• Journal of Dental Rehabilitation and Applied Science
• /
• v.31 no.2
• /
• pp.112-125
• /
• 2015

Making a model that is an accurate replica of the oral structure requires precision and efficiency. Nowadays, rapid technological advances bring digitalization in dentistry. One of the most important works in digital dentistry is three-dimensional modeling of the oral cavity and digitizing the 3D data. Among the three components of CAD/CAM, (1) data capture component (digitizers), (2) design component (CAD software), (3) manufacturing component (CAM), the basic component that has a significant impact on the other processes is the data capture component, i.e. intra-oral scanners. This literature review discusses the principles and clinical use of intra-oral scanners in dentistry based on recent publications of the past 5 years using the PubMed and Google Scholar databases.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.9
• /
• pp.2183-2188
• /
• 2009

This paper describes an automatic mesh generation system for finite element analysis of three-dimensional cracks. It is consisting of fuzzy knowledge processing, bubble meshing and solid geometry modeler. This novel mesh generation process consists of three sub-processes: (a) definition of geometric model, i.e. analysis model, (b) generation of bubbles, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional crack structures. Bubble is generated if its distance from existing bubble points is similar to the bubble spacing function at the point. The bubble spacing function is well controlled by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Practical performances of the present system are demonstrated through several mesh generations for 3D cracks.

• Proceedings of the KOSOMBE Conference
• /
• v.1998 no.11
• /
• pp.57-59
• /
• 1998

For medical students and doctors, knowledge of the three-dimensional (3D) structure of brain is very important in diagnosis and treatment of brain diseases. Two-dimensional (2D) tools (ex: anatomy book) or traditional 3D tools (ex: plastic model) are not sufficient to understand the complex structures of the brain. However, it is not always guaranteed to dissect the brain of cadaver when it is necessary. To overcome this problem, the virtual dissection programs of the brain have been developed. However, most programs include only 2D images that do not permit free dissection and free rotation. Many programs are made of radiographs that are not as realistic as sectioned cadaver because radiographs do not reveal true color and have limited resolution. It is also necessary to make the virtual dissection programs of each race and ethnic group. We attempted to make a virtual dissection program using a 3D image of the brain from a Korean cadaver. The purpose of this study is to present an educational tool for those interested in the anatomy of the brain. The procedures to make this program were as follows. A brain extracted from a 58-years old male Korean cadaver was embedded with gelatin solution, and serially sectioned into 1.4 mm-thickness using a meat slicer. 130 sectioned specimens were inputted to the computer using a scanner ($420\times456$ resolution, true color), and the 2D images were aligned on the alignment program composed using IDL language. Outlines of the brain components (cerebrum, cerebellum, brain stem, lentiform nucleus, caudate nucleus, thalamus, optic nerve, fornix, cerebral artery, and ventricle) were manually drawn from the 2D images on the CorelDRAW program. Multimedia data, including text and voice comments, were inputted to help the user to learn about the brain components. 3D images of the brain were reconstructed through the volume-based rendering of the 2D images. Using the 3D image of the brain as the main feature, virtual dissection program was composed using IDL language. Various dissection functions, such as dissecting 3D image of the brain at free angle to show its plane, presenting multimedia data of brain components, and rotating 3D image of the whole brain or selected brain components at free angle were established. This virtual dissection program is expected to become more advanced, and to be used widely through Internet or CD-title as an educational tool for medical students and doctors.

• The Research Journal of the Costume Culture
• /
• v.10 no.6
• /
• pp.709-717
• /
• 2002

In the apparel industry, the technology has been advanced rapidly. The use of 3D scanning systems fur the capture and measurement of human body is becoming common place. Three dimensional digital image can be used for design, inspection, reproduction of physical objects. The purpose of this study is to develop a method that drafts men's basic bodice pattern from scanned 3D body surface shape data. In order to pursue this purpose the researchers developed pattern drafting algorithm. The 3D scanner used in this study was Cyberware Whole Body Scanner WB-4. The bodice pattern drafting algorithm from 3D body surface shape data developed in this study is as follows. First, convert geometric 3D body surface data to 3D polygonal mesh data. Second, develop algorithm to lay out 3D polygonal patches onto a plane using Auto Lisp program. The polygon meshes are coplanar, and the individual mesh is continuously in contact with next one The bodice front surface shape data in polygonal patches form was lined up in bust and waist levels. The back bodice was drafted by lining up the polygonal mesh in scapula, chest, and waist levels. in the drafts, gaps between polygons were formed into the darts.

