Engineering Commons^™

Race, Class And Gender In Engineering Education: A Quantitative Investigation Of First Year Enrollment, Canek Moises Luna Phillips

Open Access Dissertations

Research explanations for the disparity across both race and gender in engineering education has typically relied on a deficit model, whereby women and people of color lack the requisite knowledge or psychological characteristics that Whites and men have to become engineers in sufficient numbers. Instead of using a deficit model approach to explain gender and race disparity, in the three studies conducted for this dissertation, I approach gender and race disparity as the result of processes of segregation linked to the historic and on-going perpetuation of systemic sources of oppression in the United States. In the first study, I investigate …

Organizing Historical Agricultural Data And Identifying Data Integrity Zones To Assess Agricultural Data Quality, Elizabeth Marie Hawkins

Open Access Dissertations

As precision agriculture transitions into decision agriculture, data driven decision- making has become the focus of the industry and data quality will be increasingly important. Traditionally, yield data cleaning techniques have removed individual data points based on criteria primarily focused on the yield values. However, when these methods are used, the underlying causes of the errors are often overlooked and as a result, these techniques may fail to remove all of the inaccurate data or remove “good” data. As part of this research, an alternative to data cleaning was developed. Data integrity zones (DIZ) within each field were identified by …

A Cross-Sectional And Mixed-Method Assessment Of Safety Culture And Safety Climate At A Regional Airline, Micah S. Walala

Open Access Dissertations

The researcher applied a mixed methods approach to conduct a cross-sectional assessment of the safety culture, safety climate, and SMS at a regional airline in the United States. Data collection techniques were comprised of interview, on-line-survey, and a focus group activity. Participants in the current study were maintenance technicians, flight attendants, dispatchers, pilots, and managers. Results indicated significant differences of perception of safety climate, safety culture, and Safety Management System between the maintenance technicians and flight attendants. The length of time a participant had worked at the subject airline and age of the participant appeared to be significant factors of …

Learning The Language Of Academic Engineering: Sociocognitive Writing In Graduate Students, Catherine G. P. Berdanier

Open Access Dissertations

Although engineering graduate programs rarely require academic writing courses, the indicators of merit in academic engineering, such as journal publications, successful grants, and doctoral milestones (e.g. theses, dissertations) are based in effective written argumentation and disciplinary discourse. Further, graduate student attrition averages 57% across all disciplines, with some studies classifying up to 50% of these students as “ABD” (All But Dissertation.) In engineering disciplines specifically, graduate attrition rates across the U.S. average 36% (both Master’s and PhD students), according to the Council of Graduate Schools. The lack of socialization is generally noted as a main reason for graduate attrition, one …

Estimating The Water Quality Condition Of River And Lake Water In The Midwestern United States From Its Spectral Characteristics, Jing Tan

Open Access Dissertations

This study focuses on developing/calibrating remote sensing algorithms for water quality retrieval in Midwestern rivers and lakes. In the first part of this study, the spectral measurements collected using a hand-held spectrometer as well as water quality observations for the Wabash River and its tributary the Tippecanoe River in Indiana were used to develop empirical models for the retrieval of chlorophyll (chl) and total suspended solids (TSS). A method for removing sky and sun glint from field spectra for turbid inland waters was developed and tested. Empirical models were then developed using a subset of the field measurements with the …

Manifold Learning Based Spectral Unmixing Of Hyperspectral Remote Sensing Data, Jun-Hwa Chi

Open Access Dissertations

Nonlinear mixing effects inherent in hyperspectral data are not properly represented in linear spectral unmixing models. Although direct nonlinear unmixing models provide capability to capture nonlinear phenomena, they are difficult to formulate and the results are not always generalizable. Manifold learning based spectral unmixing accommodates nonlinearity in the data in the feature extraction stage followed by linear mixing, thereby incorporating some characteristics of nonlinearity while retaining advantages of linear unmixing approaches. Since endmember selection is critical to successful spectral unmixing, it is important to select proper endmembers from the manifold space. However, excessive computational burden hinders development of manifolds for …

Adaptive Targeting: Engaging Farmers To Assess Perceptions And Improve Watershed Modeling, Optimization, And Adoption Of Agricultural Conservation Practices, Margaret Mccahon Kalcic

Open Access Dissertations

Targeting agricultural conservation practices to farmland that has the greatest impact on surface water quality has received wide support from scientists and watershed managers. The targeting approach has, however, been politically contentious as many believe farmers will oppose the approach on grounds such as privacy invasion and unfair distribution of government incentives. Targeting conservation practices using complex optimization models has become common in the scientific community, and yet targeted results are underutilized in practice because of difficulties such as knowledge transfer and absence of a political framework for their use. For targeting to be successful, it must be politically supported …

Mispronunciation Detection For Language Learning And Speech Recognition Adaptation, Zhenhao Ge

Open Access Dissertations

The areas of "mispronunciation detection" (or "accent detection" more specifically) within the speech recognition community are receiving increased attention now. Two application areas, namely language learning and speech recognition adaptation, are largely driving this research interest and are the focal points of this work.

There are a number of Computer Aided Language Learning (CALL) systems with Computer Aided Pronunciation Training (CAPT) techniques that have been developed. In this thesis, a new HMM-based text-dependent mispronunciation system is introduced using text Adaptive Frequency Cepstral Coefficients (AFCCs). It is shown that this system outperforms the conventional HMM method based on Mel Frequency Cepstral …

Design, Development, And Testing Of A Conformal Power Control Interface For Thrust Vectoring Aircraft, David Rozovski

Open Access Dissertations

Over the last five years, a new power control inceptor for tiltrotor aircraft, known as the Rotational Throttle Interface (RTI) was designed and built. Prior to the RTI, no tiltrotor inceptor had been able to simultaneously indicate both the direction and magnitude of thrust conformally. The purpose of the RTI is to provide an interface that maps to the intended vehicle response throughout ALL ranges of operation. Doing so is expected to reduce confusion that may have contributed to several tiltrotor accidents

Two tests were conducted with the RTI, one at the NASA Vertical Motion Simulator, and one at Canada's …

Simulating Land Use Land Cover Change Using Data Mining And Machine Learning Algorithms, Amin Tayyebi

Open Access Dissertations

The objectives of this dissertation are to: (1) review the breadth and depth of land use land cover (LUCC) issues that are being addressed by the land change science community by discussing how an existing model, Purdue's Land Transformation Model (LTM), has been used to better understand these very important issues; (2) summarize the current state-of-the-art in LUCC modeling in an attempt to provide a context for the advances in LUCC modeling presented here; (3) use a variety of statistical, data mining and machine learning algorithms to model single LUCC transitions in diverse regions of the world (e.g. United States …