Public display of deposited theses
Presentació d'al·legacions a una tesi doctoral en el termini d'exposició pública
In accordance with the Academic Regulations for Doctoral Studies, doctors may request access to a doctoral thesis in deposit for consultation and, if there are, to send to the Permanent Commission of the Doctoral School the observations and allegations that they consider opportune on the content.
DOCTORAL DEGREE IN AEROSPACE SCIENCE AND TECHNOLOGY
- SKOROBOGATOV, GEORGY: Optimizing workspace division for multi-UAV systemsAuthor: SKOROBOGATOV, GEORGY
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 AEROSPACE SCIENCE AND TECHNOLOGY
Department: Department of Physics (FIS)
Mode: Normal
Deposit date: 20/09/2023
Deposit END date: 04/10/2023
Thesis director: BARRADO MUXI, CRISTINA | SALAMI SAN JUAN, ESTHER
Committee:
PRESIDENT: COLOMINA FOSCH, ISMAEL
SECRETARI: PASTOR LLORENS, ENRIQUE
VOCAL: DELAHAYE, DANIEL
Thesis abstract: With the advance of UAV-related technology using several drones in the context of a single mission becomes more and more common. New problems and challenges appear as a result.When analyzing research works on using systems of multiple UAVs we could notice that the majority of the authors provided few details on how the path planning or workspace division was done. Out of those researchers who mentioned it, some pointed out that the planning or area partitioning was performed by hand. Other researchers presented brief ideas of algorithms with too little information to implement it. In other research works very brief lists of algorithms were given that could solve the problem. And even in those cases when the information on the algorithms was provided, the algorithms themselves did not have any freely available implementations.The purpose of this thesis is to fill the gap in the area of workspace division in order to facilitate the usage of systems consisting of multiple UAVs. In order to accomplish the aforementioned goal, in this thesis, we performed analysis of the literature on the subject of workspace decomposition between multiple robots and UAVs in particular.As it will be shown later, there are almost no research works published in this area. We implemented two state of the art algorithms and shared information on how we achieved that and what were the aspects that needed clarification or could be improved. We analyzed thoroughly the produced results, and propose improvements to the algorithm that yielded better results. And finally, we proposed, implemented, and analyzed two alternative algorithms based on the obtained experience. These algorithms outperformed the algorithm from the literature in terms of quality of the resulting partition. One algorithm solves the partition problem for convex polygons and the other one solves the partition problem for non-convex polygons. Finally, we have summarized a set of open problems that could be solved in future.
DOCTORAL DEGREE IN BUSINESS ADMINISTRATION AND MANAGEMENT
- AGUILAR VILLAJOS, JAVIER: Desarrollo de competencias de Inteligencia Emocional (IE) en el perfil profesional de la Ingeniería CivilAuthor: AGUILAR VILLAJOS, JAVIER
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 BUSINESS ADMINISTRATION AND MANAGEMENT
Department: Department of Management (OE)
Mode: Normal
Deposit date: 20/09/2023
Deposit END date: 04/10/2023
Thesis director: PONS PEREGORT, OLGA
Committee:
PRESIDENT: GASCÓ GASCÓ, JOSE LUIS
SECRETARI: SUNYER TORRENTS, ALBERT
VOCAL: GONZALEZ RAMIREZ, Mª DE LOS REYES
Thesis abstract: This research project is to discuss. contrast and demonstrate the need to influence the training and development of emotional intelligence competences in the civil engineering profile. as well as to propase a model for the assimilation and integration of competences within the framework of management functions and to analyse the relationship between the emotional intelligence of civil engineers in Spain and their leve! of professional satisfaction.Based on documentary research and semi-structured interviews with civil engineering professionals. the emotional intelligence competencies are identified and grouped according to the dimensions of Golemans model (1998). Subsequently. a questionnaire adapted from Bar-On's (1997) measurement instrument, the "Emotional Quotient lnventory" (EQ-i). is developed.The scope of the study focused on civil engineering professionals who are members of the association of civil engineers and technical engineers of public works throughout Spain.The methodological approach was quantitative and exploratory, with descriptive and correlational analyses. with surveys of 220 civil engineers. The main results show that there is a positive and significant relationship between emotional intelligence and professional satisfaction of the respondents, and that there are significant differences in their professional satisfaction according to the years of experience.Based on both the bibliographical study and the results obtained in the questionnaires. the relevance of El competences for the development of Civil Engineering is sustained. both for the people who practise it and for the organisations where they work and the social systems they impact with their work.
