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Shoja, Aydin (author), van der Neut, J.R. (author), Wapenaar, C.P.A. (author)Recently, the focus of reflection seismologists has shifted to applications where a high-resolution image of the subsurface is required. Least-Squares Reverse-Time Migration (LSRTM) is a common tool used to compute such images. Still, its high computational costs have led seismologists to use target-oriented LSRTM for imaging only a small target...journal article 2024
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Shoja, Aydin (author)Reflection seismology aims to estimate the Earth's subsurface elastic parameters for further investigation by geologists and engineers. This involves generating elastic waves using seismic sources and recording the Earth's response with receivers. The subsurface model is typically considered a combination of a background model and a short...doctoral thesis 2023
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Karimi, Hamed (author), Iran-Pour, Siavash (author), Amiri Simkooei, A. (author), Babadi, Masoud (author)Gravity recovery and climate experiment (GRACE) and GRACE Follow-On (GRACE-FO) are Earth's gravity satellite missions with hydrological monitoring applications. However, caused by measuring instrumental problems, there are several temporal missing values in the dataset of the two missions where a long gap between the mission dataset also...journal article 2023
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Naranjo, D. (author), Parisi, Laura (author), Jónsson, Sigurjón (author), Jousset, Philippe (author), Werthmüller, D. (author), Weemstra, C. (author)The timing of the recordings of ocean-bottom seismometers (OBSs) is critical for accurate earthquake location and Earth model studies. GNSS signals, however, cannot reach OBSs deployed at the ocean bottom. This prevents their clocks from being synchronized with a known reference time. To overcome this, we developed OCloC, a Python package that...abstract 2023
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Gholinejad, Saeid (author), Amiri Simkooei, A. (author)The weighted total least squares (WTLS) has been widely used in many geodetic problems to solve the error-in-variable (EIV) models in which both the observation vector and the design matrix contain random errors. This method is widely applied in its univariate form, where the observations and unknown coefficients appear in vector forms....journal article 2023
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Mancinelli, A. (author), Remes, B.D.W. (author), de Croon, G.C.H.E. (author), Smeur, E.J.J. (author)Hybrid Unmanned Aerial Vehicles UAV are vehicles capable of take-off and landing vertically like helicopters while maintaining the long-range efficiency of fixed-wing aircraft. Unfortunately, due to their wing area, these vehicles are sensitive to wind gusts when hovering. One way to increase the hovering wind-rejection capabilities of hybrid...journal article 2023
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Klees, R. (author), Slobbe, D.C. (author)This paper investigates the full variance–covariance (VC) matrix of two high-resolution regional quasi-geoid models, utilizing a spherical radial basis function parameterization. Model parameters were estimated using weighted least-squares techniques and variance component estimation (VCE) for data weighting. The first model, known as the ...journal article 2023
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Matheus, R. (author), Faber, R.M. (author), Ismagilova, Elvira (author), Janssen, M.F.W.H.A. (author)Open Government efforts are criticized for providing limited value. Instead of looking at a value, we investigate the usefulness of web-based open government portals and apps. Specifically, we investigated the relationship between digital transparency and usefulness. We analyzed perceived digital transparency and usefulness in a survey of 112...journal article 2023
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Mirmohammadian, Farinaz (author), Asgari, Jamal (author), Verhagen, S. (author), Amiri Simkooei, A. (author)Until now, RTK (real-time kinematic) and NRTK (Network-based RTK) have been the most popular cm-level accurate positioning approaches based on Global Navigation Satellite System (GNSS) signals in real-time. The tropospheric delay is a major source of RTK errors, especially for medium and long baselines. This source of error is difficult to...journal article 2022
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Mirmohammadian, Farinaz (author), Asgari, Jamal (author), Verhagen, S. (author), Amiri Simkooei, A. (author)With the advancement of multi-constellation and multi-frequency global navigation satellite systems (GNSSs), more observations are available for high precision positioning applications. Although there is a lot of progress in the GNSS world, achieving realistic precision of the solution (neither too optimistic nor too pessimistic) is still an...journal article 2022
