Thesis (M.Sc.)--York University, 2004. Graduate Programme in Earth and Space Science & Engineering. / Typescript. Includes bibliographical references (leaves 117-123). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11920

Orientador: Ruis Camargo Tokimatsu / Resumo: A modelagem tridimensional muito já contribuiu com a indústria do entretenimento e agora tem sido amplamente utilizada na manufatura e criação de novos produtos. A possibilidade de se ter um modelo de um produto a um preço menor e com uma maior rapidez tem feito essa técnica ser cada vez mais aceita em todas as áreas da engenharia. Quando já se tem um modelo real e deseja-se realizar alguma modificação, simulação ou mesmo replicar o produto, a engenharia reversa muito pode contribuir, pois permite a obtenção do modelo tridimensional a partir do objeto real. Os equipamentos de digitalização tridimensional têm um alto custo de investimento, mesmo os de baixa precisão. A comunidade de entusiastas de software e hardware livre busca também distribuir e popularizar o conhecimento compartilhando suas descobertas e contribuindo abertamente com outras iniciativas. Buscamos nesse projeto construir um scanner 3D utilizando software e hardware livre utilizando componentes de baixo custo e fácil aquisição, estabelecendo seus limites técnicos, estimulando assim a adoção de técnicas de engenharia reversa. O processo de calibragem, captura e pós tratamento da nuvem de pontos obtidas foi detalhado na construção de modelos para comparação de dimensões e levantamento de características da superfície do material. / Mestre

Submitted by Sandro Moreira (moreira.sandro@gmail.com) on 2017-01-18T18:23:17Z No. of bitstreams: 1 SandroMoreira-DissertacaoMestradoFinal.pdf: 12934831 bytes, checksum: a63cb94b201b877dc272a7bccad284bc (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-01-23T19:48:34Z (GMT) No. of bitstreams: 1 moreira_ss_me_ilha.pdf: 12934831 bytes, checksum: a63cb94b201b877dc272a7bccad284bc (MD5) / Made available in DSpace on 2017-01-23T19:48:34Z (GMT). No. of bitstreams: 1 moreira_ss_me_ilha.pdf: 12934831 bytes, checksum: a63cb94b201b877dc272a7bccad284bc (MD5) Previous issue date: 2016-12-06 / A modelagem tridimensional muito já contribuiu com a indústria do entretenimento e agora tem sido amplamente utilizada na manufatura e criação de novos produtos. A possibilidade de se ter um modelo de um produto a um preço menor e com uma maior rapidez tem feito essa técnica ser cada vez mais aceita em todas as áreas da engenharia. Quando já se tem um modelo real e deseja-se realizar alguma modificação, simulação ou mesmo replicar o produto, a engenharia reversa muito pode contribuir, pois permite a obtenção do modelo tridimensional a partir do objeto real. Os equipamentos de digitalização tridimensional têm um alto custo de investimento, mesmo os de baixa precisão. A comunidade de entusiastas de software e hardware livre busca também distribuir e popularizar o conhecimento compartilhando suas descobertas e contribuindo abertamente com outras iniciativas. Buscamos nesse projeto construir um scanner 3D utilizando software e hardware livre utilizando componentes de baixo custo e fácil aquisição, estabelecendo seus limites técnicos, estimulando assim a adoção de técnicas de engenharia reversa. O processo de calibragem, captura e pós tratamento da nuvem de pontos obtidas foi detalhado na construção de modelos para comparação de dimensões e levantamento de características da superfície do material. / The three-dimensional modeling has contributed much to the entertainment industry and has now been widely used in manufacturing and creating new products. The possibility of having a model of a product at a lower price and a higher speed have made this technique is increasingly accepted in all fields of engineering. When there is already a real model and you want to make any changes, simulation or even replicate the product, reverse engineering can greatly contribute, as it allows to obtain three-dimensional model from the real object. The three-dimensional scanning equipment have a high investment cost, even low accuracy. The community of enthusiasts of open source and open hardware also distribute and popularize knowledge sharing his findings and openly contribute to other initiatives. We seek in this study, build a scanner 3D using free software and hardware components using low-cost and easy acquisition, establishing its technical limits, stimulating the adoption of reverse engineering techniques. The calibration, capture and post-treatment process of the cloud of points obtained was detailed in the construction of models for comparison of dimensions and survey of surface characteristics of the material.

