Engineering Commons^™

Occurrence Of Per- And Polyfluoroalkyl Substances (Pfas) In New Hampshire Biosolids, Katherine A. Wieck

Honors Theses and Capstones

Per- and polyfluoroalkyl substances (PFAS) are a group of over 4,000 compounds used in the manufacturing of products including aqueous film forming foams for firefighting, stain repellents, waterproofing agents, and nonstick cookware since their initial development in the 1940s. The long fluorinated carbon chain structure of PFAS causes chemical and thermal stability, and thus resistance to biodegradation. Biosolids produced at wastewater facilities for uses such as agricultural land-applied compost and fertilizer for lawns and athletic fields, as well as sludge disposed in landfills can cause contamination of groundwater and surface water. This poses a significant threat to human and environmental …

Detection And Localization Of Data Forgery Attacks In Automatic Generation Control, Fengli Zhang, Yatish R. Dubasi, Wei Bao, Qinghua Li

Electrical Engineering Faculty Publications and Presentations

Automatic Generation Control (AGC) is a key control system to maintain the power system’s balance between load and supply by maintaining its frequency in a specific range. It collects the tie-line power flow and frequency measurements of each control area to calculate the Area Control Error (ACE) and then adjusts power generation based on the calculated ACE. However, malicious frequency or tie-line power flow measurements can be injected and then AGC is misled to make false power generation adjustments which will harm power system operations. Such attacks can be carefully designed to pass the power system’s existing bad data detection …

Machine Learning Predictions Of Electricity Capacity, Marcus Harris, Elizabeth Kirby, Ameeta Agrawal, Rhitabrat Pokharel, Francis Puyleart, Martin Zwick

Complex Systems Faculty Publications and Presentations

This research applies machine learning methods to build predictive models of Net Load Imbalance for the Resource Sufficiency Flexible Ramping Requirement in the Western Energy Imbalance Market. Several methods are used in this research, including Reconstructability Analysis, developed in the systems community, and more well-known methods such as Bayesian Networks, Support Vector Regression, and Neural Networks. The aims of the research are to identify predictive variables and obtain a new stand-alone model that improves prediction accuracy and reduces the INC (ability to increase generation) and DEC (ability to decrease generation) Resource Sufficiency Requirements for Western Energy Imbalance Market participants. This …

Towards Sweetness Classification Of Orange Cultivars Using Short‑Wave Nir Spectroscopy, Ayesha Zeb, Waqar Shahid Qureshi, Abdul Ghafoor, Amanullah Malik, Muhammad Imran, Alina Mirza, Mohsin Islam Tiwana, Eisa Alanazi

Articles

The global orange industry constantly faces new technical challenges to meet consumer demands for quality fruits. Instead of traditional subjective fruit quality assessment methods, the interest in the horticulture industry has increased in objective, quantitative, and non-destructive assessment methods. Oranges have a thick peel which makes their non-destructive quality assessment challenging. This paper evaluates the potential of short-wave NIR spectroscopy and direct sweetness classification approach for Pakistani cultivars of orange, i.e., Red-Blood, Mosambi, and Succari. The correlation between quality indices, i.e., Brix, titratable acidity (TA), Brix: TA and BrimA (Brix minus acids), sensory assessment of the fruit, and short-wave NIR …

Joint Probability Analysis Of Extreme Precipitation And Water Level For Chicago, Illinois, Anna Li Holey

Dissertations, Master's Theses and Master's Reports

A compound flooding event occurs when there is a combination of two or more extreme factors that happen simultaneously or in quick succession and can lead to flooding. In the Great Lakes region, it is common for a compound flooding event to occur with a high lake water level and heavy rainfall. With the potential of increasing water levels and an increase in precipitation under climate change, the Great Lakes coastal regions could be at risk for more frequent and severe flooding. The City of Chicago which is located on Lake Michigan has a high population and dense infrastructure and …

