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Full-Text Articles in Engineering
Instructional Case Studies In The Field Of Windfarm Optimization, N. Francesco Baker
Instructional Case Studies In The Field Of Windfarm Optimization, N. Francesco Baker
Theses and Dissertations
Wind farm layout optimization is a multidisciplinary undertaking, requiring students and researchers to integrate many skillsets in order to optimize turbine placement. There is currently a lack of useful benchmarking exercises for participants in the field to compare the efficacy of their methods. This work details the construction and completion of a set of four case studies meant to satisfy this need, with the hope of providing some insight into useful layout optimization approaches. These case studies are intended to also serve as instructive introductory exercises with which newcomers researching wind energy may incrementally practice and increase their abilities.The first …
Bullwhip Effect Of A Closed Leep Supply Chain With And Without Information Sharing Of Customer Demand, Jui-Hsin Hsu
Bullwhip Effect Of A Closed Leep Supply Chain With And Without Information Sharing Of Customer Demand, Jui-Hsin Hsu
Theses and Dissertations
In recent years, companies have become interested in a closed-loop supply chain that is concerned with the recovery pipeline. The expenses of a company can be influenced by large inventories and backlogs due to the bullwhip effect in the supply chain. Previous literature has shown that the bullwhip effect can be decreased by a reverse supply chain. This paper develops a closed-loop supply chain including seven echelons for recovery of end-of-life products. The model considers the order-up-to inventory policy and the exponential smoothing forecasting with a trend method in the system to assist in determining the ordering quantities. The best …
Characterization And Optimization Of An Image Charge Detector For The Measurement Of Martian Dust, Jace Rozsa
Characterization And Optimization Of An Image Charge Detector For The Measurement Of Martian Dust, Jace Rozsa
Theses and Dissertations
Image charge detector (ICD) technology has existed for decades. However, not until recently has an ICD been proposed for use in space exploration, specifically for studying the characteristics of the dust on Mars. Characterizing the dust on Mars is crucial for designing equipment to aid manned missions. It also improves our understanding of Mars' climate and weather systems. An ICD utilizing printed circuit board (PCB) electrodes, coupled with a custom differential amplifier, is best suited for this type of measurement because of its light weight, simplicity, and noise performance. The noise floor of our particular amplifier is measured to be …
Investigation Of Isotruss® Structures In Compression Using Numerical, Dimensional, And Optimization Methods, Hanna Belle Opdahl
Investigation Of Isotruss® Structures In Compression Using Numerical, Dimensional, And Optimization Methods, Hanna Belle Opdahl
Theses and Dissertations
The purpose of this research is to investigate the structural efficiency of 8-node IsoTruss structures subject to uniaxial compression using numerical, dimensional, and optimization methods. The structures analyzed herein are based on graphite/epoxy specimens that were designed for light-weight space applications, and are approximately 10 ft. (3 m) long and 0.3 lb. (0.14 kg). The principal failure modes considered are material failure, global buckling, local buckling at the bay level, and longitudinal strut buckling. Studies were performed with the following objectives: to correlate finite element predictions with experimental and analytical methods; to derive analytical expressions to predict bay-level buckling; to …
Development Of A 3d Computational Vocal Fold Model Optimization Tool, Austin C. Vaterlaus
Development Of A 3d Computational Vocal Fold Model Optimization Tool, Austin C. Vaterlaus
Theses and Dissertations
One of the primary objectives of voice research is to better understand the biomechanics of voice production and how changes in properties of the vocal folds (VFs) affect voice ability and quality. Synthetic VF models provide a way to observe how changes in geometry and material property affect voice biomechanics. This thesis seeks to evaluate an approach of using a genetic algorithm to design synthetic VF models in three ways: first, through the development of a computationally cost-effective 3D vocal fold model; second, by creating and optimizing a variation of this model; and third, by validating the approach. To reduce …
Robust Real-Time Model Predictive Control For High Degree Of Freedom Soft Robots, Phillip Edmond Hyatt
Robust Real-Time Model Predictive Control For High Degree Of Freedom Soft Robots, Phillip Edmond Hyatt
Theses and Dissertations
