This thesis presents a design for an Intelligent Educational System to support the teaching of design evaluation in engineering. The design consists of a simple computerbased tool (or 'learning environment') for displaying and manipulating infonnation used in the course of problem solving, with a separate dialogue component capable of discussing aspects of the problem and of the problem solving strategy with the user. Many of the novel features of the design have been incorporated in a prototype system called WOMBAT. The main focus of this research has been on the design of the dialogue component. The design of the dialogue component is based on ideas taken from recent work on rational agency. The dialogue component has expertise in engaging in dialogues which support collaborative problem solving (involving system and user) in domains characterised as justified beliefs. It is capable of negotiating about what to do next and about what beliefs to take into account in problem solving. The system acquires problem-related beliefs by applying a simple plausible reasoning mechanism to a database of possible beliefs. The dialogue proceeds by turn-taking in which the current speaker constructs their chosen utterance (which may consist of several propositions and questions) and explicitly indicates when they have finished. When it is the system's turn to make an utterance, it decides what to say based on its beliefs about the current situation and on the likely utility of the various possible responses which it considers appropriate in the circumstances. Two aspects of the problem solving have been fully implemented. These are the discussion about what criteria a decision should be based on and the discussion about what decision step should be taken next. The system's contributions to the interaction are opportunistic, in the sense that at a dialogue level the system does not try to plan beyond the current utterance, and at a problem solving level it does not plan beyond the next action. The results of a formative evaluation of WOMBAT, in which it was exposed to a number of engineering educators, indicate that it is capable of engaging in a coherent dialogue, and that the dialogue is seen to have a pedagogical purpose. Although the approach of reasoning about the next action opportunistically has not proved adequate at a problem solving level, at a dialogue level it yields good results.

The purpose of my dissertation study is to better understand the educational experiences of undergraduate engineering students within non-curricular learning environments, specifically in the form of extracurricular engineering groups or programs. I first conducted a content analysis of engineering education literature to identify where engineering design learning occurs, and to synthesize the implications of studies regarding engineering design learning. Aiming to fill a gap in the literature regarding non-curricular learning contexts, this study investigated what extracurricular groups and programs can educationally provide undergraduate engineering students by observing and interviewing students engaging in these environments. This study also aimed to identify if and how engineering students find navigational flexibility within engineering curricula, and how non-curricular learning environments might provide navigational flexibility. With regard to where engineering design learning occurs, the literature points to various educational contexts that effectively deliver engineering design education. Strategies that involve authentic and longer-term engineering design experiences tend to be the most impactful in terms of student outcomes and perceptions, however those experiences are not always implementable at larger scale. More traditional educational approaches to engineering design learning, though less impactful, are still effective delivery methods for introducing key aspects of engineering design education (e.g. modeling, global/societal/economic/environmental factors, communication skills). However, there was limited literature regarding more non-curricular learning experiences, such as learning in designed settings, outreach learning, learning media, and everyday informal learning. This literature review is one of the first attempts towards synthesizing where and how engineering design learning occurs, and has identified a significant gap in the literature regarding non-curricular educational settings. Addressing the identified gap in engineering education literature regarding non-curricular learning experiences, this dissertation study investigated five non-curricular engineering learning sites for undergraduate engineering students at a large research-driven state institution. Informed by the preliminary findings of a pilot study, I first investigated the salient features of engineering-related non-curricular activities from the students' perspectives using a self-directed learner autonomy framework to guide the study. Students participating in extracurricular engineering environments exhibited strong attributes of self-directed learners, particularly a willingness and ability to be challenged and to learn. The educational environments of the extracurricular opportunities cultivated these self-directed learning attributes by providing students a space to be exposed to an engineering community, authentic engineering work, and accessible resources. Findings from this portion of the dissertation indicated necessary modifications to the self-directed learner autonomy framework used to guide this study. The modified framework contributes a possible approach towards future assessment or research pursuits regarding non-curricular learning experiences in engineering. I also investigated the role non-curricular activities play in providing engineering students navigational flexibility through engineering curricula. Extracurricular engineering environments afford navigational flexibility by offering students opportunities to work on motivating challenges with and among supportive communities. By providing a space for students to express their engineering selves in primarily self-directed ways, extracurricular engineering experiences cultivate students' drive to find and pursue personally meaningful curricular and non-curricular educational experiences. However, institutional barriers, particularly time constraints and institutionally recognized achievements, stifle students' flexibility and willingness to pursue personally meaningful experiences. The findings of this study have helped uncover the various affordances non-curricular learning experiences provide engineering students, but more importantly, have identified the institutional barriers that prevent students from taking full advantage of non-curricular learning experiences. Based on these findings, I recommend that university and program level structures be reevaluated to encourage and provide students with more flexibility to find personalized learning experiences in and out of the classroom. / Ph. D.

