Design Optimization of Nozzle Shapes for Maximum Uniformity of Exit Flow

The objective of this study is to identify the optimal designs of converging-diverging supersonic and hypersonic nozzles that perform at maximum uniformity of thermodynamic and flow-field properties with respect to their average values at the nozzle exit. Since this is a multi-objective design optimization problem, the design variables used are parameters defining the shape of the nozzle. This work presents how variation of such parameters can influence the nozzle exit flow non-uniformities. A Computational Fluid Dynamics (CFD) software package, ANSYS FLUENT, was used to simulate the compressible, viscous gas flow-field in forty nozzle shapes, including the heat transfer analysis. The results of two turbulence models, k-e and k-ω, were computed and compared. With the analysis results obtained, the Response Surface Methodology (RSM) was applied for the purpose of performing a multi-objective optimization. The optimization was performed with ModeFrontier software package using Kriging and Radial Basis Functions (RBF) response surfaces. Final Pareto optimal nozzle shapes were then analyzed with ANSYS FLUENT to confirm the accuracy of the optimization process.

Understanding the Impact of the Property Tax Appeal Process on Assessment Uniformity: Procedures, Structures, and Outcomes

Property taxes serve as a vital revenue source for local governments. The revenues derived from the property tax function as the primary funding source for a variety of critical local public service systems. Property tax appeal systems serve as quasi-administrative-judicial mechanisms intended to assure the public that property tax assessments are correct, fair, and equitable. Despite these important functions, there is a paucity of empirical research related to property tax appeal systems. This study contributes to property tax literature by identifying who participates in the property tax appeal process and examining their motivations for participation. In addition, the study sought to determine whether patterns of use and success in appeal systems affected the distribution of the tax burden. Data were collected by means of a survey distributed to single-family property owners from two Florida counties. In addition, state and county documents were analyzed to determine appeal patterns and examine the impact on assessment uniformity, over a three-year period. The survey data provided contextual evidence that single-family property owners are not as troubled by property taxes as they are by the conduct of local government officials. The analyses of the decision to appeal indicated that more expensive properties and properties excluded from initial uniformity analyses were more likely to be appealed, while properties with homestead exemptions were less likely to be appealed. The value change analyses indicated that appeals are clustered in certain geographical areas; however, these areas do not always experience a greater percentage of the value changes. Interestingly, professional representation did not increase the probability of obtaining a reduction in value. Other relationships between the variables were discovered, but often with weak predictive ability. Findings from the assessment uniformity analyses were also interesting. The results indicated that the appeals mechanisms in both counties improved assessment uniformity. On average, appealed properties exhibited greater horizontal and vertical inequities, as compared to non-appealed properties, prior to the appeals process. After, the appeal process was completed; the indicators of horizontal and vertical equity were largely improved. However, there were some indications of regressivity in the final year of the study.

The effect of the advanced placement examination for credit policy by the Florida State universities on the acceleration of a student's postsecondary education

The purpose of this research study was to determine if the Advanced Placement program as it is recognized by the universities in the Florida State University System (SUS) truly serves as an acceleration mechanism for those students who enter an SUS institution with passing AP scores. Despite mandates which attempt to control uniformity of policy, each public university in Florida determines which courses will be exempted and the number of credits they will grant for passing Advanced Placement courses.^ This is a descriptive study in which the AP policies of each of the SUS institutions were compared. Additionally, the college attendance and graduation data on members of a cohort of 593 Broward County high school graduates of the class of June, 1992 were compared. Approximately 28% of the cohort members entered university with passing Advanced Placement scores.^ The rate of early and on time graduation was significantly dependent on the Advanced Placement standing of the students in the cohort. Given the financial and human cost involved, it is recommended that all state universities bring their Advanced Placement policies into line with each other and implement a uniform Advanced Placement policy. It is also recommended that a follow-up study be conducted with a new cohort bound under the current 120 credit limitation for graduation. ^

A review of Taiwan's technological five-year junior college mechanical engineering curriculum development: 1948 to 1994

Taiwan's technological five-year junior college (TFYJC) was founded in 1948 to train technicians to meet the demand coming from national construction. Site level professionals never were trained in curriculum development as this was under strict national control. The purpose of this study is to present an accurate narrative of Taiwan's TFYJC mechanical engineering curriculum development history in order to display the focus, rationale, and influencing forces of the evolving curriculum. This study employed historical research methodology and used document analysis as the primary approach.^ This analysis revealed that the target FYJC curriculum was manufacturing-oriented. The range of government control shifted from little, to full, then to partial control of the curriculum, from autonomy to uniformity then to partial autonomy. The intention of the target curriculum development was always to advance domestic economic development. Voices from the academia and government also influenced curriculum development decisions. Currently, the government has instituted a shift in focus and content causing individual institutions to develop curriculum responses addressing the challenge of advancing Taiwan's position in a global economy.^ Considering the shift in policy and practice, individual institutions intending to design curriculum are advised to implement empirical needs assessments of students, graduates, and employers and to engage in critical studies of emerging resources in order to provide effective in service training. To accomplish this end, TFYJC faculty and administration need training in curriculum theory and practice and evaluation. ^

