bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic Performance of Myocardial Innervation Imaging Using MIBG Scintigraphy in Differential Diagnosis between Dementia with Lewy Bodies and Other Dementias: A Systematic Review and a Meta‐Analysis
Authors: Treglia Giorgio , Cason Ernesto
Published: November 2010

BACKGROUND AND PURPOSE

This study was designed to review the diagnostic performance of myocardial innervation imaging using iodine‐123‐metaiodobenzylguanidine (MIBG) scintigraphy in differential diagnosis between dementia with Lewy bodies (DLB) and other dementias.

METHODS

A comprehensive computer literature search of studies published through May 2010 regarding MIBG scintigraphy in patients with DLB was performed in PubMed/MEDLINE and Embase databases. Only studies in which MIBG scintigraphy was performed for differential diagnosis between DLB and other dementias were selected. Pooled sensitivity and specificity of MIBG scintigraphy were presented with a 95% confidence interval (CI). The area under the ROC curve was calculated to measure the accuracy of MIBG scintigraphy in differential diagnosis between Lewy body diseases and other dementias.

RESULTS

Ultimately, we identified 8 studies comprising a total of 346 patients with dementia (152 patients with DLB and 194 patients with other dementias). The pooled sensitivity of MIBG scintigraphy in detection of DLB was 98% (95% CI, 94‐100%); the pooled specificity of MIBG scintigraphy in differential diagnosis between DLB and other dementias was 94% (95% CI, 90‐97%). The area under the ROC curve was .99.

CONCLUSIONS

Myocardial innervation imaging with MIBG scintigraphy demonstrated high pooled sensitivity and specificity in patients with suspected DLB. MIBG scintigraphy is an accurate test for differential diagnosis between DLB and other dementias. J Neuroimaging 2012;22:111‐117.
Acute White Matter Differences in the Fornix Following Mild Traumatic Brain Injury Using Diffusion Tensor Imaging
Authors: Yallampalli Ragini , Wilde Elisabeth A. , Bigler Erin D. , McCauley Stephen R. , Hanten Gerri , Troyanskaya Maya , Hunter Jill V. , Chu Zili , Li Xiaoqi , Levin Harvey S.
Published: November 2010

The integrity of the fornix using diffusion tensor imaging (DTI) in adolescent participants with acute mild traumatic brain injury (mTBI) compared to a demographically matched control group was examined. Fractional anisotropy (FA) in the fornix was elevated in the mild traumatic brain injured group. Performance on the Automated Neuropsychological Assessment Metrics (ANAM) was lower in the group with mTBI. A relation was found between lower performance on cognitive tasks and higher FA. The potential role of fornix injury as a basis of memory and processing speed deficits in mTBI is discussed.
Treatment and side effect management of CTLA‐4 antibody therapy in metastatic melanoma
Authors: Kähler Katharina C. , Hauschild Axel
Published: November 2010

Immune‐modifying monoclonal antibodies may induce or enhance the natural immune response against tumor cells. The complex interaction between antigen‐presenting cells and T lymphocytes as an immune response is strongly affected by anti‐CD152 (CTLA‐4)‐antibodies. The cytotoxic T‐lymphocyte (CTLA‐4) receptor binds molecules of the B7‐family which leads to a suppression of T cells. Specific CTLA‐4 antibodies induce an unrestrained T‐cell activation. Treatment with the CTLA‐4 antibodies ipilimumab and tremelimumab has been investigated in metastatic melanoma only within clinical trials. Currently, the critical phase III trial on ipilimumab is in the final analysis process and expected to lead to approval.

CTLA‐4 antibodies belong to the most promising new molecules for the treatment of advanced melanoma. During treatment with CTLA‐4 antibodies, distinct adverse events may occur. Treating physicians must be familiar with their appropriate treatment and prophylaxis. The most frequently observed side effects are diseases such as an autoimmune colitis which is typically characterized by a mild to moderate, but occasionally also severe and persistent diarrhea. Other autoimmune‐mediated side effects like hypophysitis, hepatitis, iridocyclitis or an exacerbation of lupus nephritis have been reported in the literature. Their early recognition and treatment are mandatory to reduce the risk of sequelae for CTLA‐4‐antibod‐treated patients. Autoimmune‐mediated side effects are reported to correlate positively with treatment response. We review the mechanisms of action, provide an update on clinical trials with the two CTLA‐4‐antibodies for metastatic melanoma, and present detailed recommendations for managing the side effects of these new agents.
A Polynomial Chaos-Based Kalman Filter Approach for Parameter Estimation of Mechanical Systems
Authors: Blanchard Emmanuel D. , Sandu Adrian , Sandu Corina
Published: November 2010

