Digital Commons Network^™

Algebraic Speed Estimation For Sensorless Induction Motor Control: Insights From An Electric Vehicle Drive Cycle, Jorge Neira-Garcia, Andres Beltran-Pulido, John Cortes-Romero

Purdue University Libraries Open Access Publishing Fund

Induction motors (IMs) must meet high reliability and safety standards in mission-critical applications, such as electric vehicles (EVs), where sensorless control strategies are fundamental. However, sensorless rotor speed estimation demands improvements to overcome filtering distortions, tuning complexities, and sensitivity to IM model mismatch. Algebraic methods offer inherent filtering capabilities and design flexibility to address these challenges without introducing additional dynamics into the control system. The objective of this paper is to provide an algebraic estimation strategy that yields an accurate rotor speed estimate for sensorless IM control. The strategy includes an algebraic estimator with single-parameter tuning and inherent filtering action. …

Photodynamic Treatment Of Staphylococcus Aureus With Non-Iron Hemin Analogs In The Presence Of Hydrogen Peroxide, Badhu Prashanthika Sivasubramaniam, Benjamin M. Washer, Yuichiro Watanabe, Kathryn E. Ragheb, J. Paul Robinson, Alexander Wei

Department of Chemistry Faculty Publications

Bacteria subjected to antiseptic or antibiotic stress often develop tolerance, a trait that can lead to permanent resistance. To determine whether photodynamic agents could be used to counter tolerance, we evaluated three non-iron hemin analogs (M-PpIX; M = Al, Ga, In) as targeted photosensitizers for antimicrobial photodynamic inactivation (aPDI) following exposure to sublethal H2O2. Al-PpIX is an active producer of ROS whereas Ga- and In-PpIX are more efficient at generating singlet oxygen. Al- and Ga-PpIX are highly potent aPDI agents against S. aureus and methicillin-resistant strains (MRSA) with antimicrobial activity (3 log reduction in colony-forming units) at nanomolar concentrations. The …

Türkiye's Sustainable Tourism Transformation: An Overview, Mustafa Sogut

GSTC Academic Symposium - In conjunction with the GSTC Global Conference

Türkiye has initiated a paradigm shift in its tourism industry, marked by a collaboration with the Global Sustainable Tourism Council (GSTC), renowned for setting robust sustainability standards. The agreement, initiated in 2022, prioritizes sustainability commitment, commencing with formulating national program criteria and certification bodies training. The initial phase is targeted for completion by the end of 2023, with subsequent stages progressively implemented by 2025, ultimately aiming to meet all international standards by 2030.

This strategic move aims to position Turkey prominently in sustainable tourism, aligning with the goals of The Paris Agreement. Turkey has proactively steered its tourism industry towards …

Factors Supporting Academic Engagement Among Cambodian American High School Youth, Vichet Chhuon, Angela Dosalmas, Nida Rinthapol

Journal of Southeast Asian American Education and Advancement

This exploratory study examined the relationship between Cambodian American

students’ (N = 77) attitudes and beliefs regarding school climate and school

engagement. We examined engagement through two primary constructs:

academic intrinsic motivation and future educational expectations. Four specific

correlates of engagement were examined to understand the quality of Cambodian

American students’ school engagement: sense of racial fairness; feelings of

teacher support; perceptions of self-competence; and perceptions of positive

classroom environment. Perceptions of self competence were positively

associated with higher educational expectations. Our regression models found

that students’ sense of positive classroom environment in addition to teacher

support was important …

Self-Consistent Atmosphere Representation And Interaction In Photon Monte Carlo Simulations, J. R. Peterson, G. Sembroski, A. Dutta, C. Remocaldo

Purdue University Libraries Open Access Publishing Fund

We present a self-consistent representation of the atmosphere and implement the interactions of light with the atmosphere using a photon Monte Carlo approach. We compile global climate distributions based on historical data, self-consistent vertical profiles of thermodynamic quantities, spatial models of cloud variation and cover, and global distributions of four kinds of aerosols. We then implement refraction, Rayleigh scattering, molecular interactions, and Tyndall–Mie scattering to all photons emitted from astronomical sources and various background components using physics first principles. This results in emergent image properties that include: differential astrometry and elliptical point spread functions (PSFs) predicted completely to the horizon, …

Fallen Ears From Introductory Statistics, Yoon G. Kim

KAUPA Letters

No abstract provided.

