Theses authorised for defence

DOCTORAL DEGREE IN ARCHITECTURAL DESIGN

• ORTIGOSA DUARTE, NURIA: Exposiciones de arquitectura en Barcelona 1939-2019. Una colección.
  
  Author: ORTIGOSA DUARTE, NURIA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN ARCHITECTURAL DESIGN
  Department: Department of Architectural Design (PA)
  Mode: Normal
  Deposit date: 13/03/2025
  Reading date: 15/05/2025
  Reading time: 10:00
  Reading place: ETSAB (Escola Tècnica Superior d'Arquitectura de Barcelona) - Planta Baixa - Sala de GrausAv. Diagonal, 649-651 - 08028 - Barcelona
  Thesis director: CALLÍS FREIXAS, EDUARD | MONTEYS ROIG, FCO JAVIER
  Thesis abstract: The objective of this research is the study of the collection comprising the 950 architectural exhibitions held in Barcelona from the end of the Spanish Civil War to the present day. The study focuses on the «what» rather than the «how», that is, on their content beyond their display. The most common way architectural exhibitions have been studied is through their individuality or, in some cases, in small associations, but never through the entirety of their exhibition activity. However, in this dissertation, the exhibitions are understood as a whole, as an architectural collection that allows for establishing a series of relationships among them, revealing qualities that can only be uncovered through «the whole». Nor have they been considered from the plurality of the city that hosts them, despite their temporal concurrence and their dispersion across numerous locations in the city, whereas here they are taken as a body equivalent to the architecture of the city to which they belong and simultaneously help to shape.Somewhere between theory and practice, architectural exhibitions serve as a platform for the dissemination and debate of ideas; they are part of and contribute to the architectural discourse of the city in which they are held. This is achieved by conveying a specific argument that stimulates architectural thinking through its content. Such content is composed of a selection of «pieces» usually taken from architectural collections or archives, generally housed in specialized institutions, as well as some elements produced ad hoc. In other words, the collections and archives from which this content is drawn represent an invaluable reserve for the «construction» of new exhibitions. The group of exhibitions that forms the body of study for this thesis is itself a collection, comprising 950 archives. Based on the above, this collection can be seen as a tool for the formation of new arguments and, therefore, new architectural discourses.This research will dissect the exhibitions held in Barcelona from the perspective of the collection, extracting knowledge from both their morphology as exhibition act and the content of their discourse in relation to the city. This body of study will also allow for the revelation of characteristics of architectural exhibitions as an architectural practice in themselves, which, as a recent field of study, remain unexplored. Additionally, with the aim of highlighting the propositional role of architectural archives and collections and «learning to handle» the one addressed here, it will discuss reference case studies through which it will be demonstrated that the collection under study can be taken as an active and usable resource, stemming from the propositional idea intrinsic to all architectural projects. Through this research, it will be shown that this collection of exhibitions, in addition to having the capacity to reveal previously unknown issues that can only be evidenced through its collective condition, is not a passive repository of architectural elements but a latent gathering of ideas awaiting activation. It is a project tool capable of generating potential arguments that open new perspectives on the ongoing transformation of our built environment and its exhibitions.
  
• RODRIGUEZ CALVET DE MAGALHÃES, JOSÉ EDUARDO: Alfred Grenander. Transitional spaces and the mobility infrastructure of Berlin from 1914 to 1930
  
  Author: RODRIGUEZ CALVET DE MAGALHÃES, JOSÉ EDUARDO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN ARCHITECTURAL DESIGN
  Department: Department of Architectural Design (PA)
  Mode: Normal
  Deposit date: 07/04/2025
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: FERRER FORES, JAIME JOSE
  Thesis abstract: The city of Berlin owes the design of most of its subway stations to the Swedish architect Alfred Grenander, who was the main responsible for this task in the beginning of the 20th century. These subway stations, which can be seen as a ‘specialized building type', contributed to the transformations in the urban fabric progressively shifting the urban connections, at the same time that they provided a specific architectural language, through the creation of transitional spaces and incremental spatial solutions. However, despite the relevance of Grenander’s work in the development of the mobility infrastructure in Berlin, there is a lack of systematic research data in a critical spatial analysis of the stations he designed in the interwar period and the techniques applied on the first modal stations of the city of Berlin. Therefore, this research is structured to provide historical, architectural, and theoretical-critical analyses of the design work of the Swedish architect Alfred Grenander, more concretely the subway stations for the city of Berlin, designed between 1914 and 1930. This timeframe allows to understand the transformations that affected the city urban planning and architecture for the modern period. The research assesses the formal and spatial language in the buildings' interior-exterior with the scenarios and traces left from buildings occupation. Ultimately, the aim is to analyze the transitional spaces in their capacity of transformation and ability to generate or adapt to the city urban tissue.To this end, the research project applies a case study approach on two levels. The first one is a historiographical representation – ‘light’ case studies – corresponding to a systematic documentation an overview of sixty-seven stations designed by Alfred Grenander. The second level is a more comprehensive one and corresponds to an 'in-depth' case study analysis with three morphological region-sectors that comprise a total of five stations, inserted in the city infrastructure. In line with this, the research considers typo-morphological analysis and architecture spatial analysis to develop a thesis on transitional spaces according to the urban and architectural and urban design decisions that affected the definition of the building, in a broader notion of the word ‘station’. The political decisions from the Weimar Republic period and social debates and actions give form to a conceptual basis for this analysis. Therefore, the research builds on the premises for the urban morphology methodologies developed by Conzen (1960), Cannigia and Maffei (1979) and spatial analyses by Vieira de Almeida (1968) and Colin Rowe and Robert Slutsky (1963). The epistemological framework applied to this research follows also a hermeneutic and phenomenological approach, to uncover the different meanings and perspectives from the collected data. Architecture analysis is done in a complex structure of settings from the city cultural production between individuals and its socio-historical context needed to comprehend the momentum of Berlin cultural landscape.
  

DOCTORAL DEGREE IN ARCHITECTURAL, CIVIL AND URBAN HERITAGE AND REFURBISHMENT OF EXISTING BUILDINGS

• GORDILLO BEL, DIDAC: De la caponera al búnquer. Evolució de la fortificació des de mitjans del segle XIX a mitjans del segle XX a Catalunya.
  
  Author: GORDILLO BEL, DIDAC
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN ARCHITECTURAL, CIVIL AND URBAN HERITAGE AND REFURBISHMENT OF EXISTING BUILDINGS
  Department: Departamento de Representación Arquitectónica (RA)
  Mode: Normal
  Deposit date: 28/03/2025
  Reading date: 06/06/2025
  Reading time: 11:00
  Reading place: ETSAB (Escola Tècnica Superior d'Arquitectura de Barcelona) - Planta Baixa - Aula C-B4Av. Diagonal, 649-651 - 08028 - Barcelona
  Thesis director: ONECHA PEREZ, ANA BELEN | SÁNCHEZ RIERA, ALBERTO
  Thesis abstract: The thesis is composed, apart from the general introduction, of four interconnected chapters but which could be independent. The first is an overview of the evolution of fortification from antiquity to the middle of the 20th century. The second is the development of fortification in defensive enclosures since the middle of the 19th century, taking into account the curtains and bastions that gradually became low until they became covered caponiers, bastions that in principle are small forts that are part of a set but which could be independent in isolated forts, with crenellated galleries, embrasures with artillery pieces or plans protected only by parapets to place cannons to fire uncovered, and at the back of everything the tower divided into floors where the slingshots are located with the pieces to shoot at a long distance, both in slingshots under cover and pieces located on parapet at the highest point. Tortosa is taken as an excuse, because its case can be extrapolated to others in Catalonia. The fourth part is the realization of the bunker figure. There are enough cases here because unfortunately Catalonia, like the rest of the State, suffered a civil war. In this part, you can see how the bunkers were foreseen and how they gradually materialized with normalizing models that already came from before. Finally, the last part is the concrete explanation of the evolution of the bunker caponera and how it has become more and more camouflaged and more armored as the destructive power of the weaponry increases, how the traditional fortification has disappeared .
  

DOCTORAL DEGREE IN AUTOMATIC CONTROL, ROBOTICS AND VISION

• DELMAS, GINGER: Linking Human Poses With Natural Language
  
  Author: DELMAS, GINGER
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN AUTOMATIC CONTROL, ROBOTICS AND VISION
  Department: Institute of Robotics and Industrial Informatics (IRI)
  Mode: Normal
  Deposit date: 10/03/2025
  Reading date: 23/05/2025
  Reading time: 10:00
  Reading place: Sala d'Actes, Facultat de Matemàtiques i Estadística, Universitat Politècnica de Catalunya (FME), Carrer de Pau Gargallo, 14, 08028 Barcelona
  Thesis director: MORENO NOGUER, FRANCESC D'ASSIS | WEINZAEPFEL, PHILIPPE
  Thesis abstract: Human pose is key to multiple human-centric applications, in a wide range of domains such as art (person depiction), sport (fitness coaching), robotics (skill teaching), entertainment (motion capture in movies, digital animation) or digitization (avatar design). In order to materialize such systems, researchers have designed deep learning models which address the related, underlying tasks of pose-guided image synthesis, 3D human pose estimation, human motion generation, mesh synthesis, pose prior production, and so forth.Until very recently, human pose had mostly been studied in conjunction with images. The field twitched with the arrival of efficient language models, which fostered the incorporation of linguistic in vision frameworks, and thereby powered multi-modal applications.This thesis fits into this dynamic. We aim to leverage Natural Language (NL) to bud human pose understanding in human-centric tasks. In contrast to prior endeavors, we juggle with static 3D human poses, images and detailed NL texts all together. We further explore novel multi-modal applications, requiring fine-grained understanding of the human pose.First, to alleviate the lack of data, we introduce new datasets linking 3D human poses with NL texts. We notably investigate two settings. One where the text is a description of the target pose, and another where the text provides modification instructions to reach the target pose from a source pose. These datasets result both from (i) the collection of crowd-sourced annotations, and (ii) the automatic, rule-based generation of texts, which consists in the incorporation of classified pose measurements into templates sentences. Next, we use these datasets to develop several cross-modal generation models like text-driven pose synthesis, pose captioning, text-guided pose editing and generation of textual posture feedback. Eventually, we connect 3D, text and images through a novel combinating framework, so as to derive a versatile, multi-modal pose representation, to be leveraged for downstream tasks akin to pose estimation or NL posture feedback from visual input.In summary, we tackle multiple machine learning tasks entailing human pose understanding, thanks to the connection of human pose and Natural Language.
  