Mechanical systems operate under parametric and external excitation uncertainties. The polynomial chaos approach has been shown to be more efficient than Monte Carlo for quantifying the effects of such uncertainties on the system response. Many uncertain parameters cannot be measured accurately, especially in real time applications. Information about them is obtained via parameter estimation techniques. Parameter estimation for large systems is a difficult problem, and the solution approaches are computationally expensive. This paper proposes a new computational approach for parameter estimation based on the extended Kalman filter (EKF) and the polynomial chaos theory for parameter estimation. The error covariances needed by EKF are computed from polynomial chaos expansions, and the EKF is used to update the polynomial chaos representation of the uncertain states and the uncertain parameters. The proposed method is applied to a nonlinear four degree of freedom roll plane model of a vehicle, in which an uncertain mass with an uncertain position is added on the roll bar. The main advantages of this method are an accurate representation of uncertainties via polynomial chaos, a computationally efficient update formula based on EKF, and the ability to provide a posteriori probability densities of the estimated parameters. The method is able to deal with non-Gaussian parametric uncertainties. The paper identifies and theoretically explains a possible weakness of the EKF with approximate covariances: numerical errors due to the truncation in the polynomial chaos expansions can accumulate quickly when measurements are taken at a fast sampling rate. To prevent filter divergence, we propose to lower the sampling rate and to take a smoother approach where time-distributed observations are all processed at once. We propose a parameter estimation approach that uses polynomial chaos to propagate uncertainties and estimate error covariances in the EKF framework. Parameter estimates are obtained in the form of polynomial chaos expansion, which carries information about the a posteriori probability density function. The method is illustrated on a roll plane vehicle model.
Vibration Response Modes and Severity Rating for Freight Car Appliances
Authors: Shust William , Iler Darrell
Published: November 2010

For many years, the North American Railway industry has been interested in the shock and vibration environment of freight cars. Initially this interest was related to the potential damage to cargo. More recently the interest has expanded to enhanced car and component reliability. A recent important subtopic has been the installed resonance frequencies of pneumatic equipment for air brake control valves (CVs). Perhaps the most critical accessory feature of a railcar is the braking system — a complicated assembly of pneumatic controls and air reservoirs. Millions of pneumatic brake control valves are in service every day in North America. To work properly, these devices depend on spring-loaded parts moving within very small dimensional clearances. As pneumatic controls, they are challenged to receive and repeat subtle air difference signals down the length of any train they comprise. Further, they are expected to work in all weather and operating conditions, and for several years at a time without any maintenance or inspection. At this time, the North American rail industry does not have any standards for CV design (or mounting) that accounts for vibration. The CV builders themselves have put one proposal forward. The industry is currently discussing this proposed design limit — it would require installed natural frequencies to be above a minimum value. The valves themselves have been studied at length. However an examination of the current variations in both acceptable and “suspect” railcars has not been available thus far. In this paper, resonance variations for existing attachment methods will be presented, as well as common response modes. In addition, a preliminary method for predicting the severity of vibration levels for different freight cars will be presented.
Effective Friction Control for Optimization of High Speed Rail Operations
Authors: Eadie Donald T. , Oldknow Kevin , Oka Yasushi , Hui Ron , Klauser Peter , Dick Matt
Published: November 2010

Expected growth of High Speed Rail (HSR) in North America will in many instances involve operation on existing infrastructure, shared with other traffic. This will pose many challenges, not least of which will be wheel and rail wear, and ride quality. This paper addresses how effective friction control can be employed to mitigate these factors and provide an important tool to the designers of new systems. Case studies describe successful use of train mounted solid stick LCF flange lubrication on high speed trains in East Asia and Japan. In each case, higher speed train operation has involved operation on areas of track with greater curvature than usual on dedicated high speed track. Appropriately designed LCF systems provide an inherently very high level of reliability and very low flange wear rates. Use of dry thin film lubricant technology has advantages over use of liquid lubricants (oil and grease) which can experience splash and fling off at high train speeds. Train mounted solid sticks provide greater consistency / reliability and ease of maintenance compared with wayside gauge face lubrication. Complementing practical field experience, modeling studies are presented which show the potential of high performance flange lubrication to allow for additional flexibility in designing wheel profiles for high speed rail. The ideal profile will balance vehicle stability (benefiting from lower conicity) and curving performance (benefiting from higher conicity). In a high speed train with long wheel base and high suspension stiffness operating in areas with significant curvature, finding an appropriate compromise becomes even more challenging than usual. Controlling flange wear at low rates with highly effective solid stick lubrication offers the opportunity to use wheel profiles providing lower effective conicity and therefore better ride quality, without compromising wheel life. This approach will be practical only in a scenario where a very high reliability wheel / rail lubrication system is employed.
High Speed Locomotive Development: A European Experience
Authors: Vitins Janis
Published: November 2010

