Letteratura scientifica selezionata sul tema "3D Line sets"
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Articoli di riviste sul tema "3D Line sets":
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Kamgar-Parsi, B., e B. Kamgar-Parsi. "Algorithms for matching 3d line sets". IEEE Transactions on Pattern Analysis and Machine Intelligence 26, n. 5 (maggio 2004): 582–93. http://dx.doi.org/10.1109/tpami.2004.1273930.
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Günther, Tobias, Christian Rössl e Holger Theisel. "Hierarchical opacity optimization for sets of 3D line fields". Computer Graphics Forum 33, n. 2 (maggio 2014): 507–16. http://dx.doi.org/10.1111/cgf.12336.
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Kanzler, Mathias, Marc Rautenhaus e Rudiger Westermann. "A Voxel-Based Rendering Pipeline for Large 3D Line Sets". IEEE Transactions on Visualization and Computer Graphics 25, n. 7 (1 luglio 2019): 2378–91. http://dx.doi.org/10.1109/tvcg.2018.2834372.
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Kamgar-Parsi, B., e B. Kamgar-Parsi. "Matching sets of 3D line segments with application to polygonal arc matching". IEEE Transactions on Pattern Analysis and Machine Intelligence 19, n. 10 (1997): 1090–99. http://dx.doi.org/10.1109/34.625109.
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Zhou, M., K. Y. Li, J. H. Wang, C. R. Li, G. E. Teng, L. Ma, H. H. Wu et al. "AUTOMATIC EXTRACTION OF POWER LINES FROM UAV LIDAR POINT CLOUDS USING A NOVEL SPATIAL FEATURE". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-2/W7 (16 settembre 2019): 227–34. http://dx.doi.org/10.5194/isprs-annals-iv-2-w7-227-2019.
Abstract (sommario):
<p><strong>Abstract.</strong> UAV LiDAR systems have unique advantage in acquiring 3D geo-information of the targets and the expenses are very reasonable; therefore, they are capable of security inspection of high-voltage power lines. There are already several methods for power line extraction from LiDAR point cloud data. However, the existing methods either introduce classification errors during point cloud filtering, or occasionally unable to detect multiple power lines in vertical arrangement. This paper proposes and implements an automatic power line extraction method based on 3D spatial features. Different from the existing power line extraction methods, the proposed method processes the LiDAR point cloud data vertically, therefore, the possible location of the power line in point cloud data can be predicted without filtering. Next, segmentation is conducted on candidates of power line using 3D region growing method. Then, linear point sets are extracted by linear discriminant method in this paper. Finally, power lines are extracted from the candidate linear point sets based on extension and direction features. The effectiveness and feasibility of the proposed method were verified by real data of UAV LiDAR point cloud data in Sichuan, China. The average correct extraction rate of power line points is 98.18%.</p>
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Kurz, Franz, Seyed Azimi, Chun-Yu Sheu e Pablo d’Angelo. "Deep Learning Segmentation and 3D Reconstruction of Road Markings Using Multiview Aerial Imagery". ISPRS International Journal of Geo-Information 8, n. 1 (18 gennaio 2019): 47. http://dx.doi.org/10.3390/ijgi8010047.
Abstract (sommario):
The 3D information of road infrastructures is growing in importance with the development of autonomous driving. In this context, the exact 2D position of road markings as well as height information play an important role in, e.g., lane-accurate self-localization of autonomous vehicles. In this paper, the overall task is divided into an automatic segmentation followed by a refined 3D reconstruction. For the segmentation task, we applied a wavelet-enhanced fully convolutional network on multiview high-resolution aerial imagery. Based on the resulting 2D segments in the original images, we propose a successive workflow for the 3D reconstruction of road markings based on a least-squares line-fitting in multiview imagery. The 3D reconstruction exploits the line character of road markings with the aim to optimize the best 3D line location by minimizing the distance from its back projection to the detected 2D line in all the covering images. Results showed an improved IoU of the automatic road marking segmentation by exploiting the multiview character of the aerial images and a more accurate 3D reconstruction of the road surface compared to the semiglobal matching (SGM) algorithm. Further, the approach avoids the matching problem in non-textured image parts and is not limited to lines of finite length. In this paper, the approach is presented and validated on several aerial image data sets covering different scenarios like motorways and urban regions.
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Du, Xuan, Zong Bin Li e Guo Hui Zhang. "Optimization of Printed Circuit Board Assignment and Component Allocation in Assembly Line". Advanced Materials Research 97-101 (marzo 2010): 2455–58. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.2455.
Abstract (sommario):
The assembly optimization problem of multiple printed circuit board (PCB) tasks is analyzed, and an optimal model is formulated to balance the workload in decoupled PCB assembly line. Combined with polychromatic sets and genetic algorithm (GA), an integrated methodology is developed to solve the PCB assignment and component allocation simultaneously. Based on polychromatic sets theory, a 3D numerical contour matrix is presented to describe the characters of PCB, component and machine and the constraint of machine and process, and a constraint model is formulated. Constraint model guarantees that GA searches in the available solution space and simplify the calculation of fitness value and GA operation. Computational results indicate that the approach presented in this paper is useful and effective.
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Zhao, Weizhao, Myron D. Ginsberg e David W. Smith. "Three-Dimensional Quantitative Autoradiography by Disparity Analysis: Theory and Application to Image Averaging of Local Cerebral Glucose Utilization". Journal of Cerebral Blood Flow & Metabolism 15, n. 4 (luglio 1995): 552–65. http://dx.doi.org/10.1038/jcbfm.1995.69.
