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This thesis implemented a prototype of an expert system shell for support of engineering design activities in the way of logic programming. The development of the system is based on the theoretical framework for knowledge-based system design and the formal modeling concepts. Under the above methodologies, two knowledge representations, production rule system and system entity structure, are incorporated into the knowledge base for figuring design structures. Here the production system scheme is employed for synthesis of design models represented in the system entity structure. The whole system is coded in Turbo Prolog and a specific domain knowledge, namely a local area network, is currently used as a testbed environment.

‘Lean’ or ‘lean thinking’ refers to an improvement philosophy which focuses on the fulfilment of customer value and the reduction of waste. This philosophy is credited with the extraordinary rise of Toyota, one of the largest and most profitable automotive companies in the world. This thesis presents a pioneering study investigating how lean thinking should be applied to product development (PD). The aim of the research was to construct an innovative model which supports the implementation of lean thinking in PD. This was achieved through progressive collaboration with practitioners from European manufacturing companies. The model provides a process for the conceptual development of an engineering project, and is composed of phases and activities for which methodologies have been defined. The construction of the lean PD model was preceded by a systematic literature review and an industrial field study, wherein 36 semi-structured interviews were conducted in five manufacturing companies in Europe. The constructed model was later implemented on two real-life case studies via action research. The two conducted case studies involved the product architecture design for a car audio head unit and the development of a helicopter engine. It was concluded that the lean PD model addresses various industrial challenges including customer value, communication, and innovation. Furthermore, by focusing on conceptual design, the lean PD model is expected to reduce design rework. As a result of the positive effects of the model, one of the companies involved intends to implement the lean PD model further, and wishes to extend the model to the rest of the organisation. This research makes four main contributions: (1) a novel lean PD model; (2) a number of tools developed to support the model; (3) a framework for lean PD enablers; and (4) a categorisation of challenges faced by PD in industry used to verify the relevance of the lean PD model.

Traditional methods for specifying thermal inputs for the structural fire analysis of buildings assume uniform burning and homogeneous temperature conditions throughout a compartment, regardless of its size. This is in contrast to the observation that accidental fires in large, open-plan compartments tend to travel across floor plates, burning over a limited area at any one time. This thesis reviews the assumptions inherent in the traditional methods and addresses their limitations by proposing a methodology that considers travelling fires for structural design. Central to this work is the need for strong collaboration between fire safety engineers to define the fire environment and structural fire engineers to assess the subsequent structural behaviour. The traditional hypothesis of homogeneous temperature conditions in postflashover fires is reviewed by analysis of existing experimental data from wellinstrumented fire tests. It is found that this assumption does not hold well and that a rational statistical approach to fire behaviour could be used instead. The methodology developed in this thesis utilises travelling fires to produce more realistic fire scenarios in large, open-plan compartments than the conventional methods that assume uniform burning and homogeneous gas phase temperatures which are only applicable to small compartments. The methodology considers a family of travelling fires that includes the full range of physically possible fire sizes iv within a given compartment. The thermal environment is split into two regions: the near field (flames) and the far field (smoke away from the flames). Smaller fires travel across a floor plate for long periods of time with relatively cool far field temperatures, while larger fires have hotter far field temperatures but burn for shorter durations. The methodology is applied to case studies showing the impact of travelling fires on generic concrete and steel structures. It is found that travelling fires have a considerable impact on the performance of these structures and that conventional design approaches cannot automatically be assumed to be conservative. The results indicate that medium sized fires between 10% and 25% of the floor area are the most onerous for a structure. Detailed sensitivity analyses are presented, showing that the structural design and fuel load have a larger impact on structural behaviour than any numerical or physical parameter required for the methodology. This thesis represents a foundation for using travelling fires for structural analysis and design. The impact of travelling fires is critical for understanding true structural response to fire in modern, open-plan buildings. It is recommended that travelling fires be considered more widely for structural design and the structural mechanics associated with them be studied in more detail. The methodology presented in this thesis provides a key framework for collaboration between fire safety engineers and structural fire engineers to achieve these aims.

