Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Missouri University of Science and Technology

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 541 - 570 of 10902

Full-Text Articles in Entire DC Network

Molecular Imaging Nanoprobes And Their Applications In Atherosclerosis Diagnosis, Huari Kou, Hu Yang Jan 2024

Molecular Imaging Nanoprobes And Their Applications In Atherosclerosis Diagnosis, Huari Kou, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Molecular imaging has undergone significant development in recent years for its excellent ability to image and quantify biologic processes at cellular and molecular levels. Its application is of significance in cardiovascular diseases, particularly in diagnosing them at early stages. Atherosclerosis is a complex, chronic, and progressive disease that can lead to serious consequences such as heart strokes or infarctions. Attempts have been made to detect atherosclerosis with molecular imaging modalities. Not only do imaging modalities develop rapidly, but research of relevant nanomaterials as imaging probes has also been increasingly studied in recent years. This review focuses on the latest developments …


Magnetic Separation Of Lunar Regolith Simulants With Applications To In Situ Resource Utilization On The Moon, Peter Bachle, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han Jan 2024

Magnetic Separation Of Lunar Regolith Simulants With Applications To In Situ Resource Utilization On The Moon, Peter Bachle, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han

Chemical and Biochemical Engineering Faculty Research & Creative Works

The development of in situ resource utilization (ISRU) for metal extraction is imperative as a steppingstone for habitation construction in lunar and non-terrestrial environments. Separation of minerals by chemical composition is important to optimize metal and oxygen liberation from lunar ore. To this effect, devices capable of separating aluminum bearing minerals from iron-bearing minerals from the lunar regolith simulants have been developed. Twenty-eight different simulants have been used in this study. A dual-belt separator was designed to reduce middling. Para-magnetic minerals were reliably separated using a neodymium N52-magnet-separator system. Effective separation of aluminum-bearing minerals from iron-bearing minerals was greater than …


Towards Explainability Of Dimension Reduction Plots Of Unsupervised Learning Model Outcomes, Tony E.Astuhuaman Davila, Daniel B. Hier, Tayo Obafemi-Ajayi Jan 2024

Towards Explainability Of Dimension Reduction Plots Of Unsupervised Learning Model Outcomes, Tony E.Astuhuaman Davila, Daniel B. Hier, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

Dimension reduction methods are used to visualize the output of unsupervised learning models when applied to complex data. These techniques improve interpretability by transforming a high-dimension space to a lower-dimension space (usually 2D or 3D). The results are typically viewed as 2D scatter plots, and class centroids may be added to increase interpretability. Although useful, the relationship of these class centroids to the underlying feature space remains opaque. The innovative aspect of this work is to create a strong link between the dimension-reduced space and the underlying high-dimension feature space by adding selected feature centroids to the 2D scatter plots. …


Cryptographic Algorithms, Cryptocurrencies, And A Predictive Model Of Bitcoin Value By Pls Regression, Paul Kenneth O'Connor Jan 2024

Cryptographic Algorithms, Cryptocurrencies, And A Predictive Model Of Bitcoin Value By Pls Regression, Paul Kenneth O'Connor

Masters Theses

"With the invention of Bitcoin in 2009, as a seemingly timed response to the ongoing financial crisis, the popularity of the cryptocurrency has since continued to grow. Just this year, the Security Exchange Commission approved Bitcoin for exchange traded funds, allowing major investment firms to begin product trading. With this approval, and during this very moment of writing, Bitcoin has entered a bull market and reached a record value of over 72,000 USD. In addition, the Bitcoin halving event in April of 2024 is expected to increase demand even further. It has been anticipated that Bitcoin and other cryptocurrencies will …


Theoretical Modeling And Experimental Investigation Of Phase Selection During Rapid Solidification Of Alloys, Azeez Aremu Akinbo Jan 2024

Theoretical Modeling And Experimental Investigation Of Phase Selection During Rapid Solidification Of Alloys, Azeez Aremu Akinbo

Masters Theses

"A novel model, rooted in time-dependent nucleation theory, has been created to explore how rapid solidification affects the extended solubility in metal alloys. This model was used to forecast solubility concerning undercooling in multiple binary aluminum (Al) alloys, and its predictions for both eutectic and peritectic systems closely match experimental data. It was demonstrated that this developed model surpasses the T0 line method, which does not consider the kinetic aspects of nucleation. Furthermore, the model can be extended to ternary and multicomponent phases by assuming that the scarcest element or the slowest diffusing component restricts nucleation. Al-Cu and Al-Cr, vital …


