scholarly journals Segmentación de mallas 3d de edificios históricos para levantamiento arquitectónico

2018 ◽  
Vol 9 (18) ◽  
pp. 66
Author(s):  
Borja Javier Herráez ◽  
Eduardo Vendrell
Keyword(s):  
Feature Detection ◽  
3D Model ◽  
Three Dimensional ◽  
Recognition Algorithm ◽  
Mesh Segmentation ◽  
Historic Buildings ◽  
3D Mesh ◽  
Fields Of Study ◽  
Computer Based ◽  
3D Acquisition

<p>Advances in three-dimensional (3D) acquisition systems have introduced this technology to more fields of study, such as archaeology or architecture. In the architectural field, scanning a building is one of the first possible steps from which a 3D model can be obtained and can be later used for visualisation and/or feature analysis, thanks to computer-based pattern recognition tools. The automation of these tools allows for temporal savings and has become a strong aid for professionals, so that more and more methods are developed with this objective. In this article, a method for 3D mesh segmentation focused  on  the representation  of  historic  buildings  is  proposed.  This  type  of  buildings is characterised  by  having singularities  and features in  façades, such  as  doors  or  windows. The  main  objective  is  to  recognise  these  features, understanding them as those parts of the model that differ from the main structure of the building. The idea is to use a recognition algorithm for planar faces that allows users to create a graph showing the connectivity between them, therefore allowing the reflection of the shape of the 3Dmodel. At a later step, this graph is matched against some pre-defined graphs that  represent  the  patterns  to  look  for. Each  coincidence  between  both  graphs  indicate  the  position  of  one  of  the characteristics sought. The developed method has proved to be effective for feature detection and suitable for inclusion in architectural surveying applications.</p>

Fabrication of Maxillofacial Implant Using CAD CAM System

2010 ◽  
Vol 146-147 ◽  
pp. 353-356
Author(s):  
Se Kou Singare ◽  
Li Wang ◽  
Shou Yan Zhong ◽  
Guang Hui Xu ◽  
Wei Ping Wang ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
3D Model ◽  
Maxillofacial Surgery ◽  
Bone Defects ◽  
Bony Defect ◽  
Cad Cam ◽  
Computer Based ◽  
3D Acquisition ◽  
Aided Design ◽  
Individual Implant

We present an approach that combines Computer Tomography (CT), reverse engineering (RE) and rapid prototyping (RP) for individual implant production in maxillofacial surgery. 3D acquisition of the patient’s skull is performed, after acquisition of data; an individual computer-based 3D model of the bony defect is generated. These data are transferred into RE software to create the implant using a computer-aided design (CAD) model, which is directed into the RP machine for the production of the physical model. The implant is then directly used in investment casting such as “Quick Cast” pattern to produce the titanium model. In the clinical reports presented here, reconstructions of one patient with mandible bone defects were performed using this method. The custom prostheses perfectly fit the defects during the operations, and surgery time was reduced.

3D MRI Models of the Musculoskeletal System

2021 ◽  
Vol 25 (03) ◽  
pp. 388-396
Author(s):  
Mohammad Samim
Keyword(s):  
Clinical Practice ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Shoulder Injuries ◽  
3D Mri ◽  
Acquisition Strategies ◽  
Structure Morphology ◽  
Computer Based ◽  
Magnetic Resonance Imaging Mri

AbstractComputed tomography (CT) is most commonly used to produce three-dimensional (3D) models for evaluating bone and joint morphology in clinical practice. However, 3D models created from magnetic resonance imaging (MRI) data can be equally effective for comprehensive and accurate assessment of osseous and soft tissue structure morphology and pathology. The quality of 3D MRI models has steadily increased over time, with growing potential to replace 3D CT models in various musculoskeletal (MSK) applications. In practice, a single MRI examination for two-dimensional and 3D assessments can increase the value of MRI and simplify the pre- and postoperative imaging work-up. Multiple studies have shown excellent performance of 3D MRI models in shoulder injuries, in the hip in the setting of femoroacetabular impingement, and in the knee for the creation of bone surface models. Therefore, the utility of 3D MRI postprocessed models is expected to continue to rise and broaden in applications. Computer-based and artificial intelligence–assisted postprocessing techniques have tremendous potential to improve the efficiency of 3D model creation, opening many research avenues to validate the applicability of 3D MRI and establish 3D-specific quantitative assessment criteria. We provide a practice-focused overview of 3D MRI acquisition strategies, postprocessing techniques for 3D model creation, MSK applications of 3D MRI models, and an illustration of cases from our daily clinical practice.

