Digital Commons Network^™

Incremental Cluster Validity Indices And Their Role In Interpreting Lifelong Learning Systems, Niklas Max Melton

Doctoral Dissertations

Clustering and supervised learning are often treated as distinct paradigms, yet both rely on structure in feature space. This dissertation investigates the relationship between cluster validity indices (CVIs) and supervised learning in real-time and lifelong learning settings where data arrive incrementally and cannot be revisited. Across four studies, it develops methods for online cluster validation, uses supervised learning to improve their interpretability, and applies these ideas to evaluating performance degradation in continual learning.

The first study extends incremental cluster validity indices (iCVIs), enabling widely used validation metrics to operate in streaming environments. Experiments on synthetic and real-world datasets show systematic …

Critical Parameters Controlling Oxide Scale Formation And Hydro-Descaling Efficiency During Steelmaking, Tochukwu Princewill Ojiako

Doctoral Dissertations

In modern steelmaking, cast slabs are exposed to high-temperature oxidizing environments during secondary cooling, reheating, and hot rolling, resulting in the formation of multilayer oxide scales on the steel surface. These scales interact with mold-flux residues originating from the casting process (CC). The morphology, chemistry, and adhesion of oxide scale strongly influence its removability during high-pressure hydraulic descaling and ultimately determine the surface quality of hot-rolled products. However, the mechanistic relationship between oxide scale evolution, scale-steel interfacial structure, and hydraulic descaling performance remains poorly understood.

This dissertation investigates oxide scale formation, modification, and removal in low-carbon thin-slab steels produced by …

Probability Of Detection For Corrosion-Induced Mass Loss And Yield Strain In Metal Structures Using Fe-C Coated Long Period Fiber Gratings Sensors And Electroresistive Strain Gauges, Ying Zhuo

Doctoral Dissertations

"Graphene-based, Fe-C coated long-period fiber grating (LPFG) sensors individually reveal a causal relation between LPFG wavelength change and Fe-C mass loss. Their correlation parameters vary significantly between the sensors mainly because hydrophobic multilayer graphene and graphene oxide make sensor fabrication inconsistent. This study explores MXene-based, Fe-C coated LPFG sensors due to MXene’s inherent hydrophilic property in the presence of surface functional groups such as hydroxyl and oxygen and the probability of detection (POD) for mass loss from Fe-C coated LPFG sensors when deployed at a fixed location. A novel fabrication process incorporating Piranha solution pretreatment is proposed to ensure uniform …

Milankovitch Paleoclimatic Signals In Upper Permian–Lower Triassic Fluvial-Lacustrine Records, Bogda Mountains, Greater Turpan-Junggar Intracontinental Rift Basin, Nw China, Wentao Zhang

Doctoral Dissertations

"The objective of this study is to understand whether Milankovitch climatic and/or tectonic processes influenced the sedimentation of the upper Permian–Lower Triassic fluvial-lacustrine cyclic deposits in Bogda Mountains, greater Turpan-Junggar intracontinental rift basin, Xinjiang Uygur Autonomous Region, NW China. This study carried out gamma analysis, gamma and astronomical tuning, and spectral analysis on the Wutonggou, Jiucaiyuan, and Shaofanggou low-order cycles of the South and Central Taodonggou, South and North Tarlong, Dalongkou, and Zhaobishan sections. Stable and positive gamma values support the assumption of facies-dependent sedimentation rates for non-marine facies. The sedimentation rates range from 0.04 to 2.43 m/kyr, and 0.21 …

Integrating Stakeholder Priorities Into Resilience Planning And Investment Decision-Making, Victoria Jeaneen Kraemer

Doctoral Dissertations

"Resilience is a system’s ability to bounce back from a disruption. However, resilience needs may vary across different stakeholders. To better integrate stakeholder input into resilience planning and investment decision-making, existing frameworks were combined to develop the Integrated Stakeholder-Centered Resilience Framework. This broad framework is tailorable across contexts and stakeholder types. Research results demonstrate the use of this framework to evaluate the effects of disruptions and represent stakeholder preferences for investments. In the first study, participants were randomly assigned to power outage scenarios, which did not affect their criteria priorities. An exploratory factor analysis revealed two main priorities, (1) Absorption …

An Energy-Stable Mixed Cg-Dg Scheme For A Full Shliomis Phase Field Model Of Two-Phase Ferrofluid Flows, Mahdi Gharehbaygloo

Doctoral Dissertations

"Ferrofluids are magnetic nanoparticle suspensions whose motion couples surface tension, flow field, magnetostatics, and magnetization dynamics. This dissertation develops, analyzes, and validates an energy-stable finite element method for a two-phase ferrofluid model that couples the Cahn-Hilliard equations with the full Shliomis model of single-phase ferrofluids, retaining its damping torque term, magnetic torque term, and magnetic stress term.

