När mörkret faller är det svenska samhället i behov av belysning   för att underlätta framkomligheten. Belysning har visats öka säkerheten genom   minskad utsatthet för rån, skadegörelse, våldtäkt och andra kriminella   gärningar. Ett problem som uppmärksammades av produktutvecklingsföretaget   inom byggarbetsplatssäkerhet Safety Solutions Jonsereds, var mörka och trånga   passager som uppkom kring arbetsplatsinhägnader i anslutning till   byggarbetsplatser.   Med   syftet att öka säkerheten för oskyddade trafikanter, ville Safety Solutions   Jonsereds konstruera ett belysningsfäste som möjliggör tillfällig montering   av gång- och cykelbanebelysning (GC-belysning) på arbetsplatsinhägnaden SafePassTM Zone System. Målet var att utveckla ett belysningsfäste som   uppfyllde de krav och önskemål som förväntades av marknaden och uppdragsgivaren Safety Solutions Jonsereds.   Dessutom var målet även att kunna presentera belysningsfästet genom en   produktbeskrivning och en prototyp av 3D-modell. Genom att följa de   fem projektfaserna från Johannesson et al. kunde önskat belysningsfäste utvecklas åt Safety   Solutions Jonsereds, för att öka säkerheten kring arbetsplatsinhägnader.  Det framtagna belysningsfästet utmärker sig genom sina   ergonomiska funktioner vilket bidrar till ett säkert och effektivt montage av   GC-belysning på arbetsplatsinhägnaden SafePassTM Zone System. Belysningsfästet fyller dessutom ett tomrum på   marknaden, samtidigt som den uppnår   marknadens kriterier och Safety Solutions Jonsereds värdegrund. Uthyrning av   belysningsfästet kan i framtiden bidra till ökad säkerhet för oskyddade   trafikanter och ökad lönsamhet för Safety Solutions Jonsereds.   Vidare   arbete med val av belysning, elsäkerhet och omfattande kostnadskalkyler krävs   innan belysningssystemet är färdigt. Om fästet ska användas på statligt   ägda vägar krävs det att hela systemet testas tillsammans enligt standarden   EN1317-2 samt uppfyller ställda kapacitets- och skaderiskklasser.

Idag sitter flera aktörer inom byggbranschen kvar i gamla mönster och arbetssätt på grund av tidsbrist, rädsla och främst kunskapsbrist om ny teknologi. Building Information Modeling (BIM) är ett datoriserat verktyg för byggsektorn som skapar en digital 3D-modell av ett byggnadsverk där all information i byggnadsverkets livscykel kan samlas i modellen. Detta öppnar upp fler möjligheter än vad arbete med traditionella 2D-ritningar gör och BIM kommer spela en stor roll i byggbranschen i framtiden.  Syftet med denna rapporten är att undersöka hur en implementering och eventuell övergång till BIM skulle kunna gå till hos ett byggentreprenadföretag, samt hur BIM påverkar de olika processerna i anbudsskedet hos företaget.  För att samla in relevant kunskap om ämnet har litteraturstudier utförts under hela arbetets gång. För datainsamling har kvalitativa semi-strukturerade intervjuer genomförts på byggentreprenadföretaget Wästbygg och mjukvaruåterförsäljaren Cadcraft. Observationer har även verkställts på Wästbygg för att få kännedom om företagets arbetssätt i dagsläget.  Att implementera ett nytt arbetssätt med BIM skulle bevisligen kräva engagemang och tålamod från företagets sida. Nationella standarder finns inte för BIM i dagsläget och detta bedöms som en svårighetsfaktor. Vitalt är därför att företaget beslutar en tydlig strategi och målbild på förhand, samt fördelar ansvarsroller kring BIM-implementeringen till en eller två anställda. Att påbörja implementeringen i anbudsskedet är ett förnuftigt beslut – anbudsskedet befinner sig tidigt i byggprocessen och lyckas man framgångsrikt realisera BIM här är möjligheterna bättre för en vidareutveckling av företagets BIM-arbete. Framgångsrikt nyttjande av BIM innebär en semi-automatiserad mängdavtagning och kalkylering, ett förenklat informationsutbyte i anbudsskedet, samt en enkel och snygg visualisering både för personal och kund. Detta bidrar till en smidig och mer precis anbudprocess som kommer stärka företagets konkurrenskraft på marknaden. / Many construction businesses are stuck in old work patterns and procedures due to lack of time, nervousness and foremost lack of knowledge of new technology. Building Information Modeling (BIM) is a computer-aided instrument for the building sector which creates a digital 3D-model of a construction where all the information in the lifecycle of the construction is stored in the model. This entails additional opportunities compared to traditional 2D-drawings and BIM is due to play a huge part in the construction businesses in the future.  The purpose of this study is to examine how an implementation of BIM would be realized at a construction company, and furthermore how BIM affects the different processes within the tender stage of the company.  To gather appropriate knowledge surrounding the subject a literature study has been ongoing during the entirety of the study. For the purpose of data gathering, qualitative semi-structured interviews has been performed on the construction company Wästbygg and the retail company Cadcraft. Observations has also been performed on Wästbygg to get acquaintance with their current work procedures.  To implement a new work procedure with BIM would prove to require engagement and patience from the company. National standards do not currently exist, and this makes the progression more challenging. It is therefore vital for the company to decide a well-defined strategy and goals, and furthermore hand out responsibility to one or two employees on the BIM-implementation. To commence the implementation in the tender stage is a wise decision, the tender stage acts early in the construction process and if a realization of BIM is successful here, the opportunities for further expansion with BIM in the company is more probable. Successful practise with BIM would contribute to a semi-automated quantity take-off and calculation, a simplified information exchange in the tender stage, and a comfortable and appealing visualization for both staff and customer. This contributes to a straightforward and more precise tender stage which will strengthen the company’s competitiveness.