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Baldi, S. (author), Zhang, Z. (author), Liu, Di (author)We propose a new reinforcement learning method in the framework of Recursive Least Squares-Temporal Difference (RLS-TD). Instead of using the standard mechanism of eligibility traces (resulting in RLS-TD((Formula presented.))), we propose to use the forgetting factor commonly used in gradient-based or least-square estimation, and we show that...journal article 2022
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Zhao, Zhijun (author), Yan, Gaowei (author), Ren, Mifeng (author), Cheng, Lan (author), Zhu, Zhujun (author), Pang, Y. (author)The traditional soft sensor models are based on the independent and identical distribution assumption, which are difficult to adapt to changes in data distribution under multiple operating conditions, resulting in model performance deterioration. The domain adaptive transfer learning methods learn knowledge in different domains by means of...journal article 2022
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Klees, R. (author), Seitz, K. (author), Slobbe, D.C. (author)In this paper, we derive improved expressions for the harmonic correction to gravity and, for the first time, expressions for the harmonic correction to potential and height anomaly. They need to be applied at stations buried inside the masses to transform internal values into harmonically downward continued values, which are then input to...journal article 2022
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Nibhanupudi, S.S. (author), Ishchenko, Anton (author), Tindemans, Simon H. (author), Palensky, P. (author)Transition from fossil fuels to sustainable sources of energy like wind and solar is the need of the hour. All over the globe, plans are in motion to achieve this goal. This implies addition of new elements to the grid in the form of Distributed Energy Resources (DERs). These affect the working of distribution grids and to ensure reliable as...conference paper 2022
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Petrov, N. (author), Yarovoy, Alexander (author)The calibration of a collocated MIMO radar is addressed by means of independent calibration of transmit and receive arrays. The solutions for both arrays' elements gain and phase terms only and the full coupling matrix estimation are presented. The proposed solution significantly improves over the conventional calibration of the virtual array...conference paper 2022
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van der Heijden, D.S. (author), Ledergerber, Anton (author), Gill, Rajan (author), D'Andrea, Raffaello (author)An iterative bias estimation framework is presented that mitigates position-dependent ranging errors often present in ultra-wideband localization systems. State estimation and control are integrated, such that the positioning accuracy improves over iterations. The framework is experimentally evaluated on a quadcopter platform, resulting in...journal article 2021
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Hosseini-Asl, Mahin (author), Amiri Simkooei, A. (author), Safari, Abdolreza (author)High precision geoid determination is a challenging task at the national scale. Many efforts have been conducted to determine precise geoid, locally or globally. Geoid models have different precision depending on the type of information and the strategy employed when calculating the models. This contribution addresses the challenging problem...journal article 2021
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Teunissen, P.J.G. (author), Massarweh, L. (author), Verhagen, S. (author)In this contribution, we extend the principle of integer bootstrapping (IB) to a vectorial form (VIB). The mathematical definition of the class of VIB-estimators is introduced together with their pull-in regions and other properties such as probability bounds and success rate approximations. The vectorial formulation allows sequential block...journal article 2021
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Mohammadi, S. (author), de Vries, Bauke (author), Rafiee, Azarakhsh (author), Esfandiari, Masoud (author), Dias, Eduardo (author)Applying any sustainable intervention in the urban energy system requires fundamental knowledge of the energy demand dynamics. Only when we can predict the users' energy demand at any given time with accuracy, we can redesign the urban energy system. Accordingly, the main objective of this paper is to determine the annual electricity usage of...journal article 2021
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Chavez, Jose J. (author), Veerakumar, Nidarshan (author), Azizi, Sadegh (author), Guardado, Jose L. (author), Rueda, José L. (author), Palensky, P. (author), Terzija, Vladimir (author), Popov, M. (author)Local protection elements such as fuses and relays are the first protective mechanism to clear the fault and isolate the affected part of the power grid. Although the selectivity, speed, and sensitivity of these primary protection devices are relatively high, they cannot be considered flawless. There is a small percentage of events for which...journal article 2021