scholarly journals A Sensitivity Analysis of Train Speed and its Effect on Railway Capacity

2014 ◽  
Vol 1061-1062 ◽  
pp. 1208-1212
Author(s):  
Bayan Bevrani ◽  
Robert Burdett ◽  
Prasad K.D.V. Yarlagadda
Keyword(s):  
Sensitivity Analysis ◽  
Cost Effective ◽  
Railway Network ◽  
Capacity Model ◽  
The Future ◽  
Railway System ◽  
Train Speed ◽  
The Absolute ◽  
Railway Capacity

Increasing train speeds is conceptually a simple and straight forward method to expand railway capacity, for example in comparison to other more extensive and elaborate alternatives. In this article an analytical capacity model has been investigated as a means of performing a sensitivity analysis of train speeds. The results of this sensitivity analysis can help improve the operation of this railway system and to help it cope with additional demands in the future. To test our approach a case study of the Rah Ahane Iran (RAI) national railway network has been selected. The absolute capacity levels for this railway network have been determined and the analysis shows that increasing trains speeds may not be entirely cost effective in all circumstances.

scholarly journals Experimental Strain Measurement Approach Using Fiber Bragg Grating Sensors for Monitoring of Railway Switches and Crossings

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3639
Author(s):  
Abdelfateh Kerrouche ◽  
Taoufik Najeh ◽  
Pablo Jaen-Sola
Keyword(s):  
Fiber Bragg Grating ◽  
Experimental Tests ◽  
Cost Effective ◽  
Measuring Method ◽  
Bragg Grating ◽  
Railway Network ◽  
System Failures ◽  
Railway Infrastructure ◽  
Train Speed ◽  
And Control

Railway infrastructure plays a major role in providing the most cost-effective way to transport freight and passengers. The increase in train speed, traffic growth, heavier axles, and harsh environments make railway assets susceptible to degradation and failure. Railway switches and crossings (S&C) are a key element in any railway network, providing flexible traffic for trains to switch between tracks (through or turnout direction). S&C systems have complex structures, with many components, such as crossing parts, frogs, switchblades, and point machines. Many technologies (e.g., electrical, mechanical, and electronic devices) are used to operate and control S&C. These S&C systems are subject to failures and malfunctions that can cause delays, traffic disruptions, and even deadly accidents. Suitable field-based monitoring techniques to deal with fault detection in railway S&C systems are sought after. Wear is the major cause of S&C system failures. A novel measuring method to monitor excessive wear on the frog, as part of S&C, based on fiber Bragg grating (FBG) optical fiber sensors, is discussed in this paper. The developed solution is based on FBG sensors measuring the strain profile of the frog of S&C to determine wear size. A numerical model of a 3D prototype was developed through the finite element method, to define loading testing conditions, as well as for comparison with experimental tests. The sensors were examined under periodic and controlled loading tests. Results of this pilot study, based on simulation and laboratory tests, have shown a correlation for the static load. It was shown that the results of the experimental and the numerical studies were in good agreement.

scholarly journals A CASE STUDY OF THE IRANIAN NATIONAL RAILWAY AND ITS ABSOLUTE CAPACITY EXPANSION USING ANALYTICAL MODELS

Transport ◽  
2015 ◽  
Vol 32 (4) ◽  
pp. 398-414 ◽  
Author(s):  
Bayan Bevrani ◽  
Robert L. Burdett ◽  
Prasad K. D. V Yarlagadda
Keyword(s):  
Sensitivity Analysis ◽  
Traffic Flow ◽  
Upper Bounds ◽  
Analytical Models ◽  
Optimization Approach ◽  
Lower And Upper Bounds ◽  
Train Services ◽  
Railway Capacity ◽  
Capacity Determination

Identifying railway capacity is an important task that can identify ‘in principal’ whether the network can handle an intended traffic flow, and whether there is any free capacity left for additional train services. Capacity determination techniques can also be used to identify how best to improve an existing network, and at least cost. In this article, an optimization approach has been applied to a case study of the Iran national railway, in order to identify its current capacity and to optimally expand it given a variety of technical conditions. This railway is very important in Iran and will be upgraded extensively in the coming years. Hence, the conclusions in this article may help in that endeavor. A sensitivity analysis is recommended to evaluate a wider range of possible scenarios. Hence, more useful lower and upper bounds can be provided for the performance of the system.

scholarly journals An Integrated Methodology for the Multi-Objective Optimization of Port Railway Capacity: The Case Study of the Port of Trieste

2021 ◽  
Vol 13 (19) ◽  
pp. 10490
Author(s):  
Caterina Caramuta ◽  
Giovanni Longo ◽  
Teresa Montrone ◽  
Carlo Poloni
Keyword(s):  
Railway Network ◽  
Operational Conditions ◽  
Environmentally Sustainable ◽  
Integrated Methodology ◽  
Traffic Volumes ◽  
Residual Capacity ◽  
Railway Capacity ◽  
Administrative Tasks