• TIAN, YI: Bio-inspired Event-driven Intelligence for Motion Estimation
  
  Author: TIAN, YI
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN AUTOMATIC CONTROL, ROBOTICS AND VISION
  Department: Institute of Robotics and Industrial Informatics (IRI)
  Mode: Normal
  Deposit date: 18/03/2025
  Reading date: 19/05/2025
  Reading time: 11:00
  Reading place: Sala d'Actes de la Facultat de Matemàtiques i Estadística (FME), Campus Diagonal Sud, Carrer de Pau Gargallo, 14, 08028 Barcelona
  Thesis director: ANDRADE CETTO, JUAN
  Thesis abstract: Motion estimation problems can range from low degrees of freedom (DOF) ego-motion estimation to complex, high-DOF motion, which includes dense pixel displacement or optical flow. This information is essential for enabling robots to perceive and navigate their environments. However, existing vision systems for motion estimation are less robust and efficient than biological systems, largely due to limitations in sensor technology and processing methods. This thesis builds on the bio-inspired sensor -event camera-, and the brain-inspired computing approach -Spiking Neural Networks (SNNs)-, presenting a promising solution that bridges these gaps. Event-based cameras have high temporal resolution, low latency, reduced data redundancy, and are power efficient. These unique capabilities make them particularly well-suited for environments and tasks where traditional frame-based cameras struggle. They show great potential for the solution of motion estimation problems across a wide range of applications, such as providing accurate and low-latency motion estimation for autonomous vehicles or aerial robots. SNNs are inspired by how neurons in the human brain communicate through synapses using spikes, which are brief and discrete electrical signals that allow highly efficient and robust information processing. The thesis begins with estimating 3-DOF ego-motion, progresses to sparse optical flow, and ultimately tackles dense optical flow. In the first step, the thesis addresses event-based ego-motion estimation by integrating SNN approaches with traditional optimization-based techniques. It explores the ego-motion estimation problem from inference optical flow obtained by an SNN and proposes a pooling method to address the aperture problem encountered in the sparse and noisy normal flow output of the SNN. In the next step, modern artificial neural network (ANN) architectures are leveraged to improve event-based optical flow estimation. This step proposes a U-Net transformer-based architecture with a recurrent neural network as the backbone. In the final phase of this research, the visual transformer architecture is further extended to flow encoders, incorporating spatiotemporal attention to enhance the extraction of temporal information. This led to the development of a swin transformer-based ANN model and its spiking counterpart. Notably, this work marks the first use of spikeformers in event-based optical flow estimation, demonstrating the potential of combining transformer architectures with SNNs for regression tasks. Overall, this thesis advances the understanding of motion estimation using event cameras. It sets the stage for their application in real-world scenarios such as high-speed object tracking and simultaneous localization and mapping (SLAM). The biologically inspired methods developed in this thesis offer promising avenues for balancing the performance and efficiency of computer vision and robotics systems, paving the way for future innovations in this field.
  

DOCTORAL DEGREE IN BIOMEDICAL ENGINEERING

• DAVIS ORTIZ, ALBERTO: Development of a Fuzzy Logic-Based Algorithm for Stroke Detection in Non-Contrast Computed Tomography Images
  
  Author: DAVIS ORTIZ, ALBERTO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN BIOMEDICAL ENGINEERING
  Department: Department of Automatic Control (ESAII)
  Mode: Normal
  Deposit date: 18/02/2025
  Reading date: 09/05/2025
  Reading time: 16:30
  Reading place: Aula 28.8, 1a planta, Edifici I, Escola Tècnica Superior d'Enginyeria Industrial de Barcelona, Campus Diagonal Sud, Av. Diagonal, 64708028 Barcelona
  Thesis director: AYMERICH MARTINEZ, FRANCISCO JAVIER | GORDILLO CASTILLO, NELLY
  Thesis abstract: The present work addresses the problem of early stroke detection, not only from the perspective of detection accuracy, but also focusing on computational efficiency, considering the limited availability of cases for training. To this end, several algorithms have been developed to optimize different processes, such as a brain extraction algorithm, an affine transform algorithm, and a specific adaptive filter for noise in computed tomography images. This research has generated valuable resources, such as a brain atlas of healthy Mexican patients and a template of vascular territories. The use of atlases allowed the extraction of features from specific areas. The features used were relatively simple, such as histograms and Haralick textures, which were combined with linear discriminant analysis and an adaptive neuro-fuzzy inference system as a second layer of feature extraction, and finally with a support vector machine as a classifier. Together, these methods achieved a performance of 98.25%. The results show that using the adaptive neuro-fuzzy inference system as a feature extractor improves the performance of other classifiers due to its ability to handle uncertainty and identify nonlinear relationships between variables. This study contributes to the development of low computational cost algorithms and provides new perspectives and tools that could be applied in a real environment in the future
  

DOCTORAL DEGREE IN CHEMICAL PROCESS ENGINEERING

• AGRELO LESTÓN, ASIER: Development of metal-enhanced TiO2-based photocatalysts for hydrogen production
  
  Author: AGRELO LESTÓN, ASIER
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN CHEMICAL PROCESS ENGINEERING
  Department: Department of Chemical Engineering (EQ)
  Mode: Normal
  Deposit date: 02/04/2025
  Reading date: 02/06/2025
  Reading time: 11:00
  Reading place: Campus Diagonal Besòs, Edifici I (EEBE)Sala Polivalent, Edifici I - I.01Av. Eduard Maristany, 16 08019 Barcelonahttps://eebe.upc.edu/ca/lescola/com
  Thesis director: LLORCA PIQUE, JORDI | SOLER TURU, LLUIS
  Thesis abstract: Human activity has led to rising greenhouse gas levels, altering climate patterns and intensifying weather events. Therefore, a transition to a decarbonized energy system is needed, with hydrogen as a promising energy vector alongside solar and wind energy. However, current hydrogen production methods, such as steam methane reforming, generate significant CO2 emissions. Sunlight-driven water splitting offers a sustainable alternative, though efficiency improvements are required for industrial viability.This PhD thesis focuses on developing novel TiO₂-based catalysts for photocatalytic hydrogen production.Chapter 3 was conducted with the SYMAC team from Université Toulouse 3-Paul Sabatier. A TiO₂ catalyst was decorated with Cu nanoparticles stabilized by quinidine and compared to a sample prepared via incipient wetness impregnation (IWI) using L-ascorbic acid. The quinidine-stabilized sample exhibited 5 times superior activity under UV, as well as activity enhancement under Uv-visible irradiation. UV-vis spectroscopy revealed a plasmonic band relative to Cu, and a decrease in the bandgap was confirmed by Tauc plots. XRD confirmed Cu deposition and predominant anatase phase of the TiO2. TEM confirmed presence of Cu nanoparticles that XAS and XPS identified predominant metallic nature with minor oxide contributions.Chapter 4 was carried out with the Supra- and Nanostructured Systems group at Universitat de Barcelona (UB). Hybrid TiO₂ photocatalysts were prepared with Au(I) complexes and Au(0) systems were developed as co-catalysts. Three catalyst series incorporating coumarin-based ligands were evaluated under light and heat. Two (1 wt.% co-catalyst) were prepared via IWI and ball milling (BM), while a third (0.25 wt.% Au) was synthesized by IWI. IWI-prepared samples showed superior activity, achieving up to 2.7 times the H₂ production of conventional Au/TiO₂. UV-vis spectroscopy confirmed plasmonic bands relatives to Au and Tauc plots revealed bandgap narrowing. TEM, HAADF-STEM, and XPS confirmed the presence of Au nanoparticles with a predominant metallic nature.Chapter 5 focused on Pt/TiO₂ photocatalysts synthesized by BM, optimized through a design of experiments (DoE) approach. The most active sample was 1.4 times more efficient than an IWI-prepared Pt/TiO2 reference under UV light irradiation. HAADF-STEM-EDX revealed Pt atoms dispersed on TiO₂, with post-reaction growth into nanoparticles while there was presence of some Pt atoms dispersed. XPS confirmed partial Pt reduction during the reaction.Chapter 6 explored bimetallic PdCu photocatalysts with a total metal loading of 1 wt.%. A Pd:Cu atomic ratio of 1:2 was chosen after a screening from 3:1 to 1:3. The bimetallic sample outperformed theoretical activity of the combination of thus metals under UV light by 27%, and Cu incorporation enhanced H₂ production under UV-vis irradiation. BM-prepared samples were 1.2 times more active than IWI ones. Pd stability was improved with Cu incorporation, as seen in long-term tests, with less activity loss compared to monometallic Pd. Raman spectroscopy indicated strong metal-support interactions. UV-vis spectroscopy and Tauc plots showed enhanced visible absorption and bandgap narrowing, respectively. HAADF-STEM-EDX revealed bimetallic PdCu nanoparticles in BM samples, whereas IWI samples had separate Pd and Cu nanoparticles. BM also constrained Pd growth, as Pd nanoparticles in the monometallic sample grew 3.5 times during the reaction. XPS showed Pd reduction in both samples, with complete reduction in BM-prepared catalysts, further supported by H₂-TPR.
  

DOCTORAL DEGREE IN CIVIL ENGINEERING

• SETIEN UGALDE, IÑAKI: Enhanced Inherent Strain Modelling for Powder-Based Metal Additive Manufacturing
  
  Author: SETIEN UGALDE, IÑAKI
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN CIVIL ENGINEERING
  Department: Barcelona School of Civil Engineering (ETSECCPB)
  Mode: Article-based thesis
  Deposit date: 10/04/2025
  Reading date: 05/06/2025
  Reading time: 11:00
  Reading place: UPC Campus Nord, ETSECCPBC/ Jordi Girona 1-3edificio C1, Sala 002Barcelona https://meet.google.com/nvd-fqgp-gsc
  Thesis director: CHIUMENTI, MICHELE | SAN SEBASTIÁN ORMAZABAL, MARÍA
  Thesis abstract: Metal additive manufacturing (MAM), particularly powder bed fusion using a laser beam (PBF-LB), has transformed manufacturing by enabling the production of intricate and optimised metal components directly from digital designs. This process offers major advantages such as material efficiency, high geometric flexibility, and the ability to produce lightweight, customised parts. However, its industrial adoption is hindered by challenges such as large residual stresses and distortions resulting from steep temperature gradients and rapid thermal cycles inherent in layer-by-layer manufacturing process. These issues compromise dimensional accuracy and structural integrity, posing barriers to the broader implementation of the technology.High-fidelity thermo-mechanical finite element (FE) simulations can predict these phenomena but their high computational cost makes them impractical for large-scale industrial applications. The inherent strain method (ISM) has emerged as an efficient alternative, condensing complex thermal and mechanical phenomena into an inherent strain tensor applied in simplified elastic simulations. While ISM significantly reduces computational time, conventional implementations often lack robustness, requiring extensive recalibration for different geometries and scanning strategies and failing to capture spatial and temporal variations in thermal histories.This thesis addresses these limitations by developing an enhanced inherent strain method (EISM) for powder bed fusion (PBF), improving ISM's predictive accuracy and extending its applicability to complex industrial geometries. By integrating a macro-scale thermal analysis into ISM, the method dynamically refines the precomputed inherent strain tensor based on part-scale temperature evolution. This enhancement better accounts for geometry- and boundary-specific thermal effects, improving distortion predictions compared to conventional ISM.Additionally, this work tackles the fundamental challenge of determining inherent strain tensors necessary for ISM-based methodologies. Two complementary approaches are proposed: (1) an empirical calibration strategy using twin-cantilever beam coupons, where distortions measured after partial cutting are used to determine best-fit inherent strain tensors via inverse engineering, and (2) a numerical approach employing a meso-scale thermo-mechanical model within a multi-scale framework, computing local inherent strains and homogenising them to obtain macro-scale inherent strain tensors.Comprehensive experimental calibration and validation were conducted using Ti-6Al-4V components manufactured via PBF-LB. Temperature histories were recorded with embedded thermocouples, while distortion and residual stress data were acquired using coordinate measuring machines (CMM), 3D scanning, and incremental hole-drilling, respectively. The empirical and numerical methodologies for inherent strain tensor determination, along with EISM, were validated across multiple geometries, including twin-cantilever beams, a non-symmetric bridge, and an industrial aerospace component (the Steady Blowing Actuator). The results demonstrated that EISM significantly improved distortion predictions while maintaining computational efficiency, reducing errors by more than half compared to conventional ISM.In conclusion, this thesis presents two methods for calculating the inherent strain tensor (empirical and numerical) and introduces the EISM methodology for distortion prediction, improving the accuracy of distortion prediction in PBF-LB. In this way, the dependence on trial-and-error-based experimental testing is reduced, moving towards an optimised simulation-based design and facilitating the industrial adoption of MAM.
  