Samhället är under ständig digitalisering där ny teknik utvecklas och effektiviseras dagligen. Detta gör det möjligt att använda teknik på ett annat sätt än tidigare möjligt, inte minst inom byggindustrin. Det traditionella arbetssättet med 2D-ritningar har utvecklats till 3D-modeller och begreppet BIM (byggnadsinformationsmodeller) har sakta börjat etablera sig inom den svenska anläggningsbranschen. Definitionen av BIM är dock fortfarande svårdefinierad och det finns många olika åsikter om vad akronymen egentligen innebär. BIM är ett arbetssätt som bygger på virtuell projektering med ett konstant informationsflöde mellan olika parter i ett projekt. För att uppnå effektiv kommunikation används en 3D-modell där all information samlas och uppdateras av projektets konsulter allt eftersom projektet fortgår. Detta medför att alla parter har tillgång till korrekt information vid rätt tid. Företaget har arbetat med BIM i några år nu och har sett stora fördelar där huvudfokus i dagsläget ligger på stora multidisciplinära projekt där flera olika teknikområden ska arbeta tillsammans. Inom företaget används BIM främst inom projekteringsfasen där de största användningsområdena är samordning, visualisering och kalkylering. Vid ett effektivt användande av BIM kan man både spara tid och pengar. Trots att BIM har många fördelar går implementeringen sakta framåt. Syftet med studien är att undersöka vilka hinder och möjligheter det finns för en ökad implementering av BIM i anläggningsprojekt. Studien har genomförts som en kvalitativ forskningsstudie där information från en litteraturstudie har analyserat och jämförts med information från en intervjustudie. Intervjustudien har genomförts med olika konsulter på företaget med mål att kartlägga deras syn på BIM och hur en ökad implementeringen skulle kunna ske. Studien visar att bilden av BIM har förändrats från 3D-modeller till ett helt nytt arbetssätt där de främsta användningsområdena anses vara informationsutbyte, kommunikation, samordning, visualisering, kollisionskontroller, beräkning av mänger och kalkyler. Trots många fördelar med BIM finns det även en osäkerhet kring en ökad implementering. Ett av hindren är att beställarna i dagsläget inte efterfrågar BIM i alla anläggningsprojekt och det blir då företagets egna beslut att genomföra BIM samt göra det lönsamt. I dagsläget är inte BIM nog effektiviserat för att användas i alla projekt, men vid en ordentlig satsning av företaget med nya standardiseringar och mallar kan arbetssättet bli lönsamt i större utsträckning då BIM har visat på stora fördelar.    Slutsatsen från studien är att BIM är ett paradigmskifte och framtidens arbetssätt. För att företaget ska kunna konkurrera om alla projekt på marknaden framöver krävs det att företaget ständigt utvecklas. Som man brukar uttrycka det: den som slutar utvecklas kommer tillslut att bli omsprungen. / Society is under constant digitization, where new technology is developed and streamlined daily. This makes it possible to use technology in different ways than before. The construction industry is no different. The traditional way of working with 2D-drawings has been developed into 3D-models and the concept of BIM (building information models) has slowly started to establish itself in the Swedish construction industry. However, the definition of BIM is still difficult to determine and there are many different opinions about what the acronym really means. BIM is a way of working that is based on virtual design and construction with a constant flow of information between the different parties in the project. To achieve effective communication, a 3D-model is used where all information is available and updated by the project parties as the project proceeds. This means that all parties have access to the current information regarding the project in real-time. The company has been working with BIM for a few years now, and has seen great benefits where the main focus currently lies on large multidisciplinary projects where several different technology areas work together. Within the company, BIM is used primarily in the design phase, where the largest areas of application are coordination, visualization and calculation. When using BIM effectively, you can save both time and money. Although BIM has many benefits, the implementation is progressing very slowly. The purpose of the study is to investigate the obstacles and opportunities for increased implementation of BIM in construction projects. The study has been conducted as a qualitative research study where information from literature has been analyzed and compared with information from interviews. The interview study has been carried out with various consultants at the company with the goal of mapping their experience of BIM, the use within the company and how an increased implementation could take place. The study shows that the image of BIM has changed from 3D-models to a completely new way of working where the main areas of use are considered to be information exchange, communication, coordination, visualization, collision checks and calculation of quantities. Despite many advantages with BIM, there is also an uncertainty surrounding an increased implementation. One obstacle to overcome is that clients not always request BIM in their various construction projects, and it will then be the company's own decision to implement BIM and make it profitable. At present, BIM is not efficient enough for use in all projects, but in the case of a proper investment by the company with focus on new standardizations and rules, the working method can be profitable to a greater extent as BIM has shown great advantages so far. The conclusion from the study is that BIM is a paradigm shift and the future way of working. In order for the company to be able to compete for all projects in the future, the company must constantly develop.

