Doctoral School

Reading date: 10/12/2025

• KHABBAZAN, BAHAREH: Improving Memory-centric Architectures for Accelerating Cognitive Computing Workloads
  
  Author: KHABBAZAN, BAHAREH
  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: 31/10/2025
  Reading date: 10/12/2025
  Reading time: 15:00
  Reading place: Sala d'actes - Edif. B6 – Planta 0
  Thesis director: RIERA VILLANUEVA, MARC | GONZÁLEZ COLÁS, ANTONIO MARIA
  Thesis abstract: The rapid advancements in deep neural networks (DNNs) have led to increasingly complex and memory-intensive workloads, posing significant challenges for traditional computing architectures. Excessive data movement, computational inefficiencies, and energy constraints limit the scalability of DNN accelerators. This thesis addresses these challenges by proposing memory-centric approaches to optimize DNN execution through efficient quantization, in-memory processing, and data movement reduction.We first introduce DNA-TEQ, an adaptive exponential quantization scheme that minimizes memory footprint and eliminates the need for conventional multipliers, significantly enhancing energy efficiency. Experimental results show that DNA-TEQ reduces the memory footprint by 40% on average compared to the 8-bit integer baseline. The hardware processing-near-memory (PnM) accelerator designed to benefit from DNA-TEQ further improves inference latency by 1.5× while maintaining accuracy comparable to full-precision models.Next, we present QeiHaN, a PnM accelerator that employs base-2 exponential quantization and an implicit bit-shifting technique to reduce redundant memory accesses and optimize DNN inference. Our evaluations demonstrate that QeiHaN reduces memory movement by 67%, leading to a 4.2× speedup in execution time and a 3.5× reduction in energy consumption compared to conventional baseline architectures.Lastly, we propose Lama, a lightweight memory access mechanism that enhances lookup table (LUT)-based processing-in-memory (PuM) architectures by enabling parallel, column-independent accesses within DRAM mats, supporting up to 8-bit integer SIMD operations for large-scale models. The experimental results show that Lama significantly reduces memory commands for SIMD operations compared to the state-of-the-art PuM techniques. We further leverage Lama to design LamaAccel, an HBM-based large language model (LLM) accelerator that executes efficiently without modifying DRAM timing parameters. LamaAccel outperforms GPUs by up to 19×, achieving substantial energy savings in low-precision layers.The proposed techniques collectively reduce data movement, optimize memory utilization, and improve computational efficiency. Our findings demonstrate that memory-centric approaches can significantly enhance DNN acceleration, offering scalable and energy-efficient solutions for next-generation AI systems.
  

Reading date: 11/12/2025

• CRIOLLO ALIENDRES, CRUZ ARMANDO: Caracas Cinética: La transformación del paisaje urbano a partir de la inserción de obras de arte en los edificios públicos y privados, en los espacios públicos, la infraestructura vial y los sistemas masivos de transporte 1950-2012.
  
  Author: CRIOLLO ALIENDRES, CRUZ ARMANDO
  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: 29/09/2025
  Reading date: 11/12/2025
  Reading time: 15:30
  Reading place: ETSAB (Esc. Técnica Sup. Arquit. Bcn)-Pl.Baja-Sala GradosAv. Diagonal, 649-651-08028-BCN(Videoconfencia: https://meet.google.com/ckz-quih-zjk-15:00)
  Thesis director: RUBERT DE VENTOS, MARIA
  Thesis abstract: This thesis analyzes the role of public art in the symbolic and social transformation of urban space in Caracas, with special emphasis on its transformative potential in environments marked by spatial fragmentation and a lack of public space. It is based on the premise that public art—particularly murals, sculptures, visual interventions, and ephemeral installations—intervenes in the relationships between citizens, territory, and collective memory.The research is based on a dual quantitative and qualitative approach, which articulates urban history, the cataloging and study of unique cases located in different urban environments (buildings, road infrastructure, the Metro, and the street), as well as an urban analysis from the 1950s to 2010. Emblematic cases are analyzed, such as works of art integrated into architecture, interventions linked to the network of avenues and highways, and monumental works such as those by Gego, Carlos Cruz Diez, Jesús Soto, and Alejandro Otero.The findings reveal that public art in Caracas serves multiple functions: it redefines urban spaces, reinforces local and metropolitan identities, and democratizes access to culture. The research identifies how the recurring practice of integrating art, architecture, and the city has evolved into an urban tradition that continues to this day, in an environment that poses tensions between visual art, urban policies, and the processes of appropriation of public space. Thus, art located in urban spaces plays a connecting role between institutional programs and social actors.Finally, the thesis compiles and organizes a section of the city's urban evolution, in which public art served as a catalyst for a more just, plural, and participatory city.
  

