Master's Papers and Projects
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- Design and Performance Analysis of Quadfoil: A Novel Aerofoil-Shaped DroneDeshmukh, Sarthak Dinesh (Virginia Tech, 2024-09-25)This project presents a comprehensive exploration of the Quadfoil drone, an innovative quadrotor design developed by the Uncrewed Systems Laboratory (USL) at Virginia Tech to address limitations of traditional quadcopters. Unlike conventional quadrotors, which rely solely on rotor-generated lift, the Quadfoil features a central lifting body, enhancing aerodynamic efficiency by reducing drag and generating additional lift during forward flight. This design results in an approximate 27% increase in efficiency at optimal forward flight speeds, enabling extended range and endurance while retaining essential VTOL (Vertical Take-Off and Landing) capabilities. The study begins with a literature review of UAV design evolution, detailing advancements from basic quadrotor models to contemporary hybrid UAVs and aerodynamic structures. Following this, the design and development process of the Quadfoil is discussed, including critical decisions on airfoil selection, materials, and structural innovations to optimize for low Reynolds number flight conditions. Key elements of the design include the use of carbon fiber composites for weight reduction and enhanced structural integrity, as well as the selection of the ARA-D 20% airfoil for its favorable lift-to-drag ratio. The Quadfoil’s innovative design also allows for significant internal space, facilitating the integration of advanced electronics and avionic systems. The research includes extensive experimental flight testing to assess the Quadfoil’s performance in terms of energy efficiency, power consumption, and flight dynamics. These tests demonstrated the Quadfoil’s ability to maintain lower power consumption in sustained forward flight compared to a conventional quadcopter, with a notable improvement in energy efficiency. Data gathered from the proof-of-concept prototype and scaled-up iterations is thoroughly analyzed, identifying areas for further optimization. The findings conclude with a discussion on the Quadfoil’s broader implications for UAV technology. The research highlights potential applications in fields such as surveillance, cargo transport, and critical medical payload delivery, showcasing the Quadfoil’s advantages in both range and endurance. The project aims to contribute to the advancement of UAV technology by providing a solid foundation for continued innovation and development.
- Effects of Diet Change on Shelter Dog Kennel Behaviors and Cortisol LevelsBoris, Samantha; Oberding, Natalie; Mercadante, Paula; Kerr, Anna; Andrukonis, Allison; Feuerbacher, Erica N. (Virginia Tech, 2024)Ketogenic diets have shown beneficial behavior effects as well as decreases in stress in mice and humans; however, this has not been empirically evaluated in dogs. The purpose of this study was to investigate if a ketogenic diet would be effective in reducing kennel reactivity, with a focus on barking, and cortisol levels in shelter dogs that currently display kennel reactivity. We placed 33 shelter dogs on a ketogenic diet over our nine-week study period (two weeks of a gradual diet change and four weeks on a full ketogenic diet). We collected one minute video recordings for the dogs twice every collection day for a total of eight videos over our four collection periods during Weeks 0, 3, 6, and 9. Of the 18 behaviors we analyzed, six significantly differed between the baseline and treatment phases. The positive behavior change we saw was a decrease in barking during treatment compared to baseline. Despite seeing a positive effect on barking, several affiliative behaviors observed in our study showed a significant decrease from baseline to treatment (facing forward, front of kennel, gazing, and wagging tail) while facing away increased during treatment. To assess the effect of diet on cortisol levels, we collected four fecal samples starting with Week 0 and then one every three weeks after during the nine-week study period. We found a significant decrease in fecal cortisol levels between baseline and treatment phases. In summary, we saw changes in cortisol levels to indicate decreases of stress when on a ketogenic diet, as well as a decrease in our main target behavior, barking. The results indicate something as simple as a change in diet is a feasible intervention for shelters to implement in real time to address in-kennel behavior issues, such as barking.