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.

scholarly journals A computer-based approach for developing linamarase inhibitory agents

2020 ◽  
Vol 5 (7) ◽  
Author(s):  
Lucas Paul ◽  
Celestin N. Mudogo ◽  
Kelvin M. Mtei ◽  
Revocatus L. Machunda ◽  
Fidele Ntie-Kang
Keyword(s):  
Structure Elucidation ◽  
Three Dimensional ◽  
Data Bank ◽  
Competitive Inhibitor ◽  
Industrial Applications ◽  
Dimensional Structure ◽  
Full Understanding ◽  
The Poor ◽  
Computer Based ◽  
Inhibitory Agents

AbstractCassava is a strategic crop, especially for developing countries. However, the presence of cyanogenic compounds in cassava products limits the proper nutrients utilization. Due to the poor availability of structure discovery and elucidation in the Protein Data Bank is limiting the full understanding of the enzyme, how to inhibit it and applications in different fields. There is a need to solve the three-dimensional structure (3-D) of linamarase from cassava. The structural elucidation will allow the development of a competitive inhibitor and various industrial applications of the enzyme. The goal of this review is to summarize and present the available 3-D modeling structure of linamarase enzyme using different computational strategies. This approach could help in determining the structure of linamarase and later guide the structure elucidation in silico and experimentally.

A benchmark for 3D mesh segmentation

2009 ◽  
Author(s):  
Xiaobai Chen ◽  
Aleksey Golovinskiy ◽  
Thomas Funkhouser
Keyword(s):  
Mesh Segmentation ◽  
3D Mesh

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.

Geometric simulation for warp-knitted tubular bandages with the mesh model

2021 ◽  
pp. 004051752110138
Author(s):  
Haisang Liu ◽  
Gaoming Jiang ◽  
Zhijia Dong
Keyword(s):  
Programming Languages ◽  
Three Dimensional ◽  
3D Mesh ◽  
Mesh Model ◽  
Matrix Operations ◽  
Computer Aided ◽  
Spatial Geometry ◽  
3D Mesh Model ◽  
Coordinate Mapping ◽  
Geometric Simulation

The purpose of this paper is to geometrically simulate warp-knitted medical tubular bandages with a computer-aided simulator. A flat mesh model is established according to unfolded fabric considering the knitting characteristics of double-needle bed warp-knitted tubular fabrics. Moreover, a 3D (three-dimensional) mesh model corresponding to the actual product shape is created. To better describe the spatial geometry of stitches, eight-point models are introduced, and stitches are generated with the flat mesh model. Founded on matrix operations, the stitch position in the 3D mesh model is determined through coordinate mapping. Various stitch paths are rendered in computer programming languages C# and JavaScript to conduct simulations. Warp-knitted medical tubular bandages with a large number of shapes are effectively modeled.

Development and Application of Graphics Displays for a Mini-Computer Based Vibration Analysis System

1992 ◽  
Author(s):  
Bill Trevillion
Keyword(s):  
Three Dimensional ◽  
Large Data ◽  
Electric Utility ◽  
Chemical Processing ◽  
Acoustic Data ◽  
Interactive Display ◽  
Computer Based ◽  
Data Files ◽  
Vibration Problems ◽  
Analysis System

Abstract Radian Corporation has developed extensive data display capabilities to analyze vibration and acoustic data from structures and rotating equipment. The Machinery Interactive Display and Analysis System (MIDAS) displays data collected through the acquisition functions of MIDAS. The graphics capabilities include displaying spectra in three-dimensional waterfall and in X-Y formats. Both types of plots can relate vibrations to time, equipment speed, or process parameters. Using menu-driven parameter selection, data can be displayed in formats that are the most useful for analysis. The system runs on a popular mini-computer, and it can be used with a great variety of graphics terminals, workstations, and printer/plotters. The software was designed and written for interactive display and plotting. Automatic plotting of large data files is facilitated by a batch plotting mode. The user can define display formats for the analysis of noise and vibration problems in the electric utility, chemical processing, paper, and automotive industries. This paper describes the history and development of graphics capabilities of the MIDAS system. The system, as illustrated in the examples, has proven efficient and economical for displaying large quantities of data.

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.

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