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Fu, J. (author), Nunez, Alfredo (author), De Schutter, B.H.K. (author)Natural disasters pose a tremendous risk to the reliability of distribution networks. In this paper, a novel real-time UAV routing strategy for coordination between monitoring and inspection for post-disaster restoration in distribution networks is proposed. With our proposed real-time UAV routing strategy, damages can be inspected by UAVs...journal article 2022
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Wang, H. (author), Hendriks, J.M. (author), Dollevoet, R.P.B.J. (author), Zoeteman, Arjen (author), Nunez, Alfredo (author)Aiming to handle the increasing variety and volume of railway infrastructure monitoring data, this paper explores the use of intelligent data fusion methods for automatic anomaly detection of railway catenaries. Three classical data dimensionality reduction methods, namely the principal component analysis (PCA), the autoencoder neural network,...conference paper 2022
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Fu, J. (author), Nunez, Alfredo (author), De Schutter, B.H.K. (author)Maintenance of generation units is a measure to ensure the reliability of power systems. In this paper, a novel blockchain-based truthful condition-based maintenance of generation units (T-CBMGU) platform is proposed to innovate and upgrade state-of-the-art CBMGU. In addition, two valid inequalities are proposed to accelerate the convergence...journal article 2022
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Kapetanović, M. (author), Nunez, Alfredo (author), van Oort, N. (author), Goverde, R.M.P. (author)Non-electrified regional railway lines with typically employed diesel-electric multiple units require alternative propulsion systems to meet increasingly strict emissions regulations. With the aim to identify an optimal alternative to conventional diesel traction, this paper presents a model-based assessment of hydrogen-powered propulsion...journal article 2022
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Kapetanović, M. (author), Nunez, Alfredo (author), van Oort, N. (author), Goverde, R.M.P. (author)The railway sector is facing significant challenges in addressing the increasing concerns related to climate change, environmental pollution and scarcity of resources. This especially applies to often non-electrified regional railway networks, with passenger services provided by diesel-driven vehicles. Innovative propulsion system concepts offer...conference paper 2022
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Optimal network electrification plan for operation of battery-electric multiple unit regional trainsKapetanović, M. (author), Bešinović, Nikola (author), Nunez, Alfredo (author), van Oort, N. (author), Goverde, R.M.P. (author)The Netherlands have one of the highest rail electrification rates in the EU with over 75% of the railway network electrified (European Comission, 2018), offering environment-friendly trains operation. However, in order to achieve carbon neutral railway sector by 2050, significant investments are required to further improve environmental...abstract 2022
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Phusakulkajorn, W. (author), Hendriks, J.M. (author), Moraal, J. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author), Nunez, Alfredo (author)In this paper, a fuzzy interval-based method is proposed for solving the problem of rail defect detection relying on an on-board measurement system and a multiple spiking neural network architecture. Instead of outputting binary values (defect or not defect), all data will belong to both classes with different spreads that are given by two fuzzy...conference paper 2022
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Li, Z. (author), Li, S. (author), Zhang, P. (author), Nunez, Alfredo (author), Dollevoet, R.P.B.J. (author)This paper proposes a new hypothesis for the formation process of short pitch rail corrugation. An FE wheel-track dynamic model is utilized to verify the hypothesis by reproducing corrugation initiation and consistent growth. It is found longitudinal compression modes are responsible for corrugation initiation with necessary initial...journal article 2022
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Kapoor, T. (author), Wang, H. (author), Nunez, Alfredo (author), Dollevoet, R.P.B.J. (author)This paper addresses the problem of determining the distribution of the return current in electric railway traction systems. The dynamics of traction return current are simulated in all three space dimensions by informing the neural networks with the Partial Differential Equations (PDEs) known as telegraph equations. In addition, this work...conference paper 2022