- The Influence of Flight Speed, Image Overlap, and Lighting Conditions on the Spatial Accuracy and Development Time of Low-Cost UAS ImagingHower, Madeline (Virginia Tech, 2024)Widespread emerging UAV technology has resulted in an increased use of drones across a variety of fields to complete mapping and surveying evaluations. However, accessible guidelines providing information on the effects parameter choices and environmental considerations have on orthomosaic quality and accuracy do not exist. To improve the understanding of the various influences on mapping results, this study evaluates how image overlap ratio, mapping speed, and lighting conditions affect spatial accuracy and development time for resulting orthomosaic images. This evaluation was done by conducting mapping missions with several parameter variations over a homogeneous area and a non-homogeneous area. The accuracy was assessed by calculating the root mean square error (RMSE). The results suggest that effects of mapping parameters differ between homogeneous and non-homogeneous areas. For a homogeneous location, the most accurate conditions were obtained by conducting mapping on a clear weather day, with a 60/80 overlap, at a mapping speed of 3 m/s. For the non-homogeneous location, the most accurate conditions were conducting mapping on a cloudy weather day, with a 70/80 overlap, at a mapping speed of 5m/s. A correlation was also found between lighting conditions and image development time and between image overlap and image development time, where clear day weather resulted in a lower processing time and reducing front overlap had the greatest reduction in processing time.
- Evaluative Thinking: Addressing Complex Adaptive Challenges in the Agricultural Cybersecurity WorkforceSamson O. Adeoye (2023-04-24)Humans are the weakest links in cybersecurity, but this knowledge has not been well channeled into capacity building toward improving agriculture and food organizations’ workforce resilience in forestalling cyberattacks. Many capacity-building endeavors have focused on technical dimensions, neglecting the role of critical evaluative thinking, and ignoring the reality that cybersecurity is a wicked problem that confounds technical expertise. The consequence of this is the persistent attacks by cyber-criminal actors exploring social engineering to disrupt operational processes, cause financial and data losses, and breach the food supply chain. The long-term impacts of these attacks suggest a bleak future for the continued natural existence of humans, animals, and plants on the planet. Agriculture and life sciences organizations, particularly those leveraging artificial intelligence (AI), big data, and the Internet of Things (IoTs) to support industrial control systems in their operations are struggling with handling the complex adaptive challenges that cybersecurity poses. Using a conceptual framework, this presentation demonstrates how evaluative thinking can be adapted as a way of doing agriculture business in the digital world. Indeed everyone needs to be a knowledge worker in these perilous times and developing an evaluation culture through evaluative thinking is a precursor to knowledge-working. Evaluative thinking can help individuals and organizations to critically and systemically build the evaluation logic into programmatic efforts to safeguard agricultural systems and enhance the identification, prevention, assessment, and mitigation of cyber intrusions.
- Developing a FISH-based Method for Inversion Diagnostics in Culex pipiens MosquitoesHartigan, Daniel P.; Sharakhova, Maria V. (2023-07-25)This project developed an improved protocol for the dissections of imaginal discs from 4th instar Culicine larvae. The design of the protocol and use of visuals have now allowed dissections to be more accessible and streamline the learning process for undergraduate students or new lab members. The new protocol is important for instructional use in laboratories and classrooms with the aim of studying mitotic chromosomes isolated from mosquito larvae. For this project, probes were designed for diagnostics for the Chromosome 1 inversion 1p3” and the Chromosome 2 inversion 2q1 for the field-collected strains Cx. p. pipiens Northfield strain, Cx. p. molsestus Chicago strain, and the genomic standard JHB strain of Cx. quinquefasciatus. Primers were developed and used in PCR and produced products ranging between 3,000 and 4,500kb that are suitable for subsequent labeling by Nick Translation method and visualization of the status of inversions using Fluorescent in situ Hybridization (FISH). Lastly, a FISH-based approach for the detection of the chromosome 1 inversion, 1p3” was optimized for the mitotic chromosomes from the imaginal discs for the standard genomic strain JHB of Cx. quinquefasciatus. Two probes produced clear signals indicating a standard arrangement for this inversion in the chromosome 1 of this strain. This shows that probes developed for FISH-based inversion diagnostics using mitotic chromosomes have the potential for further method development.
