequency domains. Simulation results show that displacement-based groundhook control strategies can reduce the dynamic loads caused by the moving wheel in the vertical direction, therefore lessening the track damage caused by high wheel loads.
Boiler Wall Protection With Rear Ventilated Refractory Tiles
Authors: Mulch Stephan
Published: November 2013

The prevention of corrosion on boiler tube-walls has been a most difficult and cost intensive problem in WTE plants. This is specifically the case where the incineration boilers are operating with increased saturated steam temperatures and their corresponding pressures. In addition, variations in the garbage mixtures, with differing values of chemical content and varying waste composition give importance to the prevention of boiler tube corrosion. Several refractory lining systems and types have been installed over the previous 80 years and can be compared. In the early stages it began with simple concrete installations and only later was it developed to use heat resistant ceramic products, now essentially silicon carbide. 20 years ago cement or chemically bonded SiC monolithics (gunning, trowelling or casting materials) were usually installed to protect boiler walls, but today fabricated and fired SiC tiles, with their enhanced properties, are mainly used. A distinction is made between hanging and bolted tiles, as well as between oxide bonded and nitride bonded SiC material and between mortared, backfilled and rear ventilated tiles. All these systems were carefully examined and assessed. It proved possible to develop a revolutionary heat conduction and corrosion protection system utilising air. An air gap between the refractory SiC tiles and the boiler wall proved to be both simple and successful. By means of detailed and systematic documentation and monitoring, including J + G’ s “Air” tiling system, it has, for a few years, been possible to offer and recommend long lasting refractory linings with the aim of protecting boiler walls against corrosion, reducing operating costs and using the energy of the waste in an optimum manner.
Innovative Concepts of Conversion and High Efficiency Using MARTIN Technology
Authors: Koralewska Ralf
Published: November 2013

Thermal treatment of waste using grate-based systems has gained world-wide acceptance as the preferred method for sustainable management of residual waste. However, in order to maintain this position and respond to new challenges and/or priorities, it is necessary to further develop innovative concepts that use safe process engineering technology in terms of climate and resource protection as well as reduction of environmental impacts. MARTIN, in collaboration with research institutes, successfully developed and optimized a multi-stage combustion process in the 1990s. Various pilot and full-scale studies and tests followed. Based on this knowledge, MARTIN and its cooperation partners COVANTA ENERGY (USA), CNIM (F) and Mitsubishi Heavy Industries (JP) developed the Very Low NOx (VLN) process as a large-scale primary measure for NOx reduction. MARTIN’s next step was to develop the Very Low NOx gasification mode (VLN-GM) process. This process has been implemented directly in continuous operation at an industrial-scale Energy-from-Waste (EfW) plant in Switzerland. In VLN-GM operation, the excess air rate in the gas above the grate is decreased from λ = 1.2 to about 0.8.

The characteristics of municipal solid waste make it suitable for the generation of heat and power. While boiler concepts implemented in the past often focused on factors such as high availability, reduced downtimes and minimized maintenance costs, measures to increase the efficiency of the overall process are also growing in importance. Energy efficiency can be increased by optimizing boiler efficiency itself on the one hand, and on the other hand by improving peripheral plant devices, in particular by improving energy recovery through changes in the steam parameters.

MARTIN has developed corrosion-protected wall and radiant superheater solutions, located in the upper furnace area, and installed these as prototypes in full-scale plants. As a result, steam can be heated about 35 °C (90 °F) in excess of the current state-of-the-art parameters without adversely affecting plant operation due to superheater corrosion.

This paper documents that innovative concepts using MARTIN technology successfully provide solutions for a grate-based conversion technology (VLN-GM) as well as measures for increasing the energy efficiency of Energy-from-Waste plants.
Managing Food Waste With Anaerobic Digesters: Is This a Greener Technology Than Conventional WTE
Authors: LoRe Anthony M. , Hurdle Robert L.
Published: November 2013

Recent attention in the North American market has focused on managing food waste biologically using anaerobic digestion (AD) technology, which produces a biogas that can be used to generate electricity and a digestate or residue that can be used as a fertilizer, or composted and used as a soil amendment. The increased focus on AD is driven by the desire to increase waste diversion rates and a perception that AD is a “greener” approach to managing food waste than landfilling or conventional waste-to-energy (WTE) technology. Policy makers in some cases have already concluded that AD of source separated organics is preferable to landfilling and WTE. While the environmental benefits of AD over landfilling are obvious, especially for landfill sites without active gas collection systems, the benefits are less clear when compared to conventional WTE technology since relatively little analysis has been performed to date.

Two environmental considerations often associated with being a “green technology” are energy recovery potential and greenhouse gas generation. This paper examines the amount of energy that can be produced by treating food waste biologically using AD compared to treating the same material thermally using mass burn WTE, which is the most commonly used WTE technology. The impact on net greenhouse gas emissions, namely carbon dioxide generation, from each technology is also compared taking into account a variety of factors including differences in the percentage of the feedstock carbon converted to carbon dioxide, the amount of fossil fuel avoided as a result of power generation, and the amount of vehicle emissions associated with collection and transportation of source separated food waste. This paper also compares other important considerations such as capital and operating costs, residuals management, and odor control.