- document
-
Bolin, David (author), Kirchner, K. (author)We consider two Gaussian measures μ, ˜μ on a separable Hilbert space, with fractional-order covariance operators A<sup>−2β</sup> and Ã<sup>−2˜β</sup>, respectively, and derive necessary and sufficient conditions on A, Ã and β, ˜β > 0 for I. equivalence of the measures μ and ˜μ, and II. uniform asymptotic optimality of linear predictions...journal article 2023
- document
-
Sadowy-Sadowski, Tomasz (author)The concept of a spaceplane, a launch system that is a combination of an airplane and a rocket, is one of the most promising concepts of sustainable access to space. Along its trajectory, it experiences most extreme conditions with frequently opposing design requirements, making it one of the most complicated challenges in aerospace engineering....master thesis 2022
- document
-
MUHAMMAD RAYYAN, Rayyan (author)Using an expensive-to-evaluate numerical model, such as a finite element method (FEM) model, is deemed unavoidable in solving modern geotechnical engineering problems. At the same time, the application of reliability analysis in dealing with uncertainties (e.g. soil properties) is increasing rapidly. This could pose a time-wise problem for an...master thesis 2022
- document
-
Ordeman, Sam (author)Digital Soil Mapping (DSM) of soil types in geotechnical project areas is a top priority. These maps are often used in decision making and can have significant consequences related to costs and risks. Usually, these maps are generated by digital soil models that interpolate soil types at known locations. In practice, conventional spatial...master thesis 2022
- document
-
Di Curzio, Diego (author), Di Giovanni, Alessia (author), Lidori, Raffaele (author), Montopoli, Mario (author), Rusi, Sergio (author)Accurate knowledge of the rain amount is a crucial driver in several hydrometeorological applications. This is especially true in complex orography territories, which are typically impervious, thus, leaving most mountain areas ungauged. Due to their spatial and temporal coverage, weather radars can potentially overcome such an issue. However,...journal article 2022
- document
-
Kirchner, K. (author), Bolin, David (author)Optimal linear prediction (aka. kriging) of a random field {Z(x)} x∈X indexed by a compact metric space (X, dX ) can be obtained if the mean value function m: X →R and the covariance function ∂: X × X →R of Z are known. We consider the problem of predicting the value of Z(x*) at some location x*∈ X based on observations at locations {xj }nj ...journal article 2022
- document
-
Dos Santos, Rogério R. (author), Castro, Saullo G.P. (author)The present study investigates how to apply continuous tow shearing (CTS) in a manufacturable design parameterization to obtain reduced imperfection sensitivity in lightweight, cylindrical shell designs. The asymptotic nonlinear method developed by Koiter is applied to predict the postbuckled stiffness, whose index is constrained to be...journal article 2022
- document
-
van den Eijnden, A.P. (author), Schweckendiek, T. (author), Hicks, M.A. (author)A kriging-based metamodelling approach for analysing the structural reliability of a sheetpile wall in a dyke is formulated. This specific problem is characterised by high target reliabilities ((Formula presented.)) in combination with a noisy and incomplete numerical model response. Starting from the original formulation of active learning...journal article 2021
- document
-
Teixeira, Rui (author), Martinez-Pastor, Beatriz (author), Nogal Macho, M. (author), O'Connor, Alan (author)The present work discusses an innovative approach to metamodeling in reliability that uses a field-transversal rationale. Adaptive metamodeling in reliability is characterized by its large spectra of models and techniques with different assumptions. As a result, the reliability engineer is frequently faced with the highly challenging task of...journal article 2021
- document
-
Teixeira, Rui (author), Nogal Macho, M. (author), O'Connor, Alan (author)The present work reviews the implementation of adaptive metamodeling for reliability analysis with emphasis in four main types of metamodels: response surfaces, polynomial chaos expansions, support vector machines, and Kriging models. The discussion presented is motivated by the identified spread and little interaction between metamodeling...journal article 2021
- document
-
Varouchakis, Emmanouil A. (author), Hristopulos, Dionissios T. (author), Karatzas, George P. (author), Corzo Perez, GA (author), Diaz, Vitali (author)Precipitation data are useful for the management of water resources as well as flood and drought events. However, precipitation monitoring is sparse and often unreliable in regions with complicated geomorphology. Subsequently, the spatial variability of the precipitation distribution is frequently represented incorrectly. Satellite...journal article 2021
- document
-
Yin, Jiapeng (author), Schleiss, M.A. (author), Wang, Xuesong (author)The use of spectral polarimetric filters in the range-Doppler domain shows great promise for clutter mitigation in weather radar applications. One limitation of these filters is that they cannot deal with situations in which ground clutter and precipitation overlap. In this letter, we propose a new signal recovery technique based on kriging in...journal article 2021
- document
-
Wang, Z. (author), Almeida, José Humberto S. (author), St-Pierre, Luc (author), Wang, Zhonglai (author), Castro, Saullo G.P. (author)A reliability-based optimization framework is introduced and used to design filament-wound cylindrical shells with variable angle tow. Seven design cases are investigated to enable a comparison between constant-stiffness and variable angle tow designs, also considering effects of thickness variation created due to overlapping tow paths,...journal article 2020
- document
-
Chuang, Jia Shian (author)This research aims to develop a method to create a wind farm layout that is robust against the uncertainty source, the inter-year variation of Weibull parameters and wind direction sector probabilities. A wind farm layout optimisation problem under uncertainty corresponds to optimisation under uncertainty (OUU), which is computationally...master thesis 2020
- document
-
Turan, O.T. (author)Various engineering applications rely on efficient, high performance materials to overcome design challenges. This high performance can be achieved by engineering micro-heterogenous materials also known as composites. Since the behavior of composites relies heavily on micro-scale interactions between different components, modeling...master thesis 2020
- document
-
Casella, S.G. (author)The thesis proposes a methodology for a Surrogate Based Optimisation (SBO) study and its application in the Naval Architecture field using the open-source software DAKOTA. Surrogate Based Optimisation is a useful and powerful way of reducing time and costs in hull shape optimisation. It allows the employ of exploratory data analysis techniques...master thesis 2020
- document
-
Nederpel, Wolf (author)In this thesis a model for interpolation of magnetic fields is constructed using Gaussian processes. This model takes the curl- and divergence-free properties of magnetic fields into account. The Gaussian process regression, or kriging, is tested on both simulated and real data. It is also attempted to reconstruct the magnetization of objects...bachelor thesis 2020
- document
-
Teixeira, Rui (author), Nogal Macho, M. (author), O'Connor, Alan (author), Martinez-Pastor, Beatriz (author)Reliability assessment with adaptive Kriging has gained notoriety due to the Kriging capability of accurately replacing the performance function while performing as a self-improving function for learning procedures. Recent works on adaptive Kriging pursued to improve the efficiency of the active learning through the application of distinct...journal article 2020
- document
-
Ma, H. (author), Zhao, Qile (author), Verhagen, S. (author), Psychas, D.V. (author), Dun, H. (author)This contribution implements the Kriging interpolation in predicting the tropospheric wet delays using global navigation satellite system networks. The predicted tropospheric delays can be used in strengthening the precise point positioning models and numerical weather prediction models. In order to evaluate the performances of the Kriging...journal article 2020
- document
-
Fatou Gomez, Javier (author)The computation of complex turbulent flows design optimization processes is currently limited by the lack of accuracy of Reynolds-Averaged Navier-Stokes (RANS) in massively separated flows and the infeasible cost of multiple Large-Eddy Simulation (LES) evaluations. A novel method is presented, injecting data from LES or other high-fidelity...master thesis 2018