The spatial discretization is a mixed continuous Galerkin (CG) and discontinuous Galerkin (DG) formulation. It uses continuous ��2 elements for the phase field, chemical potential, velocity, and magnetostatic potential, discontinuous ��2 elements for the magnetization, and discontinuous ��1 elements for the pressure. The …

Innovative Methods In Intact Rock Deformation Detection, Ali Abdullah M Alzahrani

Doctoral Dissertations

"An accurate assessment of intact rock deformation is imperative in engineering activities carried out either in or above rock masses. However, instruments used for post-peak deformation are easily debonded and cannot record the whole process of post-peak deformation required in the failure modeling of rocks. This dissertation focuses on the investigation of the performance of two non-contact measuring systems (Laser Displacement Sensor (LDS) and Inductive Proximity Sensor (IPS)) compared to the contact type instrument (conventional Strain Gauge System (SGS)) in monitoring intact rock deformations. Subsequently, an IPS was installed in a high-pressure triaxial testing system before investigating its performance in …

Anxiously Ever After: The Fear Of Choosing The Wrong Person Among Individuals With Relationship Obsessive-Compulsive Disorder, Liv Fante

PCOM Psychology Dissertations

Obsessive-compulsive disorder (OCD) is a distressing condition in which individuals experience recurrent intrusive and unwanted thoughts (i.e., obsessions), engage in repetitive behaviors (i.e., compulsions), or both. A relatively underexplored presentation of OCD involves obsessions and compulsions centered on romantic relationships, referred to as relationship OCD (ROCD). Although OCD has been extensively studied, research specific to ROCD remains limited. Disordered eating behaviors, retroactive jealousy, social media use, social comparison, and relationship history may be associated with the development and maintenance of ROCD. The current study examined these variables as predictors of two forms of ROCD: relationship-centered and partner-focused symptoms. Gender differences …

Phase I Study Of Niraparib With Radiotherapy For Treatment Of Metastatic And Locally Advanced Invasive Carcinoma Of The Cervix (Nivix), Piyush Pathak, Eunji Jo, Susan Hilsenbeck, Matthew L Anderson, Alfredo Echeverria, Shelly Sharma, Jan Sunde, Tracilyn Hall, Anthony Costales, Claire Hoppenot, Michelle Ludwig

Faculty, Staff and Students Publications

Introduction: This Phase I study evaluated the safety and tolerability of concurrent niraparib, an oral poly(ADP-ribose) polymerase (PARP) 1/2 inhibitor, with definitive radiotherapy in women with locally advanced or platinum-sensitive metastatic cervical cancer. Dose escalation followed a Bayesian Optimal Interval (BOIN) design with a target dose-limiting toxicity (DLT) rate of 30%.

Methods: Women ≥18 years with FIGO stage IIIC2 (bulky nodes >1 cm) or stage IV cervical cancer demonstrating response to platinum-based induction chemotherapy were eligible. Niraparib 100 mg was administered daily concurrent with pelvic radiotherapy (45-57.5 Gy via IMRT with nodal boosts) and brachytherapy, continuing 28 days post-radiation. Per …

Phase 1 Trial Of Withania Somnifera Leaf Extract (Rh324) In Advanced Non-Small Cell Lung Cancer Including [18f]Fdg Pet/Ct As A Short-Term Metabolic Biomarker To Assess Efficacy: A Novel Model For Assessment Of Complimentary Therapies In Early Phase Human Clinical Trials, Jin Uk Heo, Santosh Rao, Herbert B Newton, Afshin Dowlati, Raymond F Muzic, Arash Kardan

Faculty, Staff and Students Publications

Background: Withania somnifera (WS), commonly known as ashwagandha, has been used in the traditional medical system of India. It has shown significant activity against numerous solid tumor varieties in pre-clinical in vitro and in vivo studies. This study focuses on RH324 (ReHeva Biosciences, Columbus, OH), a pharmaceutical-grade formulation derived from WS, which has received FDA allowance for clinical development as a botanical drug in the treatment of cancer.

