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    A New Model for Track Maintenance Management System (Case study: Iranian Railway)

    , M.Sc. Thesis Sharif University of Technology Share Isfahani, Hajar (Author) ; Shafahi, Yusof (Supervisor)
    Abstract
    Railway managers have strong economic incentive to minimize the cost of track maintenance in order to conserve safety standards and provide adequate service levels for train operators. The main object of this study is to provide a method for railway repairing and maintaining management and improve previous researchs.
    In this study, a cumulative damage model based upon a nonhomogeneous Markov process is developed to model track deterioration. The maintenance of deteriorating facilities can be a great challenge because the process of deteriorating has random features for some facilities.
    The genetic algorithm is used to find the optimal repair for each possible track state in the... 

    A Track Maintenance Management Model Using Heuristic Model (Case of Study: Iranian Railway)

    , M.Sc. Thesis Sharif University of Technology Ahmadi, Ehsan (Author) ; Shafahi, Yusof (Supervisor)
    Abstract
    Railways managers have strong economic incentive to minimize the track maintenance costs, while maintaining safety standards and providing adequate service levels to train operators. . The aim of this study is providing a method for repair and maintenance management of Iranian Railways and improving previous investigations.This study consists of three parts. First, providing a new definition for the rail's status based on fuzzy theory. Second, a cumulative damage model based on a Fuzzy Markov process is applied to model the deterioration of the track. For this reason, tracks are categorized into six classes, so that those tracks with similar traffic loads and geographical location are... 

    Application of Machine Learning Algorithms on Railway Track Deterioration Modeling

    , M.Sc. Thesis Sharif University of Technology Sedighi, Alireza (Author) ; Shafahi, Yosef (Supervisor)
    Abstract
    The vital and influential role of railways in the socio-economic growth and development of countries, along with the high costs of rehabilitation and maintenance of its infrastructure, has made the existence of a comprehensive maintenance management system a necessity to not only elevate the level of service, reliability, and safety but also to minimize such repair costs. Accurate modeling of track deterioration is essential as one of the components of such systems.In this study, a large database from outputs of EM120, track recording machine, was provided for the years 2009 to 2018 and for all 18 railway zones of Iranian Railways (approximately 13,000 km railway track and 80 GB of data).... 

    Novel adaptive Kalman filtering and fuzzy track fusion approach for real time applications

    , Article 2008 3rd IEEE Conference on Industrial Electronics and Applications, ICIEA 2008, Singapore, 3 June 2008 through 5 June 2008 ; 2008 , Pages 120-125 ; 9781424417186 (ISBN) Dehghani Tafti, A ; Sadati, N ; Sharif University of Technology
    2008
    Abstract
    The track fusion combines individual tracks formed by different sensors. Tracks are usually obtained by Kalman Filter (KF), since it is suitable for real-time application. The KF is an optimal linear estimator when the measurement noise has a Gaussian distribution with known covariance. However, in practice, some of the sensors do not have these properties, and the traditional KF is not an optimal estimator. In this paper, a novel adaptive Kalman filter (NAKF) is proposed. In this approach, the measurement noise covariance is adjusted by using an introduced simple mathematical function of one variable, called the degree of matching (DoM), where it is defined on the basis of covariance...