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Zhong, Junping (author), Liu, Zhigang (author), Wang, H. (author), Liu, Wenqiang (author), Yang, Cheng (author), Han, Zhiwei (author), Nunez, Alfredo (author)Brace sleeve (BS) fasteners, i.e., nut and bolt, are small components but play essential roles in fixing BS and cantilever in railway catenary system. They are commonly inspected by onboard cameras using computer vision to ensure the safety of railway operation. However, most BS fasteners cannot be directly localized because they are too...journal article 2021
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Fu, J. (author), Nunez, Alfredo (author), De Schutter, B.H.K. (author)Preventive maintenance is applied in distribution networks to prevent failures by performing maintenance actions on components that are at risk. Distributed generators (DGs) and batteries can be used to support power to nearby loads when they are isolated due to maintenance. In this paper, a novel short-term preventive maintenance method is...journal article 2021
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Yang, Fei (author), Wei, Zilong (author), Sun, Xianfu (author), Shen, C. (author), Nunez, Alfredo (author)In this study, a wheel-rail transient rolling contact model capable of accounting for the nonlinear displacement-force properties of hanging sleepers is proposed. The sleeper hanging status affected by rail irregularities is an input for an analysis of the wheel-rail contact behavior and related rail degradation in terms of plastic...journal article 2021
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Zhang, P. (author), Li, S. (author), Nunez, Alfredo (author), Li, Z. (author)This paper investigates three-dimensional (3D) rail vibrations under fastening constraint up to 5000 Hz and provides insights into rail vibration control by fastening parameters. A methodology is proposed, including experimental investigation and numerical simulations of rail vibrations. Three steps are considered: 1) experimental investigation...journal article 2021
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Kapetanović, M. (author), Nunez, Alfredo (author), van Oort, N. (author), Goverde, R.M.P. (author)Hybridization of diesel multiple unit railway vehicles is an effective approach to reduce fuel consumption and related emissions in regional non-electrified networks. This paper is part of a bigger project realized in collaboration with Arriva, the largest regional railway undertaking in the Netherlands, to identify optimal solutions in...journal article 2021
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Zhang, P. (author), Li, S. (author), Nunez, Alfredo (author), Li, Z. (author)In this paper, we present a solution method based on finite element (FE) modeling to predict multimodal dispersive waves in a free rail. As well as the modal behaviors and wavenumber-frequency dispersion relations, the phase and group velocities of six types of propagative waves are also derived and discussed in detail in the frequency range...journal article 2021
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Liu, Wenqiang (author), Liu, Zhigang (author), Li, Qiao (author), Han, Zhiwei (author), Nunez, Alfredo (author)This article proposes an automatic high-precision detection method for structure parameters of catenary cantilever devices (SPCCDs) using 3-D point cloud data. The steps of the proposed detection method are: 1) segmenting and recognizing the components of the catenary cantilever devices, 2) extracting the detection plane and backbone...journal article 2020
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Wang, H. (author), Nunez, Alfredo (author)The catenary insulator maintains electrical insulation between catenary and ground. Its defects may happen due to the long-term impact from vehicle and environment. At present, the research of defect detection for catenary insulator faces several challenges. 1) Localization accuracy is low, which causes the localized object to be incomplete or...journal article 2020
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Zhong, J. (author), Liu, Zhigang (author), Wang, H. (author), Liu, W. (author), Yang, Cheng (author), Nunez, Alfredo (author)Brace Sleeve (BS) plays an essential role in connecting and fixing cantilevers of railway catenary systems. It needs to be monitored to ensure the safety of railway operations. In the literature, image processing techniques that can localize BSs from inspection images are proposed. However, the boxes produced by existing methods can contain...conference paper 2020
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Li, Z. (author), Berg, Mats (author), Fletcher, David (author), Meehan, Paul (author), Nunez, Alfredo (author)Editorialcontribution to periodical 2020
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Wei, Z. (author), Nunez, Alfredo (author), Liu, Xiubo (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)This study evaluates the degradation of wheels and rails at railway crossings. The evaluation method is composed of 1) finite element simulation of dynamic wheel/crossing interaction and 2) multi-criteria analysis of wheel/rail degradation in terms of yield behavior, rolling contact fatigue (RCF) and wear. With the aid of this method, we...journal article 2020