Development And Characterization Of An Ion Source To Simulate Low Earth Orbit Plasma Environment In A Vacuum Chamber, Emmanuel Kofi Asuako Wie-Addo, Scott Lucas, Daoru Han Jan 2024

Development And Characterization Of An Ion Source To Simulate Low Earth Orbit Plasma Environment In A Vacuum Chamber, Emmanuel Kofi Asuako Wie-Addo, Scott Lucas, Daoru Han

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A magnetic filter-type plasma source has been installed and characterized in a 10 ft long x 6ft diameter vacuum chamber. The plasma source was characterized with a fleet of diagnostic probes including an in-house cylindrical Langmuir probe. This resulted in the measurement of key plasma parameters such as electron number density, electron temperature, plasma potential, Debye length, ion current density, streaming ion energy, ion number density, and streaming ion velocity. By varying the flow rates, discharge current, and distance, single points measurements were taken at three locations downstream of the plasma source to establish an optimum operating condition to simulate …


An Unsupervised Learning Framework For Determining The Excitation Coefficients Using Near-Field Antenna Measurements, Yanming Zhang, Peifeng Ma, Steven Gao, Lijun Jiang Jan 2024

An Unsupervised Learning Framework For Determining The Excitation Coefficients Using Near-Field Antenna Measurements, Yanming Zhang, Peifeng Ma, Steven Gao, Lijun Jiang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This article presents a novel unsupervised learning framework based on multiscale dynamic mode decomposition for determining the excitation coefficients of antennas using time-domain near-field measurements. The proposed framework integrates temporal multiscale analysis to extract a joint distribution of frequency, damping factors, and spatial modes, enabling precise extraction of excitation frequencies, rising/falling edges, and phases without labeled data. We validate the effectiveness of the proposed approach through two examples involving on-off keying modulation and a phase-shift dipole antenna. It is found that the proposed method performs well in handling nonstationary excitation signals and proves particularly advantageous for calibrating tunable antenna systems. …


Controller Area Network With Flexible Data Rate (Can Fd) Eye Diagram Prediction, Junyong Park, Manho Lee, Shinyoung Park, Jonghoon Kim, Joungho Kim, Donghyun Kim Jan 2024

Controller Area Network With Flexible Data Rate (Can Fd) Eye Diagram Prediction, Junyong Park, Manho Lee, Shinyoung Park, Jonghoon Kim, Joungho Kim, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

A method for predicting the eye diagram for a controller area network with a flexible data rate (CAN FD) is proposed in this article. A CAN FD changes a data rate according to the status to overcome the limitation of latency. In other words, when data to be transmitted are accumulated, the CAN FD increases the data rate up to 5 Mb/s. The CAN FD has a bus topology consisting of multiple electronic control units, which results in a significant amount of signal reflection. Thus, the above causes the signal integrity analysis uncertain. To avoid this, this article proposes a …


Improved Peec Modeling Of Antennas Through Time-Dependent Partial Elements, Fabrizio Loreto, Giuseppe Pettanice, Martin Stumpf, Albert E. Ruehli, Jonas Ekman, Giulio Antonini Jan 2024

Improved Peec Modeling Of Antennas Through Time-Dependent Partial Elements, Fabrizio Loreto, Giuseppe Pettanice, Martin Stumpf, Albert E. Ruehli, Jonas Ekman, Giulio Antonini

Electrical and Computer Engineering Faculty Research & Creative Works

Over the Last Twenty Years, the Evolution of Communications Has Extended the Systems' Operating Frequency Range to the Tens of GHz. in This Framework, Time Domain Integral Equation-Based (TDIE) Methods for Antenna Modeling Have Gained Increasing Interest. among Them, the Partial Elements Equivalent Circuit (PEEC) Method Turns Out to Be Attractive for its Capability to Provide Compact Circuit Models. Similarly to Other Integral Equation-Based Methods, Like the Method of Moments (MoM) in the Time Domain (TD), the PEEC Method Can Suffer from Late-Time Instabilities. This Work Shows that a Rigorous Computation of the Time-Dependent Partial Elements Leads to an Improved …


