This report aims to covers the conduction of a final thesis project for the University of Skövde in collaboration with J.Design studio (Stockholm). The purpose of this project is applying and evaluating CAD and different tools related to the field of 3D CAD within design and product development phases. This has been achieved by the development of two pieces of furniture from a defined line of products stated by existing clients of J.Design. The initial phase of the project was knowing the design limitations from both clients and their stakeholders. Once these limitations were known, a pre-study phase where 3D CAD modelling was set as the key tool for the research was done. This research identified related tools with CAD that are applied during the development design phase. Starting the development of the two case studies, the user needs’ phase was the first step in the process, followed by a benchmarking study, an ergonomics study, and finally, setting these requirements into a requirement list. Then, the design development phase took place, covering initial sketches until the detailed final solutions. As a final step, the use of the identified tools was evaluated and analysed based on the experience from the two case studies of this thesis project. From this evaluation came the conclusion that these tools need to take part in the design phase in a certain moment depending on the level of development, and as the level of sophistication of the tool increases, the information and detail provided are also higher.

The creation of 3D models of bone from CT images has become popular for surgical planning, the design of implants, and educational purposes. Software is available to convert CT images into 3D models of bone, however, these can be expensive and technically taxing. The goal of this project was to create an open-source and easy-to-use methodology to create 3D models of bone and allow the user to interact with the model to extract desired regions. The method was first created in MATLAB and ported to Python. The CT images were imported into Python and the images were then binarized using a desired threshold determined by the user and based on Hounsfield Units (HU). A Canny edge detector was applied to the binarized images, this extracted the inner and outer surfaces of the bone. Edge points were assigned x, y, and z coordinates based on their pixel location, and the location of the slice in the stack of CT images to create a 3D point cloud. The application of a Delaunay tetrahedralization created a mesh object, the surface was extracted and saved as an STL file. An add-on in Blender was created to allow the user to select the CT images to import, set a threshold, create a 3D mesh model, draw an ROI on the model, and extract that region based on the desired thickness and create a new 3D object. The method was fully open-sourced so was inexpensive and was able to create models of a skull and allow the segmentation of portions of that mesh to create new objects. Future work needs to be conducted to improve the quality of the mesh, implement sampling to reduce the time to create the mesh, and add features that would benefit the end-user. / Thesis / Master of Applied Science (MASc) / The creation of 3D models of bone from CT images has become popular for education, surgical planning, and the design of implants. Software is available to convert CT images into 3D models but can be expensive and technically taxing. The purpose of this project was to develop a process to allow surgeons to create and interact with models from imaging data. This project applied a threshold to binarize a set of CT images, extracted the edges using a Canny Edge detector, and used the edge pixels to create a 3D point cloud. The 3D point cloud was then converted to a mesh object. A user interface was implemented that allowed the selection of portions of the model and a new 3D model to be created from the selection. The process can be improved by improving the quality of the mesh output and adding features to the user interface.

No description available.