• , DUOLAN: Integration of Spatial and Temporal Patterns for ecological environment management in River-Riparian System
  
  Author: , DUOLAN
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN CIVIL ENGINEERING
  Department: Barcelona School of Civil Engineering (ETSECCPB)
  Mode: Article-based thesis
  Deposit date: 18/03/2025
  Reading date: 14/05/2025
  Reading time: 12:00
  Reading place: ETSECCPBC/Jordi Girona 1-3, edificio C2Sala de Conferencias (2ª planta)Barcelona
  Thesis director: BLADE CASTELLET, ERNEST | SANCHEZ JUNY, MARTI
  Thesis abstract: Rivers are important carriers of water resources and important components of ecosystems. In some areas, rivers have been artificially narrowed, riparian areas have been encroached upon, riparian resources have been over-exploited, and artificial restrictions have been placed on the river channel. This resulted in the loss of the river's role in receiving and storing flood waters, which leading to the collapse of river banks and the destruction of river embankments, severely affecting the stability of the river, threatening the safety of bridges, culverts and other critical river-related infrastructure, and endangering the ecological environment. The definition of riparian zones is particularly important for the management and protection of rivers. In the implementation of policies to promote river management in various countries, emphasis has been placed on strengthening the management of riparian zones, ensuring the safety of flood control and giving full play to the comprehensive ecological benefits of rivers. In recent years, various countries have proposed laws and regulations in recent years mainly to control overdevelopment, restore natural vegetation growth in riparian areas, protect habitats and achieve flood control. With the progress of water-related social development, the balance between environmental impact and benefits is increasingly emphasized. Changes in river shape, man-made riverbeds, and riverbank construction affect aquatic life and destroy wildlife habitats. River regulation also alters ecosystems. To reduce these impacts, government agencies implement protocols for riparian assessment and monitoring, including physical habitat, hydromorphological, and hydrological regime evaluations.The research first begins with a retrospective analysis as the starting point to acquire how existing laws and regulations on development and restoration lack effective integration and induce weak adaptability. A river-riparian model is developed based on two-dimensional hydraulic modelling integrated with numerical modelling by relying on topographical, hydrological, vegetation, and soil data to analyze the hydro-ecological cycle within the riparian zone and delineate the boundary of riparian. The model aims to provide a site-specific approach to riparian zone delineation. In addition, a system of parameters for ecological status assessment is proposed which focuses on the main contradictions between the environment conservation and the ecosystem services of riparian zones. In order to develop and analyze strategies for a good ecological status of the water bodies and riparian zones, the methodology of riparian zone delineation will provide tools for enhancing the coordination of the needs of riparian resource development and ecosystem protection and use, and the ecological environment assessment system will evaluate the hydromorphological quality and promote the healthy development of the ecological environment. The findings of this research propose a convenient and effective method for delineating riparian zones which can be basically universally applied. It is noteworthy for its applicability in riparian zone management practices and as a reference for policy strategy development. The proposed quantitative evaluation method covers the key aspects of hydromorphological quality evaluation. This eliminates the highly subjective assignment of weights and classification of evaluation levels while also avoiding the inclusion of complex calculation procedures. The river-riparian areas evaluation method allows the decision-makers to easily analyze the problems through the resulting calculations and lay the foundation for further solutions.
  

DOCTORAL DEGREE IN COMPUTER ARCHITECTURE

• LAUT TURÓN, SERGI: Architecture-aware Sparse Patterns to Accelerate Inverse Preconditioning
  
  Author: LAUT TURÓN, SERGI
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN COMPUTER ARCHITECTURE
  Department: Department of Computer Architecture (DAC)
  Mode: Normal
  Deposit date: 10/04/2025
  Reading date: 08/05/2025
  Reading time: pending
  Reading place: pending
  Thesis director: CASAS GUIX, MARC | BORRELL POL, RICARD
  Thesis abstract: This work focuses on improving the efficiency of iterative methods for solving large and sparse linear systems.These problems arise in many fields, including climate modeling, molecular and fluid dynamics, among others.To solve them, iterative methods such as the Conjugate Gradient (CG) and Generalized Minimal Residual (GMRES) methods are widely employed.Their efficiency heavily depends on the choice of preconditioners, which accelerate convergence by improving the numerical properties of the system.Sparse Approximate Inverse (SAI) preconditioners, and their factorized variant (FSAI) for symmetric positive definite systems, are particularly appealing due to their parallel-friendly nature and straightforward application via Sparse Matrix-Vector (SpMV) operations.State-of-the-art SAI and FSAI approaches define their sparsity patterns primarily based on numerical considerations.This work introduces novel architecture-aware preconditioners designed to enhance performance by optimizing the sparse pattern selection process.The first contribution presents the Factorized Sparse Approximate Inverse with Pattern Extension (FSAIE) preconditioner, an optimized version of FSAI tailored for shared memory CPU architectures.FSAIE introduces a cache-aware algorithm that extends sparsity patterns, improving both the numerical effectiveness of FSAI and its computational efficiency.Additionally, a filtering-out strategy is proposed to remove numerically insignificant entries, reducing computational cost without compromising convergence.These techniques enhance data locality in the SpMV kernel by ensuring that extended sparse patterns align with cache-line-sized memory access patterns.The second contribution extends FSAIE to distributed memory CPU environments, introducing the Communication-aware Factorized Sparse Approximate Inverse with Pattern Extension (FSAIE-Comm) preconditioner.FSAIE-Comm incorporates communication-awareness to ensure that the sparse pattern extension does not introduce unnecessary inter-process communication overhead.To prevent load imbalance, an innovative strategy is developed to distribute computational workload more evenly.The third contribution focuses on GPU execution by introducing the GPU-aware Factorized Sparse Approximate Inverse (GFSAI) preconditioner.By structuring the sparse pattern to enhance coalesced memory accesses and exploit GPU-specific architectural characteristics, GFSAI significantly accelerates FSAI computations on GPUs.The final contribution generalizes the architecture-aware preconditioning strategies beyond FSAI by introducing the Communication-aware Sparse Approximate Inverse with Pattern Extension (SAIE-Comm) preconditioner.This approach optimizes SAI for distributed memory environments, similar to FSAIE-Comm, but is adapted for general linear systems where the GMRES solver is preferable over CG.SAIE-Comm highlights the versatility and flexibility of the proposed optimizations, demonstrating that architecture- and communication-aware pattern extensions can be effectively integrated into different preconditioning strategies and solver frameworks.By integrating hardware-aware considerations into preconditioner design, this research advances the state of the art in iterative solvers and contributes to the development of scalable and high-performance numerical methods.The proposed methods achieve substantial improvements in time-to-solution across diverse High-Performance Computing (HPC) architectures, with reductions ranging from 12.94% to 26.43% on five different CPU architectures—Intel Skylake, Power9, Zen 2, A64FX, and Intel Sapphire Rapids—and from 23.83% to 26.07% on two GPU architectures—Volta and Vega20—when applied to representative sparse matrix benchmarks.These results underscore the impact of architecture-aware preconditioning strategies in modern HPC applications, paving the way for more efficient and scalable iterative solvers.
  
• PUJOL TORRAMORELL, ROGER: Improving Real-Time Guarantees of Cache Coherence and Advanced Interconnections in Real-Time Systems
  
  Author: PUJOL TORRAMORELL, ROGER
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN COMPUTER ARCHITECTURE
  Department: Department of Computer Architecture (DAC)
  Mode: Normal
  Deposit date: 18/03/2025
  Reading date: 09/05/2025
  Reading time: 10:00
  Reading place: Sala C6-E101 (Edificio C6)
  Thesis director: CAZORLA ALMEIDA, FRANCISCO JAVIER | ABELLA FERRER, JAIME
  Thesis abstract: The dissertation, research on enhancing timing predictability and performance for Critical Real-Time Embedded Systems (CRTES), focusing on Multi-Processor Systems on Chip (MPSoCs). CRTES are essential in critical domains like automotive and avionics, where complex functionalities and high performance are increasingly required for operations such as AI and multi-sensor data processing. However, MPSoCs face significant timing verification and validation (V&V) challenges, especially related to shared resources like caches and interconnects, which can introduce unpredictable delays. This thesis addresses three core areas to improve CRTES predictability: cache coherence, interconnection predictability, and application performance through vector extensions.Cache Coherence: In MPSoCs, cache coherence protocols ensure consistent data across multiple cores, but shared caches introduce contention that affects timing predictability. Traditional approaches to improving coherence often involve modifying protocols, a costly and complex task. This thesis takes an alternative approach by leveraging hardware event monitors (HEMs) to observe cache contention, providing valuable data for timing V&V without altering existing protocols. This methodology is applied to commercial MPSoCs like the NXP T1040 and T2080, which are widely used in real-time domains.On another note, the Remote Protocol-Contention Tracking (RPCT) method is proposed, which enables fine-grained tracking of delays due to inter-core contention, offering insights into cache coherence impacts on software predictability and informing developers on optimization strategies. Additionally, the thesis proposes a novel Multiple HEM Validation (MHV) method to improve the accuracy of contention measurements by validating HEM reliability through inter-HEM relationships, mitigating known issues with single-event HEM inaccuracies.Interconnections: MPSoCs rely on point-to-point (P2P) communication protocols like AXI4 for data transfer between cores, but the standard AXI protocol lacks timing constraints, making it unpredictable under real-time requirements. Addressing this, this thesis introduces AXI4 Real-Time (AXI4RT), an extension to the AXI protocol that specifies timing parameters to control the duration of transactions between manager and subordinate interfaces. By defining timing guarantees directly within the protocol, AXI4RT ensures predictable communication, enhancing system reliability for real-time applications. Additionally, this thesis provides some initial steps for contention tracking on modern AXI5 interconnects by doing an in-depth analysis how can contention be tracked with currently available HEMs and proposing some HEMs that could improve this tracking.Application Performance with Vector Extensions: To meet growing performance demands in CRTES, MPSoCs often use GPUs and custom accelerators, but these present certification challenges due to their complexity and unpredictable timing. This thesis explores using vector extensions (VExt) as an alternative. Single Instruction Multiple Data (SIMD) processing units are already available in many embedded processors, which perform parallel operations on multiple data elements, effectively improving data processing speeds. Unlike GPUs, VExt are integrated within processors and comply with high-integrity system standards, making them easier to certify. The thesis provides an analysis of VExt in COTS processors like NVIDIA’s AGX Xavier and show their potential to enhance performance while maintaining compliance with standards such as MISRA-C.In summary, this thesis advances the state-of-the-art in CRTES predictability, presenting solutions that ensure more reliable timing for complex embedded systems in safety-critical applications. By addressing cache coherence, interconnect timing, and performance, this thesis provides tools and methodologies for better timing analysis, enabling MPSoCs to improve real-time guarantees.
  