In this thesis, we investigate the stochastic three dimensional Navier-Stokes-∝ model and the stochastic three dimensional Leray-∝ model which arise in the modelling of turbulent flows of fluids. We prove the existence of probabilistic weak solutions for the stochastic three dimensional Navier-Stokes-∝ model. Our model contains nonlinear forcing terms which do not satisfy the Lipschitz conditions. We also discuss the uniqueness. The proof of the existence combines the Galerkin approximation and the compactness method. We also study the asymptotic behavior of weak solutions to the stochastic three dimensional Navier-Stokes-∝ model as ∝ approaches zero in the case of periodic box. Our result provides a new construction of the weak solutions for the stochastic three dimensional Navier-Stokes equations as approximations by sequences of solutions of the stochastic three dimensional Navier-Stokes-∝ model. Finally, we prove the existence and uniqueness of strong solution to the stochastic three dimensional Leray-∝ equations under appropriate conditions on the data. This is achieved by means of the Galerkin approximation combines with the weak convergence methods. We also study the asymptotic behavior of the strong solution as alpha goes to zero. We show that a sequence of strong solution converges in appropriate topologies to weak solutions of the stochastic three dimensional Navier-Stokes equations. All the results in this thesis are new and extend works done by several leading experts in both deterministic and stochastic models of fluid dynamics. / Thesis (PhD)--University of Pretoria, 2010. / Mathematics and Applied Mathematics / unrestricted

M. Tech. Civil Engineering / Asphalt mixes are commonly used for paving roads around the world. They consist of mainly bitumen and aggregate materials, which may differ depending on the type of asphalt mix. The shape properties of aggregate particles relevant for the performance of asphalt mixes include the form, angularity and surface texture. There are concerns about the standard test methods used to quantify the shape properties (i.e. angularity, surface roughness, flatness, elongation and sphericity) of aggregates used for road pavement design and construction. These test methods have been reported as time and labour intensive, and have several limitations including human error, lack of accuracy, and repeatability of test results. Although results obtained from these tests have been linked to performance, however these links are questionable. Recently, various researchers and practitioners have indicated that advanced and automated approaches such as imaging and laser scanning techniques would better quantify the shape and surface properties of aggregates. For instance, researchers at the Council for Scientific and Industrial Research (CSIR) found that a portable three-dimensional (3-D) laser scanning system can be used to accurately quantify the shape properties of aggregate particles that are relevant to the performance of asphalt mixes. The overall objective of this study was to use a 3-D laser scanning technique to quantify the shape properties of aggregate materials and relate them to performance of laboratory compacted asphalt mixes.

Rwanda experienced one of the most horrendous atrocities in our modern history in the summer of 1994 when a genocide occurred within the country, and in the aftermath the nation had to deal with this history and rebuild its society. This essay examines the reconciliation in post-genocide Rwanda with the aim of investigating potential power mechanisms during this process. The study researches the policies implemented by the government of Rwanda during this process and what effect they potentially can have on the reconciliation in the country. The focus is on the policy of National Unity and Reconciliation and two of the main instruments within this government policy, which are Gacaca and Ingando. The analytical framework for this study is Steven Lukes’ theory on three-dimensional power, which was applied as an analytical lens to examine the power exercise by the RPF government. The essay used an abductive approach to research the subject and a case study as the chosen method for the study. The results of the research confirms that there are several instances of power exercise, both within the two and three-dimensional concept of power as described by Lukes. Certain aspects of the RPF’s policies aimed at reconciliation can be seen as power exercise by the government and potentially be problematic for a successful reconciliation process.

No description available.

Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The investigation of reservoir sedimentation has become an important and valuable research topic in engineering practice. Sediment deposition in reservoirs can affect ood levels, drainage for agriculture land, pumpstation and hydropower operation and navigation. An extensive review of the technical literature pertaining to suspended sediment transports as well as deposited sediment ushing from reservoirs has shown that most studies on sediment are still based on empirical formulas and experimental work, despite the availability of sophisticated computers. This is because sediment transport and particularly sediment deposition and erosion are complex processes, that involve the interaction of many physical factors which are not easily modelled numerically. In addition, most of the existing three-dimensional numerical models are not coupled hydrodynamic and sediment transport models. They first simulate the velocity field and water depth and then the concentration and bed change are calculated. Furthermore, they are not fully three-dimensional models for using layer-averaged approaches in conjunction with Saint-Venant equations. The key objective of the present research was to develop a coupled fully three-dimensional (3D) numerical model based on Navier-Stokes equations which includes both the sediment transport component and hydrodynamic parameters. In this regard, a physical model was set up in a laboratory ume in order to investigate the bottom outlet sediment ushing under pressure in a controlled environment. The proposed coupled fully 3D numerical model was used to simulate the experimental tests. Results from these simulations were in good agreement with the measurements. The geometric features of the scour hole (temporal and spatial hole development) upstream of the bottom outlet were reasonably well predicted compared to the experimental data. Furthermore, the velocity field upstream of the bottom outlet was in good agreement with measurements. The proposed numerical model can be considered reliable provided that the model is correctly set up to reflect the condition of a particular case study. Finally, the coupled fully 3D numerical model for turbulent suspended sediment transport in reservoirs was validated against a range of typical reservoir sediment transport and deposition laboratory flume cases. The proposed suspended sediment transport model successfully predicted both sediment deposition and entrainment processes and therefore, it can be used for turbulent suspended sediment transport assessments in reservoirs. / AFRIKAANSE OPSOMMING: Die ondersoek van damtoeslikking het 'n belangrike navorsing onderwerp in ingenieurswese praktyk geword. Sedimentdeponering in damme kan vloed vlakke, dreinering van landbo grond sowel as pompstasie en hidrokrag werking en navigasie benvloed. 'n Omvattende ontleding van die tegniese literatuur met betrekking tot gesuspendeerde sedimentvervoer asook die spoel van gedeponeerde sediment uit reservoirs het getoon dat die meeste studies oor sediment steeds op empiriese formules en eksperimentele werk gebaseer is, ten spyte van die beskikbaarheid van gesofistikeerde rekenaars. Dit is omdat sedimentvervoer en veral sedimentafsetting en -erosie komplekse prosesse is, wat die interaksie van baie fisiese faktore behels en nie moeiteloos numeries gemodelleer kan word nie. Daarbenewens, in die meeste van die bestaande drie -dimensionele numeriese modelle is die hidrodinamika en sedimentvervoer modelle nie gekoppel nie. Die numeriese modelle simuleer eerstens die snelheid veld en waterdiepte en dan word die sedimentkonsentrasie en bedverandering bereken. Verder is die bestaande modelle nie ten volle driedimensioneel nie, en gebruik laag-gemiddelde benadering in samewerking met Saint- Venant vergelykings. Die hoofdoelwit van die huidige navorsing was om 'n gekoppelde volle drie -dimensionele (3D) numeriese model gebaseer op Navier -Stokes-vergelykings wat beide die sediment vervoer komponent en hidrodinamiese parameters insluit, te ontwikkel. In hierdie verband is 'n fisiese model opgestel in 'n laboratorium kanaal om die bodem uitlaat spoel van sediment onder druk in 'n beheerde omgewing te ondersoek. Die voorgestelde gekoppelde 3D numeriese model is gebruik om die eksperimentele toetse na te boots. Resultate van hierdie simulasies het goed ooreengestem met die metings. Die geometriese eienskappe van die erosie gat (tyd en ruimtelike gatontwikkeling) stroomop van die bodemuitlaat was redelik goed voorspel vergeleke met die eksperimentele data. Verder is die snelheid veld stroomop van die bodem uitlaat ook goed voorspel. Die voorgestelde numeriese model kan beskou word as betroubaar met die wete dat die model korrek opgestel is om die toestand van 'n bepaalde gevallestudie te weerspiel. Ten slotte, is n gekoppelde 3D numeriese model vir turbulente gesuspendeerde sediment vervoer in reservoirs ontwikkel en getoets teen 'n reeks laboratorium kanaal eksperimente. Die voorgestelde gesuspendeerde sediment vervoer model voorspel suksesvol beide die sediment afsetting- en erosieprosesse en daarom kan dit gebruik word vir die simulasie van turbulente gesuspendeerde sediment vervoer in damme.

published_or_final_version / abstract / Computer Science / Master / Master of Philosophy

published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy