Master of Science, The Ohio State University, 2007, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science (M.S.), University of Dayton, 2024, Aerospace Engineering

This research introduces an Origami-inspired dynamic spacecraft radiator, capable of adjusting heat rejection in response to orbital variations and extreme temperature fluctuations in lunar environments. The research centers around the square twist origami tessellation, an adaptable geometric structure with significant potential for revolutionizing radiative heat control in space. The investigative involves simulations of square twist origami tessellation panels using vector math and algebra. This study examines both a two-dimensional (2- D), infinitely thin tessellation, and a three-dimensional (3-D), rigidly-foldable tessellation, each characterized by an adjustable closure or actuation angle “φ”. Meticulously analyzed the heat loss characteristics of both the 2D and 3D radiators over a 180-degree range of actuation. Utilizing Monte Carlo Ray Tracing and the concept of “view factors”, the study quantifies radiative heat loss, exploring the interplay of emitted, interrupted, and escaped rays as the geometry adapts to various positions. This method allowed for an in-depth understanding of the changing radiative heat loss behavior as the tessellation actuates from fully closed to fully deployed. The findings reveal a significant divergence between the 2D and 3D square twist origami radiators. With an emissivity of 1, the 3D model demonstrated a slower decrease in the ratio of escaped to emitted rays (Ψ) as the closure/actuation angle increased, while the 2D model exhibited a more linear decline. This divergence underscores the superior radiative heat loss control capabilities of the 2D square twist origami geometry, offering a promising turndown ratio of 4.42, validating the model's efficiency and practicality for radiative heat loss control. Further exploration involved both non-rigidly and rigidly foldable radiator models. The non-rigidly foldable geometry, initially a theoretical concept, is realized through 3D modeling and physica (open full item for complete abstract)

Committee: Rydge Mulford (Advisor) Subjects: Acoustics; Aerospace Engineering; Aerospace Materials; Alternative Energy; Aquatic Sciences; Artificial Intelligence; Astronomy; Astrophysics; Atmosphere; Atmospheric Sciences; Automotive Engineering; Automotive Materials; Biomechanics; Biophysics; Cinematography; Civil Engineering; Communication; Computer Engineering; Design; Earth; Educational Software; Educational Technology; Educational Tests and Measurements; Educational Theory; Electrical Engineering; Engineering; Environmental Engineering; Environmental Science; Experiments; Fluid Dynamics; Geophysics; Geotechnology; High Temperature Physics; Industrial Engineering; Information Systems; Information Technology; Instructional Design; Marine Geology; Materials Science; Mathematics; Mathematics Education; Mechanical Engineering; Mechanics; Mineralogy; Mining Engineering; Naval Engineering; Nuclear Engineering; Nuclear Physics; Ocean Engineering; Petroleum Engineering; Quantum Physics; Radiation; Radiology; Range Management; Remote Sensing; Robotics; Solid State Physics; Sustainability; Systems Design; Theoretical Physics

Doctor of Philosophy (Ph.D.), University of Dayton, 2021, Electrical Engineering

Space-Time Adaptive Processing (STAP) is a modern radar signal processing technique that leverages additional Degrees of Freedom (DoF) to cancel clutter from a background environment and produce detections of slow-moving targets. STAP is well-documented and understood; however, bistatic applications, or applications in which a radar transmitter and receiver are physically separated, present additional complications. This work explores techniques in Bistatic Space-Time Adaptive Processing (B-STAP) for Ground-Moving Target Indication (GMTI)---the detection of slow-moving surface targets through ground clutter. Due to the complexity and availability of B-STAP data, the evaluation of bistatic algorithms is challenging. A simulation framework has been created to test and evaluate monostatic and bistatic STAP algorithms, mitigating the lack of representative test data. The framework leverages foundational techniques and characteristics to provide a flexible and extensible mechanism for testing and evaluation. Additionally, the design of a new pluggable bistatic Expert System (ES) processor is presented. The ES leverages existing data excision and warping techniques and pairs them with new Range-Based Compensation (RBC) and Clutter Scoring methods to optimize covariance estimation. The simulation framework is used to evaluate the effectiveness of the ES compared to a variety of previously established bistatic processing techniques. The results validate the approach taken in the ES and provide a path for future exploration.