Orientador: Marcos Valério Ribeiro / Resumo: O dissilicato de lítio, Li2Si2O5, é um material vitrocerâmico muito utilizado na fabricação de próteses dentárias, possui grande destaque por ser biocompatível e devido suas propriedades estéticas, químicas e mecânicas, permite a confecção de próteses a partir da usinagem CAD/CAM (COMPUTER-AIDED DESIGN / COMPUTER-AIDED MANUFACTURING), com elevada precisão dimensional e a possibilidade de restauração imediata em pacientes. Os materiais comerciais são disponibilizados com estrutura Li2SiO3 (metassilicato de lítio) cujas características são: alta usinabilidade e baixa tenacidade à fratura. Após a usinagem das próteses, o material sofre tratamento térmico visando à conversão do Li2SiO3 em Li2Si2O5 (dissilicato de litio), fase de melhor tenacidade e excelente apelo estético. A compreensão desta transformação de fase, seus efeitos na usinabilidade e nas propriedades mecânicas é de interesse tecnológico e científico, pois o material será utilizado como prótese dentária após este processamento. Este trabalho visou à avaliação do Li2Si2O5 em relação as propriedades químicas, físicas e mecânicas quando submetido a diferentes tratamentos térmicos. Foram empregados métodos de caracterização por difração de raios X (DRX), microscopia eletrônica de varredura (MEV), massa específica aparente, além da determinação da dureza, tenacidade à fratura, constantes elásticas e resistência à flexão biaxial sob diferentes condições de tratamento térmico. Também foram analisados a distribuição de partí... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-05-23T17:30:49Z No. of bitstreams: 1 DIS_MAURICIO_TOMAZONI_PEIXOTO_COMPLETO.pdf: 977170 bytes, checksum: 550fe78287feca797929ac42cf3a7c9c (MD5) / Made available in DSpace on 2017-05-23T17:30:49Z (GMT). No. of bitstreams: 1 DIS_MAURICIO_TOMAZONI_PEIXOTO_COMPLETO.pdf: 977170 bytes, checksum: 550fe78287feca797929ac42cf3a7c9c (MD5) Previous issue date: 2016-12-13 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The increasing demand for aesthetic restorations, associated with the evolution of techniques and materials, allowed the preparation of prosthetic pieces of reduced thickness. The introduction of CAD / CAM technology has made accurate and fast restorations. However, the final color of the restoration remains the direct responsibility of the dentist, where a visual assessment of color can cause errors, while an instrumental color measurement has accurate readings. The objective of the study was to investigate the factors that may influence the final color and translucency of different veneers with different thicknesses made by CAD/CAM materials and different types of resin cements on a darkened substrate. The samples were made by copy biogeneric in the CEREC SW 4.2 system, after a sample calculation of the pilot project, 60 upper central incisors of the right side of color C3 of epoxy resin were selected in 12 groups of 5 elements, divided according to type of (Lava Ultimate HT and LT), facet thickness (0.3mm / 0.6mm / 1.0mm) and cement type (Relyx Ultimate and Relyx Veneer). After cementation, the samples were taken with the spectrophotometer at a value of ?E in 6 different times with a silicone guide on the tooth, which ensures that the color is uniform. The results showed a significant difference in the values of ?E in groups 1 and 4 (HT and LT of 0.3 mm) cemented with Relyx Ultimate, in groups 7 and 9 (HT of 0.3 mm and 1.0 mm), and in groups 10 And 12 (LT of 0.3mm and 1.0mm) cemented with Relyx Veneer. However, the results were not significant for the masking of the darkened substrate over time, however, significant differences in ?E values were. / A crescente demanda por restaura??es est?ticas, associada a evolu??o das t?cnicas e materiais, possibilitaram a confec??o de pe?as prot?ticas de espessuras reduzidas. A introdu??o da tecnologia CAD/CAM possibilitou a realiza??o de restaura??es precisas e exatas rapidamente. No entanto, a cor final da restaura??o continua sendo responsabilidade direta do dentista, onde uma avalia??o visual de cor pode ocasionar erros, enquanto uma medi??o de cor instrumental possui leituras precisas. O objetivo do estudo foi realizar uma investiga??o dos fatores que podem influenciar a cor final e translucidez de facetas com diferentes espessuras confeccionadas por materiais CAD/CAM e diferentes tipos de cimentos