Doctoral School

Reading date: 23/01/2025

• MAUREIRA ALEGRÍA, GRACE KELLY: A Multi-Objective Integer Programming Approach for Synergistic Tenant Mix Optimization in Shopping Centers
  
  Author: MAUREIRA ALEGRÍA, GRACE KELLY
  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: 16/12/2024
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: HEREDIA CERVERA, FRANCISCO JAVIER
  Committee:
       PRESIDENT: HASHEMKHANI ZOLFANI, SARFARAZ
       SECRETARI: SOLÀ VILALTA, ALBERT
       VOCAL: GARCIA GONZALEZ, JAVIER
  Thesis abstract: A shopping center's profitability is significantly influenced by its Tenant Mix, which refers to the strategic combination and placement of different retail categories within the center. However, selecting the optimal Tenant Mix has traditionally been based on experience and intuition rather than data-driven approaches. This study addresses this gap by developing a systematic, data-driven optimization model aimed at maximizing profitability through optimal tenant placement.The methodology used in this research involves the development of a Multi-Objective Integer Programming model. This optimization model aims to maximize the combination of three components in its objective function: rental income, sales revenues, and tenant synergy. Constraints are related to the leasable area available for each retail category and the synergistic configuration influencing tenant placement. The data analyzed comes from 27 shopping centers managed by CBRE Spain, covering the period from 2015 to 2022, with the exclusion of 2020 due to the temporary closure of shopping centers during the COVID-19 pandemic.In order to incorporate rental income into the optimization model's objective function, a semi-log regression model was developed. The model considers the monthly rent per square meter as the dependent variable and factors such as store size, store location, tenant category, tenant’s sales per square meter, anchor status, distance to the nearest anchor, and shopping center type as independent variables. The empirical analysis identified that store size, location, anchor status, and retail category significantly affect rental rates. Notably, stores on lower floors tend to command higher rental rates compared to those on upper floors, while the distance to the nearest anchor tenant does not significantly affect rental values.One of the key contributions of this research is the incorporation of tenant synergy into the optimization model, which captures the beneficial interactions between neighboring tenant categories. By analyzing historical data from the 27 shopping centers, specific configurations of neighboring retail categories were identified as having the potential to enhance sales revenues. These configurations were scored based on their impact on sales, and the model aims to maximize these synergy scores, along with rental income and sales revenues, to achieve the most profitable Tenant Mix.The optimization model was applied to six shopping centers: one from each cluster, with one analyzed in greater depth. Three scenarios were evaluated: "Last Layout," "Only Vacancies," and "From Scratch." In all scenarios, the model used 50 combinations of weighted objectives, producing a three-dimensional Pareto frontier. In the "Last Layout" scenario, the model was applied only to the occupied units in the latest tenant configuration (as of December 2022). For smaller centers, rent and sales were lower, but synergy improved, while larger centers saw overall gains in rent, sales, and synergy.In the "Only Vacancies" scenario, the model optimized unoccupied units, keeping the current Tenant Mix unchanged. Results confirmed that the synergistic configurations derived from historical layouts provided optimal solutions, demonstrating the model's flexibility. The "From Scratch" scenario involved a complete reconfiguration, with rent and sales remaining stable across the 50 combinations but greater variability in synergy. This scenario offers strategic insights for landlords aiming to reimagine Tenant Mix for improved financial performance and synergy.The encouraging results highlight the model’s practical utility and strategic potential for retail space management, making it a reliable tool for optimizing the Tenant Mix in shopping centers. Landlords can leverage the insights from this model to make informed decisions about tenant selection and placement that align with their long-term objectives.
  

Reading date: 24/01/2025

• FIOL DURAN, VICTÒRIA INMACULADA: A Mallorca, S'Arenal. Dibuixos d'un paisatge encobert. Traçats per a un nou model territorial.
  
  Author: FIOL DURAN, VICTÒRIA INMACULADA
  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: 17/12/2024
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: EIZAGUIRRE GARAITAGOITIA, FRANCISCO JAVIER | CORTELLARO, STEFANO
  Committee:
       PRESIDENT: PARCERISA BUNDO, JOSEP
       SECRETARI: GALINDO GONZALEZ, JULIAN
       VOCAL: SIMÓN ROJO, MARIAN
       VOCAL: ANASTASIA, CATERINA
       VOCAL: HORRACH ESTARELLAS, GABRIEL PERE
  Thesis abstract: Platja de Palma, Mallorca, is a strategic place for its combination of natural attractions and its geographical location, as well as being a clear setting for the construction and transformation of the pre-existing landscape. This is not only due to its having been one of the laboratories in which to experiment with tourist landscapes, but also as it has had a leading role in some of the main actions to improve seasoned tourist destinations over recent years.All these actions aim to rebuild a territory that was once idyllic for summer holidaymakers and which conserves hidden qualities, with risks and threats for the future, but hidden qualities that are able to be restructured.This doctoral thesis aims to analyse, describe, identify, develop and classify the territory of Platja de Palma based on its free open spaces ¤C squares, parks, woodland, residential areas, sand and beaches ¤C in their original state and it considers the evolution of the elements which remain, which are transformed, which disappear, which are grouped together or which become dispersed, for example. In other words, it aims to understand the structure of the countryside and strike a balance between that which has been constructed and that which has not. It will take the concept of ¡°constructed¡– in the most literal sense of the word, but at no point will it consider non-urban or urbanised space as exempt from form, construction or use. In fact, the whole territory is a space constructed to different extents and this research shows that less density and solidity in constructed areas implies greater value.This updated project aims to explore new ways to continue sharing tourism, which is here to stay, as well as the landscape supporting it.This research project also intends to use the methodology of zoning, classification and the nomenclature of public spaces and their systems, as trialled and applied in conventional urban planning. It is therefore clear that the coastal territory is unique and that it is necessary to offer specific features for the new systems of unoccupied spaces and their dynamics within the territory of S’Arenal, which are always linked to supporting its landscape.The features retained aim to better understand the particular features of open spaces in the coastal territory of Platja de Palma. These features are key to creating structures which readjust the existing territorial model together with a study of their relationships and interactions of the support analysed. Today there are new challenges to be faced with the intrinsic objective of using mapping.Maps and plans are descriptions referring to territories¡fl and cities¡fl pasts and presents. They are also interpretations that speak of the conception of the space and the relationships that residents establish with it. They go beyond being a mere representation of what is known, making way for unknown elements, values and relationships to appear. They anticipate and induce changes to the landscape and project the future. They will therefore condition the future regeneration developments and modifications to Platja de Palma.In short, the relevance of the biogeophysical support determining development is recognised. The network will address flow management and improve the permeability of the current limits, as well as transitions between urban and rural uses. It will also sketch out a well-balanced blend of forests, agriculture and cities integrated into a sequence of landscapes all the way to the sea. It is only by restoring the metabolic cycles of the land and water, and increasing biodiversity and reinforcing its environmental function, that Platja de Palma can be transformed into S¡flArenal: a privileged area combining urban, rural and agricultural values to restore a typical landscape.
  

• FULLANA PONS, AÏDA MAGDALENA: Management strategies of Meloidogyne-resistant plant germplasm to avoid virulence selection
  