The relevant pressure exerted on ports following the advent of globalization and containerization has contributed to transform the role of such intermodal transport facilities, increasing their complexity with reference to both performed activities and involved actors. The potential of solid hinterland connections in enhancing port competitiveness has sustained the larger embracement of the railway mode, which has proved to be a financially and environmentally sustainable solution, especially on long hauls. However, the limited residual capacity currently characterizing several railway network and nodes may threaten the accommodation of additional future traffic volumes and, thus, it requires the adoption of a coordinated strategy to more efficiently manage existing railway infrastructures, other than the realization of some new ones. In this regard, an integrated methodology has been developed to specifically model, simulate and optimize port railway processes, as part of a more complex system, imposing the maximization of capacity with the concurrent minimization of used shunting locomotives, to varying of infrastructural and operational conditions. This combination of techniques has been applied to the case study of the Port of Trieste, Italy, showing the greater influence of tracks availability over changes in the operational conditions, in terms of a shorter duration of specific administrative tasks and the employment of more shunting locomotives.

scholarly journals Subcategorizing the Expected Value of Perfect Implementation to Identify When and Where to Invest in Implementation Initiatives

2020 ◽  
Vol 40 (3) ◽  
pp. 327-338
Author(s):  
Kasper Johannesen ◽  
Magnus Janzon ◽  
Tomas Jernberg ◽  
Martin Henriksson
Keyword(s):  
Health Care ◽  
Health Care Systems ◽  
Cost Effective ◽  
Quality Adjusted Life Year ◽  
Expected Value ◽  
Net Benefit ◽  
Relative Value ◽  
Care Systems ◽  
The Absolute

Purpose. Clinical practice variations and low implementation of effective and cost-effective health care technologies are a key challenge for health care systems and may lead to suboptimal treatment and health loss for patients. The purpose of this work was to subcategorize the expected value of perfect implementation (EVPIM) to enable estimation of the absolute and relative value of eliminating slow, low, and delayed implementation. Methods. Building on the EVPIM framework, this work defines EVPIM subcategories to estimate the expected value of eliminating slow, low, or delayed implementation. The work also shows how information on regional implementation patterns can be used to estimate the value of eliminating regional implementation variation. The application of this subcategorization is illustrated by a case study of the implementation of an antiplatelet therapy for the secondary prevention after myocardial infarction in Sweden. Incremental net benefit (INB) estimates are based on published cost-effectiveness assessments and a threshold of SEK 250,000 (£22,300) per quality-adjusted life year (QALY). Results. In the case study, slow, low, and delayed implementation was estimated to represent 22%, 34%, and 44% of the total population EVPIM (2941 QALYs or SEK 735 million), respectively. The value of eliminating implementation variation across health care regions was estimated to 39% of total EVPIM (1138 QALYs). Conclusion. Subcategorizing EVPIM estimates the absolute and relative value of eliminating different parts of suboptimal implementation. By doing so, this approach could help decision makers to identify which parts of suboptimal implementation are contributing most to total EVPIM and provide the basis for assessing the cost and benefit of implementation activities that may address these in future implementation of health care interventions.

scholarly journals Geometry deviation effects of railway catenaries on pantograph–catenary interaction: a case study in Norwegian Railway System

2021 ◽  
Author(s):  
Yang Song ◽  
Tengjiao Jiang ◽  
Petter Nåvik ◽  
Anders Rønnquist
Keyword(s):  
Contact Force ◽  
High Frequency ◽  
Loss Rate ◽  
Lumped Mass ◽  
Railway Network ◽  
The Monte Carlo Method ◽  
Spectrum Density ◽  
Railway System ◽  
Geometry Deviation

AbstractThis paper presents a non-contact measurement of the realistic catenary geometry deviation in the Norwegian railway network through a laser rangefinder. The random geometry deviation is included in the catenary model to investigate its effect on the pantograph–catenary interaction. The dispersion of the longitudinal deviation is assumed to follow a Gaussian distribution. A power spectrum density represents the vertical deviation in the contact wire. Based on the Monte Carlo method, several geometry deviation samples are generated and included in the catenary model. A lumped mass pantograph with flexible collectors is employed to reproduce the high-frequency behaviours. The stochastic analysis results indicate that the catenary geometry deviation causes a significant dispersion of the pantograph–catenary interaction response. The contact force standard deviations measured by the inspection vehicle are within the scope of the simulation results. A critical cut-off frequency that covers 1/16 of the dropper interval is suggested to fully describe the effect of the catenary geometry deviation on the contact force. The statistical minimum contact force is recommended to be modified according to the tolerant contact loss rate at high frequency. An unpleasant interaction performance of the pantograph–catenary can be expected at the catenary top speed when the random catenary geometry deviation is included.

scholarly journals Application of the reason model within risk management on railway crossings – a case study

2020 ◽  
Vol 109 ◽  
pp. 129-140
Author(s):  
Eva NEDELIAKOVA ◽  
Lenka LIZBETINOVA ◽  
Renata STASIAK-BETLEJEWSKA ◽  
Adrian SPERKA
Keyword(s):  
Risk Management ◽  
Monitoring And Evaluation ◽  
Rail Transport ◽  
Material Damage ◽  
Railway Network ◽  
Worst Case ◽  
The Future

Despite constant efforts to improve safety in the railway environment, various accidents and incidents happen, resulting in material damage and in the worst case, loss of human lives. This article emphasises the need for proper identification of risks, their constant monitoring, and evaluation of all causes that arise at railway crossings. Furthermore, this paper aims to apply the Reason model to the problems of railway crossings within the case study on the railway network in Slovakia. The timeliness of the problem lies in the possibility of preventing such issues in the operation of rail transport using this model. Prevention is an effective way of averting the serious consequences of accidents in the future.