• Journal of information and communication convergence engineering
• /
• v.17 no.2
• /
• pp.91-96
• /
• 2019

In this study, a system to increase the expressiveness of existing standard terminology using three-dimensional (3D) data is designed. We analyze the existing medical terminology system by searching the reference literature and perform an expert group focus survey. A human body image is generated using a 3D modeling tool. Then, the anatomical position of the human body is mapped to the 3D coordinates' identification (ID) and metadata. We define the term to represent the 3D human body position in a total of 12 categories, including semantic terminology entity and semantic disorder. The Blender and 3ds Max programs are used to create the 3D model from medical imaging data. The generated 3D human body model is expressed by the ID of the coordinate type (x, y, and z axes) based on the anatomical position and mapped to the semantic entity including the meaning. We propose a system of standard terminology enabling integration and utilization of the 3D human body model, coordinates (ID), and metadata. In the future, through cooperation with the Electronic Health Record system, we will contribute to clinical research to generate higher-quality big data.

• Investigative Magnetic Resonance Imaging
• /
• v.21 no.3
• /
• pp.131-138
• /
• 2017

Purpose: To optimize the timing of scans using cardiac magnetic resonance contrast-enhanced timing robust angiography (CMR-CENTRA) for electroanatomic mapping (EAM) of the right atrium (RA) and left atrium (LA) in patients with atrial fibrillation (AF). Materials and Methods: Fifty patients with AF (38 men; mean age, $59.6{\pm}9.3years$) underwent CMR-CENTRA in preparation for EAM. The CMR-CENTRA data were acquired at five different scan times: 0 seconds, 5 seconds, 10 seconds, 15 seconds, and 20 seconds after an intravenous injection of contrast media. To evaluate the degree of contrast enhancement, right atrial relative contrast (RA-RC) and left atrial relative contrast (LA-RC) on the CMR-CENTRA scans were assessed at each time point. The three-dimensional (3D) reconstruction of the RA and LA for the EAM system was performed using the CMR-CENTRA data. Results: A CMR-CENTRA at a scan time of 10 seconds showed significantly greater LA-RC (P < 0.05) compared with all other scan times. A CMR-CENTRA at a scan time of 15 seconds showed significantly greater RA-RC (P < 0.05) compared with all other scan times. In the 3D reconstruction of the RA, the success rates of CMR-CENTRA at scan times of 10 seconds and 15 seconds were 18% and 100%, respectively. In the 3D reconstruction of the LA, the success rates of CMR-CENTRA at 10- and 15-second scan times were 100%. Conclusion: The CMR-CENTRA data acquired at 15 seconds after the injection of contrast media is appropriate for the preparation of an EAM system that is focused on the RA and LA in patients with AF.

• International Journal of Highway Engineering
• /
• v.10 no.4
• /
• pp.213-224
• /
• 2008

Flexible pavement responses to vehicular loading, such as critical stresses and strains, in each pavement layer, could be predicted by the multilayered elastic analysis. However, multilayered elastic theory suffers from major drawbacks including spatial dimension of a numerical model, material properties considered in the analysis, boundary conditions, and ill-presentation of tire-pavement contact shape and stresses. To overcome these shortcomings, three-dimensional finite element (3D FE) models are developed and numerical analyses are conducted to calculate pavement responses to moving load in this study. This paper introduces a methodology for an effective 3D FE to simulate flexible pavement structure. It also discusses the mesh development and boundary condition analysis. Sensitivity analyses of flexible pavement response to loading are conducted. The infinite boundary conditions and time-dependent history of calculated pavement responses are considered in the analysis. This study found that the outcome of 3D FE implicit dynamic analysis of flexible pavement that utilizes appropriate boundary conditions, continuous moving load, viscoelastic hot-mix asphalt model is comparable to field measurements.

