This dissertation focuses on how requirements for a new software development system are elicited and what pitfalls could cause a software development project to fail if the said requirements are not captured correctly. A number of existing requirements elicitation methods, namely: JAD (Joint Application Design), RAD (Rapid Application Development), a Formal Specifications Language (Z), Natural Language, UML (Unified Modelling Language) and Prototyping are covered. The aforementioned techniques are then integrated into existing software development life cycle models, such as the Waterfall model, Rapid Prototyping model, Build and Fix model, Spiral model, Incremental model and the V-Process model. Differences in the domains (knowledge and experience of an environment) of a client and that of the software development team are highlighted and this is done diagrammatically using the language of Venn diagrams. The dissertation also refers to a case study highlighting a number of problems during the requirements elicitation process, amongst other the problem of tacit knowledge not surfacing during elicitation. Two new requirements elicitation methodologies are proposed namely: the SRE (Solitary Requirements Elicitation) and the DDI (Developer Domain Interaction) methodology. These two methods could potentially be more time consuming than other existing requirements elicitation methods, but the benefits could outweigh the cost of their implementation, since the new proposed methods have the potential to further facilitate the successful completion of a software development project. Following the introduction of the new requirements elicitation methods, they are then applied to the aforementioned case study and highlight just how the hidden domain of the client may become more visible, because the software development team has gained a deeper understanding of the client’s working environment. They have therefore increased their understanding of how the final product needs to function in order to fulfil the set out requirements correctly. Towards the end of the dissertation a summary and a conclusion as well as future work that could be undertaken in this area are provided. / Computer Science / M. Sc. (Computer Science)

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This project investigates the use of Rapid Prototyping (RP), with specific focus on Three Dimensional Printing (3DP), in the manufacture of complex shaped advanced composite parts, using variants of the Resin Transfer Moulding (RTM) method of composite manufacture. This study developed design guidelines, cost models and a process chain by studying data obtained by making example parts, from literature and consultation with industry. Advanced composite materials offer some of the best low weight and high specific strength properties for the solution of design problems. A major disadvantage of these processes, however, is the low production rates possible and the need of costly moulds. The 3DP technologies combined with the RTM composite process was found to enable a lowering of costs and increase in productivity if smaller batch sizes are considered. The most meaningful area of application for RP techniques seems to be for smaller and more complex components. The geometrical freedom allowed by RP technologies allowed the manufacture of parts which are challenging to manufacture by conventional technology such as CNC machining. Example part case studies were completed for a simple part utilising the one sided mould Resin Infusion RTM variant as well as for a complex part utilising the closed mould Vacuum Assisted Resin Transfer Moulding (VARTM) process variant. During these two case studies it was clear that proper part infusion with resin is critical for the manufacture of good quality composite parts free of voids and dry spots. It is possible to improve the resin infusion by correct placement of resin inlet and outlet ports as well as resin channels incorporated in the mould. Correct placement of these features for the case studies was obtained through simulations done with RTM-Worx software. Results also indicated that another useful application of RP technology to RTM is the manufacture of disposable cores for parts with thick cross sections. Resin channels were included on the surface of these cores to improve the mould filling with resin and consequently part quality. An early cost estimation model, based on the work of Veldsman (1995), was developed for the combined RP and RTM manufacturing process. This model may help designers to eliminate expensive design features and enables a quick cost comparison with competing processes. Drawbacks of applying RP techniques to RTM include the limited lifetime of moulds produced with 3DP and the size and accuracy limitations of the RP t echnology. / AFRIKAANSE OPSOMMING: Hierdie projek handel oor die toepassing van die drie-dimensionele druk metode van Snel-Prototipering (Rapid Prototyping) op die vervaardiging van komplekse gevorderde saamgestelde materiaal komponente met die Hars-Inspuit Giet (Resin Transfer Moulding) metode. Die projek behels die opstel van ontwerpsriglyne, koste-modelle en ’n proses-ketting deur data te bestudeer wat bekom is deur middel van die vervaardiging van eksperimentele parte, literatuurstudie asook raadpleging met individue in die industrie. Gevorderde saamgestelde materiale verskaf van die beste sterk, dog ligte oplossings vir sekere ontwerpsprobleme. ’n Ernstige nadeel