Quantifying the impact of environmental policy on engineering design decisions

Whitefoot, Kate S University of Michigan 2011 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

In order to realize environmental goals, policymakers are increasingly creating measures to encourage the redesign of products to improve environmental performance. Developing an approach to evaluate the influence of these policies on firm design decisions requires modeling both the demand- and supply-side of the relevant industry well. A mature body of literature in economics focuses on modeling consumer preferences and firm decision-making, but econometrically representing engineering tradeoffs that govern design decisions remains a challenge. The engineering design literature explicitly models these tradeoffs but representations of consumer preferences and firm competition are often simplified. This dissertation presents a quantitative methodology for analyzing the impact of policies on engineering design decisions by integrating state-of-the art approaches from engineering design and economics. A model of the U.S. automotive industry is presented, representing consumer purchase decisions and firm design and pricing decisions for the full line of vehicles produced in a year. The methodology integrating engineering design models with economic analyses produces three synergistic contributions. First, the combined model allows for policy analysis of the full-scale automotive industry accounting for design options that may be profit-optimal given a possible policy even if the design options are not observable in current data. Second, the structure of the product-development process is used to address the difficulty of econometrically identifying demand parameters for design attributes. Third, a hybrid engineering-economics cost model is presented, using the econometric demand model to derive cost parameters for which engineering estimates are unavailable. The value of the developed methodology is demonstrated through three case studies. The combined model is used to evaluate U.S. fuel economy regulations in terms of the ability to produce gains in fuel economy and the impact on firm profits. Results illustrate that estimates of cost effectiveness are substantially sensitive to design options considered, suggesting that analyses ignoring these design changes considerably overestimate the costs of the regulations. This model is then extended to examine footprint-based fuel economy standards. Results indicate that these standards could encourage substantial increases in vehicle size that diminish gains in fuel economy. Finally, applications of the presented approach to environmental lifecycle assessment are demonstrated.

A Multi-Phase Exploration of Conceptualizations, Perceived Importance, and the Development of Empathy within Engineering

Hess, Justin L Purdue University 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Throughout the United States, there have been numerous calls for the development of well-rounded engineers through a more holistic engineering education. This dissertation is a collection of three independent but related studies exploring the role of a disposition that seems intimately connected to many skills described as necessary for the next generation of engineers within these calls: empathy. Each chapter of this dissertation provides unique insights on conceptualizations, perceptions of the importance, and the development of this phenomenon within engineering and engineering education. The first study investigates how empathy and care look within an engineering context through three separate but interrelated phases including (a) a summative content analysis of existing literature, (b) thematic analysis of small group interviews with engineering faculty, and (c) thematic analysis of written responses from practicing engineers to an open-ended question about empathy and care. Taken together, findings from these three phases demonstrate that although empathy and care have a place within engineering, conversations and awareness of these phenomena are not often explicitly stated within the literature or frequently addressed by engineers or engineering faculty. The second study explores the importance and existence of empathy and care within engineering practice. This study includes (a) thematic analysis of engineers' conceptualizations of empathy and care (n = 25), (b) phenomenological analysis of engineers' experiences of empathy and care within the workplace (n = 25), (c) exploratory factor analysis of an empathy and care survey (n = 1574), and (d) non-parametric testing of engineers' responses to the derived factor structure (n = 1481) to explore in what ways empathy and care are perceived as most important to engineering practice, and whether these perceptions vary by gender or years of work experience. Phenomenological analysis led to the emergence of 13 themes along four categories including (a) design outcomes, (b) personal outcomes, (c) relational outcomes, and (d) broader ideas. Non-parametric testing of the derived factor structure indicated that practicing engineers with greater years of work experience were more likely to perceive empathy and care as existing in engineering practice and as important to their work. The third study explores developments in undergraduate engineering students' perspective-taking tendencies after participating in an engineering ethics course. This study follows a concurrent mixed methodological research approach, first analyzing students' changes in a psychometric instrument (the Interpersonal Reactivity Index) along with evaluative changes in an ethics transfer case study, and second through thematic analysis of critical incidents derived from semi-structured interviews with course participants (n = 19). Quantitative findings indicated that students' self-reported perspective-taking tendencies increased over the course of the semester and qualitative findings indicated there were six fundamentally distinct causes of this increase and five distinct types of outcomes related to perspective-taking. Taken together, the results from these three inter-related studies highlight contextual considerations for allowing empathy to manifest itself within engineering, potential pathways and improved outcomes of an empathically guided engineering process, and educational design strategies for prompting critical experiences to develop engineering students' empathic tendencies.