DOCTORAL DEGREE IN CIVIL ENGINEERING
- AIASH, AHMAD: Urban Mobility Safety in Barcelona: An evaluation of risk factors and techniques to achieve Vision ZeroAuthor: AIASH, 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 CIVIL ENGINEERING
Department: (DECA)
Mode: Article-based thesis
Deposit date: 20/09/2023
Deposit END date: 04/10/2023
Thesis director: ROBUSTÉ ANTÓN, FRANCESC
Committee:
PRESIDENT: STUDER, LUCA
SECRETARI: MARTÍNEZ DÍAZ, MARGARITA
VOCAL: PÉREZ ZURIAGA, ANA MARÍA
Thesis abstract: In order to converge towards Vision Zero concept in road safety, traffic crashes need great study and analysis. This thesis is aimed at this goal, applied to the urban and metropolitan environment of Barcelona. The thesis is organized as a compendium of eight papers, each dealing with a specific safety risk factor. We use different techniques according to the objectives and data: traditional statistical models, time series analysis, and machine learning techniques. Random Utility Models such as Binary Probit Model, Chi-square Automatic Interaction Detector, Bayesian networks such as Tree Augmented Naïve tree, and Kohonen clustering. The methodology is generic and can be extrapolated to other cities, regions/countries, and datasets. When searching for risk factors of severe or fatal injuries, with the data of 47,153 traffic accidents that occurred in Barcelona between 2016 and 2019, we found the worst injured odds for males and 65 years (and older) persons, pedestrians and drivers (higher probabilities compared to passengers), weekends, afternoon, and night timings. Working hours timing and season (summer) have also influence in the number of severe crashes. During the COVID-19 pandemic, all levels of injuries that resulted from traffic crashes have shown approximately 39% (slight), 30% (severe), and 36% (fatal) injuries reduction. City areas surrounded by higher noise levels, may lead to more traffic crashes as a potential distraction factor, but further research is needed (noise and traffic levels are correlated). Barcelona had a total population of 1,636,762 inhabitants in 2019, distributed on 10 districts. Eixample (literally, ¿broadening¿ of the city, planned by civil engineer Ildefons Cerdà in 1856), which is the district that has the highest population, highest usage of private transport mode, and highest density of passenger cars/km2 compared to all other districts, has the highest risk of having all types of injuries resulting from traffic crashes.Elderly pedestrians are more likely to have severe or fatal injuries, especially during the morning period. When evaluating bicycle lanes and stations safety, the most vulnerable age category for cycling is 26 to 50 years old people during morning and evening timing. Of course, bicycle lanes and bicycle stations in zones that have a restricted speed limit of 30 km/h, showed a lower crash injury ratio. Finally, motorcycle crash injuries have worrying high values in Barcelona, a motorcycle-city. Alcoholism and pavement in poor condition can indeed increase the probability of having different levels of injuries. Young motorcyclists (25-40 years old) have higher odds for crash injuries, unlike elderly users who are less likely to be involved in motorcycle crashes. After analyzing all these factors in detail with the proper methodologies and available data, this document concludes with recommendations and future research lines.
- LARRIVA VILLARREAL, HERNÁN: SEDIMENTACIÓN FINA Y CORRIENTES DE TURBIEDAD EN EMBALSES. CASO DE ESTUDIO: EMBALSE AMALUZA (ECUADOR)Author: LARRIVA VILLARREAL, HERNÁN
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: (DECA)
Mode: Normal
Deposit date: 13/09/2023
Deposit END date: 27/09/2023
Thesis director: SANCHEZ JUNY, MARTI
Committee:
PRESIDENT: PUERTAS AGUDO, JERÓNIMO
SECRETARI: BLADE CASTELLET, ERNEST
VOCAL NO PRESENCIAL: BERMÚDEZ PITA, MARÍA
Thesis abstract: Turbidity currents in reservoirs are of strong scientific interest because they can be responsible for the contribution of large amounts of fine sediments that can cause early sediment filling. The case study corresponds to the Amaluza reservoir in Ecuador of 120 Hm3 and which generates 1100 MW, this reservoir is considered one of the most important about the country.This study is presented in three main blocks. Initially, the fundamental conceptual aspects of turbidity currents and their numerical modeling are characterized. The following aspects about this are described: the hydrodynamics of turbidity currents, the main types of numerical models used to simulate delta displacements and turbidity currents, as well as specific aspects of the modeling and theoretical considerations about shear stress on the bed ¿b.The case study of the Amaluza reservoir in Ecuador is described in the following section of this doctoral thesis. Its fluvial forms are characterized and the available field information that allows the analysis of its morphodynamic behavior is described (fluvial forms, delta formation and delta displacement, etc.).The study continues by fine-tuning the hydrodynamic model of the Amaluza reservoir, proceeding to its calibration, initially without considering sediment transport, so the computational model is built with its respective structured mesh considering its aspect ratio, mesh orthogonality, mesh smoothness and the appropriate ¿t time step is determined. It is modeled under three scenarios: a uniform steady state, a non-uniform steady state, and a non-uniform and non-steady state. In these three scenarios, the velocities and shear stresses on the bed ¿b are calculated in the most relevant areas of the Amaluza reservoir. Once the model has been calibrated, it is ready for the next stage of sedimentological modeling. Thus, the main sedimentological parameters are established; this information will serve as the starting point for the computational model. Thus, are determined the grain size scale, the fall velocity in still water (ws,0), the suspended sediment size, the final fall velocity of particles (ws) and flocculation, its bulk density, and the calculation of the critical shear stress (¿cr) for weakly consolidated thinbeds in agreement with soil mechanical perspective.Finally, the turbidity current is simulated and calibrated for a measured event in 1984 for different scenarios and bathymetries, obtaining the concentration profiles and the main hydraulic parameters of the turbidity current. Once this simulation has been adjusted, the turbidity current removal efficiencies were analyzed under different scenarios (opening of bottom drains, load intakes, etc.).