Abstract (sommario):
Traditional autoradiographic image analysis has been restricted to the two-dimensional assessment of local cerebral glucose utilization (LCMRglc) or blood flow in individual brains. It is advantageous, however, to generate an entire three-dimensional (3D) data set and to develop the ability to map replicate images derived from multiple studies into the same 3D space, so as to generate average and standard deviation images for the entire series. We have developed a novel method, termed “disparity analysis,” for the alignment and mapping of autoradiographic images. We present the theory of this method, which is based upon a linear affine model, to analyze point-to-point disparities in two images. The method is a direct one that estimates scaling, translation, and rotation parameters simultaneously. Disparity analysis is general and flexible and deals well with damaged or asymmetric sections. We applied this method to study LCMRglc in nine awake male Wistar rats by the [14C]2-deoxyglucose method. Brains were physically aligned in the anteroposterior axis and were sectioned subserially at 100-μm intervals. For each brain, coronal sections were aligned by disparity analysis. The nine brains were then registered in the z-axis with respect to a common coronal reference level (bregma + 0.7 mm). Eight of the nine brains were mapped into the remaining brain, which was designated the “template,” and aggregate 3D data sets were generated of the mean and standard deviation for the entire series. The averaged images retained the major anatomic features apparent in individual brains but with some defocusing. Internal anatomic features of the averaged brain were smooth, continuous, and readily identifiable on sections through the 3D stack. The fidelity of the internal architecture of the averaged brain was compared with that of individual brains by analysis of line scans at four representative levels. Line scan comparisons between corresponding sections and their template showed a high degree of correlation, as did similar comparisons performed on entire sections. Fourier analysis of line scan data showed retention of low-frequency information with the expected attenuation of high-frequency components produced by averaging. Region-of-interest (ROI) analysis of the averaged brain yielded LCMRglc values virtually identical to those derived from measurements and subsequent averaging of data from individual brains. In summary, 3D reconstruction of averaged autoradiographic image data by disparity analysis is a feasible approach, which vastly simplifies ROI analysis, facilitates the assessment of hemodynamic or metabolic patterns in three dimensions, permits the computation of threshold-defined volumes of interest on averaged 3D data sets, makes possible atlas-based ROI strategies, and importantly provides the capability of generating 3D image data sets derived from arithmetic manipulations on two or more primary data sets (e.g., percent difference or ratio images).
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Lin, Li-Chieh J., Ray Y. Chuang, Chih-Heng Lu, Kuo-En Ching e Chien-Liang Chen. "Derivation of 3D Coseismic Displacement Field from Integrated Azimuth and LOS Displacements for the 2018 Hualien Earthquake". Remote Sensing 16, n. 7 (27 marzo 2024): 1159. http://dx.doi.org/10.3390/rs16071159.
Abstract (sommario):
A 3D surface deformation field for an earthquake can aid in understanding fault behaviors and earthquake mechanisms. However, SAR-based 3D surface deformation estimates are often limited by insufficient observations and hampered by various error sources. In this study, we demonstrate the derivation of a 3D coseismic displacement field from different InSAR processing algorithms. The azimuth displacements from Multiple Aperture Interferometry (MAI) and Pixel Offset Tracking (POT) were integrated to ensure reliable displacements at low coherent areas. The 3D displacement field was inverted pixel-by-pixel by Line-of-Sight (LOS) displacement and integrated azimuth displacement. The results showed that MAI and POT could compensate for the weaknesses of each algorithm. Also, pixels with less than three sets of observations showed higher noise levels. Such noisy pixels were removed by a denoising criterion proposed herein. For the vertical direction, the proportion of pixels inverted with two sets of azimuth and one set of LOS displacements was 26.1%. After denoising, the proportion dropped to 2.4% due to the insufficiency of LOS displacements. This shows that the viewing angle influences the overall performance of 3D surface displacement inversion. Implementing various displacement vectors should reduce such limitations.
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An, Su-Yong, Lae-Kyoung Lee e Se-Young Oh. "Line segment-based fast 3D plane extraction using nodding 2D laser rangefinder". Robotica 33, n. 08 (1 maggio 2014): 1751–74. http://dx.doi.org/10.1017/s0263574714000927.
Abstract (sommario):
SUMMARYThree-dimensional (3D) data processing has applications in solving complex tasks such as object recognition, environment modeling, and robotic mapping and localization. Because using raw 3D data without preprocessing is very time-consuming, extraction of geometric features that describe the environment concisely is essential. In this sense, a plane can be a suitable geometric feature due to its simplicity of extraction and the abundance in indoor environments. This paper presents an online incremental plane extraction method using line segments for indoor environments. Our data collection system is based on a “nodding” laser scanner, so we exploit the incremental nature of its data acquisition in which physical rotation and 3D data processing are conducted in parallel. Line segments defined by two end points become supporting elements that comprise a plane, so a large proportion of scan points can be ignored once the line segments are extracted from each scan slice. This elimination of points reduces the algorithm complexity and computation time. Experiments with the tens of complete scan data sets which were acquired from a typical indoor environment demonstrated that our method was at least three times faster than the state-of-the-art methods.
Tesi sul tema "3D Line sets":
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Schertzer, Jérémie. "Exploiting modern GPUs architecture for real-time rendering of massive line sets". Electronic Thesis or Diss., Institut polytechnique de Paris, 2022. http://www.theses.fr/2022IPPAT037.
