scholarly journals Direct 3D model extraction method for color volume images

2021 ◽  
Vol 29 ◽  
pp. 133-140
Author(s):  
Bin Liu ◽  
Shujun Liu ◽  
Guanning Shang ◽  
Yanjie Chen ◽  
Qifeng Wang ◽  
...  
Keyword(s):  
3D Model ◽  
Clinical Medicine ◽  
Three Dimensional ◽  
Laplacian Matrix ◽  
Segmentation Method ◽  
Human Organs ◽  
Model Segmentation ◽  
Treatment Objective ◽  
Organ Models ◽  
Different Parts

BACKGROUND: There is a great demand for the extraction of organ models from three-dimensional (3D) medical images in clinical medicine diagnosis and treatment. OBJECTIVE: We aimed to aid doctors in seeing the real shape of human organs more clearly and vividly. METHODS: The method uses the minimum eigenvectors of Laplacian matrix to automatically calculate a group of basic matting components that can properly define the volume image. These matting components can then be used to build foreground images with the help of a few user marks. RESULTS: We propose a direct 3D model segmentation method for volume images. This is a process of extracting foreground objects from volume images and estimating the opacity of the voxels covered by the objects. CONCLUSIONS: The results of segmentation experiments on different parts of human body prove the applicability of this method.

Automatic Brain Cancer Segmentation on PET Image

2020 ◽  
pp. 2150008
Author(s):  
Ching-Lin Wang ◽  
Chi-Shiang Chan ◽  
Wei-Jyun Wang ◽  
Yung-Kuan Chan ◽  
Meng-Hsiun Tsai ◽  
...  
Keyword(s):  
Brain Tumor ◽  
3D Model ◽  
Early Stage ◽  
Three Dimensional ◽  
Ground Truth ◽  
Emission Tomography ◽  
Segmentation Method ◽  
Brain Images ◽  
Positron Emission ◽  
Image Set

When treating a brain tumor, a doctor needs to know the site and the size of the tumor. Positron emission tomography (PET) can be effectively applied to diagnose such cancers based on the heightened glucose metabolism of early-stage cancer cells. The purpose of this research is to extract the regions of skull, brain tumor, and brain tissue from a series of PET brain images and then a three-dimensional (3D) model is reconstructed from the extracted skulls, brain tumors, and brain tissues. Knowing the relative site and size of a tumor within the skull is helpful to a doctor. The contours obtained by the segmentation method proposed in this study are quantitatively compared with the contours drawn by doctors on the same image set since the ground truth is unknown. The experimental results are impressive.

scholarly journals Transient Thermal Analysis of NH000 gG 100A Fuse Link Employing Finite Element Method

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1421
Author(s):  
Michał Szulborski ◽  
Sebastian Łapczyński ◽  
Łukasz Kolimas ◽  
Łukasz Kozarek ◽  
Desire Dauphin Rasolomampionona ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Ceramic Body ◽  
Three Dimensional ◽  
Operating Mode ◽  
Power Losses ◽  
Empirical Tests ◽  
Transient Thermal ◽  
Different Parts ◽  
Element Method

In this paper, a detailed three-dimensional, transient, finite element method of fuse link NH000 gG 100 A is proposed. The thermal properties during the operation of the fuses under nominal (100 A) and custom conditions (110 and 120 A) are the main focus of the analyses that were conducted. The work concerns both the outside elements of the fuse link (ceramic body) and the elements inside (current circuit). Both the distribution of the electric current and its impact on the temperature of the construction parts of the fuses during their operating mode have been described. Temperature distribution, power losses and energy dissipation were measured using a numerical model. In order to verify and validate the model, two independent teams of scientists executed experimental research, during which the temperature was measured on different parts of the device involving the rated current. Finally, the two sets of results were put together and compared with those obtained from the simulation tests. A possible significant correlation between the results of the empirical tests and the simulation work was highlighted.