DOCTORAL DEGREE IN COMPUTATIONAL AND APPLIED PHYSICS
- YUAN, MINGYUE: Historical copper and iron coloured glazes and glassesAuthor: YUAN, MINGYUE
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 COMPUTATIONAL AND APPLIED PHYSICS
Department: Department of Applied Physics (FA)
Mode: Normal
Deposit date: 18/09/2023
Deposit END date: 02/10/2023
Thesis director: PRADELL CARA, TRINITAT
Committee:
PRESIDENT: GARCIA ARANDA, MIGUEL ANGEL
SECRETARI: MOLERA I MARIMÓN, JUDIT
VOCAL: VILARIGUES, MARCIA
Thesis abstract: Coloured glazes and glasses have attracted human interest since antiquity for their aesthetic appeal and multiple functionalities. Asindicators of technological progress, artistic expression, and social stratification in different historical periods, copper and iron haveemerged as the predominant colourants in historic glazes and glasses, offering a remarkable spectrum of hues influenced byvarying contents, ratios, and atmospheric conditions in their production. In order to explore the intricacies of copper red formation, toaddress the limited research on iron yellow in high-lead glazes, and to understand the interaction of both cations in glaze colour, weinvestigated four representative cases, high-lead imperial iron yellow glazes from the Ming (1368-1644) and Qing (1616-1912)dynasties, North Song (960-1127) dynasty copper and iron blue and red Jun ware glazes, late Tang (9th-10th century) dynastycopper green and red Changsha ware glazes, and 13th to the 20th century European copper red window glasses. Using acomplementary set of analytical techniques, including ultraviolet-visible-near infrared (UV-VIS-NIR) spectroscopy, optical microscopy(OM), scanning electron microscopy (SEM), electron microprobe analysis (EMPA), laser ablation inductively coupled plasma massspectrometry (LA-ICP-MS), micro X-ray diffraction (µ-XRD) and X-ray absorption fine structure (XAFS), we investigated the opticalproperties, micro/nanostructures, glaze and glass compositions, valence state, and coordination structures. Our results revealeddistinct variations in glaze and body composition for the high-lead yellow glazes of the Ming and Qing dynasties, while demonstratingthe influence of factors such as glaze thickness, firing temperature, substrate composition, and firing atmosphere on glaze colour.The study of Jun ware glazes elucidated the glass nanostructure and the oxidation-reduction dynamics of iron and copper,explaining the sky-like appearance of the glazes. Similarly, our study of Changsha ware glazes revealed the role of phase separationand copper oxidation state in glaze opacity and colour, and the influence of sulphur in the formation of copper nanoparticles. Finally,our study of European red window glass identified three distinct technologies, highlighting the role of copper nanoparticles in the redcolouring and the role of iron, sulphur and tin in copper reduction. In summary, this comprehensive investigation has improved ourunderstanding of the colouring mechanisms and compositional differences in historic glazes and glasses, and provides valuableinsights into ancient glassmaking technologies.Key words: Historical glaze; Red window glass; Iron; Copper; Sulphur; Tin; XAFS; Micro-XRD
DOCTORAL DEGREE IN COMPUTER ARCHITECTURE
- REGGIANI, ENRICO: Efficient hardware acceleration of deep neural networks via arithmetic complexity reductionAuthor: REGGIANI, ENRICO
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: (DAC)
Mode: Normal
Deposit date: 20/09/2023
Deposit END date: 04/10/2023
Thesis director: CRISTAL KESTELMAN, ADRIAN | OLIVIERI, MAURO
Committee:
PRESIDENT: FELBER, PASCAL
SECRETARI: CANAL CORRETGER, RAMON
VOCAL: YALCIN, GULAY
Thesis abstract: Over the past decade, significant progresses in the field of artificial intelligence have led to remarkable advancements in a widerange of technologies. Deep learning, a subfield of machine learning centered around deep neural networks (DNNs), has playeda pivotal role in driving these achievements. Indeed, DNNs have demonstrated unprecedented accuracy levels in tasks such asimage recognition, speech recognition, and natural language processing (NLP). However, the high computational demandassociated with current DNN models limits their applicability across different platforms and applications.Specifically, the constant increase in the number of parameters and operations required for DNN computations, and the growingcomplexity of their topologies and layers are posing obstacles for a wide range of computing systems, ranging from smallgeneral-purpose CPUs to hardware accelerators targeting HPC and cloud computing environments.In this thesis, we explore various research directions aimed at optimizing DNN computations on modern hardware architectures.We first investigate a novel mathematical technique, called binary segmentation, studiyng its applicability to reduce the arithmeticcomplexity of linear algebra operations involving narrow integers on general-purpose CPU architectures. Additionally, wepropose a novel hardware microarchitecture called Bison-e accelerating linear algebra kernels using binary segmentation. Wedemonstrate that Bison-e achieves up to 5.6×, 13.9×, and 24× improvement than a single RISC-V core in the computation ofconvolution and fully-connected layers of relevant DNNs using 8-bit, 4-bit, and 2-bit data sizes, respectively. Moreover, we showthat Bison-e enhances energy efficiency by 5× for string-matching tasks when compared to a RISC-V-based vector processingunit (VPU). We integrate Bison-e into a complete SoC based on RISC-V showing that it only accounts for a negligible 0.07% areaoverhead compared to the baseline architecture.We then propose Mix-GEMM, a hardware-software co-designed architecture accelerating quantized DNNs, supporting arbitrarydata sizes ranging from 8-bit to 2-bit, including mixed-precision computations. On the software side, we introduce a library thatenhances the existing BLIS framework and exploits custom RISC-V instructions to allow for high-performance matrix-matrixmultiplication on CPU architectures. On the hardware side, Mix-GEMM leverage on the Bison-e microarchitecture to performSIMD computations among narrow integers, with performance scaling as the computational data sizes decrease. Ourexperimental evaluation, conducted on representative quantized CNNs and targeting edge and mobile CPUs, demonstrates thata RISC-V-based edge SoC incorporating Mix-GEMM achieves up to 1.3 TOPS/W in energy efficiency and up to 13.6 GOPS percore in throughput, surpassing the performance of the OpenBLAS framework running on a commercial RISC-V-based edgeprocessor by a factor ranging from 5.3× to 15.1×.Furthermore, synthesis and PnR of the enhanced SoC in 22nm FDX technology shows that Mix-GEMM accounts for only 1% ofthe overall SoC area.We finally explore a novel hardware microarchitecture called Flex-SFU, acceleration complex DNN activation functions. Flex-SFUexpands the set of functional units within deep learning VPUs, used as general-purpose co-processors alongside the main matrixmultiplication units of DNN accelerators targeting HPC and cloud computing. Flex-SFU leverages non-uniform piecewiseinterpolation and supports multiple data formats. Thanks to these features, Flex-SFU achieves an average improvement of 22.3×in mean squared error (MSE) compared to previous piecewise linear (PWL) interpolation approaches. We evaluate Flex-SFUusing over 600 computer vision and NLP models, demonstrating an average end-to-end performance improvement of 35.7%compared to the baseline AI hardware accelerator, while only introducing a 5.9% area and 0.8% power overhead.