Multi-Chamber Silencer Composed Of Screw-Perforated Tubes And Straight-Perforated Tubes, Tian-Syung Lan, Min-Chie Chiu

Journal of Marine Science and Technology–Taiwan

The use of silencers to reduce noise is mandatory due to severe hearing damage caused by high venting noise in the engine room of ocean-going vessels. While straight and perforated tubes have been used as acoustical elements in traditional silencer design, studies have shown that the acoustical design still requires improvement. To enhance acoustical efficiency, the use of multi-chamber mufflers is proposed composed of screw and perforated tubes. Additionally, a mathematical finite element model built for acoustical simulation using the COMSOL program expedites the analysis of silencers with complicated acoustical elements. A sensitivity analysis of transmission loss concerning the geometric …

Rapid Species Identification Of Meretrix Lusoria And Three Other Meretrix Clams Using Pcr And Rflp Analysis Of The Mitochondrial Coii Gene., Chia-Hsuan Sung, Liang-Jong Wang, Chang-Wen Huang

Journal of Marine Science and Technology–Taiwan

Meretrix clams are among the most economically important species of bivalves in Eastern Asia and Taiwan. In the past, the identification of these hard clams depended on the shell morphology; however, species identification based on shell markings and shapes confuses the taxonomy of the Meretrix genus. The DNA molecular information is useful and can easily identify them accurately and quickly, especially the sequence of mitochondrial DNA. In this study, a PCR method to analyze the mitochondrial cytochrome c oxidase II (COII) gene was developed to rapidly identify of M. lusoria, M. lamarckii, M. lyrata and M. petechialis. Four different species …

Bearing Capacity Factor Characteristics Of Footings On Double-Layered Cohesive Soils, Chao-Ming Chi, Zheng-Shan Lin, Yu-Shu Kuo

Journal of Marine Science and Technology–Taiwan

In this study, the bearing capacity of a surface foundation resting on a double-layered cohesive soil profile was investigated by applying a rotational mechanism and finite-difference numerical simulations. The bearing capacity factor behaviors of a surface footing on double-layered cohesive soils can be classified and illustrated using a characteristic chart. Depending on the soil strata strength ratio and normalized layer thickness, the soil-foundation system can be in the squeezing, factor-increasing, factor-decreasing, or constant factor zones. The results indicated that the trend of the curves in the characteristic chart computed from the asymmetric failure mechanism was in accordance with that of …

Research On Ice Resistance Of Ships Sailing In Floating Ice Floe, Zhixin Xiong, Xinyuan Wu, Yang Li

Journal of Marine Science and Technology–Taiwan

To study the ice resistance of ships in areas with floating ice, the Xuelong 2 icebreaker was simulated. A floating-ice model was established using the discrete-element method, and an ice particle array was generated using MATLAB. The effects of ice coverage and speed on ice drag were studied From the numerical simulation results, it can be seen that there is a certain trend in ice resistance under different ice coverage ranges, which changes with the change of speed.By comparing with the empirical formula and the numerical value of the ship model test, this numerical simulation results are relatively accurate.It also …

The Pre-Processing Of Wt Blade Images By Ss And Bilateral Filter With Machine Learning Frameworks, Joy Iong-Zong Chen, Chien-Yeh Lee, Wien-Chieh Lo

Journal of Marine Science and Technology–Taiwan

This paper discusses the motivation behind turbine migration and addresses the challenges of using NN (neural network) computing systems. Moreover, it focuses on high-dimensional data from WT (wind turbine) blades. The three key aspects addressed in this study are turbine migration, overfitting, and strict feature selection. To evaluate the performance of the machine learning system, the study considers the characteristics of WT blades, specifically the similarity in blade color and the differences in shape. The authors apply pre-processing techniques, in particular a bilateral filter, in conjunction with the SS (selective synthesizer) of blade fouling patterns. The SS method adopts the …