resinosos sobre um substrato escurecido. As amostras foram confeccionadas por c?pia biogen?rica no sistema CEREC SW 4.2, ap?s c?lculo amostral do projeto piloto, foram selecionados 60 incisivos centrais superiores do lado direito de cor C3 de resina ep?xi foram divididos em 12 grupos de 5 elementos, divididos de acordo com tipo de material (Lava Ultimate HT e LT), espessura da faceta (0,3mm/ 0,6mm/ 1,0mm) e tipo de cimento (Relyx Ultimate e Relyx Veneer). Ap?s a cimenta??o, realizou-se a tomada de cor das amostras com o espectrofot?metro pelo valor de ?E em 6 tempos distintos com uma guia de silicone sobre o dente, que garante que a tomada de cor seja uniforme. Os resultados mostraram diferen?a significativa nos valores de ?E nos grupos 1 e 4 (HT e LT de 0,3mm) cimentados com Relyx Ultimate, nos grupos 7 e 9 (HT de 0,3mm e 1,0mm), e nos grupos 10 e 12 (LT de 0,3mm e 1,0mm) cimentados com Relyx Veneer. Entretanto os resultados n?o foram significativos quanto ao mascaramento do substrato escurecido ao longo do tempo, entretanto, foram observadas diferen?as significativas nos valores de ?E ao longo do tempo em uma an?lise intra-grupos.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-26T14:49:22Z No. of bitstreams: 1 DIS_JONAS_PEREIRA_ANDRADE_PARCIAL.pdf: 141765 bytes, checksum: 99338991681873f9d3d7028d9e7cdfa9 (MD5) / Made available in DSpace on 2017-06-26T14:49:22Z (GMT). No. of bitstreams: 1 DIS_JONAS_PEREIRA_ANDRADE_PARCIAL.pdf: 141765 bytes, checksum: 99338991681873f9d3d7028d9e7cdfa9 (MD5) Previous issue date: 2017-01-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The aim of the study was to evaluate, in vitro, the fracture resistance of occlusal veneers, made by CAD/CAM, with Lava Ultimate, e.max CAD and Vita Enamic materials in thicknesses of 0.6 mm and 1.5 mm. Seventy third human sound molars were randomly divided into seven groups (n = 10) according to the variables material and thickness, with the sound teeth as control. The root of the teeth was embedded into a self-cured acrylic resin and the teeth were prepared to simulate advanced erosion of the occlusal surface. The occlusal veneers were made using CAD-CAM technology, being luted to the preparation with adhesive systems and resin cements. After storage in distilled water at 37 ?C for 24 h, the samples were submitted to mechanical cyclic loading (1 million cycles at 100 N load). Subsequently, the sound teeth and the samples with the occlusal veneers were submitted to the fracture resistance test in a universal testing machine with crosshead speed of 1 mm/min. The failures were classified as reparable and irreparable. According to two-way ANOVA, the interaction between material and thickness was significant (p=0.013). The highest fracture resistance was obtained for the e.max CAD in the thickness of 1.5 mm (4995 N), being statistically superior to the other groups (p <0.05). The lowest fracture resistance was obtained for Vita Enamic at 0.6 mm thickness (2973 N), not being significantly different from e.max CAD 0.6 mm (3067 N), Lava Ultimate 0.6 mm (3384 N), Vita Enamic 1.5 mm (3540 N) and Lava Ultimate 1.5 mm (3584 N) (p>0.05). According to one- way ANOVA, the fracture resistance of the sound teeth (3991 N) did not differ significantly from the teeth with occlusal veneers (p> 0.05). The failures were predominantly repairable, except for sound teeth and Lava Ultimate 1.5 mm. The Lava Ultimate, e.max CAD and Vita Enamic occlusal veneers, in the thicknesses of 0.6 mm and 1.5 mm, showed fracture resistance exceeding the maximum masticatory forces. / O objetivo do estudo foi avaliar, in vitro, a resist?ncia ? fratura de facetas oclusais, confeccionadas por CAD/CAM, com os materiais Lava Ultimate, e.max CAD e Vita Enamic nas espessuras de 0,6 mm e 1,5 mm. Setenta terceiros molares humanos h?gidos foram aleatoriamente divididos em sete grupos (n=10) de acordo com as vari?veis material e espessura, tendo os dentes h?gidos como controle. A raiz dos dentes foi inserida em resina acr?lica quimicamente ativada e os dentes receberam um preparo para simular eros?o avan?ada da superf?cie oclusal. As restaura??es oclusais foram confeccionadas por meio da tecnologia CAD-CAM, sendo cimentadas ao preparo com sistemas adesivos e cimentos resinosos. Ap?s armazenagem em ?gua destilada a 37 ?C por 24 h, as amostras foram submetidas ? ciclagem mec?nica (1 milh?o de ciclos com carga de 100 N). Na sequ?ncia, os dentes h?gidos e as amostras com as facetas oclusais foram submetidas ao ensaio de resist?ncia ? fratura em m?quina de ensaio universal com velocidade de 1 mm/min. As falhas foram classificadas em repar?veis e irrepar?veis. De acordo com ANOVA de duas vias, a intera??o entre material e espessura foi significativa (p=0,013). A maior resist?ncia ? fratura foi obtida para o e.max CAD na espessura de 1,5 mm (4995 N), sendo estatisticamente superior aos demais grupos (p<0,05). A menor resist?ncia ? fratura foi obtida para o Vita Enamic na espessura de 0,6 mm (2973 N), n?o diferindo estatisticamente do e.max CAD 0,6 mm (3067 N), Lava Ultimate 0,6 mm (3384 N), Vita Enamic 1,5 mm (3540 N) e Lava Ultimate 1,5 mm (3584 N) (p>0,05). De acordo com ANOVA de uma via, a resist?ncia ? fratura dos dentes h?gidos (3991 N) n?o diferiu estatisticamente dos dentes com facetas oclusais (p>0,05). As falhas foram predominantemente do tipo repar?vel, com exce??o dos dentes h?gidos e Lava Ultimate 1,5 mm. As facetas oclusais em Lava Ultimate, e.max CAD e Vita Enamic, nas espessuras de 0,6 mm e 1,5 mm, demonstraram resist?ncia ? fratura que excede as for?as mastigat?rias m?ximas.

Kan Yeuk Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Objectives --- p.2 / Chapter 1.3 --- Report Organization --- p.3 / Chapter 2. --- RETROSPECT OF NON-MANIFOLD SOLID MODELING --- p.5 / Chapter 2.1 --- Geometric Modeling --- p.5 / Chapter 2.2 --- Euclidean Space and Topological Space --- p.6 / Chapter 2.3 --- Domains of Solid and Non-Manifold Geometric Modeling --- p.8 / Chapter 2.3.1 --- r-set Domain --- p.8 / Chapter 2.3.2 --- Manifold Domain --- p.9 / Chapter 2.3.3 --- Adjacency Form of Topology --- p.11 / Chapter 2.3.4 --- Cell Complex --- p.13 / Chapter 2.4 --- Representation Schemes of Solid and Non-Manifold Geometric Modeling --- p.14 / Chapter 2.4.1 --- Spatial Decomposition --- p.14 / Chapter 2.4.2 --- Constructive Solid Geometry (CSG) --- p.15 / Chapter 2.4.3 --- Boundary Representations (B-rep) --- p.17 / Chapter 2.5 --- Summary --- p.20 / Chapter 3. --- BOOSTING UP THE SPEED OF BOOLEAN OPERATIONS --- p.21 / Chapter 3.1 --- Solid Modeling with Specialized Hardware --- p.22 / Chapter 3.1.1 --- Modeling with a 4x4 Determinant Processor --- p.22 / Chapter 3.1.2 --- Ray Casting Engine --- p.24 / Chapter 3.2 --- Solid Modeling with General Purposed Parallel Computer --- p.25 / Chapter 3.2.1 --- Modeling with Shared Memory Parallel Computer --- p.27 / Chapter 3.2.2 --- Modeling with SIMD Massively Parallel Computer --- p.27 / Chapter 3.2.3 --- Modeling with MIMD Distributed Memory Parallel Computer --- p.30 / Chapter 3.3 --- Summary --- p.33 / Chapter 4. --- OVERVIEW OF DECmpp 12000/Sx/8K --- p.34 / Chapter 4.1 --- System Architecture --- p.34 / Chapter 4.1.1 --- DECmpp Sx Front End --- p.34 / Chapter 4.1.2 --- DECmpp Sx Data Parallel Unit --- p.35 / Chapter 4.1.2.1 --- Array Control Unit --- p.35 / Chapter 4.1.2.2 --- Processor Element Array --- p.35 / Chapter 4.1.2.3 --- Processor Element Communication Mechanism --- p.36 / Chapter 4.2 --- DECmpp Sx Programming Language --- p.37 / Chapter 4.2.1 --- Variable Declarations --- p.37 / Chapter 4.2.2 --- Plural Pointers --- p.38 / Chapter 4.2.3 --- Processor Selection by Conditional Expressions --- p.39 / Chapter 4.2.4 --- Processor Element Communications --- p.39 / Chapter 4.3 --- Summary --- p.40 / Chapter 5. --- ARCHITECTURE OF THE NON-MANIFOLD GEOMETRIC MODELER --- p.41 / Chapter 6. --- SEQUENTIAL MODELER --- p.43 / Chapter 6.1 --- Sequential Half-Wedge structures (SHW) --- p.43 / Chapter 6.2 --- Incremental Topological Operators --- p.51 / Chapter 6.3 --- Sequential Boolean Operations --- p.58 / Chapter 6.3.1 --- Complementing the subtracted model --- p.59 / Chapter 6.3.2 --- Computing intersection of geometric entities --- p.59 / Chapter 6.3.3 --- Construction of sub-faces --- p.53 / Chapter 6.3.4 --- Extraction of resultant topological entities --- p.64 / Chapter 6.4 --- Summary --- p.67 / Chapter 7. --- PARALLEL MODELER --- p.68 / Chapter 7.1 --- Parallel Half-Wedge Structure (PHW) --- p.68 / Chapter 7.1.1 --- Pmodel structure --- p.69 / Chapter 7.1.1.1 --- Phwedge structure --- p.69 / Chapter 7.1.1.2 --- Psurface structure --- p.71 / Chapter 7.1.1.3 --- Pedge structure --- p.72 / Chapter 7.1.2 --- Pmav structure --- p.73 / Chapter 7.2 --- Parallel Boolean