DOCTORAL DEGREE IN ELECTRICAL ENGINEERING
- FONTANES MOLINA, POL: Influence of Electrostatic Charge on Lightning Interactions with Aircraft and Wind turbines: An Experimental Approach to a Charge Control System ApplicationAuthor: FONTANES MOLINA, POL
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: (DEE)
Mode: Article-based thesis
Deposit date: 26/09/2023
Deposit END date: 09/10/2023
Thesis director: MONTAÑA PUIG, JUAN | GUERRA GARCÍA, CARMEN
Committee:
PRESIDENT: MARCH NOMEN, VICTOR
SECRETARI: ROMERO DURÁN, DAVID
VOCAL: MÉNDEZ HERNÁNDEZ, YARÚ
Thesis abstract: Lightning strikes to aircraft and wind turbines can lead to substantial repair expenses. These structures often trigger lightning strikes, in the form of bidirectional leaders in the case of aircraft and upward leaders in the case of wind turbines. For airplanes and specific wind turbine blades, isolation from the ground enables the accumulation of an electrostatic charge, which can be further enhanced by their movement.This thesis studies the influence of electrostatic charge on the lightning interactions with aircraft and wind turbines. The study builds from a collaboration between two research groups and industry, synergistically enhancing research capabilities. The outcome is the development of the Hammer system, an active electrostatic charge control system designed specifically for aircraft and wind turbines.The electrification of wind turbine blades and aircraft under fair weather conditions is examined, along with artificial charge compensation techniques to mitigate its effects. This involves developing field methods for studying induced currents in wind turbine blades and conducting experimental studies on ion release from aircraft to control electrostatic charge.The Hammer system, wirelessly controls the net charge of a floating conductor. Through a high-voltage generator connected to a floating corona electrode, the system captures or releases ions to the ambient. The system's successful implementation is demonstrated by achieving bipolar ion emission from an aircraft surface during flight. The duration of the transient state of ion emission is linked to the airspeed and its interplay with ion advection and electrostatic attraction.Regarding wind turbine blades, electrostatic polarization of electrically isolated blades in laboratory conditions reveals a two-step process: rapid polarization of the down conductor followed by gradual charge accumulation at the glass fiber enclosure. The Hammer system effectively neutralizes the potential gradient at the blade root when exposed to intense electric fields.The research also explores the application of vertical conductors with drones to measure atmospheric electricity effects, simulating current induction in wind turbines. A validated model combining partial discharge and vertical motion contributions to current induction is proposed, adaptable for wind turbine use. This model aligns well with field measurements of real wind turbine currents under fair weather conditions.The investigation extends beyond its immediate scope by considering the transferability of results to other fields like geoengineering.In summary, this research delves into the intricate relationship between electrostatic charge, lightning attachment, and protection mechanisms for aircraft and wind turbines. The collaborative effort results in the Hammer system, offering a pioneering solution to mitigate risks and enhance the safety and efficiency of these structures.