Adaptive Critic Optimal Control Of An Uncertain Robot Manipulator With Applications, Ravi Prakash, Laxmidhar Behera, Sarangapani Jagannathan Jan 2024

Adaptive Critic Optimal Control Of An Uncertain Robot Manipulator With Applications, Ravi Prakash, Laxmidhar Behera, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Realistic manipulation tasks involve a prolonged sequence of motor skills in varying control environments consisting of uncertain robot dynamic models and end-effector payloads. To address these challenges, this article proposes an adaptive critic (AC)-based basis function neural network (BFNN) optimal controller. Using a single neural network (NN) with a basis function, the proposed optimal controller simultaneously learns task-related optimal cost function, robot internal dynamics, and optimal control law. This is achieved through the development of a novel BFNN tuning law using closed-loop system stability. Therefore, the proposed optimal controller provides real-time, implementable, cost-effective control solutions for practical robotic tasks. The …


Evaluation Of Transfer Learning Models On Traumatic Brain Injury Severity Classification, Ngoc Do, Daniel B. Hier, Tayo Obafemi-Ajayi Jan 2024

Evaluation Of Transfer Learning Models On Traumatic Brain Injury Severity Classification, Ngoc Do, Daniel B. Hier, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

After traumatic brain injury (TBI), clinicians use the Glasgow Coma Scale (GCS) to classify patients by severity and radiologists use the Rotterdam score and the Marshall score to classify CT scans by severity. This work investigates a viable efficient low-cost transfer learning model to use MRI images to predict GCS, Rotterdam, and Marshall severity class after TBI. The enhanced transfer learning model architecture integrates multiple fine-tuning steps in which a few layers of the pre-trained model is unfrozen in each iteration so that the neural network is able to learn layer by layer further aspects of the image for better …


Mechanisms For Unwanted Magnetic Field Coupling To A Shielded Magnetic Near-Field Probe, Xin Yan, Wei Zhang, Sajjad Sadeghi, Mehdi Gholizadeh, David J. Pommerenke, Daryl G. Beetner Jan 2024

Mechanisms For Unwanted Magnetic Field Coupling To A Shielded Magnetic Near-Field Probe, Xin Yan, Wei Zhang, Sajjad Sadeghi, Mehdi Gholizadeh, David J. Pommerenke, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

Unwanted field coupling is a major concern when using magnetic near-field probes for high-frequency scanning. The unwanted coupling of the tangential electric field to a tangential magnetic field probe has been studied extensively. This article shows a second unwanted coupling mechanism: coupling from a vertical magnetic field. The standing wave of a shorted pure TEM microstrip in air is utilized to separate the magnetic and electric field coupling. Simulations show that the eddy currents induced within the probe by the vertical magnetic field couple inductively to the pickup loop if the layer stack up is not symmetric. The unwanted magnetic …


Virtual Inertia Scheduling (Vis) For Microgrids With Static And Dynamic Security Constraints, Buxin She, Fangxing Li, Jinning Wang, Hantao Cui, Xiaofei Wang, Rui Bo Jan 2024

Virtual Inertia Scheduling (Vis) For Microgrids With Static And Dynamic Security Constraints, Buxin She, Fangxing Li, Jinning Wang, Hantao Cui, Xiaofei Wang, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

Microgrids feature a high penetration of inverter-interfaced distributed energy resources (DERs). The low inertia characteristic and fast dynamics of DERs pose challenges to conventional decoupled static economic operation and dynamic control design within microgrids. Hence, this paper proposed virtual inertia scheduling (VIS) for microgrids, aiming to ensure both economy and security. First, a unified framework for device-level control and grid-level operation is introduced, with VIS serving as a key application to address low inertia issues. VIS actively harnesses the controllability and flexibility of DERs to effectively manage microgrid inertia. It updates the conventional economic operation framework by incorporating the virtual …


Cascading Of 2d And 3d Simulations Of Asic Substrate Interconnect Up To 100 Ghz, Zhekun Peng, Junyong Park, Sathvika Bandi, Santosh Pappu, Srinivas Venkataraman, Xu Wang, Granthana Ranzaswamy, Donghyun Kim Jan 2024

Cascading Of 2d And 3d Simulations Of Asic Substrate Interconnect Up To 100 Ghz, Zhekun Peng, Junyong Park, Sathvika Bandi, Santosh Pappu, Srinivas Venkataraman, Xu Wang, Granthana Ranzaswamy, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

A method of cascading 3D models and 2D models to model the full channel of ASIC package substrate interconnects is proposed, showing good match to full-wave results in S-parameter and TDR up to 100 GHz.


