Abstract

Enhancing quadrotor efficiency through adaptive control is essential for addressing the crit- ical need for Fault-Tolerant Control (FTC) in the presence of operational uncertainties and component inefficiencies. Conventional adaptive FTC strategies typically assume that uncer- tainties are bounded by a constant known a priori. However, this assumption is inadequate when dealing with imprecise inertial system parameters, leading to state-dependent uncertain- ties that deviate from this model. When left unaddressed, such uncertainties can result in insta- bility, particularly under actuator faults, posing significant risks to the reliability of quadrotor systems. To overcome these challenges, the proposed adaptive FTC method effectively mitigates ac- tuator faults and addresses unknown state-dependent uncertainties through the implementation of carefully designed adaptive laws. This approach incorporates real-time fault detection and dynamic control allocation, which together prevent overly conservative control applications, ensuring that the quadrotor maintains optimal performance even under adverse conditions. By dynamically adjusting control efforts based on real-time data, the system is capable of respond- ing robustly to varying fault scenarios, thereby enhancing overall operational resilience. The stability of the closed-loop system is rigorously analyzed using Lyapunov theory, which provides a strong theoretical foundation for the proposed framework. Analytical studies con- firm that the adaptive FTC maintains stability across a wide range of operational scenarios, en- suring the quadrotor’s reliability. The effectiveness of this solution is further validated through comprehensive simulations on a realistic quadrotor model, demonstrating significant improve- ments over existing methods in terms of both stability and efficiency. This research highlights the importance of adaptive control strategies in maintaining reliable and safe quadrotor operations, setting the stage for future advancements in UAV fault tolerance and control systems. By addressing the complexities of state-dependent uncertainties and actu- ator faults, the study contributes to the broader field of autonomous aerial vehicles, ultimately enhancing the safety and effectiveness of UAV deployments in various applications.

Abstract

Music has therapeutic potential for individuals with Autism Spectrum Disorder (ASD). Traditional music therapy often lacks personalization, with music selected by therapists rather than tailored to individual preferences. Current studies on ASD individuals’ music preferences often overlook cultural inclusivity and the impact of lyrics. Moreover, existing recommendation systems do not consider music preferences tailored for therapeutic goals. This thesis explores how music aids emotional regulation, cognitive functioning, and social interaction in individuals with ASD, emphasizing cultural inclusivity. The study includes analyses of music specific community for neurotypical individuals (NT) and ASD communities on Reddit, cross-cultural comparisons between Non-Indian and Indian populations, a pilot study with Indian children with ASD, and the development of a personalized Music Recommendation System. Reddit analysis revealed diverse music preferences, underscoring the need for personalized interventions. Cross-cultural comparisons showed non-Indian participants preferred Rock and Western Classical music, while Indian participants favored Indian film and Devotional music, reflecting cultural influences on emotional expression. The pilot study with Indian children identified diverse music preferences, including Indian Devotional music, Nursery rhymes, and Indian film music. Listening to preferred music indicated positive behavioral changes, such as reduced anxiety and improved social interaction, highlighting music’s therapeutic potential. The GOAL (Genre, Optimization, Acoustic Features) based Music Recommendation System offers personalized suggestions based on genres, acoustic features, and lyrical themes relevant to emotional regulation, cognitive functioning, and social skills. By categorizing goals into emotional, cognitive, and social functions, the system aligns with diverse ASD needs and provides personalized music recommendations using similarity metrics. Evaluation metrics indicated the model accurately recommends relevant music, achieving a high proportion of liked music (precision) and capturing a significant portion of preferred music (recall). Behavioral changes showed effectiveness in mood management, focus, sensory load regulation, and sleep regularity, with mixed results in communication and social skills. In conclusion, this thesis underscores the importance of recognizing and accommodating ASD individuals’ music preferences in therapy. Despite limitations such as small sample sizes and subjective reports, findings offer insights into music’s therapeutic potential for ASD. Future research should include larger, diverse samples and longitudinal studies to enhance the proposed system’s effectiveness.