  Author: FULLANA PONS, AÏDA MAGDALENA
  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 AGRI-FOOD TECHNOLOGY AND BIOTECHNOLOGY
  Department: Department of Agri-Food Engineering and Biotechnology (DEAB)
  Mode: Normal
  Deposit date: 16/12/2024
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: SORRIBAS ROYO, FRANCISCO JAVIER | GINÉ BLASCO, ARIADNA
  Committee:
       PRESIDENT: CASTILLO CASTILLO, PABLO
       SECRETARI: SERRANO PORTA, LIDIA
       VOCAL: PISA MATA DA CONCEIÇÃO, ISABEL LUCI
       VOCAL: HELDER, JOHANNES
       VOCAL: MORTON JUANEDA, ANA
  Thesis abstract: During the development of the PhD, several studies were conducted to explore the potential of plant resistance for the management of Meloidogyne in horticultural crops, none of which promoted the selection of virulent populations in the resistant germplasms used. Specifically: i) the effect of three growing seasons of resistant germplasm rotation; ii) the effect of Solanum torvum as a tomato rootstock as a method of alternating resistance sources in monoculture situations; iii) the capacity of zoophytophagous mirids to induce resistance in tomato germplasm susceptible to nematodes to reduce the frequency of use of resistant germplasm.; and iv) the response of potential rootstocks of melon and cucumber or watermelon to quarantine species in Spain as a possible management tool if they are found and not eradicated. The results obtained showed that: i) the rotation sequence with resistant germplasm ( tomato grafted (grft.) onto ‘Brigeor’ - melon grft. onto Cucumis metuliferus - pepper grft. Onto ‘Oscos’ – watermelon grft. onto Citrullus amarus - resistant tomato cv. Caramba) cultivated in plots infested by an avirulent (Avi) or partially virulent (Vi) population of M. incognita to the Mi1.2 resistance tomato gene reduced the Avi population density by 94% and the Vi population density to below detectable levels. Cumulative yield was 1.5 and 2.4 times higher in plots infested with Avi and Vi, respectively, compared to rotation with susceptible germplasm. The Avi population did not acquire virulence to any of the resistant germplasms used in the rotation; ii) the severity of the disease and nematode reproduction in tomatoes grafted onto S. torvum were reduced by 8.6 and 56 times, respectively, compared to non-grafted tomatoes, and yield was up to 87% higher at densities above 1 J2/cm3 of soil. The resistance of S. torvum remained unchanged after three consecutive crops; iii) exposure of susceptible tomatoes to 15 nymphs/plant of Nesiodiocoris tenuis or Macrolophus pygmaeus for 24 hours before transplanting such as (Z)-3-hexenil propanoato volatile emitted by fed tomato plants, reduce nematode’s reproduction until 60, 70 and 45% respectively; and iv) Cucumis metuliferus was immune to M. chitwoodi, highly resistant to M. enterolobii, and resistant to M. luci. Citrullus amarus ranged from resistant to moderately resistant to M. chitwoodi and M. enterolobii, and resistant to M. luci.The results of these studies provide valuable information for nematode control, even in scenarios where species and/or populations virulent to specific resistance genes coexist, which are increasingly common in production areas.
  

• JIMENEZ GUERRA, MAYKEL: Innovative bulk and interfaces management on Q-1D Sb2Se3 based solar cells
  