Rapid Control Prototyping Platform For Grid Connected Electrical Energy Conversion Systems, Shruti Pandey, Noah Damron, Michael Mcintyre Jan 2024

Rapid Control Prototyping Platform For Grid Connected Electrical Energy Conversion Systems, Shruti Pandey, Noah Damron, Michael Mcintyre

Electrical and Computer Engineering Faculty Research & Creative Works

Electrical Energy Conversion Systems (EECSs) are extensively utilized in contemporary stand-alone systems to supply power to isolated loads. They are also integrated into distributed generation systems, micro grids, and smart grids. In each of these contexts, it is essential to conduct efficient energy management procedures to optimize the electrical energy systems output and ensure the effective and high-quality delivery of electric energy to consumers. To create the energy management system for such a system, careful consideration must be given to the configuration of the power conversion and conditioning system, as well as the specific hardware devices that make up this …


Sensor Tasking Strategies For Space-Based Observers In The Cislunar Environment, Smriti Nandan Paul, Roshan Thomas Eapen, Puneet Singla Jan 2024

Sensor Tasking Strategies For Space-Based Observers In The Cislunar Environment, Smriti Nandan Paul, Roshan Thomas Eapen, Puneet Singla

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The cislunar space environment has witnessed an increase in activities, and future projections indicate significant growth in object population. Consequently, it becomes crucial to monitor these objects for space domain awareness (SDA) purposes. As the number of objects surpasses the available observers, meticulous sensor tasking becomes essential. This paper focuses on designing and exploring strategies for observing and keeping custody of known objects in cislunar space. Optical space-based telescopes, combined with lunar ground-based telescope, are employed for sensor tasking of cislunar objects residing in valuable orbits. The proposed research aims to address the following key points: (1) examination of the …


Cf/Sic Ceramic Matrix Composites With Extraordinary Thermomechanical Properties Up To 2000 °C, Min Sung Park, Jian Gu, Heesoo Lee, Sea Hoon Lee, Lun Feng, William Fahrenholtz Jan 2024

Cf/Sic Ceramic Matrix Composites With Extraordinary Thermomechanical Properties Up To 2000 °C, Min Sung Park, Jian Gu, Heesoo Lee, Sea Hoon Lee, Lun Feng, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The thermomechanical properties of carbon fiber reinforced silicon carbide ceramic matrix composites (Cf/SiC CMCs) were studied up to 2000 °C using high temperature in situ flexural testing in argon. The CMC specimens were fabricated using an ultrahigh concentration (66 vol%) aqueous slurry containing nano-sized silicon carbide powder. The SiC powder compacts were obtained by drying the slurry and were densified using the precursor impregnation and pyrolysis (PIP) method with field assisted sintering technology/spark plasma sintering (FAST/SPS). The high relative density of the SiC green body (77.6%) enabled densification within 2.5 days using four PIP cycles. In contrast, conventional PIP processes …


Bipolar Hipims Kick-Pulse For High Hardness In High-Entropy Boride Thin Films, Nathaniel S. Mcilwaine, Nestor O.Marquez Rios, Eva Zurek, Donald W. Brenner, William G. Fahrenholtz, Stefano Curtarolo, Douglas E. Wolfe, Jon Paul Maria Jan 2024

Bipolar Hipims Kick-Pulse For High Hardness In High-Entropy Boride Thin Films, Nathaniel S. Mcilwaine, Nestor O.Marquez Rios, Eva Zurek, Donald W. Brenner, William G. Fahrenholtz, Stefano Curtarolo, Douglas E. Wolfe, Jon Paul Maria

Materials Science and Engineering Faculty Research & Creative Works

We report a microhardness indentation study for multicomponent refractory metal boride thin films that belong to the family of high-entropy ceramics exhibiting superior hardness and high temperature properties. We focus on the nominally equimolar composition (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2) B2, which we refer to as HEB3, on c-plane sapphire substrates. Thin films are prepared using bipolar high power impulse magnetron sputtering (HiPIMS), where the positive kick pulse is optimized to produce films with high density, high crystallinity, and a microstructure that is isometric in nature as revealed by cross-sectional fracture surface imaging, X-ray diffraction, and X-ray reflectometry. Low-load Knoop indentation is used to …


Individual Differences In Music-Evoked Autobiographical Memories, Kelly Jakubowski, Edith Lee, Elena Bai, Amy M. Belfi Jan 2024

Individual Differences In Music-Evoked Autobiographical Memories, Kelly Jakubowski, Edith Lee, Elena Bai, Amy M. Belfi

Psychological Science Faculty Research & Creative Works

Music is increasingly used as a cue for autobiographical memories in psychological research and clinical interventions. Despite the burgeoning body of evidence on the phenomenology of music-evoked autobiographical memories (MEAMs), few previous studies have focused in detail on how the capacities and experiences of individual listeners impact features of MEAMs. The present work examined the relationship of individual differences in visual and auditory imagery, musical familiarity and engagement, musical reward sensitivity, musical training, and gender to MEAM features. Participants (N = 304, ages 18–25 years, 156 female) completed a self-selected MEAM task, in which they described an autobiographical memory they …


Musical Reward In Young Children, Haley E. Kragness, Kendra Mehl, Amy M. Belfi Jan 2024

Musical Reward In Young Children, Haley E. Kragness, Kendra Mehl, Amy M. Belfi

Psychological Science Faculty Research & Creative Works

Musical pleasure stems from an interplay of social, emotional, and cognitive factors. In adults, there are large individual differences in musical reward, with some individuals (deemed "hyperhedonic" to music) reporting very high reward and others (deemed "anhedonic" to music) reporting very low reward. Musical anhedonia is, therefore, a selective lack of pleasure in response to music, defined by self-reported low musical reward in the absence of generalized anhedonia. While this phenomenon has been investigated in adults in recent years, little is known about musical anhedonia or musical reward more generally in children. To address this, we investigated parents' perceptions of …


Oxygen Fugacity Of Global Ocean Island Basalts, Lori N. Willhite, Ricardo Arevalo, Philip Piccoli, John C. Lassiter, Devin Rand, Matthew G. Jackson, James M.D. Day, Robert W. Nicklas, Marek Locmelis, Thomas J. Ireland, Igor S. Puchtel Jan 2024

Oxygen Fugacity Of Global Ocean Island Basalts, Lori N. Willhite, Ricardo Arevalo, Philip Piccoli, John C. Lassiter, Devin Rand, Matthew G. Jackson, James M.D. Day, Robert W. Nicklas, Marek Locmelis, Thomas J. Ireland, Igor S. Puchtel

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Mantle plumes contain heterogenous chemical components and sample variable depths of the mantle, enabling glimpses into the compositional structure of Earth's interior. In this study, we evaluated ocean island basalts (OIB) from nine plume locations to provide a global and systematic assessment of the relationship between fO2 and He-Sr-Nd-Pb-W-Os isotopic compositions. Ocean island basalts from the Pacific (Austral Islands, Hawaii, Mangaia, Samoa, Pitcairn), Atlantic (Azores, Canary Islands, St. Helena), and Indian Oceans (La Réunion) reveal that fO2 in OIB is heterogeneous both within and among hotspots. Taken together with previous studies, global OIB have elevated and heterogenous fO …


Project Wars: A Serious Game To Teach Decision Making In Project Execution, Cecil Eng Huang Chua, Veda C. Storey, Linda Wallace Jan 2024

Project Wars: A Serious Game To Teach Decision Making In Project Execution, Cecil Eng Huang Chua, Veda C. Storey, Linda Wallace

Business and Information Technology Faculty Research & Creative Works

Project execution (i.e., the production, delivery, and deployment of an information system project's outputs) is a difficult concept to teach effectively because of the many real-time decision-making variables facing a project manager. This paper introduces Project Wars, a web-based serious game designed to teach the project execution concepts of deferral of gratification, organizational mindfulness, and discipline in the face of adversity. Project Wars serves as both a platform to instill these concepts and as a basis for discussions on other critical concepts. The latter includes project team management and control, project leadership, the relationship between productivity, slack, and overtime, and …