• SEYGHALY, RASOOL: A Federated Learning Approach to Smart Advertising
  
  Author: SEYGHALY, RASOOL
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN COMPUTER ARCHITECTURE
  Department: Department of Computer Architecture (DAC)
  Mode: Normal
  Deposit date: 17/03/2025
  Reading date: 12/06/2025
  Reading time: 10:00
  Reading place: Sala VGE205 - NEÀPOLIS Building
  Thesis director: GARCÍA ALMIÑANA, JORDI | MASIP BRUIN, XAVIER
  Thesis abstract: This thesis presents a Federated Learning-based Smart Advertising System designed to enhance user engagement, optimize network efficiency, and ensure data privacy in digital advertising. Traditional advertising systems face significant challenges in balancing personalization with privacy, managing network overhead, and scaling efficiently. This study addresses these issues by integrating Edge Computing and Federated Learning (FL) to enable real-time, decentralized ad targeting while keeping user data secure.The proposed system consists of a decentralized recommendation engine, where local models are trained on users’ devices and aggregated using meta-heuristic optimization techniques, particularly the Whale Optimization Algorithm (WOA). Experimental results demonstrate that WOA outperforms other aggregation techniques, such as the Firefly Algorithm (FA) and Bat Algorithm (BA), in terms of convergence speed and overall efficiency. The system also leverages formal verification techniques, including model checking, to ensure correctness, security, and compliance with privacy regulations.Comprehensive evaluation through both simulated and real-world case studies (such as the AROUND system) shows that the proposed architecture reduces network traffic, minimizes computational overhead, and significantly improves Click-Through Rates (CTR) and user engagement compared to traditional centralized models. The system is particularly beneficial for applications in museums, shopping malls, and retail chains, providing real-time tracking, indoor mapping, and personalized content delivery.The findings underscore the potential of Federated Learning and Edge Computing in privacy-preserving smart advertising, offering a scalable, cost-efficient, and user-centric solution for the future of digital marketing.
  

DOCTORAL DEGREE IN COMPUTING

• FLORES HERRERA, JAVIER DE JESÚS: A Framework to Operationalize and Automate the Data Integration Lifecycle
  
  Author: FLORES HERRERA, JAVIER DE JESÚS
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN COMPUTING
  Department: Department of Computer Science (CS)
  Mode: Normal
  Deposit date: 14/04/2025
  Reading date: 12/05/2025
  Reading time: pending
  Reading place: pending
  Thesis director: ROMERO MORAL, OSCAR | NADAL FRANCESCH, SERGI
  Thesis abstract: Data plays a key role in today’s world. Many organizations collect and store massive amounts of data from many different data sources. As a result, these data collections show a diversity in structure and semantics that grows as the data sources expand and evolve. These factors challenge traditional data management methods, which depend on fixed structures and stable conditions. There is a mismatch between old assumptions and new realities, where it is not enough to just collect data and run conventional tools. Instead, we must rethink how we integrate data to support high variety, handle large-scale collections, and accommodate new available data. This PhD thesis proposes innovative and advanced techniques to support and automate the data integration lifecycle. First, we describe how to represent and standardize data sources using graph-based schemas. These schemas provide a solid foundation for all steps of the data integration lifecycle. Next, we introduce an integration method that leverages graph-based schemas to add new data incrementally without disrupting existing integration structures. This approach ensures that data integration remains flexible and scalable as organizations grow. We also help users find the right datasets to integrate. By focusing on data discovery, we reduce the time spent exploring irrelevant data sources and suggest relevant ones for integration. To this end, we focus first on facilitating the discovery of joinable attributes among datasets. We propose a new qualitative metric and use data profiles and learning models to decide which attributes are worth joining. To further enhance data discovery, we introduce contextual pre-filtering. Using data profiles and graph-based schemas, we can focus on promising datasets before applying data discovery tools. This pre-filtering step not only boosts the accuracy of existing data discovery tools but also optimizes their performance by narrowing the search space. In summary, this thesis helps bridge the gap between conventional data methods and modern, diverse data ecosystems. The results contribute to the field of data integration by offering scalable and automated solutions that match the changing needs of data integration today.
  

DOCTORAL DEGREE IN CONSTRUCTION ENGINEERING

• RAMONELL CAZADOR, CARLOS: Graph-driven digital twins as assistants to bridge maintenance
  
  Author: RAMONELL CAZADOR, CARLOS
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN CONSTRUCTION ENGINEERING
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Normal
  Deposit date: 10/03/2025
  Reading date: 28/05/2025
  Reading time: 10:00
  Reading place: C1-002
  Thesis director: CHACÓN FLORES, ROLANDO ANTONIO
  Thesis abstract: Bridges are vital components of transport infrastructure networks which are facing a widespread lack of resilience due to aging and changing environmental conditions. Finding more efficient methods for monitoring bridge networks and effectively planning their maintenance is crucial for maintaining reasonable serviceability levels. Simultaneously, digital twins are emerging across industries as dynamic digital replicas of physical assets. These are continuously updated with information from their physical counterparts and serve as the foundation for digital tools that enhance workflows in decision-making processes throughout the lifecycle of any product.This dissertation translates the concept of digital twins to the bridge maintenance domain and presents a framework for developing graph-driven digital twin systems to assist bridge managers in tracking the state of their asset portfolio.For this purpose, two different proof-of-concept systems are presented: System A and System B. Both systems are cloud-based, modular, and use graphs to integrate multiple data sources describing the bridges, their context, and relevant maintenance information. The systems are tested with real data corresponding to two demonstration cases of road and railway bridges in the Spanish infrastructure network. Through these demonstrators, the digital twin systems are developed to integrate BIM, GIS, sensor time-series data, and data related to the results of monitoring processes that is structured according to regional standards.System A focuses on hosting digital twins of individual bridges. It uses a labelled property graph (LPG) to interconnect IFC data with IoT sensor data and the results from visual inspections and load tests. Data integration is achieved by matching GUIDs of data contained the graph with data stored in the different databases and systems connected. The implementation of the system is demonstrated through a web-based digital twin platform, containing applications that allow visualizing and interacting with contextualized inspection and load test data.System B focuses on interconnecting multiple bridge digital twins within the same network. It employs a knowledge graph built from Resource Description Framework (RDF)-based graphs and a set of ontologies. The system integrates geographical data according to INSPIRE data models, IFC models, and data from visual inspections. The system presents a data management approach based on strata, which manage and compartmentalize information subsets, and implements the information containers for linked document delivery (ICDD) standard for exchanging graph data with linked documents. The system is demonstrated through a set of fictitious scenarios that simulate interactions between bridge administrators and third parties.Through these systems, this dissertation demonstrates the usefulness of graph technologies in developing digital twins of bridges that are aligned with current industry standards and practices. It emphasizes the advantages of the Knowledge Graph-based approach for simplifying interactions with connected applications, enabling decoupled application development, and enhancing the system scalability and expandability with new datasets. Notwithstanding, real implementation of these systems requires further validation and use cases, as well as collaboration among system developers, administrators, academia, and industry stakeholders to generate a coherent digital ecosystem that enhances the efficiency and productivity of bridge maintenance practices.
  

DOCTORAL DEGREE IN EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS

• RODRÍGUEZ SÁNCHEZ, JULIO: Nonlinear Identification of Underground Seismic Ground Motions From Surface Records
  
  Author: RODRÍGUEZ SÁNCHEZ, JULIO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Normal
  Deposit date: 19/12/2024
  Reading date: 08/05/2025
  Reading time: 16:00
  Reading place: ETSECCPB.UPC, Campus NordBuilding C1. Classroom: 002C/Jordi Girona, 1-308034 Barcelona
  Thesis director: LOPEZ ALMANSA, FRANCISCO | LEDESMA VILLALBA, ALBERTO
  Committee:
       PRESIDENT NO PRESENCIAL: BENAVENT CLIMENT, AMADEO
       SECRETARI: VARGAS ALZATE, YEUDY FELIPE
       VOCAL NO PRESENCIAL: PINZÓN, LUIS ALEJANDRO
  Thesis abstract: In earthquake engineering, generally only surface records are available; therefore, the motion of the lower soil layers must be estimated by depropagation analysis. Underground accelerograms are relevant in earthquake-resistant design of structures with buried parts, in irregular terrain, in earthquake-triggered landslides, and in soil-structure interaction, among other situations. These considerations highlight the relevance of the problem analyzed; regarding its mathematical formulation, if the soil behavior is nonlinear, it is far from trivial.The common practice in Earthquake Engineering consists of using a deconvolution process for obtention of ground motion at the base of the numerical model used for seismic analysis of underground structures. The drawback of this method is that, as it is carried out in the frequency domain, it cannot simulate the variation of the nonlinear characteristics of the soil during seismic excitation, but it hypothesizes that the mechanical properties of the soil are invariant for its whole duration. This leads to inaccurate calculation of excitation at lower soil layers that are especially acute when the soil column is weak or earthquakes are strong.This thesis presents an algorithm to accurately estimate, from surface records, the motion of the lower soil layers considering nonlinearity in soil nonlinear behavior by a modified Masing model. The proposed algorithm is 1D and the soil domain to be analyzed is discretized in layers; the ensuing equations of motion are solved in discrete time using the Newmark method. Given that this problem is numerically ill-conditioned due to the singularity of the mass matrix, a nonlinear Bayesian Kalman Filter-type method is used to estimate the solution.Soil propagation software is developed in Python programming language, incorporating state-of-the-art considerations about numerical simulation of soil behavior under seismic loading. This program is tested against closed-form solution for vibration of soil columns and site response analysis conducted using the widely used DEEPSOIL program to check its accuracy in computation of soil profile behavior under seismic conditions with satisfactory results.Then, the soil propagation software is coupled with the Unscented Kalman Filter algorithm to identify the input excitation at bedrock given the acceleration record at site surface. Several variations of this Bayesian filter are explored. Results of identification from both closed-form solutions for vibration of soil columns and site response analysis carried out with DEEPSOIL suggest that the proposed back-analysis algorithm for the obtention of acceleration time series at bedrock given surficial measurements is accurate, especially when compared to the deconvolution procedure.Finally, a sample underground structure modeled in PLAXIS2D is subjected to two ground motions at base: one is a deconvolved motion and the other is a depropagated accelerogram obtained through the identification process developed in this research. Difference in resulting structural forces from both records highlights the importance of adopting nonlinear algorithms for determination of input excitation at base for an adequate and safe design of underground structures.
  