Thinking Like an Engineer: Interrogating the Epistemic Hierarchy of a Professional Engineering Community of Practice

Kramer, Amy K ProQuest Dissertations & Theses The Ohio State Uni 2022 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

What it means to ?think like an engineer? and what ?counts? as engineering knowledge is a foundational part of engineering culture. What engineers value as knowledge and how they act on that knowledge impacts nearly every aspect of engineering design and practice as well as who enters and persists in engineering. Researchers have shown that within engineering, there is a socially constructed epistemic hierarchy; technical knowledge and analytical or rational ways of knowing are consistently constructed as superior.This hierarchy is problematic because it 1) functions in ways that devalue social considerations from engineering work, and 2) has been constructed by the dominant social groups in engineering (i.e., White, cisgender, men) and works to maintain the exclusivity of engineering. In this interpretive study informed by feminist theories, I explore the beliefs, reported practices, and identities of engineers to interrogate how the epistemic hierarchy of engineering is reproduced within a professional engineering community of practice. I found that the epistemic hierarchy of engineering was indeed pervasive, and it was reproduced via beliefs about the definition of engineering and the role of objectivity in engineering. The most pervasive shared beliefs used to resist the epistemic hierarchy of engineering were rooted in capitalistic or neoliberal ideology, which is troublesome because it is often at odds with social justice and equity initiatives. I also found that the engineers who identified as women or gender non-binary were more likely to strongly identify with normative ways of knowing in engineering (i.e., analytical thinking) than their majority counterparts, which provides insight into the role of privilege in how engineering identity is negotiated in terms of the epistemic hierarchy. Ultimately, this work implies that we need to "make space? for students and professionals to critically reflect on what it means to think like an engineer to promote a more socially conscious and inclusive engineering field.

Examining Underemphasized Engineering Practices: Engineering Students' Alignment With Curricular Emphases and Engagement With Divergent Thinking

Clancy, Shannon M University of Michigan ProQuest Dissertations & Th 2024 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Engineering students need to prepare to address increasingly complex, contextual, and ambiguous problems in their future careers. Many students pursue engineering to improve societal problems and create innovative solutions. Yet, divergent thinking needed for creativity, and the consideration of multiple social issues and a variety of contexts, is underemphasized in engineering education. Lack of this essential training hampers students' abilities to address sociotechnical problems and heightens risk of harm from their engineering solutions. Without social, contextual, and divergent thinking emphases during engineering training, historically marginalized students invested in these practices may be deterred from pursuing and persisting in engineering education. My dissertation addresses the underemphasis of divergent thinking and other important skills to address complex problems in engineering education through three distinct studies within a variety of engineering student experiences. In my first study, I explored undergraduate mechanical engineering students' perceptions of knowledge, skills, and messaging in their core engineering courses, how these emphases may (mis)align with students' interests and values, and the impact of (mis)alignments on engineering students' persistence, sense of fit, and career intentions in engineering. Leveraging multiple semi-structured interviews with 30 undergraduate mechanical engineering students, I identified curricular emphases students explicitly described as emphasized or not/seldom emphasized in the mechanical engineering curriculum. I also characterized (mis)alignments between student interests and the curriculum and students' compensatory actions to enable them to persist in engineering and aspiring career interests in response to their (mis)alignments. My second study examined mechanical engineering students' divergent thinking. I utilized semi-structured interviews to capture the depth and nuance of how and why students said they did or did not consider multiple options in several key points during varied engineering projects. I identified influential resources and structural, environmental, individual, and team factors that affected mechanical engineering students' divergent thinking. I leveraged narrative inquiry to elucidate how these intersecting factors affected students' divergent thinking. From these findings, I constructed narratives that also serve as pedagogical tools to support students and faculty learning about intentional divergent thinking in engineering. My final study examined patterns of divergent thinking in engineering students' idea development. The A/B study design compared student iterative concept transformation on their own and using Design Heuristics cards. In the first round, they generated and selected an early concept, and iteratively transformed it without the tool four times. In the second round, students returned to their selected early concept and transformed it four more times using up to seven Design Heuristics cards. I analyzed over 500 concepts, identifying both sequential and non-sequential links across concept generation sessions and developed Design Transformation Diagrams to identify patterns across students' idea changes. My findings showed iterative transformations in combination with Design Heuristics can assist students in deeper exploration and create more varied and distinct concepts without an escape from the influence of existing concepts. My work in this dissertation provides insights into engineering creativity and other underemphasized practices important to educating engineers for today's complex sociotechnical problems. Engineering education must provide opportunities, scaffolding, and practice where students can develop their knowledge and skills and experience more alignment of their values and interests in engineering curricula. Based on my findings, I recommend tools, strategies, and curricular changes to improve scaffolding of creative and sociotechnical processes that must be enhanced and more explicitly and intentionally integrated into today's engineering curricula. .