Labile Carbon And Soil Texture Control Nitrogen Transformation In Deep Vadose Zone, Lidong Li, Jordan Shields, Daniel D. Snow, Michael Kaiser, Arindam Malakar

Daugherty Water for Food Global Institute: Faculty Publications

Understanding transient nitrogen (N) storage and transformation in the deep vadose zone is critical for controlling groundwater contamination by nitrate. The occurrence of organic and inorganic forms of carbon (C) and nitrogen and their importance in the deep vadose zone is not well characterized due to difficulty in sampling and the limited number of studies. We sampled and characterized these pools beneath 27 croplands with different vadose zone thicknesses (6–45 m). We measured nitrate and ammonium in different depths for the 27 sites to evaluate inorganic N storage. We measured total Kjeldahl nitrogen (TKN), hot-water extractable organic carbon (EOC), soil …

การจำลองกำหนดการเดินเรือโดยใช้ไทม์ออโตมาตาแบบที่มีความน่าจะเป็น, รัตชนก เธียรปุญญธนากุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในอุตสาหกรรมการขนส่งทางทะเลที่มีการจัดการด้านความเสี่ยงในการเกิดความล่าช้าในการเดินเรือตามกำหนดเป็นปัญหาที่ซับซ้อน และเกิดความเสี่ยงและเกิดค่าเสียหายผลจากถึงกำหนดล่าช้าที่จะต้องประสบกับค่าใช้จ่ายของต้นทุนที่สูงขึ้นจากปัญหาความล่าช้า จึงให้ความสนใจที่ปัญหาเหล่านี้อยู่ที่การให้ความสำคัญกับความน่าจะเป็นจากความไม่แน่นอนและเวลาในการเดินเรือ ซึ่งเป็นปัจจัยที่สำคัญในการวางแผนและจัดการตารางเดินเรือให้เหมาะสมและมีประสิทธิภาพและเหมาะสมกับเงื่อนไขและปัจจัยที่แปรผันในอุตสาหกรรมการขนส่งทางทะเล งานวิจัยนี้ จึงเล็งเห็นความสำคัญของการนำไทม์ออโตมาตาแบบที่มีความน่าจะเป็น Probabilistic Timed Automata (PTA) มาใช้ในการจำลองกำหนดการตารางเดินเรือ (Vessel Scheduling) เพื่อช่วยให้สามารถจำลองและประเมินผลของปัจจัยต่าง ๆ ที่ส่งผลต่อการเดินเรือได้อย่างเป็นระบบ และการช่วยให้ผู้วางแผนสามารถทำการปรับปรุงและวิเคราะห์ตารางเดินเรือ โดยมีผลจากการปรับปรุงค่าความนาจะเป็นและทำการทวนสอบผลที่ได้จากสถิติข้อมูลที่ใช้จำลองไม่เกิน 10% ผ่านการเขียนโปรแกรมด้วยภาษา PRISM โดยใช้ PRISM Model Checker โดยเครื่องมือสามารถจำลองพฤติกรรมการเดินเรือตามแบบจำลอง PTA ที่ออกแบบไว้ โดยคำนึงถึงปัจจัยของความน่าจะเป็นที่ส่งผลให้เกิดความล่าช้าและทำการทวนสอบด้วยสูตร PCTL ได้

Underwater Communication Acoustic Transducers: A Technology Review, Laila Shams, Tian-Bing Xu, Zhongqing Su (Ed.), Branko Glisic (Ed.), Maria Pina Limongelli (Ed.)