In this thesis, 12 aerial photographs flights were taken over a small building in the municipality of Trosa, with a drone, or the correct name in this case is UAV (Unmanned Aerial Vehicle). Where the purpose was to create 3D models from the aerial images. UAV by model DJI Mavic Pro was used and controlled with smartphone apps like DroneDeploy and Pix4Dmapper. Different values ​​for flight and shooting parameters were tested to see how it affects the quality of the 3D model. The flight and photographing parameters that were investigated were the UAV's flight speed, flight altitude and overlap between the images. Each parameter was given a low and a high accuracy value based on what is recommended. Which results in that flight height was the parameter that had a decisive influence on the model's pixel resolution and pixel density. The resolution for a 3D model with a flying height of 25 meters was 0,828 cm / pixel. While overlap did not give a marginal difference in the model's pixel resolution and pixel density. However, there were clear differences between models with low and high overlap. The flightspeed could not be properly investigated as changes to the flightspeed of DroneDeploy did not match the flightspeed in reality.   Smartphone apps, DroneDeploy and Pix4Dcapture that handle the UAV in autonomous data collection, compared where flights with similar values ​​where used for flight and shooting parameters. Three flights were made in each app where all parameters had a low, recommended and high accuracy value. The model’s pixel resolution and pixel density were equivalent between the apps, so a questionnaire survey was conducted where the models with high accuracy were compared. Which results in that all preferred the model created with aerial photos from Pix4Dcapture where it was described as better structure and higher detail.   Two different software programs, Agisoft Photoscan and Pix4Dmapper that manage aerial images to create 3D models was compared to each other. Images from flights with DroneDeploy were used where all parameters had a low, recommended and high accuracy value. Which results in 3 models for each software. All models from Pix4Dmapper had a much higher pixel density. A model from each software with aerial images with high accuracy was compared in a questionnaire. There, all preferred the model created in Pix4Dmaps and described as being more accurate angle, size and clearer windows as well as keeping the original structure better. / I detta examensarbete genomfördes ett 12 flygfotograferingar över en mindre byggnad i Trosa kommun, m.h.a. en drönare, eller den korrekta benämningen i det här fallet är UAV (Unmanned Aerial Vehicle). Där ändamålet var att skapa 3D modeller från flygbilderna. UAV av modell DJI Mavic Pro användes och styrdes med smartphone appar som DroneDeploy och Pix4Dmapper. Olika värden för flyg- och fotograferingsparametrar testades för att se hur det påverkar 3D-modellens kvalitet. Det flyg- och fotograferingsparametrar som undersöktes var UAV:ns flyghastighet, flyghöjd samt överlappning mellan bilderna. Varje parameter fick ett lågt och ett högt noggrannhetsvärde utifrån vad som är rekommenderat. Vilket resultera i att flyghöjden var den parameter som hade en avgörande påverkan för modellens pixelupplösning och pixeltäthet. Upplösningen för en 3D modell med en flyghöjd på 25 meter var på 0,828 cm/pixel. Medan överlappning inte gav en marginell skillnad på modellens pixelupplösning och pixeltäthet. Däremot syntes tydliga skillnader mellan modeller med låg och hög överlappning. Flyghastigheten kunde inte undersökas korrekt då ändringar för flyghastigheten i DroneDeploy inte stämde överens med flyghastigheten i verkligheten. Smartphone apparna, DroneDeploy och Pix4Dcapture som hanterar UAV:n vid autonom datainsamling som jämfördes där flygningar med liknanden värden användas för flyg- och fotograferingsparametrar. Tre flygningar gjordes i varje app där alla parametrar hade en låg, rekommenderad och hög noggrannhetsgrad. Modellernas pixelupplösning och pixeltäthet var likvärdiga mellan apparna, så en enkätundersökning gjordes där modellerna med hög noggrannhetsgrad jämfördes. Vilket resultera i att samtliga föredrog modellen skapad med flygbilder från Pix4Dcapture där den beskrevs som bättre struktur och högre detaljrikedom. Två olika programvaror, Agisoft Photoscan och Pix4Dmapper som hanterar flygbilder för att skapa 3D modeller jämfördes. Bilder från flygningar med DroneDeploy användes där alla parametrar hade en låg, rekommenderad och hög noggrannhetsgrad. Vilket resultera i 3 modeller för varje programvara. Samtliga modeller från Pix4Dmapper hade en mycket högre pixeltäthet. En modell från varje programvara med flygbilder med hög noggrannhetsgrad jämfördes i en enkät. Där samtliga föredrog modellen skapad i Pix4Dmapper och beskrev den som mer korrekt vinkel, storlek och tydligare fönstren samt att den behöll den ursprungliga strukturen bättre.