Solar Enhanced Oxygen Evolution Reaction With Transition Metal Telluride, Harish Singh, Taishi Higuchi-Roos, Fabrice Roncoroni, David Prendergast, Manashi Nath Jan 2024

Solar Enhanced Oxygen Evolution Reaction With Transition Metal Telluride, Harish Singh, Taishi Higuchi-Roos, Fabrice Roncoroni, David Prendergast, Manashi Nath

Chemistry Faculty Research & Creative Works

The Photo-Enhanced Electrocatalytic Method of Oxygen Evolution Reaction (OER) Shows Promise for Enhancing the Effectiveness of Clear Energy Generation through Water Splitting by using Renewable and Sustainable Source of Energy. However, Despite Benefits of Photo electrocatalytic (PEC) Water Splitting, its Uses Are Constrained by its Low Efficiency as a Result of Charge Carrier Recombination, a Large overpotential, and Sluggish Reaction Kinetics. Here, We Illustrate that Nickel Telluride (NiTe) Synthesized by Hydrothermal Methods Can Function as an Extremely Effective Photo-Coupled Electrochemical Oxygen Evolution Reaction (POER) Catalyst. in This Study, NiTe Was Synthesized by Hydrothermal Method at 145°C within Just an Hour …


Early Detection Of Driving Maneuvers For Proactive Congestion Prevention, Debasree Das, Shameek Bhattacharjee, Sandip Chakraborty, Bivas Mitra, Sajal K. Das Jan 2024

Early Detection Of Driving Maneuvers For Proactive Congestion Prevention, Debasree Das, Shameek Bhattacharjee, Sandip Chakraborty, Bivas Mitra, Sajal K. Das

Computer Science Faculty Research & Creative Works

Road Traffic Congestion Affects Not Only the Commute Delay but Also a city's overall Social, Economic, and Environmental Growth. Existing Approaches for Road Congestion Mitigation Primarily Adopt a Reactive Approach by Detecting Congestion after It Occurs and Recommending Alternate Routes to the Vehicles, Which Fails to Prevent Congestion Cascading. in Contrast, We Propose a Pervasive Platform Called ProCon that Proactively Infers the Driving Micro-Behaviors that Can Contribute to Congestion Formation and Assist the Drivers in Avoiding Such Maneuvers in Real-Time during the Navigation. Thorough Evaluations over Multiple Real-Life and Simulated Datasets Indicate that ProCon Can Reduce Congestion for More Than …


An Ai-Based Conceptual Framework To Improve Program Management Of Complex Systems, Michael D. Parrish, Steven Corns Jan 2024

An Ai-Based Conceptual Framework To Improve Program Management Of Complex Systems, Michael D. Parrish, Steven Corns

Engineering Management and Systems Engineering Faculty Research & Creative Works

With evolving technologies, changing requirements, and limited budgets, governments and industries need to consider new methodologies to help streamline program lifecycle management, from cradle to grave, to ensure projects are delivered on time, on budget, and to the expected performance standards. Traditional approaches fail to adequately address the added complexities of System of Systems programs such as integration, interoperability, and variable lifecycle of subcomponents. The objective of this study is to assess and address the research question - can a new acquisition approach be designed to address and improve program lifecycle management of complex systems? A comparison study, using the …


High Temperature Oxidation Regime Transitions In Hafnium Carbide, Jonathan A. Scott, Xiaoqing He, David W. Lipke Jan 2024

High Temperature Oxidation Regime Transitions In Hafnium Carbide, Jonathan A. Scott, Xiaoqing He, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Understanding the oxidation behavior of hafnium carbide is crucial to its application in extreme environments. In this work, the transition in high-temperature oxidation kinetics regimes in hafnium carbide is explained based on phase equilibria considerations supported by observed changes in oxide scale microstructure evolution associated with different transformation pathways. Below, a composition-dependent critical temperature and oxygen pressure, hafnium carbide first transforms to an amorphous material with nominal composition HfO2C followed by phase separation into carbon and hafnia domains. Subsequently, gaseous transport through a nanometric pore network formed by oxidative removal of phase-separated carbon becomes rate-limiting. Above this critical point, the …