Mechanical & Aerospace Engineering Faculty Publications

This paper provides a comprehensive review on transducer technologies for underwater communications. The popularly used communication transducers, such as piezoelectric acoustic transducers, electromagnetic acoustic transducers, and acousto-optic devices are reviewed in detail. The reasons that common air communication technologies are invalid die to the differences between the media of air and water are addresses. Because of the abilities to overcome challenges the complexity of marine environments, piezoelectric acoustic transducers are playing the major underwater communication roles for science, surveillance, and Naval missions. The configuration and material properties of piezoelectric transducers effects on signal output power, beamwidth, amplitude, and other properties …

N-Cylindrical Fuzzy Neutrosophic Topological Spaces, Sarannya Kumari R, Sunny Joseph Kalayathankal, Mathews George, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

The objective of this study is to incorporate topological space into the realm of n-Cylindrical Fuzzy Neutrosophic Sets (n-CyFNS), which are the most novel type of fuzzy neutrosophic sets. In this paper, we introduce n-Cylindrical Fuzzy Neutrosophic Topological Spaces (n-CyFNTS), n-Cylindrical Fuzzy Neutrosophic (n-CyFN) open sets, and n-CyFN closed sets. We also defined the n-CyFN base, n-CyFN subbase, and some related theorems here.

Using Unmanned Aircraft Systems To Investigate The Detectability Of Burmese Pythons In South Florida, Joseph Cerreta, William Austin, David Thirtyacre, Scott S. Burgess, Peter Miller

Journal of Aviation/Aerospace Education & Research

Burmese pythons are an invasive, non-native species of snake to southern Florida and attempts at eradicating the snakes had yielded mixed results. The current rate of detection had been reported as 0.05%. The purpose of this research project was to determine if a UAS equipped with a near-infrared (NIR) camera could be used to detect pythons at a higher rate when compared to a RGB camera. The approach involved collecting 55 images from RGB and NIR cameras, over carcass pythons at flying heights of 3, 6, 9, 12, and 15 meters. A likelihood ratio consisting of a true positive rate …

Mitigating Supply Chain Disruptions In Retail Discount Department Stores, Anthony T. Patton

Walden Dissertations and Doctoral Studies

Supply chain disruptions can have adverse effects on business outcomes. Retail industry supply chain leaders are concerned with supply chain disruptions because supply chain disruptions can lead to dissatisfied customers and loss of profits. Grounded in game theory, the purpose of this multiple case study was to explore strategies four retail industry supply chain leaders in Northern Illinois and Northwest Indiana implemented to mitigate the effects of supply chain disruptions. Data were collected using semistructured virtual interviews with four retail industry supply chain leaders and a review of company documents. Through thematic analysis, four themes emerged: (a) choosing appropriate inventory …

Ai Usage In Development, Security, And Operations, Maurice Ayidiya

Walden Dissertations and Doctoral Studies

Artificial intelligence (AI) has become a growing field in information technology (IT). Cybersecurity managers are concerned that the lack of strategies to incorporate AI technologies in developing secure software for IT operations may inhibit the effectiveness of security risk mitigation. Grounded in the technology acceptance model, the purpose of this qualitative exploratory multiple case study was to explore strategies cybersecurity professionals use to incorporate AI technologies in developing secure software for IT operations. The participants were 10 IT professionals in the United States with at least 5 years of professional experience working in DevSecOps and managing teams of at least …

3d Printed Microfluidic Devices For Advanced Fluid Manipulation In Biomedical Applications, Kathrine Curtin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Microfluidics are valuable devices in the biomedical field because of their remarkable ability to manipulate small volumes of fluid and facilitate reactions. Microfluidics have several significant advantages, including their portability, low cost, fast reaction times, and high surface area-to-volume ratios. Microfluidics be used for a multitude of applications, including bioanalysis, cellular assays, organ-on-a-chip, and separations. Microfluidics have great potential to overcome many challenges in conventional chemical and biological applications. However, complex fabrication procedures in silicon, glass, thermoplastics, and (polydimethylsiloxane) PDMS devices make rapidly optimizing and prototyping devices challenging. Microfluidic fabrication techniques have been a long-standing challenge in successfully translating these …

Finite Element Modeling And Analysis Of Breech Face Impressions, James A. Hamilton

Graduate Theses, Dissertations, and Problem Reports (ETD)

