Decision support system for form verification of manufactured parts.

The form verification of manufactured parts is a process composed of a set of operations that are expensive and yet add no value to the product. Yet, the resources used to inspect the parts add a small but significant amount of noise that can affect the outcome of the process. For this reason, this research provides guidelines to effectively perform the inspection process by suggesting new mathematical models and approaches that can be used for the creation of a decision support system that can assist in the verification of the accuracy of machined parts.This research proposes two approaches to improve the robustness of the mathematical models from the noise induced by the inspection process. The Dynamic Angle Approach (DAA) and the Free Form Orientation approach (FFO) presented here focus on finding the parameters of the axes and origin of the form that counteract the inaccuracies of the inspection equipment.In summary, this research suggests formalized methods for feature extraction, sampling, path planning, and form fitting, although the last mentioned received the most attention. It is believed that this comprehensive, integrated analysis will lead to the development of a decision support system.The proposed approaches and mathematical models were verified using measurements from features that were perfectly aligned with the coordinate system of the inspection equipment and from features that were intentionally misaligned. The results showed that the models were accurate and robust enough to estimate the parameters and zone of error of the form features and they performed better than existing models.The main goal of this research is to develop procedures that are simple to implement but at the same time are robust enough to provide reliable information that help the metrologist to make accurate decisions about the inspected parts. Form features such as spheres, cylinders, cones, frustums, and torus forms are commonly used to design complex parts. However, the procedures to verify most of these form features have not been developed yet by the national standards. Therefore, this research proposes new mathematical models that combine the concepts of analytic geometry and optimization to provide optimal solutions

A design-with-features approach for rotational machined components

A major problem in integrating Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) arises from the difference in thinking between the design and manufacturing people. Designers think of designing a new product in terms of its intended function whereas manufacturing engineers think in terms of decomposing a product design into a set of manufacturing operations. Feature Recognition and Designing with Features have been recognised as alternative approaches to the integration of design and manufacturing functions. In this thesis the second approach has been investigated by developing a feature-based front-end to a CAD solid modeller. This produces the geometric representation of the component in terms of manufacturing features and processes, and simultaneously captures this information in a form suitable for an outline process plan. [Continues.

He Scattering from Compact Clusters and from Diffusion-Limited Aggregates on Surfaces: Observable Signatures of Structure

The angular intensity distribution of He beams scattered from compact clusters and from diffusion limited aggregates, epitaxially grown on metal surfaces, is investigated theoretically. The purpose is twofold: to distinguish compact cluster structures from diffusion limited aggregates, and to find observable {\em signatures} that can characterize the compact clusters at the atomic level of detail. To simplify the collision dynamics, the study is carried out in the framework of the sudden approximation, which assumes that momentum changes perpendicular to the surface are large compared with momentum transfer due to surface corrugation. The diffusion limited aggregates on which the scattering calculations were done, were generated by kinetic Monte Carlo simulations. It is demonstrated, by focusing on the example of compact Pt Heptamers, that signatures of structure of compact clusters may indeed be extracted from the scattering distribution. These signatures enable both an experimental distinction between diffusion limited aggregates and compact clusters, and a determination of the cluster structure. The characteristics comprising the signatures are, to varying degrees, the Rainbow, Fraunhofer, specular and constructive interference peaks, all seen in the intensity distribution. It is also shown, how the distribution of adsorbate heights above the metal surface can be obtained by an analysis of the specular peak attenuation. The results contribute to establishing He scattering as a powerful tool in the investigation of surface disorder and epitaxial growth on surfaces, alongside with STM.Comment: 41 pages, 16 postscript figures. For more details see http://www.fh.huji.ac.il/~dan

Applications of Virtual Reality

Information Technology is growing rapidly. With the birth of high-resolution graphics, high-speed computing and user interaction devices Virtual Reality has emerged as a major new technology in the mid 90es, last century. Virtual Reality technology is currently used in a broad range of applications. The best known are games, movies, simulations, therapy. From a manufacturing standpoint, there are some attractive applications including training, education, collaborative work and learning. This book provides an up-to-date discussion of the current research in Virtual Reality and its applications. It describes the current Virtual Reality state-of-the-art and points out many areas where there is still work to be done. We have chosen certain areas to cover in this book, which we believe will have potential significant impact on Virtual Reality and its applications. This book provides a definitive resource for wide variety of people including academicians, designers, developers, educators, engineers, practitioners, researchers, and graduate students

Tangible user interfaces : past, present and future directions

In the last two decades, Tangible User Interfaces (TUIs) have emerged as a new interface type that interlinks the digital and physical worlds. Drawing upon users' knowledge and skills of interaction with the real non-digital world, TUIs show a potential to enhance the way in which people interact with and leverage digital information. However, TUI research is still in its infancy and extensive research is required in or- der to fully understand the implications of tangible user interfaces, to develop technologies that further bridge the digital and the physical, and to guide TUI design with empirical knowledge. This paper examines the existing body of work on Tangible User In- terfaces. We start by sketching the history of tangible user interfaces, examining the intellectual origins of this field. We then present TUIs in a broader context, survey application domains, and review frame- works and taxonomies. We also discuss conceptual foundations of TUIs including perspectives from cognitive sciences, phycology, and philoso- phy. Methods and technologies for designing, building, and evaluating TUIs are also addressed. Finally, we discuss the strengths and limita- tions of TUIs and chart directions for future research

Development of Sustainable Methodologies in Product Design, Manufacturing and Education

