scholarly journals Optimization Model for Rail Line Crossover Design Considering the Cost of Delay

Author(s):  
Willem Trommelen ◽  
Konstantinos Gkiotsalitis ◽  
Eric C. van Berkum

In this study, we introduce a method to optimally select the crossover locations of an independent rail line from a set of possible crossover locations considering a fixed number of crossovers that must be used in the design. This optimal selection aims to minimize the cost of passenger delay. Previous research showed that including passenger delay in the decision of rail design choices could be beneficial from economic and societal perspectives. However, those studies were only able to evaluate a few alternatives, because the degraded schedules had to be determined manually. In this research, we introduced an integer nonlinear model to find the best crossover design. We further developed an algorithm to evaluate a set of crossovers and determine the cost of delays for all segments on a rail line given a set of potential disruptions. The monetized cost of passenger delays was used to analyze the tradeoff between the unreliability costs emerging from the delay of passengers in the case of disruptions, and the total number of required crossovers. Our model was applied on a light rail line in Bergen (Norway) resulting in 10% reduction in relation to passenger delays without increasing the number of crossovers; thus, ensuring that there were no additional costs.

Author(s):  
Edson L. Tennyson

In 1946 St. Louis Public Service Company, Missouri, the eighth largest transit system in the United States, was a highly respected metropolitan operation. In 1993 the St. Louis transit system was no longer among the 30 largest systems. The precipitous decline paralleled a 61% decline in the city of St. Louis population, offset by only modest suburban population growth. In an effort to restore transit viability to the St. Louis metropolitan area, an 18-mi light rail transit line was inaugurated in 1993. Using abandoned railroad facilities, including a downtown tunnel and Mississippi River bridge, the new light rail line connected Lambert Airport in Missouri with East St. Louis, Illinois. The results were immediate and positive. Patronage exceeded comfortable car capacity. More cars were acquired. Voters in Illinois and Missouri approved funding to expand light rail 17 mi into Illinois and 8 mi into suburban Missouri. Transit use increased 40%. Light rail carried 49% of the region's transit passenger miles in only 25% of the area. The cost of service slowed its inexorable rise as light rail moved people for 25 cents per passenger mile, down from 51 cents by bus in 1993. With fewer trunk lines and more feeder routes, bus service costs increased to 80 cents per passenger mile. Casualties declined significantly. St. Louis again has a functional transit system.


2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Li Wang ◽  
Yong Qin ◽  
Jie Xu ◽  
Limin Jia

A fuzzy optimization model based on improved symmetric tolerance approach is introduced, which allows for rescheduling high-speed railway timetable under unexpected interferences. The model nests different parameters of the soft constraints with uncertainty margin to describe their importance to the optimization purpose and treats the objective in the same manner. Thus a new optimal instrument is expected to achieve a new timetable subject to little slack of constraints. The section between Nanjing and Shanghai, which is the busiest, of Beijing-Shanghai high-speed rail line in China is used as the simulated measurement. The fuzzy optimization model provides an accurate approximation on train running time and headway time, and hence the results suggest that the number of seriously impacted trains and total delay time can be reduced significantly subject to little cost and risk.


2013 ◽  
Vol 772 ◽  
pp. 705-710
Author(s):  
Li Wei Ju ◽  
Zhong Fu Tan ◽  
He Yin ◽  
Zhi Hong Chen

In order to be able to absorb the abandoned wind, increasing wind-connect amount, the paper study the way of wind power, thermal power joint run and puts forward wind power, thermal power joint run optimization model based on the energy-saving generation dispatching way under the environment of TOU price and the target of minimizing the cost of coal-fired cost, unit commitment and pollution emissions. The numerical example finds, the TOU price can realize the goal of peak load shifting, increasing the electricity demand in the low load and reducing electricity demand in the peak load. The model can increase the amount of wind-connect grid, absorb the abandoned wind, reduce the use of coal-fired units under the environment, increase the average electricity sales price and profit of Power Company. Therefore, the model has significant economical environmental benefits


BMJ Open ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. e018729 ◽  
Author(s):  
Francesca Solmi ◽  
Mariya Melnychuk ◽  
Stephen Morris

