1,338 research outputs found

    3D digital modelling and identification of pavement typical internal defects based on GPR measured data

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    A three-dimensional ground-penetrating radar (GPR) captures non-destructively internal pavement distress characteristics. However, interpreting radar images and data analysis pose challenges. To improve the accuracy of distress identification, a three-dimensional digital model of internal pavement distress was established. Firstly, initial electromagnetic signal data were pre-processed to effectively eliminate spurious signals and enhance distress characteristic signals. The distress was located, and GPR images of typical distress were extracted and summarised. Next, the 3D dataset was constructed based on the pre-processed electromagnetic echo signals. A 3D digital model of internal pavement distress was generated using the inverse distance weight and ray-casting methods with trilinear interpolation. Finally, relying on the physical project, cores were extracted to validate the distress model. The method effectively reflects the internal pavement distress, and enables realise the interactive images between the pavement entity and the digital model, which can essentially contribute to the digital twin of pavement systems

    Functional Nanomaterials and Polymer Nanocomposites: Current Uses and Potential Applications

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    This book covers a broad range of subjects, from smart nanoparticles and polymer nanocomposite synthesis and the study of their fundamental properties to the fabrication and characterization of devices and emerging technologies with smart nanoparticles and polymer integration

    Design of decorative 3D models: from geodesic ornaments to tangible assemblies

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    L'obiettivo di questa tesi è sviluppare strumenti utili per creare opere d'arte decorative digitali in 3D. Uno dei processi decorativi più comunemente usati prevede la creazione di pattern decorativi, al fine di abbellire gli oggetti. Questi pattern possono essere dipinti sull'oggetto di base o realizzati con l'applicazione di piccoli elementi decorativi. Tuttavia, la loro realizzazione nei media digitali non è banale. Da un lato, gli utenti esperti possono eseguire manualmente la pittura delle texture o scolpire ogni decorazione, ma questo processo può richiedere ore per produrre un singolo pezzo e deve essere ripetuto da zero per ogni modello da decorare. D'altra parte, gli approcci automatici allo stato dell'arte si basano sull'approssimazione di questi processi con texturing basato su esempi o texturing procedurale, o con sistemi di riproiezione 3D. Tuttavia, questi approcci possono introdurre importanti limiti nei modelli utilizzabili e nella qualità dei risultati. Il nostro lavoro sfrutta invece i recenti progressi e miglioramenti delle prestazioni nel campo dell'elaborazione geometrica per creare modelli decorativi direttamente sulle superfici. Presentiamo una pipeline per i pattern 2D e una per quelli 3D, e dimostriamo come ognuna di esse possa ricreare una vasta gamma di risultati con minime modifiche dei parametri. Inoltre, studiamo la possibilità di creare modelli decorativi tangibili. I pattern 3D generati possono essere stampati in 3D e applicati a oggetti realmente esistenti precedentemente scansionati. Discutiamo anche la creazione di modelli con mattoncini da costruzione, e la possibilità di mescolare mattoncini standard e mattoncini custom stampati in 3D. Ciò consente una rappresentazione precisa indipendentemente da quanto la voxelizzazione sia approssimativa. I principali contributi di questa tesi sono l'implementazione di due diverse pipeline decorative, un approccio euristico alla costruzione con mattoncini e un dataset per testare quest'ultimo.The aim of this thesis is to develop effective tools to create digital decorative 3D artworks. Real-world art often involves the use of decorative patterns to enrich objects. These patterns can be painted on the base or might be realized with the application of small decorative elements. However, their creation in digital media is not trivial. On the one hand, users can manually perform texture paint or sculpt each decoration, in a process that can take hours to produce a single piece and needs to be repeated from the ground up for every model that needs to be decorated. On the other hand, automatic approaches in state of the art rely on approximating these processes with procedural or by-example texturing or with 3D reprojection. However, these approaches can introduce significant limitations in the models that can be used and in the quality of the results. Instead, our work exploits the recent advances and performance improvements in the geometry processing field to create decorative patterns directly on surfaces. We present a pipeline for 2D and one for 3D patterns and demonstrate how each of them can recreate a variety of results with minimal tweaking of the parameters. Furthermore, we investigate the possibility of creating decorative tangible models. The 3D patterns we generate can be 3D printed and applied to previously scanned real-world objects. We also discuss the creation of models with standard building bricks and the possibility of mixing standard and custom 3D-printed bricks. This allows for a precise representation regardless of the coarseness of the voxelization. The main contributions of this thesis are the implementation of two different decorative pipelines, a heuristic approach to brick construction, and a dataset to test the latter

    30th European Congress on Obesity (ECO 2023)

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    This is the abstract book of 30th European Congress on Obesity (ECO 2023

    Decision-making with gaussian processes: sampling strategies and monte carlo methods

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    We study Gaussian processes and their application to decision-making in the real world. We begin by reviewing the foundations of Bayesian decision theory and show how these ideas give rise to methods such as Bayesian optimization. We investigate practical techniques for carrying out these strategies, with an emphasis on estimating and maximizing acquisition functions. Finally, we introduce pathwise approaches to conditioning Gaussian processes and demonstrate key benefits for representing random variables in this manner.Open Acces