The influence of sustainability in product design and manufacturing processes can be considered from two different points of view: the design of sustainable products and the sustainable manufacturing of those products. Of course, a basic assumption for the aforementioned elements to be realized is the appropriate training and education for sustainability of the young designers and engineers. In this research, sustainability has been applied to many fields, including design, manufacturing and education acting as an umbrella which covers all the three elements and has as the main target to promote sustainability. In today’s world, in which a considerable number of contrasting signs reveal that our society is currently contributing to the planet’s collapse, a new kind of engineer is needed, an engineer who is fully aware of what is going on in society and who has the skills to deal with aspects of sustainability. According to the literature review on the state-of-the-art associated to the subject, in the current research were developed tools and methodologies for the promotion of sustainability aspects that are related to product design, manufacturing and education. Product DesignThe research work was based on a framework, which was built according to the direct communication between users and designers. There is a need for a cultural transformation, which can be focused on consumers and promote the needed behavioural change. Moreover there is a need for a cultural transformation on the role of designers and engineers to the product design process, with an aim to address sustainability as well as emerging priorities from societal to environmental challenges. New tools and methodologies were generated, in order to promote sustainability to the users/citizens bringing them inside to the product design process, giving them the opportunity to be a vital part of it. ManufacturingSustainable manufacturing faces new challenges for developing predictive models and optimization techniques in order to produce more products. The first part of the current is related to the drilling process and cutting tool technology. The creation of mathematical models focused on maximization of productivity and cost reduction by identifying crucial parameters and processes influencing manufacturing effectiveness. The second part of the current research is associated to the development of models used by CAD/ CAM that allow a rapid improvement and an efficient design and manufacture.EducationThe third aspect of the research is associated with the education related to sustainability. The engineering students should develop sustainability competences such as critical thinking, systemic thinking, obtaining values consistent with the sustainability paradigm, except of just taking a course on sustainability, focus on the technological role of sustainability. Focus on that the current research was based on sustainable characteristics such as a) remote control freeware applications, b) share of valuable resources, c) distance learning methodology and d) active participation of the students.<br /

Elastic timber gridshells. from the finding form process to the erection of efficient lightweight structures

Doctoral Thesis (International Doctoral Programme in Sustainable Built Environment)Elastic timber gridshells emerged in the last century, essentially related to ephemeral buildings, setting a ‘new’ benchmark for lightweight, cost-effective, sustainable and temporary constructions. Timber gridshells are adaptable and can be used in rehabilitated buildings as well as, new buildings, new systems like roofs, or as small additions in nonstructural elements and act as a simple partition. However, the main feature is not its use, but its shape and how it allows some freedom in its design; an attractive characteristic for designers due to its structural behaviour. Based on the advantages of the structural system, it should be expected that timber gridshells have a wider presence in contemporary architecture. However, this is not the case, there are very few examples being built. One reason why this happens, is because of the difficulty to reach the desired design since there is a lack of information about the tools that can help to define such complex systems. Until today, the design and construction of elastic, or post-formed timber gridshells, have only been based on a case to case basis and have not been studied or used as a type of structure that can be repeated in several different applications. The aim of this thesis is to contribute to answer this difficulty, i.e. working on overcoming the lack of design guidelines, by presenting a state of the knowledge on elastic timber gridshells and by case studies analysing the process involved in building this kind of a structures. The thesis is addressing elastic timber gridshells, from the design phase to the construction phase. The results obtained show that this type of structure can be very interesting at a functional level with numerous tectonics characteristics that make elastic timber gridshells attractive as a structural solution in contemporary architecture.As malhas elásticas de madeira surgiram no século passado, essencialmente relacionadas com construções temporárias, estabelecendo uma "nova" referência para construções leves, econômicas, sustentáveis e efêmeras. As malhas de madeira são adaptáveis e podem ser usadas em edifícios a reabilitar, bem como, novos edifícios, coberturas, ou em pequenas modificações como elementos não estruturais. No entanto, a principal característica não é seu uso, mas sua geometria e como isso permite uma enorme liberdade formal torna-se uma característica atraente para todos os projetistas. Com base nas vantagens deste sistema estrutural, é de esperar que as malhas elásticas de madeira tivessem uma presença mais ampla na arquitetura contemporânea. Contudo, não é o caso, existem poucos exemplos construídos. Um motivo para isso acontecer é a dificuldade em projetar as formas desejadas, pois existe uma lacuna de informação sobre as ferramentas que podem ajudar a definir estas geometrias complexas. Por exemplo, as ferramentas baseadas em softwares computacionais têm um grande potencial para o processo de projeção das malhas de madeira nas fases de projeto e construção, onde a localização da malha e a otimização ocorrem, seguidas por um processo de produção industrial. Até hoje, o projeto e a construção destas estruturas, foram estudados apenas de caso a caso e não foram estudados ou usados como um tipo de solução que pode ser repetida em várias aplicações diferentes. O objetivo desta dissertação é contribuir para a resolução desse problema, ou seja, trabalhar na superação da falta de diretrizes de projeto, apresentando um estado do conhecimento sobre as malhas elásticas de madeira e analisando e explicando o processo envolvido na construção deste tipo de estruturas. Esta tese aborda as malhas elásticas de madeira, desde a fase de projeto até à fase de construção. Os resultados obtidos mostram que este tipo de estrutura pode ser muito interessante a um nível funcional, com numerosas características com valor tectônico que tornam as malhas elásticas de madeira atrativas como uma solução estrutural na arquitetura contemporânea.This work it was financed by FEDER funds through the Competitively Factors Operational Programme - COMPETE and by national funds through FCT – Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007633. The support of the Foundation for Science and Technology (FCT) through doctoral fellowship SFRH/BD/104677/2014 is grateful

ARCHITECTURAL MODELS AS LEARNING TOOLS

This book shows a variety of educational experiments that explore the use and meaning of ‘Architectural models as learning tools in education’both practically and theoretically