Engineering stratified tissues for in situ cartilage regeneration

Sharma, Blanka The Johns Hopkins University 2006 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Patients suffering from cartilage damage due trauma or disease may benefit from biological replacements developed using tissue engineering techniques. Current tissue engineering strategies, however, often fail to restore the unique structural organization of the tissue leading to inferior function. Articular cartilage has a zonal architecture consisting of superficial, middle, and deep chondrocytes, followed by transition and integration into the underlying bone. The cell layers have different morphological, biochemical and mechanical properties, which are crucial to the physiological role of the tissue. Regeneration of the structural organization will be important to the success of cartilage tissue engineering. The overall goals of this thesis were to engineer structurally organized cartilage and osteochondral tissues, study heterotypic cell interactions relevant to cartilage repair and homeostasis, and design a practical tissue engineering strategy that can be clinically applied. It was hypothesized that a scaffold that encourages the appropriate cell and matrix organization, and facilitates relevant cell-cell interactions, may improve the functional outcome of tissue engineered cartilage. Multi-layered hydrogels were developed using photopolymerization techniques to engineer cartilage with the zonal properties of the native tissue. Superficial, middle, and deep zone chondrocytes were isolated and encapsulated in respective layers of a tri-layered hydrogel. The polymerization conditions supported cell viability and matrix synthesis. Cell and matrix products were confined to their respective layers resulting in stratified, heterogeneous cartilage with similar zonal characteristics of the native tissue. Further coculture studies revealed that interactions between zone-specific cells affected the biological and mechanical properties of engineered cartilage. Specifically, superficial cells regulated deep cell proliferation and increased deep cell biosynthetic activity in a bi-layered hydrogel. The stratified cartilage constructs demonstrated greater mechanical strength compared to homogeonous cartilage constructs, implying potential benefits to isolating and organizing zonal chondrocytes for tissue engineering purposes. A bi-layering technique was then applied to the engineering of osteochondral composite tissues. Chondrocytes were cocultured with bone-marrow derived mesenchymal stem cells (MSCs) or fully differentiated osteoblasts. In both cases, cartilage and bone like matrix were spatially maintained in the distinct layers. However, MSCs uniquely stimulated the chondrocytes in this coculture system, evidenced by increased production of proteoglycan and collagen type II. (Abstract shortened by UMI.).