van hierdie materiale is egter die stadige produksietempo moontlik en die vereiste van duur gietstukke. Die Snel- Prototipering metodes, gekombineerd met ’n saamgestelde materiaal vervaardigingsproses, maak laer kostes met beter produktiwiteit moontlik indien ontwerpers die part grootte- en akkuraatheidsbeperkings in ag neem. Die mees betekenisvolle area van toepassing blyk kleiner en meer komplekse komponente te wees. Die vryheid in geometrie wat moontlik gemaak word deur die Snel- Prototipering tegnologie laat die vervaardiging toe van parte wat uitdagend is om te vervaardig met konvensionele tegnologie soos CNC masjinering. ’n Gevallestudie is voltooi vir ’n eenvoudige part vervaardig met die enkelkant gietstuk vakuum-infusie weergawe van die Hars-Inspuit Giet metode asook vir ’n komplekse part wat vervaardig is met die geslote gietstuk Vakuum Hars-Inspuit Giet weergawe van die basiese metode. Dit het tydens die twee gevallestudies duidelik geword dat deeglike hars infusie van kritieke belang is vir die vervaardiging van goeie kwaliteit parte sonder enige droë kolle of lugruimtes. Dit is moontlik om die hars infusie te verbeter deur hars inlate en uitlate asook hars kanale in die korrekte posisies te plaas. Die korrekte posisies vir hierdie komponente is verkry deur middel van ’n reeks simulasies met die RTM-Worx sagteware. Resultate dui ook daarop dat Snel-Prototipering tegnologie handig te pas kom by die vervaardiging van verbruikbare kerne vir saamgestelde materiaal parte met groter diktes. Hars kanale kan maklik op die kerne se oppervlak geskep word om die hars verspreiding en gevolglik part kwaliteit te verbeter. ’n Vroeë kostevoorspellings model, gebaseer op werk voltooi deur Veldsman (1995), is saamgestel vir die gekombineerde Snel-Prototipering en Hars-Inspuit Giet proses. Hierdie model kan gebruik word om duur ontwerpsbesonderhede op parte te elimineer en om ’n vinnige koste vergelyking met ander vervaardigingsprosesse te toon. Nadele van die toepassing van Snel-Prototipering tegnieke op Hars-Inspuit Giet sluit die beperkte gietstuk-leeftyd en beperkte akkuraatheid in.

Approved for public release; distribution is unlimited / This thesis builds upon work previously done in the development of the Computer Aided Prototyping System (CAPS) and the Prototype System Description Language (PSDL), and presents a conceptual design for the Software Base Management System (SBMS) component of CAPS. The SBMS is the most critical component of CAPS as it will coordinate the retrieval and integration of Ada software modules. A robust SBMS that enables a software system designer to successfully retrieve reusable Ada components will expedite the prototype development process and enhance designer productivity. Implementation of the conceptual design will be the basis for further work in this area. (Ada is a registered trademark of the United States Government, Ada Joint Program Office.) / http://archive.org/details/conceptualdesign00gali / Lieutenant Commander, United States Navy

Approved for public release; distribution is unlimited / The Computer Aided Prototyping System (CAPS) and the Prototype System Description Language (PSDL) represent a pioneering effort in the field of software development. The implementation of CAPS will enable software engineers to automatically validate design specifications and functional requirements early in the design of a software system through the development and execution of a prototype of the system under construction. Execution of the prototype is controlled by an Execution Support System (ESS) within the framework of CAPS. One of the critical elements of the ESS is the Static Scheduler which extracts critical timing constraints and precedence information about operators from the PSDL source that describes the prototype. The Static Scheduler then uses this information to determine whether a feasible schedule can be built, and if it can, constructs the schedule for operator execution within the prototype. / http://archive.org/details/staticschedulerf00marl / Lieutenant Commander, United States Navy

A novel paste deposition process was developed to widen the range of possible materials and applications. This experimental process developed an increasingly complex series of additive manufacturing machines, resulting in new combinations of novel materials and deposition paths without sacrificing many of the design freedoms inherit in the craft process. The investigation made use of open-source software together with an approach to programming user originated infill geometries to form structural parts, differing from the somewhat automated processing by 'closed' commercial RP systems. A series of experimental trials were conducted to test a range of candidate materials and machines which might be suitable for the PDM process. The combination of process and materials were trailed and validated using a series of themed case studies including medical, food industry and jewellery. Some of the object created great interest and even, in the case of the jewellery items, won awards. Further evidence of the commercial validity was evidenced through a collaborative partnership resulting in the development of a commercial version of the experimental system called Newton3D. A number of exciting potential future directions having been opened up by this project including silicone fabrics, bio material deposition and inclusive software development for user originated infills and structures.