  Author: JIMENEZ GUERRA, MAYKEL
  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: 31/10/2024
  Reading date: 24/01/2025
  Reading time: 10:00
  Reading place: Defensa pública a l'Aula A1.08, EEBE, campus Besós
  Thesis director: SAUCEDO SILVA, EDGARDO ADEMAR | SÁNCHEZ GONZÁLEZ, YUDANIA
  Committee:
       PRESIDENT: SPALATU, NICOLAE
       SECRETARI: PLACIDI, MARCEL JOSE
       VOCAL: GARCÍA SÁNCHEZ SÁNCHEZ, MARIO FIDEL
  Thesis abstract: This thesis investigated antimony Q-1D (Sb)-based solar cells as a promising alternative for sustainable energy generation, addressing critical challenges related to material properties, interfaces, and device architecture. Innovative strategies were developed to optimize optoelectronic properties and improve conversion efficiency, focusing on Sb2Se3, but including also preliminary studies on the Sb2(S,Se)3 solid solution, as well as exploring cadmium-free (Cd-free) materials as electron selective transport layers (ETL).A major achievement was the optimization of the Sb2Se3/CdS interface using chemical etching techniques, such as KCN treatment, which increased the average efficiency of solar cells from 4% to 5%, reaching 5.3% in the best-performing sub-cell. These treatments not only enhanced surface passivation but also altered surface polarity, resulting in the formation of a "buried junction" that improved the fill factor and overall energy conversion efficiency.High-pressure thermal annealings proved effective in enhancing crystal quality by increasing grain size, promoting preferred crystal orientations, and reducing defect density, which enabled a 5.8% efficiency using a new co-evaporation method. These findings demonstrate the feasibility of these techniques to improve device performance and reproducibility.Cadmium-free or significantly Cd-reduced configurations were explored to reduce environmental impact, achieving an efficiency of 6.6% in superstrate-configuration devices based on Sb2(S,Se)3, approaching the 7.6% benchmark achieved with CdS. In the substrate configuration, a Cd-free Sb2Se3 cell reached an efficiency of 5.2%, surpassing the 4.8% achieved with CdS, highlighting the potential of alternative materials to replace cadmium.Despite the progress made, several challenges remain, such as ensuring the stability of Sb2Se3 interfaces under operational conditions and optimizing new materials like SbSeI and SbSeBr. Improving the scalability of fabrication processes and the cost-effectiveness of new treatments are also key areas for future research. The results of this thesis provide a solid foundation for developing more efficient and sustainable Sb2Se3-based solar cells, emphasizing the importance of continued innovation in materials science and device engineering to overcome the remaining challenges and advance toward more scalable and efficient photovoltaic technologies.
  

• LOPES E SILVA, BRUNO MIGUEL: Artificial Intelligence to Improve Plastic Molding Processes
  
  Author: LOPES E SILVA, BRUNO MIGUEL
  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: 17/12/2024
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: ALENYÀ RIBAS, GUILLEM | CHARRUA DE SOUSA, JOÃO MIGUEL
  Committee:
       PRESIDENT: BRANCO SIMÕES DA SILVA, CATARINA HELENA
       SECRETARI: ÁLVAREZ NAPAGAO, SERGIO
       VOCAL: SORGATO, MARCO
  Thesis abstract: This thesis advances the field of production processes, specifically injection molding, toward the goal of Zero Defect Manufacturing (ZDM), with an emphasis on improving quality prediction methods through Artificial Intelligence (AI). It explores innovative strategies for improving the efficiency and quality of manufacturing processes, highlighting the importance of minimizing defects in industrial production.The research begins with an analysis of the current state of predictive quality systems in injection molding processes, identifying the critical need for advances to achieve ZDM. By collecting data from legacy and modern equipment, this work establishes a basis for a comprehensive analysis, using standard protocols and new methodologies for data collection. Central to this thesis is the application of feature selection algorithms, which employ a combination of filter, wrapper, embedded, and hybrid approaches. This framework is designed to accurately identify the key parameters that influence the quality of the injection molding process, thereby facilitating more effective and predictive modeling of manufacturing results. In addressing quality prediction, the thesis introduces both supervised and unsupervised models to predict manufacturing quality. It particularly focuses on enhancing these models with human knowledge, integrating expert insights into the predictive algorithms to better adapt to the complex dynamics of the manufacturing environment. This approach not only improves the accuracy of predictions but also enriches the models with practical, real-world applicability. Through a series of detailed use cases, the effectiveness of the proposed methodologies is demonstrated across various equipment and manufacturing scenarios. The results highlight significant improvements in process predictability, contributing to the reduction of defects and moving closer to the ideal of ZDM. The conclusion of this thesis reiterates the importance of its contributions to the field of AI used in production processes, with a focus on injection molding, providing a solid foundation for future research aimed at improving the integration of data-driven and human-centered approaches in manufacturing. The thesis outlines potential pathways for continued innovation in digitalization, feature selection, and quality prediction, emphasizing the ongoing pursuit of excellence in manufacturing processes.