Modeling the development of rail corrugation to schedule a more economical rail grinding

2019 ◽  
Vol 234 (4) ◽  
pp. 370-380 ◽  
Author(s):  
Hirofumi Tanaka ◽  
Masashi Miwa
Keyword(s):  
Surface Roughness ◽  
Growth Curves ◽  
Minimum Cost ◽  
Maintenance Cost ◽  
Rail Corrugation ◽  
Maintenance Schedule ◽  
Rail Grinding ◽  
Noise Vibration ◽  
Maintenance Schedules ◽  
The Cost

Rail corrugation should be managed appropriately, as it causes noise, vibration, and degradation of track components and materials. Generally, rail corrugation is managed with the removal of rail surface roughness by rail grinding. However, in many cases, rail corrugation will reoccur after the rail is ground, thereby making the management of the phenomenon difficult for railway operators. For the proper management of rail corrugation, it is necessary to understand the development of rail corrugation and model it mathematically. However, this effort has not been made in previous studies. This paper investigates an efficient method for scheduling a regular grinding maintenance to manage rail corrugation. Using regularly measured data about rail surface roughness on a commercial line, a mathematical model was developed to estimate the growth of rail corrugation. This model was utilized to estimate the effects of the remaining roughness after rail grinding on the maintenance cost and to optimize the maintenance schedule. First, it was confirmed that the development of rail surface roughness of rail corrugation can be expressed in three phases and can be modeled by fitting the functions of growth curves to measurements of rail surface roughness recorded over a long period. Next, the rail grinding strategy was examined by applying this model to realize both effective and economical strategies for the maintenance of rail corrugation. This study confirmed that maintenance costs can be reduced by rail grinding that removes almost all of rail corrugation. In the case of ballasted tracks, it has been found that the optimal grinding schedule can reduce the cost of rail grinding as well as the cost of tamping. These findings can be applied by railway operators tasked with managing maintenance schedules for railway lines at a minimum cost.

A preventive, opportunistic maintenance strategy for the catenary system of high-speed railways based on reliability

2019 ◽  
Vol 234 (10) ◽  
pp. 1149-1155
Author(s):  
Hongbo Cheng ◽  
Yufan Cao ◽  
Jiaxin Wang ◽  
Wei Zhang ◽  
Han Zeng
Keyword(s):  
High Speed ◽  
Maintenance Cost ◽  
Opportunistic Maintenance ◽  
Maintenance Schedule ◽  
Maintenance Time ◽  
Study Results ◽  
Railway System ◽  
Vital Component ◽  
Catenary System ◽  
Maintenance Schedules

The catenary is a vital component of the electrified railway system. It consists of many parts which are interrelated; the maintenance schedule of the catenary system should consider the influence of the interrelationship. In this study, a preventive, opportunistic maintenance method is proposed to schedule the maintenance process of the catenary system. First, the reliability of the key parts of the catenary is modeled using Weibull distribution. Second, a reliability margin is proposed to expand the maintenance time from point to interval, and the reliability margin is optimized to minimize the maintenance cost. Then, a preventive opportunistic maintenance schedule can be arranged on the basis of the optimal reliability margin. Case study results verify that the proposed preventive opportunistic maintenance method can reduce the number of maintenance schedules and can effectively save the maintenance cost.

DESIGN CONSIDERATIONS FOR MAINTENANCE: FACILITY MANAGERS’ PERSPECTIVE

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Armin Jalali Sohi ◽  
David Arditi ◽  
Afshin Jalali Sohi
Keyword(s):  
Life Cycle ◽  
Construction Projects ◽  
Facility Management ◽  
Design Stage ◽  
Maintenance Cost ◽  
Design Phase ◽  
Maintenance Schedule ◽  
The Us ◽  
Design Deficiencies ◽  
The Cost

Maintainability is one of the considerations designers take into account in the design stage of building construction projects. In other words, maintainability is a design consideration that may improve ease of maintenance during operation. The designer is expected to include maintenance knowledge and experience into the design, including planning for specific tools to facilitate implementation. Maintainability issues appear during the occupancy stage and have a direct impact on the cost of owning and operating a facility. Annual operation and maintenance expenses during the life cycle of a building could amount to many times the initial construction cost. Design deficiencies constitute one of the main reasons for high annual maintenance cost. Facility management involves activities to maintain and operate a constructed facility. It is essential to evaluate facility managers’ perspective on how maintainability characteristics should be considered at design phase of facilities. A survey of 168 facility managers in the mid-west region of the US is uncovered that (1) maintainability should be top priority in design, especially for mechanical systems, (2) deferred maintenance should be avoided because it increases costs over the life-cycle of buildings, and (3) constructed facilities should be handed over with a maintenance schedule provided by the designer. Paying special attention to maintainability in the design phase is expected to help reducing the cost of operation.