• DEL POZO MARTÍN, JORGE: Estudio estadístico del control de calidad del hormigón
  
  Author: DEL POZO MARTÍN, JORGE
  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: 18/11/2025
  Reading date: 11/12/2025
  Reading time: 10:00
  Reading place: C1-002
  Thesis director: AGUADO DE CEA, ANTONIO | PIALARISSI CAVALARO, SERGIO HENRIQUE
  Thesis abstract: This doctoral thesis addresses a critical analysis of the structural concrete quality control system in Spain. Currently, national regulations establish a dual control system: one for production, executed by the manufacturer at the plant, and another for reception, carried out on-site upon receipt of the concrete. This duplication generates operational, technical, and economic conflicts, as well as potential inconsistencies in test results, which raises a debate about its suitability and effectiveness.The general objective of the first part of this thesis is to evaluate the efficiency and reliability of the dual control system, in order to subsequently propose an optimized model that simplifies the process without compromising structural safety or concrete quality. The aim is to move toward a more rational control adapted to the technological reality and European regulations.The second line of research focuses on the statistical basis on which the regulatory criteria for the acceptance or rejection of a batch of concrete are based. Currently, Spanish regulations assume that compression test results follow a normal (Gaussian) distribution. However, this hypothesis lacks solid theoretical justification and has limitations such as the possibility of obtaining negative values and a symmetry that does not always fit the real data. Therefore, other distribution functions are explored, such as the log-normal and Weibull distribution functions, which could better fit the actual results obtained in tests.Throughout the document, a methodology based on the analysis of large volumes of test data from real-life construction projects is presented. Different distribution functions are contrasted using goodness-of-fit tests, and the differences in the estimate of the 5% percentile, which defines the characteristic strength of concrete, are quantified. The results indicate that the normal function is not the most appropriate distribution function to best fit the data.Based on the findings obtained, the thesis proposes a review of the current quality control model, opting for a system based primarily on production control—with the possibility of receiving control using other types of tests that provide information about the finished structure—provided that traceability and quality are guaranteed through strict procedures and certifications. Likewise, it is suggested that normative statistical models be updated, incorporating distribution functions that more accurately represent the actual behavior of concrete.In conclusion, this research proposes a significant improvement in the way structural concrete quality is controlled in Spain. It provides technical, regulatory, and statistical foundations that justify a shift toward a more efficient model, free of redundancies, aligned with European guidelines, and supported by more robust statistical analysis, which could represent
  

• FERRANDO MONSONÍS, JAVIER: Interpretability in Natural Language Processing and Machine Translation
  