Methods: A phase 1 open label dose ranging study of oral RH324 in advanced non-small cell lung cancer (NSCLC) was conducted. The primary endpoint of the study was assessment of short-term safety …

Chemoradiation After Chemotherapy For Metastatic Cervical Cancer Can Provide Chemo-Free Time, Spoorthi Kamepalli, Ashley Chavana, Michelle Ludwig, Madeline Flanagan, Shelly Sharma, Tracilyn Hall, Anthony Costales, Jan Sunde, Claire Hoppenot

Faculty, Staff and Students Publications

Introduction: Stage IVB cervical cancer is treated with a life-prolonging and palliative intent with systemic chemotherapy and immunotherapy. The purpose of this study was to evaluate the number of these patients who had an adequate response to chemotherapy to be eligible for consolidative radiosensitizing chemotherapy and radiation (chemoradiation) and subsequent outcomes.

Materials and methods: This is a retrospective review of metastatic cervical cancer patients treated with chemotherapy and evaluated for treatment with consolidative pelvic chemoradiation at a single safety-net hospital system from 2016 to 2024. Demographic data and clinical information were collected from electronic medical records. Stata was used for …

Immune-Mediated Diarrhea And Colitis With Normal Biochemical, Endoscopic And Histologic Findings: A Retrospective Study, Malek Shatila, Sharada Wali, Carolina Colli Cruz, Kei Takigawa, Andres Caleb Urias Rivera, Kian Abdul-Baki, Tanvi Gupta, Elliot Baerman, Linfeng Lu, Irene Jeong-Ah Lee, Raakhi Menon, Hamza Salim, Andrew Sullivan, Varun Vemulapalli, Cristina Natha, Ayesha Khan, Krishnavathana Varatharajalu, Stephane Champiat, Kerry L Reynolds, Lucy B Kennedy, Katy Tsai, Anusha Shirwaiker Thomas, Yinghong Wang

Faculty, Staff and Students Publications

Background: Immune-mediated diarrhea and colitis (IMDC) due to checkpoint inhibition infrequently presents with normal stool biomarkers and no endoscopic or histologic evidence of inflammation. Little is known about the treatment needs and outcomes of this subset of patients. We aimed to describe this entity and clarify the role of immunosuppressive treatments in its management.

Method: This was a single-center, retrospective study of patients treated with immune checkpoint inhibitors who developed clinical symptoms of IMDC, with no evidence of inflammation based on fecal calprotectin or endoscopic/histologic evaluation, between January 2010 and February 2024.

Results: Of 1151 patients with IMDC, 131 (11.4%) …

Interdisciplinary Swiss Consensus Recommendations For Follow-Up After Radical Cystectomy And Trimodal Treatment For Muscle-Invasive Bladder Cancer, Ernest Kaufmann, Stefanie Aeppli, Andres Affentranger, Nicolas Arnold, Winfried Arnold, Fabian Aschwanden, Panagiotis Balermpas, Jörg Beyer, Uwe Bieri, Joost Boormanns, Richard Cathomas, Berardino De Bari, Marco Dressler, Daniel S Engeler, Andreas Erdmann, Andrea Gallina, Silvia Gomez, Matthias Guckenberger, Thomas Herrmann, Thomas Hermanns, Ilaria Lucca, Hubert John, Thomas Matthias Kessler, Jan Klein, Mohamed Laouiti, David Lauffer, Seth Paul Lerner, Agostino Mattei, Michael Müntener, Daniel Nguyen, Philipp Niederberger, Alexandros Papachristofilou, Lukas Prause, Paul Martin Putora, Karsten Reinhardt, Emanuela Salati, Philippe Sèbe, Mohamed Shelan, Silvan Sigg, Räto Thomas Strebel, Arnoud Jan Templeton, Ursula Vogl, Marian Severin Wettstein, Stephen Wyler, Deborah Zihler, Thomas Zilli, Daniel Zwahlen, Beat Roth, Christian Daniel Fankhauser

Faculty, Staff and Students Publications

Introduction: Radical cystectomy or trimodal therapy are treatment options for non-metastatic bladder cancer. However, there is limited evidence guiding post-treatment follow-up regimens, resulting in variations in care.

Objective: A Swiss consensus meeting aimed to identify gaps in follow-up strategies and subsequently tailoring follow-up protocols after curative treatment for bladder cancer.