A key advantage of Additive Manufacturing (AM) is the opportunity to design and fabricate complex structures that cannot be made via traditional means. However, this potential is significantly constrained by the use of a facet-based geometry representation (e.g., the STL and the AMF file formats); which do not contain any volumetric information and often, designing/slicing/printing complex geometries exceeds the computational power available to the designer and the AM system itself. To enable efficient design and fabrication of complex/multi-material complex structures, several algorithms are presented that represent and process solid models as a set of voxels (three-dimensional pixels). Through this, one is able to efficiently realize parts featuring complex geometries and functionally graded materials. This thesis specifically aims to explore applications in three distinct fields namely, (i) Design for AM, (ii) Design for Manufacturing (DFM) education, and (iii) Reverse engineering from imaging data wherein voxel-based representations have proven to be superior to the traditional AM digital workflow. The advantages demonstrated in this study cannot be easily achieved using traditional AM workflows, and hence this work emphasizes the need for development of new voxel based frameworks and systems to fully utilize the capabilities of AM. / MS / Additive Manufacturing(AM) (also referred to as 3D Printing) is a process by which 3D objects are constructed by successively forming one-part cross-section at a time. Typically, the input file format for most AM systems is in the form of surface representation format (most commonly. STL file format). A STL file is a triangular representation of a 3-dimensional surface geometry where the part surface is broken down logically into a series of small triangles (facets). A key advantage of Additive Manufacturing is the opportunity to design and fabricate complex structures that cannot be made easily via traditional manufacturing techniques. However, this potential is significantly constrained by the use of a facet-based (triangular) geometry representation (e.g., the STL file format described above); which does not contain any volumetric (for e.g. material, texture, color etc.) information. Also, often, designing/slicing/printing complex geometries using these file formats can be computationally expensive. To enable more efficient design and fabrication of complex/multi-material structures, several algorithms are presented that represent and process solid models as a set of voxels (three-dimensional pixels). A voxel represents the smallest representable element of volume. For binary voxel model, a value of ‘1’ means that voxel is ‘on’ and value of 0 means voxel is ‘off’. Through this, one is able to efficiently realize parts featuring complex geometries with multiple materials. This thesis specifically aims to explore applications in three distinct fields namely, (i) Design for AM, (ii) Design for Manufacturing (DFM) education, and (iii) Fabricating models (Reverse engineering) directly from imaging data. In the first part of the thesis, a software tool is developed for automated manufacturability analysis of a part that is to be produced by AM. Through a series of simple computations, the tool provides feedback on infeasible features, amount of support material, optimum orientation and manufacturing time for fabricating the part. The results from this tool were successfully validated using a simple case study and comparison with an existing pre-processing AM software. Next, the above developed software tool is implemented for teaching instruction in a sophomore undergraduate classroom to improve students’ understanding of design constraints in Additive Manufacturing. Assessments are conducted to measure students’ understanding of a variety of topics in manufacturability both before and after the study to measure the effectiveness of this approach. The third and final part of this thesis aims to explore fabrication of models directly from medical imaging data (like CT Scan and MRI). A novel framework is proposed which is validated by fabricating three distinct medical models: a mouse skull, a partial human skull and a horse leg directly from corresponding CT Scan data. The advantages demonstrated in this thesis cannot be easily achieved using traditional AM workflows, and hence this work emphasizes the need for development of new voxel based frameworks and systems to fully utilize the capabilities of AM.

The design of an aerospace vehicle system is a complex integration process driven by technological developments, stakeholder and mission needs, cost, and schedule. The vehicle then operates in an equally complex context, dependent on many aspects of the environment, the performance of stakeholders and the quality of the design itself. Satisfying the needs of all stakeholders is a complicated challenge for designers and engineers, and stakeholder requirements are, at times, neglected in design decisions. Thus, it is critical to examine how to better incorporate stakeholder requirements earlier and throughout the design process. The intent of this research is to (1) examine how stakeholder considerations are currently integrated into aerospace vehicle design practice and curricula, (2) design empirically-informed and theoretically-grounded educational interventions for an aerospace design capstone course, and (3) isolate the characteristics of the interventions and learning environment which support students’ integration of stakeholder considerations. The first research phase identified how stakeholder considerations are taken into account within an aerospace vehicle design firm and in current aerospace engineering design curricula. Interviews with aerospace designers revealed six conditions at the group, interaction and individual levels affecting the integration of stakeholder considerations. Examining current curricula, aerospace design education relies on quantitative measures. Thus, many students are not introduced to stakeholder considerations that are challenging to quantify. In addition, at the start of an aerospace engineering senior design capstone course, students were found to have some understanding of the customer and a few contextual considerations, but in general students did not see the impact of the broader context or of stakeholders outside of the customer. The second research phase comprised the design and evaluation of a Requirements Lab and Stakeholders in Design Labs, two in-class interventions implemented in a senior aircraft design capstone course. Further, a Stakeholders in Design rubric was developed to evaluate students’ design understanding and integration of stakeholder considerations and, as such, can be used as a summative assessment tool. The two interventions were evaluated using a multi-level framework to examine student capstone design projects, a written evaluation, and observations of students’ design team meetings. The findings demonstrated an increase in students’ awareness of a diverse group of stakeholders, but also perceptions that students appeared to only integrate stakeholder considerations in cases where interactions with stakeholders were possible and the design requirements had an explicit stakeholder focus. Particular aspects of the aircraft design learning environment such as the lack of explicit stakeholder requirements, the differences between the learning environment in the two semesters of the course, and the availability of tools impacted students’ integration of stakeholder considerations and overall effectiveness of the interventions. This research serves as a starting point for future research in pedagogical techniques and assessment methods for integrating stakeholder requirements into technology-focused design capstone courses. The results can also inform the vehicle design education of students and engineers from other disciplines.