Engineering Commons^™

Development Of An Analytical Model For Beams With Two Dimples In Opposing Directions, Mofareh H. Ghazwani

Masters Theses

Structures such as beams and steel plates can produce potentially high levels of unwanted vibrations and noises in the environment. A method of improving the vibration and acoustic characteristics of beams based on introducing dimples on its surfaces will be presented in this study. This method focuses on creating two dimples in the same and opposite direction on beam’s surface where the effect of dimples on the change in beam’s natural frequencies is the problems of interest.

A boundary value model (BVM) is developed for a beam with two dimples and subjected to various boundary conditions using Hamilton’s Variational Principle. …

Model Based Vehicle Simulation For Electrically Actuated Transmission Test Cells, Kenneth L. Gruel

Masters Theses

The Eaton Vehicle Group is responsible for the development of a large family of automotive products, including manual and automated manual transmissions for light, medium, and heavy duty vehicles. To further expand the transmission testing capabilities at Vehicle Group headquarters, the Vehicle Simulator system was developed and integrated into an existing motor-based test cell. System development time and cost were reduced by leveraging readily available vehicle models and real-time hardware. The Vehicle Simulator system allows a user to control the speed and torque settings of the test cell motors in manual mode, or switch the motors to vehicle emulation mode. …

Design And Evaluation Of An L-Band Current-Mode Class-D Power Amplifier Integrated Circuit, Michael J. Shusta

Masters Theses

Power amplifiers (PAs) convert energy from DC to high frequencies in all radio and microwave transmitter systems be they wireless base stations, handsets, radars, heaters, and so on. PAs are the dominant consumers of energy in these systems and, therefore, the dominant sources of system cost and inefficiency. Research has focused on efficient solid-state PA circuit topologies and their optimization since the 1960s. The 2000s saw the current-mode class-D (CMCD) topology, potentially suitable for today's wireless communications systems, show promise in the UHF frequency band. This thesis describes the design and testing of a high-efficiency CMCD amplifier with an integrated …

Development Of Safety Performance Functions For Non-Motorized Traffic Safety, Hamidreza Ahady Dolatsara

Masters Theses

This study investigates the factors which affect the safety of non-motorized transportation within the influence area of intersections to enhance development of safety performance functions (SPFs). The scope of this study is limited to the four Michigan cities of Ann Arbor, East Lansing, Flint and Grand Rapids. Due to the current lack of research regarding the appropriate size of the influence area, this study investigates the distance of crashes relative to the center of 148 intersections to identify the most probable area of influence for different crash types. For motorized and non-motorized crashes, 240 ft. and 137 ft. are proposed, …

A Framework To Predict High Risk Roadways For Pedestrians In Tennessee, Zane Hunter Pannell

Masters Theses

Pedestrians and bicyclists are a class of vulnerable road users that are often over-represented in incapacitating injury or fatal crash statistics. Because non-motorized trips are vital to many urban and rural residents for utility or recreation and exercise, it is essential to identify safety deficiencies in our existing transportation infrastructure to address rising injuries and fatalities among this group of road users. As the economy continues to struggle and fuel prices remain high, many cities and rural transportation agencies are seeing large increases in bicycling, walking, and transit ridership. While passenger car fatalities have shown sharp declines in the last …

The Effects Of Varying Physical Parameterizations And Initial Conditions On Tracer Transport In The National Aeronautics And Space Administration’S Goddard Earth Observation System Model, Version 5, Melissa Ree Allen

Masters Theses

The evolution of General Circulation Models (GCM) for climate study has led to more accurate predictions for atmospheric transport, yet precision in predictions remains in need of improvement. The National Aeronautics and Space Administration Goddard Earth Observation System model, Version 5 (GEOS-5) represents a state of the art climate model capable of simulating a wide variety of atmospheric processes informed continuously by satellite observations. This thesis examines some of the physical parameterizations employed by GEOS-5 and their effect on the transport of two greenhouse gasses: ozone and carbon dioxide.