Methods: A consensus meeting including participants from urology, oncology, radiation oncology, neuro-urology, international advisors, and patient representatives was held. 19 pre-formulated questions addressing follow-up duration, frequency, and modalities after radical cystectomy or trimodal therapy for bladder cancer were discussed and voted by participants.

Results: 42 experts from 22 institutions participated …

Senolytic-Resistant Senescent Cells Have A Distinct Sasp Profile And Functional Impact: The Path To Developing Senosensitizers, Utkarsh Tripathi, Masayoshi Suda, Vagisha Kulshreshtha, Bryan T Piatkowski, Allyson K Palmer, Nino Giorgadze, Christina Inman, Nathan Gasek, Ming Xu, Kurt O Johnson, Tamar Pirtskhalava, Selim Chaib, Larissa P G Langhi Prata, Yi Zhu, Renuka Kandhaya-Pillai, Stefan G Tullius, Saranya P Wyles, Rambabu Majji, Hari Krishna Yalamanchili, David B Allison, Tamar Tchkonia, James L Kirkland

Faculty, Staff and Students Publications

The senescent cell (SC) fate is linked to aging, multiple disorders and diseases, and physical dysfunction. Senolytics, agents that selectively eliminate 30%-70% of SCs, act by transiently disabling the senescent cell antiapoptotic pathways (SCAPs), which defend those SCs that are proapoptotic and pro-inflammatory from their own senescence-associated secretory phenotype (SASP). Consistent with this, a JAK/STAT inhibitor, Ruxolitinib, which attenuates the pro-inflammatory SASP of senescent human preadipocytes, caused them to become "senolytic-resistant". Administering senolytics to obese mice selectively decreased the abundance of the subset of SCs that is pro-inflammatory. In cell cultures, the 30%-70% of human senescent preadipocytes or human umbilical …

Consumer Responses To Ethical And Privacy Concerns In Ai Chatbots: Evidence From Offensive Language, Gender Bias, And Digital Privacy, Jikhan Jeong

Economics Faculty Research & Creative Works

Due to the rapid innovation of artificial intelligence (AI) and big data, AI chatbots have become increasingly influential computational social systems (CSS) in everyday life. However, the expansion of interactions between AI chatbots and consumers has raised significant ethical and privacy concerns. Using data from an online survey, this study empirically examines how consumer concerns about AI ethics and privacy influence their intention to use AI chatbots. These concerns are categorized into three types: 1) offensive language (generated by AI chatbots or users); 2) gender-biased language (from either source); and 3) digital privacy violations. The findings suggest that prior experience …

Psychometric Properties Of A Novel Affective Bias Task And Its Application In Clinical And Nonclinical Populations, Prathik Kalva, Kourtney Kanja, Brian A Metzger, Xiaoxu Fan, Brian Cui, Bailey Pascuzzi, John Magnotti, Madaline Mocchi, Raissa Mathura, Kelly R Bijanki

Faculty, Staff and Students Publications

To mitigate limitations in self-reported mood assessments, we introduce a novel affective bias task (ABT). The task quantifies instantaneous emotional state by leveraging the phenomenon of affective bias, in which people interpret external emotional stimuli in a manner consistent with their current emotional state. This study establishes task stability in measuring and tracking depressive symptoms in clinical and non-clinical populations. Initial assessment in a large non-clinical sample established normative ratings. Depressive symptoms were tracked relative to task performance in a non-clinical sample, as well as in a clinical cohort undergoing surgical evaluation for severe epilepsy. In both cohorts, a stronger …

Dental Professionalism In A Changing World: Challenges & Opportunities, Robert P. Iovino, Dds, Ma Dds, Ma

Journal of the American College of Dentists

This manuscript examines the erosion of traditional dental professionalism amid rising educational costs, declining membership in professional associations, and the growing influence of corporate ownership and private equity in dentistry. Drawing perspectives from economics, sociology, philosophy, law, and ethics, it traces the historical development of professional licensure and its role in safeguarding clinical autonomy, ethical integrity, and public trust. The analysis highlights how deregulation and profit-driven practice models challenge the profession’s social contract. The manuscript argues that preserving strong civic institutions, restrictive licensure standards, and humanities-informed education is essential to sustaining dentistry as a learned profession rather than a commodified …

Hester’S Dubious Roots And Legacy: Open Fields Doctrine Under Scrutiny, Laura K. Donohue