Operations --- p.74 / Chapter 7.2.1 --- Complementing the subtracted model --- p.75 / Chapter 7.2.2 --- Intersection computation --- p.79 / Chapter 7.2.2.1 --- Distributing geometric entities --- p.80 / Chapter 7.2.2.2 --- Vertex-Vertex intersection --- p.89 / Chapter 7.2.2.3 --- Vertex-Edge intersection --- p.89 / Chapter 7.2.2.4 --- Edge-Edge intersection --- p.89 / Chapter 7.2.2.5 --- Vertex-Face intersection --- p.90 / Chapter 7.2.2.6 --- Edge-Face intersection --- p.92 / Chapter 7.2.2.7 --- Face-Face intersection --- p.93 / Chapter 7.2.3 --- Constructing sub-faces --- p.98 / Chapter 7.2.4 --- Extraction and construction of resultant topological entities --- p.100 / Chapter 7.3 --- Summary --- p.106 / Chapter 8. --- THE PERFORMANCE OF PARALLEL HALF-WEDGE MODELER --- p.108 / Chapter 8.1 --- The performance of converting sequential to parallel structure --- p.111 / Chapter 8.2 --- The overall performance of parallel Boolean operations --- p.112 / Chapter 8.3 --- The percentage of execution time for individual stages of parallel Boolean operations --- p.119 / Chapter 8.4 --- The effect of inbalance loading to the performance of parallel Boolean operations --- p.121 / Chapter 8.5 --- Summary --- p.125 / Chapter 9. --- CONCLUSIONS AND SUGGESTIONS FOR FURTHER WORK --- p.126 / Chapter 9.1 --- Conclusions --- p.126 / Chapter 9.2 --- Suggestions for further work --- p.127 / APPENDIX / Chapter A. --- SEQUENTIAL HALF-WEDGE STRUCTURE --- p.A-1 / Chapter B. --- COMPUTATION SCHEME IN CHECKING A FACE LOCATING INSIDE THE FACES OF A SOLID --- p.A-3 / Chapter C. --- ALGORITHM IN FINDING A HALF-WEDGE WITH A DIRECTION CLOSEST FROM A REFERENCE HALF-WEDGE --- p.A-5 / Chapter D. --- PARALLEL HALF-WEDGE STRUCTURE --- p.A-7 / REFERENCES --- p.A-10

於參數化和特徵模型的變形中保持幾何特徵是CAD建模中一項新的挑戰。這篇論文提出了一個以限制為基礎去進行變形的系統。此系統結合了自由曲面和特徵模型建模的好處，而且容許更自由的工程設計。 / 本方法可分為三個主要步驟。以常用的變形技術去改變一個模型的形狀，包括自由變形及軸向變形，然後參數特徵會根據用戶的要求去分拆為一系列基本的限制，最後目標特徵將會以逐步增量的優化技術去重建。 / 這篇論文提出了一個逐步增量的方法為優化中提供導引。這個優化是於維持所有提供的限制下盡量減少變形後模型的改變。另外，於一組的限制中以一個基准為參考，能使本系統更有效的運行。最後，我們也會展示一些使用本系統以限制為基礎去進行變形的結果。 / To retain geometric features in the deformation of a parametric and feature-based model is a new challenge for CAD modeling. This thesis presents a constraints based deformation framework. This framework combines the advantage of free-form modeling with feature based modeling, and allows engineering design to be performed in a free-form manner. / The proposed method can be divided into three major steps. An object is deformed by common deformation techniques such as FFD and axial deformation. Parametric features are divided into systems of primitive constraints based on user specification. The targeting features are reconstructed by the use of incremental optimization technique. / An incremental constrained deformation is introduced. It is used to provide hints for the optimization. The optimization is to minimize the changes in the deformed model subjected to all the provided constraints. For a structural constraint specified with a group of constraints, it would be better to use a reference datum for all its component constraints. We show numerous results of constraints retained models using our framework. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Tang, Wing Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 84-86). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Chapter 1 --- INTRODUCTION --- p.3 / Chapter 1.1 --- Aims and Objectives --- p.4 / Chapter 1.2 --- Report Organization --- p.5 / Chapter 2 --- BACKGROUND AND LITERATURE REVIEW --- p.7 / Chapter 2.1 --- Mesh Editing Techniques --- p.7 / Chapter 2.1.1 --- Mesh Deformation Techniques --- p.7 / Chapter 2.1.2 --- Detail Preserving Techniques --- p.9 / Chapter 2.2 --- Optimization Techniques --- p.11 / Chapter 2.2.1 --- Optimization Techniques --- p.11 / Chapter 2.2.2 --- Linear Programming --- p.12 / Chapter 2.2.2.1 --- Simplex Method --- p.12 / Chapter 2.2.2.2 --- Interior Point Method --- p.12 / Chapter 2.2.2.2.1 --- Primal-Dual Interior Point Method --- p.13 / Chapter 2.2.3 --- Nonlinear Programming --- p.14 / Chapter 2.2.3.1 --- Sequential Quadratic Programming --- p.14 / Chapter 2.2.3.2 --- Reduced Gradient Methods --- p.14 / Chapter 2.2.3.3 --- Interior Point Methods --- p.15 / Chapter 2.2.4 --- Optimization Solver --- p.15 / Chapter 2.2.4.1 --- KNITRO --- p.16 / Chapter 3 --- SPECIFICATION OF CONSTRAINTS --- p.18 / Chapter 3.1 --- Constraints --- p.18 / Chapter 3.1.1 --- Constraints with Reference Points --- p.22 / Chapter 3.1.2 --- Constraints with Reference Variables --- p.24 / Chapter 3.1.3 --- Reference Vector Constraints --- p.26 / Chapter 3.1.4 --- Constraints with Reference Datum --- p.27 / Chapter 3.1.4.1 --- Planer Constraint with References --- p.28 / Chapter 3.1.4.2 --- Collinear Constraint with References --- p.29 / Chapter 3.1.4.3 --- Circular Constraint with References --- p.30 / Chapter 3.2 --- Redundant Constraints --- p.31 / Chapter 4 --- CONSTRAINED OPTIMZATION --- p.32 / Chapter 4.1 --- Objective Function --- p.32 / Chapter 4.2 --- Incremental Constrained Deformation --- p.39 / Chapter 4.3 --- The Scaling Problem --- p.43 / Chapter 5 --- CASE STUDIES --- p.44 / Chapter 5.1 --- Maintain Individual Engineering Features --- p.44 / Chapter 5.2 --- Maintain Pattern between Engineering Features --- p.49 / Chapter 5.3 --- Maintain Relationship between Engineering Features --- p.51 / Chapter 5.4 --- Implementation Issue --- p.66 / Chapter 6 --- TESTS AND RESULTS --- p.68 / Chapter 6.1 --- Constraints with References --- p.68 / Chapter 6.2 --- Level Of Detail --- p.71 / Chapter 6.3 --- Incremental Method --- p.73 / Chapter 6.4 --- Comparison --- p.76 / Chapter 7 --- FURTHER WORK AND CONCLUSIONS --- p.81 / Chapter 7.1 --- Recommendation for Further Work --- p.81 / Chapter 7.2 --- Conclusions --- p.82 / REFERENCES --- p.84

The automotive engineering process is characterized by a long and complex design process which starts with the first sketches in the preliminary design phase and proceeds to the final detailed CAD and physical models. In this process, every design phase includes different process steps and tasks which are closely interconnected with each other. Therefore the different design stages demand capable Computer Aided Design (CAD) systems which are able to handle the different kinds of design information created and manipulated in the process. Currently in automotive practice, parametric and associative (PA) CAD systems are widely applied in the product development process. Such systems allow design knowledge to be embedded in CAD models by means of rules and formulae. In addition, CAD parts and assemblies can be generated faster and easier by modification of design parameters and therefore there is a possibility to create different CAD model variants which are based on the same CAD model. The four key element of the following work are (a) to identify the problems during the design process with parametric and associative (PA) methods during a three year of study and also the analysis of the literature survey. Furthermore (b) in this study the author will develop and implement a newly developed PA design approach (PARAMASS) in a ―real‖ industrial context. Beside this the following work will (c) discuss the issues which are important during the implementation of the developed PA approach in an industrial surrounding. The last key element (d) is to develop an evaluation approach for the PARAMASS approach during the application in an industrial context. In this case the author will be able to do action research in the industry and get first hand information during the accomplishment of these key elements. This thesis presents the results of a research programme carried out using the design research methodology of Blessing and Chakrabarti, aimed at understanding the difficulties and challenges faced by designers in using PA CAD systems and then developing and evaluating an integrated approach to the creation of PA CAD models in an automotive power train design context. Firstly, this thesis presents a review of the state of the art in PA design methods and approaches and also reviews previous research on the development of methodologies for the construction of PA CAD models. It then presents results of a descriptive study of the use of PA CAD tools and methods in vehicle power train design in an automotive original equipment manufacturer and in companies in its supply chain using questionnaires, interviews, tests and other field studies with a number of practising engineers. This study identified a number of issues faced by designers in the use of PA CAD tools and allowed the requirements for improved methods for the use of PA CAD tools to be formulated and indicators identified for their evaluation. Based on