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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

EDGE COMPUTING APPROACH TO INDOOR TEMPERATURE PREDICTION USING MACHINE LEARNING

Hyemin Kim (11565625) 22 November 2021 (has links)
<p>This paper aims to present a novel approach to real-time indoor temperature forecasting to meet energy consumption constraints in buildings, utilizing computing resources available at the edge of a network, close to data sources. This work was inspired by the irreversible effects of global warming accelerated by greenhouse gas emissions from burning fossil fuels. As much as human activities have heavy impacts on global energy use, it is of utmost importance to reduce the amount of energy consumed in every possible scenario where humans are involved. According to the US Environmental Protection Agency (EPA), one of the biggest greenhouse gas sources is commercial and residential buildings, which took up 13 percent of 2019 greenhouse gas emissions in the United States. In this context, it is assumed that information of the building environment such as indoor temperature and indoor humidity, and predictions based on the information can contribute to more accurate and efficient regulation of indoor heating and cooling systems. When it comes to indoor temperature, distributed IoT devices in buildings can enable more accurate temperature forecasting and eventually help to build administrators in regulating the temperature in an energy-efficient way, but without damaging the indoor environment quality. While the IoT technology shows potential as a complement to HVAC control systems, the majority of existing IoT systems integrate a remote cloud to transfer and process all data from IoT sensors. Instead, the proposed IoT system incorporates the concept of edge computing by utilizing small computer power in close proximity to sensors where the data are generated, to overcome problems of the traditional cloud-centric IoT architecture. In addition, as the microcontroller at the edge supports computing, the machine learning-based prediction of indoor temperature is performed on the microcomputer and transferred to the cloud for further processing. The machine learning algorithm used for prediction, ANN (Artificial Neural Network) is evaluated based on error metrics and compared with simple prediction models.</p>
2

On Non-Convex Splitting Methods For Markovian Information Theoretic Representation Learning

Teng Hui Huang (12463926) 27 April 2022 (has links)
<p>In this work, we study a class of Markovian information theoretic optimization problems motivated by the recent interests in incorporating mutual information as performance metrics which gives evident success in representation learning, feature extraction and clustering problems. In particular, we focus on the information bottleneck (IB) and privacy funnel (PF) methods and their recent multi-view, multi-source generalizations that gain attention because the performance significantly improved with multi-view, multi-source data. Nonetheless, the generalized problems challenge existing IB and PF solves in terms of the complexity and their abilities to tackle large-scale data. </p> <p>To address this, we study both the IB and PF under a unified framework and propose solving it through splitting methods, including renowned algorithms such as alternating directional method of multiplier (ADMM), Peaceman-Rachford splitting (PRS) and Douglas-Rachford splitting (DRS) as special cases. Our convergence analysis and the locally linear rate of convergence results give rise to new splitting method based IB and PF solvers that can be easily generalized to multi-view IB, multi-source PF. We implement the proposed methods with gradient descent and empirically evaluate the new solvers in both synthetic and real-world datasets. Our numerical results demonstrate improved performance over the state-of-the-art approach with significant reduction in complexity. Furthermore, we consider the practical scenario where there is distribution mismatch between training and testing data generating processes under a known bounded divergence constraint. In analyzing the generalization error, we develop new techniques inspired by the input-output mutual information approach and tighten the existing generalization error bounds.</p>
3

A Systems Engineering Analysis of Opportunities for Pharmacists on Diabetes Care Teams

Michelle A Jahn (6485252) 15 May 2019 (has links)
<p>Diabetes is one of the most significant global healthcare challenges of the 21st century: it is estimated that one in three adults will have diabetes in the United States in the year 2050. As a result, healthcare organizations are integrating systemic changes to address the needs of expanding chronic care patient population, including shifting towards a patient-centered medical home philosophy and introducing new health information technology tools to help share the workload for diabetes care activities. Advanced educational opportunities, collaborative-practice agreements, and a shifting model towards community-based care clinics affords opportunities for pharmacy professionals to participate in a more central role on the diabetes care team.</p><p><br></p> <p> </p> <p>This dissertation work explores the intersection of diabetes care coordination and health information technology (IT), with a specific focus on the potential for pharmacist involvement on the diabetes care team. Studies I and II aimed to define the existing diabetes care team as a system, with identifying the specific roles, information flows, tasks, and temporal and geospatial attributes for providing effective care. Study I used a questionnaire and social network analysis tools to identify the key members of the diabetes care team. The results indicated that these team members were the primary care provider, endocrinologist, nurse, pharmacist, dietitian, and social worker. Study II used semi-structured interviews and team task analysis for thirty (N=30) diabetes care team member participants (N=5 for each category indicated in Study I). The results from Study II led to the creation of a new systems engineering analytical framework, titled Diabetes care Roles Information Flows and Team Coordination (DRIFT). This framework expanded existing chronic care and healthcare systems engineering frameworks through the inclusion of granularity, temporal, and sociotechnical factors in a three-dimensional systems model. Study II also provided confirmatory support for the inclusion of pharmacists for sharing more care coordination activities on diabetes care teams.</p> <p><br></p> <p>The results from studies I and II were synthesized to identify potential engineering health IT solutions to gaps in diabetes care activities. The results synthesis was the foundation of a new health IT system prototype, eVincio, developed by the author for this dissertation work. eVincio is comprised of a patient-facing mobile application and a provider-facing desktop software that worked together to help healthcare professionals visualize patient care activities via the DRIFT analytical framework. Study III was a formative usability assessment of the eVincio prototypes with six (N=6) pharmacist participants. Results revealed that eVincio could be very beneficial for helping healthcare professionals visualize patient care activities and identify gaps in care coordination, particularly for professionals who work as case managers, population health analysts, or have some aspect of quality monitoring in their role. As the eVincio system is still in a prototype stage of development, additional studies need to be conducted to determine system requirements for interoperability, evidence-based guidelines, and fulfilling end-user requirements.</p>
4

