Doctoral School

Reading date: 08/11/2024

• DEVIGILI, MARIANO: Applications of the OCATA optical layer digital twin
  
  Author: DEVIGILI, MARIANO
  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: 01/10/2024
  Reading date: 08/11/2024
  Reading time: 10:00
  Reading place: Defensa publica Sala Juntes - Edifici B6 - 1a planta (FIB) - Campus Nord - Barcelona
  Thesis director: VELASCO ESTEBAN, LUIS DOMINGO | NAPOLI, ANTONIO
  Committee:
       PRESIDENT: CASELLAS REGI, RAMON
       SECRETARI: COMELLAS COLOME, JAUME
       VOCAL: SAMBO, NICOLA
  Thesis abstract: Optical transport networks (OTNs) are a core infrastructure and key-enabler of today’s hyper-connected society as most of the Internet data traffic is transferred over optical fibers. Traffic demand is experiencing rest-less growth as Internet-services are reaching increasing audience and capacity-hungry applications are arising (e.g., industry 4.0). In view of this, constant innovation is required in OTNs to accommodate the requested capacity while minimizing the cost. In this scenario, digital twins (DTs) – intended as a combination of models self-adjusting with their physical counterpart and of algorithms acting on the network for specific applications – are being proposed as a solution for: 1) maximizing the transport capacity by reducing the network margins; 2) pave the way towards optical network automation. The main objective of this PhD Thesis is to improve network operation based on the use of DTs algorithms and models for failure management, lightpath provisioning and optical amplifier control. To achieve this goal, different machine learning (ML) algorithms were investigated and the capabilities of the OCATA DT were extended. This main goal is achieved by the following three specific goals:1. Applications of Optical Layer DT During Network Operation. The OCATA capabilities are extended for quality of transmission (QoT) estimation and failure management. Tailor-made features are extracted from IQ constellation samples, which show correlations with QoT metrics and with failures-induced signal degradations. Next, specific ML-based models and algorithms for QoT estimation, soft-failure detection, identification and severity estimation are proposed. Results from both simulation and experiments show noticeable accuracy on the estimation of QoT and on the prediction of failures affecting the transmitter, optical filters and amplifiers. Furthermore, this approach was confirmed also for detecting and identifying spectrum anomalies. 2. Applications of Optical Layer DT for Lightpath Provisioning. OCATA capabilities are extended for modulation formats besides 16-quadrature amplitude modulation (QAM) and for digital subcarrier multiplexing signals (DSCM). Firstly, an algorithm for lightpath provisioning is proposed and evaluated based on simulations. Secondly, I experimentally evaluate its accuracy to predict the impact of optical filtering penalties. The simulations show an overall high accuracy for different signal formats and demonstrate their viability for lightpath provisioning. Moreover, the models showed the most advantageous trade-off between accuracy and execution time when compared with other existing methods. Finally, the experimental results demonstrate the feasibility of implementing such models to perform quality of transmission estimation for DSCM signals.3. Application of Optical Layer DT for Amplifier Control. DT models were designed to assist a network controller in performing informed decisions when re-configuring dynamically optical amplifiers under varying channel loadings. Experimental characterization processes were performed on pluggable EDFAs. Then, ML models based on deep learning (DL) and ensemble methods were compared in terms of accuracy and computation speed. After time-consuming hyper parameter optimization (HPO) procedures, DL models showed to achieve both the best performance on the training data set and the best generalizability on unknown dataset. Furthermore, it was shown that substantial generalization error reduction can be achieved employing transfer learning (TL) techniques.
  

• FLORES VÁZQUEZ, CARLOS ALBERTO: CeCi: Design, Development and Validation of an Affordable Consumer Service Robot as a Social Robot
  
  Author: FLORES VÁZQUEZ, CARLOS 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 AUTOMATIC CONTROL, ROBOTICS AND VISION
  Department: Department of Automatic Control (ESAII)
  Mode: Normal
  Deposit date: 02/07/2024
  Reading date: 08/11/2024
  Reading time: 11:00
  Reading place: Sala de Juntes de la Facultat de Matemàtiques i Estadística (FME), Campus Diagonal Sud, Edifici U. C. Pau Gargallo, 14 08028 Barcelona
  Thesis director: ANGULO BAHON, CECILIO
  Committee:
       PRESIDENT: VALLÈS PERIS, NÚRIA
       SECRETARI: REPISO POLO, ELY
       VOCAL: TREJO RAMÍREZ, KARLA ANDREA
  Thesis abstract: This research discusses elements to be considered for designing, developing, and validating a service robot that performs its task in different social environments. Due to the social focus of the provided services, technical considerations are demanded toaccomplish the task, and the acceptability of use for the people interacting with the robot.The first stage of the research considers previous cases on the implementation of service mobile robots, their analysis, and the motivation of how to solve their acceptability and use by people. The developmental part presents the technical and social considerations for implementing the CeCi (Computer Electronic Communication Interface) social robot. Two main problems of social robots and service robots in social environments currently on the market are addressed, which are the main focus of this research: First, their costs are not affordable for many companies, universities, or individuals in developing countries. The second is that their design is exclusively oriented to the functional part with a viewpoint inherent to the engineers who create them without considering the end users’ views, preferences, or requirements, especially for their social interaction. This last reason ends up causing a certain aversion to the use of this type of robot.In response to the issues raised, an affordable, low-cost prototype is proposed, starting from a commercial platform for research development and using open-source code. The robot design presented here is centered on the criteria and preferences of the end user, prioritizing acceptability for social interaction. This document details the selection process and hardware capabilities of the robot. Moreover, a programming section is provided to introduce the different software packages used and adapted for social interaction, the main functions implemented, as well as the new and original part of the proposal. A list of applications currently developed with the robot and possible applications for future research are discussed.As a final step, the complete implementation of the social robot is explained based on two design elements. The first element is the use of the design thinking methodology for the development and implementation of the robot. The second element, of a technical nature, is a previous taxonomy generated for defining socially-aware robot assistants. Therefore, in the construction process, special emphasis is placed on the realization of prototypes and their adjustment to the users’ preferences. Interviewswith users who were unaware of the robot’s capabilities were used to improve and validate the prototype. These prototypes and their evolution will be presented based on the adjustments performed. Beyond the users’ feedback, previous experiences exposed to the state of the art were considered for the evolution of this robot. The entire methodological process is validated with surveys, and results are presented as a SWOT (strengths, weaknesses, opportunities, and threats) analysis for future improvements.
  

• NAZARETH LOPEZ, RAFAEL: Continuous-discrete numerical modeling of the thermomechanical behavior of granular media supported by experimental campaign
  
  Author: NAZARETH LOPEZ, RAFAEL
  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: Normal
  Deposit date: 01/10/2024
  Reading date: 08/11/2024
  Reading time: 12:00
  Reading place: Defensa pública Sala Zienkievicz. (CIMNE C/Gran Capità s/n, Edifici C1, Campus Nord, Barcelona).
  Thesis director: FRANCI, ALESSANDRO | OÑATE IBAÑEZ DE NAVARRA, EUGENIO
  Committee:
       PRESIDENT: CREMONESI, MASSIMILIANO
       SECRETARI: BONET CARBONELL, JAVIER
       VOCAL: WU, WEI
  Thesis abstract: Granular materials, ranging from soils and food grains to construction aggregates and pharmaceutical powders, are prevalent in both natural and industrial contexts. Their complex physical behavior, which can exhibit both solid- and fluid-like properties depending on several external and internal factors, arises from their discrete composition, characterized by intricate particle interactions. This complexity is further amplified by thermal effects, which explains the current gaps in achieving a comprehensive understanding of the thermomechanics of granular matter. This thesis explores the thermomechanical behavior of granular media from different perspectives, including numerical and experimental analyses. In particular, two key thermal effects are addressed throughout the research, namely, heat generation from mechanical energy dissipation and thermal expansion in confined systems. In the physical experiments, the heat generation phenomenon is studied for granular mixing operations using two widely-used industrial devices: a rotating drum and a bladed mixer. In both setups, the temperature rise of granular flows is measured under varying operational conditions. Regarding numerical investigations, two approaches are developed. An efficient Discrete Element Method (DEM) framework is used to investigate heat generation mechanisms and provide insights into the thermomechanical behavior of granular flows. Additionally, a novel multiscale numerical framework is developed, coupling continuous and discrete methods through a machine-learning-based surrogate model, to efficiently simulate thermal expansion in confined granular media. In both strategies, the underlying objective is to reduce the high computational cost of simulating granular media, allowing for large-scale analyses in terms of both time and space.
  

• RIMBAUD BLENGINI, TATIANA: Poetas de la arquitectura en Uruguay. Construcciones para la nueva nación, 1894-1914
  
  Author: RIMBAUD BLENGINI, TATIANA
  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 THEORY AND HISTORY OF ARCHITECTURE
  Department: Department of History and Theory of Architecture and Communication Techniques (THATC)
  Mode: Normal
  Deposit date: 29/07/2024
  Reading date: 08/11/2024
  Reading time: 10:00
  Reading place: Presencial (ETSAB. Sala de Graus)
  Thesis director: ROSSELLO NICOLAU, MARÍA ISABEL
  Committee:
       PRESIDENT: SALA GARCIA, TERESA MONTSERRAT
       SECRETARI: NAVAS FERRER, MARIA TERESA
       VOCAL: ALEMÁN KSIAZENICKI, LAURA
  Thesis abstract: The present work addresses the brief and complex moment of the turn from the 19th to the 20th century from the perspective of the history of architecture. The objective is to explore the architecture of the end of the century in Uruguay and its relationship with the country's modernization and consolidation processes. To do this, it proposes from a necessarily disciplinary perspective the scope of the proposals that collectively shaped the Uruguayan nation and capital during a short period of explosive growth.The proposed time cut takes as its beginning the year 1894, when the first architect graduated from the Faculty of Mathematics -the first architectural training institution in the country- and 1914, the last year of existence of that institution that later gave rise to the Faculty of Architecture (1915). Furthermore, 1914 was the year of the creation of the Society of Architects of Uruguay and the beginning of the First World War, among other important events that marked a general change in the situation.The architects working during that period emerged from a predominantly polytechnic professional training in the country, which became a field of opportunity for design and formal exploration. The qualities recognized in their works appeal to the professional responsibility of the collective construction of the necessary structures for the functioning of the State. Therefore, the starting point hypothesis of this is that at the beginning of the 20th century, the architects of the first generations of technicians trained in Uruguay assumed the responsibility of creating the architectures of the new nation.The work is structured into five chapters that address different aspects within the broad scope of the study. On the one hand, the people involved with the urban and architectural projects to assemble the nation are identified. The areas of professional training are investigated in terms of their composition and transformation throughout the period. The labor, professional, and corporate organizations are observed, as well as the debates and public demonstrations the architects carried out collectively.On the other hand, the works and projects of architecture are taken as manifestations of the modernization strategies deployed, both from the national scope of the entire territory and in the exponents of the city's urban life, particularly in the capital of the Republic. Thus, the structures associated with consolidating the state institution, those related to the healthcare project, and those of public education at all levels are included. In the same sense, the capital city is analyzed as an urban project of the nation. The actions of the technical body linked to the municipality are reviewed. The city project is addressed in two large areas: public life, through leisure structures, and private life, in housing.Finally, the idea of the constructions for the new nation is taken up and the country's first professionals' role in them is analyzed. A reflection is presented on the possible reasons for the analyzed phenomena ephemerality and repercussions. It has, to this day, incorporated a look at the historiographic and heritage assessment of the legacy of these architectures.This text aims to collaborate in generating architectural history knowledge that makes it possible to make visible and value the architectural and urban dimension carried out in Uruguay between 1894 and 1914, both in the disciplinary and cultural context, at the national level, and in possible international links. It is expected that this sharing will invite discussions and new inquiries into the various architectures carried out in Uruguay throughout its history.
  

Reading date: 11/11/2024

• NAVARRO BARBOZA, HECTOR: Experimentally constrained organic aerosol chemical and absorption properties in the atmospheric chemistry MONARCH model
  
  Author: NAVARRO BARBOZA, HECTOR
  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: Normal
  Deposit date: 25/09/2024
  Reading date: 11/11/2024
  Reading time: 10:00
  Reading place: Place: ETSECCPB UPC, Campus Nord Building C1. Classroom: 002 C/Jordi Girona, 1-3 08034 Barcelona
  Thesis director: JORBA CASELLAS, ORIOL | PANDOLFI, MARCO
  Committee:
       PRESIDENT: SICARD, MICHAEL
       SECRETARI: BADIA I MORAGAS, ALBA
       VOCAL: PIÑEIRO IGLESIAS, MARIA
  Thesis abstract: Organic aerosols (OA) are a significant component of particulate matter (PM) in the atmosphere, accounting for 20-90% of total PM in Europe. OA plays a fundamental role in air quality, human health, and climate change. This Ph.D. thesis aimed to advance the understanding of OA characterization and optical properties, particularly focused on light-absorbing OA, termed brown carbon (BrC). This research used detailed observations from experimental campaigns and modeling techniques. Observational data were provided by the EGAR-IDAEA group, and the modeling part was developed at the BSC-AC group. The Multiscale Online Nonhydrostatic AtmospheRe CHemistry (MONARCH) model was further developed and used for all studies in this thesis.In the first study, we analyzed the chemical composition of coarse and fine PM simulated by the MONARCH model across three different environments in northeastern Spain (Barcelona urban, Montseny regional and Montsec remote sites). The urban site was characterized by mixed biogenic and anthropogenic sources, the regional site was primarily dominated by biogenic, and the remote site showed low concentrations except during long-range transport dust episodes. Sea salt aerosols played a fundamental role in the urban environment, while mineral dust had the largest impact during spring. In the second study, analysis of carbonaceous aerosols (black carbon, BC, and OA) using three emission inventories in the MONARCH model highlighted the importance of model resolution and detailed emission estimates. Traffic was the main contributor to BC on the urban site, with significant contributions from residential wood combustion (RWC) and shipping. Discrepancies were found in spatiotemporal disaggregation and the treatment of condensables in RWC emissions, highlighting uncertainties in OA due to emission characterization and limited secondary aerosol production in the model.The third study examined the variability of OA refractive imaginary index (k) from five sources using data from 12 European monitoring stations. The model performed well in simulating OA mass concentrations, identifying residential emissions as a major source during the colder months and secondary OA (SOA) during warmer periods, with a significant contribution of shipping emissions near ports. Optimizing k values at 370 nm revealed significant variability influenced by emission sources and environmental conditions.In the fourth study, we implemented a BrC parameterization in MONARCH, including a photobleaching effect. The BrC absorption of an annual simulation was evaluated with the European observations used in the third study. Results showed underestimations of the model BrC absorption, likely due to uncertainty in the BrC emission estimates. Through sensitivity runs perturbing BrC sources the model bias improved significantly. BrC contributes to light absorption, especially during winter as a result of increased biomass burning and biofuel emissions, highlighting important implications for climate modeling.The work carried out in this Ph.D. advances the understanding of OA and BrC and highlights the need for better representation of OA emission, formation processes, and optical properties in atmospheric models. These results will aid modelers in quantifying radiative effects of OA and their climate implications.