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Machine learning applications in Intensive Care UnitSheikhalishahi, Seyedmostafa 28 April 2022 (has links)
The rapid digitalization of the healthcare domain in recent years highlighted the need for advanced predictive methods particularly based upon deep learning methods. Deep learning methods which are capable of dealing with time- series data have recently emerged in various fields such as natural language processing, machine translation, and the Intensive Care Unit (ICU). The recent applications of deep learning in ICU have increasingly received attention, and it has shown promising results for different clinical tasks; however, there is still a need for the benchmark models as far as a handful of public datasets are available in ICU. In this thesis, a novel benchmark model of four clinical tasks on a multi-center publicly available dataset is presented; we employed deep learning models to predict clinical studies. We believe this benchmark model can facilitate and accelerate the research in ICU by allowing other researchers to build on top of it. Moreover, we investigated the effectiveness of the proposed method to predict the risk of delirium in the varying observation and prediction windows, the variable ranking is provided to ease the implementation of a screening tool for helping caregivers at the bedside. Ultimately, an attention-based interpretable neural network is proposed to predict the outcome and rank the most influential variables in the model predictions’ outcome. Our experimental findings show the effectiveness of the proposed approaches in improving the application of deep learning models in daily ICU practice.
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Computational and Data-Driven Design of Perturbed Metal Sites for Catalytic TransformationsHuang, Yang 23 May 2024 (has links)
We integrate theoretical, computational and data-driven approaches for the sake of understanding, design and discovery of metal based catalysts. Firstly, we develop theoretical frameworks for predicting electronic descriptors of transition and noble metal alloys, including a physics model of d-band center, and a tight-binding theory of d-band moments to systematically elucidate the distinct electronic structures of novel catalysts. Within this framework, the hybridization of semi-empirical theories with graph neural network and attribution analysis enables accurate prediction equipped with mechanistic insights. In addition, novel physics effect controlling surface reactivity beyond conventional understanding is uncovered. Secondly, we develop a computational and data-driven framework to model high entropy alloy (HEA) catalysis, incorporating thermodynamic descriptor-based phase stability evaluation, surface segregation modeling by deep learning potential-driven molecular simulation and activity prediction through machine learning-embedded electrokinetic model. With this framework, we successfully elucidate the experimentally observed improved activity of PtPdCuNiCo HEA in oxygen reduction reaction. Thirdly, a Bayesian optimization framework is employed to optimize racemic lactide polymerization by searching for stereoselective aluminum (Al) -complex catalysts. We identified multiple new Al-complex molecules that catalyzed either isoselective or heteroselective polymerization. In addition, feature attribution analysis uncovered mechanistically meaningful ligand descriptors that can access quantitative and predictive models for catalyst development. / Doctor of Philosophy / In addressing the critical issues of climate change, energy scarcity, and pollution, the drive towards a sustainable economy has made catalysis a key area of focus. Computational chemistry has revolutionized our understanding of catalysts, especially in identifying and analyzing their active sites. Furthermore, the integration of open-access data and advanced computing has elevated data science as a crucial component in catalysis research. This synergy of computational and data-driven approaches is advancing the development of innovative catalytic materials, marking a significant stride in tackling environmental challenges. In my PhD research, I mainly work on the development of computational and data-driven methods for better understanding, design and discovery of catalytic materials. Firstly, I develop physics models for people to intuitively understand the reactivity of transition and noble metal catalysts. Then I embed the physics models into deep learning models for accurate and insightful predictions. Secondly, for a class of complex metal catalysts called high-entropy alloy (HEA) which is hard to model, I develop a modeling framework by hybridizing computational and data-driven approaches. With this framework, we successfully elucidate the experimentally observed improved activity of PtPdCuNiCo HEA in oxygen reduction reaction which is a key reaction in fuel cell technology. Thirdly, I develop a framework to virtually screen catalyst molecules to optimize polymerization reaction and provide potential candidates to our experimental collaborator to synthesize. Our collaboration leads to the discovery of novel high-performance molecular catalysts.
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