Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 131-139).

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The application of heterogeneous materials has become common in modern product design such as composites and porous media. Computational design tools for such materials, with higher complexity than the traditional homogeneous ones, will be a critical component in the realization of the heterogeneity systematically. It is foreseen that computer-aided design (CAD) systems will include computer-aided materials design modules in future so that the design of functional materials and structures can be integrated for optimal product design. The traditional CAD systems model three-dimensional (3D) geometry at macro-scales with boundary representation (B-Rep), whereas computer-aided materials design is concerned with the specification of material composition at scales ranging from nano-, meso-, to micro-. Thus, multi-scale CAD systems are desirable for the integration of product and materials information. The existing B-Rep based modeling scheme needs to be extended to incorporate heterogeneous material compositions. The new modeling scheme should also support seamless zoom-in and zoom-out operations in multi-scale CAD systems. Recently, a multi-scale model, dual-Rep, was proposed to represent geometry and material property distribution implicitly. The core part of dual-Rep is a new basis function called surfacelet. Surfacelet is able to represent boundary information more efficiently than the traditional wavelets, while keeping a unified form with wavelets so that the role exchange of boundary and internal structures during zooming operations is enabled. A surfacelet transform is able to represent microstructure distributions in 3D images with surfacelet coefficients. In this dissertation, three enabling techniques for surfacelet-based heterogeneous materials modeling are developed. First, a method of inverse surfacelet transform is developed such that the original images can be reconstructed from the surfacelet coefficients. The surface integrals of voxel (i.e., volumetric pixel) values are obtained from the surfacelet coefficients using the one-dimensional inverse wavelet transform. The images are then reconstructed by solving linear equations from discretized surface integrals. The prior knowledge of material properties and distributions is applied to solve the under-constrained problems. Second, composite surfacelets with the combinations of different types of primitive surfacelets are created to increase the flexibility of the surfacelet transform with potentially fewer surfacelets and improved reconstruction accuracy. Third, a multi-scale materials modeling method is proposed to support interactive design and visualization of material microstructures at multiple levels of details. It has the capability to support seamless zoom-in and zoom-out. This method provides a feature-based design approach based on the surfacelet basis.

The inadequate infrastructure that exists for seamless project team communications has its roots in the problems arising from fragmentation, and the lack of effective co-ordination between stages of the construction process. The use of disparate computer-aided engineering (CAE) systems by most disciplines is one of the enduring legacies of this problem and makes information exchange between construction team members difficult and, in some cases, impossible. The importance of integrating modelling techniques with a view to creating an integrated product and process model that is applicable to all stages of a construction project's life cycle, is being recognised by the Construction Industry. However, improved methods are still needed to assist the developer in the definition of information model structures, and current modelling methods and standards are only able to provide limited assistance at various stages of the information modelling process. This research investigates the role of system integration by reviewing product and process information models, current modelling practices and modelling standards in the construction industry, and draws conclusions with similar practices from other industries, both in terms of product and process representation, and model content. It further reviews various application development tools and information system requirements to support a suitable integrated information structure, for developing an integrated product and process model for design and construction, based on concurrent engineering principles. The functional and information perspectives of the integrated model, which were represented using IDEFO and the unified modelling language (UML), provided the basis for developing a prototype hyper-integrated product and process information modelling system (HIPPY). Details of the integrated conceptual model's implementation, practical application of the prototype system, using house-building as an example, and evaluation by industry practitioners are also presented. It is concluded that the effective integration of product and process information models is a key component of the implementation of concurrent engineering in construction, and is a vital step towards providing richer information representation, better efficiency, and the flexibility to support life cycle information management during the construction stage of small to medium sized-building projects.

Thesis (MEng)--University of South Australia, 1994

Thesis (MEng (Electronic Eng))--University of South Australia, 1994

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (M.Sc.)--Memorial University of Newfoundland, 1999. / Restricted until June 2000. Bibliography: leaves [79]-88.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 91-94).

M.Sc. (Computer Science) / This dissertation presents a method for learning from existing building designs and generating new building layouts. Generating fully furnished building layouts could be very useful for video games or for assisting architects when designing new buildings. The core concern is to drastically reduce the workload required to design building layouts. The implemented prototype features a Computer Aided Design system, named CABuilD that allows users to design fully furnished multi-storey building layouts. Building layouts designed using CABuilD can be taught to an Artificial Immune System. The Artificial Immune System tracks information such as building layouts, room sizes and furniture layouts. Once building layouts has been taught to the artificial immune system, a generation algorithm can utilise the information in order to generate fully furnished building layouts. The generation algorithm that is presented allows fully furnished buildings to be generated from high-level information such as the number of rooms to include and a building perimeter. The presented algorithm differs from existing building generation methods in the following ways: Firstly existing methods either ignore building perimeters or assume a buildings perimeter is a rectangle. The presented method allows the user to specify a closed polygon as a building perimeter which will guide the generation of the building layout. Secondly existing generation methods tend to run from a set of rules. The implemented system learns from existing building layouts, effectively allowing it to generate different building types based on the building layouts that were taught to the system. Thirdly, the system generates both the building layout as well as the furniture within rooms. Existing systems only generate the building layout or the furniture, but not both. The prototype that was implemented as a proof of concept uses a number of biologically inspired techniques such as Ant algorithms, Particle Swarm Optimisation and Artificial Immune Systems. The system also employs multiple intelligent agents in order to furnished rooms. The prototype is capable of generating furnished building layouts in merely a few seconds, much faster than a human could design such a layout. Possible improvements and future work is presented at the end of the dissertation.