DOCTORAL DEGREE IN ELECTRICAL ENGINEERING

• AL HANAINEH, WAEL HASAN AHMAD: Designing and Development of Secure Protection Strategies for Distribution Network Integrated with Distributed Energy Resources
  
  Author: AL HANAINEH, WAEL HASAN AHMAD
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN ELECTRICAL ENGINEERING
  Department: Department of Electrical Engineering (DEE)
  Mode: Article-based thesis
  Deposit date: 10/03/2025
  Reading date: 16/05/2025
  Reading time: 12:00
  Reading place: Aula A2.07, Edifici A de l'EEBE
  Thesis director: MATAS ALCALA, JOSE | GUERRERO ZAPATA, JOSEP MARIA
  Thesis abstract: Global electricity generation increasingly incorporates Distributed Generation (DG) resources, such as solar and wind, into distribution systems (DS), offering benefits like improved reliability, power quality, rapid integration, and reduced payback periods, while lowering greenhouse gas emissions. However, their integration presents challenges, including overvoltage, voltage fluctuations, and imbalances caused by improper synchronization with the grid. DGs alter short-circuit currents, necessitating updates to protection relay settings. As DG penetration rises, distribution networks become more complex, requiring advanced protection systems to handle bidirectional power flows, which challenge existing schemes. Inverter-based DGs, such as solar and wind, generate lower fault currents due to inverter power electronics, diminishing the effectiveness of traditional fault detection methods, leading to potential protection blinding or false tripping. These challenges highlight the need for precise fault detection, accurate localization, and rapid protective responses. Disconnecting DGs during faults is increasingly undesirable, requiring innovative protection schemes to minimize unnecessary disconnections and address limitations like fault resistance, pre-fault load conditions, and noise interference. Traditional fault location techniques, often computationally intensive, struggle with accuracy, prolonging restoration times and increasing downtime, further emphasizing the need for advanced fault protection systems. Total Harmonic Distortion (THD) analysis has proven effective for fault detection in systems with complex harmonic profiles caused by DG integration. Faults induce increased harmonic distortion, making THD monitoring a valuable indicator. Despite its promise, protection systems for grids with high DG penetration, especially those using inverter-based DGs, are underexplored, and existing protection algorithms rarely incorporate THD. To address this, three novel protection systems utilizing grid voltage harmonic content for fault detection and localization in medium-voltage (MV) DS are proposed. The first system combines THD measurements with voltage amplitude and zero-sequence components using a finite state machine (FSM)-based algorithm. It focuses on third harmonic (triple-n) components, unique to inverter neutral points and unaffected by other grid harmonics. Fault-induced voltage dips excite harmonic components, amplifying THD, making it an effective fault indicator. THD is calculated using the Multiple Second Order Generalized Integrator (MSOGI) method. However, this system relies on communication channels, which could fail, limiting its robustness. To mitigate this, a two-layered protection system is introduced. The first layer employs the SOGI-FLL grid monitoring technique, optimizing computational efficiency by reducing the number of required SOGIs while maintaining accurate THD calculations. Fault detection is achieved by filtering the THD signal and comparing pre-fault and fault-time averages, with significant deviations indicating faults. The second layer implements a communication-less fault localization algorithm based on positive and negative voltage sequence components to determine fault symmetry. This approach enables each protection device (PD) to operate independently, ensuring reliable fault localization even without communication, albeit with slightly slower detection times compared to communication-based methods. To enhance overall reliability, especially during communication failures, a third system, priority system, is proposed. It integrates the two-layered protection, with the first layer as the primary fault detection and communication-based trip signal initiator. If communication fails, the second layer provides backup protection by analyzing voltage sequence components locally. The effectiveness of these systems is validated against different protection method under various conditions.
  
• GADELHA TEIXEIRA FILHO, VINICIUS: Conceptualization, Design and Optimal Operation of Hybrid AC-DC Power Router Grids
  
  Author: GADELHA TEIXEIRA FILHO, VINICIUS
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN ELECTRICAL ENGINEERING
  Department: Department of Electrical Engineering (DEE)
  Mode: Normal
  Deposit date: 10/04/2025
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: SUMPER, ANDREAS | BULLICH MASSAGUÉ, EDUARD
  Thesis abstract: Driven by increasingly strict climate goals, the need for modernization of the electric power system has intensified in recent years. The transition towards a distributed and decarbonized smart energy system requires modernizing power grids to accommodate the widespread adoption of renewable energy sources (RES), electric vehicles (EVs), and distributed energy resources (DERs). One key factor to enable this is the advancements in power electronics and their widespread deployment. The Power Router (PR) technology is crucial for this transition, as it facilitates flexible and efficient management of electricity as well as integration between AC and DC grids. It is a device composed of multiple ports that provides a seamless interface of different elements of a power grid by controlling the power between ports.In the first half of this thesis, different kinds of PR concepts are investigated and a novel grid concept based on PRs has been defined, named Power Router Grid (PRG). The PR concept adopted consists of coupling a set of voltage source converters to a common DC bus, in which each converter functions as a different input or output port. The converter model design used is the Modular-Multilevel-Converter (MMC) and is adaptable for PRs with any number of ports and any power level. Then, the theory behind the PRG is presented. First, a set of rules is proposed to ensure the correct configuration and operation of the PRG. Secondly, each PR role is defined based on their tasks within the PRG. Finally, in combination with graph theory methods, a new concept is introduced called Slack Tree (ST). The ST is the backbone that regulates and ensures power balance and the feasibility of the PRG operation, and is a connection path between all ports operating as a slack element.In the second half, all of these novelty concepts behind the PRG are combined with optimal power flow (OPF) models, convexity techniques and converter loss modelling. The goal is to create a Python-based convex OPF formulation suitable for any hybrid AC-DC network Based on PRs. The mathematical formulation is based on a second-order cone relaxation of the traditional power flows equations applied to radial networks. The developed PRG-OPF however, due to the decoupling characteristics of the PRs, is demonstrated to be suitable for any network meshed through PRs. In the last part of thesis, this formulation is further expanded to include the effects of converter losses. The loss model developed is defined as a set of linear constraints that are scalable and easy to implement inside an OPF. Additionally, other constraints regarding DC lines and AC grid integration are developed and integrated. The proposed OPF formulation is loss-aware and utilizes the full potential of PRs to integrate different systems.Throughout this doctoral thesis, seven case studies are presented in order to demonstrate the validity of the proposed concepts. Specifically, the power flow analysis show the viability of the highly-flexible PRG design. Different sensitivity analysis are conducted in order to assess the impact of converter losses and also the ST selection in the optimal operation of the PRG. Among the key remarks, the results demonstrate that the choice of ST does not significantly affect line losses. It is also shown that, despite the added converter losses, the PRG is more efficient than a traditional network in most scenarios, particularly in the presence of loads with low power factor.
  

DOCTORAL DEGREE IN ELECTRONIC ENGINEERING

• MORADMAND JAZI, HAMED: Design and implementation of lowinterference, high efficiency, power electronicbased power system for PV applications
  
  Author: MORADMAND JAZI, HAMED
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN ELECTRONIC ENGINEERING
  Department: Department of Electronic Engineering (EEL)
  Mode: Normal
  Deposit date: 13/03/2025
  Reading date: 15/05/2025
  Reading time: 11:30
  Reading place: Escola d'enginyeria de Barcelona Est. Edifici A, Aula Polivalent A0.03https://meet.google.com/fty-smyy-fgj
  Thesis director: MARTINEZ GARCIA, HERMINIO | VELASCO QUESADA, GUILLERMO
  Thesis abstract: Nowadays, high step-up converters with fast-dynamic response are demanded for many applications such as uninterruptible power supplies which are used to feed sensitive loads and DC-DC converters in grid connected micro inverters to absorb the maximum power from the PV panels. Several studies have been carried out on high step-up converters to increase voltage gain and efficiency as well as reduce the voltage stress of semiconductors while less attention has been paid to their dynamic response. A converter which can compensate load variations rapidly would have faster dynamic response and lower undershoot and overshoot output voltage and current. In this research, various switching converters will be investigated to achieve new topologies having the capability of faster dynamic response and obtaining higher voltage gain for the above-mentioned applications. Merging some converters has the potential of removing right half plane zero and making converters respond load variations at a faster pace without making any changes in the control circuit and filters. If the integrated converter can deliver power form the input to the load in all operating modes whether the switch is on or not, the converter would compensate load variations with lower interruption. This theory can be evaluated and proved by doing some theoretical and mathematical calculations on the control response and the situation of Zeros and Poles of the closed loop transfer function of the converter. To rate the achievements of this research, the dynamic quantities in the step response of the converters (e. g. overshoot, rise time, and settling time) can be investigated. Also, the voltage gain and efficiency of the converters are important qualities which have to be considered in comparisons. A time table is considered for each stage to ensure that this research can be finished through the next three years.
  

DOCTORAL DEGREE IN ENVIRONMENTAL ENGINEERING

• PASTOR LÓPEZ, EDWARD JAIR: Nature-based solutions to reduce the spread of antibiotics and antimicrobial resistance genes in aquatic ecosystem
  
  Author: PASTOR LÓPEZ, EDWARD JAIR
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN ENVIRONMENTAL ENGINEERING
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Article-based thesis
  Deposit date: 14/04/2025
  Reading date: 12/05/2025
  Reading time: pending
  Reading place: pending
  Thesis director: MATAMOROS MERCADAL, VÍCTOR | ESCOLÀ CASAS, MÒNICA
  Thesis abstract: Antibiotics (ABs) are antimicrobial agents whose production and consumption have increased exponentially since the discovery of penicillin in 1929. The overuse of ABs has driven the emergence of antibiotic resistance, leading the frequent detection of ABs and antimicrobial resistance genes (ARG) in aquatic environments, primarily due to wastewater treatment plants (WWTP) effluent discharge despite regulatory efforts. Additionally, prolonged extreme weather conditions, such as droughts, intensify this issue by reducing water availability, threatening aquatic ecosystems and human health. Although advanced water treatment technologies, such as ozonation or membrane-based systems, can remove these pollutants from wastewater, their high cost of construction and maintenance, limited their widespread implementation. Alternatively, Nature-Based Solutions (NBS) have emerged as a potential option due to their cost-effectiveness and their potential capacity to remove a wide range of pollutants. However, studies on the reduction of ABs and ARGs in full-scale on NBS applied to wastewater treatment or river streams remain limited.This PhD dissertation is presented as a compendium of publications and evaluates the effectiveness of NBS in reducing ABs and ARGs in wastewater. First, a review study explored the capacity of NBS to reduce the presence of ABs, ARGs and pathogens across diverse aquatic environments spanning secondary wastewater treatment to estuarine areas and saltmarshes (Chapter II – DOI: 10.1016/j.scitotenv.2024.174273). Second, the performance of two full-scale configurations of constructed wetlands (CW) as tertiary wastewater treatment systems were monitored during the summer and the winter seasons to assess the reduction of ABs and ARGs (Chapter III – DOI: 10.1016/j.watres.2024.122038). Their effectiveness were compared with a conventional tertiary wastewater treatment technology system. Third, the impact of wastewater effluent-dominated stream renaturalization on the reduction of ABs and ARGs across seasonal variations was assessed by monitoring a vegetated and less vegetated stream during both warm and cold periods (Chapter IV – DOI: 10.1016/j.envres.2025.120910).The findings presented in this doctoral research project demonstrate that NBSs are potential alternatives for water treatment management in river basins. CWs as tertiary wastewater-treatment systems have shown the capacity to improve the general water quality parameters and remove ABs and ARGs. In addition, unlike conventional systems, those systems promote a shift in microbial composition towards a more natural profile and reduce the ecotoxicological and resistance selection risks more than a conventional tertiary WWTP. Furthermore, vegetated streams with meanders have shown to increase the degradation kinetics of ABs and the attenuation of ARGs, foster gradual changes in bacterial community structures and decrease the ecotoxicological and resistance selection risks, especially during the warm period. Further research should keep focusing on evaluating novel full-scale NBS configurations, identification of the transformation products (TPs) as well as other aquatic micropollutants, quantification of diverse ARGs and assessing the ecological status of the water.
  