Finite element analysis (FEA) is a technique which has not been widely used in Forensic Science in general and firearms examination in particular. The general utility of FEA was assessed by the simulation of scenarios commonly encountered during the investigation of firearm related crimes. As a test, simulations included the perforation of a windshield and sheet metal with a 9 mm projectile, the development of pseudo subclass characteristics during the manufacturing of a breech face, and the impact of a projectile with another projectile in air and with a solid body. Results from the simulations were compared to projectiles and …

Probabilistic Short Term Solar Driver Forecasting With Neural Network Ensembles, Joshua Daniell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Commonly utilized space weather indices and proxies drive predictive models for thermosphere density, directly impacting objects in low-Earth orbit (LEO) by influencing atmospheric drag forces. A set of solar proxies and indices (drivers), F_10.7, S_10.7, M_10.7, and Y_10.7, are created from a mixture of ground based radio observations and satellite instrument data. These solar drivers represent heating in various levels of the thermosphere and are used as inputs by the JB2008 empirical thermosphere density model. The United States Air Force (USAF) operational High Accuracy Satellite Drag Model (HASDM) relies on JB2008, and …

Ambient Ammonia Synthesis Via Microwave-Catalytic Materials And Plasma Chemistry, Siobhan Brown

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ammonia is critical to supporting human life on earth because of its use as fertilizer. The Haber-Bosch process to produce ammonia has been practiced for over 100 years. This process operates at high pressure and temperature to overcome the thermodynamic and kinetic limitations of the ammonia synthesis reaction thus researchers have tried to overcome it for decades. At present this process represents 1% of global energy usage and 2.5% of global CO₂ emissions. The proposed chemical looping ammonia synthesis approach seeks to reduce the environmental impact of this critical process and to elucidate microwave-catalytic principles.

This research aims to …

Optimal Design And Operation Of Integrated Hydrogen Generation And Utilization Plants, Ijiwole Solomon Ijiyinka

Graduate Theses, Dissertations, and Problem Reports (ETD)

There are considerable efforts worldwide for reducing the use of fossil fuel for energy production. While renewable energy sources are being increasingly used, fossil fuel still contribute about 80% of the energy used worldwide. As a result, the level of CO₂ is still increasing fast in the atmosphere currently exceeding about 410 parts per million (ppm). For reducing CO₂ build up in the atmosphere, various approaches are being investigated. For the electric power generation sector, two key approaches are post-combustion CO₂ capture and use of hydrogen as a fuel for power generation. These two solutions can also …

Development Of A Framework To Support Community-Scale Nutrient Recovery For Local Crop Fertilization And Production, Scott A. Lopez

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nutrient and resource recovery (NRR) has become increasingly crucial as regions face deteriorating sanitation infrastructures, limited support, and growing environmental challenges. Implementing region-specific NRR technologies and systems could provide effective circular economy insights into addressing these challenges. Because of the multidisciplinary challenges associated with the design and implementation of NRR strategies, various government and local decision-makers need to collaborate effectively in the decision-making process. Structured decision-making (SDM) methodologies are practical when determining the most appropriate NRR strategy for nutrient-rich waste streams. However, applications of computational SDM limited because of the vast amounts of data that are needed to analyze the …

Comparative Adjudication Of Noisy And Subjective Data Annotation Disagreements For Deep Learning, Scott David Williams

Browse all Theses and Dissertations

Obtaining accurate inferences from deep neural networks is difficult when models are trained on instances with conflicting labels. Algorithmic recognition of online hate speech illustrates this. No human annotator is perfectly reliable, so multiple annotators evaluate and label online posts in a corpus. Labeling scheme limitations, differences in annotators' beliefs, and limits to annotators' honesty and carefulness cause some labels to disagree. Consequently, decisive and accurate inferences become less likely. Some practical applications such as social research can tolerate some indecisiveness. However, an online platform using an indecisive classifier for automated content moderation could create more problems than it solves. …