Cellular activities are composite responses to stimuli from the surroundings. Materials for biological applications, therefore, must be designed with care such that undesired interactions between cells and the materials will not be elicited while cellular responses that are beneficial to the dedicated applications are promoted. Efforts have been made to construct such materials based on both synthetic polymers and natural polymers including poly(ethylene glycol) (PEG) and proteins. In particular, recombinant proteins have drawn great interest for their similar biocompatibility to natural proteins and the uniformity of material properties that is found in manufacturing of synthetic polymers. Recombinant proteins are designed at the DNA level, which allows precise control over the translated protein sequence. By assembling encoded DNA sequences of amino acids with desired functional groups or protein domains conferring desired functionalities, a recombinant protein-based material can be tailored. In this dissertation, works toward developing functional biomaterials based on both synthetic polymers and recombinant proteins are presented.<br>The first part of this thesis encompasses the development of a new thiol-based crosslinking approach to achieve independent control over degradability and mechanical properties of a hydrogel system. Thiol chemistry was chosen as the focus here because it can easily be incorporated into recombinant protein designs by inserting cysteine residues. In addition, the low frequency of cysteine residues in natural proteins can reduce unwanted reactions between the hydrogel material and encapsulated biomolecules or cells. We utilized divinyl sulfone (DVS) to form thioether crosslinking through thiol-ene addition and ferric ethylenediaminetetraacetic acid (ferric EDTA) to make disulfide crosslinking via thiol oxidation. By controlling the ratio between the non-reducible thioether bonds to reducible disulfide bonds, hydrogels with similar mechanical properties can be made with different degradability in reducing conditions. Accelerated degradation and increased release of encapsulated dextran was observed in response to an extracellular reducing condition. Good viability of encapsulated fibroblasts also suggested high cytocompatibility of the crosslinking approach. This work demonstrated the potential of thiol crosslinking by DVS and ferric EDTA for making redox-responsive drug delivery vehicles and tissue engineering scaffolds.<br>In the second part, we developed protein adhesives using thiol- or catechol-based adhesion. Every year more than 310 million surgeries are performed around the world, and more than 50% of these surgeries used sutures or staples for wound closure. Surgical sealants or adhesive can be applied together with sutures and staples to mitigate the risk of infection. Protein-based adhesives could have better biocompatibility than synthetic polymer-based adhesives and have the potential of providing biochemical cues for cellular responses. Many adhesive proteins have been found in nature. Among them, mussel adhesive proteins have been actively studied for their outstanding underwater adhesion. The capability of being able to cure in a wet environment is critical for an ideal surgical sealant and adhesive. Mussels uses both thiols and a catechol, 3, 4-dihydroxyphenylalanine (DOPA), to achieve underwater adhesion. Inspired by mussel adhesive proteins and modular recombinant design, we developed two proteins harboring thiol or DOPA groups with highly similar amino acid sequences. The adhesion performance, including curing kinetics, adhesion strength, and cytocompatibility, were compared between the two proteins. The similarity in the protein sequences allows us to focus on the performance difference between thiol- and DOPA-based adhesion. We also showed that a synergistic increase in the adhesion strength can be achieved when the two proteins are combined. This increase indicates a cross-reaction between thiol and DOPA groups. Our results provide insights into selecting the chemistry for designing adhesives based on the needs of the applications.<br>In the last part, we studied the lower critical solution temperature (LCST) behavior of elastin-like polypeptides (ELPs) with a series of ELPs with rationally designed charge distributions and chain lengths. The LCST behavior of ELPs are controlled by multiple factors including the amino acid composition, ELP chain length, protein concentration, salt identity, salt concentration, and pH of the solution. Fusion of other non-ELP recombinant protein domains to ELPs have also been shown to influence the LCST behavior of the fusion ELP protein. Inspired by this effect, we explored the use of short non-ELP sequences as a new way to tailor the LCST behavior of ELP-based proteins. We designed the non-ELP and the ELP sequences with different pH-dependent charge states and showed that pH sensitivity was introduced to the LCST behavior by electrostatic and hydrophobic interactions between the non-ELP and ELP sequences. The electrostatic interactions can be shielded by the ionic strength in the protein solution. The pH sensitivity was introduced by the non-ELP sequences, and this sensitivity decreased when the relative length of the ELP domain increased. We also found that the hydrophobicity of the non-ELP sequences changes the interactions between the proteins and Hofmeister ions in solution. Our results demonstrated the potential of using non-ELP sequences as a new factor in controlling the LCST behavior of ELP proteins.<br><br>

Engineers Talk Be it through conversations, meetings, informal discussion, phone calls or E-Mail, Engineering Design Communication is the main tributary for the sharing of knowledge, thoughts and ideas, and therefore, fundamental to Engineering Work. An engineer spends a significant portion of their day communicating as they 'fill in the gaps' left by formal documentation and processes. It is thereby, an inherent source of explicit design rationale that relates to (and very often supplements) Engineering Records and their generation. Engineering Design Communication is not only central for Engineering Work and Records but also offers potential - through aggregation - to reveal underlying features, patterns and signatures that could aid current and future Engineering Project Management. As Engineering Design Communication plays such a pivotal role, it comes as no surprise that there is much extant research. The majority of this is descriptive and has focused on identifying patterns in engineers' communication behaviour as well as analysing the utility of currently employed communication tools/mediums (such as, E-Mail and meetings). However, little prescriptive research - through either a tool or process - has been undertaken. This may be due to the considerable challenges facing research in this field such as the need to maintain a high-level of Engineering Context, ensure the right engineers are able to participate and associate the communication with its respective Engineering Records. All of which, has to be achieved within an Engineering Context where teams are becoming larger, more mobile, multi-disciplinary & distributed, and often performing variant or incremental design. Although, it is argued that Social Media has the potential to militate these challenges through the use of technologies that provide agile development, support for ubiquitous computing and sharing of multimedia. Therefore, this thesis investigates how Social Media can be used to support Engineering Design Communication. This is achieved through the elicitation and synthesis of the requirements for supporting Engineering Design Communication, and consideration of the effective application of the Social Media. This forms the basis from which a Social Media approach to support Engineering Design Communication is created and then instantiated within a tool called PartBook. PartBook has been developed iteratively and involved an industrial study to evaluate and improve functionality. It has since been used within an eleven week Formula Student project involving thirty-four students from multiple engineering disciplines in a distributed working environment. The analysis of which addresses the validation of the requirements that has led to amendments and generation of new requirements as well as evaluation of the Social Media approach that has led to insights into the potential impact such a tool could bring to Engineering Work, Records and Project Management.