The "Beef" about Beef

The grading of beef has become a controversial issue, with both government and the cattle industry working to ensure uniformity. The author contends that meat quality, and the resulting tenderness, juiciness, and flavor desired by consumers, is being threatened by such pressures and actions.

Content Analysis of Outcome Assessment of Global Learning Foundations Courses: A Case Study

This study used content analysis to interpret and evaluate outcome evaluation matrices of undergraduate Global Learning foundations courses. The findings revealed a lack of uniformity in the faculty members’ interpretation and implementation of global learning components in the coursework. Successful teaching practices and challenges were identified and classified.

Modeling instruction: Positive attitudinal shifts in introductory physics measured with CLASS

Among the most surprising findings in Physics Education Research is the lack of positive results on attitudinal measures, such as Colorado Learning Attitudes about Science Survey (CLASS) and Maryland Physics Expectations Survey (MPEX). The uniformity with which physics teaching manages to negatively shift attitudes toward physics learning is striking. Strategies which have been shown to improve conceptual learning, such as interactive engagement and studio-format classes, provide more authentic science experiences for students; yet do not seem to be sufficient to produce positive attitudinal results. Florida International University’s Physics Education Research Group has implemented Modeling Instruction in University Physics classes as part of an overall effort toward building a research and learning community. Modeling Instruction is explicitly designed to engage students in scientific practices that include model building, validation, and revision. Results from a preinstruction/postinstruction CLASS measurement show attitudinal improvements through both semesters of an introductory physics sequence, as well as over the entire two-course sequence. In this Brief Report, we report positive shifts from the CLASS in one section of a modeling-based introductory physics sequence, for both mechanics (N=22) and electricity and magnetism (N=23). Using the CLASS results and follow up interviews, we examine how these results reflect on modeling instruction and the unique student community and population at FIU.

Loaxahatchee Impoundment Landscape Assessment (LILA): Tree Island Experiments and Management; May 1, 2005 to September 4, 2009: Final Report

Hydrologic modifications have negatively impacted the Florida Everglades in numerous significant ways. The compartmentalization of the once continuously flowing system into the Water Conservation Areas (WCAs) caused disruption of the slow natural flow of water south from Lake Okeechobee through the Everglades to Florida Bay. The ponding of water in the WCAs, the linking of water flow to controlled water levels, and the management of water levels for anthropogenic vs. ecological well-being has caused a reduction in the spatial heterogeneity of the Everglades leading to greater uniformity in topography and vegetation. These effects are noticeable as the degradation in structure of the Everglades Ridge and Slough environment and associated Tree Islands. In aquatic systems water flow is of fundamental importance in shaping the structure and function of the ecosystem. The organized patterns of parallel orientation of ridges, sloughs, and tear-drop shaped tree islands along historic flow paths attest to the importance of water movement in structuring this system. Our main objective was to operate and manage the LILA facility to provide a broad potential as a research platform for an integrated group of multidisciplinary, multi-agency scientists collaborating on multifunctional studies aimed primarily at determining the effects of CERP water management scenarios on the ecology of tree islands and ridge and slough habitats. We support Everglades water management, CERP, and the Long-Term Plan by defining hydrologic regimes that sustain healthy tree islands and ridge and slough ecosystems. Information gained through this project will help to reduce the uncertainty of predicting the tree island and ridge and slough ecosystem response to changes in hydrologic conditions. Additionally, we have developed the LILA site as a visual example of Everglades restoration programs in action.

An Alternative Goodness-of-fit Test for Normality with Unknown Parameters

Goodness-of-fit tests have been studied by many researchers. Among them, an alternative statistical test for uniformity was proposed by Chen and Ye (2009). The test was used by Xiong (2010) to test normality for the case that both location parameter and scale parameter of the normal distribution are known. The purpose of the present thesis is to extend the result to the case that the parameters are unknown. A table for the critical values of the test statistic is obtained using Monte Carlo simulation. The performance of the proposed test is compared with the Shapiro-Wilk test and the Kolmogorov-Smirnov test. Monte-Carlo simulation results show that proposed test performs better than the Kolmogorov-Smirnov test in many cases. The Shapiro Wilk test is still the most powerful test although in some cases the test proposed in the present research performs better.