DOCTORAL DEGREE IN GEOTECHNICAL ENGINEERING
- PRADES VALLS, ALBERT: Aportaciones de técnicas geomáticas al análisis de los desprendimientos rocososAuthor: PRADES VALLS, ALBERT
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 GEOTECHNICAL ENGINEERING
Department: (DECA)
Mode: Article-based thesis
Deposit date: 15/09/2023
Deposit END date: 29/09/2023
Thesis director: LANTADA ZARZOSA, MARIA DE LAS NIEVES | COROMINAS DULCET, JORDI
Committee:
PRESIDENT: PRAT CATALAN, PERE
SECRETARI: BLANCH GÓRRIZ, XABIER
VOCAL: COPONS LLORENS, RAMON
Thesis abstract: The term rockfall applies to blocks or masses of rock that, after separating from a steep wall, experience free fall and thenimpact against the ground, with the consequent rebound and possible rolling and sliding of rock fragments. Thisphenomenon has great destructive potential due to the high velocities, and thus high kinetic energy, that blocks may reachduring their propagation and may threaten buildings, civil infrastructure and transportation networks. The phenomenonbecomes more complex if fragmentation during rockfall propagation is considered. The present thesis aims to contribute toknowledge of the rockfall process by using geomatic techniques and developing specific models that may contribute to themonitoring of rock cliffs.Monitoring plays an important role in managing risk due to rockfalls in a wide spectrum of applications. Terrestrial or aeriallaser scanning (TLS or ALS) and photogrammetry are geomatic techniques that are frequently used to estimate thedetachment volume over time. These observations allow the expected magnitude frequency of the cliff to be estimated, whichis required to quantitatively evaluate risk. In this thesis, an automated and low-cost continuous time-lapse fixed positioncamera system was developed and implemented to monitor a basaltic cliff. The aim was to test its ability to detect precursoryrockfall movements and quantify volume changes if the rock mass detachment occurs. A methodology was developed tohandle a set of images at different times to detect possible precursory movements. The procedure consists in matching theimages with a reference master image after filtering the vegetation and correcting illumination differences and small cameramovements. The fitted images are used for a forward-backward correlation process that is carried out to detect deformation. Ifdisplacement is detected, a 3D model is built to quantify it. The image process system can detect small precursormovements of around a centimeter.Several real-scale tests were performed in a quarry to analyze the trajectories of falling rock blocks and their fragmentation,which were recorded by three high-speed video cameras. In this thesis, a code was specifically developed to track the 3Dtrajectory of blocks and fragments and to measure velocities before and after the impact. Two different programs wereimplemented, one for the blocks that break and one for those that do not. The captured parameters allow the velocitydistribution of fragments, the restitution coefficients, and the energy balance of the impact to be obtained. The results of thesetests were incorporated into the rockfall propagation model RockGIS.A final issue that is addressed is the characterization of roughness, which is a fundamental parameter of the propagation ofblocks on slopes made up of accumulations of fragments (e.g. talus deposits). One of the limitations of considering a lumpedmass approach when simulating block propagation is that its relative position at impact with the slope is unknown, as thegeometry is not explicitly taken into account. In this thesis, different algorithms are developed to quantify volumes of rockfragments and to define the spatially distributed roughness of the terrain using high resolution 3D point clouds collected withTLS or photogrammetry.
DOCTORAL DEGREE IN MARINE SCIENCES
- FRANCESCANGELI, MARCO: Technologically-sustained ecological monitoring of a coastal fish community with a highly integrated biological and environmental data.Author: FRANCESCANGELI, MARCO
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: (DECA)
Mode: Article-based thesis
Deposit date: 20/09/2023
Deposit END date: 04/10/2023
Thesis director: DEL RIO FERNANDEZ, JOAQUIN | AGUZZI, JACOPO
Committee:
PRESIDENT: COSTA, CORRADO
SECRETARI: MÖSSO ARANDA, OCTAVIO CESAR
VOCAL: CATALÁN ALEMANY, IGNACIO
Thesis abstract: The Monitoring of coastal marine ecosystems has been traditionally carried out with man and vessel-assisted methodologies. In the last decades, new technologies have been progressively integrated by platforms with different levels of teleoperated autonomy. All these platforms are equipped with high-definition video cameras, in order to obtain biological data from the identification of individuals, their classification, resulting in species spatiotemporal counting and sizing. Seafloor cabled video-observatories are being increasingly used to monitor fish behaviour at different temporal scales, but unfortunately, they are without unified data collection and elaboration protocols. Biological data are provided by cameras through the manual counting and classification of organisms. For this reason, new routines for automated organisms¿ classification are required. With temporal studies, comparing biological and environmental data across years, we can observe the effects of different oceanographic and meteorological variables on species¿ phenology. When long time series are obtained, they can be used as proxy for species changes in abundance at diel, seasonal, and even yearly scales, being the amplitudes of counts¿ fluctuations also related to underlying climate regime shifts.This Thesis central objectives is to develop practices for data collection and analysis in relation to the marine ecological monitoring with cabled observatory technologies. For that purpose, the Thesis was carried out using a nearly decadal image data set of biological data (i.e., fish counts for 37 fish taxa) and synchronous multiparametric oceanographic (water temperature, salinity, change of depth as shift in water pressure, and current velocity and direction) and meteorological (air temperature, wind speed and direction, sun irradiance, and rain) data provided by the seafloor cabled video-observatory OBSEA (www.obsea.es). This is located in the north-western Mediterranean, 4 km off Vilanova i la Geltrú (Barcelona, Spain) at 20 m depth. This Thesis first chapter hence focuses on the autecology of an important fishery resource, the common dentex (Dentex dentex), to set the guidelines for the processing and analysis of high-frequency (30 min), large (i.e. decadal), multiparametric time series (i.e., fish counts and oceanographic plus meteorological data), in order to efficiently describe diel and seasonal counts fluctuations (as proxy for local abundance).The Thesis¿ second chapter is centred on the development of pipelines to automatically detect fishes and classify them into species as categories, to speed up the treatment of big amounts of image/video material, as application context for ecological video-monitoring practices. This can be possible only with the development of automated processing routines, trained with ground-truthed tagged datasets. For this reason, the second chapter describes the creation of a training reference dataset of tagged species of two years length temporally collated with the environmental information, as quality indicator of pictures clearness.Finally, the third chapter of the Thesis focuses on the monitoring of the scavenging dynamic of a cetacean carcass, in coastal areas. A specific experimental planning was deployed as in situ experiment, to understand the impact of large punctual organic inputs on coastal marine communities in a framework of increasing global large marine animal species stranding on the coasts.