• Nuclear Engineering and Technology
• /
• v.36 no.6
• /
• pp.528-539
• /
• 2004

It is essential in commercial reactors that the safety limits imposed on the fuel pellets and fuel clad barriers, such as the linear power density (LPD) and the departure from nucleate boiling ratio (DNBR), are not violated during reactor operations. In order to accurately monitor the safety limits of current reactor states, a detailed three-dimensional (3D) core power distribution should be estimated from the in-core detector signals. In this paper, we propose a calculation methodology for detailed 3D core power distribution, using in-core detector signals and core monitoring constants such as the 3D Coupling Coefficients (3DCC), node power fraction, and pin-to-node factors. Also, the calculation method for several core safety parameters is introduced. The core monitoring constants for the real core state are promptly provided by the core design code and on-line MASTER (Multi-purpose Analyzer for Static and Transient Effects of Reactors), coupled with the core monitoring program. through the plant computer, core state variables, which include reactor thermal power, control rod bank position, boron concentration, inlet moderator temperature, and flow rate, are supplied as input data for MASTER. MASTER performs the core calculation based on the neutron balance equation and generates several core monitoring constants corresponding to the real core state in addition to the expected core power distribution. The accuracy of the developed method is verified through a comparison with the current CECOR method. Because in all the verification calculation cases the proposed method shows a more conservative value than the best estimated value and a less conservative one than the current CECOR and COLSS methods, it is also confirmed that this method secures a greater operating margin through the simulation of the YGN-3 Cycle-1 core from the viewpoint of the power peaking factor for the LPD and the pseudo hot pin axial power distribution for the DNBR calculation.

• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.11
• /
• pp.529-536
• /
• 2015

When rendering both three-dimensional objects and photo images together, the non-photorealistic rendering results are in visual discord since the two contents have their own independent color distributions. This paper proposes a non-photorealistic rendering technique which renders both three-dimensional objects and photo images such as cartoons and sketches. The proposed technique computes the color distribution property of the photo images and reduces the number of colors of both photo images and 3D objects. NPR is performed based on the reduced colormaps and edge features. To enhance the natural scene presentation, the image region segmentation process is preferred when extracting and applying colormaps. However, the image segmentation technique needs a lot of computational operations. It takes a long time for non-photorealistic rendering for large size frames. To speed up the time-consuming segmentation procedure, we use GPGPU for the parallel computing using the GPU. As a result, we significantly improve the execution speed of the algorithm.

• Physical Therapy Korea
• /
• v.26 no.3
• /
• pp.99-105
• /
• 2019

Background: Although magnetic resonance imaging is accurate, it is expensive to measure the movement of temporomandibular joint. The three-dimensional (3D) motion analysis system is an inexpensive measurement tool. Objects: This study examined the reliability of quantifying the mouth opening and lateral mandibular shift and differences between individuals with and without temporomandibular disorder (TMD) using the hygienic method of surface markers on the skin with 3D ultrasound-based motion analysis. Methods: This study included 24 subjects (12 with and 12 without TMD). Temporomandibular joint motion during mouth opening was recorded using two surface markers with 3D ultrasound-based motion analysis. An intraclass correlation coefficient [ICC (3,k)] was used to confirm the intrarater reliability of quantifying kinematic temporomandibular joint motion, and an independent t-test was used to evaluate differences in maximal mouth opening and lateral mandibular shift between the two groups. Results: Assessment of mouth opening and lateral mandibular shift showed excellent test-retest reliability with low standard error of measurement. The lateral mandibular shift and opening-lateral mandibular shift ratio were significantly increased in the TMD group during maximum mouth opening (p<.05). However, no significant difference in maximal mouth opening was observed between the groups with and without TMD (p>.05). Conclusion: This hygienic and simple surface marker method can be used to quantify the mouth opening and lateral mandibular shift at the end-range of mouth opening. The TMD group showed an increased lateral mandibular shift movement at the end-range of mouth opening. The lateral mandibular shift movement can be regarded as a symptom in the diagnosis and treatment of TMD.