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- Stroetmann, Jan Felix (author), Wagner, Julia (author), Nunez, Miguel (author) conference paper 2024
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Kapoor, T. (author), Wang, H. (author), Nunez, Alfredo (author), Dollevoet, R.P.B.J. (author)This paper proposes a novel framework for simulating the dynamics of beams on elastic foundations. Specifically, partial differential equations modeling Euler–Bernoulli and Timoshenko beams on the Winkler foundation are simulated using a causal physics-informed neural network (PINN) coupled with transfer learning. Conventional PINNs encounter...journal article 2024
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Zeng, Y. (author), Nunez, Alfredo (author), Li, Z. (author)A train-borne laser Doppler vibrometer (LDV) directly measures the dynamic response of railway track components from a moving train, which has the potential to complement existing train-borne technologies for railway track monitoring. This paper proposes a holistic methodology to characterize train-borne LDV measurements by combining computer...journal article 2024
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Unsiwilai, S. (author), Shen, C. (author), Zeng, Y. (author), Wang, L. (author), Nunez, Alfredo (author), Li, Z. (author)This study presents a measuring framework for railway transition zones using a case study on the Swedish line between Boden and Murjek. The final goal is to better understand the vertical dynamics of transition zones using hammer tests, falling weight measurements, and axle box acceleration (ABA) measurements. Frequency response functions ...journal article 2024
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Kapetanović, M. (author), Nunez, Alfredo (author), van Oort, N. (author), Goverde, R.M.P. (author)This paper presents a method for estimating Well-to-Wheel (WTW) energy use and greenhouse gas (GHG) emissions attributed to the advanced railway propulsion systems implemented in conjunction with different energy carriers and their production pathways. The analysis encompasses diesel-electric multiple unit vehicles converted to their hybrid...journal article 2024
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Zeng, Y. (author), Nunez, Alfredo (author), Li, Z. (author)A transfer function (TF) is an effective representation of the load-response relationship of railway track structures. To fill the gap in measuring track structure TFs over a wide frequency range from a moving vehicle, we develop a TF measurement system and the associated TF estimation methodology. Accelerometers are utilized to estimate the...journal article 2024
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Kapoor, T. (author), Chandra, Abhishek (author), Tartakovsky, Daniel M. (author), Wang, H. (author), Nunez, Alfredo (author), Dollevoet, R.P.B.J. (author)A primary challenge of physics-informed machine learning (PIML) is its generalization beyond the training domain, especially when dealing with complex physical problems represented by partial differential equations (PDEs). This paper aims to enhance the generalization capabilities of PIML, facilitating practical, real-world applications where...journal article 2024
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Wang, L. (author), Unsiwilai, S. (author), Zeng, Y. (author), Shen, C. (author), Hendriks, J.M. (author), Moraal, J. (author), Zoeteman, A. (author), Nunez, Alfredo (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)Railway transition zones connecting conventional embankments and rigid struc-tures, such as bridges and tunnels, usually degrade much faster than other railway sections. Efficient health condition monitoring of transition zones is important for preventative track maintenance. In this paper, a methodology for monitoring rail-way transition zones...conference paper 2024
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Unsiwilai, S. (author), Wang, L. (author), Nunez, Alfredo (author), Li, Z. (author)This paper presents a methodology for monitoring transition zones using responses of multiple-axle box acceleration (multi-ABA) measurements. The time–frequency characteristics of the vertical ABA signals from four wheelsets are analyzed. The major contributions are as follows. (1) We propose four key performance indicators (KPIs) to quantify...journal article 2023
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Fu, J. (author), Nunez, Alfredo (author), De Schutter, B.H.K. (author)To ensure the reliability of power systems, the independent system operator (ISO) manages the planning process of the maintenance of generation units for generation companies (GENCOs). This paper focuses on a widely studied two-layer long-term predictive maintenance decision making framework in a deregulated environment. In the first layer...journal article 2023
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Kapetanović, M. (author), Nunez, Alfredo (author), van Oort, N. (author), Goverde, R.M.P. (author)Hydrogen fuel cell multiple unit vehicles are acquiring a central role in the transition process towards carbon neutral trains operation in non-electrified regional railway networks. In addition to their primary role as a transport mean, these vehicles offer significant potential for applications in innovative concepts such as smart grids....abstract 2023
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Zeng, Y. (author), Shen, C. (author), Nunez, Alfredo (author), Dollevoet, R.P.B.J. (author), Zhang, Weihua (author), Li, Z. (author)Operational modal analysis (OMA) enables the identification of modal characteristics under operational loads and conditions. Traditional frequency-domain methods cannot directly capture modal changes over time, while existing time-frequency representations are not sufficiently interpretable due to spurious modes and implicit parameter design....journal article 2023
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Morales, Raúl (author), Marín, Luis G. (author), Roje, Tomislav (author), Caquilpan, Víctor (author), Sáez, Doris (author), Nunez, Alfredo (author)Microgrids (MGs) are sustainable solutions for rural zone electrification that use local renewable resources. However, only careful planning at the start of an MG project can ensure its future optimal operation. In this paper, a novel methodology for MG planning by using the uncertainty characterization of renewable resources and demand is...journal article 2023
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Kapetanović, M. (author), Nunez, Alfredo (author), van Oort, N. (author), Goverde, R.M.P. (author)Hydrogen fuel cell multiple unit vehicles are acquiring a central role in the transition process towards carbon neutral trains operation in non-electrified regional railway networks. In addition to their primary role as a transport mean, these vehicles offer significant potential for applications in innovative concepts such as smart grids....journal article 2023
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Kapoor, T. (author), Wang, H. (author), Nunez, Alfredo (author), Dollevoet, R.P.B.J. (author)This article proposes a new framework using physics-informed neural networks (PINNs) to simulate complex structural systems that consist of single and double beams based on Euler–Bernoulli and Timoshenko theories, where the double beams are connected with a Winkler foundation. In particular, forward and inverse problems for the...journal article 2023
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Vernaillen, T. (author), Wang, L. (author), Nunez, Alfredo (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)This paper presents a big data-based analysis of the rail wear of the whole Belgian railway network measured in 2012 and 2019. Wear rates are reported, discussed, and quantitatively formulated as functions of critical factors in terms of curve radius, annual tonnage (rail age), high rail in curves, an average from both rails in straight...journal article 2023
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Fu, J. (author), Peyghami, Saeed (author), Nunez, Alfredo (author), Blaabjerg, Frede (author), De Schutter, B.H.K. (author)Predictive maintenance scheduling of modular-multilevel-converters (MMCs) requires estimations of the failure probabilities of MMCs during a period of time in the future. Particularly, the predicted future failure probabilities are influenced by two main factors, the mission profiles of the MMCs and the maintenance decisions on the MMCs...journal article 2023
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Zeng, Y. (author), Nunez, Alfredo (author), Li, Z. (author)Due to train load and aging, the dynamic properties of railway tracks degrade over time and deviate over space, which should be monitored to facilitate track maintenance decisions. A train-borne laser Doppler vibrometer (LDV) can directly measure track vibrations in response to the moving train load, which can be potentially applied to large...conference paper 2023
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Zeng, Y. (author), Nunez, Alfredo (author), Li, Z. (author)Speckle noise is a major problem for structural vibration measurements with Laser Doppler vibrometer on moving platform (LDVom) due to its highly random, frequent, and broadband nature, especially at high speeds. This paper develops a new post-processing framework to reduce speckle noise based on a case study of LDVom measurements on railway...journal article 2022
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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