the results of the descriptive study a new integrated parametric associative (PA) approach for the design process of power train components was created in a prescriptive study stage. The approach, called PARAMASS, allows designers to construct and modify models in a methodical way based on three main phases: a specification phase to prepare the relevant parameters and associative relationships, a structuring phase that allows part and assembly structures to be created and a modification phase in which the created parametric and associative information can be modified and changed. The method makes extensive use of predefined structures matrix approaches adapted from the Design Structure Matrix. The prescriptive study phase of the research was followed by a second descriptive study to evaluate and investigate in both a qualitative and quantitative way the changes achieved by the PARAMASS approach. The qualitative evaluation was based on the Goal Question Metric approach and showed that there are advantages related to the reusability aspects like learning, application and acceptance of the developed integrated approach. The quantitative evaluation was based on the Use Case approach and demonstrated good advantages in applying the developed approach, but dependent on the complexity of the created parts and assemblies.

OBJECTIVE: The purpose of this study is to evaluate the experimental properties of zirconia-based ceramics. METHODS: Zirconia bars were veneered to 2mm total thickness. Veneering-method groups included: 1.Hand-layered feldsparthic porcelain (VM=VitaVM9,Vident) and fluorapatite glass-ceramic (CR=IPSe.maxCeram,IvoclarVivadent); 2.Pressed feldspathic porcelain (PM=VitaPM9,Vident) and fluorapatite glass-ceramic (ZP=IPSe.maxZirPress,IvoclarVivadent); 3.CAD/CAM milled feldspathic ceramic (TF=VitablocsTriluxeForte,Vident) and lithium-disilicate glass-ceramic (CAD=IPSe.maxCAD,IvoclarVivadent). CAD/CAM veneers were either cemented with resin cements (P=Panavia21,KurarayDental), (R=RelyXUltimate,3M ESPE), (M=MultilinkAutomix,IvoclarVivadent) or fused with fusion glass-ceramic (C=CrystalConnect,IvoclarVivadent). A Three-point-bending test was performed. For group VM,PM,TF-M,TF-C,CAD-M,CAD-C, ten more bars were prepared and aged with cyclic loading and thermocycling before testing. Zirconia bars (PrettauZirconia,Zirkonzahn;inCorisTZI,Sirona;ZirluxFC,PentronCeramics) specimens were prepared and polished. The specimens were divided into 3 groups: control, self-glaze fired, and glazed groups. A Three-point bending test was performed. Veneered zirconia crowns were made. Feldspathic porcelain was applied to zirconia coping. Bevel cut on porcelain was made to simulate porcelain chipping. The crowns were then divided into 4 different groups according to repair materials including: 1.Conventional-resin composite (TetricEvoCeram,IvoclarVivadent) 2.Flowable-resin composite (G-aenialUniversalFlo,GCamerica) 3.Cemented CAD/CAM milled feldspathic ceramic (VitaTriluxForte,Vident) 4.Cemented CAD/CAM milled lithium-disilicate glass-ceramic (IPSe.maxCAD,IvoclarVivadent). Each crown underwent thermocycling. The test was performed by loading force on the center of repaired part to record load-to-failure. RESULTS: There were significant differences in the failure loads of non-aged bilayered veneer-zirconia bars. Aging experiment revealed a significant difference in failure load between non-aged and aged bars in groups VM and PM, but not in the groups with CAD/CAM milled veneers. There was significant influence of surface treatments on flexural strength of zirconia specimens. Post-hoc test showed that glazed group had significant lower flexural strength than other groups. Crowns repaired with CAD/CAM ceramics showed significant higher failure load than resin composite. Repairing with lithium-disilicate glass ceramic yielded the highest load-to-failure of the specimens. CONCLUSIONS: - Veneer materials, veneering methods, and cement materials have a significant effect on the failure load of bilayered veneer- zirconia. CAD/CAM veneer-zirconia is not susceptible to aging performed in this study. - Glazing decreased the flexural strength of high translucent zirconia. - Veneered zirconia crowns repaired with CAD/CAM ceramic materials have significantly higher load-to-failure than veneered crowns repaired with resin composite. / 2018-09-28T00:00:00Z