- Out-of-Classroom Student Engagement at Virginia Tech: The Effects of Race, Gender, and Class Year on Engagement Levels and Their Use as Predictors of Students’ GradesWilliams, Jaime L. (Virginia Tech, 2008-12-17)Engagement is one of the better predictors of learning and personal development among college students. College and university studies have identified differences in student engagement based upon demographic variables associated with students (Harper, Carini, Bridges, & Hayek, 2004; Kezar, 2006; Laird, et al., 2007). The Division of Student Affairs at Virginia Tech was interested in out-of-classroom engagement levels of students based on race, gender, and class standing, and wanted to determine if student engagement could serve as a significant predictor of students’ grades. The findings revealed that: - Virginia Tech students are highly engaged in exercise activities, practicum or internship experiences, and community service and volunteer work - Majority students participated in physical fitness activities significantly more frequently than underrepresented students; however, underrepresented students participated in artistic activities more frequently than majority students - Women were significantly more likely than men to report planned or actual participation in artistic activities, internships, community service work, and study abroad programs, whereas men were more likely to participate in physical fitness activities - First-year students were significantly more likely to report planned or actual participation in artistic events, internships, community service work, learning communities, and study abroad programs - Physical fitness activities as well as planned or actual participation in internships and study abroad programs had a positive influence on students’ grades. Based on these findings, an increased awareness of study abroad programs at Virginia Tech is recommended. In addition, it is advised that Residential Life develop a strategic plan for making learning communities a requirement of first-year students, and that Recreational Sports develop assessment to determine the reasons for higher majority student participation in physical fitness activities.
- The Design, Manufacturing, and Testing of a Novel Blended Wing Body Multirotor UAV for Public Safety ApplicationsMoncure, Katie M. (2023-05-12)Virginia Tech’s Uncrewed Systems Lab (USL) has begun development of a small quadcopter with a novel aerodynamic design intended for public health and safety applications. An ever-increasing number of regulations against Chinese technology in the US has forced many public safety agencies to ground their fleets and seek new alternatives. The USL team and our partners wish to fill this hole in the market. The final product is envisioned as being a monocoque composite blended wing body (BWB) quadcopter, compatible with a wide range of payload types and comprised of only non-Chinese components. Based on market research and a literature review, the team believes that these features will significantly enhance the aerodynamic efficiency, structural reliability, repairability, and versatility of our product compared to currently available solutions, and that these features are what the customer base need in their solution. Thus far, the USL has already shown that the design has significantly better energy efficiency than comparable vehicles due to its unique, wing-shaped fuselage. A prototype was designed and constructed for proof of concept and configuration testing. Proof of concept testing showed great promise. The prototype was flight tested and compared to a Holybro S500, and found to be significantly more energy efficient, particularly at higher speeds. This is highly promising, and thus, work will continue on optimizing and maturing this design. The next steps include arm configuration testing and downselection followed by building a composite prototype. The team at VT’s USL has high hopes for making this an actual product that will be profitable and beneficial to society by catering to public safety and law enforcement customers in the United States.
- Aluminum Fatigue: A literature review covering its influence on engineering from design to end of serviceFarmer, Stephen M. (Virginia Tech, 2022-12-20)This article is an examination of the field of fatigue research on aluminum alloys. It covers the historical development of the field of fatigue from its creation in the 1830s to modern times. The remainder of the paper is a survey on aluminum fatigue and research that covers the entire span of the design process. This includes research into the effects of manufacturing methods on the fatigue of parts and alloys. This is followed by analysis on methods of monitoring fatigue damage while a system is in service including sensors, methods of inspection as well as structural health monitoring systems and how they contribute to the understanding of fatigue or the mitigation of its effects. Additionally, methods of maintenance and repair are examined with focus the mechanisms they exploit to retard crack propagation and extend the fatigue lifetime of the part or system. Overarching themes of analysis across all areas covered include the motivation of the research as to whether it is meant to advance the understanding of the mechanisms of fatigue or to compensate for the lack of understanding of these mechanisms.