Aneurisma de Aorta Abdominal (AAA) é definido como uma dilatação localizada e permanente da parede arterial, geralmente com ocorrência entre as artérias renais e as ilíacas, como conseqüência do enfraquecimento dessa parede ou devido a uma solicitação anormal sobre sua estrutura normal. Essa afecção acomete principalmente a população idosa acima de 65 anos de idade, tendo como principais fatores de risco: tabagismo, hipertensão arterial, histórico familiar e doença obstrutiva crônica pulmonar. A prevalência está aumentando nos últimos anos, havendo uma duplicação dos casos diagnosticados nos Estados Unidos (Bonamigo e Von Ristow, 1999). Hoje o AAA é a 13ª causa de morte nos Estados Unidos, em homens com mais de 65 anos e no caso de aneurisma roto, é a 3ª causa de morte súbita nos Estados Unidos. A mortalidade global do AAA roto está em torno de 80% nos países que têm verificação sistemática e compulsória da causa de óbitos. Isto ocorre devido ao fato de uma hemorragia substancial intra-abdominal geralmente ser acompanhada de atraso no transporte e diagnóstico, e da necessidade de cirurgia de emergência em pacientes idosos que, freqüentemente, tem uma significativa comorbidade renal e cardiopulmonar. Acredita-se que a formação e o crescimento do aneurisma de aorta abdominal são acompanhados do crescimento da tensão na parede da aorta e/ou de uma diminuição da capacidade do tecido de suportar tal tensão. A ruptura ocorre quando a tensão atuante na parede excede a tensão que pode ser suportada pelo tecido. O risco de ruptura aumenta com o crescimento do tamanho do aneurisma, da tensão na parede e é agravado quando associado à hipertensão arterial. No estudo foram obtidos dados morfológicos da região torácica de um paciente com a utilização de tomografia computadorizada multi-fatias. Essas imagens DICOM (Comunicação de Imagens Digitais em Medicina) foram tratadas para selecionar apenas a região de interesse, obtendo-se um modelo tridimensional da aorta infra-renal e artérias ilíacas. A partir daí, foi confeccionado um modelo físico com a utilização de prototipagem rápida. Um simulador cardiovascular controlado por computador foi desenvolvido com o intuito de replicar características fisiológicas e patológicas do sistema cardiovascular humano. Esse modelo de aneurisma foi utilizado para simulação em bancada experimental, onde é possível reproduzir alguns parâmetros como pressão, fluxo, temperatura, resistência e complacência vascular. Também foi gerado um modelo computacional onde os parâmetros obtidos na simulação in vitro foram utilizados como condição de contorno inicial para o estudo computacional. Foram adotados padrões normotenso e hipertenso, e os resultados computacionais e experimentais foram analisados e comparados. O trabalho propõe uma metodologia que possibilite a obtenção de dados anatômicos e hemodinâmicos relativos ao segmento arterial acometido pela afecção, com o objetivo de fornecer informações adicionais no diagnóstico do aneurisma de aorta. / Abdominal Aortic Aneurysm (AAA) is defined as a focal and permanent dilatation of the arterial wall, most often occurring in between the renal and iliac arteries, as consequence of arterial wall weakness or because of an abnormal solicitation of that normal structure. This disease primarily affects elderly population over 65 years of age, and the most important risk factors are smoking, hypertension, family history and chronic obstructive pulmonary disease. In the last years, the prevalence is rising up almost twice the diagnosed cases in the United States (Bonamigo and Von Ristow, 1999). Nowadays, AAA is the thirtieth cause of death in the United States, in the elderly masculine population over 65 years of age, and in case of ruptured aneurysm, it is the third cause of sudden death in the United States. The overall mortality rate is about 80% in countries with systematic and compulsory evaluation of death cause. This is due to the fact that substantial intra-abdominal hemorrhage is often accompanied by delays in transport and diagnoses, and the need for emergency surgery in elderly patients that frequently have significant renal and cardiopulmonary comorbidity. It is suggested that the formation and expansion of the AAA are accompanied by wall stress increasing and / or decreasing in the tissue capacity to withstand this stress. The rupture occurs when the wall stress exceed the stress the tissue can accept. The risk of rupture increases with aneurysm expansion, wall stress increasing and it is exacerbated when