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Organizational culture is a product of both internal and external factors. Leaders sometimes attempt to change culture using a variety of mechanisms, while the effects of external environment simultaneously exert influence. The external environment effects can be especially pronounced when comparing a traditional, Midwestern automotive firm (General Motors) with a Silicon Valley automotive startup (Tesla). A study was conducted to compare the social system of these two automakers and to identify some of the factors, both internal and external, shaping their culture. Data was collected on the employment history of engineers and managers using the social networking platform LinkedIn.com. Similarly, publicly-posted employee reviews were collected from the website Glassdoor.com and analyzed using a novel method for classifying and analyzing openorm written survey responses. Together, these records paint a picture of the employee perceptions of culture for both companies, the breadth of external experience represented in their workforces, and the tendency to fill management positions from internal candidates. The results suggest that external environment has broad effects on workforce experience, thereby creating certain cultural attributes such as loyalty or a drive to innovate. The results also suggest that promoting internal candidates more often does not necessarily lead to employee perception of better career opportunities. Taken together, the results reinforce but expand traditional views of organizational culture and call for further study on the matter across more industry groups.

No description available.

No description available.

No description available.

This report describes the speed characteristic and various methods of speed control of DC shunt (separately excited) motors, especially for application in electrical vehicles. The basic behavior of the DC motor is discussed, along with traditional and modern techniques of speed control. As an example, a speed controller for a shunt motor (built and tested by the author) is discussed. Two types of speed controllers for electric cars are discussed, and the performance results for an experimental electric car are presented. Finally, a design for a 24 HP car motor controller using both armature and field control was simulated on a smaller scale in the laboratory.

The source-to-wheel efficiency of today's electrified vehicles already far surpasses the efficiency of strictly gasoline vehicles. As sources of electricity become cleaner and more efficient, and as gasoline becomes more scarce, the need for transporation electrification is increasingly economically and environmentally driven. The automotive industry primarily makes use of permanent magnet synchronous machines (PMSMs) and induction machines (IMs), the latter has the cost advantage of containing no rare earth metals. This thesis studies two different induction motors for electrified powertrain applications using a novel optimization algorithm to create efficiency maps and compare the efficiencies of the two motors. Induction motors are difficult to banchmark due to their complicated control schemes. Each point in their operating range can be achieved with an infinite number of current/slip combinations and therefore has infinite potential efficiencies. The proposed algorithm limits the number of simulations needed to benchmark an induction machine, and provides a clear and unbiased way to compare machines based on losses at their most efficient current/slip combinations over their entire operating range. The proposed algorithm is able to calculate losses within 5% error of simulation values for both machines. The first motor studied makes use of stranded windings and geometry parameters from the Tesla Motors patents. The efficiency map created has a peak efficiency of 96% and corresponds closely to an efficiency map for a similar motor found in literature. The second motor makes use of copper bar windings, which are easier to manufacture and have lower material costs. Bar windings, typically have lower resistance and stator copper losses at low speeds, but higher effective resistance and stator losses at high speeds due to eddy effects. The motor modelled was intended simply to compare the stranded and bar windings, and to see the advantages and disadvantages. For this reason, no other changes are made to the winding layout or motor geometry, including changes that would reduce the eddy effect. The resultant efficiency map has a peak efficiency of only 90%, performing worse than the stranded wound motor across most of its operating range. At very low speeds, under 1000 rpm, the efficiency of the bar wound machine is better than that of the stranded machine. The bar wound machine also has the advantage of being over 80\% efficient everywhere. The author suggests that future research focus on applying the proposed benchmarking algorithm to stator bar motors designed to limit eddy effects. Strategies include changing the slot opening shape, increasing the number of stator bars, and moving the stator bars away from the air gap. / Thesis / Master of Applied Science (MASc)

A long hollow cylinder with five layers, subjected to a random thermal environment is analyzed. The random thermal environment includes the ambient air temperature, solar radiation and wind speed. The location of interest is Phoenix, Arizona. The governing differential equation is the so-called one-dimensional Fourier heat conduction equation in cylindrical coordinates. An implicit finite difference scheme is developed to obtain temperature responses inside the cylinder. Given the linear elastic behavior of materials involved, induced stresses and strains are evaluated at the end of each time step of the finite difference scheme. A statistical analysis is then carried out to determine the probability of failure of the propellant and hence the service life of the motor can be computed. / Ph. D.

The theory of soft variable structure control, which produces robustness to parameter variation and fast transient response, is discussed in this thesis. The digital implementation techniques are presented in the aspects of sample rate, prefilter design, hardware selection, and microprocessor arithmetic operation. Simulation and experimental results showed good performance in negative speed range, but this controller created unwanted high armature current fluctuation in positive speed range. The reasons turned out to be the limitation of sample rate, noise from the tachometer, and high gain at positive speed. / Master of Science / incomplete_metadata

In review, the author is struck with a feeling of the relative insignificance of his findings. Other sources of information seem to have a wealth of ideas, a scope far beyond the present investigation, and a variety of means to approach the subject. Upon further consideration, however, and a realization of the comparative expenditures of time, energy, and thought given to the subject, much familiarity has been gained with the general problem, with the factors involved, and their relative importance. Some interesting experiments have been watched, and the groundwork has been laid for more. In this light, the original purpose has been accomplished. / Master of Science