Europe has a long history of high speed locomotive and power unit development. This paper focuses on these developments in Sweden, Germany, Switzerland and Spain starting from high speed locomotives for 125 mph and ending with the AVE S112 high speed power unit for 206 mph. The major technical objectives starting in the 1970’s were to increase the speed and performance, while reducing the axle load from typically 21t at 125 mph to 17t at ≥ 156 mph. Developments of the propulsion system and vehicle concepts took place in many incremental steps, constantly improving the performance of high speed services. It is shown how American high speed locomotives relate to these developments and how one can learn from the European experience going forward.
An Approach to Wind Blow-Over Risk Reduction at BNSF Railway
Authors: Shust William , Pasta Corey , Milhon Larry , Rosenberger Walter , Dumont Brian J. , Miller Jenifer L.
Published: November 2010

FRA derailment statistics between 1996 and 2009 show an average of 13 derailments each year industry-wide are attributed to extreme winds, roughly 7 of which result in vehicles blowing over and derailing. BNSF Railway has developed a hybrid process to identify critical crosswind speeds for various types of railcars to mitigate future blow-over derailment risk. The method uses computational fluid dynamics to compute the wind effects based on the car envelope. These wind effects are simplified in an empirical spreadsheet tool for various wind and train speeds, and wind heading angles. CFD analysis and reduction into the empirical spreadsheet tool have been completed for alimited set of car types. With the resulting external wind loads, vehicle dynamic simulations are used to evaluate the propensity for wheel unloading. Both VAMPIRE® and NUCARS® dynamics routines were used for various parts of this study. In all cases, the wind onset has been assumed to ramp from a zero to full wind condition which remains steady from there forward. The main paper will cover several steps within this project: aerodynamic investigations and generation of appropriate load sets, preliminary and secondary vehicle dynamic simulations, and simplified train operating guidelines proposed thus far. The paper is summarized with a discussion of how these results may be applied to further mitigate wind blow-over derailments in terms of operating rules and the operating environment. An appendix is provided which outlines the relationships between the CFD wind loads and assumed train simulation speeds.
Insulated Railway Joint Design Methodology Through Parametric Finite Element Based Modeling
Authors: Holland Chase C. , Do Thong Q. , West Robert L. , Ahmadian Mehdi
Published: November 2010

The Railroad Industry experiences multiple failures with currently used bonded insulated joint designs. These failures have encouraged an increased effort in strength and fatigue analysis for the joints. This paper presents a program initiated by Virginia Tech and Transportation Technology Center Incorporated (TTCI) to develop, analyze, and test a family of insulated joint designs featuring non-adhesive bolted connections. This program utilizes a hierarchical set of Finite Element (FE) parametric models that explore the problem’s mechanics for a family of rail joint design concepts by refining the analysis with each subsequent model. Currently, there is limited information concerning design criteria for insulated joints in the Railroad industry. Therefore, an initial task in this program is to define design criteria and representative load cases characteristic of typical life cycles for commercial freight rails. Design criteria are either proprietary to the railroad or do not appear to be published in the AREMA handbooks. However, the AREMA handbooks do define an acceptance test for the failure of rail joint. Failure criteria were derived from the AREMA rolling wheel acceptance test with some modifications to the magnitude of the loads. Using these load cases and design criteria, multiple FE models are used to identify the dominant mechanics of the bolted joint and contact problem. Each model features parametric relationships that enable rapid design changes including geometric features and mechanics. The development of hierarchical FE models facilitates the selection of a specific model that embodies the essential mechanics of the problem while maintaining a geometry that allows for parametric tradeoff studies. The design variables and baseline finite element model are used as an analysis tool developed as an Abaqus scripted template for design comparison studies. The hierarchical approach to finite element modeling with a parametric model has been applied to the development of a bolted insulated rail joint design, which has been realized in a new insulated joint prototype. The mechanics explored in the FE models can be verified using various full-scale load frame tests in a controlled environment. Tests are standardized across models using identical boundary conditions and load cases. The results obtained will be used to confirm modeling assumptions and provide necessary information for further prototype development. The prototype of the full 3-D geometry will be tested in track at TTCI for final design verification. The hierarchical parametric finite element modeling approach results in a tool that can be applied to joint design across the rail industry.
Positive Train Control and the Rail Safety Improvement Act of 2008
Authors: Hartong Mark , Goel Rajni , Wijesekera Duminda
Published: November 2010

A series of high profile rail accidents, culminating in a head on collision on September 12, 2008 between a Union Pacific freight train and a METROLINK passenger train in Chatsworth, California, provided the impetus for the passage of the Rail Safety Improvement Act (RSIA) of 2008 (Public Law 110–432). The RSIA mandated the installation of Positive Train Control Systems across the US rail system by December 31, 2015. These new statutory requirements represent one of the most significant changes in US signal and train control systems since the introduction of track circuits and Centralized Traffic Control in the 1920’s. This paper discusses the background which led to the passage of the RSIA, the new PTC requirements imposed by the law, and highlights the significant changes from existing federal safety regulations associated with voluntary PTC implementations that are being adopted by the to meet the law’s requirement.
Rolling Contact Fatigue in Passenger and Freight Railroads
Authors: Tunna John
Published: November 2010