Georgetown Law Faculty Publications and Other Works

For over a century, open fields doctrine has shaped Fourth Amendment law, denying people the right to be secure on their own property. Its application has steadily expanded, with the result that, by some estimates, the Government can now engage in warrantless surveillance of some ninety-six percent of private land and buildings regardless of fences, postings, the distance from public roads or byways, or the use to which the property is put. An originalist approach throws the doctrine into disarray: at the time of the Founding, common law protected the curtilage, which extended to the fields, barns, storehouses, and other …

Religious Freedom, Jesuit Mission, And Dei, William M. Treanor, Amelia J. Uelmen

Georgetown Law Faculty Publications and Other Works

The ability of Jesuit educational institutions to pursue a central part of their mission – that of fostering diverse, equitable and inclusive educational environments – is under attack. This essay outlines several dimensions of their religiously-grounded mission and the reasons to strongly protect from government interference the rights of Jesuit universities to implement programs and practices that align with DEI values. First, for Jesuit universities, these programs and practices are rooted in a much deeper culture of the more than 2,000-year old Catholic intellectual tradition and the now 500-year old tradition of Jesuit spirituality. Second, drawing on the classic work …

Creation And The Republican Revival, William M. Treanor

Georgetown Law Faculty Publications and Other Works

Gordon Wood's classic book Creation of the American Republic has long influenced legal thought and originalist scholarship in particular. It played a central role in the Republican Revival movement, an effort by leading scholars such as Cass Sunstein and Frank Michelman to recover a progressive originalism at the same time as conservative originalism was starting to shape constitutional jurisprudence. But, while the Republican Revival nominally relied on Wood, it misread central elements of his book - his concept of virtue and his belief that republicanism had largely been displaced at the time of the drafting of the Constitution.

The time …

Reconstituting A Constitution, And A Republic: The Architecture Of Authoritarian Rule, J. Maria Glover

Georgetown Law Faculty Publications and Other Works

A constitution can be remade without tearing it down, or even changing a single word. It is done by law.

“The judicial power is vested in one Supreme Court and in such inferior courts as Congress may establish,” whose “province and duty” it is to “say what the law is.” U.S. Const. Art. III §1; Marbury v. Madison, 5 U.S. 1 (Cranch) 137 (1803). It is not the power to remake the Constitution that grants it.

The Supreme Court is turning the inherited powers that hold power to law into instruments of its own aggrandizement. It is taking authority from …

From Measuring Clicks To Inclusion: Coverage Of Digital Adolescent Sexual And Reproductive Health Programs, Miriam Temin, Christabel Gero

Adolescents and Young People

Digital platforms have become popular tools to address adolescents’ sexual and reproductive health and rights (ASRHR) in low- and middle-income countries. Digital programming has the potential to bridge the SRHR information gap, especially for adolescents who face SRHR risks. Given what is known about the digital divide, it is essential to understand who digital ASRHR programming reaches, who is excluded, and how coverage aligns with risk. This brief summarizes an exploration that aims to stimulate interest and seed research on issues of coverage of digital programming for adolescents and its public health importance.

It’S All One Curriculum: Guidelines And Activities For A Unified Approach To Sexuality, Gender, Hiv, And Human Rights Education 2nd Edition, Heidy Araque, Nicole Haberland

Adolescents and Young People

The second edition is forthcoming

Rise, Lead, Thrive: A Young Feminist's Path To Leadership, Population Council Kenya, Nawiri Project

Adolescents and Young People

Information Education and Communication graphic created for the Young Feminist Organizing (YFO) project.

Multi-Period Coordinated Planning Of Xfcs In Coupled Tn-Pdn Networks: Integrating Demand Charge Reduction And Pre-Existing Infrastructure, Waqas Ur Rehman, Siyuan Wang, Liheng Lv, Jonathan W. Kimball, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

The widespread adoption of electric vehicles (EVs) and transportation electrification is encumbered by two chief barriers: i) the limited driving range of EVs in the market today and ii) inadequate charging infrastructure support. This paper aims to address the latter bottleneck and proposes a strategic multi-period coordinated planning model to optimally site and size battery energy storage system (BESS) assisted extreme fast charging stations in a highway transportation network and solar systems in a power distribution network. The proposed approach accounts for pre-existing charging stations, the increasing EV penetration levels, decreasing technology costs, and technological advancements in the future and …