DOCTORAL DEGREE IN PHOTONICS
- MALAIWONG, NAWAPHAT: Molecular and Cellular Aspects of Proprioceptive Control in C. elegansAuthor: MALAIWONG, NAWAPHAT
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 PHOTONICS
Department: Institute of Photonic Sciences (ICFO)
Mode: Normal
Deposit date: 22/09/2023
Deposit END date: 06/10/2023
Thesis director: KRIEG, MICHAEL
Committee:
PRESIDENT: LOZA ALVAREZ, PABLO
SECRETARI: RAFFA, VITTORIA
VOCAL: CERON MADRIGAL, JULIAN
Thesis abstract: Locomotion behavior is the output of the integrated clues by the nervous system along with proprioceptive regulation, which encompasses responses such as avoiding, feeding, and reproduction. Mechanosensation, the ability to sense mechanical force, relies on mechanically-gated ion channels that convert force into neuronal signals through conformational changes. Unraveling the mechanisms underlying these mechanosensitive channels poses a significant challenge for neurobiologists and cell biologists. My PhD work employed multidisciplinary approaches in biology, physics, mathematics, and engineering to investigate the regulation of proprioception in the model organism C. elegans in the molecular and cellular scales.In my research, I focused on understanding the role of the interneuron DVA during movement and its ability to draft signals from body curvatures. Using genetically modified strains and calcium imaging techniques, I demonstrated that DVA responds to compressive forces through its axon, leading to an influx of calcium ions through the TRP-4 channel. Additionally, I discovered that bending of the worm stretches the DVA axon and activates the potassium ion channel TWK-16. Both channels detect mechanical forces and modulate DVA signal, such interplay encodes calcium signals along the body curves, facilitating the reception and fine-tuning of muscle contractions in different body segments. Moreover, I discovered the critical role of beta-spectrin in maintaining the structural integrity and proprioceptive function in response to force. To delve deeper into the subject, additional research was conducted to examine the role of beta-spectrin in the ageing process and its impact on proprioception and protein expression in C. elegans. Apart from the proprioceptive regulation through neuronal signal, my study revealed that the DVA-specific neuropeptide, NLP-12, is responsible to modulate locomotion behavior. Using transgenic animals, imaging techniques, and protein modification approaches, the results showed that NLP-12 is required to promote the DVA-mediated motor output. Interestingly, first evidences suggest that NLP-12 release is controlled by mechanical force. However, the exact mechanism on such effect will be further characterized.During my PhD research, I developed a novel technique called Fluorescent Landmark Interference (FLInt) for integrating transgenes into the C. elegans genome using CRISPR/Cas9. FLInt is a simple, rapid, and flexible method for establishing transgenic C. elegans strains based on the precise excision of fluorescent genes at a specific locus as markers of integration. FLInt has gained widespread popularity and is now employed as a routine method in C. elegans research laboratories around the world.The novelty of my PhD study lies in its pursuit of both fundamental knowledge and practical applications: (1) to understand the broader concept of mechanosensation and gain valuable insights into how organisms perceive and respond to mechanical stimuli and (2) to offer an accessible and efficient tool for C. elegans research community and enhance future studies using C. elegans model.
DOCTORAL DEGREE IN STRUCTURAL ANALYSIS
- FABRA RUIZ, ARNAU: Modeling of the mixed form of wave problems with correcting terms based on training artificial neural networks: Application to acoustic black holes.Author: FABRA RUIZ, ARNAU
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 STRUCTURAL ANALYSIS
Department: (DECA)
Mode: Normal
Deposit date: 22/09/2023
Deposit END date: 06/10/2023
Thesis director: CODINA ROVIRA, RAMON | BAIGES AZNAR, JOAN
Committee:
PRESIDENT: GAUTIER, FRANÇOIS
SECRETARI: CERVERA RUIZ, LUIS MIGUEL
VOCAL NO PRESENCIAL: GONZALEZ IBAÑEZ, DAVID
Thesis abstract: This thesis presents novel approaches and computational methods for solving wave propagation problems in acoustics and linear elasticity. Stabilized finite element methods in the context of the variational multi-scale method are developed to model the mixed form of the wave equation in time and frequency domains. Additionally, the thesis explores the incorporation of correcting terms based on artificial neural networks to enhance the accuracy and efficiency of the solutions of the numerical simulations.The first part of the thesis focuses on the field of acoustics. The wave equation in its irreducible and mixed form is computed including the contributions from both element interiors and interelement boundaries, which are often overlooked in traditional stabilization methods. Moreover, non-reflecting boundary conditions are employed to reduce spurious reflections. The stability, convergence and performance of the proposed methods are demonstrated through different numerical examples. A really important point of this work is the presentation of a general approach to refine coarse models by introducing a correcting term based on fine solutions. This term is computed and trained making use of learning algorithms, such as the least squares model or a model constructed from an artificial neural network (ANN). This technique is applied to both the time and the frequency domains of the wave equation in the context of acoustics. Its effectiveness is evaluated through multiple numerical examples, where fine solutions with finer discretization in either time or space are used.In the second part of the thesis, the wave equation in the field of elastodynamics is explored. Concretely, stabilized finite element methods are developed for the mixed velocity-stress elasticity equations and their irreducible form, where just the velocity is computed. Both time and frequency domains are considered, with the latter assuming harmonic behavior in time, the study of the mixed form in frequency domain is one of the novelties of this thesis. One of the advantages of using this new mixed form is the flexibility to switch between the primal and dual functional frameworks by appropriately selecting algorithmic parameters, moreover, using the mixed formulation the locking problem is avoided. The proposed formulations are validated through various numerical examples, including a convergence study. Finally, as a case study we consider acoustic black holes (ABHs) on beams and plates. These structural configurations are designed to trap flexural elastic waves by gradually reducing the structural thickness according to a power-law profile at the end of a beam or within a two-dimensional circular indentation in a plate. When a propagating wave encounters an ABH, it undergoes a decrease in wavelength and an increase in amplitude, resulting in a reduction in wave propagation speed as it approaches the termination point in the case of beams or the center point in the case of plates. To ensure the optimal functionality of the ABH, it is imperative that the thickness at the termination or center of the structure be exceedingly small, which demands very fine computational meshes. At this point, the previously presented correcting technique based on training ANN is employed to mitigate computational expenses by allowing the use of coarse meshes maintaining the precision of fine meshes. The effectiveness of this approach is demonstrated through different simulations of ABHs on coarse meshes for values of ABH order and residual thickness outside the training test, as well as for different excitation frequencies.