Rolling Contact Fatigue (RCF) can occur on wheels and rails in passenger and freight railroads. It can be a significant cost driver, and, if left untreated, it may lead to derailments. Tangential wheel-rail forces, creepage and contract stress are shown to be the causes of RCF. Improved vehicle curving performance and optimized wheel and rail profiles are shown to have benefits. Methods of managing RCF are preventive rail grinding and wheel turning. Improved wheel and rail materials can also have benefits. The paper includes examples of rail and wheel RCF in both passenger and freight railroads. References are given to other papers for further reading on this subject.
Spiral Length Design
Authors: Hasan Nazmul
Published: November 2010

Most of the current formulae for spiral length use either unbalance, Eu or actual super-elevation, Ea to calculate spiral length, L as applied to light rail, commuter rail, and rapid transit. In reality, a train suffers both Eu and Ea run-off simultaneously. Super-elevation unbalance run-off produces the effect of radial acceleration and actual super-elevation run-off produces the effect of rotation. As a result due to this spiral length design should be based on both Ea and Eu. The current formulae underestimate spiral length which affects comfortable jerk rate, roll criteria, and twist rate. These formulae do not shed any light on how to proportion actual and unbalance superelevation to realize desired results. Consequently from these formulae, desirable values of Ea and Eu cannot be calculated, so it is necessary to re-evaluate the current formulae. It is mathematically established that combined effects of Ea and Eu run-off set a limit of 45mm/sec. A new formula for spiral length comes out to be: L = 0.006(Ea+Eu)V. But this formula does not reflect the effect of proportion of Ea and Eu. This gives the same length whatever be the proportion of Ea and Eu. To overcome this deficiency a second formula is derived as: L=VEa161−Eu. The article analyzed the effect of proportion of Ea and Eu on spiral length. The formulae developed in the paper satisfy both cant gradient and rotation criteria that are currently used. If these formulae are used, these criteria do not require checking. The analysis reveals the basis of cant gradient that is to be used for spiral length design. As extensions of these new formulae are developed for minimum spiral length, minimum length of circular curve, rate of twist, maximum safe speed etc. For Heavy haul operation issues of over-loading and off-loading on the twisted track is also discussed to review cant gradient for spiral length design.
Implementation of Wheel-Rail Friction Management Strategy on MRS Railroad
Authors: Jorge Cristiano , Vidon Walter , Vidon Felipe , Caldwell Rob
Published: November 2010

For several years, North American Railroads and their Research Institutions’ have been involved in implementing best-practice friction management strategies on heavy haul tracks. During 2006, MRS Railroad visited CP Rail and was impressed with the 100% effective Friction Management strategy that had been developed and implemented in CPR mountain tracks. The strong similarity of CPR’s track and train characteristics to those of MRS Railroad was also noted. By the beginning of 2007, MRS Railroad invited NRC-CSTT to bring this innovative methodology to Brazil and to rapidly develop and implement a customized strategy of 100% effective Gauge-Face lubrication and Top-of-Rail friction management. The utilization of a Brazilian contract service to ensure proper maintenance and filling of the friction management equipment, the gathering of measurement data and analysis of results ensured the success of the project. This paper will discuss the processes (installations, inspections and monitoring), technologies (equipment, devices and tools), results and benefits based on this best-practice methodology applied to the MRS Railroad over two years (2007–2008). The work was divided into five phases: selection of an optimal rail curve grease; selection of test sites and measurement of the baseline case (dry condition); measurement and management of 100% effective Gauge-Face lubrication using rail curve grease; measurement and management of 100% effective friction management using Top-of-Rail friction modifier; and the final economic analysis. This paper will also report the results of the business case analysis, quantifying the actual net savings accrued to MRS as a result of the implementation of Friction Management on test sites, and the projected savings that will occur through the expansion of this strategy to the entire MRS system. In the last 12 years, MRS’ operational reliability has significantly improved through the strategic application of innovation, technology and knowledge. Expanding this strategy to include best-practices friction management will contribute to increased safety and productivity at MRS. Production is projected to increase from over 136 million net tonnes expected in 2010 to 300 million net tonnes by 2018.
Composite Plastic Ties in MRS Heavy Haul Railroad
Authors: Rodrigues Celia
Published: November 2010

This article discusses the studies for applying synthetic – composite recycled plastic ties, along the track of the MRS heavy haul railroad. The purpose if this paper is to present the studies and results of field and laboratory tests, referring to work cycles of readings, investigations and analyses of steel and synthetic ties performance, comparing with wood ties on railway track of the MRS Logistica railroad net. MRS is a Heavy Haul Co. in Brazil that transports over one hundred and thirty million net metric tones on MRS’ network. Experimental stretches were established where readings of track deflection under train loads were taken using new technologies as laser equipment; samples from the ballast and subgrade layers were collected and taken for laboratory tests. In the case of the composite plastic ties, Brazilian supply chain, environment benefits and ties performance are presented.
The Use of Strain Attenuating Tie Pads and Its Influence on the Rail Seat Load in Heavy-Haul Railroads
Authors: Giannakos Konstantinos
Published: November 2010

In Greece, during the 1980’s, 60% of the twin-block concrete ties designed for 200 km/h, which were laid on a track with maximum operational speed of 140 km/h, presented serious cracks. The existing theories, in the French, German and American bibliographies, could not justify the appearance of these cracks since the calculated actions on the rail seat of the ties were much lower than the limit values of the regulations. This paper presents a model for the determination of the load acting on the rail seat of the ties in relation to the fluctuation of the substructure stiffness coefficient. The basic parameters influencing the estimation of the rail seat load — considering the most adverse conditions of a railway network — are investigated, and a methodology for calculating the load undertaken by each rail seat is presented. Numerical applications on twin-block and monoblock ties are presented, including the use of strain attenuating tie pads with high resilient fastenings. Finally, an application for the heavy-haul rail transport is presented, for the case of a track equipped with W24 fastening, Zw700WIC pad, rail 140RE type and concrete sleepers.
Applied High Resolution Traffic Controller Data Outcome Based Performance Measures With Gate-Down Confirmation Circuit
Authors: Brennan Thomas M. , Sturdevant James R. , Bullock Darcy M.
Published: November 2010

Track clearance green phases are used at railroad preempted intersections to provide time to clear the railroad tracks of highway vehicles before a train arrives. This paper describes preemption performance measures developed in Indiana that use high resolution, real-time traffic signal event data, and a gate-down confirmation circuit at an active railroad crossing. These performance measures are used to quantitatively assess the synchronization of the track clearance phase with the railroad gate position. Performance measure plots from over 4,000 preemption events over six months are presented. The lessons learned from the assessment of these performance plots are described along with changes made to the test site during the study period. The paper concludes with recommendations for incorporating a highway-railroad synchronization performance measure using the start of railroad active warning time as a surrogate gate-down confirmation circuit.
A Constraint-Based Scheduling Model for Optimal Train Dispatching
Authors: Rodriguez Joaqui´n , Marlie`re Gre´gory , Sobieraj Sonia
Published: November 2010

Railway networks are faced to an increase demand of new services. This situation leads to train schedules close to the maximum capacity of the infrastructure. As the extension of the infrastructure is too expensive, an alternative solution is to improve traffic management in congested areas. This task can be formulated as an optimization problem which is a joint scheduling and allocation problems. The problem is considered to be a NP-hard problem which makes it difficult to solve using exact methods for a reasonable problem size. In this paper, we compare two heuristic methods for solving the problem. The first one uses a two-phase approach to perform independently resource allocation and scheduling. The second one performs incrementally the two kind of decisions at track section level, i.e. at each step, the algorithm performs decisions of allocation of a track section or of scheduling a pair of train runs on this section.
When is High-Speed Rail Fast Enough?
Authors: Sislak Kenneth G.
Published: November 2010

The vision for high-speed rail in America includes corridors that are “emerging” as candidates for investment in passenger rail service improvements including increasing maximum authorized speeds to 90 and 110 mph. Will increasing speeds up to 110 mph be cost effective in terms of attracting new riders? This paper will explore the results of studies examining incremental capital costs and the marginal ridership and revenue increases in the Richmond – Hampton Roads passenger rail project and other current emerging high-speed rail corridors throughout the United States.
Research on Track Alignment Irregularity Prediction Models
Authors: Wang F. T. , Guo R. , Liu R. K.
Published: November 2010

Under repetitive trainloads, lateral track displacement causes alignment irregularities in ballasted track structures, which in turn leads to gradual track state deterioration. For the prediction of alignment irregularities development, the Railway Technical Research Institute (RTRI) in Japan has adopted the analytical method of track mechanics to develop an alignment irregularity prediction model which takes track strength, deformation, operational conditions and maintenance & repair into overall account. Based on the actual situation of railway lines in China, this paper sets out to examine the pattern of changes in track alignment irregularity in relation to gross passing tonnage and develop a model of local alignment irregularity degradation called MPLIPM. The model uses track waveform data generated by the track geometry car to predict track alignment irregularities of a unit section. After comparing the predicted values with the actually measured data, evaluation results verified the accuracy of this model.
Illinois High-Speed Rail Four-Quadrant Gate Reliability Assessment
Authors: Hellman Adrian , Ngamdung Tashi
Published: November 2010

The United States Department of Transportation’s (USDOT) Research and Innovative Technology Administration’s John A. Volpe National Transportation Systems Center (Volpe Center), under the direction of the USDOT Federal Railroad Administration (FRA) Office of Research and Development (ORD), conducted a reliability analysis of the four-quadrant gate/vehicle detection equipment installed on the potential high-speed rail (HSR) corridor between Chicago and St Louis. A total of 69 highway-rail grade crossings on a 121-mile (195 km) segment of the 280-mile corridor were equipped with four-quadrant gates and inductive loop vehicle detection technology. This segment, between Mazonia and Springfield Illinois, may eventually carry passenger trains at speeds up to 110 mph (177 km/h), including at many of the highway-rail grade crossings. The analysis was based on maintenance records obtained from the Union Pacific Railroad (UPRR), the owner and operator of the rail line. The results were used to assess the impact of the equipment reliability on the proposed HSR timetable. The Volpe Center study showed that the total average delay to the five scheduled daily high-speed passenger roundtrips was an estimated 10.5 minutes, or approximately one minute per train. Overall, extensive analysis of the trouble ticket data showed that the four-quadrant gate and vehicle detection equipment had a minimal direct impact on the frequency and duration of grade crossing malfunctions.
Development and Implementation of Recycled Thermoplastic RR Ties
Authors: Vijay P. V. , Hota GangaRao V. S. , Bethi Aneesh , Chada Venugopal , Qureshi Muhammad A. M.
Published: November 2010

About a billion wood cross-ties are in service in North America for safe and effective transfer of heavy freight or high-speed passenger train loads. These wood ties are facing long-term safety and serviceability issues related to ever increasing intensities and frequencies, and harsh field conditions. In addition to other applications, the Constructed Facilities Center, West Virginia University (CFC-WVU) has been investigating the use of recycled polymer composite railroad (RR) ties with discarded wood or rubber core to safely alleviate many of the problems posed by creosote treated timber ties. In this research, mechanical property characterization of recycled thermoplastics was carried out prior to manufacturing RR ties with continuous glass fiber reinforced (GFRP) polymer composite shell with recycled polymer, and wood/FRP (fiber reinforced polymer) core. GFRP Composite ties manufactured with thermoplastics and continuous glass fiber/fabric have exhibited high strength/stiffness unlike plastic ties with chopped fibers. Local cracking from spikes was found to be negligible. Half- and full-scale RR ties were subjected to static loads of 80 kips and fatigue loads up to 12.5 million cycles with a strain range of 750 micro strains (με, i.e., 750×10−6) in FRP composite shell. Spike pull-out tests were conducted on full-scale RR tie specimens. Results showed high strength/stiffness of these ties under static loads and also excellent strength retention under millions of fatigue cycles. Field installed ties exhibited maximum strain of 1070 micro-strains under actual locomotive loads moving at 15 mph.
Who Rides These Things?
Authors: Heiss Jack E.
Published: November 2010

While planners and politicians alike go about kicking the tires of various trains, and traveling abroad on fact-finding missions about HSR, the question remains whether Americans will patronize high-speed rail in sufficient number to justify the investment. A common practice is to identify an existing or abandoned rail line as the candidate route that connects population centers, identify the former stations for rehabilitation, select a technology, and then perform an investment-grade ridership study to determine whether sufficient revenues will be generated. This approach may prove sufficient in the upgrading of an existing conventional service, or re-establishing a previous service in those areas of the country with a long history of passenger rail. When approaching newer developed areas such as the Sunbelt cities, the inter-relationship of development patterns and fixed-guideway passenger services is not established. Those development patterns were influenced by the automobile, not by guideway-based transportation. A different approach is needed when history is not a guide. While the selection of the population centers to be served at the outset is appropriate and makes for a basic identification of the market to be served, it does not reveal the actual destinations that are interest to the travelers. The next step is to more thoroughly investigate travel between those points. That investigation should include surveys to determine trip purpose, identify the main attractors in the markets, the demographics of the travelers and how time is valued by the travelers. Finally, estimates must be made of the absolute numbers of those traveling. Additionally, examination of the current travel patterns through the patronage of existing services can provide clues to the market demand. The acquisition of this market information then allows the planners to design a transportation product that will appeal to the potential customers and make a determination of potential revenue. Even when certain parameters of a system are set because of geography or availability of infrastructure, market information can guide improvements to maximize market capture. This paper will examine those data that are important to a high-speed rail plan and how some system decisions directly affect the ability of the transportation product offered to satisfy the needs of the traveling public. “Build it and they will come” cannot be trusted to repay the massive investment required by high-speed rail.
Application Research on Revenue Management in China High Speed Railway
Authors: Li ChunYan , Ma MinShu , Li XiaoJun
Published: November 2010