Abstract (sommario):
Dans cette thèse, nous considérons des grands ensembles de lignes générés à partir de tractogrammes cérébraux. Ils décrivent des connexions neuronales représentées par des millions de fibres poly-lignes, comptant des milliards de segments. Grâce au mesh shader pipeline, nous construisons un moteur de rendu de tractogrammes aux performances surpassant l'état de l'art de deux ordres de grandeur.Nos performances proviennent des fiblets : une représentation compressée de blocs de segments. En combinant cohérence temporelle et dilatation morphologique du z-buffer, nous définissons un test d'occlusion rapide pour l'élimination de fiblets. Grâce à notre algorithme de décompression parallèle fortement optimisé, les fiblets survivants sont efficacement synthétisés en poly-lignes. Nous montrons également comment notre pipeline de fiblets accélère des fonctionnalités d'interactions avancées avec les tractogrammes.Pour le cas général du rendu des lignes, nous proposons la marche morphologique : une technique en espace écran qui rend des tubes d'épaisseur modifiable à partir des lignes fines rastérisées du G-buffer. En approximant un tube comme l'union de sphères densément réparties le long de ses axes, chaque sphère occupant chaque pixel est récupérée au moyen d'un filtre multi-passes de propagation de voisinage. Accéléré par le compute pipeline, nous atteignons des performances temps réel pour le rendu de lignes épaisses.Pour conclure notre travail, nous implémentons un prototype de réalité virtuelle combinant fiblets et marche morphologique. Il permet pour la première fois la visualisation immersive de grands tractogrammes constitués de fibres épaisses, ouvrant ainsi la voie à des perspectives diversesIn this thesis, we consider massive line sets generated from brain tractograms. They describe neural connections that are represented with millions of poly-line fibers, summing up to billions of segments. Thanks to the two-staged mesh shader pipeline, we build a tractogram renderer surpassing state-of-the-art performances by two orders of magnitude.Our performances come from fiblets: a compressed representation of segment blocks. By combining temporal coherence and morphological dilation on the z-buffer, we define a fast occlusion culling test for fiblets. Thanks to our heavily-optimized parallel decompression algorithm, surviving fiblets are swiftly synthesized to poly-lines. We also showcase how our fiblet pipeline speeds-up advanced tractogram interaction features.For the general case of line rendering, we propose morphological marching: a screen-space technique rendering custom-width tubes from the thin rasterized lines of the G-buffer. By approximating a tube as the union of spheres densely distributed along its axes, each sphere shading each pixel is retrieved relying on a multi-pass neighborhood propagation filter. Accelerated by the compute pipeline, we reach real-time performances for the rendering of depth-dependant wide lines.To conclude our work, we implement a virtual reality prototype combining fiblets and morphological marching. It makes possible for the first time the immersive visualization of huge tractograms with fast shading of thick fibers, thus paving the way for diverse perspectives
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Kanzler, Mathias [Verfasser], Rüdiger [Akademischer Betreuer] Westermann, Kai [Gutachter] Lawonn e Rüdiger [Gutachter] Westermann. "Interactive Visualization of Large 3D Line Sets / Mathias Kanzler ; Gutachter: Kai Lawonn, Rüdiger Westermann ; Betreuer: Rüdiger Westermann". München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1210163519/34.
Libri sul tema "3D Line sets":
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Ślusarski, Marek. Metody i modele oceny jakości danych przestrzennych. Publishing House of the University of Agriculture in Krakow, 2017. http://dx.doi.org/10.15576/978-83-66602-30-4.
Abstract (sommario):
The quality of data collected in official spatial databases is crucial in making strategic decisions as well as in the implementation of planning and design works. Awareness of the level of the quality of these data is also important for individual users of official spatial data. The author presents methods and models of description and evaluation of the quality of spatial data collected in public registers. Data describing the space in the highest degree of detail, which are collected in three databases: land and buildings registry (EGiB), geodetic registry of the land infrastructure network (GESUT) and in database of topographic objects (BDOT500) were analyzed. The results of the research concerned selected aspects of activities in terms of the spatial data quality. These activities include: the assessment of the accuracy of data collected in official spatial databases; determination of the uncertainty of the area of registry parcels, analysis of the risk of damage to the underground infrastructure network due to the quality of spatial data, construction of the quality model of data collected in official databases and visualization of the phenomenon of uncertainty in spatial data. The evaluation of the accuracy of data collected in official, large-scale spatial databases was based on a representative sample of data. The test sample was a set of deviations of coordinates with three variables dX, dY and Dl – deviations from the X and Y coordinates and the length of the point offset vector of the test sample in relation to its position recognized as a faultless. The compatibility of empirical data accuracy distributions with models (theoretical distributions of random variables) was investigated and also the accuracy of the spatial data has been assessed by means of the methods resistant to the outliers. In the process of determination of the accuracy of spatial data collected in public registers, the author’s solution was used – resistant method of the relative frequency. Weight functions, which modify (to varying degree) the sizes of the vectors Dl – the lengths of the points offset vector of the test sample in relation to their position recognized as a faultless were proposed. From the scope of the uncertainty of estimation of the area of registry parcels the impact of the errors of the geodetic network points was determined (points of reference and of the higher class networks) and the effect of the correlation between the coordinates of the same point on the accuracy of the determined plot area. The scope of the correction was determined (in EGiB database) of the plots area, calculated on the basis of re-measurements, performed using equivalent techniques (in terms of accuracy). The analysis of the risk of damage to the underground infrastructure network due to the low quality of spatial data is another research topic presented in the paper. Three main factors have been identified that influence the value of this risk: incompleteness of spatial data sets and insufficient accuracy of determination of the horizontal and vertical position of underground infrastructure. A method for estimation of the project risk has been developed (quantitative and qualitative) and the author’s risk estimation technique, based on the idea of fuzzy logic was proposed. Maps (2D and 3D) of the risk of damage to the underground infrastructure network were developed in the form of large-scale thematic maps, presenting the design risk in qualitative and quantitative form. The data quality model is a set of rules used to describe the quality of these data sets. The model that has been proposed defines a standardized approach for assessing and reporting the quality of EGiB, GESUT and BDOT500 spatial data bases. Quantitative and qualitative rules (automatic, office and field) of data sets control were defined. The minimum sample size and the number of eligible nonconformities in random samples were determined. The data quality elements were described using the following descriptors: range, measure, result, and type and unit of value. Data quality studies were performed according to the users needs. The values of impact weights were determined by the hierarchical analytical process method (AHP). The harmonization of conceptual models of EGiB, GESUT and BDOT500 databases with BDOT10k database was analysed too. It was found that the downloading and supplying of the information in BDOT10k creation and update processes from the analyzed registers are limited. An effective approach to providing spatial data sets users with information concerning data uncertainty are cartographic visualization techniques. Based on the author’s own experience and research works on the quality of official spatial database data examination, the set of methods for visualization of the uncertainty of data bases EGiB, GESUT and BDOT500 was defined. This set includes visualization techniques designed to present three types of uncertainty: location, attribute values and time. Uncertainty of the position was defined (for surface, line, and point objects) using several (three to five) visual variables. Uncertainty of attribute values and time uncertainty, describing (for example) completeness or timeliness of sets, are presented by means of three graphical variables. The research problems presented in the paper are of cognitive and application importance. They indicate on the possibility of effective evaluation of the quality of spatial data collected in public registers and may be an important element of the expert system.