Committee: Andrew Bogle PhD (Committee Chair); Robert Penno PhD (Committee Member); Aaron Nielsen PhD (Committee Member); Ethan Lin PhD (Committee Member); Lorenzo Lo Monte PhD (Committee Member) Subjects: Electrical Engineering

Master of Science in Computer Engineering (MSCE), Wright State University, 2019, Computer Engineering

On-going effective control of insect-scale Flapping-Wing Micro Air Vehicles could be significantly advantaged by active in-flight control adaptation. Previous work demonstrated that in simulated vehicles with wing membrane damage, in-flight recovery of effective vehicle attitude and vehicle position control precision via use of an in-flight adaptive learning oscillator was possible. Most recent approaches to this problem employ an island-of-fitness compact genetic algorithm (ICGA) for oscillator learning. The work presented provides the details of a domain specific search space reduction approach implemented with existing ICGA and its effect on the in-flight learning time. Further, it will be demonstrated that the proposed search space reduction methodology is effective in producing an error correcting oscillator configuration rapidly, online, while the vehicle is in normal service.

Committee: John C. Gallagher Ph.D. (Advisor); Michael L. Raymer Ph.D. (Committee Member); Mateen Rizki Ph.D. (Committee Member) Subjects: Computer Engineering

MARCH, University of Cincinnati, 2011, Design, Architecture, Art and Planning: Architecture

The socio-cultural context is rapidly changing, yet much of the resultant architecture has remained unchanged, in process and performance. More mutually enriched relationships between people, the space they inhabit, and the environment may be achieved through an architecture that responds to building occupants and environmental factors. In creative appropriation of technological advances, the space envelope—relative to a more responsive architecture—exceeds its meaning as mere element of enclosure and exclusion. The exterior wall is relieved of its nuanced label as boundary, of the dualistic positions of inside and outside, and moreover, becomes an interface between environments, which lie on both sides. The thesis proposes an architecture that actively differentiates environmental conditions and socio-ecological context through morphological and material articulation. By identifying and relating the behavioral tendencies and performance capacities of material systems with environmental and social inflection the resulting provisions and opportunities for inhabitation approach an architecture that engenders emergent and intensively choice-driven patterns of social formation and occupation. Varied expression and spatiality can provide diverse spatial arrangements together with climatic intensities. The concept proposes a shift from mono-functional modularized building elements, based on linear task-solution concepts, to integral systems with non-linear, complex behavior and properties.

Committee: George Bible MCiv.Eng (Committee Chair); Michael McInturf MARCH (Committee Chair) Subjects: Architecture

MARCH, University of Cincinnati, 2007, Design, Architecture, Art and Planning : Architecture (Master of)

Public spaces within cities – the streets, sidewalks, and squares - act as the grand stage on which urban experiences occur. They provide a place for shared human experiences and spontaneous interactions. However, while there are many successful public spaces around the world, many efforts to design urban plazas and squares have resulted in cold, un-engaging spaces. In these past attempts, the natural existing condition of the city has been ignored, the imperfect and spontaneous characteristics pushed aside in favor of idealistic, almost utopian designs. It can be conjectured that it is these imperfections and inconsistencies that characterize the spaces loved so dearly. This thesis will explore a new way of thinking about urban public spaces, one that embraces the everyday, the dynamic and varied nature of the city, while respecting the history and memory of a given place, specifically through the redesign of Boston's City Hall Plaza.

Committee: Elizabeth Riorden (Advisor) Subjects: Architecture

Master of Science, The Ohio State University, 2010, Electrical and Computer Engineering

This thesis investigates the plausibility of implementing a multiple-input single-output (MISO) synthetic aperture radar (SAR) system for space-time adaptive processing (STAP) with a limited data rate requirement of a single receiver. A MISO-SAR system could provide processing flexibility to radar systems such as the Gotcha radar system developed at the Air Force Research Laboratory. Gotcha is an airborne wide-beam multi-mode radar system used to cover a large area for surveillance. In order to apply multiple algorithms to a large amount of data in real time, the data is downlinked to a supercomputer on the ground. STAP is an adaptive filtering technique, which can be used for improved detection of slow moving targets in the presence of clutter. However, STAP is typically implemented using an array of receiving elements, which significantly increases the data rate for downlinking to the ground. While MISO systems are common in communications applications, it is not a common radar system design approach. The MISO system requires additional waveform design considerations in order to obtain orthogonal transmit waveforms. However, the MISO system provides the additional degrees of freedom needed to apply STAP while maintaining a single receiver data rate.

Committee: Lee Potter PhD (Advisor); Emre Ertin PhD (Committee Member) Subjects: Electrical Engineering