Engineering problem finding in high school students

Franske, Benjamin James University of Minnesota 2009 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The purpose of this study was to explore the engineering problem finding ability of high school students at three high schools in Minnesota. Students at each of the three schools had differing backgrounds including pre-engineering coursework, traditional technology education coursework and advanced science coursework. Students were asked to find problems in two different engineering scenarios which were presented to them on a paper and pencil instrument. Responses were scored by a panel of judges based on measures of creativity (flexibility, fluency, originality and elaborateness) and analyzed based on demographic data including gender, prior coursework and school. In addition student responses were categorized and evaluated qualitatively based on school and gender of respondent. Quantitative results indicate that the most consistent predictor of creativity in engineering problem finding scenarios was the number of advanced science classes. Specific measures of creativity included other significant predictors but advanced science coursework was the most consistent across all measures and scenarios. The qualitative results showed striking differences in the responses from students at different schools. Students from schools with a pre-engineering and advanced science emphasis found similar categories of problems and had a similar view of the purview of engineers while students with a technology education background focused on a rather different set of problems and had a much narrower view of engineering. Results show clear differences in the types of problems found by students at these three high schools as well as their understanding of the scope of engineering problems. Educators need to become more aware of the importance of problem finding in engineering and better encourage the development of problem finding skills among their students. Specifically, technology education teachers may need supplemental professional development related to the scope of engineering and engineering problem finding as well as how these concepts might be infused into their curriculum and encouraged among their students.

Local Strain Engineering of Large-Area Epitaxial MoS2 on GaN Microstructures

김희경 울산과학기술원 Graduate School of Semiconductor Materials 2026 국내석사

A framework for applying concurrent engineering principles to the construction industry

AbulHassan, Hisham Sherfi The Pennsylvania State University 2001 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The most crucial stages in the product life cycle are the product planning and design stages. It is here that decisions are made that have the greatest impact on the final product and its operating characteristics. The manufacturing industry has successfully applied downstream information to the planning and design stages of the product life cycle through a process called concurrent engineering. The benefits of concurrent engineering include reduced cost, increased speed, and improved quality. The objective of this research was to develop and test a framework for implementing concurrent engineering in construction. A case study research methodology was used to study the effect of concurrent engineering on construction projects. The principles of concurrent engineering were applied to a conceptual model of the building process to create a concurrent engineering model of the building process. A set of twenty-six rules that differentiate a concurrent engineering building project from a non-concurrent engineering project was derived from the revised functions of the conceptual model. A concurrent engineering index was also created to measure the level of concurrent engineering on a building project. Nineteen construction projects were studied to measure the effect of concurrent engineering on project performance. Evidence was found of a positive correlation between the concurrent engineering index and increased project delivery speed and improved project quality. While such a correlation was not found with the respect to project unit cost, it was apparent that unit cost remained constant with an increasing concurrent engineering index. Lastly, the more influential concurrent engineering rules were written in the form of a set of guidelines to be implemented in a construction company in order to achieve improved project unit cost, project delivery speed, and project quality.

Motivation of Students Who Switch from Engineering to Engineering Technology

Ramirez, Nichole Purdue University ProQuest Dissertations & Theses 2017 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