associated with arterial hypertension. In the present work, morphological data from thoracic region of the patient was acquired by using multi-slice CT (Computed Tomography). These DICOM images had been treated to select only the interest region, getting a three-dimensional infra-renal aortic and iliac model. Then, it was made a physical model by using rapid prototyping. This model was used for in vitro experimentation in a computer controlled mock system, in which it is possible to replicate physiological and pathological characteristics of human being cardiovascular system. Some parameters such as pressure, flow, temperature, vascular resistance and compliance can be reproduced by the use of a mock circulatory system. These parameters were used as initial boundary conditions in order to calibrate a computational model. It was adopted normotensive and hypertensive patterns and computational and experimental results were analyzed and compared. The paper proposes a methodology which allows the acquisition of anatomical and hemodynamic data on the vessel segment affected by the pathology, with the goal of providing additional information in the diagnosis of aortic aneurysm.

A disponibilização de uma tecnologia de desenvolvimento recente, denominada neste trabalho de \"tecnologia de modelagem tridimensional física computadorizada\", ofereceu novos recursos para a obtenção de representações utilizadas no processo de desenvolvimento de projetos de produtos (modelos), que anteriormente era realizado utilizando-se exclusivamente procedimentos manuais de caráter artesanal. No entanto, existe uma diversidade de processos e de equipamentos que a utilizam, variando entre alguns simples e baratos, que podem obter objetos com algumas restrições, como de geometria, acabamento e resistência, e outros, extremamente complexos, que podem fornecer objetos com características excepcionais. Por outro lado, são utilizados diversos tipos de modelos ao longo do processo de projeto: alguns muito simples, empregados nas fases iniciais, e outros de maior complexidade, que representam o produto nas fases finais de seu desenvolvimento, entre os quais se encontra o modelo de aparência, que apresenta grande potencial de se beneficiar, em seu processo de confecção, das características particulares da referida tecnologia. O presente trabalho tem, portanto, o objetivo de apresentar um quadro detalhado da disponibilidade da tecnologia de modelagem tridimensional física computadorizada, particularmente no contexto brasileiro, a partir de pesquisa realizada com fabricantes, representantes comerciais, institutos de pesquisa e escolas de design, e de descrever as características formais e construtivas do modelo de aparência a partir de pesquisa bibliográfica e observações, de forma a identificar processos, equipamentos e procedimentos que podem ser adequados para atender à demanda por esse tipo de modelo em disciplinas de projeto de produto em escolas de design. / The availability of a new development technology, which in this text is referred to as \"computer-aided technology of physical three-dimensional modeling\", provides new resources for making representations used in product design development process (models), which previously, was almost exclusively completed through manual procedures. However, there are various types of processes and equipment that that technology which range from simple and inexpensive, that can obtain objects with some restrictions, such as geometry, finishing and resistance, and others that are extremely complex, that can provide objects with exceptional features. On the other hand, several types of models are used throughout the design process: some very simple, utilized in the early stages, and others of greater complexity, which represents the product in the final stages of its development, such as the mock-ups that have the greatest potential to benefit from the special characteristics of the technology previously mentioned. The objective of this research is to present a detailed picture of what is available for computerized three-dimensional modeling technology focused within the context of Brazil, based on research carried out with manufacturers, commercial representatives, institutes, research and design schools and describe the formal and constructive characteristics of the mock-ups, based on bibliographic research and observations, in order to identify processes, equipment and procedures that may be appropriate to meet the demand for this type of model in design schools.