- Comparative Pan-Genomic Analysis Revealed an Improved Multi-Locus Sequence Typing Scheme for Staphylococcus aureusJalil, Maira; Quddos, Fatima; Anwer, Farha; Nasir, Samavi; Rahman, Abdur; Alharbi, Metab; Alshammari, Abdulrahman; Alshammari, Huda Kamel; Ali, Amjad (MDPI, 2022-11-19)The growing prevalence of antibiotic-resistant Staphylococcus aureus strains mandates selective susceptibility testing and epidemiological investigations. It also draws attention to an efficient typing strategy. Whole genome sequencing helps in genetic comparison, strain differentiation, and typing; however, it is not that cost-effective. In comparison, Multi-Locus Sequence Typing (MLST) is an efficient typing method employed for bacterial strain typing and characterizations. In this paper, a comprehensive pangenome and phylogenetic analysis of 502/1279 S. aureus genomes is carried out to understand the species divergence. Additionally, the current Multi-Locus Sequence Typing (MLST) scheme was evaluated, and genes were excluded or substituted by alternative genes based on reported shortcomings, genomic data, and statistical scores calculated. The data generated were helpful in devising a new Multi-Locus Sequence Typing (MLST) scheme for the efficient typing of S. aureus strains. The revised scheme is now a blend of previously used genes and new candidate genes. The genes yQil, aroE, and gmk are replaced with better gene candidates, opuCC, aspS, and rpiB, based on their genome localization, representation, and statistical scores. Therefore, the proposed Multi-Locus Sequence Typing (MLST) method offers a greater resolution with 58 sequence types (STs) in comparison to the prior scheme’s 42 STs.
- Frequency response of a feed preheaterJanis, Rudolph Francis (Virginia Polytechnic Institute, 1962)The purpose of this investigation was to measure the frequency response of a shell and tube heat exchanger when the input is the pressure to the steam valve and the output is the feed temperature. During this investigation the frequency response of the feed flow loop was also determined. Controller settings were determined for the feed rate controller. The heat-exchanger under investigation was the food preheater connected to the ten place, bubble-cap, distillation column located in the Unit Operations Laboratory, Department of Chemical Engineering, Virginia Polytechnic Institute. This heat-exchanger was a single-pass, shell and tube type having a contact surface of nineteen 5/8-inch copper tubes 45.5 inches long. The flow rate during the investigation of temperature and pressure frequency response was maintained at 3.70 gallons per minute. The feed mixture was composed of benzene, n-hepane, xylene, and toluene. Frequency response tests were conducted on the steam pressure and hydrocarbon temperature to upsets in steam flow rates. Two tests were conducted on each the temperature and pressure. The first test was conducted at a mean temperature of 161°F and the second at 194°F. The frequency range for each of these tests was 0.008 - 0.05 cycles per second. The ultimate frequency of the hydrocarbon temperature to steam flow upsets was determined to be 0.021 cycles per second. Frequency response test performed on the feed flow loop was conducted at a mean hydrocarbon flow rate of 2.75 gallons per minute and room temperature. A fifteen percent disturbance was used and the unit was tested over the frequency range of 0.008 - 0.6 cycles per second. The zero frequency gain of the feed flow loop was found to be 2.10. The ultimate frequency for upsets in flow was determined to be 0.53 cycles per second. The controller settings determined for the two mode controller which controlled the hydrocarbon flow were, proportional band of 63.5 percent and reset of 0.262 minutes.
- A study of the self-purification of Strouble's CreekSutton, Lee Edwards (Virginia Agricultural and Mechanical College and Polytechnic Institute, 1914)
- A report of an investigation of a portion of Strouble's Creek, near Blacksburg, Montgomery County, VirginiaFowle, Bernard H. (Virginia Agricultural and Mechanical College and Polytechnic Institute, 1913)A report of an investigation of a portion of Strouble’s Creek, near Blacksburg, Montgomery County, Virginia, for the purpose of locating a reservoir to serve as a source of ice supply for the Virginia Polytechnic Institute, as a skating pond for the cadets of the Institute and as a possible source of water supply for the Tuberculosis Barns of the Virginia Agricultural Experiment Station, located nearby. This report will include a study of the topography of the portion of trouble's Creek Valley involved, of the water flow conditions of this stream, of complete designs for a Hollow Deck and Buttress Type of Reinforced Concrete Dam, and cost estimates on the proposition. This report will be accompanied by a complete topographic map of the area involved, the field notes, and complete plans for the Hollow Deck and Buttress Type of Dam decided on, save that the 36" pipe and control valve for the drainage of the reservoir are not shown.