    Essays on Portfolio Risk Management and Weather Derivatives

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    Denne avhandlingen handler om utvikling og praktisk implementering av risikostyringsmetoder for investeringsporteføljer, energiporteføljer, og håndtering av vær- og forurensningsrisiko. Avhandlingen inkluderer tre vitenskapelige artikler som hver tar for seg ulike aspekter av finansiell risikostyring. Den første fokuserer på metoder for aktivaallokering når det eksisterer asymmetrisk avhengighet mellom avkastningene for eiendelene i en investeringsportefølje. Den andre artikkelen omhandler energiprisrisikostyring, og introduserer et åpen kildekodeverktøy for energiporteføljeforvaltning som er utviklet som en del av doktorgradsprosjektet. Den siste artikkelen presenterer et teoretisk rammeverk for håndtering av forurensningsrisiko ved hjelp av finansielle derivatkontrakter, som bygger på den eksisterende teorien om værderivater. Disse arbeidene bidrar alle til det overordnede temaet for avhandlingen, som er utvikling av risikostyringsmetoder for ulike typer porteføljer og utforskingen av rollen til finansielle derivater i håndtering av risiko knyttet til markedspriser, vær og forurensning. For å sette bidragene inn i en teoretisk kontekst har vi inkludert et kort kapittel som presenterer alternative metoder for avhengighetsmodellering, og hvordan disse kan utnyttes når man forvalter investeringsporteføljer. Ett av disse målene, lokal gaussisk korrelasjon, brukes til å utvide det klassiske mean-variance-rammeverket for aktivaallokering i den første artikkelen. Deretter følger et kort introduksjonskapittel til spot- og forwardmarkeder for energi. Hovedfokuset her er råvareprisrisiko, og hvordan denne kan håndteres med finansielle derivatkontrakter. Vi demonstrerer hvordan forvaltning av energiporteføljer kan gjennomføres med vårt åpen kildekodeverktøy ved bruk av data fra det europeiske kraftmarkedet. Til slutt inkluderes et kapittel om værderivater. Dette inneholder en introduksjon til værrelatert risiko, en kort introduksjon til værmarkedet, vanlige kontraktstyper og alternative metoder for prising. For å sikre reproduserbarhet har vi også lagt til et kapittel om programkode. Her finnes lenker til Git-repositorier med alle data og R-kode for å gjennomføre analysene som presenteres i avhandlingen.This thesis is concerned with the development and practical implementation of risk management methods for investment portfolios, energy portfolios, and weather and pollution risk. The thesis includes three scientific papers that each address different aspects of financial risk management. The first paper focuses on portfolio allocation in the presence of asymmetric dependence between asset returns. The second paper examines energy price risk management, and introduces an open source toolkit for energy portfolio management which has been developed as a part of the PhD project. The final paper present a theoretical framework for managing pollution risk using financial derivatives contracts, which builds upon the existing theory of weather derivatives. These papers all contribute to the overall theme, which is the development of risk management methods for various types of portfolios and the exploration of the role of financial derivatives in managing risks related to market prices, weather and pollution. In order to provide a theoretical context, we have included a brief chapter exploring alternative methods for dependence modelling and how these may be utilized when managing investment portfolios. One of these measures, the local Gaussian correlation, is used to extend the classical mean-variance framework for asset allocation in the first paper. Thereafter, a short introduction to spot and forward energy markets is provided. The primary focus here is commodity market price risk, and how this can be managed with financial derivatives contracts. We demonstrate how portfolio management may be performed with our open source toolkit using European energy market data. Finally, we include a chapter on weather derivatives. This contains a introduction to weather related risk, a brief introduction to the weather markets, frequently used contract types and pricing methods. To ensure reproducibility, we have also added a chapter on computer code, where the interested reader may find links to Git repositories with all data and the R code needed to run the analysis presented in the thesis.Doktorgradsavhandlin

    Phase field modeling and computer implementation: A review

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    This paper presents an overview of the theories and computer implementation aspects of phase field models (PFM) of fracture. The advantage of PFM over discontinuous approaches to fracture is that PFM can elegantly simulate complicated fracture processes including fracture initiation, propagation, coalescence, and branching by using only a scalar field, the phase field. In addition, fracture is a natural outcome of the simulation and obtained through the solution of an additional differential equation related to the phase field. No extra fracture criteria are needed and an explicit representation of a crack surface as well as complex track crack procedures are avoided in PFM for fracture, which in turn dramatically facilitates the implementation. The PFM is thermodynamically consistent and can be easily extended to multi-physics problem by 'changing' the energy functional accordingly. Besides an overview of different PFMs, we also present comparative numerical benchmark examples to show the capability of PFMs

    University of Windsor Graduate Calendar 2023 Spring

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    https://scholar.uwindsor.ca/universitywindsorgraduatecalendars/1027/thumbnail.jp

    Structural optimization in steel structures, algorithms and applications

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    L'abstract è presente nell'allegato / the abstract is in the attachmen
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