ObjectiveIn the UK, families of disabled children are entitled to receive disability benefits to help meet costs associated with caring for their child. Evidence of actual costs incurred is scant, especially for mental health disability. In this study, we aimed to quantify the cost of mental and physical health disability in childhood and adolescence to families in the UK using the concept of compensating variation (CV).DesignRepeated cross-sectional survey.SettingThe UK general populationParticipants85 212 children drawn from 8 waves of the Family Resources Survey.OutcomesUsing propensity score matching we matched families with a disabled child to similar families without a disabled child and calculated the extra income the former require to achieve the same living standards as the latter, that is, their CV. We calculated the additional costs specifically associated with several definitions of mental health and physical health disability.ResultsFamilies of a child with any mental health disability, regardless of the presence of physical health comorbidity, needed an additional £49.31 (95% CI: 21.95 to 76.67) and, for more severe disabilities, an additional £57.56 (95% CI: 17.69 to 97.44) per week to achieve the same living standards of families without a disabled child. This difference was greater for more deprived families, who needed between £59.28 (95% CI: 41.38 to 77.18) and £81.26 (95% CI: 53.35 to 109.38) more per week depending on the extent of mental health disability. Families of children with physical health disabilities, with or without mental health disabilities, required an additional £35.86 (95% CI: 13.77 to 57.96) per week, with economically deprived families requiring an extra £42.18 (95% CI: 26.38 to 57.97) per week.ConclusionsMental and physical health disabilities among children and adolescents were associated with high additional costs for the family, especially for those from deprived economic backgrounds. Means testing could help achieve a more equitable redistribution of disability benefit.


Author(s):  
Benito Mignacca ◽  
Giorgio Locatelli ◽  
Mahmoud Alaassar ◽  
Diletta Colette Invernizzi

The key characteristics of small modular reactors (SMRs), as their name emphasized, are their size and modularity. Since SMRs are a family of novel reactor designs, there is a gap of empirical knowledge about the cost/benefit analysis of modularization. Conversely, in other sectors (e.g. Oil & Gas) the empirical experience on modularization is much greater. This paper provides a structured knowledge transfer from the general literature (i.e. other major infrastructure) and the Oil & Gas sector to the nuclear power plant construction world. Indeed, in the project management literature, a number of references discuss the costs and benefits determined by the transition from the stick-built construction to modularization, and the main benefits presented in the literature are the reduction of the construction cost and the schedule compression. Additional costs might arise from an increased management hurdle and higher transportation expenses. The paper firstly provides a structured literature review of the benefits and costs of modularization divided into qualitative and quantitative references. In the second part, the paper presents the results of series of interviews with Oil & Gas project managers about the value of modularization in this sector.


2020 ◽  
Vol 2019 (1) ◽  
Author(s):  
Tessalonika Natalia Djie ◽  
Sumarno Sumarno

ABSTRAKLight Rail Transit (LRT) kini menjadi salah satu sarana transportasi darat yang sedang direncanakan untuk memenuhi kebutuhan transportasi pada suatu kota yang memiliki tingkat kepadatan penduduk yang tinggi. Di wilayah Bandung Raya telah ada rencana jalur LRT yang disusun oleh Dinas Perhubungan Provinsi Jawa Barat yang terdiri atas delapan koridor. Pada penelitian ini dilakukan evaluasi teknis rencana jalur LRT khususnya pada koridor-1 (Leuwi Panjang–Jatinangor) dan koridor-4 (Leuwi Panjang– Babakan Siliwangi). Tujuan dari penelitian ini adalah mengevaluasi tingkat kesesuaiannya dengan persyaratan teknis jalur kereta api, khususnya terhadap aspek geometrik yaitu kelandaian dan kelengkungan. Evaluasi dilakukan dengan melakukan analisis geometrik pada rencana jalur LRT dengan persyaratan teknis jalur kereta api terhadap lima kelas jalan rel. Berdasarkan hasil analisis diketahui bahwa pada koridor-1 sudah memenuhi persyaratan kelandaian dan lengkung horizontal untuk semua kelas, sedangkan koridor-4 belum memenuhi persyaratan tersebut.Kata Kunci: Light Rail Transit (LRT), kelandaian, lengkung horizontalABSTRACTLight Rail Transit (LRT) now become one of transportation means to fullfil the need of transportation in one of regions which is having high population. In Bandung Raya region, there were plans of LRT line which is arranged by Dinas Perhubungan West Java Province which consist of eight coridors. This research has done the technical evaluation for planning the LRT especially on corridor-1 (Leuwi Panjang- Jatinangor) and corridor-4 (Leuwi Panjang-Babakan Siliwangi). The aim of this reasearch is to evaluate the appropriateness levels with the rules and regulations of train technical lines, especially on the aspec of geometric including slope and horizontal curve. The evaluation is done by doing geometric analysis in the plan of LRT line with rules and regulations of train technical line toward five classes of rail line. Based on the result of analysis, it can be revealed that corridor-1 has been fullfil the rules and regulations of slope and horizontal curve for every classes, while corridor-4 do not fullfil the rules and regulations yet.Keywords: Light Rail Transit (LRT), slope, horizontal curve