7.2.1 UK Railway System Reliability - Modelling the Future - a Case Study

2012 ◽  
Vol 22 (1) ◽  
pp. 861-878
Author(s):  
Nigel Best ◽  
Bradley Hyland ◽  
Suzanne Waters
Keyword(s):  
System Reliability ◽  
Reliability Modelling ◽  
The Future ◽  
Railway System

scholarly journals Heating systems through the lens of the boiler: Detailed case studies to inform current and future heating system design

2019 ◽  
Vol 41 (3) ◽  
pp. 332-342
Author(s):  
George Bennett
Keyword(s):  
Energy Demand ◽  
Cost Effective ◽  
Heating System ◽  
Heat Pumps ◽  
Assessment Procedure ◽  
Study Analysis ◽  
Heating Systems ◽  
Case Study Analysis ◽  
The Future

Boilers in hydronic heating systems are the norm in the UK. Through case study analysis, covering four houses with gas central heating systems for over one year and utilising novel monitoring of the on-board diagnostic data of the boilers, performance issues were identified in this mature technology. ON/OFF cycling behaviour and oversizing were prevalent with boilers consistently unable to modulate low enough to match the building space heating demand. Cycling behaviour resulted, known to be detrimental to efficiency, with the majority of boiler operations lasting less than 10 min. Targeted case study analysis of incumbent technologies, such as boilers, utilising the latest in data collection techniques and connected appliances provides a cost effective insight to broader issues. Implications for domestic energy demand range from incremental improvements in boiler system efficiency by addressing cycling to the updating of building energy assessment models (e.g. Standard Assessment Procedure) to reflect and reward the benefits of good installation practices. An improved understanding of boiler operation may support improved product design and installation practices and are beneficial to the next generation of domestic heat, such as heat pumps. By undertaking continued in situ analysis of the incumbent technology, a more thorough foundation for the future can be ascertained. Fundamental issues of oversizing and detrimental cycling behaviour are persisting in the industry. Practical steps can be taken immediately to avoid oversizing of boilers. Building an awareness of performance penalties associated with poorly planned heating installations will have added benefit for more dynamically sensitive technologies in the future, such as heat pumps.

Gendered differences in emigration and mobility perspectives among European researchers working abroad

2014 ◽  
Vol 7 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Elisabeth Scheibelhofer
Keyword(s):  
United States ◽  
Qualitative Research ◽  
Qualitative Study ◽  
Social Relations ◽  
The United States ◽  
Research Strategy ◽  
The Future ◽  
Highly Skilled

This paper focuses on gendered mobilities of highly skilled researchers working abroad. It is based on an empirical qualitative study that explored the mobility aspirations of Austrian scientists who were working in the United States at the time they were interviewed. Supported by a case study, the paper demonstrates how a qualitative research strategy including graphic drawings sketched by the interviewed persons can help us gain a better understanding of the gendered importance of social relations for the future mobility aspirations of scientists working abroad.

scholarly journals Incentive Function of Audit Opinion for the Increase of Regional Operational Expenditure and Own-Source Revenues Through Sensitivity Analysis in Indonesia

2020 ◽  
Vol 11 (1) ◽  
pp. 20
Author(s):  
Muhammad Ikbal Abdullah ◽  
Andi Chairil Furqan ◽  
Nina Yusnita Yamin ◽  
Fahri Eka Oktora
Keyword(s):  
Sensitivity Analysis ◽  
Significant Influence ◽  
Provincial Government ◽  
Sensitivity Testing ◽  
Audit Opinion ◽  
Absolute Value ◽  
Operating Expenditure ◽  
The Absolute ◽  
Operational Expenditure

This study aims to analyze the sensitivity testing using measurements of realization of regional own-source revenues and operating expenditure and to analyze the extent of the effect of sample differences between Java and non-Java provinces by using samples outside of Java. By using sensitivity analysis, the results found the influence of audit opinion on the performance of the provincial government mediated by the realization of regional operating expenditure. More specifically, when using the measurement of the absolute value of the realization of regional operating expenditure it was found that there was a direct positive and significant influence of audit opinion on the performance of the Provincial Government. However, no significant effect of audit opinion was found on the realization value of regional operating expenditure and the effect of the realization value of regional operating expenditure on the performance of the Provincial Government. This result implies that an increase in audit opinion will be more likely to be used as an incentive for the Provincial Government to increase the realization of regional operating expenditure.

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