Network Utility Maximization Based on Information Freshness

Cho-Hsin Tsai (12225227) 20 April 2022 (has links)
<p>It is predicted that there would be 41.6 billion IoT devices by 2025, which has kindled new interests on the timing coordination between sensors and controllers, i.e., how to use the waiting time to improve the performance. Sun et al. showed that a <i>controller</i> can strictly improve the data freshness, the so-called Age-of-Information (AoI), via careful scheduling designs. The optimal waiting policy for the <i>sensor</i> side was later characterized in the context of remote estimation. The first part of this work develops the jointly optimal sensor/controller waiting policy. It generalizes the above two important results in that not only do we consider joint sensor/controller designs, but we also assume random delay in both the forward and feedback directions. </p> <p> </p> <p>The second part of the work revisits and significantly strengthens the seminal results of Sun et al on the following fronts: (i) When designing the optimal offline schemes with full knowledge of the delay distributions, a new <i>fixed-point-based</i> method is proposed with <i>quadratic convergence rate</i>; (ii) When the distributional knowledge is unavailable, two new low-complexity online algorithms are proposed, which provably attain the optimal average AoI penalty; and (iii) the online schemes also admit a modular architecture, which allows the designer to <i>upgrade</i> certain components to handle additional practical challenges. Two such upgrades are proposed: (iii.1) the AoI penalty function incurred at the destination is unknown to the source node and must also be estimated on the fly, and (iii.2) the unknown delay distribution is Markovian instead of i.i.d. </p> <p> </p> <p>With the exponential growth of interconnected IoT devices and the increasing risk of excessive resource consumption in mind, the third part of this work derives an optimal joint cost-and-AoI minimization solution for multiple coexisting source-destination (S-D) pairs. The results admit a new <i>AoI-market-price</i>-based interpretation and are applicable to the setting of (i) general heterogeneous AoI penalty functions and Markov delay distributions for each S-D pair, and (ii) a general network cost function of aggregate throughput of all S-D pairs. </p> <p> </p> <p>In each part of this work, extensive simulation is used to demonstrate the superior performance of the proposed schemes. The discussion on analytical as well as numerical results sheds some light on designing practical network utility maximization protocols.</p>
5

3D OBJECT DETECTION USING VIRTUAL ENVIRONMENT ASSISTED DEEP NETWORK TRAINING

Ashley S Dale (8771429) 07 January 2021 (has links)
<div> <div> <div> <p>An RGBZ synthetic dataset consisting of five object classes in a variety of virtual environments and orientations was combined with a small sample of real-world image data and used to train the Mask R-CNN (MR-CNN) architecture in a variety of configurations. When the MR-CNN architecture was initialized with MS COCO weights and the heads were trained with a mix of synthetic data and real world data, F1 scores improved in four of the five classes: The average maximum F1-score of all classes and all epochs for the networks trained with synthetic data is F1∗ = 0.91, compared to F1 = 0.89 for the networks trained exclusively with real data, and the standard deviation of the maximum mean F1-score for synthetically trained networks is σ∗ <sub>F1 </sub>= 0.015, compared to σF 1 = 0.020 for the networks trained exclusively with real data. Various backgrounds in synthetic data were shown to have negligible impact on F1 scores, opening the door to abstract backgrounds and minimizing the need for intensive synthetic data fabrication. When the MR-CNN architecture was initialized with MS COCO weights and depth data was included in the training data, the net- work was shown to rely heavily on the initial convolutional input to feed features into the network, the image depth channel was shown to influence mask generation, and the image color channels were shown to influence object classification. A set of latent variables for a subset of the synthetic datatset was generated with a Variational Autoencoder then analyzed using Principle Component Analysis and Uniform Manifold Projection and Approximation (UMAP). The UMAP analysis showed no meaningful distinction between real-world and synthetic data, and a small bias towards clustering based on image background. </p></div></div></div>

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