DOCTORAL DEGREE IN MARINE SCIENCES

• RAYA RODRIGÁLVAREZ, VANESA MARIA: Spatial and temporal dynamics of larval fish communities in relation to environmental variability in the NW Mediterranean
  
  Author: RAYA RODRIGÁLVAREZ, VANESA MARIA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MARINE SCIENCES
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Normal
  Deposit date: 10/03/2025
  Reading date: 15/05/2025
  Reading time: 10:00
  Reading place: ETSECCPBUPC, Campus NordBuilding C1. Room 002.C/Jordi Girona, 1-308034 Barcelona
  Thesis director: SABATÉS FREIJÓ, ANA MARIA
  Thesis abstract: The early developmental stages of fish, eggs and larvae, found in the planktonic environment are subject to a high mortality. Thus, the study of larval survival has been a key issue in fisheries science since the early 20th century. Spatial patterns in the larval fish communities are influenced by a complex array of environmental processes that interacts with fish biology at different temporal and spatial scales. These processes include those of large scale, such as climate patterns and seasonal and interannual environmental variability, which determine adults’ distribution and their spawning strategies. At local and short time scale, larval fish communities are shaped by the hydrodynamics that influence fish larval dispersal and retention, and by biologic factors, such as food concentration and predation, that ultimately determine their survival.This thesis characterises the structure of the larval fish community in summer and winter in the Catalan coast (NW Mediterranean), an area with a wide array of environmental conditions and high hydrodynamic activity. The aim is to understand its spatial and interannual variability in response to changes in environmental conditions, including oceanographic variables and hydrodynamic processes. Within the context of climate change, the thesis describes long-term changes in the structure of the summer larval fish communities and aims to understand the interactions between larvae of established species and species that are expanding northwards in the area.To investigate the influence of winter environmental conditions on the structure of fish larval communities, two winters, 2017 and 2018, with contrasting environmental conditions were compared. 2017 was mild, while 2018 was more severe, with intense vertical mixing and deep-water formation and cascading events that enhanced shelf-slope water exchanges. Differences in the structure of larval fish community were found in relation to shelf-slope water exchange processes.A high spatial heterogeneity in larval fish communities was detected in the summers of 2003, 2004 and 2012, related to environmental factors, such as the continental shelf structure, latitudinal difference in surface temperature, primary productivity, and stratification level. Hydrodynamic structures such as instabilities of the Northern Current and anticyclonic eddies, also played an important role in the configuration of these communities.In summer, over three decades, 1980s, 2000s and 2010s, an increase in sea water temperature and a decrease in chlorophyll were detected. Changes in the composition and abundance of the larval fish community were also detected. These were mainly due to the presence of warm water species in the area for the first time, or to their increase in abundance, in the 2000s in relation to the northward expansion of the adults' range. Other species showed a decline in abundance over time, probably due to the decrease in chlorophyll.This work quantitatively compared the survival chances for larvae of E. encrasicolus (a established species) and S. aurita (a species expanding northwards). To this aim, a new method, the Box-Balance Model, was developed to evaluate the role of hydrodynamic structures in their mortality. The model revealed that despite the warming trend would contribute to the expansion of S. aurita, it has not yet developed an adaptation strategy as successful as that of E. encrasicolus, a well-established species in the area.
  

DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING

• MORENO MARTÍN, SIRO: Collocation methods for the synthesis of graceful robot motions
  
  Author: MORENO MARTÍN, SIRO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MECHANICAL, FLUIDS AND AEROSPACE ENGINEERING
  Department: Department of Mechanical Engineering (EM)
  Mode: Normal
  Deposit date: 10/03/2025
  Reading date: 16/05/2025
  Reading time: 18:00
  Reading place: Sala de Juntes de la FME, UPC
  Thesis director: CELAYA LLOVER, ENRIC | ROS GIRALT, LLUIS
  Thesis abstract: Graceful motion can be loosely defined as the one we observe in natural movements executed by animals and humans, which are characterized by being agile, efficient, and fluid. The generation of graceful robot motions is typically sought through the minimization of cost functions involving not only path length, but also aspects related to smoothness, like the time derivative of acceleration, called jerk, or that of the controls. A widely used approach to compute optimal trajectories is through direct collocation, a technique that converts the continuous-time optimal control problem into a finite-dimensional NLP problem. Collocation proceeds by discretizing the trajectory using so-called collocation points, and imposing the dynamics constraints at such points. The formulation of most collocation methods, however, assumes that the system is governed by a first order ODE, whereas robotic systems are typically described by second or higher order ODEs. As a result, the usual practice is to initially convert those ODEs into first order form via introducing new variables, and adding new equations that link these variables with their integral counterparts. An often overlooked effect of this transformation is that it generates inconsistencies between the trajectory of each variable and that of its time derivative. This is so because a collocation method only imposes the differential relationships at the collocation points, but not in between such points. A closer examination of this effect reveals that the dynamic equations, which should be satisfied in the collocation points, are actually violated in them, despite apparently having been enforced. This thesis introduces new collocation methods designed to overcome these problems. Specifically, we develop improved versions of the most popular piecewise and pseudospectral collocation schemes, including the trapezoidal and Hermite-Simpson methods, as well as the LG, LGR, and LGL methods. The new algorithms are able to treat differential equations of arbitrary order M ≥ 1 without having to convert them into first order form. In all of them, the trajectory obtained for each variable coincides exactly with the time derivative of its corresponding integral variable, and the dynamic constraints are satisfied accurately at the collocation points. These properties allow a drastic reduction of the dynamics error of the obtained trajectories in many cases, meaning that the governing equations are better respected along the continuous time horizon of the problem. Our methods also provide trajectories that are smoother than those of conventional ones, and easily treat variables such as jerk or the time derivative of the controls in the cost function. An hp adaptive refinement algorithm is also proposed to combine the benefits of our piecewise and pseudospectral methods so as to speed up convergence to the solutions.
  

DOCTORAL DEGREE IN NUCLEAR AND IONISING RADIATION ENGINEERING

• MARTÍN GIL, KEVIN: Thermal-hydraulic Scaling Distortions in Pressurized Water Reactors
  
  Author: MARTÍN GIL, KEVIN
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN NUCLEAR AND IONISING RADIATION ENGINEERING
  Department: Department of Physics (FIS)
  Mode: Normal
  Deposit date: 10/04/2025
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: FREIXA TERRADAS, JORDI | MARTÍNEZ QUIROGA, VÍCTOR MANUEL
  Thesis abstract: Ensuring safety in Nuclear Power Plants (NPPs) requires a deep understanding of their phenomenology, in the context of the deterministic safety assessment. Scaling plays a key role in this understanding, as it is necessary to downscale the complex thermal-hydraulic systems of NPPs to the scale of Integral Test Facilities (ITFs) for research. Constructing a full-scale NPP for experimental purposes is not economically feasible, making downscaling an essential approach. However, achieving a perfect scale model is impossible, as neither engineering nor scientific designs can fully satisfy all scaling requirements to preserve phenomena across different scales.This thesis investigates scaling distortions in several accident scenarios, including the Intermediate Break Loss-of-Coolant Accident (IBLOCA), Steam Generator Tube Rupture (SGTR), and a Main Steam Line Break (MSLB) in a Pressurized Water Reactor (PWR). The research examines the impact of preserving environmental heat losses and the Froude number in horizontal legs, as preserving the latest is essential for stratification, which influences droplet entrainment and reflooding in LOCA scenarios. Additionally, environmental heat losses play a crucial role in replicating plant energy balance, both of which significantly affect coolant discharge through the break. The study also assesses the effects of two different scaling approaches on heat losses and their associated distortions. Furthermore, this research aims to propose methodologies for quantifying, reducing, and mitigating scaling distortions in these scenarios.In this thesis, the Power-to-Volume Scaling Tool (PVST), which is based on the Power-to-Volume scaling methodology, was modified to automate input and output processing, also allowing for downscaling capabilities. Coupled with pre- and post-processing scripts, this modification enabled automated batch generation of validated hybrid and Scaled nodalizations for RELAP5 at any scale. These nodalizations were then used to simulate all the aforementioned scenarios and post-process the results. The hybrid and scaled nodalizations are based on the OECD/NEA ROSA-2 project in the Large-Scale Test Facility (LSTF). These nodalizations employ multiple scaling rationales, varying the treatment of horizontal legs and heat losses, either preserving or not preserving the Froude number and ideal heat losses.Additionally, a first-of-its-kind Best Estimate Plus Uncertainty Plus Scale (BEPU-PS) methodology-built upon the BEPU GRS method with the added incorporation of scaling considerations-was applied to Test 2. This approach preserved ideal heat losses and the Froude number in horizontal legs to quantify scaling distortions in a wide range of scale and compare them to the inherent uncertainties of the ITF and RELAP5.The main phenomenology of the studied scenarios was analyzed across multiple scales and scaling rationales. In IBLOCA scenarios, scaling distortions were observed when the Froude number was not preserved in horizontal legs and when ideal heat losses were not maintained, leading to variations in Peak Cladding Temperature (PCT) and changes in coolant distribution within the primary system of the PWR hybrid-scaled design. Additionally, scaling rationales that preserved ideal heat losses and the Froude number tended to reduce scaling distortions related to PCT, mass distribution, and the timing of emergency core cooling system injections. The BEPU-PS scales bands, along with Spearman's rank correlation coefficients, revealed that the primary contributors to widening the BEPU bands were the discharge coefficient, the scaling number parameter had a significantly lower statistical relevance according to Spearman's rank correlation coefficients.Regarding SGTR-MSLB scenarios, the study highlighted that SGTR scenarios exhibited no significant scaling distortions when the L/Dh ratio was. Additionally, no evidence of scaling distortions was found in MSLB scenario.
  

DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS

• DOROST, POROCHISTA: Nanoparticles made of poly(gamma-glutamic acid) derivatives for drug delivery systems
  
  Author: DOROST, POROCHISTA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Normal
  Deposit date: 14/03/2025
  Reading date: 10/06/2025
  Reading time: 11:30
  Reading place: Aula de audiovisuales del DEQ en la ETSEIB (Planta G-2)Campus Diagonal Sud, Edifici PIAvda. Diagonal, 64708028 Barcelonahttps://etseib.upc.edu/ca
  Thesis director: GARCIA ALVAREZ, MONTSERRAT
  Thesis abstract: Polymers have become one of the primary options in biomedical fields due to their diverse properties, functionalities, and applications. Characteristics such as mechanical strength, biocompatibility, and biodegradability have made these materials highly attractive for various medical applications. One of the most intriguing applications of these polymers is drug delivery. Biodegradable polymers and copolymers are the primary materials used for producing temporary medical and pharmaceutical devices. These polymers can be chemically synthesized or naturally produced.Biotechnological polymers, produced through biotechnological processes, have garnered significant attention due to two major advantages. First, they are derived from renewable resources; second, as they are biologically produced, they are usually biocompatible, biodegradable and bioresorbable. Therefore, modifying these polymers to tune their properties or functionalities is an effective strategy for developing biomedical materials.Poly(γ-glutamic acid) PGGAH is a biocompatible and biodegradable poly-γ-peptide with carboxylic side groups that can be substituted to modify the polymer’s properties. In this study, PGGAH was hydrophobically and cationically modified. Through hydrophobic modification and altering the hydrophilic properties, amphiphilic copolymers were produced, capable of self-assemble into nanoparticle systems for drug encapsulation and controlled release. This modification was carried out by partial esterification of carboxylate side groups with 4-phehyl-butyl bromide (4-PhBBr). Further decoration to produce stealth and targeting nanoparticles was achieved by reaction of some remaining carboxylate side groups with amino ended poly(ethylene glycol) (NH2-PEG) and NH2PEG derivatized with folic acid, respectively. Cationic modification of this biodegradable polymer enabled the formation of nanopolyplexes with DNA. This modification was carried out by esterification of carboxylate side groups with cationic 2-bromoethyl trimethylammonium bromide (BrETABr). The obtained derivatives were used to prepare nanoparticles through emulsion solvent evaporation or nanoprecipitation dialysis techniques. Nanoparticles with an approximate size of 100 to 380 nm were obtained, demonstrating their potential as drug delivery systems capable of encapsulating the anticancer drug doxorubicin.The chemical structure of the derivatives were characterized using proton and carbon-13 nuclear magnetic resonance (NMR) spectroscopy, and the physicochemical properties by gel permeation chromatography (GPC), and thermal gravimetric analysis (TGA). Functional group analysis was conducted through Fourier-transform infrared spectroscopy (FT-IR). Hydrolytic degradation was monitored by 1H NMR, while the appearance of the nanoparticles was observed using scanning electron microscopy (SEM), and their size and surface charge were determined by dynamic light scattering (DLS) and zeta potential measurements, respectively.For the hydrophobic copolymer series, cytotoxicity assays were carried out, confirming the low toxicity of the synthesized derivatives. Drug encapsulation and release was initially evaluated under physiological conditions, revealing that the release rate was higher in acidic pH and affected by the degree of polymer modification. On the other hand, cellular uptake nanoparticle tests demonstrated that the nanoparticles successfully penetrated cancer cells. The results of this study indicate that the biotechnological polymer PGGAH is a promising material for designing and developing biodegradable drug delivery systems with potential therapeutic applications for challenging diseases in pharmacological treatment.
  