Simulation of Plasto-Elastohydrodynamic Lubrication in Line Contacts of Infinite and Finite Length

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Tao He ◽  
Jiaxu Wang ◽  
Zhanjiang Wang ◽  
Dong Zhu
Keyword(s):  
Surface Roughness ◽  
Finite Length ◽  
3D Model ◽  
Three Dimensional ◽  
Elastohydrodynamic Lubrication ◽  
Axial Direction ◽  
Contact Length ◽  
Line Contact ◽  
Line Contacts ◽  
3D Surface Topography

Line contact is common in many machine components, such as various gears, roller and needle bearings, and cams and followers. Traditionally, line contact is modeled as a two-dimensional (2D) problem when the surfaces are assumed to be smooth or treated stochastically. In reality, however, surface roughness is usually three-dimensional (3D) in nature, so that a 3D model is needed when analyzing contact and lubrication deterministically. Moreover, contact length is often finite, and realistic geometry may possibly include a crowning in the axial direction and round corners or chamfers at two ends. In the present study, plasto-elastohydrodynamic lubrication (PEHL) simulations for line contacts of both infinite and finite length have been conducted, taking into account the effects of surface roughness and possible plastic deformation, with a 3D model that is needed when taking into account the realistic contact geometry and the 3D surface topography. With this newly developed PEHL model, numerical cases are analyzed in order to reveal the PEHL characteristics in different types of line contact.

Facial reconstruction project

1970 ◽  
Vol 80 (1) ◽  
Author(s):  
Federico Cesarani ◽  
Maria Cristina Martina ◽  
Valter Capussotto ◽  
Andrea Giuliano ◽  
Renato Grilletto ◽  
...  
Keyword(s):  
3D Model ◽  
Multidetector Ct ◽  
Three Dimensional ◽  
Facial Reconstruction ◽  
Digital Data ◽  
Egyptian Mummy ◽  
Ancient Egyptian ◽  
Synthetic Materials ◽  
Reconstruction Project

Facial reconstruction of mummies and corpses is important in anthropological, medical and forensic studies. The purpose of our study was to evaluate the role of three- Dimensional Multidetector CT examination for 3D facial reconstruction. We present a multidisciplinary work performed by radiologists, anthropologists and forensic police in reconstructing the possible physiognomy of an ancient Egyptian mummy. Three-Dimensional data were obtained from a well-preserved completely wrapped Egyptian mummy from the collection of the Egyptian Museum in Torino, Italy, dated from XXII or XXIII dynasty (945-715 BC). Data were used as a model for the rapid prototyping stereolithographic technique, a method which allows the creation of 3D model with digital data using synthetic materials such as resin or nylon.

3D simulations of warm and hot Jupiter atmospheres: the role of 3D mixing in shaping CH4-to-CO conversion pathways

2021 ◽  
Author(s):  
Maria Zamyatina ◽  
Eric Hebrard ◽  
Nathan Mayne ◽  
Benjamin Drummond
Keyword(s):  
Chemical Structure ◽  
Three Dimensional ◽  
Chemical Species ◽  
Radiation Chemistry ◽  
3D Simulations ◽  
Horizontal Advection ◽  
Co Conversion ◽  
Area Of Influence ◽  
Different Parts

<p>We present results from a set of cloud-free simulations of exoplanet atmospheres using a coupled three-dimensional (3D) hydrodynamics-radiation-chemistry model. We report in particular our investigation of the thermodynamic and chemical structure of the atmospheres of HAT-P-11b and WASP-17b and their comparison with the results for the atmospheres of HD 189733b and HD 209458b presented in Drummond et al. (2020). We found that the abundances of chemical species from simulations with interactive chemistry depart from their respective abundances computed at local chemical equilibrium, especially at higher latitudes. To understand this departure, we analysed the CH<sub>4</sub>-to-CO conversion pathways within the Venot et al. (2019) reduced chemical network used in our model using a chemical network analysis. We found that at steady state nine CH<sub>4</sub>-to-CO conversion pathways manifest in our 3D simulations with interactive chemistry, with different pathways dominating different parts of the atmosphere and their area of influence being determined by the vertical and horizontal advection and shifting between planets.</p>

Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Motion Direction ◽  
B Spline ◽  
And Topology ◽  
Printing System ◽  
3D Printed ◽  
Printed Patterns