The Escape Of Fast Radio Burst Emission From Magnetars, Maxim Lyutikov

Purdue University Libraries Open Access Publishing Fund

We reconsider the escape of high-brightness coherent emission of fast radio bursts (FRBs) from magnetars’ magnetospheres, and conclude that there are numerous ways for the powerful FRB pulse to avoid non-linear absorption. Sufficiently strong surface magnetic fields, more than or equal to 10 percent of the quantum field, limit the waves’ non-linearity to moderate values. For weaker fields, the electric field experienced by a particle is limited by a combined ponderomotive and parallel-adiabatic forward acceleration of charges by the incoming FRB pulse along the magnetic field lines newly opened during FRB/coronal mass ejection. As a result, particles surf the weaker …

Geospatial Analysis Of Agricultural Potential In The United States, Diana Febrita

Graduate Industrial Research Symposium

Traditionally, the agriculture sector is responsible for providing food and crop products. However, the role of agriculture has expanded beyond its traditional function. It is the main sector that contributes to the provision of food, income, employment, environmental protection, and local economic development. Reflecting on the roles of agriculture, understanding the potential of agriculture in the United States is crucial to discovering the prospects and challenges. This study will briefly discuss the agricultural potential in the United States based on the five assets, including natural capital, financial capital, human capital, physical capital, and social capital. To identify the states with …

Accuracy Of Nitrate Hysteresis And Flushing For Agricultural Watersheds In The Midwest, Noah Rudko, Sara K. W. Mcmillian, Jane Frankenberger, François Birgand

Graduate Industrial Research Symposium

Storm event-based metrics, such as hysteresis (HI) and flushing (FI), are used to differentiate nitrate pathways and sources, which is essential for watershed management. Estimations of these event-based metrics typically use high frequency (15-minute – hourly) measurements, but daily data are also used due to their greater availability. To date, there has been no study assessing how using lower frequency samples affect the accuracy of HI and FI, which could skew interpretation of potential nutrient pathways and sources. We used continuous measurements of nitrate collected at 9 watersheds throughout the Midwest spanning 448 storms. HI and FI were estimated from …

Comparative Life Cycle Assessment Of Copper Production, Xiaohan Wu

Graduate Industrial Research Symposium

Copper demand will surge significantly in the context of global renewable energy technology implementation, but its production is an energy-intensive process. It is crucial to choose the best production method to reduce environmental damage in terms of the enormous copper supply. This research develops a multi-criteria life cycle assessment model for the three main copper production routes- pyrometallurgy, hydrometallurgy, and bioleaching. We complied material and energy flow data to assess each route's life cycle greenhouse gas (GHG) emissions, cost, and resource efficiency. Results indicate bioleaching emits the least GHG emissions (4.09 kg-CO2 eq/kg copper) among the three routes. Hydrometallurgy is …

Characterization Of Biological Particles Using An Integrated Hyperspectral Imaging And Machine Learning, Kaeul Lim, Arezoo Ardekani

Graduate Industrial Research Symposium

Hyperspectral imaging (HSI) is a promising modality in medicine with many potential applications. This study focuses on developing a label-free lipid nanoparticle characterization method using a convolutional neural network (CNN) analysis of HSI images. The HSI data, hypercube, consists of a series of images acquired at different wavelengths for the same field of view, providing continuous spectra information for each pixel. Three distinct liposome samples were collected for analysis. Advanced image preprocessing and classification methods for HSI data were developed to differentiate liposomes based on their material compositions. Our machine learning-based classification method was able to distinguish different liposome types …

Sepsis Treatment: Reinforced Sequential Decision-Making For Saving Lives, Dipesh Tamboli, Jiayu Chen, Kiran Pranesh Jotheeswaran, Denny Yu, Vaneet Aggarwal