Cost Effective Maintenance of Wind Turbines Using Finite State Markov Model

2015 ◽  
Vol 799-800 ◽  
pp. 1422-1426
Author(s):  
Lahcene Boukelkoul
Keyword(s):  
Markov Model ◽  
Optimal Solution ◽  
Minimum Cost ◽  
Cost Effective ◽  
Maintenance Cost ◽  
Cost Of Energy ◽  
Finite State ◽  
Evaluation Metric ◽  
Cost Parameters ◽  
The Cost

Nowadays the cost effectiveness concept becomes a decision-making and technology evaluation metric. The cost of energy metric accounts for the effect of reliability through levelized replacement cost and unscheduled maintenance cost parameters. One key of the proposed approach is the idea of maintaining the WTs which can be captured via use of a finite state Markov chain. Such a model can be embedded within a probabilistic operation and maintenance simulation reflecting the action to be done. In this paper a finite state Markov model is used for decision problems with number of determined periods (life cycle) to predict the cost according to the option of the maintenance adopted. The minimum cost is taken as the optimal solution.

scholarly journals Scheduling Preventive Maintenance on Auto Rooting Machine at Toys Manufacturer Company

2016 ◽  
Vol 5 (1) ◽  
pp. 26
Author(s):  
Anastasia Lidya Maukar ◽  
Ineu Widaningsih Sosodoro ◽  
Rhiza Adiprabowo
Keyword(s):  
Preventive Maintenance ◽  
Cost Model ◽  
Minimum Cost ◽  
Maintenance Cost ◽  
Interval Time ◽  
Maintenance Schedule ◽  
Maintenance System ◽  
Machine Reliability ◽  
The Right ◽  
Time Of Failure

<p>Maintenance cost becomes one of the problems that manufacturing company is facing nowadays due to<br />lack of maintenance system. The main objective of this research is to reduce the maintenance cost on auto<br />rooting machine in toy manufacturer by developing a scheduled preventive maintenance. Data of machine<br />breakdowns and costs related to maintenance, components, and the interval time of failure for each machine<br />were collected. To develop a preventive maintenance system, the interval of component replacement must be<br />determined. The minimum cost model is attained by finding the right interval time. The result of this research<br />shows that by implementing proposed maintenance schedule the machine reliability has 45% increase and<br />maintenance cost decreases by 48%.</p>

A generalized fuzzy cost efficiency model

2020 ◽  
Vol 54 (6) ◽  
pp. 1775-1791
Author(s):  
Nazila Aghayi ◽  
Samira Salehpour
Keyword(s):  
Cost Efficiency ◽  
Minimum Cost ◽  
Extensive Literature ◽  
Data Envelopment ◽  
Fuzzy Environment ◽  
Decision Making Unit ◽  
Production Possibility Set ◽  
Fuzzy Cost ◽  
The Cost ◽  
Generalized Cost

The concept of cost efficiency has become tremendously popular in data envelopment analysis (DEA) as it serves to assess a decision-making unit (DMU) in terms of producing minimum-cost outputs. A large variety of precise and imprecise models have been put forward to measure cost efficiency for the DMUs which have a role in constructing the production possibility set; yet, there’s not an extensive literature on the cost efficiency (CE) measurement for sample DMUs (SDMUs). In an effort to remedy the shortcomings of current models, herein is introduced a generalized cost efficiency model that is capable of operating in a fuzzy environment-involving different types of fuzzy numbers-while preserving the Farrell’s decomposition of cost efficiency. Moreover, to the best of our knowledge, the present paper is the first to measure cost efficiency by using vectors. Ultimately, a useful example is provided to confirm the applicability of the proposed methods.

Main approaches to estimating the cost of shareholder equity of oil and gas producers

2020 ◽  
Vol 26 (3) ◽  
pp. 685-697
Author(s):  
O.V. Shimko
Keyword(s):  
Oil And Gas ◽  
Oil Prices ◽  
Minimum Cost ◽  
Free Cash Flow ◽  
Annual Reports ◽  
Comparative Approach ◽  
Economic Activities ◽  
Advantages And Disadvantages ◽  
Oil And Gas Producers ◽  
The Cost

Subject. The study analyzes generally accepted approaches to assessing the value of companies on the basis of financial statement data of ExxonMobil, Chevron, ConocoPhillips, Occidental Petroleum, Devon Energy, Anadarko Petroleum, EOG Resources, Apache, Marathon Oil, Imperial Oil, Suncor Energy, Husky Energy, Canadian Natural Resources, Royal Dutch Shell, Gazprom, Rosneft, LUKOIL, and others, for 1999—2018. Objectives. The aim is to determine the specifics of using the methods of cost, DFC, and comparative approaches to assessing the value of share capital of oil and gas companies. Methods. The study employs methods of statistical analysis and generalization of materials of scientific articles and official annual reports on the results of financial and economic activities of the largest public oil and gas corporations. Results. Based on the results of a comprehensive analysis, I identified advantages and disadvantages of standard approaches to assessing the value of oil and gas producers. Conclusions. The paper describes pros and cons of the said approaches. For instance, the cost approach is acceptable for assessing the minimum cost of small companies in the industry. The DFC-based approach complicates the reliability of medium-term forecasts for oil prices due to fluctuations in oil prices inherent in the industry, on which the net profit and free cash flow of companies depend to a large extent. The comparative approach enables to quickly determine the range of possible value of the corporation based on transactions data and current market situation.