Synthetic marine habitats such as artificial reefs (ARs) are deployed to offset marine habitat losses and aid conservation of marine communities, including species at risk. Though environmental benefit is often assumed, AR’s ability to support northern temperate marine fish communities has rarely been tested. The structural orientation and location of a reef can strongly influence biodiversity and productivity of faunal communities inhabiting it. For ARs, understanding how reef characteristics affect species and community composition are key in optimizing their use in conservation initiatives. I used ROV and sonar to survey threatened rockfish (Sebastes spp.) and other groundfish species associated with 18 ARs and natural reefs (NRs) along the northeast Pacific coastal shelf, along the coast of BC, Canada. In my second chapter, I investigate how ARs compare to NRs in achieving conservation objectives as measured by fish abundance and species richness. I found that community composition significantly differed between NRs and ARs. ARs had high variability in rockfish abundance, while NRs consistently supported intermediate rockfish abundances. Groundfish diversity was markedly greater on NRs. Depth and relief significantly explained variability in abundance and species richness. Interestingly, rockfish abundance was negatively associated with proximity to nearest rockfish conservation area. In my third chapter, I assess variation between AR fish communities on six reefs to better understand efficacy of meeting conservation objectives. I quantified structural characteristics of each reef using high-definition sonar data to create three-dimensional models and calculate measurements of reef structure. I also examined the effects of surrounding habitat associated with reef locations. I found that depth, conservation status, rugosity, and reef age significantly explained rockfish abundance. Groundfish species richness was significantly associated with conservation status, relief, reef size, and an interaction between depth and reef age. This research is a first step in proposing underlying mechanisms for differences between fish communities on ARs in BC, and which reef attributes facilitate successful contributions to conservation. Though ARs show promise in the conservation of some threatened species, the maintenance of diverse fish communities may depend on protection of heterogeneous natural reef communities. Given that a critical component of AR success is structure, using three-dimensional technologies can be used as a tool to understand species-habitat association on existing reefs and help predict the success of future reefs. / Graduate

Des catastrophes comme celles de Ghislenghien (Belgique), Ludwigshafen (Allemagne), ou Lyon (France), ont été attribuées à des travaux à proximité de réseaux de gaz. Bien que les canalisations soient une des méthodes les plus sures de transport pour les substances dangereuses, chaque année plusieurs cas d'accidents sont enregistrés en France. La plupart d'entre eux sont attribués à des travaux à proximité des réseaux et certains illustrent le manque de fiabilité des informations fournies. Pour prévenir de tels accidents qui impliquent les ouvriers et le public, les autorités françaises ont mis en place deux réglementations : DT-DICT : pour la sécurisation des réseaux à proximité d'excavation ; Multifluide : pour celle des réseaux dangereux lors d'événements aléatoires. Eviter de tels accidents nécessite d'acquérir et de contrôler des informations 3D concernant les différents réseaux urbains, et particulièrement ceux enterrés. Des stratégies de prévention doivent alors être adoptées. Voilà pourquoi travailler sur les réseaux et leur visualisation et la cartographie des risques, en prenant en compte le flou, est une recherche récente et importante. Les applications logicielles que je développe devraient aider les services publics et les entrepreneurs à se concentrer sur la prévention des événements dangereux grâce à des ensembles de données précises pour les utilisateurs, la définition d'un réseau de géomatique, mais aussi des méthodes telles que la triangulation, la modélisation par éléments, les calculs géométriques, l'intelligence artificielle, la réalité virtuelle. / Disasters like the ones that happened in Ghislenghien (Belgium), Ludwigshafen (Germany), or Lyon (France), have been attributed to excavations in the vicinity of gas pipelines. Though pipes are one of the safest methods of transportation for conveying hazardous substances, each year many cases of damage to gas pipes are recorded in France. Most of them are due to works in the vicinity of the networks and some illustrate the lack of reliability of the provided information. Concessionaries have to take stock of the situation and to suggest areas of improvement, so that everyone could benefit from networks becoming safer.To prevent such accidents which involve workers and the public, French authorities enforce two regulations: DT / DICT: reform of the network no-damage by securing the excavations, Multifluide: reform which is interested in securing networks of hazardous events.So, to avoid such accidents or other problems, it is necessary to acquire and control the 3D information concerning the different city networks, especially buried ones.Preventive strategies have to be adopted. That’s why working on the networks and their visualization and risk cartography, taking the blur into account, is a recent and appropriate research. The software applications I develop should help the utility and construction contractors and focus on the prevention of hazardous events thanks to accurate data sets for users and consumers, the definition of a geomatics network but also some methods such as triangulation methods, element modeling, geometrical calculations, Artificial Intelligence, Virtual Reality.