This dissertation is focused on the modeling and robust model-based control of high degree-of-freedom (DoF) systems. While most of the contributions are applicable to any difficult-to-model system, this dissertation focuses specifically on applications to large-scale soft robots because their many joints and pressures constitute a high-DoF system and their inherit softness makes them difficult to model accurately. First a joint-angle estimation and kinematic calibration method for soft robots is developed which is shown to decrease the pose prediction error at the end of a 1.5 m robot arm by about 85\%. A novel dynamic modelling approach which can be evaluated …
Three-Level Converters For Low Voltage Active Front End Motor Drives, Marzieh Karami
Three-Level Converters For Low Voltage Active Front End Motor Drives, Marzieh Karami
Theses and Dissertations
Electric drives with Active Front End (AFE) converters can provide benefits such as lower harmonic current injections to the grid, smaller size filters, lower THD values and cost saving for injection of power to the grid in brake situations. SiC-MOSFET based two-level converters can be a promising topology for Active Front End (AFE) application in electric drives. The possibility of high switching frequency will make the grid filters smaller. Grid filters are used for EMC and power quality issues. However, there are practical limitations for increasing the switching frequency such as dead time in the gating signals, sampling requirements, and …
Optimization Of Vehicle To Grid System In A Power System With Unit Commitment, Charles Uko
Optimization Of Vehicle To Grid System In A Power System With Unit Commitment, Charles Uko
Theses and Dissertations
This thesis provides a comprehensive overview and analysis of the benefits of using plug-in electric vehicles (PEVs) in solving the unit commitment problem. PEVs are becoming more attractive and a rapid replacement of conventional fuel vehicles due to their environmental-friendly operation. Through collective control by an aggregator, PEVs batteries can also provide ancillary services such as load leveling and frequency regulation to improve the quality of power supplied in the power grid and reduce the cost of power generation. This study presents the modeling, simulation, and analysis of a vehicle-to-grid (V2G) system connected to a smart power grid. The model …
An Analytic Study Of Pursuit Strategies, Mark E. Vlassakis
An Analytic Study Of Pursuit Strategies, Mark E. Vlassakis
Theses and Dissertations
The Two-on-One pursuit-evasion differential game is revisited where the holonomic players have equal speed, and the two pursuers are endowed with a circular capture range ℓ > 0. Then, the case where the pursuers' capture ranges are unequal, ℓ1 > ℓ2 ≥ 0, is analyzed. In both cases, the state space region where capture is guaranteed is delineated and the optimal feedback strategies are synthesized. Next, pure pursuit is considered whereupon the terminal separation between a pursuer and an equal-speed evader less than the pursuer's capture range ℓ > 0. The case with two pursuers employing pure pursuit is considered, and …
Development, Test And Evaluation Of Autonomous Unmanned Aerial Systems In A Simulated Wide Area Search Scenario: An Implementation Of The Autonomous Systems Reference Architecture, Katherine E. Cheney, David D. King
Development, Test And Evaluation Of Autonomous Unmanned Aerial Systems In A Simulated Wide Area Search Scenario: An Implementation Of The Autonomous Systems Reference Architecture, Katherine E. Cheney, David D. King
Theses and Dissertations
The implementation and testing of autonomous and cooperative unmanned systems is challenging due to the inherent design complexity, infinite test spaces, and lack of autonomy specific measures. These challenges are limiting the USAF's ability to deploy and take advantage of tactical and strategic advantages offered by these systems. This research instantiates an Autonomous System Reference Architecture (ASRA) on a Wide Area Search (WAS) scenario as a test bed for rapid prototyping and evaluation of autonomous and cooperative systems. This research aims to pro- vide a framework to evaluate the system’s ability to achieve mission and autonomy objectives, develop reusable autonomous …
Golng Off The Grid: Optimizing Solar Renewable Energy Systems At Remote Locations To Minimize Logistics Requirements, Increase Sustainability, And Strengthen Energy Assurance, Nathanael J. Thomsen
Golng Off The Grid: Optimizing Solar Renewable Energy Systems At Remote Locations To Minimize Logistics Requirements, Increase Sustainability, And Strengthen Energy Assurance, Nathanael J. Thomsen
Theses and Dissertations
Grid-based electrical infrastructure is unavailable at many remote locations including developing nation communities, isolated construction sites, and military contingency bases. Powering these locations with diesel generators requires regular fuel resupply, resulting in increased costs, environmental impacts, and burdensome logistics—making generators an obstacle for energy resiliency and sustainability. This research examines using solar renewable energy systems to replace generators at remote locations and presents a multi-objective optimization model that minimizes logistics variables. Replacing a single deployed generator would save over 500,000 gal of fuel annually, eliminating the need for 100 fuel tanker deliveries.