DOCTORAL DEGREE IN SUSTAINABILITY
- MARCILLO DELGADO, JUAN CARLOS: Marco de referencia para la planificación y desarrollo continuo de la comunicación de riesgos y crisis frente a amenazas en SudaméricaAuthor: MARCILLO DELGADO, JUAN 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 SUSTAINABILITY
Department: University Research Institute for Sustainability Science and Technology (IS.UPC)
Mode: Normal
Deposit date: 15/09/2023
Deposit END date: 29/09/2023
Thesis director: ÁLVAREZ GARCÍA, ALICIA | GARCIA CARRILLO, AGUEDA
Committee:
PRESIDENT: GUERRA DE CASTILLO, ZOILA YADIRA
SECRETARI: PORCAR BECKER, INGEBORG
VOCAL NO PRESENCIAL: RODAS HERNÁNDEZ, OSCAR ROLANDO
Thesis abstract: Research on risk communication and crisis communication (RC&C) is a crucial aspect to foster population resilience in the face of major hazards, especially in developing economies where there are greater social vulnerabilities. The objective of this doctoral thesis is to propose a framework to guide the planning and ongoing development of CR&C strategies in South America. The methodological framework, based on data mining, involves the use of different textual mining techniques, according to the structure of each of the data, which make it possible to visualize the relationships between textual objects; classify the objects of interest; carry out comparative analyses at the country level; and study CR&C trends. The units of analysis focus on different types of textual data such as documents associated with risk and crisis management planning, scientific publications, communiqués issued via tweets, and information from the Regional Logistics Center for Humanitarian Assistance that is located in Panama in the period 2017-2021. It identifies the main CR&C and Risk and Crisis Management (RC&C) strategies that South American RC&C Services should consider in order to make their communications more effective throughout the crisis cycle. Strengths and weaknesses of the analyzed countries' planning on these strategies are identified. The influence of economic, political, social, demographic, technical and disaster risk factors on the development of CR&C and GR&C strategies is identified. The analysis of different GR&C documents allows differentiating five minimum components of CR&C in South America: i) early communication planning; ii) information and communication system planning; iii) quality management of communication and communicators; iv) risk and crisis awareness; and v) stakeholder consolidation. The bibliometric mapping of 330 scientific publications differentiates five clusters for CR&C in South America: i) factors for risk communication in vulnerable areas; ii) factors for health and crisis communication; iii) elements for communication of human and environmental exposure to contaminants; iv) management of the continuity and quality of communication, v) factors that enhance communication. It is identified that most of the factors revealed through the bibliometric analysis are aimed at strengthening communication systems and increasing risk awareness of vulnerable people. The analysis of 40,082 official tweets from the Ministries of Health of eight South American countries during COVID-19 identified 18 communication topics associated with: i) communication of the impact and monitoring of the threat; ii) communication of measures to reduce the risk of the threat; iii) visibility of the multidimensional nature of the problem; iv) communication of the capacity of the health system to deal with threats; and v) communication of mechanisms to strengthen vulnerable groups in the face of threats. The above results allow proposing a framework of strategies for disaster risk and humanitarian crisis communication in South America. This doctoral thesis contributes to: i) understand the factors affecting the development of CR&C; ii) recognize the efforts envisaged by regional policy; iii) analyze the advantages and disadvantages of CR&C planning at the country level; iv) verify the conformity of planning with contemporary international frameworks such as the Sendai Framework for Risk and Disaster Reduction 2015-2030; v) generate knowledge for decision making; and vi) serve as input to accelerate the implementation of strategies in the context of risk and crisis management (R&CM).