DOCTORAL DEGREE IN STATISTICS AND OPERATIONS RESEARCH

• BLANC BLOCQUEL DI MARCO, AUGUSTO: Derivatives and risks
  
  Author: BLANC BLOCQUEL DI MARCO, AUGUSTO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN STATISTICS AND OPERATIONS RESEARCH
  Department: Department of Statistics and Operations Research (EIO)
  Mode: Normal
  Deposit date: 13/03/2025
  Reading date: 03/06/2025
  Reading time: 11:00
  Reading place: Aula de Teleensenyament, edifici B3, Campus UPC Barcelona Nord
  Thesis director: ORTIZ GRACIA, LUIS
  Thesis abstract: This thesis aims to provide solutions to real world problems by the use and development ofstate-of-the-art quantitative finance techniques. The first part of this work tackles the challenge of digital options hedging, particularly, at the-money digital options near maturity. The problem stems from the fact that a digitaloption has a discontinuous payoff at the strike price and has a huge delta and gamma nearexpiration. This problem is well-known among practitioners and academics. In this work, weconsider a general setting for hedging at-the-money digital options near maturity by meansof a bull spread. We solve different optimization problems, with the aim of minimizing theprobability of sub-hedging the digital option at maturity, considering transaction costs andilliquidity issues. Our contribution consists in the fact that we determine the compositionof the bull spread that minimizes the probability of sub-hedging a digital option given thatthe cost of hedging is below a certain threshold. We consider traditional and state-of-the-artmodels for driving the dynamics of the underlying asset. We also introduce the modelingof the illiquidity issue in the optimization problem, and solve that optimization problem.Finally, we calibrate one model to real market data and solve the optimization problem withtransaction costs with the calibrated model.In the second part of this work we intend to create financial tools to fight against climatechange. Over the last five years there have been increasing concerns about the impact ofcryptocurrency mining on climate. One of the main effects of climate change is its impacton agriculture and food production. In addition, climate change has clear consequencesfor human health. We propose novel bitcoin-denominated derivatives contracts on carbonbonds to address this problematic. This paper creates novel financial products which couldhelp the regulatory authorities impact the climate in an indirect fashion, agglutinating twodesired financial outcomes (hedging and volatility transfer) in a single financial instrument.Particularly, the instrument can be used by governments to hedge against climate change andinfluence the prices of carbon bonds and cryptocurrencies. In order to price this product, wedevelop novel parameter estimation techniques based on Shannon wavelets.The third part of this work also revolves around climate change, finance and mathematics.In this work we put forward a methodology to calculate the impact of an increase of the earth’sglobal surface temperature on the probability of default of a company from the agriculturesector. Extreme temperatures have a negative impact on asset prices in all sectors. Weperform a regression of firm’s stock value with predictors S&P 500 and temperature anomaliesand observe that an increase of temperature anomalies has a negative impact on the stockof the firm considered in this work. When modelling temperature anomalies time series it isimportant to identify points in time where a significant change occurs in the behaviour of thedata. These points are called breakpoints. Then, we model the time series of temperatureanomalies by means of segmented linear regression, where the breakpoints are estimatedby means of a wavelet analysis. We calibrate a Merton model with real stock data of thecompany and estimate the probability of default based on the probability that the assetvalue of the firm is below the liabilities level. We proceed to use the regression model toforecast future values of the firm’s stock influenced by the predicted temperature anomaliesand estimate a new probability of default.
  
• PACHÓN GARCIA, CRISTIAN: Contributions on dimensionality reduction and interpretable machine learning
  
  Author: PACHÓN GARCIA, CRISTIAN
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN STATISTICS AND OPERATIONS RESEARCH
  Department: Department of Statistics and Operations Research (EIO)
  Mode: Normal
  Deposit date: 28/03/2025
  Reading date: 08/05/2025
  Reading time: 10:00
  Reading place: Sala de Juntes de l'FME
  Thesis director: DELICADO USEROS, PEDRO FRANCISCO
  Thesis abstract: This thesis is divided into two parts. The first one is devoted to dimensionality reduction for large data sets, while the second one focuses on the field of Interpretable Machine Learning. Part of the material presented in this thesis has been published either in journals or workshops. Concretely, the original work of Chapter 1 can be found in Delicado and Pachón-García (2024a). Regarding Chapter 3, the original publication is Pachón-García et al. (2024) and the material of Chapter 4 is Hernández-Pérez et al. (2024). Finally, Chapter 5 is intended to be sent to a journal, but Delicado and Pachón-García (2024b) is a preprint version.To begin with, we present a set of algorithms implementing multidimensional scaling (MDS) for large data sets. MDS is a family of dimensionality reduction techniques using a n×n distance matrix as input, where n is the number of individuals, and producing a low dimensional configuration: a n × r matrix with r << n. When n is large, MDS is unaffordable with classical MDS algorithms because their extremely large memory and time requirements. We compare six non-standard algorithms intended to overcome these difficulties. They are based on the central idea of partitioning the data set into small pieces, where classical MDS methods can work. Two of these algorithms are original proposals. In order to check the performance of the algorithms as well as to compare them, we have done a simulation study. In addition, an open-source R package implementing the algorithms has been created.Regarding the field of machine learning (ML), it is worth noting that its presence in our society is increasing, which brings with it the need to understand the behaviour of ML mechanisms, including machine learning predictive algorithms fed with tabular data, text, or images, among other types of data. Therefore, this thesis focuses on the problem of interpretability. On the one hand, we present SurvLIMEpy, an open-source Python package that implements the SurvLIME algorithm. This method allows to compute local feature importance for machine learning algorithms designed for modelling Survival Analysis data. The presented implementation uses a matrix-wise formulation, which allows to speed up the execution time. Additionally, SurvLIMEpy assists the user with visualisation tools to better understand the result of the algorithm. The package supports a wide variety of survival models, from the Cox Proportional Hazards Model to deep learning models such as DeepHit or DeepSurv. We study the ability of the algorithm to capture the importance of the features by means of a simulation study.With the goal of employing SurvLIMEpy, we train and compare three types of machine learning algorithms for Survival Analysis: Random Survival Forest, DeepSurv and DeepHit, using the SEER database to model cutaneous malignant melanoma. Our work underscores the importance of explainability methods for interpreting black-box models and provides insights into important features related to melanoma prognosis.On the other hand, we consider the field of Functional Data Analysis in order to provide it with interpretability tools. Designing interpretability methods for functional data models implies working with a set of features whose size is infinite. In the context of scalar on function regression, we propose an interpretability method based on the Shapley value for continuous games, a mathematical formulation that allows to fairly distribute a global payoff among a continuous set players. The method is illustrated through a set of experiments with simulated and real data sets. The open source Python package ShapleyFDA is also presented.
  

DOCTORAL DEGREE IN SUSTAINABILITY

• LEDUCHOWICZ MUNICIO, ALBA: Multicriteria methodology for assessing the sustainability of last-mile electrification programs
  
  Author: LEDUCHOWICZ MUNICIO, ALBA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SUSTAINABILITY
  Department: University Research Institute for Sustainability Science and Technology (IS.UPC)
  Mode: Article-based thesis
  Deposit date: 14/04/2025
  Reading date: 21/05/2025
  Reading time: 12:00
  Reading place: UPC - ETSEIBSala: Seminari 1 del DOE, Av Diagonal 647, edifici H, planta 7Campus Sud, Barcelona
  Thesis director: DOMÉNECH LÉGA, BRUNO | FERRER MARTI, LAIA
  Thesis abstract: The sustainability-driven global energy transition requires ensuring universal access to electricity, particularly in last-mile rural areas. Renewable-based energy access programs are pivotal for fostering development, empowerment, and climate resilience in these regions. However, comprehensive assessments of past efforts are crucial to avoid repeating mistakes and ensure operational success of these initiatives. Likewise, it is particularly important to consider the durability and impact of the implemented solutions in terms of development and gender equality. This PhD thesis aims to address these gaps by developing multi-criteria procedures for a holistic sustainability assessment of last-mile electrification initiatives in emerging economies, while also extracting lessons from real-world case studies. The research first analyses the local energy transition for two historically marginalized populations: indigenous and traditional communities. It also assesses large-scale electrification programs in Brazil and Venezuela, and subsequently evaluates the operation and region-wide impacts in three Brazilian states. Additionally, a framework using gender data and sex-disaggregated data is proposed to ensure gender-responsive electrification initiatives, with case studies from three Brazilian municipalities. These phases underscore the importance of tailored multicriteria decision-making analysis frameworks that consider local contexts, stakeholder preferences, and inclusive perspectives. Assessment of last-mile electrification outcomes reveals the transformative potential of renewable energy solutions, emphasizing the need for systemic and integrated approaches and multi-stakeholder collaboration to achieve Sustainable Development Goals. This analysis serves as a guide for last-mile electrification promoters to synergistically address sustainable design, operational durability and long-term local development that leaves no one behind.
  