Author(s):  
A. Krasheninin

Modern vehicles operated on the railways of Ukraine have almost exhausted or exceeded their resource. The overuse of financial and material resources for their maintenance continues. The standard service life of vehicles was calculated on stable economic conditions of use of vehicles and their timely updating in process of aging. The service life of modern vehicles is determined by the influence of many factors, the disregard of which can lead to significant costs, even in compliance with the standard service life. For railway transport, these factors need modern clarification, as in operation their service life often exceeds the standard or, as for intermodal transport, the service life does not have a strict justification. Accordingly, the article analyzes the issues of assessing the impact on the service life of vehicles of the components of the cost of its maintenance and average daily mileage. It is shown that, firstly, the definition of the service life of vehicles must be linked to the cost of vehicle development, its creation, testing and production, the cost of operation and storage, as well as additional costs, and secondly , with the optimal average daily mileage, at which all the costs are minimal.


2020 ◽  
Author(s):  
Godwin D Giebel

BACKGROUND With an estimated prevalence of around 3% and an about 2.5-fold increased risk of stroke, atrial fibrillation (AF) is a serious threat for patients and a high economic burden for health care systems all over the world. Patients with AF could benefit from screening through mobile health (mHealth) devices. Thus, an early diagnosis is possible with mHealth devices, and the risk for stroke can be markedly reduced by using anticoagulation therapy. OBJECTIVE The aim of this work was to assess the cost-effectiveness of algorithm-based screening for AF with the aid of photoplethysmography wrist-worn mHealth devices. Even if prevented strokes and prevented deaths from stroke are the most relevant patient outcomes, direct costs were defined as the primary outcome. METHODS A Monte Carlo simulation was conducted based on a developed state-transition model; 30,000 patients for each CHA<sub>2</sub>DS<sub>2</sub>-VASc (Congestive heart failure, Hypertension, Age≥75 years, Diabetes mellitus, Stroke, Vascular disease, Age 65-74 years, Sex category [female]) score from 1 to 9 were simulated. The first simulation served to estimate the economic burden of AF without the use of mHealth devices. The second simulation served to simulate the economic burden of AF with the use of mHealth devices. Afterwards, the groups were compared in terms of costs, prevented strokes, and deaths from strokes. RESULTS The CHA<sub>2</sub>DS<sub>2</sub>-VASc score as well as the electrocardiography (ECG) confirmation rate had the biggest impact on costs as well as number of strokes. The higher the risk score, the lower were the costs per prevented stroke. Higher ECG confirmation rates intensified this effect. The effect was not seen in groups with lower risk scores. Over 10 years, the use of mHealth (assuming a 75% ECG confirmation rate) resulted in additional costs (€1=US $1.12) of €441, €567, €536, €520, €606, €625, €623, €692, and €847 per patient for a CHA<sub>2</sub>DS<sub>2</sub>-VASc score of 1 to 9, respectively. The number of prevented strokes tended to be higher in groups with high risk for stroke. Higher ECG confirmation rates led to higher numbers of prevented strokes. The use of mHealth (assuming a 75% ECG confirmation rate) resulted in 25 (7), –68 (–54), 98 (–5), 266 (182), 346 (271), 642 (440), 722 (599), 1111 (815), and 1116 (928) prevented strokes (fatal) for CHA<sub>2</sub>DS<sub>2</sub>-VASc score of 1 to 9, respectively. Higher device accuracy in terms of sensitivity led to even more prevented fatal strokes. CONCLUSIONS The use of mHealth devices to screen for AF leads to increased costs but also a reduction in the incidence of stroke. In particular, in patients with high CHA<sub>2</sub>DS<sub>2</sub>-VASc scores, the risk for stroke and death from stroke can be markedly reduced.


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