Graduate Industrial Research Symposium

Sepsis, a life-threatening condition triggered by the body's exaggerated response to infection, demands urgent intervention to prevent severe complications. Existing machine learning methods for managing sepsis struggle in offline scenarios, exhibiting suboptimal performance with survival rates below 50%. Our project introduces the "PosNegDM: Reinforcement Learning with Positive and Negative Demonstrations for Sequential Decision-Making" framework utilizing an innovative transformer-based model and a feedback reinforcer to replicate expert actions while considering individual patient characteristics. A mortality classifier with 96.7% accuracy guides treatment decisions towards positive outcomes. The PosNegDM framework significantly improves patient survival, saving 97.39% of patients and outperforming established machine learning …

Online Class-Incremental Learning For Real-World Food Image Classification, Siddeshwar Raghavan, Jiangpeng He, Fengqing Zhu

Graduate Industrial Research Symposium

Food image classification is essential for monitoring health and tracking dietary in image-based dietary assessment methods. However, conventional systems often rely on static datasets with fixed classes and uniform distribution. In contrast, real-world food consumption patterns, shaped by cultural, economic, and personal influences, involve dynamic and evolving data. Thus, it requires the classification system to cope with continuously evolving data. Online Class Incremental Learning (OCIL) addresses the challenge of learning continuously from a single-pass data stream while adapting to the new knowledge and reducing catastrophic forgetting. Experience Replay (ER) based OCIL methods store a small portion of previous data and …

Modelling The "Bottom-Up" Development Pattern Of Tar Spot Disease In Corn, Brenden Lane, Joaquín Guillermo Ramírez-Gil, Carlos Góngora-Canul, Mariela Sofia Fernandez Campos, Andres Cruz-Sancan, Fidel E. Jiménez-Beitia, Alex G. Acosta-Guatemal, Wily Sic, C. D. Cruz

Graduate Industrial Research Symposium

In 2015, the corn-infecting pathogen Phyllachora maydis (causal agent of tar spot disease) was reported for the first time in the United States. The disease has since spread across the US, causing major yield losses. In 2021 alone, 5.88 million metric tons (231.3 million bushels) of US corn yield were lost to this disease, costing an estimated US$1.25 billion. Though fungicides can protect against these agroeconomic losses, application timing can be difficult to optimize because our understanding of tar spot dynamics is still evolving. The current view is that tar spot typically develops bottom-up through a repeating infection cycle. Because …

A Machine Learning Model Of Perturb-Seq Data For Use In Space Flight Gene Expression Profile Analysis, Liam F. Johnson, James Casaletto, Lauren Sanders, Sylvain Costes

Graduate Industrial Research Symposium

The genetic perturbations caused by spaceflight on biological systems tend to have a system-wide effect which is often difficult to deconvolute it into individual signals with specific points of origin. Single cell multi-omic data can provide a profile of the perturbational effects, but does not necessarily indicate the initial point of interference within the network. The objective of this project is to take advantage of large scale and genome-wide perturbational datasets by using them to train a tuned machine learning model that is capable of predicting the effects of unseen perturbations in new data. Perturb-Seq datasets are large libraries of …

Ai Tools For Literature Reviews, Jing Lu, Zoeanna A. Mayhook

Libraries Faculty and Staff Presentations

With the proliferation of AI tools, graduate students often ask themselves how these tools can be ethically used to bolster their research. ChatGPT has gained traction, but its utility is constrained by issues like outdated information, artificial hallucinations, and limited access to scholarly publications hidden behind a paywall. Fortunately, new AI tools have been developed that promote academic exploration and discovery, such as offering generative article summaries, citation chaining, and thematic literature mapping capabilities. This workshop will explore three AI tools—Perplexity, Research Rabbit, and Inciteful—designed to support the research and literature review process. This session will provide a demonstration showcasing …

Impact Analysis Of Roadway Surface And Vehicle Conditions On Fleet Formation For Connected And Automated Vehicles, Ping Yi, Tariq Alqubaysi

Center for Connected and Automated Transportation

Taking advantage of the rapid development of vehicle control and communication technologies, many studies have suggested that operating vehicles in platoons in the future would help improve the safety and efficiency of the transportation system. Although vehicles in a platoon can share data from V2/V communication, a platoon model built on proper control laws is needed to keep the formation of the vehicle fleet and take the real advantage in platoon operations in an environment encompassing different pavement, roadway, and tire conditions. This research introduces a platoon model using a headway-based distance control policy to maintain stability and reduce errors …