  Author: FERRANDO MONSONÍS, 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 ARTIFICIAL INTELLIGENCE
  Department: Department of Computer Science (CS)
  Mode: Normal
  Deposit date: 13/11/2025
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: RUIZ COSTA-JUSSA, MARTA
  Thesis abstract: This thesis presents a set of methods and analyses designed to improve our understanding of the internal mechanisms of Transformer-based models in natural language processing and machine translation.This work first investigates the role of attention weights in encoder-decoder Transformers, showing that while they do not provide accurate word alignments, they nonetheless help explain model predictions and contribute to a deeper understanding of translation quality.A central contribution of the dissertation is the development of ALTI and its extensions, which offer a new approach to input attribution. These methods challenge prior assumptions about the explanatory power of attention mechanisms and reveal how information propagates between encoder and decoder components. In doing so, they also shed light on sources of hallucinations in translation systems.Further, the thesis introduces techniques to attribute predictions to individual components and positions, enabling contrastive explanations of linguistic behavior. These explanations clarify how language models represent and solve different linguistic phenomena.The dissertation also proposes a methodology for tracking information flow during inference, offering insight into how various components contribute to model predictions. This allows for the identification of domain-specialized components and a better understanding of how representations are transformed across layers.Lastly, the analysis of cross-lingual circuit similarities reveals shared structural patterns in how models handle different languages. These findings point to potential universal mechanisms in language models.Collectively, this thesis advances the interpretability of Transformer models by providing tools and frameworks for probing, attributing, and understanding the behavior of complex NLP systems.
  

• LÓPEZ GÓMEZ, PATRICIA VICTORIA: Multifunctional hydrogels for advanced regenerative therapies
  
  Author: LÓPEZ GÓMEZ, PATRICIA VICTORIA
  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 Materials Science and Engineering (CEM)
  Mode: Normal
  Deposit date: 19/09/2025
  Reading date: 11/12/2025
  Reading time: 10:30
  Reading place: Aula A1.13, Edifici A, Escola d'Enginyeria de Barcelona Est (EEBE), Av. d'Eduard Maristany, 16, 08019 Barcelona
  Thesis director: MAS MORUNO, CARLOS | MEHWISH, NABILA
  Thesis abstract: Implant-associated infections remain one of the most critical challenges in the biomedical field. Despite advances in aseptic surgical techniques and antibiotic therapies, the persistence of bacterial colonization on implant surfaces -often involving biofilm formation- continues to compromise clinical outcomes. Conventional treatment strategies, including the systemic administration of antibiotics, local drug delivery systems, and surgical debridement, often fail to effectively eradicate biofilms, particularly those formed by pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. Concurrently, the field of tissue engineering demands implantable materials that not only support tissue regeneration but also provide active defense against infection. However, most currently available materials fall short of achieving this dual function. In contaminated or high-risk environments, this shortcoming becomes especially critical. To address these limitations, there has been a growing focus on developing next-generation biomaterials that are no longer passive scaffolds but bioactive and dynamic systems capable of interacting with the biological milieu in real time. In this context, biofunctionalization has emerged as a powerful strategy to enhance both regenerative and antimicrobial properties of biomaterials. Among the different bioactive tools available, peptides have shown considerable promise due to their tunable chemistry, modular architecture, and high specificity. This thesis focuses on two peptide motifs with complementary bioactivities: RGD, which promotes cell adhesion, and hLf1-11, a broad-spectrum antimicrobial peptide derived from human lactoferrin. Together, these peptides represent a rational platform for engineering multifunctional materials that address the dual challenge of infection control and tissue integration. Specifically, the present work investigates the integration of RGD and hLf1-11 peptides into three hydrogel-based material systems, each representing a distinct level of biofunctionality and design complexity: • Chapter I examines the modification of alginate, a naturally derived but bioinert polymer, with RGD-hLf1-11 to evaluate stem cell behavior and antimicrobial activity. • Chapter II explores a fully synthetic PEG-based hydrogel system functionalised with these peptides and incorporating a protease-sensitive crosslinker to enable bioactivity and controlled degradation. • Chapter III focuses on self-assembling peptide hydrogels, where both structural assembly and biological function are encoded at the molecular level, enabling the formation of intrinsically bioactive materials without further modification. Collectively, these platforms offer a comparative and progressive approach toward the design of multifunctional hydrogels. This work not only demonstrates the feasibility of dual viii biofunctionalization but also highlights the critical roles of molecular architecture, crosslinking strategy, and material origin in shaping biological responses. Ultimately, this thesis contributes to the development of smart biomaterials that are both cell-instructive and antibacterial, aligning with the growing clinical need for adaptable, multifunctional solutions in regenerative medicine and infection-prone environments.