Abstract

Scene text conveys important information to drivers and pedestrians, serving as an indispensable means of communication in various environments. Scene text contains information regarding the speed limit, route information, rest stops, and exits, among other important information. It is important for drivers and passengers to understand this information for a safe and efficient journey. However, outdoor scenes are cluttered with text, distracting drivers and making it hard to focus on what matters, potentially compromising their ability to focus on essential details and navigate safely. Recognising scene text in motion aggravates this challenge, as textual cues transiently appear and necessitate early detection at a distance. Driving scenarios introduce additional complexities, including occlusions, motion blur, perspective distortions, and varying text sizes, further complicating scene text understanding. In this thesis, we look at improving scene text understanding in diving scenarios through video question answering and analysing the present state of scene text detection, recognition and tracking: (i) We introduce a new video questions answering task and dataset that requires an understanding of text and road signs in driving videos to answer the questions. (ii) We look at the current state of scene text detection, tracking and recognition in the driving domain through the RoadText-1K competition. (iii) We explore detection and recognition in special cases of occlusions, a common yet under-explored complication in real-world driving scenarios. By focusing on these areas, the thesis contributes to advancing scene text analysis methodologies, offering insights and solutions that are imperative for developing more intelligent and responsive driver assistance systems.

Abstract

This thesis addresses the critical challenge of monitoring water flow to support efficient water resource management and conservation. It presents an innovative approach to developing a sustainable water management system through an Internet of Things (IoT)-based solution. The primary objective is to retrofit existing analog water meters using affordable, off-the-shelf electronic components, transforming them into smart devices capable of real-time data collection and analysis. A distinctive feature of this system is its use of edge computation, which allows meter readings to be extracted directly from images captured by an onboard camera. This local processing approach minimizes latency and reduces the need for continuous cloud communication, enhancing system responsiveness and reducing data transmission costs. Energy efficiency and sustainability are critical components of this design. To support autonomous operation, the system is powered by solar-charged batteries, with strategies implemented to preserve charge-discharge cycles even in challenging environmental conditions. Additionally, an automated broadcasting technique facilitates firmware updates across multiple devices simultaneously, reducing the need for manual intervention and enhancing overall maintenance efficiency. The effectiveness and reliability of the system were validated through an extensive field deployment involving 15 smart water meter nodes installed across various locations at IIIT-H campus and monitored continuously for over 2.5 years. This long-term deployment provided valuable real-world data, allowing for detailed characterization of water usage patterns across different environments. The stable operation of these nodes over a prolonged period demonstrated the robustness and durability of the design, supporting its potential for broader application in diverse settings. An essential feature of the system is its energy-harvesting capability, which minimizes reliance on external power sources and significantly reduces maintenance requirements. This feature aligns with sustainable energy practices and promotes an eco-friendly approach to water resource management. By integrating efficient data acquisition, local processing, and cloud-based storage and analysis, this IoTbased solution offers a comprehensive, scalable, and sustainable approach to advancing water resource management and supporting global conservation efforts.