- NARANJO SILVA, HÉCTOR SEBASTIÁN: Análisis de la producción hidroeléctrica en base a las implicaciones en la sostenibilidad energéticaAuthor: NARANJO SILVA, HÉCTOR SEBASTIÁN
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: Normal
Deposit date: 13/09/2023
Deposit END date: 27/09/2023
Thesis director: ALVAREZ DEL CASTILLO, JAVIER
Committee:
PRESIDENT: TOLLIN, NICOLA
SECRETARI: MORATO FARRERAS, JORDI
VOCAL NO PRESENCIAL: RÍOS OSORIO, LEONARDO ALBERTO
Thesis abstract: Technical, ecological, territorial, and cultural transformations at various levels and spaces of society where hydroelectric projects exist often involve conflicts, new knowledge regimes, different local practices, global mitigation frameworks, and water resource management. Therefore, the fact that hydroelectricity does not rely on fossil fuels should not imply the absence of adverse environmental effects. In fact, its development and construction require dams, concrete infrastructure, road openings, water channels, transmission power towers, and other facilities that are not new, but they do possess specific characteristics, benefits, and disadvantages.Globally, hydroenergy production presents a macro view of advantages, but little is discussed about the disadvantages and issues that arise from the construction of these structures and their surrounding systems. This research aimed to analyze hydroelectric production based on implications for energy sustainability. Through an analytical-experimental methodology with a quantitative approach, several axes were investigated.In the analysis, the thesis first involved visits to various hydroelectric projects in Ecuador, mainly, and adjacent communities to verify the environment, infrastructure, operation, collect water samples, and gather information through surveys of people living in these areas. These activities provided research elements and data on the changes contrasted since the construction of hydropower plants.Additionally, the research conducted 183 surveys to gather information and perspectives from communities near Ecuador's largest project, collected 10 water samples for physicochemical water analysis in five hydropower projects, established a relationship between hydroelectric production and technical, social, and environmental variables, and developed a connection between hydroelectricity and sustainability.The research concludes that hydroelectric energy presents itself as a renewable technology that provides benefits such as water supply to communities, flood control, greenhouse gas reduction, and clean energy as a low-carbon option. However, emerging problems exist due to unregulated exploitation and large-scale infrastructure with dams that alter the environment, making this source not entirely sustainable.Furthermore, there are parameters that impact hydroelectricity; socially, changes in customs and movements of people from their places of origin were observed; environmentally, parameters include changes in water quality, wildlife death, reduction in river fish populations, erosion, and seasonal changes; technically, parameters such as water usage for generation, construction type, and water variations that reduce plant efficiency were verified.It is conclusive that there are hidden impacts for every megawatt produced through hydroelectricity, and its generation structure is not highly clean due to the significant water resource requirement per kWh. However, hydroelectricity significantly contributes to climate change mitigation compared to fossil fuel energy production, but the availability of water resources varies, altering ecosystems and requiring careful attention due to the hidden, often intangible costs such as environmental, social, and technical parameters that occur.
DOCTORAL DEGREE IN TEXTILE AND PAPER ENGINEERING
- AMINI, ELAHE: IONIC LIQUID-ASSISTED THE PREPARATION OF TRANSPARENT CELLULOSIC BIOCOMPOSITE FILMSAuthor: AMINI, ELAHE
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 TEXTILE AND PAPER ENGINEERING
Department: (DEGD)
Mode: Normal
Deposit date: 25/09/2023
Deposit END date: 06/10/2023
Thesis director: RONCERO VIVERO, MARIA BLANCA | VALLS VIDAL, CRISTINA
Committee:
PRESIDENT: COCA SANZ, MÓNICA
SECRETARI: VIDAL LLUCIA, TERESA
VOCAL NO PRESENCIAL: CADENA CHAMORRO, EDITH MARLENY
Thesis abstract: Interest in new environmentally friendly cellulose-based products has tremendously increased in recent years.Cellulose-based composites come in various forms and have potential applications in construction, automotive,packaging, sports, biomedical, and defense sectors due to their abundance and versatility as a biopolymer. As aresult, all-cellulose composites (ACCs) have gained significant research interest. ACCs are a class ofbiocomposites where the matrix is a dissolved and regenerated cellulose, while the reinforcement isundissolved or partly dissolved cellulose. This dissertation discusses a novel approach to developing highbarriercellulose nanocomposite films with the assistance of an ionic liquid as a smart nanowelding agent toassemble nanometric cellulose structures. The aim of this study was focused on modifying regeneratedcellulose by employing in situ ring-opening polymerization of e-caprolactone (CL) and L-lactide (LA)monomers, due to the higher amount of available initiating hydroxyl groups. ¿Grafting¿ copolymerizationstrategy can render the advantages of biofiber and impart polymer properties onto it, and the performance ofbiocomposites can be increased. Both polylactide and polycaprolactone as well as zinc oxide nanoparticleswere used as reinforcements. The first part of the thesis is a review article that deals with the potential ofprominent ionic liquids, with a focus on the selective and effective dissolution of cellulose, lignin, andhemicellulose from lignocellulosic biomass. It examines the factors influencing the solubility of biomassmatrices and describes the ionic liquid-assisted production of biomass-based products of four different types:all cellulose-based composites and nanocomposites, all-wood composites, aerogels, and hydrogels. This reviewarticle provides useful information about the use of ionic liquids to develop products with a lesser impact onhealth and the environment, which can help researchers at large-scale pretreatment plants devise greener, moreefficient processes. It also identifies research gaps with a view to improving future prospects and meetingchallenges in ionic liquid technology. The second and third parts of the thesis were based on a green, efficientapproach to rendering hydrophobic PCL (Poly e-caprolactone) and PLA (Polylactide) compatible withhydrophilic cellulose fibers by using the ionic liquid 1-ethyl-3-methylimidazolium acetate ([Emim]OAc) in thepresence of ZnONPs. The [Emim]OAc and ZnONPs were efficiently used to catalyze L-lactide and e-caprolactone ROP from the skeleton of cellulose as a backbone under mild conditions. The role of eachcomponent of the film was investigated with a view to optimizing water and oxygen barrier properties,strength, and UV-blocking capacity. Additionally, the study aimed to improve antioxidant activity and opticalproperties. The last part of this thesis involved designing a novel all-cellulose nanocomposite (ACNC) film.Ionic liquid also assisted in the green synthesis of lignin nanoparticles (LNPs) through a sonication method,allowing for even distribution without the need for additional reducing agents or stabilizers. ACNC films wereproduced using a partial cellulose dissolution process that trapped the synthesized LNPs. The studyinvestigated the effect of LNP amount on the mechanical strength, antioxidant and antimicrobial activities, aswell as UV, water vapor, and oxygen barrier properties of the prepared nanocomposite films. The findingsdemonstrate a simple and ecologically responsible method for producing bio-based nanocomposite filmsreinforced with lignin nanoparticles as entirely bioderived fillers for advanced applications.
Last update: 27/09/2023 04:30:23.