Temperature Compensation In Loop And Patch Fss Strain Sensors: Analysis And Experimental Validation, Swathi Muthyala Ramesh, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Frequency selective surfaces (FSSs) are arrays of conductive elements or apertures that exhibit frequency-dependent reflection and transmission properties. Their electromagnetic response is influenced by geometry and environmental conditions, making them attractive for wireless strain-sensing applications. However, temperature variations can produce frequency shifts similar to those caused by strain, reducing measurement accuracy. This work investigates the effects of intrinsic temperature compensation on two common FSS unit cell geometries—loop and patch—through comprehensive simulation analysis. The results show that loop-based cells offer superior thermal stability, while patch-based cells provide greater strain sensitivity, illustrating the trade-off between thermal robustness and mechanical responsiveness. A patch-type …

Mitigating Hysteresis In Metal-Coated Fibers Via Optimized Thermal Treatment For Advanced Distributed High-Temperature Sensing Applications, Koustav Dey, Rony Kumer Saha, Bohong Zhang, S. Narasimman, Farhan Mumtaz, Jeffrey D. Smith, Rex E. Gerald, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Metal-coated optical fibers are widely employed in sensing applications owing to their superior mechanical strength and corrosion resistance. However, their calibration at elevated temperatures is hindered by hysteresis, manifested as discrepancies between heating and cooling cycles, primarily caused by residual strain from mismatched thermal expansion coefficients (TECs) between the metal coating and silica cladding. This research introduces an optimal heat treatment procedure aimed at minimizing the impact of the mismatch in TECs between the cladding and the coating materials that causes the residual strain in gold (Au) and copper (Cu) coated fibers for achieving reliable distributed high temperature sensing up …

Large Language Models For Neurology: A Mini Review, Donald C. Wunsch, Daniel B. Hier

Electrical and Computer Engineering Faculty Research & Creative Works

Large language models have the potential to transform neurology by augmenting diagnostic reasoning, streamlining documentation, and improving workflow efficiency. This Mini Review surveys emerging applications of large language models in Alzheimer's disease, Parkinson's disease, multiple sclerosis, and epilepsy, with emphasis on ambient documentation, multimodal data integration, and clinical decision support. Key barriers to adoption include bias, privacy, reliability, and regulatory alignment. Looking ahead, neurology-focused language models may develop greater fluency in biomedical ontologies and FHIR standards, improving data interoperability and supporting more seamless collaboration between clinicians and AI systems. Two future developments have the potential to be particularly impactful: (1) …

Evaluation Of Multiple Generative Large Language Models On Neurology Board-Style Questions, Mohammad Almomani, Vijaya Valaparla, James Weatherhead, Xiang Fang, Alok Dabi, Chih Ying Li, Peter Mccaffrey, Dan Hier, Jorge Mario Rodríguez-Fernández

Electrical and Computer Engineering Faculty Research & Creative Works

Objective: To compare the performance of eight large language models (LLMs) with neurology residents on board-style multiple-choice questions across seven subspecialties and two cognitive levels. Methods: In a cross-sectional benchmarking study, we evaluated Bard, Claude, Gemini v1, Gemini 2.5, ChatGPT-3.5, ChatGPT-4, ChatGPT-4o, and ChatGPT-5 using 107 text-only items spanning movement disorders, vascular neurology, neuroanatomy, neuroimmunology, epilepsy, neuromuscular disease, and neuro-infectious disease. Items were labeled as lower- or higher-order per Bloom's taxonomy by two neurologists. Models answered each item in a fresh session and reported confidence and Bloom classification. Residents completed the same set under exam-like conditions. Outcomes included overall and …

Safety Aware Continual Reinforcement Learning-Based Output Tracking Control Of Nonlinear Continuous-Time Systems, Irfan Ganie, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

An output feedback (OF)-based control scheme utilizing both a scalable multilayer neural network (MNN) observer and actor–critic MNN via integral reinforcement learning (IRL)/adaptive dynamics programming (ADP) approach for a class of nonlinear systems with output constraints is introduced. The proposed observer, critic, and actor MNN weight updates are derived using a singular value decomposition (SVD) of MNN activation function gradient along with output error, Bellman and control input errors, respectively. Next, the approach incorporates continual learning (CL), utilizing a penalty function in the weight update laws for both actor–critic MNNs to consolidate knowledge from previous tasks and enhance learning in …