A set of studies is reported describing the demographics, outcomes, and motivations of students who start in engineering and switch their major to engineering technology. There has been extensive research in engineering persistence, but little focus has been given to the "T" in STEM. Most research combines technology with other science and mathematics fields, ignoring the unique characteristics of this population. Exploring this population at the intersection of Engineering and Engineering Technology is particularly valuable as the lines between the disciplines are blurred. For example, the Engineering Technology Council of the American Society for Engineering Education markets the tagline: "The Degree is Engineering Technology, the Career is Engineering.". With engineering technology enrollment on the rise, we may expect to see more changes in engineering technology education. For example, Purdue's Polytechnic Institute (a 2015 rebrand from the College of Technology) is part of an initiative to open a technology-focused high school as a direct pathway into Purdue. In this particular situation, it has yet to be seen where students will go -- engineering, technology, or somewhere else. This research helps inform policy decisions related to such a pathway. The goal of this research was to determine why students choose to matriculate in engineering and then decide to change majors to engineering technology. Using a mixed methods approach, this work includes three studies focused on academic outcomes and student motivation. The studies draw upon Social Cognitive Career Theory (SCCT) and Expectancy-Value Theory (EVT), focusing on intrinsic factors like interest and self-efficacy and extrinsic factors like social influence and career goals. The first study employs data sampled from the Multiple Institution Database for Investigating Engineering Longitudinal Development (MIDFIELD; https://engineering.purdue.edu/MIDFIELD) to determine demographic and academic factors associated with leaving engineering and switching to technology as well as their graduation outcomes. The next study focuses on motivation constructs related to SCCT and EVT. A survey instrument was e-mailed to Purdue students who switched from engineering to engineering technology, and it was also used as a recruitment tool for the third study. The third and final study employed a thematic analysis to explore the reasons why students switched from engineering to engineering technology. Statistical methods include regression analysis of longitudinal data, correlational analysis of theoretical constructs consisting of Likert-scale survey items, and thematic analysis of open-ended survey responses and semi-structured interviews. Based on data from MIDFIELD, students disproportionately switched to ET than any other major, comprising over 40% of all students who leave engineering went to technology. Self-reported survey data from students who switched from engineering to engineering technology at Purdue University revealed that students rated themselves higher on general self-efficacy than on engineering self-efficacy. These students were also intrinsically motivated and still identified with engineering. Of those survey respondents, thirteen participated in interviews as part of the third study. Themes that emerged from their surveys and interviews included pre-college expectations, parental input, alternative paths to career goal, and barriers to persist in engineering and to switch to engineering technology. Students sought engineering technology as an alternative pathway to their engineering-related career goal when their college engineering experience did not match their pre-college expectations. Because of that, students faced barriers to persisting in engineering, like their academic performance. They also faced obstacles to pursuing ET, including the stigma others associate with switching. Gathering input from their parents helped them in their decision-making process. The results support findings from other studies and provided context for students' motivations to switch. Ultimately, students maintain their engineering interests and career goals but accomplish their goals through a different context. This work has implications for students, advisors, parents, and policy makers. Advisors in high school and college can improve their ability to identify the reasons why students switch and which students may be likely to switch. This set of studies is the first step towards understanding students who start in engineering and switch their major to engineering technology.

Experts and novices: Differences in their use of mental representation and metacognition in engineering design

Dixon, Raymond Anthony University of Illinois at Urbana-Champaign 2010 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Research shows that mental representation such as analogical reasoning is a fundamental cognitive tool for design problem solving (Daugherty & Mentzer, 2008; Hey, Lensey, Agogino, & Wood, 2008; Lewis, 2008). Not much is known, however, about the way students and professional engineers actively generate and change their mental representation when solving a engineering design problem. There are very few studies that show how different types of mental representations; such as metaphors, propositions, and analogies; interplay with higher order cognitive processes; such as planning, monitoring, and evaluation; as engineering designers navigate their problem and solution spaces. This empirical study investigated the mental representation and metacognitive regulation of student and professional engineers while they solve an engineering design problem. The intent is to gain a deeper insight in the differences that exists in the cognitive process of engineering students and professional engineers. The research questions guided this study were (a) How do the mental representations (propositions, metaphors, and analogies) of student and professional engineers differ in their problem and solution spaces in terms of their frequency, types, and attributes? (b) How does the metacognitive regulation (planning, monitoring, and evaluation) of student and professional engineers differ in their problem and solution spaces in terms of their frequency and characteristics? and (c) How do the mental representation and metacognitive regulation of students and professional engineers relate to their overall engineering design strategy? Concurrent and retrospective verbal protocols were collected from six mechanical engineering students and four professional mechanical engineers as they solved an engineering design problem. Their verbalizations were audio recorded, transcribed, and coded. The conclusions drawn from the data were: the use of mental representations such as propositions, analogies, and metaphors by experts and novice engineering designers in the different mental spaces are important in engineering design. Expert engineering designers use analogies differently in their solution space than do novice engineering designers. Expert engineering designers rely on within-domain analogies, between-domain analogies, heuristics, and formulas differently from novice engineering designers. In engineering design evaluation plays a larger role in the solution space of expert designers while novice designers tend to do more planning in the problem space. Finally, based on the findings recommendations are provided for engineering and technology education curriculum and instruction, engineering practice in industry, and for future research.