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Read, John, e Peter Stacey. Guidelines for Open Pit Slope Design. CSIRO Publishing, 2009. http://dx.doi.org/10.1071/9780643101104.
Abstract (sommario):
Guidelines for Open Pit Slope Design is a comprehensive account of the open pit slope design process. Created as an outcome of the Large Open Pit (LOP) project, an international research and technology transfer project on rock slope stability in open pit mines, this book provides an up-to-date compendium of knowledge of the slope design processes that should be followed and the tools that are available to aid slope design practitioners.
This book links innovative mining geomechanics research into the strength of closely jointed rock masses with the most recent advances in numerical modelling, creating more effective ways for predicting rock slope stability and reliability in open pit mines. It sets out the key elements of slope design, the required levels of effort and the acceptance criteria that are needed to satisfy best practice with respect to pit slope investigation, design, implementation and performance monitoring.
Guidelines for Open Pit Slope Design comprises 14 chapters that directly follow the life of mine sequence from project commencement through to closure. It includes: information on gathering all of the field data that is required to create a 3D model of the geotechnical conditions at a mine site; how data is collated and used to design the walls of the open pit; how the design is implemented; up-to-date procedures for wall control and performance assessment, including limits blasting, scaling, slope support and slope monitoring; and how formal risk management procedures can be applied to each stage of the process.
This book will assist in meeting stakeholder requirements for pit slopes that are stable, in regards to safety, ore recovery and financial return, for the required life of the mine.
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van der Hoeven, Frank, e Alexander Wandl. Hotterdam: How space is making Rotterdam warmer, how this affects the health of its inhabitants, and what can be done about it. TU Delft Open, 2015. http://dx.doi.org/10.47982/bookrxiv.1.
Abstract (sommario):
Heat waves will occur in Rotterdam with greater frequency in the future. Those affected most will be the elderly – a group that is growing in size. In the light of the Paris heat wave of August 2003 and the one in Rotterdam in July 2006, mortality rates among the elderly in particular are likely to rise in the summer. METHOD The aim of the Hotterdam research project was to gain a better understanding of urban heat. The heat was measured and the surface energy balance modelled from that perspective. Social and physical features of the city we identified in detail with the help of satellite images, GIS and 3D models. We determined the links between urban heat/surface energy balance and the social/physical features of Rotterdam by multivariable regression analysis. The crucial elements of the heat problem were then clustered and illustrated on a social and a physical heat map. RESULTS The research project produced two heat maps, an atlas of underlying data and a set of adaptation measures which, when combined, will make the city of Rotterdam and its inhabitants more aware and less vulnerable to heat wave-related health effects. CONCLUSION In different ways, the pre-war districts of the city (North, South, and West) are warmer and more vulnerable to urban heat than are other areas of Rotterdam. The temperature readings that we carried out confirm these findings as far as outdoor temperatures are concerned. Indoor temperatures vary widely. Homes seem to have their particular dynamics, in which the house’s age plays a role. The above-average mortality of those aged 75 and over during the July 2006 heat wave in Rotterdam can be explained by a) the concentration of people in this age group, b) the age of the homes they live in, and c) the sum of sensible heat and ground heat flux. A diverse mix of impervious surfaces, surface water, foliage, building envelopes and shade make one area or district warmer than another. Adaptation measures are in the hands of residents, homeowners and the local council alike, and relate to changing behaviour, physical measures for homes, and urban design respectively.
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Arera-Rütenik, Tobias, Stefan Breitling, Rainer Drewello, Mona Hess e Gerhard Vinken, a cura di. The Centre for Heritage Conservation Studies and Technologies 2016-2018. University of Bamberg Press, 2021. http://dx.doi.org/10.20378/irb-49842.
Abstract (sommario):
The Centre for Heritage Conservation Studies and Technologies (KDWT) was founded in spring 2016 as a central research institute of the Otto Friedrich University Bamberg. The core tasks of the KDWT are the expansion of knowledge and technology transfer to non-university research in-stitutions, business and crafts, the expansion of technical excellence, the supplementation of the range of courses, the support in research, teaching, transfer and service in terms of content and technical equipment as well in the internationalisation of research. The centre is divided into four departments: Monument Preservation, Digital Heritage Technologies, Building Research and Res-toration Science and thus covers both the foundations in the humanities as well as engineering and scientific approaches. The first volume of the “Reports of the KDWT” series presents the technically diverse work of the first two and a half years since the KDWT was established in a format with colour illustrations. Four main chapters represent the four departments mentioned. First, the fundamental aims and focus of each subject are outlined. This is followed by individual presentations of the respective re-search projects, which also would like to bring the content closer to the non-expert reader, especially through the illustrations provided. For a better overview, basic information and thematically linked publications have been added to the projects. For example, the Monument Preservation department reports on various projects related to the theme, city and heritage conservation, addresses participatory heritage protection, emotions and heritage as well as a municipal monument plan for Bavaria, to name just a few. The digital heritage technologies outline projects in the area of 3D documentation. The building research area analy-ses large medieval buildings, develops concepts for building preservation and improves technical skills in building analysis. Finally, the area of restoration science explains the use of non-destructive methods of investigation and microanalysis based on international and local projects, be they Sin-ghalese temple sites, European cathedrals or medieval textiles from the Bamberg cathedral treasury. The aim of the project presentations is to clarify to what extent each sub-area represents the KDWT with extraordinary, professionally sound experience and expertise in teaching, research and above all in practice. In order to do justice to the extensive transfer, networking and research activities of the individual members, a fifth main chapter lists all individual services in alphabetical order until mid-2018.