No description available.

A relatively new fracture toughness testing method called Straight Notched Disc Bending (SNDB) was used before for fracture testing of Ankara Andesite and Afyon Marble cores. In this work to investigate the applicability of the new method to other rock types. With a preliminary notch of 10 mm, straight notched disc type specimens with a diameter of 75 mm were loaded by three-point bending loads. Investigation of effect of specimen height on the stress intensity factor and fracture toughness was carried out. Specimen heights (B) between 18 &ndash / 67 mm were tried for andesite and marble cylindrical specimens. Loading span, that is span/radius (S/R) ratio was changed between 0.6 - 0.9 for andesite specimens. Stress intensity factor for specimens was computed with ABAQUS program. Stress intensity factor was found to increase with increasing specimen diameter for a fixed span/radius ratio. Stress intensity factor decreased with increasing specimen height. Changing span was found to have no significant effect on fracture toughness of andesite. Fracture toughness was significantly lower for specimens with smaller height. The suggested testing height interval for this type of specimens was between height/diameter ratios of 0.49 &ndash / 0.64. Results were compared to the results obtained by a well-known specimen geometry named semi-circular bend specimens (SCB) under three-point bending. SCB tests produced lower values for fracture toughness for both rock types. Fracture toughness was 0.99 MPa&amp / #8730 / m for Ankara Andesite and 0.70 MPa&amp / #8730 / m for Afyon Marble.

The deficiencies of traditional dendrometry mean improvements in methods of tree mensuration are necessary in order to obtain accurate tree metrics for applications such as resource appraisal, and biophysical and ecological modelling. This thesis tests the potential of SfM-MVS (Structure-fromMotion with Multi-View Stereo-photogrammetry) using the software package PhotoScan Professional, for accurately determining linear (2D) and volumetric (3D) tree metrics. SfM is a remote sensing technique, in which the 3D position of objects is calculated from a series of photographs, resulting in a 3D point cloud model. Unlike other photogrammetric techniques, SfM requires no control points or camera calibration. The MVS component of model reconstruction generates a mesh surface based on the structure of the SfM point cloud. The study was divided into two research components, for which two different groups of study trees were used: 1) 30 small, potted ‘nursery’ trees (mean height 2.98 m), for which exact measurements could be made and field settings could be modified, and; 2) 35 mature ‘landscape’ trees (mean height 8.6 m) located in parks and reserves in urban areas around the South Island, New Zealand, for which field settings could not be modified. The first component of research tested the ability of SfM-MVS to reconstruct spatially-accurate 3D models from which 2D (height, crown spread, crown depth, stem diameter) and 3D (volume) tree metrics could be estimated. Each of the 30 nursery trees was photographed and measured with traditional dendrometry to obtain ground truth values with which to evaluate against SfM-MVS estimates. The trees were destructively sampled by way of xylometry, in order to obtain true volume values. The RMSE for SfM-MVS estimates of linear tree metrics ranged between 2.6% and 20.7%, and between 12.3% and 47.5% for volumetric tree metrics. Tree stems were reconstructed very well though slender stems and branches were reconstructed poorly. The second component of research tested the ability of SfM-MVS to reconstruct spatially-accurate 3D models from which height and DBH could be estimated. Each of the 35 landscape trees, which varied in height and species, were photographed, and ground truth values were obtained to evaluate against SfM-MVS estimates. As well as this, each photoset was thinned to find the minimum number of images required to achieve total image alignment in PhotoScan and produce an SfM point cloud (minimum photoset), from which 2D metrics could be estimated. The height and DBH were estimated by SfM-MVS from the complete photosets with RMSE of 6.2% and 5.6% respectively. The height and DBH were estimated from the minimum photosets with RMSE of 9.3% and 7.4% respectively. The minimum number of images required to achieve total alignment was between 20 and 50. There does not appear to be a correlation between the minimum number of images required for alignment and the error in the estimates of height or DBH (R2 =0.001 and 0.09 respectively). Tree height does not appear to affect the minimum number of images required for image alignment (R 2 =0.08).