Towards A Posthumanist Sociomaterial Conceptualization Of Intercultural Rhetoric, Amir Kalan

Journal of Rhetoric, Professional Communication, and Globalization

Intercultural rhetoric has a human-centered view of culture and considers humans’ ethnicities, beliefs, and social practices as crucial components of rhetorical traditions. Conceptualizing a posthumanist sociomaterial approach to intercultural rhetoric, this article suggests that writing across cultures can be viewed as rhetorical transition between two sociomaterial networks with non-human, as well as human, factors. It explains that posthuman intercultural rhetoric can turn into a field where researchers study political, economic, and administrative networks in which texts are funded, constructed, regulated, disseminated, sold, bought, and cited. This area of writing studies would be interested in how rhetoric is constructed and used …

Granular Estimation Of User Cognitive Workload Using Multi-Modal Physiological Sensors, Jingkun Wang, Christopher Stevens, Winston Bennett, Denny Yu

Purdue University Libraries Open Access Publishing Fund

Mental workload (MWL) is a crucial area of study due to its significant influence on task performance and potential for significant operator error. However, measuring MWL presents challenges, as it is a multi-dimensional construct. Previous research on MWL models has focused on differentiating between two to three levels. Nonetheless, tasks can vary widely in their complexity, and little is known about how subtle variations in task difficulty influence workload indicators. To address this, we conducted an experiment inducing MWL in up to 5 levels, hypothesizing that our multi-modal metrics would be able to distinguish between each MWL stage. We measured …

Evaluation Of Fendiline Treatment In Vp40 System With Nucleation-Elongation Process: A Computational Model Of Ebola Virus Matrix Protein Assembly, Xiao Liu, Monica Husby, Robert V. Stahelin, Elsje Pienaar

Purdue University Libraries Open Access Publishing Fund

Ebola virus (EBOV) infection is threatening human health, especially in Central and West Africa. Limited clinical trials and the requirement of biosafety level-4 laboratories hinder experimental work to advance our understanding of EBOV and the evaluation of treatment. In this work, we use a computational model to study the assembly and budding process of EBOV and evaluate the effect of fendiline on these processes in the context of fluctuating host membrane lipid levels. Our results demonstrate for the first time that the assembly of VP40 filaments may follow the nucleation-elongation theory, as this mechanism is critical to maintaining a pool …

Log-Linear Dynamic Inversion Control With Provable Safety Guarantees In Lie Groups, Li-Yu Lin, James Goppert, Inseok Hwang

School of Aeronautics and Astronautics Faculty Publications

In this article, we use the derivative of the exponential map to derive the exact evolution of the logarithm of the tracking error for mixed-invariant systems, a class of systems capable of describing rigid body tracking problems in Lie groups. In addition, we design a log-linear dynamic inversion-based control law to remove the nonlinearities due to spatial curvature and enhance the robustness of the controller. We apply linear matrix inequalities to bound the tracking error given a bounded disturbance amplified by the distortion matrix and leverage the tracking error bound to create flow pipes. To demonstrate the usefulness of our …

Teaching And Learning In Stem With Computation, Modeling, And Simulation Practices, Alejandra J. Magana

Purdue University Press Books

Computation, modeling, and simulation practices are commonplace in the STEM workplace, yet formal training embedded in disciplinary practices is not as standard in the undergraduate classroom. Teaching and Learning in STEM With Computation, Modeling, and Simulation Practices: A Guide for Practitioners and Researchers gives instructors a handbook to ensure their curriculum bridges the gap between the classroom and workplace by equipping students with computational skills and preparing them for a rewarding career in STEM. Grounded in theory and supported by fifteen years of education research at the undergraduate level, this book provides instructional, pedagogical, and assessment guidance for integrating modeling …

A Fractal Art Approach To The Three-Body Problem, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