scholarly journals Effects of Increase in the Cost of Building Materials on the Delivery of Affordable Housing in South Africa

2021 ◽  
Vol 13 (4) ◽  
pp. 1772
Author(s):  
Bimpe Alabi ◽  
Julius Fapohunda
Keyword(s):  
South Africa ◽  
Affordable Housing ◽  
Building Materials ◽  
Statistical Technique ◽  
Project Managers ◽  
Maintenance Cost ◽  
Cost Increase ◽  
Sequential Mixed Methods ◽  
Adequate Provision ◽  
The Cost

Adequate provision of affordable human settlements is a huge challenge in South Africa since its independence. This paper investigates the effects of the cost increase of building materials on affordable housing delivery in South Africa. With potential solutions for cost minimisation of building materials, with the aim of achieving affordable housing delivery in South Africa are provided. This study uses a sequential mixed methods approach, wherein surveys were conducted among the construction professionals (project managers, site managers architects, site engineers, quantity surveyors, contractors, building materials suppliers, and government workers) in the construction industry within Cape Town, South Africa, who were considered as the research participants. The qualitative data obtained from the survey exercise were analysed using content analysis, while the quantitative data were analysed using a descriptive statistical technique on SPSS. The findings attained show fluctuation in construction cost and a rise in maintenance cost (caused by poor workmanship) as significant effects in the cost increase of building materials for affordable housing delivery. Adequate application of the recommendations given in this study will minimise the effects of high cost of building materials and enhance affordable housing delivery. Appropriate handling of the findings given in this study will reduce the effects of the high cost of building materials and augment timely delivery of affordable housing and stakeholders’ satisfaction.

scholarly journals Analysis and Optimization of a Novel Hexagonal Waveguide Concentrator for Solar Thermal Applications

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2146
Author(s):  
Karunesh Kant ◽  
Karthik Nithyanandam ◽  
Ranga Pitchumani
Keyword(s):  
Industrial Process ◽  
Cost Effective ◽  
Solar Irradiation ◽  
Maintenance Cost ◽  
Solar Concentrator ◽  
Thermal Desalination ◽  
Process Heat ◽  
Solar Thermal Applications ◽  
The Cost ◽  
Operation And Maintenance Cost

This paper analyzes a novel, cost-effective planar waveguide solar concentrator design that is inspired by cellular hexagonal structures in nature with the benefits of facile installation and low operation and maintenance cost. A coupled thermal and optical analysis of solar irradiation through an ideal hexagonal waveguide concentrator integrated with a linear receiver is presented, along with a cost analysis methodology, to establish the upper limit of performance. The techno-economic model, coupled with numerical optimization, is used to determine designs that maximized power density and minimized the cost of heat in the temperature range of 100–250 °C, which constitutes more than half of the industrial process heat demand. Depending on the incident solar irradiation and the application temperature, the cost of heat for the optimal design configuration ranged between 0.1–0.27 $/W and 0.075–0.18 $/W for waveguide made of ZK7 glass and polycarbonate, respectively. A techno-economic analysis showed the potential of the technology to achieve cost as low as 80 $/m2 and 61 $/m2 for waveguide made of ZK7 glass and polycarbonate material, respectively, which is less than half the cost of state-of-the-art parabolic trough concentrators. Overall, the hexagonal waveguide solar concentrator technology shows immense potential for decarbonizing the industrial process heat and thermal desalination sectors.

A claims problem approach to the cost allocation of a minimum cost spanning tree

2021 ◽  
Author(s):  
José-Manuel Giménez-Gómez ◽  
Josep E. Peris ◽  
Begoña Subiza
Keyword(s):  
Spanning Tree ◽  
Cost Allocation ◽  
Minimum Cost ◽  
Claims Problem ◽  
The Cost

Enterprise Inventory Control Based on Supply Chain Management

2012 ◽  
Vol 472-475 ◽  
pp. 3273-3276
Author(s):  
Qing Ying Zhang ◽  
Ying Chi ◽  
Yu Liu ◽  
Qian Shi
Keyword(s):  
Supply Chain ◽  
Supply Chain Management ◽  
Inventory Control ◽  
Control Strategies ◽  
Minimum Cost ◽  
Chain Management ◽  
Main Target ◽  
The Cost

The main target of supply chain management is to control inventory of each node enterprise effectively with the minimum cost. In this paper, the control strategies and methods of inventory based on supply chain management are put forward, which are significant for saving the cost of supply chain and improving the overall benefits of the whole chain.

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