Multiple Imputation For Robust Cluster Analysis To Address Missingness In Medical Data, Arnold Harder, Gayla R. Olbricht, Godwin Ekuma, Daniel B. Hier, Tayo Obafemi-Ajayi Jan 2024

Multiple Imputation For Robust Cluster Analysis To Address Missingness In Medical Data, Arnold Harder, Gayla R. Olbricht, Godwin Ekuma, Daniel B. Hier, Tayo Obafemi-Ajayi

Mathematics and Statistics Faculty Research & Creative Works

Cluster Analysis Has Been Applied To A Wide Range Of Problems As An Exploratory Tool To Enhance Knowledge Discovery. Clustering Aids Disease Subtyping, I.e. Identifying Homogeneous Patient Subgroups, In Medical Data. Missing Data Is A Common Problem In Medical Research And Could Bias Clustering Results If Not Properly Handled. Yet, Multiple Imputation Has Been Under-Utilized To Address Missingness, When Clustering Medical Data. Its Limited Integration In Clustering Of Medical Data, Despite The Known Advantages And Benefits Of Multiple Imputation, Could Be Attributed To Many Factors. This Includes Methodological Complexity, Difficulties In Pooling Results To Obtain A Consensus Clustering, Uncertainty Regarding …


Revisiting The Divergent Multipole Expansion Of Atom-Surface Interactions: Hydrogen And Positronium, Α -Quartz, And Physisorption, Ulrich D. Jentschura Jan 2024

Revisiting The Divergent Multipole Expansion Of Atom-Surface Interactions: Hydrogen And Positronium, Α -Quartz, And Physisorption, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

We revisit the derivation of multipole contributions to the atom-wall interaction previously presented in Łach et al. [G. Łach, M. DeKieviet, and U. D. Jentschura, Phys. Rev. A 81, 052507 (2010)10.1103/PhysRevA.81.052507]. A careful reconsideration of the angular momentum decomposition of the second-, third-, and fourth-rank tensors composed of the derivatives of the electric-field modes leads to a modification for the results for the quadrupole, octupole, and hexadecupole contributions to the atom-wall interaction. Asymptotic results are given for the asymptotic long-range forms of the multipole terms, in both the short-range and long-range limits. Calculations are carried out for hydrogen and positronium …


Lidar From The Sky: Uav Integration And Fusion Techniques For Advanced Traffic Monitoring, Baya Cherif, Hakim Ghazzai, Ahmad Alsharoa Jan 2024

Lidar From The Sky: Uav Integration And Fusion Techniques For Advanced Traffic Monitoring, Baya Cherif, Hakim Ghazzai, Ahmad Alsharoa

Electrical and Computer Engineering Faculty Research & Creative Works

Light detection and ranging (LiDAR) technology's expansion within the autonomous vehicles industry has rapidly motivated its application in numerous growing areas, such as smart cities, agriculture, and renewable energy. In this article, we propose an innovative approach for enhancing aerial traffic monitoring solutions through the application of LiDAR technology. The objective is to achieve precise and real-time object detection and tracking from aerial perspectives by integrating unmanned aerial vehicles with LiDAR sensors, thereby creating a potent Aerial LiDAR (A-LiD) solution for traffic monitoring. First, we develop a novel deep learning algorithm based on pointvoxel-region-based convolutional neural network (RCNN) to conduct …


Design Of Experiment Analysis On Multiple Pim Sources In An Rf Antenna System, Shengxuan Xia, Yuchu He, Haicheng Zhou, Hanfeng Wang, Chulsoon Hwang Jan 2024

Design Of Experiment Analysis On Multiple Pim Sources In An Rf Antenna System, Shengxuan Xia, Yuchu He, Haicheng Zhou, Hanfeng Wang, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Passive intermodulation (PIM) has been identified as one of the common root causes for receiving sensitivity degradation (desense) on radiofrequency (RF) antennas working in frequency-division duplex mode. The component-level PIM characterization and simulation have been well-established over the years. However, the study has been using an ideal 50 Ω transmission line system while antenna modules are more complicated than a simple transmission line structure. Moreover, the metallic contacts can exist in multiple locations with different connection topologies in real applications. This paper provides a method to simulate the PIM performance caused by the metallic contacts in a practical environment. In …