VTechWorks
VTechWorks provides global access to Virginia Tech scholarship, including journal articles, books, theses, dissertations, conference papers, slide presentations, technical reports, working papers, administrative documents, videos, images, and more by faculty, students, and staff. Faculty can deposit items to VTechWorks from Elements, including journal articles covered by the University open access policy. Email vtechworks@vt.edu for help.
Open Access Policy
Virginia Tech's open access policy enables researchers to deposit the accepted version of scholarly articles with no embargo.
Theses and Dissertations
Virginia Tech was first in the world to require ETDs in 1997, and continues to add scans of older theses and dissertations.
Open Textbooks
More than 40 freely available and openly licensed textbooks are among our most downloaded items.
Communities in VTechWorks
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Recent Submissions
CREATING FACULTY GUIDELINES FOR COLLABORATIVE ONLINE INTERNATIONAL LEARNING: DESIGN AND DEVELOPMENT
Mukuni, Candido (Virginia Tech, 2024-12-20)
Development of an Automated Coin Grading System: Integrating Image Preprocessing, Feature Extraction, and ML Modeling
Chen, Jianzhu (Virginia Tech, 2024-12-20)
For more than 70 years, the Sheldon Coin Grading Scale has been essential in quantifying the value of coins within the coin collecting industry. Traditionally, coin grading has relied on human graders who may deliver inconsistent results. This inconsistency leads to variations in coin values. In this thesis, we present an automated coin grading system that uses image preprocessing, feature extraction, and advanced machine learning techniques to predict the grade across different coin types. Our system employs synthetic reference masks to identify "expected" regions, like the contours of reliefs, and "unexpected" regions, such as surface non-uniformities. All detected significant elements and tiny elements, extracted from these regions, will serve as one of the feature sets. Additionally, we extract color histograms as another feature set to analyze color and texture in detail. Both feature sets from the obverse and reverse sides of the coins are processed using a multi-layer perceptron (MLP) model and a random forest model. The best-performing model is then selected to grade the coins by analyzing their overall wear patterns and color characteristics. Our grading system has demonstrated an accuracy of up to 91.3% in predicting the Sheldon Grading Scale across five coin types, allowing for a grading tolerance of ±4. For a single coin type (Franklin Half Dollar), it has achieved an accuracy of up to 95.1% with a tolerance of ±1.
An XR-Driven Digital Twin Platform for Cybersecurity Education
Lee, Anthony Sung Ning (Virginia Tech, 2024-12-20)
This thesis investigates the application of digital twins as an educational tool within the domain of cybersecurity, specifically targeting the infrastructure of water treatment plants.
A digital twin is a precise virtual model of a physical asset, process, or system, capturing its state, behavior, and interactions in real-time.
By integrating live sensor data, historical records, and predictive models, digital twins replicate their physical counterparts with high fidelity, enabling detailed simulations, monitoring, diagnostics, and analytics.
This technology supports improved decision-making, predictive maintenance, and operational efficiency across industries by allowing safe testing and evaluation of modifications without altering physical assets.
A case study is presented to demonstrate an immersive experiential learning platform that leverages digital twins to provide cybersecurity education.
The platform aims to enhance user engagement and reinforce learning by offering hands-on experiences in a controlled virtual environment.
In addition, we provide a cost-efficient hardware solution that represents the physical side of the digital twin as connecting it to the actual water treatment plant hardware is unfeasible.
The study compares AI-guided learning, facilitated by a Conversational AI agent utilizing Large Language Models, against a non-AI-guided approach.
This comparison evaluates the effectiveness of AI in guiding users naturally through the learning process, thereby examining the potential of digital twins to support efficient, cost-effective education across diverse sectors.
The results show that presence is significantly increased with the help of an AI character while other qualities and factors remain unaffected.
However, we see learning improvement overall and received positive feedback regarding the system.
Users liked the digital twin concept and felt like it really helped them understand the concept thoroughly.
FaaSr: Cross-Platform Function-as-a-Service Serverless Scientific Workflows in R
Park, Sungjae; Thomas, R. Quinn; Carey, Cayelan C.; Delany, Austin D.; Ku, Yun-Jung; Lofton, Mary E.; Figueiredo, Renato J. (IEEE, 2024-09)
Modern Function-as-a-Service (FaaS) cloud platforms offer great potential for supporting event-driven scientific workflows. Nonetheless, there remain barriers to adoption by the scientific community in domains such as environmental sciences, where R is the focal language used for the development of applications and where users are typically not well-versed with FaaS APIs. This paper describes the design and implementation of FaaSr, a novel middleware system that supports event-driven scientific workflows in R. A key novelty in FaaSr is the ability to deploy workflows across FaaS providers without the need for any managed servers for coordination. With FaaSr: 1) functions are written in R; 2) the runtime environments for their execution are customizable containers; 3) functions access data in cloud storage (S3) with a familiar file-based abstraction supporting both full file put/get primitives and subsetting using the Parquet format; and 4) function invocation and workflow coordination only requires S3 cloud object storage, without relying on any dedicated, active workflow engine server or cloud-specific queues/databases. The paper reports on the functionality and performance of FaaSr for micro-benchmarks and two case studies: event-driven forecast and batch job workflows. These demonstrate the ability to deploy workflows across multiple platforms (GitHub Actions, Amazon Web Services Lambda, and the open-source OpenWhisk), without the need for dedicated coordination servers, across both cloud and edge resources. FaaSr is open-source and available as a CRAN package.
An in vitro evaluation of intravenous lipid emulsion on three common canine toxicants
Jones, Emery; Walton, Stuart A.; Davis, Jennifer; Council-Troche, McAlister (Frontiers, 2024-09-25)
Objective: To determine whether intravenous lipid emulsion (ILE) therapy significantly reduces the concentration of baclofen, ibuprofen, and/or bromethalin in canine whole blood over time. Animals: Seven 500 mL bags of canine DEA 1.1 negative blood were divided into aliquots of 125 mL and randomly assigned to one of three treatment groups (baclofen, ibuprofen, bromethalin) or four control groups (a positive control for each treatment group and a negative control group). Procedures: Injectable ibuprofen (200 mg/kg), baclofen (8 mg/kg), or bromethalin (3 mg/kg) was apportioned into 125 mL aliquots of canine whole blood and incubated for 30 min at 38.5°C. ILE (12.4 mL, Intralipid®) was added to each sample and the solution vortexed [215 rpm for 15 min at 37°C (98.6°F)]. Samples were obtained at designated time points (0, 15, 30, 60, 180, 360 min), centrifuged, and separated into serum and RBC fractions. Serum samples were ultracentrifuged (22,000 g for 10 min at 37°C) to separate lipid rich and poor fractions. Samples were stored at −80°C prior to analysis. Results: A significant decrease in total drug concentration was established for bromethalin and its metabolite desmethylbromethalin compared to positive controls. ILE significantly reduced desmethylbromethalin at the 30-and 360-min time points. The remainder of the desmethylbromethalin time points did not reach significance. Bromethalin concentration was significantly reduced at all time points compared to positive controls. Neither baclofen nor ibuprofen had significant changes in concentration. Conclusion: ILE therapy was effective at reducing the total drug concentration of bromethalin and its metabolite desmethylbromethalin supporting the lipid sink theory. As a single compartment in vitro study, this study does not evaluate other proposed mechanisms of action of ILE therapy. ILE therapy may have other means of significantly decreasing lipophilic drug concentration in cases of toxicosis.