Capitoli di libri sul tema "3D Line sets":
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Buchanan, Thomas. "Critical sets for 3D reconstruction using lines". In Computer Vision — ECCV'92, 730–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/3-540-55426-2_82.
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Liu, Yan, Hu Su, Yu Lei e Fan Zou. "Point Cloud Registration of Road Scene Based on SAC-IA and ICP Methods". In Proceeding of 2021 International Conference on Wireless Communications, Networking and Applications, 969–78. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2456-9_98.
Abstract (sommario):
AbstractRegistration of point cloud data obtained by vehicle-mounted LiDAR is necessary process to establish high-precision road scene 3D model automatically. This paper presents a set of multi-line LiDAR point cloud registration method in road scenarios. Firstly, the obtained original point cloud data are pre-processed according to the characteristics of multi-line LiDAR point cloud. Then an initial registration algorithm (SAC-IA) with sampling consistency based on fast point feature histogram (FPFH) is used to achieve the coarse registration for two frame point clouds. Lastly, ICP algorithm optimized by KD-tree is used for precise registration and global road point cloud model can be obtained by iterative registration. In order to verify the method, actual road point cloud data are collected. The experimental results show that the method is feasible and its registration accuracy can meet the requirements of road model.
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Mimra, Christopher, Vincent Krein, Racim Radjef, Bronwyn Fox e Peter Middendorf. "Detection of Gaps and Overlaps in Laser Line Triangulation Data of Dry Fibre Tape Layups Using Image Projection". In Advances in Automotive Production Technology – Towards Software-Defined Manufacturing and Resilient Supply Chains, 253–65. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27933-1_24.
Abstract (sommario):
AbstractA major cost driver in the production of carbon composite parts is the quality inspection, which to this day relies on manual investigation by a trained worker. Gaps and overlaps in the layups are to be detected because they are proven to be detrimental towards the mechanical properties of the final part. In recent works, laser line triangulation sensors have been applied to inspect layups of prepreg tapes and non-crimp fabric material. These sensors create a 3D point cloud of the specimens surface. This is then evaluated by conversion into a grey-scale image and a subsequent image processing algorithm. However, the most commonly used algorithms fail to differentiate between defects and small, acceptable irregularities, such as welding spots, slits and single fibres which stick out.The aim of this research is to develop a reliable evaluation method for scans of dry fibre tape layups. An overview over the different groups of algorithms is provided, image projection is selected and compared to algorithms which have been proven to work best on pre-pregs. While the common algorithms fail to classify a test set of dry fibre specimen, image projection can reach a true positive rate of 100% and a false positive rate of 19%. The proposed setup can be a centrepiece of a future in-line quality inspection system for dry fibre layups which has potential for a significant decrease of the manufacturing costs.
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Zappi, Victor, Dario Mazzanti e Florent Berthaut. "From the Lab to the Stage: Practical Considerations on Designing Performances with Immersive Virtual Musical Instruments". In Sonic Interactions in Virtual Environments, 383–424. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-04021-4_13.
Abstract (sommario):
AbstractImmersive virtual musical instruments (IVMIs) lie at the intersection between music technology and virtual reality. Being both digital musical instruments (DMIs) and elements of virtual environments (VEs), IVMIs have the potential to transport the musician into a world of imagination and unprecedented musical expression. But when the final aim is to perform live on stage, the employment of these technologies is anything but straightforward, for sharing the virtual musical experience with the audience gets quite arduous. In this chapter, we assess in detail the several technical and conceptual challenges linked to the composition of IVMI performances on stage, i.e., their scenography, providing a new critical perspective on IVMI performance and design. We first propose a set of dimensions meant to analyse IVMI scenographies, as well as to evaluate their compatibility with different instrument metaphors and performance rationales. Such dimensions are built from the specifics and constraints of DMIs and VEs; they include the level of immersion of musicians and spectators and provide an insight into the interaction techniques afforded by 3D user interfaces in the context of musical expression. We then analyse a number of existing IVMIs and stage setups, and finally suggest new ones, with the aim to facilitate the design of future immersive performances.
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Cipolla, Roberto, e Kwan-Yee K. Wong. "Shape from Profiles". In Images and Artefacts of the Ancient World. British Academy, 2005. http://dx.doi.org/10.5871/bacad/9780197262962.003.0014.
Abstract (sommario):
This chapter discusses profiles or outlines which are dominant features of images. Profiles can be extracted easily and reliably from the images and can provide information on the shape and motion of an object. Classical techniques for motion estimation and model reconstruction are highly dependent on point and line correspondences, hence they cannot be applied directly to profiles which are viewpoint dependent. The limitations of classical techniques paved the way for the creation of different sets of algorithms specific to profiles. In this chapter, the focus is on state-of-the-art algorithms for model reconstruction and model estimation from profiles. These new sets of algorithms are capable of reconstructing any kind of objects including smooth and textureless surfaces. They also render convincing 3D models, reinforcing the practicality of the algorithm.
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Murugan, Suriya, Sumithra M. G. e Logeswari Shanmugam. "Cognitive Mining for Exploratory Data Analytics Using Clustering Based on Particle Swarm Optimization". In Advances in Social Networking and Online Communities, 118–37. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-7522-1.ch007.
Abstract (sommario):
This chapter examines the exploratory data analytics that require statistical techniques on data sets which are in the form of object-attribute-time format and referred to as three-dimensional data sets. It is very difficult to cluster and hence a subspace clustering method is used. Existing algorithms like CATSeeker are not actionable and its 3D structure complicates the clustering process, hence they are inadequate to solve this clustering problem. To cluster these three-dimensional data sets, a new centroid-based concept is introduced in the proposed system called clustering using particle swarm optimization (CPSO). This CPSO framework can be applied to financial and stock domain datasets through the unique combination of (1) singular value decomposition (SVD), (2) particle swarm optimization (PSO), and (3) 3D frequent item set mining which results in efficient performance. CPSO framework prunes the entire search space to identify the significant subspaces and clusters the datasets based on optimal centroid value.
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Pizlo, Zygmunt, Yunfeng Li, Tadamasa Sawada e Robert M. Steinman. "A Second View Makes 3D Shape Perception Perfect". In Making a Machine That Sees Like Us, 144–71. Oxford University Press, 2014. http://dx.doi.org/10.1093/acprof:oso/9780199922543.003.0005.
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Fisher, Greg, John E. Wisneski e Rene M. Bakker. "Conclusion". In Strategy in 3D, 195–98. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190081478.003.0021.
Abstract (sommario):
This chapter returns to the high-level assumptions that motivated the writing of this book which include: (1) the field of strategy in the current day and age has become more relevant (not less); (2) strategic management should be practiced by more people (not fewer, and certainly not solely by those at the top of the organization; (3) strategy’s functional domain should be broadened (not narrowed); and (4) anyone with career ambition in the business world needs to become a strategist. It also discusses the option of combining multiple tools and offers advice on how this can be done. We note that there is no magic set of combinations that always works. Part of the learning experience in becoming a good strategist is learning when and how to apply certain tools in combination. As with many things in life, practice makes perfect. The chapter concludes with discussing the next frontier in strategic management.
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Boobalan, Parimala. "Emerging Trends in 3D Image Reconstruction and Modeling". In Recent Advances in 3D Imaging, Modeling, and Reconstruction, 129–42. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-5294-9.ch006.
Abstract (sommario):
In recent years, there is a demand for 3D content for computer graphics, communications, and virtual reality. 3D modelling is an emerging topic that is applied in so many real-world applications. The images are taken through camera at multiple angles and medical imaging techniques like CT scan and MRI are also used. From a set of images, intersection of these projection rays is considered to be the position for 3D point. This chapter discusses the construction of 3D images from multiple objects. Various approaches used for construction, triangulation method, challenges in building this model, and the application of 3D models are explained in this chapter.
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Slim, Ben Mimoun Mohamed, Garnier Marion e Poncin Ingrid. "Improving Consumer Performance and Perceived Service Quality in a New Type of Commercial Environment in 3D, Thanks to Embodied Virtual Sales Agents". In E-Marketing in Developed and Developing Countries, 233–45. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-3954-6.ch014.
Abstract (sommario):
Considering the development of interactive and rich media technologies on the Internet, the present research sets up the link between a 3D commercial website and embodied virtual agents. Thanks to an experiment on a 3D commercial website, the impact of a virtual salesperson is observed on consumer performance (effectiveness in product retrieving), immersion, and satisfaction. Results highlight the immersive capacity of such a commercial environment, the positive contribution of a virtual salesperson on consumer performance and the interest in a virtual salesperson’s help with online purchases. Theoretical and managerial implications are developed and discussed.
Atti di convegni sul tema "3D Line sets":
1
Rahman, M. T., e M. S. Alam. "Model based recognition using 3D line sets and multidimensional Hausdorff distance". In Optics & Photonics 2005, a cura di Andrew G. Tescher. SPIE, 2005. http://dx.doi.org/10.1117/12.618424.
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Chakrabarti, Partha, Subrata K. Chakrabarti, Adinarayana Mukkamala, Nagaraj Anavekar, Shen Qiang e M. Sri Krishna. "Design, Analysis and Verification of Moored Floating Caisson System". In ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/omae2004-51234.
Abstract (sommario):
Tacoma Narrows Constructors (TNC) is building a new suspension bridge in Tacoma, close to Seattle, Washington State, USA. The new bridge will be built just south of the existing bridge mounted on two caissons, referred to as East Caisson (Tacoma side) and West Caisson (Gig Harbor side). Each pier is about 80’ wide and 130’ long in plan. The mooring system for each caisson consists of two sets of mooring lines: lower and upper. Each set consists of 16 mooring lines. The lower 16 lines consist of anchors that form a radius of about 300 feet. The fairlead locations for these lower 16 lines are kept constant throughout the construction process. These 16 lines are hooked-up after the caisson is towed from the harbor and positioned at the site. For the upper 16 lines (except three lines on East Pier), the anchor locations form a radius of 600’. The fairlead locations for these upper 16 lines vary based on the draft. Due to the proximity of the proposed caissons to the existing piers and the varying bottom topography, considerable turbulence and vortex shedding is expected which will cause current induced dynamic forces on the caissons. This paper describes the design and analysis of this multi-line mooring system for Tacoma Narrows Bridge caissons, based on the construction sequence in the floating condition. The analysis involved optimizing the anchor locations and the line pretensions, determining the dynamic motions of the caissons, maximum line loads, and corresponding safety factors. The paper includes the hydrodynamic analysis for added mass, and damping, the methodology used for the nonlinear moored caisson analysis (MOTSIM), and the validation of the design tool with other similar models (e.g., StruCAD*3D). The results of the analysis and design are discussed.
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Bol, Eric, Curtis Doyle e M. Ramulu. "Process Parameter Effects on Melt Topology and Dimensional Deviation in Electron Beam Melted Ti-6Al-4V". In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-70698.
Abstract (sommario):
Abstract Industry is actively evaluating additive manufacturing (AM) for parts and assemblies, but many applications have strict requirements that manufacturing processes be stable and repeatable. This is currently a challenge for many operators of powder bed fusion (PBF) technologies where limited understanding of how the AM process parameters impact the dimensional deviation from the design and material quality. The experiment described in this paper employed an electron beam melting (EBM) Arcam A2X and Ti-6Al-4V powder to manufacture single lines of melted powder within the bed. This fundamental approach was designed to identify variation and inaccuracy at the micro scale that could provide lessons applicable to the macro scale. It is a subset of a broader ongoing effort intended to characterize the manufacturing repeatability of the EBM PBF process. The design of this experiment involved the placement of short line segments in various orientations within the build plane. Two different sets of process parameters were utilized to fabricate the CAD build geometry. Each line specimen was imaged and 3D scanned within the surrounding sintered powder to study the topology. Observations from the resulting measurements were correlated with the machine process parameters and log file data. The dimensional deviation of the melt - was characterized along with the minimum feature size. These findings provide valuable EBM design for additive manufacturing guidance to help improve quality and limit deviation in components produced for industrial applications.
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Kamgar-Parsi, B. "An open problem in matching sets of 3D lines". In Proceedings of the 2001 IEEE Computer Society Conference on Computer Vision and Pattern Recognition. CVPR 2001. IEEE, 2001. http://dx.doi.org/10.1109/cvpr.2001.990536.
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Kuhn, Michael, Kazuko Fuchi, Giorgio Bazzan, Michael J. Durstock, James J. Joo, Gregory W. Reich, Richard A. Vaia e Philip R. Buskohl. "Coupling of Geometric and Material Stiffening Mechanisms in Origami Design". In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/detc2016-60132.
Abstract (sommario):
Origami, the ancient art of paper folding, has recently garnered attention from the scientific community for its capacity for unique 2D – 3D shape change and programmable mechanical properties. Application areas of such properties include packaging, self-assembly, shock absorption and deployable structures. Recent studies have highlighted the role of the folded geometry to regulate the mechanical response of the origami structures, such as the increased compression stiffness of origami tubes or the tunable in-plane stiffness through select inversion of bi-stable fold vertices. In addition to geometric re-enforcement, the mechanical response of an origami structure can also be programmed through spatial patterning of the individual fold line stiffnesses. However, the coupling between the geometric and material stiffening design spaces for origami structures is poorly understood and design rules are needed to guide the use of material stiffening to enhance or mitigate a geometric stiffening effect. In this computational study, a modal analysis of a corrugated fold with varying degrees of pre-fold and different sets of fold stiffness distributions is evaluated to highlight the interaction between geometric and material stiffness mechanisms.
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Dong, Qingbing, Jing Wei, Yan Li e Lixin Xu. "A Numerical Model to Predict Dynamic Performance of Layered Gears at Starved Lubrication". In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-97276.
Abstract (sommario):
Abstract Gears of modern industry are required to have a good fatigue performance to transmit power and motion through the contact interfaces. Composite layered surfaces can effectively improve the damage resistance of gears and decrease the friction coefficients. However, improper surface modification may induce intensive stress concentrations at the joint interfaces of the strengthening layers and cause unexpected damages to the flanks. Furthermore, the amount of lubricant at the inlet may probably be insufficient to establish fully flooded condition, which may result in starvation and accelerate damages to the gear sets. In this study, a starved elastohydrodynamic lubrication (EHL) model in three-dimensional (3D) line contact for layered gears is developed. The potential energy method is employed to determine the load distribution along the action line. The loading force is assumed to be balanced by the lubrication pressure, which is derived by discretizing the dimensional Reynolds equation into a solvable matrix with the consideration of the enforced boundary conditions due to the inlet oil supply. The transient evolution of lubrication is investigated to evaluate the load-carrying capability of the lubricant film at various starvation conditions. The influence coefficients related to the displacements and stresses of the layered material system are determined with the assistance of the fast Fourier transform (FFT) algorithm, and the effects of the layer properties and the fabrication methods are evaluated. Such analysis may provide insightful information for the optimization of material systems with fabricated layers and engineering design of gears.
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Manuel Figueiredo, Carlos, e Sofia Machado Santos. "Virtual models of architectural spaces: methods for exploration, representation and interaction through narratives and visual grammars". In 13th International Conference on Applied Human Factors and Ergonomics (AHFE 2022). AHFE International, 2022. http://dx.doi.org/10.54941/ahfe1001935.
Abstract (sommario):
In this paper we aim to present a conceptual framework for virtual creation, exploration, and representation of architectural space. This framework will allow us to establish a method that will drive the viewer along a path, intended by the researcher, to experience, interact and get feedback of spaces in study, through linear or interactive narratives.Space virtual computational representation tools have evolved over the last decades and are now providing advanced new tools from gaming, AI and VR real-time complex fictional environments creation, depiction and interaction. From interior spaces to planetary systems, replicated or fictional, sets for all kinds of computer simulation models with immersive possibilities can be created and explored.In a linear visual narrative of a 3D animation the viewer is carried, without choice, by the flow of visual narrative storytelling, through several spaces, events, conclusions, expectations, premonitions, anticipations, empathy and characters and environments, fictional readings in dreamlike narratives, where reality and fantasy can be blended. In an interactive tale storytelling and script, the linearity would become in theoretically infinite lines of possible events and plots, with diverse endings, in which a narrative story line diverges in multiple plots.Having a set of formal parameterized elements within a grammatical lexicon that constitute and methodological approach to an architectural object in a study, it is intended to look at methods to experience, interact and get feedback of spaces in study, through visual multiple narratives, linear or interactive, being immersed or not. All these narrative approaches imply a script and visual grammars, storyline, and plot, where the player looks or travels through a fictional space, in a lived and experiential way.For conception and planning as for studying or research in the architectural field, this is an area of expertise to explore, as these new graphic computing tools can pursue new approaches, using several methods available to apply in each research, to provide analysis breakthroughs.
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Clemen, C. "Inverse 3D Camber-Line Calculation Tool INCA-3D". In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50253.
Abstract (sommario):
The modern aerodynamic design process of blades for commercial axial-flow compressors for aero-engines has to be fast but also accurate in terms of the blade and profile shaping. To achieve that, the three-dimensional flow effects, which have a significant impact on the optimum blade geometry, have to be considered in the early design phase. That requires fast software tools, which support the fully three-dimensional-design of compressor blades. This paper describes the software tool INCA-3D and its capabilities to calculate camber lines for compressor blade profiles inversely. INCA-3D is a Fortran coded software which runs on Unix and Windows operating systems and uses inviscid potential theory to calculate the camber lines of compressor rotor and stator blades based on the three-dimensional blade loading distribution. The input to the programme is the three-dimensional blade load distribution in terms of Δcp, the distribution of space-to-chord ratio, stagger angle (inlet angle), Mach number, chord length and leading edge shape (sweep and dihedral), which can be taken from throughflow analysis and 2D-blade-to-blade calculations. The output of INCA-3D are camber lines distributions along chord for 21 blade heights equally distributed over the annulus in a format which can be read in by a blade generation software. An INCA-3D run for a blade row takes, depending on the required accuracy, between 6 and 120 minutes and runs automatically. That means that a whole set of compressor blades can be generated within hours. The present paper shows the basic equations of the method, which INCA-3D is using and gives examples of the application of the software for different compressor test cases.
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Xuewu, Z. "Test Analysis of a 2D Seismic Survey With Finer CMP Interval". In Indonesian Petroleum Association - 46th Annual Convention & Exhibition 2022. Indonesian Petroleum Association, 2022. http://dx.doi.org/10.29118/ipa22-g-119.
Abstract (sommario):
Finer bin size or CMP interval normally means higher cost for a seismic survey, which makes sense for 3D projects because of very large equipment investment and difficulties of recording crew organization. However, the increase of active channels seems not to increase much cost for a conventional 2D seismic project in Indonesian jungle where the large portion of the cost is from line clearance, bridging, drilling and damage compensation. A test 2D line with 10 m receiver interval (RI), 60 m source interval (SI), 720 active channels and bunched geophone was acquired versus the production parameters of RI 30 m, SI 60 m, active channels 240 and arrayed geophone. The results demonstrate that flexible indoor arrays produce better effects than infield arrays where surface inconsistences exits. Data sets with RI of 20 m and 30 m with nominal full fold of 60 extracted respectively by picking one trace every two and one every three were processed. The comparisons of brute stacks with CMP interval 5 m, 10 m and 15 m demonstrate finer CMP interval can mitigate spatial aliasing and hence, improve denoising and S/N ratio. Instead of geophone array, the test data were also processed with nominal full folds of 120 and 180 by enlarging CMP intervals to be 10 m and 15 m. The comparisons indicate higher fold coverage can significantly improve seismic imaging with no negative impacts from geophone array. A trial with RI 10 m, CMP interval 15 m and SI 120 m was processed with nominal full fold 90. The purpose of such test is to seek a possible alternative of 2D geometry with dense receiver but sparse source for areas where the number of source holes is desired to be less. This paper intends to discuss ways for 2D seismic surveys cost-efficient and environmentally-friendly.
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Oosterhuis, Kas, e Arwin Hidding. "Participator, A Participatory Urban Design Instrument". In International Conference on the 4th Game Set and Match (GSM4Q-2019). Qatar University Press, 2019. http://dx.doi.org/10.29117/gsm4q.2019.0008.
Abstract (sommario):
A point cloud of reference points forms the programmable basis of a new method of urban and architectural modeling. Points in space from the smallest identifiable units that are informed to communicate with each other to form complex data structures. The data are visualized as spatial voxels [3d pixels] as to represent spaces and volumes that maintain their mutual relationships under varying circumstances. The subsequent steps in the development from point cloud to the multimodal urban strategy are driven by variable local and global parameters. Step by step new and more detailed actors are introduced in the serious design game. Values feeding the voxel units may be fixed, variables based on experience, or randomly generated. The target value may be fixed or kept open. Using lines or curves and groups of points from the original large along the X, Y and Z-axes organized crystalline set of points are selected to form the shape of actual working space. The concept of radical multimodality at the level of the smallest grain requires that at each stage in the design game individual units are addressed as to adopt a unique function during a unique amount of time. Each unit may be a home, a workplace, a workshop, a shop, a lounge area, a school, a garden or just an empty voxel anytime and anywhere in the selected working space. The concept of multimodality [MANIC, K Oosterhuis, 2018] is taken to its extreme as to stimulate the development of diversity over time and in its spatial arrangement. The programmable framework for urban multimodality acknowledges the rise and shine of the new international citizen, who travels the world, lives nowhere and everywhere, inhabits places and spaces for ultrashort, shorter or longer periods of time, lives her/his life as a new nomad [New Babylon, Constant Nieuwenhuys, 1958]. The new nomad lives on her/his own or in groups of like-minded people, effectuated by setting preferences and choices being made via the ubiquitous multimodality app, which organizes the unfolding of her / his life. In the serious design game nomadic life is facilitated by real time activation of a complex set of programmable monads. Playing and further developing the design journey was executed in 4 workshop sessions with different professional stakeholders, architects, engineers, entrepreneurs and project developers.