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

Segregation Patterns and the Phase-Field 3D-Model for Adiabatic Phase Transition in Al-Cu Alloys

2013 ◽  
Vol 668 ◽  
pp. 870-874
Author(s):  
Heng Min Ding ◽  
Tie Qiao Zhang ◽  
Lv Chun Pu
Keyword(s):  
Dendritic Growth ◽  
3D Model ◽  
Three Dimensional ◽  
Cartesian Grid ◽  
Solute Diffusion ◽  
Solute Redistribution ◽  
Cu Alloys ◽  
Solid Phases ◽  
Solid Liquid ◽  
Liquid And Solid Phases

In the paper, a model basing on solute conservative in every unit is developed for solving the solute diffusion equation during solidification. The model includes time-dependent calculations for temperature distribution, solute redistribution in the liquid and solid phases. Three-dimensional computations are performed for Al-Cu dendritic growth into an adiabatic and highly supersaturated liquid phase. A numerical algorithm was developed to explicitly track the sharp solid/liquid (S/L) interface on a fixed Cartesian grid. Three-dimensional mesoscopic calculations were performed to simulate the evolution of equiaxed dendritic morphologies.

scholarly journals Dynamic modeling of tunnel survey spatiotemporal data

2014 ◽  
Vol 20 (2) ◽  
pp. 354-375
Author(s):  
Xiaolong Li ◽  
Jiansi Yang ◽  
Bingxuan Guo ◽  
Hua Liu ◽  
Jun Hua
Keyword(s):  
Survey Data ◽  
Cross Section ◽  
Cross Sections ◽  
3D Modeling ◽  
3D Model ◽  
Three Dimensional ◽  
Spatiotemporal Data ◽  
Excavation Process ◽  
Special Cases ◽  
Time Stamps

Currently, for tunnels, the design centerline and design cross-section with time stamps are used for dynamic three-dimensional (3D) modeling. However, this approach cannot correctly reflect some qualities of tunneling or some special cases, such as landslips. Therefore, a dynamic 3D model of a tunnel based on spatiotemporal data from survey cross-sections is proposed in this paper. This model can not only playback the excavation process but also reflect qualities of a project typically missed. In this paper, a new conceptual model for dynamic 3D modeling of tunneling survey data is introduced. Some specific solutions are proposed using key corresponding technologies for coordinate transformation of cross-sections from linear engineering coordinates to global projection coordinates, data structure of files and database, and dynamic 3D modeling. A 3D tunnel TIN model was proposed using the optimized minimum direction angle algorithm. The last section implements the construction of a survey data collection, acquisition, and dynamic simulation system, which verifies the feasibility and practicality of this modeling method.

scholarly journals Reconstrucción digital 3D del patrimonio histórico de Agustín de Betancourt: la máquina para cortar hierba en canales navegables

2016 ◽  
Vol 7 (14) ◽  
pp. 20
Author(s):  
José Ignacio Rojas-Sola ◽  
José Porras-Galán ◽  
Laura García-Ruesgas
Keyword(s):  
Cultural Heritage ◽  
History Of Science ◽  
3D Model ◽  
Civil Engineering ◽  
Three Dimensional ◽  
Baseline Information ◽  
History Of ◽  
Eighteenth And Nineteenth Centuries ◽  
Solid Edge

Agustín de Betancourt y Molina was one of the most distinguished engineers of the eighteenth and nineteenth centuries with numerous contributions to various fields of engineering, including civil engineering. This research shows the process followed in the documentation of the cultural heritage of that Canary engineer, especially in the geometric documentation of a machine for cutting grass in waterways presented in England in 1795 after three years researching on theory of machines. The baseline information has been recovered from the Canary Orotava Foundation of History of Science who has spent years collecting information about the Project Betancourt, in particular, planimetric information as well as a small report on its operation and description of parts of machine. From this information, we have constructed a three dimensional (3D) model using CAD techniques with the use of Solid Edge ST7 parametric software, which has enabled the team to create the 3D model as well as different detail plans and exploded views.

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