With the continuous growth in computing power, numerical optimisation is increasingly applied in shape optimisation using Computational Fluid Dynamics (CFD). Since CFD computations are expensive, gradient-based optimisation is preferable when the number of design variables is large. In particular the recent progress with adjoint solvers is important, as these solvers allow to compute the gradients at constant computational cost regardless of the number of design variables, and as a consequence enable the use of automatically derived and rich design spaces. One of the crucial steps in shape optimisation is the parametrisation of the geometry, which directly determines the design space and thus the nal results. This thesis focuses on CAD-based parametrisations with the CAD model continuously updated in the design loop. An existing approach that automatically derives a parametrisation from the control points of a net of B-Spline patches is extended to include NURBS. Continuity constraints for water-tightness, tangency and curvature across patch interfaces are evaluated numerically and a basis for the resulting design space is computed using Singular Value Decomposition (SVD). A CAD-based shape optimisation framework is developed, coupling a flow solver, an adjoint solver, the in-house CAD kernel and a gradient-based optimiser. The flow sensitivities provided by the adjoint solver and the geometric sensitivities computed through automatic differentiation (AD) are assembled and provided to the optimiser. An extension to maintain the design space and hence enables use of a quasi-Newton method such as the BFGS algorithm is also presented and the convergence improvements are demonstrated. The framework is applied to three shape optimisation cases to show its effectiveness. The performance is assessed and analysed. The effect of parameters that can be chosen by the user are analysed over a range of cases and best practice choices are identified.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by William Waldron Tice. / M.S.

As maker spaces, engineering design curricula, and other hands-on active learning tasks become more popular in science classrooms, it is important to consider what students are intended to take away from these tasks. Many teachers use engineering design tasks as a means of teaching students more general science principles. However, few studies have explored exactly how the design of these activities can support more generalized student learning and transfer. Specifically, research has yet to sufficiently investigate the effects of task design components on the learning and transfer processes that can occur during these kinds of tasks. This dissertation explores how various task manipulations and focusing processes affect how well students can learn and transfers science concepts from an engineering design task. I hypothesized that learning goals that focus students on the deep structure of the problem, and contrasting cases that help students notice that deep structure, would aid learning and transfer. In two experimental studies, students were given an engineering design task. The first study was a 2x2 between subjects design where goal where goal (outcome or learning) and reflection (on contrasting cases or the engineering design process) were manipulated. A subsequent second study then gave all students contrasting cases to reflect on, and only the goal manipulation was manipulated. Results showed that learning goals improved student performance on a transfer task that required students to apply the deep structure to a different engineering design task. In the second study, learning goals improved student performance on a transfer test. Transfer performance in both studies was predicted by the ability to notice the deep structure during the reflection on contrasting cases, even though noticing this structure did not differ by goal condition. Students with a learning goal valued the learning resources they were given more during the engineering design activity, and this perceived value of resources was linked to greater learning. A qualitative case study analysis was then conducted using video data from the second study. This case study investigated noticing processes during the building process, partner dialogue, and resource use. This analysis showed how high transfer pairs were better able to focus on the deep structure of the problem. Results suggest that what students noticed didn’t differ much between the various pairs. However, high transfer pairs were better able to focus on the deep structure through establishing a joint understanding of the deep structure, sustaining concentration on that deep structure during the cases reflection, referencing resources to identify features to test, and then systematically testing those features to identify their relevance. These processes are discussed in relation to how they differ in low transfer pairs. This dissertation consists of four chapters: an intro, two standalone journal articles, and a conclusion. The first chapter provides a conceptual framing for the two journal articles, and discusses the findings from these articles in conversation. The second chapter describes the two empirical studies investigating how task goals and contrasting cases affect learning, and transfer from an engineering design task. The third chapter describes the comparative case study of how mechanisms of focusing on the deep structure differ between high and low transfer pairs. Finally, the fourth conclusion chapter discusses the implications of the work from both of these papers.