DOCTORAL DEGREE IN THERMAL ENGINEERING

• HOPMAN, JOHANNES AREND: The Checkerboard Problem in Finite Volume Methods: Origins, Solutions, and Applications in Magnetohydrodynamics
  
  Author: HOPMAN, JOHANNES AREND
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN THERMAL ENGINEERING
  Department: Department of Heat Engines (MMT)
  Mode: Normal
  Deposit date: 10/04/2025
  Reading date: 08/05/2025
  Reading time: 11:00
  Reading place: Sala de conferències del TR5, ESIEAAT (Terrassa)
  Thesis director: RIGOLA SERRANO, JOAQUIM | TRIAS MIQUEL, FRANCESC XAVIER
  Thesis abstract: This thesis addresses the checkerboard problem in collocated Finite Volume Methods (FVM) for incompressible flows, a numerical issue caused by the decoupling of neighboring control volumes when using a collocated pressure-velocity coupling. This decoupling results in non-physical, high-frequency oscillations in the pressure field, which affect the accuracy and stability of Computational Fluid Dynamics (CFD) simulations. The research provides a mathematical analysis, a quantification method, and a numerical framework to mitigate the checkerboarding issue. The study is particularly relevant for magnetohydrodynamics (MHD) at low magnetic Reynolds numbers, where numerical stability and conservation laws are critical.The thesis is structured as follows:Chapter 1 introduces CFD and the FVM approach, the motivation for the study, and the challenges in simulating incompressible flows.Chapter 2 explores the mathematical origins of checkerboarding, highlighting how the wide-stencil Laplacian operator and mesh topology contribute to the issue.Chapter 3 introduces a checkerboard coefficient, which allows real-time quantification of the problem. A novel numerical solver is developed, balancing numerical dissipation with checkerboarding effects.Chapter 4 applies the methodology to MHD flows, incorporating a symmetry-preserving framework and testing it on electromagnetic Taylor-Green vortex and turbulent duct flow cases. The results demonstrate improved accuracy, stability, and conservation of current density.Chapter 5 presents conclusions and future research directions, including potential extensions to higher-order schemes and alternative grid arrangements.The key contributions of this work include:A mathematical understanding of checkerboarding in collocated FVM schemes.A quantification method using the checkerboard coefficient, enabling real-time monitoring.A numerical strategy that dynamically adjusts numerical dissipation to control checkerboarding.The application of these methods to MHD simulations, demonstrating their effectiveness in high-fidelity engineering applications.This research is highly relevant for applications involving complex geometries and conservation laws, such as nuclear fusion research (ITER), metallurgical processes, and electromagnetic flow control. The proposed approach enhances numerical stability while maintaining accuracy and conservation properties, laying the groundwork for future advancements in incompressible flow simulations.
  

DOCTORAL DEGREE IN URBAN AND ARCHITECTURAL MANAGEMENT AND VALUATION

• GARCÍA HARO, ALAN: Isla de frío de los parques urbanos: Hacia la definición de parámetros de composición para la optimización del efecto de enfriamiento en distintos contextos climáticos mediante análisis remoto
  
  Author: GARCÍA HARO, ALAN
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN URBAN AND ARCHITECTURAL MANAGEMENT AND VALUATION
  Department: Department of Architectural Technology (TA)
  Mode: Normal
  Deposit date: 02/04/2025
  Reading date: 19/05/2025
  Reading time: 17:30
  Reading place: ETSAB (Esc. Técnica Sup. Arquitectura de Bcn)-Planta Baja-Sala de GradosAv. Diagonal, 649-651-08028-Barcelona(Inicio conexión a les 17:00 h)
  Thesis director: ROCA CLADERA, JOSE NICASIO | ARELLANO RAMOS, BLANCA ESMARAGDA
  Thesis abstract: Due to their composition, generally characterized by the predominant presence of vegetation and permeable soils, urban parks exhibit lower temperatures compared to other areas of the city. In many cases, this thermal reduction extends to the surrounding areas, generating the phenomenon known as the "park’s cool island" (PCI). This effect makes parks essential elements for regulating and mitigating urban heat, a problem exacerbated by the urban heat island effect, the global increase in temperatures, and the growing frequency and intensity of extreme heat events associated with climate change. These situations pose significant threats to public health, disproportionately affecting vulnerable groups and increasing heat-related mortality rates. Moreover, the limited availability of updated and detailed climatic data hinders the planning and design of effective mitigation strategies at the local level.This research aims to establish design parameters that optimize the cool island effect of urban parks (PCI) in various climatic contexts, employing remote sensing techniques. To achieve this, a flexible methodology was developed based on satellite data analysis and statistical models, adaptable to both the availability of information and the specific characteristics of each case study. The methodology is structured into three main stages: 1) quantification of the intensity and spatial extent of the cool island effect generated by parks; 2) estimation of physical descriptors derived from remote sensing data; and 3) statistical analysis of the influence of the physical characteristics of parks and their surroundings on cool island effect indicators.This study focuses on the cases of Barcelona (Mediterranean climate) and Mexicali (hot arid climate), selected for their contrasting climatic conditions and differing levels of institutional data availability. Initial results reveal that in Barcelona, with 86 urban parks, the average daytime summer PCI intensity was 1.51°C with a spatial extent of 78.02 meters, whereas Mexicali, with 435 parks, recorded an intensity of 0.90°C and a spatial extent of 119.03 meters. A notable contrast emerges in these parameters, as two parks in Barcelona showed no cool island effect (2.3%), while in Mexicali, this number increased to 133 parks (30.6%). The results demonstrate that vegetation is the primary regulator of urban temperature in both cities. In Mexicali, explanatory models incorporating variables derived from NDVI and supervised land cover classification using Random Forest achieved R² values exceeding 90% in spring and summer. In Barcelona, although NDVI was also relevant, the analysis highlighted limitations related to proximity to the sea and forested areas.In conclusion, this research establishes a methodological framework to define design parameters for urban parks using remote sensing data, tailored to the functional and temporal needs of each context. This represents a significant step toward developing specific tools for urban planning decision-making, integrating key considerations for regulating and mitigating urban heat.
  
• ZHENG, QIANHUI: Planificación de la adaptación al clima extremo en el contexto del cambio climático. La ciudad esponja como elemento clave para la resiliencia
  
  Author: ZHENG, QIANHUI
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN URBAN AND ARCHITECTURAL MANAGEMENT AND VALUATION
  Department: Department of Architectural Technology (TA)
  Mode: Article-based thesis
  Deposit date: 07/04/2025
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: ROCA CLADERA, JOSE NICASIO | ARELLANO RAMOS, BLANCA ESMARAGDA
  Thesis abstract: Climate change represents an unprecedented challenge for Mediterranean coastal regions, especially for Spain. This doctoral thesis, focused on climate change and its impact on regional extreme events, through systematic and multidimensional scientific research, reveals the complex mechanisms of climate change and its profound effects on ecosystems and urban environments.In the first part of the research, the thesis proposes an innovative method for estimating nocturnal surface temperature. By combining satellite imagery and multiple regression techniques, the study reveals significant characteristics of the urban heat island effect, especially during nighttime. This method not only improves the understanding of urban microclimate but also provides important scientific foundations for urban thermal stress response strategies.Regarding climate classification, the thesis systematically optimizes the existing climate classification system in Spain. The research introduced more geographical and climatic variables and used advanced statistical techniques, such as K-means clustering and spatial regression, significantly improving current building technical standards. The new classification method more accurately reflects the climatic diversity of Spain, providing a more detailed framework for assessing building energy efficiency.Based on high-resolution data from 1971-2022, the study systematically analyzes Spain's climate trends. The research discovered a significant warming trend, especially in maximum temperatures. Simultaneously, notable changes in precipitation patterns were observed, characterized by an overall decrease in precipitation but with an increase in the frequency and intensity of extreme precipitation events. Projections indicate that by 2050, Spain could face a crucial transition towards a semi-arid climate.In flood risk assessment, the study developed an innovative multicriteria evaluation method. Through comprehensive analysis of topographical, hydrological, and land cover factors, the research created detailed flood risk maps, with special emphasis on vulnerable Mediterranean coastal regions. Notably, the reconstruction of the significant flood event in the Valencian Community in 2024, using high-resolution precipitation data and advanced hydrodynamic models, precisely simulated the event's spatio-temporal evolution.Finally, taking the El Poblenou neighborhood in Barcelona as a case study, the thesis systematically evaluated the effectiveness of "sponge city" strategies in mitigating urban flood disasters. The study demonstrated the significant potential of technical innovations such as permeable pavements, rain gardens, and green roofs in reducing urban flood risks, providing a robust practical approach to urban climate adaptation.The research employed an innovative multi-method approach, integrating remote sensing technologies, statistical modeling, geographic information systems, and hydrodynamic analysis. The study not only expands the boundaries of climate change science but also provides scientifically feasible paths for building more resilient and sustainable urban systems.The research results highlight the urgency of implementing mitigation and adaptation measures, especially for Mediterranean coastal regions. Future research will further optimize climate models, improve flood risk assessment methods, and expand the application of "sponge city" strategies.
  

DOCTORAL DEGREE IN URBANISM

• COLAUTTI, VIVIANA ELIZABETH: El orden desconcertado. Tensión entre soporte físico y cuadrícula. Lógicas de ocupación en la ciudad de Córdoba, Argentina.
  
  Author: COLAUTTI, VIVIANA ELIZABETH
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN URBANISM
  Department: Department of Urbanism, Territory and Landscape (DUTP)
  Mode: Normal
  Deposit date: 10/04/2025
  Reading date: 08/05/2025
  Reading time: pending
  Reading place: pending
  Thesis director: SABATE BEL, JOAQUIN | MOISSET DE ESPANES, INES
  Thesis abstract: This research was born with the firm conviction that the growth and transformation of the city of Córdoba (Argentina) result from a unique dialogue and a complementary relationship between the physical support (that includes topography, rivers, streams, railway lines linked to contour lines) and the geometric order of the grid. These tensions develop in a very particular Latin American historical context that has shaped the city.The transformations of urban growth mainly stem from industrial-productive use (railway) and are located on the edges of natural elements (such as the Suquía river, or the La Cañada stream), or between pericentral neighborhoods. In these neighborhoods, located around its central area, the city shows very diverse grids, marked by unique physical features.The complex order of the city arises from the meeting point of three distinct orders. The abstract order of the grid, the order of the physical support and the temporal historical component. This encounter produces a disconcerting order, characterized by accelerated changes, the coexistence of heterogeneous elements and the loss of memory in undefined and interstitial areas. These areas, located next to clearly ordered areas, are the remnants of the city and cause inequalities in the use of space and strong contrasts in the urban fabric.Our main objective is to detect the occupation logic during the urban transformation processes that result from the tension between the physical support and the grid.The processes of urban growth have determined both the productive destiny of the city of Córdoba and its identity. It is the merging between a geographical dimension and a geometric one, where the growth of the grid triggers the transformation processes. This urbanization process reveals an occupation strategy that involves the transformation of the natural environment into a built environment.The concept of order, understood as an instrument of organization and an articulator between various urban components, has faced tensions all throughout the history of our Latin American cities. Such tensions derive from pre-existing elements and practices, thus shedding light on a permanent counterpoint between order and disorder. The main contribution of this thesis is to reveal the transformation processes that influenced the changes in the city. We/I seek to detect the logic behind growth and the categorization at various scales of urban interstices of the pericentral neighborhoods of Córdoba.The main hypothesis is that the order of the grid, political in origin and related to the subdivision and distribution of the land, adapts to various situations and particular intersections, while simultaneously faces the definite and physical facts of the city; in contrast to the order of the physical support, that transformsg according to the technological advances of the city and that includes the geographical, topographical, geological and structural location of the city in itself. These orders are linked by temporal historical events, giving rise to unique urban forms that reflect local logics of occupation and production, consequently emphasizing the interaction of factors and the convergence of orders that shape urban growth.We propose three methodological stages: critique, inquiry and synthesis. In the critique stage, we characterize the study area, develop questions, and define the study components (physical support and grid). In the inquiry stage, our starting point is the bibliographic and cartographic analysis of the city of Córdoba and the reading and interpretation of drawings, maps, images and data of reality and we seek to perform a process of layered reading with a certain level of abstraction. We use a set of interpretive graphics to detect permanent and emerging elements in urban transformations. In the synthesis stage, we propose a series of possible interpretation instruments.