Engineeringhttp://hdl.handle.net/10342/442024-03-28T23:52:37Z2024-03-28T23:52:37ZIDENTIFYING A RELATIONSHIP BETWEEN DESIGN CONCEPT REPRESENTATION STYLE AND CONSUMER PRODUCT PREFERENCEEcherd, Jon Owenhttp://hdl.handle.net/10342/128882023-06-05T14:08:42Z2023-05-03T00:00:00ZIDENTIFYING A RELATIONSHIP BETWEEN DESIGN CONCEPT REPRESENTATION STYLE AND CONSUMER PRODUCT PREFERENCE
Echerd, Jon Owen
Product designers are constantly seeking insight into the mind of the consumer in efforts to get a better idea as to what the market demands. Feedback from consumers informs designers on changes that need to be made to a product and can provide information about what end-users expect. To explore possible improvements to the design process, a study was conducted on concept representation style and its effects on consumer preferences. The study employed statistical testing to identify a relationship between representation style and consumer preference consistency, lending insight into the best practices for conveying critical information throughout the design process. The study described in this thesis consists of conducting a series of surveys, introducing hand drawings, solid models, and realistic renderings as representations of eyeglass frames to participants, eliciting preference data from those participants, and comparing their preference ratings to those of physical models of the same frames. This study was supplemented with an eye-tracking system to establish a connection of where the effective details lie in the design representations, as well as suggest some decision-making strategies at play. Results indicate that a significant difference in consistency between representation styles does exist, and that CAD solid models are inconsistent with preferences of physical models. When only participants with an engineering background were evaluated however, this relationship did not exist, suggesting that a familiarity with a particular design practice may impact how individuals judge a particular representation style. It is also suggested by eye-tracking analysis that participants were more likely to give semantic responses when observing physical models.
2023-05-03T00:00:00ZGraph Theoretic analysis of the Human Brain Functional Connectivity Alteration Due to Sleep RestrictionAntar, Marwahttp://hdl.handle.net/10342/128522023-06-05T13:54:18Z2023-05-03T00:00:00ZGraph Theoretic analysis of the Human Brain Functional Connectivity Alteration Due to Sleep Restriction
Antar, Marwa
Sleep plays a vital role in learning and memory consolidation. Several studies used brain models of sleep deprivation (SD) and insomnia to study the association between sleep deficiency and cognitive decline conditions. SD was found to cause similar, albeit subtle, cognitive decline symptoms displayed by dementia patients affecting attentional functions, decision making, working and long-term memory. This study examines the effect of sleep restriction (SR) on brain networks and utilizes Functional Connectivity (FC) analysis to identify patterns of information processing between different brain regions. It particularly applies weighted phase-lag index (wPLI) to quantify brain signals synchronization levels during a visual oddball paradigm task that evokes event-related potentials (ERPs) associated with face recognition. This study also examines the viability of graph theoretic analysis (GTA), which provides a holistic view on the brain network topology. GTA quantifies the brain connectivity features to assess the global efficiency and local efficiency of information processing, pre- and post- SR intervention. Significant alterations were found in all graph indices mainly in α-, µ- and β- frequency bands due to induced mental fatigue. The obtained results reveal significantly lower local connections (p < 0.05) and lower global efficiency (p < 0.001), particularly in the α- band as a result of mental fatigue, reflecting the impact of sleep loss on attention and memory processing.
2023-05-03T00:00:00ZSimulating and Optimizing a Zero-Waste Wave-To-Water Desalination SystemGlosson, Gabrielhttp://hdl.handle.net/10342/128432023-06-05T13:52:41Z2023-04-28T00:00:00ZSimulating and Optimizing a Zero-Waste Wave-To-Water Desalination System
Glosson, Gabriel
Current methods of producing clean water are not capable of meeting growing demands. One method of producing clean water is through a process called desalination, which is the process of removing salt and other minerals from seawater. However, traditional desalination methods can be energy-intensive and generate significant amounts of waste. To help address these issues, a hybrid wave-to-water desalination system that combines reverse osmosis (RO) with supercritical water desalination (SCWD) can produce freshwater from seawater. SCWD treats the brine produced by RO, while RO produces freshwater at a lower energy cost. The system utilizes an oscillating surge wave energy converter (OSWEC) to harness the energy of ocean waves to directly pressurize the seawater feeding into the RO system. Using ocean waves as an energy source makes the system renewable and reduces the carbon footprint of the desalination process. This thesis presents the development of a simulation for a small-scale zero-waste desalination system powered by off-grid renewable energy. The model of the system was developed using MATLAB Simulink along with WEC-Sim. A sensitivity analysis was performed on the model to determine the optimal configuration of key system parameters. The sensitivity analysis was conducted using an irregular wave pattern with a significant wave height of 0.117 m and a period of 1.68 s. The parameters investigated in the sensitivity analysis were the system's power take-off (PTO) volumetric displacement, accumulator size, and RO membrane type. The results of the sensitivity analysis showed that the optimized system was the one that used an SW30HR-380 RO membrane, a PTO volumetric displacement of 1975 cm^3/rad, and a 10-gallon accumulator. The average water production rate for the optimized system was 32.644 gpm.
2023-04-28T00:00:00ZOSCILLATING SURGE WAVE ENERGY CONVERTER GEOMETRY OPTIMIZATION FOR DIRECT SEAWATER DESALINATIONMcMorris, Jasonhttp://hdl.handle.net/10342/128362023-06-05T13:47:50Z2023-05-03T00:00:00ZOSCILLATING SURGE WAVE ENERGY CONVERTER GEOMETRY OPTIMIZATION FOR DIRECT SEAWATER DESALINATION
McMorris, Jason
Having a reliable supply of fresh water is a problem that affects nations around the world. Saltwater desalination is one of the best methods for fulfilling this need, but it is an energy-intensive process that is expensive to maintain. Wave energy can be utilized to increase the efficiency of seawater desalination using a wave energy converter (WEC) to lower the external energy requirement. This thesis presents an analysis of scaled down flap-type oscillating surge wave energy converter (OSWEC) geometries and their effects on the power output. The performance of the OSWEC was tested using different flap shapes in addition to different configurations of thickness, density, and center of mass. The tested wave conditions were based on scaled down wave conditions at Jennette's Pier in Nag's Head, North Carolina, and used a significant wave height of 0.117m and a natural period of 1.68s. The system's power take-off (PTO) was also manipulated using different damping and stiffness coefficients to maximize the power generated from the OSWEC. The results of the wave simulations showed that the thinnest configuration of the variable thickness cylindrical flap shape, with the highest tested density and center of mass, produced the most power using the given wave conditions with an average power output of 30.11W.
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