Revenue management in the modern railway industry has been more and more applications. To achieve the desired results, the specific application environment must be considered. The features of China’s railway are discussed firstly, and then a method of seats allotment with objective to maximize the seat load factor is proposed to increase revenue. This method is adapted to multi seat classes on multi segments under the condition of fares relative fixed in China and also meet the need of opening pricing in future. The train T15 is chosen as the object for illustrative analysis, and the result indicate that the method is useful to improve the seat load factor. Additionally it is also effective to make the seats more in line with the trends of passenger flow, and reduce the probability and amount of long-distance tickets randomly cutting into short ones in the sales process.
Long-Term Behavior and Performance of Ballastless Track Superstructure on China’s Suining-Chongqing Railway Line
Authors: Lin Hong-song , Liu Xue-yi , Yan Hua , Ren Juan-Juan
Published: November 2010

This paper briefly shows the experimental ballastless track section of Suining-Chongqing railway line in southwest China, which was designed by China Railway Eryuan Engineering Group Co. Ltd (CREEC) and was put into operation in 2007. The design speed of the experimental section amounts to 200 km/h for passenger trains and 120 km/h for freight trains, which is the first railway line built with such speed in southwest of China. The long-term observations of the performance of the ballastless track superstructures were implemented in the past three years, which are introduced in details in this paper, such as the performance of reinforced concrete slab with lattice two-block sleepers, coupled or uncoupled prefabricated slab-superstructure etc. Ballastless track superstructures’ damages are summarized and classified. In addition, causes of damaged cracks on track superstructure are discussed.
Real Time Monitoring of Railway Traffic Using Fiber Bragg Grating Sensors
Authors: Filograno M. L. , Rodri´guez-Barrios A. , Gonza´lez-Herraez M. , Corredera P. , Marti´n-Lo´pez S. , Rodri´guez-Plaza M. , Andre´s-Alguacil A.
Published: November 2010

In this work we present field tests concerning the application of Fiber Bragg Grating (FBG) sensors for the monitoring of railway traffic. The test campaigns are performed on the Spanish high speed line Madrid–Barcelona, with different types of trains (S-102 TALGO–BOMBARDIER, S-103 SIEMENS-VELARO and S-120 CAF). We located the FBG sensors in the rail track at 70 km from Madrid in the country side, where the trains primarily are tested during commercial operation with maximum speeds between 250–300 km/h. The FBG sensor interrogation system used allows the simultaneous monitoring of four FBG sensors at 8000 samples/s. The different position of the FBG sensors in relation with the rail can be used with different purposes such as train identification, axle counting, speed and acceleration detection, wheel imperfections monitoring and dynamic load calculation.
Evaluating the Potential for Damaging Hydraulic Pressure in the Concrete Tie Rail Seat
Authors: Zeman John C. , Edwards J. Riley , Lange David A. , Barkan Christopher P. L.
Published: November 2010

Rail seat deterioration (RSD) is the most critical problem with concrete tie performance on North American freight railroads. Currently, the problem is not sufficiently understood to allow for effective solutions. RSD is considered to have up to five potential mechanisms, and this paper investigates one of them: hydraulic pressure cracking. A model of the effective stress in a concrete tie rail seat — considering the contributions of a uniform vertical load, a uniform lateral load, a prestressed beam on an elastic foundation, and pore pressure to the state of stress — was created to determine what surface water pressures at the rail seat could lead to damaging pore water pressures in the concrete. A laboratory test setup and procedure were devised to measure the surface water pressure in a laboratory rail seat using tie pads of differing material composition and geometry. Results show that the magnitude of the pressure generated and the rate of pressure dissipation with many load cycles depends on the pad material and surface geometry. Comparing the effective stress model and the measured surface pressures, hydraulic pressure cracking appears to be a feasible mechanism for RSD given the correct combination of dynamic rail seat loads, sufficient moisture, and a tie pad surface that develops high pressure.
Survivability of Railroad Tank Car Top Fittings in Rollover Scenario Derailments
Authors: Trent Robert S. , Prabhakaran Anand , Gonza´lez Francisco , Sharma Vinaya , Chitti Srinivas
Published: November 2010

Railroad tank car top fittings are susceptible to damage and failure in rollover derailments, which might result in release of hazardous material lading to the environment. In this paper, we propose and analyze five protective structure concepts designed to eliminate or reduce damage to these top fittings in a rollover derailment, using explicit finite element analyses incorporating nonlinear material and geometry models. Three different rollover scenarios are studied; a nominal rollover, a more severe rollover with greater impact energy, and a rollover combined with longitudinal velocity, with the tank car impacting a concrete barrier. The results from these analyses as well as plans for validation testing are presented in the paper.
Evaluating the Impacts of Passenger Rail Service: Case Study and Lessons Learned
Authors: Sperry Ben , Morgan Curtis
Published: November 2010