To date, studies into sex determination and gonadal development have focused on the regulatory mechanisms governing development of the male or female phenotype. However, the formation of the testis and ovary from the bipotential gonad also present a fascinating model of tissue organisation which has been largely overlooked. When seeking to understand tissue organisation during gonadal development, the formation of testis cords takes center stage. However, despite a growing understanding of the cellular events in testis development, a number of key questions about the formation of testis cords remain unanswered. Specifically, I aimed to investigate the role of cell migration in testis organization, and the structure and morphogenesis of testis cords in three dimensions. To address these aims experimentally, I investigated the early morphogenesis of testis cords and the dependence of cord formation on cell migration from the mesonephros. I found that virtually all of the migrating cells express endothelial markers, indicating that endothelial, not peritubular myoid cells underlie the dependence of cord formation on cell migration. Further, disruption of endothelial cell migration and vascular organisation using a blocking antibody to VE-cadherin, also disrupted the development of testis cords. These data reveal that migrating endothelial cells are required for testis cord formation, consistent with increasing evidence of a broader role for vasculature in establishing tissue architecture during organogenesis. To address the question of cord structure and morphogenesis, I developed and applied a novel fluorescence-based three-dimensional modeling approach to show that Sertoli cells coalesce into irregular groups surrounding germ cells, and that these groups are remodeled to form highly regular toroidal loops, joined by a flattened plexus at the dorsal side. This plexus is punctured by blood vessels as they ingress from the mesonephros, and contracts during maturation to form part of the rete testis. Variation in cord number and position demonstrates that cord establishment is not a stereotypic process. However, a tightly regulated modeling mechanism must contribute to uniformity on cord diameter and orientation as these parameters remain consistent across samples of the same age. These data clarify questions of cord structure and organisation, establish that cord formation is a variable process, and demonstrate novel structural features within the network of testis cords. Finally, to investigate an in vivo model where vascularisation and cord formation may be disrupted, I analysed gonads from embryos lacking Cited2. Consistent with a previous study, I found that testis development was delayed in Cited2-/- gonads, but found that despite the reported transcriptional recovery after the delay, testis vascular and cord structure was permanently disrupted. To investigate the defects in cord formation I assayed cell migration and found that migration was not disrupted in XY gonads, or mesonephroi lacking Cited2. However, ectopic cell migration was observed in the XX gonad in a dose-dependent response to loss of functional Cited2 alleles. Correspondingly, the female pathway was initially delayed but rallied for a late recovery, implicating Sf1 in the initiation of ovarian differentiation. These data underscore the fragility of the molecular control of sex determination as absence of Cited2 in the male permanently disrupts testis morphology, whereas in the female, promoters of the male pathway are not sufficiently suppressed. From these studies I construct an integrated model of testis cord formation and conclude that testis cord formation is a novel form of tubulogenesis. This morphogenesis is unique and offers insights into cell and tissue organisation, vascular interactions in organogenesis, and mechanisms of tube formation. Further study of cord formation is likely to lead to a broader understanding of tissue morphogenesis during development.