Abstract

Integrating Artificial Intelligence (AI) into drug design has revolutionized the field at various levels, ranging from simple molecular property prediction tasks to complex de novo drug design tasks. This is still a relatively young field and is rapidly evolving. In this thesis, we identify various challenges AI models face due to data constraints and analyze hidden biases in these methods; we improve upon existing molecular generation models for aligning the drug design to desired complex properties; we propose a novel framework for structure elucidation from molecular spectra. The second chapter explores various biases in protein-ligand datasets that affect the performance of deep learning models in binding affinity prediction and virtual screening. It demonstrates how random data splitting leads to overly optimistic results and introduces more nuanced data splitting methods that account for sequence, pocket structure, and protein-ligand interaction similarities. The research identifies biases in these datasets related to protein-only and ligand-only information. It proposes improvements in dataset construction and model design to enhance the generalizability and accuracy of AI-based protein-ligand scoring functions. In the third chapter, we develop and refine Molecular generative models for more accurate conditional generation. We propose optimization methods aligning the generated molecules’ properties with the desired ones. The fourth chapter introduces the Spectra and Molecule Encoder Network (SMEN) for scoring molecules against target spectra. The model aims to aid library ranking tasks for Infrared (IR) Spectrumbased structure elucidation. SMEN learns spectral and molecular embeddings, accurately representing both entities in a high-dimensional latent space. Additionally, the SMILES Decoder (SD) generates SMILES strings from the latent space, enabling accurate one-shot predictions from IR spectra to molecule structures and showcasing promising accuracies for rapid, precise structure elucidation. In summary, This thesis explores the potential of ML models to predict binding affinities and generate molecular structures with desired properties. It begins by identifying and addressing latent biases in popular protein-ligand datasets, affecting binding affinity predictions’ accuracy. This research introduces more refined data-splitting methods that enhance model generalizability by analyzing biases in sequence-based and structure-based datasets. The thesis then presents a generative model for generating molecules with specific characteristics, such as binding affinity, and further optimizes the model’s ability to produce molecules that meet predefined criteria. Lastly, a contrastive learning framework is developed for generating molecular structures from infrared spectra, demonstrating the model’s versatility in handling various molecular generation tasks. Each chapter addresses foundational issues, setting the stage for future innovations in the field.

Abstract

This research delves into the application of advanced semantic segmentation techniques to automate facade inspection, a critical component in the maintenance and safety assessment of urban infrastruc- tures. Central to the study is the WALL-E dataset, a comprehensive collection specifically curated to encompass a wide range of facade defects, including cracks, stains, and delamination. This dataset is designed to challenge and refine the capabilities of deep learning models by exposing them to a diverse array of defect types and complex architectural features, thereby mimicking the variety of conditions encountered in real-world settings. The training methodology employed in this study leverages the strengths of the DeepLabV3+ model, compared against other leading models such as UNet, PSPNet, and FCN. Each model was rigorously trained and evaluated on their ability to accurately segment defects across different types of building materials and architectural styles. DeepLabV3+ emerged as the standout model due to its sophisticated architecture that combines atrous convolution with an encoder-decoder structure, enhancing its ability to capture detailed spatial information and accurately delineate defect boundaries. A significant portion of the evaluation focused on the generalization capabilities of the models. DeepLabV3+ demonstrated remarkable adaptability, not only performing well on the diverse images of the WALL-E dataset but also showing robust generalization on arbitrary internet images and out-of- distribution samples. This indicates the model’s ability to extend beyond its training parameters and adapt to new, unseen scenarios, which is essential for practical applications where variable conditions are common. Further assessments were made on images without defects to evaluate the model’s precision in iden- tifying defect-free areas, thereby reducing the likelihood of false positives. This aspect of the model’s performance is critical in practical scenarios, where the ability to distinguish between damaged and intact structures can significantly impact maintenance decisions and safety assessments. This thesis highlights the significant potential of using semantic segmentation in the realm of struc- tural health monitoring. The advanced capabilities of DeepLabV3+, coupled with the comprehensive and diverse WALL-E dataset, set a new benchmark in the field, providing a strong foundation for future research and practical applications in facade inspection. This work not only advances the technology in automated building inspections but also opens up new avenues for further enhancements and applica- tions in urban infrastructure maintenance.

Abstract

Federated learning offers a promising approach to learn collaboratively across multiple devices or agents. This collaboration allows leveraging a vast amount of data while preserving privacy by keeping the raw data local. However, this approach is not void of challenges. This thesis explores some of these challenges in the context of multi-armed bandit (MAB) problems. MAB problems are a type of decision-making problem where an agent repeatedly chooses between multiple actions, each with an unknown reward, and aims to maximize the total reward over time. Federated MABs introduce unique fairness concerns. For instances, for a fair algorithm, the learning process should not favor certain actions over others to an extreme degree, especially if those actions are beneficial to specific sub-populations. In addition to fairness, privacy is another key challenge. While federated learning avoids sharing raw data, the learning process itself can leak information about individual data points. This thesis proposes two novel algorithms (and variants) to address these challenges. The first algorithm, P-FCB, tackles a specific type of MAB problem with constraints in a federated setting. It promotes fairness by optimizing for the collective benefit of all users. The second algorithm, Fed-FairX-LinUCB, focuses on achieving fairness and privacy guarantees in a more complex scenario where actions have additional context. It ensures that action selection is fair and avoids situations where some actions are never chosen. Additionally, both these algorithms provide differential privacy guarantees, a formal guarantee that ensures the learning process reveals minimal information about any individual data point. By exploring these algorithms, this thesis aims to contribute to the development of federated learning for MAB problems that is both fair and privacy-preserving.

Abstract

Sleep plays a critical role in maintaining overall health and well-being, impacting both psychological and physiological functions. However, sleep disorders such as insomnia, obstructive sleep apnea (OSA), and narcolepsy are becoming increasingly prevalent, significantly affecting individual’s quality of life. Effective sleep stage classification is essential for diagnosing and treating these disorders. Traditional methods like polysomnography (PSG) are the gold standard for diagnosing sleep disorders, but they are expensive, cumbersome, and not easily accessible due to the need for specialized equipment and trained personnel. Moreover, PSG relies heavily on electroencephalogram (EEG) data, which, despite its effectiveness, presents practical challenges in non-clinical settings due to the complexity of electrode placement and patient discomfort. Innovative strategies in wearable technology using supervised deep learning techniques offer a promising alternative for enhancing sleep stage classification, making it more accessible and user-friendly. This work aims to overcome these limitations by exploring the potential of using electrooculogram (EOG) signals for sleep stage classification. EOG signals, which are non-invasive and can be more easily integrated into wearable technology, offer a promising alternative for long-term sleep monitoring and provide a more comfortable experience for patients. The core contribution of this research is the design and implementation of a novel SE-ResNet-Transformer model. This model architecture combines the strengths of Squeeze-and-Excitation Residual Networks (SE-ResNet) and Transformer encoders, tailored to handle the unique characteristics of EOG signals. The SE-ResNet component enhances feature extraction by adaptively recalibrating feature responses, allowing the model to focus on the most informative aspects of the EOG signal. The Transformer encoder component captures the temporal dependencies within the EOG signals, enabling the model to understand the dynamic transitions between sleep stages. The performance of the SE-ResNet-Transformer model was rigorously evaluated using three publicly available datasets—SleepEDF-20, SleepEDF-78, and SHHS. The model demonstrated superior accuracy and robustness across different datasets, with its EOG-based performance comparable to models trained with EEG data. This suggests that EOG is a viable alternative for sleep monitoring, particularly relevant for the development of wearable technology. Extensive ablation studies were conducted to fine-tune the model’s parameters and configurations, providing valuable insights into optimal settings for window sizes and strides, and enhancing the model’s efficiency and performance. Techniques like 1D-Gradient-weighted Class Activation Mapping (Grad-CAM) and t-distributed Stochastic Neighbor Embedding (t-SNE) plots were employed to visualize the model’s decision-making process, emphasizing transparency and interpretability. In addition, this work introduces the pioneering Indian SLEEP dataset of ischemic Stroke patients (iSLEEPS) which addresses a gap in the availability of India-specific sleep disorder data, with a particular focus on the impact of ischemic stroke on sleep health. This dataset is comprehensive, including detailed clinical annotations that cover patient demographics, diagnoses, and sleep stages. Cutting-edge deep learning models, including CNN-based, LSTM-based, and Transformer-based architectures, were trained on raw single-channel EEG and EOG signals. Among these, the Transformer-based model showed remarkable performance in sleep stage classificatzions using single-channel EOG data. The successful validation of these models on the iSLEEPS highlights their potential to enhance diagnostic tools and therapeutic strategies, thereby contributing to improved patient outcomes and fostering global collaboration in sleep research. In conclusion, this thesis presents advancements in the field of automated sleep stage classification using wearable technology and supervised deep learning. By leveraging EOG signals and deep learning architectures, this research offers promising solutions for more accessible, accurate, and comfortable sleep monitoring, ultimately aiming to bridge the gap between clinicalgrade sleep monitoring and everyday health management tools, thus enhancing sleep health and overall wellness

Abstract

The strategic application of artificial intelligence (AI) in healthcare has the potential to revolutionize patient care, particularly in the domains of public health and cardiology. This thesis presents innovative AI-based solutions to address critical challenges in these fields, focusing on enhancing decision-making, disease surveillance, and diagnostic accuracy. In the second chapter, we introduce the AI-Based Home-Based Care Assistive System (AI-HBCAS), developed to aid healthcare professionals in identifying severe patient conditions that require referrals. By analyzing patient demographics, symptoms, and vital signs, AI-HBCAS enhances clinical decision- making, ensuring timely and appropriate care for patients with non-communicable diseases (NCDs). This system aligns with the Ministry of Health and Family Welfare’s goals of improving public health delivery through digital health solutions. The third chapter explores the development of a Pharmaco- surveillance model for outbreak detection and awareness in Primary Health Centers (PHCs). Leveraging AI, we try to analyse prescriptions and pharmacy records to map drug utilization patterns and detect lo- cal outbreaks. The insights generated could potentially support timely public health interventions and contribute to the Ministry of Health and Family Welfare’s objectives of enhancing public health infras- tructure and outcomes. We then delve into the development of a unique deep learning architecture for heart murmur detection using phonocardiogram (PCG) recordings in chapter four. Our modified variable kernel length Resid- ual Networks (ResNets) demonstrate significant improvements in detecting heart murmurs, achieving a weighted accuracy score of 0.708 in the George B. Moody PhysioNet Challenge 2022. This inno- vative approach highlights the potential of deep learning models in improving diagnostic accuracy in cardiology, specifically using audio modalities. Chapter five focuses on the creation of a machine learn- ing approach for predicting outcomes in post-anoxic coma patients using longitudinal EEG and ECG recordings. Our model extracts frequency domain features from these recordings, combining them with demographic data to predict neurological recovery following cardiac arrest. This solution, part of the George B. Moody PhysioNet Challenge 2023, underscores the viability of machine learning models in critical care settings, offering valuable prognostic insights.

Abstract

This thesis explores and analyzes humor generation through several methods. This thesis introduces an approach to automated joke generation that leverages a novel hybrid model combining template extraction and infilling. Recognizing the inherent structure and unpredictability in humor, this work pi- oneers a method that extracts templates from existing jokes and subsequently infills these templates with new content, guided by state-of-the-art (SOTA) techniques available at the time of research. Specifically, the thesis accomplishes three main objectives: Firstly, it develops an automated system for joke genera- tion that innovatively combines template extraction with a deep learning approach for content infilling, ensuring both the preservation of joke structure and the introduction of novelty. This approach uses a rule-based method to extract a template from a joke and then infills it using BERT. Secondly, it extends the base model by incorporating advancements in language models and natural language processing to enhance the flexibility and quality of generated jokes, broadening the scope of humor that the system can produce. This approach uses a novel strategy to identify semantically salient words, and uses LLMs on top of earlier models for the infilling. Lastly, the thesis explores a distinct avenue in humor genera- tion by employing conversational prompts within a conversational AI framework with GPT-4, the SOTA at the time of presentation. This method not only diversifies the ways in which humor can be generated but also reflects on the potential of conversational AI to contribute creatively to the domain of humor. Through rigorous evaluation, this work demonstrates the efficacy of the proposed methods in generating humor that is coherent, contextually appropriate, and, most importantly, funny. This research not only contributes a novel technique to the field of computational humor but also opens up new pathways for future exploration in automated joke generation and the creative capacities of AI.