One common yet effective method used by planners to evaluate the impacts of mass transportation modes is an on-board survey of modal users. An abundance of research exists on this topic from the perspective of evaluating urban transit services; however, background literature on the application of on-board surveys for intercity passenger rail is limited. This paper contributes to passenger rail planning by reporting on the lessons learned during a research project which included an on-board survey of passengers on the Heartland Flyer, a passenger rail route between Oklahoma City, Oklahoma and Fort Worth, Texas. Transit on-board survey literature and insight gained from past on-board surveys of intercity rail passengers were used to guide the design of this case study. Lessons learned during the on-board data collection and quality control review process are also reported. Renewed investment in the nation’s intercity passenger rail network will likely result in the need to answer critical questions about how infrastructure funds are being distributed. To answer these critical questions, the lessons learned from this case study can be used to guide the development of future on-board surveys of intercity passenger rail routes. Potential applications include the evaluation of on-board service and amenities or data to support funding requests for state appropriations or grant programs established by the Passenger Rail Improvement and Investment Act of 2008. Measuring these impacts will play a critical role in the strength of funding applications, particularly in a policy environment with a renewed sense of accountability and transparency in the use of scarce public resources for transportation investment.
Ultrasonic Acoustic Health Monitoring of Ball Bearings Using Neural Network Pattern Classification of Power Spectral Density
Authors: Kirchner William , Southward Steve , Ahmadian Mehdi
Published: November 2010

This work presents a generic passive non-contact based acoustic health monitoring approach using ultrasonic acoustic emissions (UAE) to facilitate classification of bearing health via neural networks. This generic approach is applied to classifying the operating condition of conventional ball bearings. The acoustic emission signals used in this study are in the ultrasonic range (20–120 kHz), which is significantly higher than the majority of the research in this area thus far. A direct benefit of working in this frequency range is the inherent directionality of microphones capable of measurement in this range, which becomes particularly useful when operating in environments with low signal-to-noise ratios that are common in the rail industry. Using the UAE power spectrum signature, it is possible to pose the health monitoring problem as a multi-class classification problem, and make use of a multi-layer artificial neural network (ANN) to classify the UAE signature. One major problem limiting the usefulness of ANN’s for failure classification is the need for large quantities of training data. This becomes a particularly important issue when considering applications involving higher value components such as the turbo mechanisms and traction motors on diesel locomotives. Artificial training data, based on the statistical properties of a significantly smaller experimental data set is created to train the artificial neural network. The combination of the artificial training methods and ultrasonic frequency range being used results in an approach generic enough to suggest that this particular method is applicable to a variety of systems and components where persistent UAE exist.
A Study of a Railway Traffic Demand Forecasting Model Based on Influencing Factor Analysis
Authors: Ma M. S. , Liu J. , Li C. Y. , Ma Y. X.
Published: November 2010

This paper introduced a model for the railway traffic demand prediction based on the analysis of the influencing factors over short-term passenger flow. The proposed prediction includes two parts, one for the relatively stable trend, named the basic flow forecasting, and the other for the fluctuations induced by short-term factors, named induced flow forecasting. The prediction model of the overall passenger volume utilizes the summation of the two parts. The experiments with real data demonstrate that the proposed model is effective in improving the accuracy of the prediction.
Impact of Automated Inspection Technology on Unit Train Performance
Authors: Schlake Bryan W. , Barkan Christopher P. L. , Edwards J. Riley
Published: November 2010

Automated wayside inspection systems have been developed to monitor rolling stock condition and facilitate predictive maintenance strategies. Improving the effectiveness of railcar condition monitoring has the potential for significant cost savings as a result of reduced derailments and in-service failures. This paper presents an economic analysis of the costs associated with train accidents and mainline delay due to defective railcar components. We consider track and equipment damages as well as train delay costs. We use dispatch simulation software to determine the impact of in-service failures on mainline capacity at varying traffic levels. This analysis provides a basis for the comparison of current railcar inspection practices with new integrated practices incorporating automated inspection systems.
Freight Demand Forecast for a Proposed Railway in Canada With New Approach to Freight Rail Assignment
Authors: Boozarjomehri Elham , Lovegrove Gordon R.
Published: November 2010

This research examined the freight demand forecast for a new short railway linking the Okanagan Valley in southern British Columbia to American railways in the South (Orville), and to Canadian railways in the North (Kamloops). An Origin-Destination (O-D) table including local, domestic and international demands for the Okanagan freight rail was developed based on available surveys and observed truck freight data. In the absence of data to derive utility functions, the current mode share for each commodity in the base year as well as current elasticities between truck and rail was used to forecast the mode share in the future year. Rail assignment techniques are among the forgotten problems of freight demand forecasting due to their complexities, including: 1) written and unwritten practices of the rail industry, and 2) cost functions that are classically employed in truck or auto assignments. In this study, a comprehensive review was conducted on the rail freight demand assignment techniques. A new assignment procedure was introduced by combining the available mathematical choice models and new initiatives of the Canadian government toward rail industry. Finally, the predicted share of freight rail was assigned to the rail network using three methods, which provided three independent freight demand forecasts. The mid-range forecast was selected as the freight demand for the Okanagan Valley while two others (low/high) were used for sensitivity analysis.