- Comparative Analysis of Facial Affect Detection AlgorithmsThomas, Ashin Marin (2020-05-22)There has been much research on facial affect detection, but many of them fall short on accurately identifying expressions, due to changes in illumination, occlusion, or noise in uncontrolled environments. Also, not much research has been conducted on implementing the algorithms using multiple datasets, varying the size of the dataset and the dimension of each image in the dataset. My ultimate goal is to develop an optimized algorithm that can be used for real-time affect detection of automated vehicles. In this study, I implemented the facial affect detection algorithms with various datasets and conducted a comparative analysis of performance across the algorithms. The algorithms implemented in the study included a Convolutional Neural Network (CNN) in Tensorflow, FaceNet using Transfer Learning, and Capsule Network. Each of these algorithms was trained using the three datasets (FER2013, CK+, and Ohio) to get the predicted results. The Capsule Network showed the best detection accuracy (99.3%) with the CK+dataset. Results are discussed with implications and future work.
- Utilization of the Tyndall beam in cellulose processingMyers, Robert Frederick (Virginia Agricultural and Mechanical College and Polytechnic Institute, 1936)no abstract provided by author
- Regression analysis of extended vectors to obtain coefficients for use in probabilistic information retrieval systemsNunn, Gary L. (Virginia Polytechnic Institute and State University, 1987)Previous work by Fox has extended the vector space model of information retrieval and its implementation in the SMART system so different types of information about documents can be separately handled as multiple subvectors, each for a different concept type. We hypothesized that relevance of a document could be best predicted if proper coefficients are obtained to reflect the importance of the query-document similarity for each subvector when computing an overall similarity value. Two different research collections, CACM and ISI, each split into halves, were used to generate data for the regression studies to obtain coefficients. Most of the variance in relevance could be accounted for by only four of the subvectors (authors, Computing Review descriptors, links, and terms) for the CACM1 collection. In the ISI1 collection, two of the vectors (terms and cocitations) accounted for most of the variance. Log transformed data and samples of the records gave the best RSQ's; .6654 was the highest RSQ (binary relevance). The regression runs provided coefficients which were used in subsequent feedback runs in SMART. Having ranked relevance did not improve the regression model over binary relevance. The coefficients in the feedback runs with SMART proved to be of limited usefulness since improvements in precision were in the 1-5% range. Although log data and samples of the records gave the best RSQ's, coefficients from log values of all data improved precision the most. The findings of this study support previous work of Fox, that additional information improves retrieval. Regression coefficients improved precision slightly when used as subvector weights. Log transforming the data values for the concept types modestly helped both the regression analyses and the retrieval in SMART.
- A computer program in hydrology for landscape architectureQuillen, Timothy R. (Virginia Polytechnic Institute and State University, 1987)
- The effect of space launch vehicle trajectory parameters on payload capability and their relation to interplanetary mission designLovell, Julius Burt (Virginia Polytechnic Institute, 1969)
- Auragami: Unfolding Stereo Audio for High-Density Loudspeaker ArraysUpthegrove, John Tanner (2019-05-14)As a critical complement to immersive music, especially in virtual and augmented reality, demand for high-density loudspeaker arrays (HDLAs), consisting of 24 or more individually addressable loudspeakers is increasing. With only a few dozen publicly accessible systems around the world, HDLAs are rare, necessitating artistic and technical exploration. The work presented in this thesis details the culmination of four years of aesthetic and technical practice in composition and sound design for high-density loudspeaker arrays as an attempt to solidify existing standards and posit new practices. technical achievements include a pipeline to create repeatable and portable spatial audio mixes across arbitrary loudspeaker arrays, rapid spatial sound prototyping, and digital audio workstation workflow for 3-D soundscape creation. Aesthetic explorations have resulted in a distinct compositional voice, utilizing spatial audio systems as an instrument. Compositions specific to one venue may take advantage of the unique characteristics of a venue, such as loudspeaker layout, loudspeaker quantity, and room acoustics. The detailed graduate projects from 2015 to 2019 exemplify technical and compositional achievements in the exploration of the potential for HDLAs.
- The design of spoil banks and hollow fills for surface miningBeggs, Duane (Virginia Polytechnic Institute and State University, 1979)no abstract provided by author
- Assessment of the health knowledge of tenth graders in the Portsmouth, Virginia, public school systemRunyon, Debra Darley (Virginia Polytechnic Institute and State University, 1984)