This preliminary study explores a new search strategy for identifying relatively stable vs. unstable solutions to the planar three-body problem in astrophysics, starting from the perspective of computer-generated art. Here classical Newtonian accelerations, speeds, and positions of all three bodies in a fixed plane are calculated. All three bodies are stationary at time zero, and the fate of the system is classified as reflecting either a bound stable orbit, a likely collision, or the ejection of one body. The initial position of one of the three bodies is varied in the image plane, and the outcome coded as one of …

Sampling-Accelerated Prediction Of Phonon Scattering Rates For Converged Thermal Conductivity And Radiative Properties, Ziqi Guo, Zherui Han, Dudong Feng, Guang Lin, Xiulin Ruan

Purdue University Libraries Open Access Publishing Fund

The prediction of thermal conductivity and radiative properties is crucial. However, computing phonon scattering, especially for four-phonon scattering, could be prohibitively expensive, and the thermal conductivity for silicon after considering four-phonon scattering is significantly under-predicted and not converged in the literature. Here we propose a method to estimate scattering rates from a small sample of scattering processes using maximum likelihood estimation. The calculation of scattering rates and associated thermal conductivity and radiative properties are dramatically accelerated by three to four orders of magnitude. This allows us to use an unprecedented q-mesh (discretized grid in the reciprocal space) of 32 × …

Who Counts As Diverse? The Strategic Broadening And Narrowing Of Diversity, Junming Zhang, Teri A. Kirby

Purdue University Libraries Open Access Publishing Fund

Introduction: A large majority of US organizations profess a commitment to diversity, but their definitions of diversity can vary greatly. While previous research demonstrates a shift in diversity definitions to include fewer protected demographic groups and more non-demographic characteristics, the present research examines whether this shift might be a motivated process among dominant group members related to anti-egalitarian and colorblind belief systems.

Methods: Using quantitative and qualitative methods, we explored potential underlying ideologies that may be associated with White Americans’ shifting definitions of diversity. White Americans (N = 498) were asked how they define diversity, as well as who …

Expanding Landscapes: Intersections Between Writing Center Work And Other Academic Fields, Vicki R. Kennell, Maria Eloisa (Lisa) Nuguid, Vanessa Pruitt, Ashley Garla

Purdue Writing Lab/Purdue OWL Presentations

This presentation explores the intersections between writing center work and math education, counseling psychology, and speech/hearing sciences. The four fields share more similarities than first expected, such as prioritizing relational approaches and maintaining client agency. Implications for writing centers include the need to adjust consultant education to overtly explore such overlaps in order to increase new consultants’ confidence and circumvent potential problems caused by differing assumptions.

Sample Lab Notes For “Applied Multivariate Statistics” For Upper-Level Undergraduate Students Or Beginning-Level Grad Students, Yoon G. Kim

KAUPA Letters

No abstract provided.

Eocene (50–55 Ma) Greenhouse Climate Recorded In Nonmarine Rocks Of San Diego, Ca, Usa, Adrian P. Broz, Devin Pritchard-Peterson, Diogo Spinola, Sarah Schneider, Gregory Retallack, Lucas C.R. Silva

Purdue University Libraries Open Access Publishing Fund

Nonmarine rocks in sea cliffs of southern California store a detailed record of weathering under tropical conditions millions of years ago, where today the climate is much drier and cooler. This work examines early Eocene (~ 50–55 million-year-old) deeply weathered paleosols (ancient, buried soils) exposed in marine terraces of northern San Diego County, California, and uses their geochemistry and mineralogy to reconstruct climate and weathering intensity during early Eocene greenhouse climates. These Eocene warm spikes have been modeled as prequels for ongoing anthropogenic global warming driven by a spike in atmospheric CO2. Paleocene-Eocene thermal maximum (PETM, ~ 55 Ma) kaolinitic …

Alumni Spotlight: Emma Wallens

The Journal of Purdue Undergraduate Research

Emma Wallens published an article in volume 8 (2018) of the Journal of Purdue Undergraduate Research during her time spent completing her baccalaureate degree.

Alumni Spotlight: Chufan Gao

The Journal of Purdue Undergraduate Research

Chufan Gao published an article in volume 8 (2018) of the Journal of Purdue Undergraduate Research during his time spent completing his baccalaureate degree.