Enhancing Graph Convolutional Network With Label Propagation And Residual For Malware Detection, Aravinda Sai Gundubogula

Browse all Theses and Dissertations

Malware detection is a critical task in ensuring the security of computer systems. Due to a surge in malware and the malware program sophistication, machine learning methods have been developed to perform such a task with great success. To further learn structural semantics, Graph Neural Networks abbreviated as GNNs have emerged as a recent practice for malware detection by modeling the relationships between various components of a program as a graph, which deliver promising detection performance improvement. However, this line of research attends to individual programs while overlooking program interactions; also, these GNNs tend to perform feature aggregation from neighbors …

Effective Systems For Insider Threat Detection, Muhanned Qasim Jabbar Alslaiman

Browse all Theses and Dissertations

Insider threats to information security have become a burden for organizations. Understanding insider activities leads to an effective improvement in identifying insider attacks and limits their threats. This dissertation presents three systems to detect insider threats effectively. The aim is to reduce the false negative rate (FNR), provide better dataset use, and reduce dimensionality and zero padding effects. The systems developed utilize deep learning techniques and are evaluated using the CERT 4.2 dataset. The dataset is analyzed and reformed so that each row represents a variable length sample of user activities. Two data representations are implemented to model extracted features …

Fuzzing Php Interpreters By Automatically Generating Samples, Jacob S. Baumgarte

Browse all Theses and Dissertations

Modern web development has grown increasingly reliant on scripting languages such as PHP. The complexities of an interpreted language means it is very difficult to account for every use case as unusual interactions can cause unintended side effects. Automatically generating test input to detect bugs or fuzzing, has proven to be an effective technique for JavaScript engines. By extending this concept to PHP, existing vulnerabilities that have since gone undetected can be brought to light. While PHP fuzzers exist, they are limited to testing a small quantity of test seeds per second. In this thesis, we propose a solution for …

Human Tracking Function For Robotic Dog, Andrew Sharkey

Williams Honors College, Honors Research Projects

With the increase the increase in automation and humans and robots working side by side, there is a need for a more organic way of controlling robots. The goal of this project is to create a control system for Boston dynamics robotic dog Spot that implements human tracking image software to follow humans using computer vision as well as using hand tracking image software to allow for control input through hand gestures.

Intergranular And Pitting Corrosion Mechanisms Of Sensitized Aluminum Alloy Aa5083, Clayton Egleston

Williams Honors College, Honors Research Projects

The motivation and objectives of this project is to examine the mechanisms of intergranular corrosion (IGC) and pitting corrosion of sensitized AA5083. In this regard, different characterization techniques were used, including optical analysis of microstructure, cyclic potentiodynamic polarization with Tafel fitting, electrochemical impedance spectroscopy with electrical equivalent circuit (EEC) fitting, and potentiostatic current transient monitoring. The transition from IGC to pitting corrosion occurs when the grain boundaries become saturated with the β-phase (Mg₂Al₃). It was found that AA5083 becomes more vulnerable to pitting corrosion as the degree of sensitization increases.

Improving Developers' Understanding Of Regex Denial Of Service Tools Through Anti-Patterns And Fix Strategies, Sk Adnan Hassan, Zainab Aamir, Dongyoon Lee, James C. Davis, Francisco Servant

Department of Electrical and Computer Engineering Faculty Publications

Regular expressions are used for diverse purposes, including input validation and firewalls. Unfortunately, they can also lead to a security vulnerability called ReDoS (Regular Expression Denial of Service), caused by a super-linear worst-case execution time during regex matching. Due to the severity and prevalence of ReDoS, past work proposed automatic tools to detect and fix regexes. Although these tools were evaluated in automatic experiments, their usability has not yet been studied; usability has not been a focus of prior work. Our insight is that the usability of existing tools to detect and fix regexes will improve if we complement them …