Several technologies are being made available for the blind and the visually impaired with the use of infrared and sonar sensors, Radio Frequency Identification, GPS, Wi-Fi among others. Current technologies utilizing microprocessors increase the device's power consumption. In this project, a Verilog Hardware Language (VHDL) designed handheld device that autonomously guides a visually impaired user through an obstacle free path is proposed. The goal is to minimize power consumption by not using the usual microcontroller and replacing it with components that can increase its speed. Utilizing six infrared sensors, the handheld device is modeled after current technologies which use IR and sonar sensors which are reviewed in this project. By using behavioral modeling, an algorithm for obstacle avoidance and the generation of the obstacle free path is reduced using a K-map and implemented using a multiplexer. / by Ernesto Cividanes. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Este estudo tem por objetivo o desenvolvimento de uma metodologia de fabricação de sistemas Lab On Chip, úteis no estudo de processos celulares, a partir da adaptação de tecnologias próprias da microeletrônica. Foram exploradas todas as etapas envolvidas na fabricação de sistemas Lab On Chip em Poli-Di-Metil-Siloxano e desenvolvidos protocolos de fabricação de moldes, técnicas de moldagem e processos de ativação de PDMS com plasma de oxigênio para sua solda química sobre diferentes materiais, obtendo uniões irreversíveis que permitem a integração com outras tecnologias como a microeletrônica em silício e o encapsulamento com cerâmica verde, completando uma metodologia que permite a prototipagem de dispositivos micro-fluídicos de multicamadas com um nível de sofisticação comparável ao estado da arte. Foi desenvolvido o protótipo de um equipamento ótico para litografia por projeção que permite a fabricação de máscaras óticas com resolução de 5 m e oferece a possibilidade de litografia em escala de cinzas para gerar canais e estruturas com relevos arbitrários. Foram adicionalmente abordados três problemas de biofísica celular, para os quais foram propostos novos dispositivos para separação de células móveis de acordo às suas velocidades lineares, dispositivos para crescimento confinado de bactérias e dispositivos para manipulação da curvatura de membranas celulares. / The objective of this study is the development of a methodology for the fabrication of Lab On Chip systems, useful for the analysis of cellular processes, through the adaptation of technologies from microelectronics. All the steps involved with the fabrication of Lab on Chip system in Poly-Di-Methil-Siloxane (PDMS) were explored, developing protocols for mold fabrication, molding techniques and processes for oxygen plasma activation of PDMS for its bonding to different materials, achieving irreversible bonds that enable the integration with other technologies such as silicon microelectronics and green tape packaging. All this techniques constitute a methodology that allows the prototyping of multilayer microfluidic devices comparable with state of the art devices. It was developed the prototype of optical equipment for projection lithography capable of mask fabrication with 5 m resolution, and which offers also the capability of gray scale lithography for the generation of free form microchannels. Additionally three different problems in cellular biophysics where boarded, proposing new devices for the separation of motile cells according to their linear speeds in liquids, new devices for constrained bacterial growth and for curvature manipulation of cell membranes.

Nos últimos anos, as tecnologias de prototipagem rápida vem sendo amplamente utilizadas em aplicações na área de saúde, como ferramentas de auxílio na simulação e planejamento cirúrgico, bem como no projeto de implantes personalizados. Este trabalho fornece uma contribuição ao projeto destes implantes nas áreas de cranioplastia e buco-maxila. Baseado em sistemas CAD e nas tecnologias de prototipagem rápida são aplicadas diferentes alternativas para a geração adequada dos modelos médicos, ou biomodelos. Para aplicações em cranioplastias é proposto e implementado algoritmo para ajuste das bordas, permitindo dessa forma o correto ajuste do implante. Os resultados obtidos são aplicados diretamente em estudos de casos reais conduzindo a excelentes resultados e validando o procedimento proposto. / In the last years, the technologies of rapid prototyping have been widely used in medical applications, as supporting tools in the simulation and surgical planning, as well as in the design of customized implants. This work gives a contribution to the design of these implants in the cranioplasty and buco-maxila areas. Based on CAD systems and in the technologies of rapid prototyping, different alternatives are tested for the design of these modes, generically called as biomodels. For cranioplasty applications an algorithm is proposed and implemented for borders adjustment. The obtained results are directly applied in real case studies yielding to excellent results and validating the proposed procedure.