• Biomaterials and Biomechanics in Bioengineering
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• v.5 no.1
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• pp.25-35
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• 2020

We carry the knowledge that the skeleton bones of the human body are not always without defects and some various defects could occur in them. In the present paper, as the first endeavor, free vibration and buckling analysis of femur bones with femoral defects are investigated. A major strength of this study is the modeling of defects in femur bones. Materialise Mimics software is adopted to model the bone geometry and the SOLIDWORKS software is used to generate the defects in bones. Next, the ABAQUS software is employed to study the behaviors of bones with defects.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.4
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• pp.47-52
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• 2010

This paper describes a visualization technique that animates geometrical defect data that are extracted using a magnetic flux leakage (MFL) operating system on nondestructive evaluation (NDE). Since data are collected from different locations and often not regular, the data must be converted to the standard format that is used within the pipeline in visualization procedures. In order to navigate inside of the pipeline, 3D virtual objects are generated and are able to explore the pipeline continuously. The major objectives of this paper are to characterize, generate general shape of defects, and enable computer interaction in virtual environment. Pipeline navigation system (PNS) has introduced the framework for interactive visual applications based upon the principles of modeling 3D objects. PNS presents some preliminary efforts to enable the user to interact human and computer with each other.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.557-564
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• 2023

In this study, 3D printing technology was used to compensate for the shortcomings of the use of lead, which has proven to have excellent shielding performance, and to control unnecessary human exposure. 3D printers can implement three-dimensional shapes and can immediately apply individual ideas, which has great advantages in maintaining technology supplementation while reducing the cost and duration of prototyping. Among the various special 3D printers, the FDM method was adopted, and the filament used for output was manufactured using a research extruder by mixing two materials, PLA (Poly-Lactic-Acid) and tungsten. The purpose was to verify the validity through dose evaluation and to provide basic information on the production of chapezones of various materials. The mixed filament was implemented as a morphological shield. Filaments made of a research extruder by mixing PLA and tungsten were divided into 10 %, 20 %, 30 %, 40 %, and 50 % according to the tungsten content ratio. Through the process of 3D Modeling, STL File storage, G-code generation, and output, 10 cm × 10 cm × 0.5 cm was manufactured, respectively, and dose and shielding ability were evaluated under the conditions of tube voltages of 60 kVp, 80 kVp, 100 kVp, 120 kVp, and tube currents of 20 mAs and 40 mAs.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.433-441
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• 2017

The 3D printing selective laser sintering (SLS) and stereo lithography apparatus (SLA) method used for bone model production has good precision and resolution, but the printers are expensive and need professional knowledge for operation. The program that converts computed tomography digital imaging and communications in medicine (DICOM) file into STL (stereolithography) file is also expensive so requesting 3D printing companies takes a lot of time and cost, which is why they are not generally utilized in surgery. To produce bone models of fractured patients, the use of 3D imaging conversion program and 3D printing system should be convenient, and the cost of device and operation should be low. Besides, they should be able to produce big size bone models for application to surgery. Therefore, by using an fused deposition modeling (FDM) method 3D printer that uses thermoplastic materials such as DICOM Viewer OsiriX and plastic wires, this study developed 3D printing system for Fracture surgery Patients customized bone model production for many clinics to use for surgery of fracture patients by universalizing with no limit in printing sizes and low maintenance and production cost. It is expected to be widely applied to the overall areas of orthopedics' education, research and clinic. It is also expected to be conveniently used in not only university hospitals but also regular general hospitals.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.41-47
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• 2021

Purpose: This study aimed to compare the accuracy of 3-dimensional(3D) printed models derived from multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) systems with different fields of view (FOVs). Materials and Methods: Five human dry mandibles were used to assess the accuracy of reconstructions of anatomical landmarks, bone defects, and intra-socket dimensions by 3D printers. The measurements were made on dry mandibles using a digital caliper (gold standard). The mandibles then underwent MDCT imaging. In addition, CBCT images were obtained using Cranex 3D and NewTom 3G scanners with 2 different FOVs. The images were transferred to two 3D printers, and the digital light processing (DLP) and fused deposition modeling (FDM) techniques were used to fabricate the 3D models, respectively. The same measurements were also made on the fabricated prototypes. The values measured on the 3D models were compared with the actual values, and the differences were analyzed using the paired t-test. Results: The landmarks measured on prototypes fabricated using the FDM and DLP techniques based on all 4 imaging systems showed differences from the gold standard. No significant differences were noted between the FDM and DLP techniques. Conclusion: The 3D printers were reliable systems for maxillofacial reconstruction. In this study, scanners with smaller voxels had the highest precision, and the DLP printer showed higher accuracy in reconstructing the maxillofacial landmarks. It seemed that 3D reconstructions of the anterior region were overestimated, while the reconstructions of intra-socket dimensions and implant holes were slightly underestimated.

• Journal of Korea Multimedia Society
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• v.15 no.4
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• pp.417-424
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• 2012

In this paper, we propose an automatic system that recognizes dynamic human gestures activity, including Arabic numbers from 0 to 9. We assume the gesture trajectory is almost in a plane that called principal gesture plane, then the Least Squares Method is used to estimate the plane and project the 3-D trajectory model onto the principal. An improved FNN model combined with HMM is proposed for dynamic gesture recognition, which combines ability of HMM model for temporal data modeling with that of fuzzy neural network. The proposed algorithm shows that satisfactory performance and high recognition rate.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.7-16
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• 2010

The great growth and development in the automobile industry have been made at the hardware site consisting of Car over about 100 years. The biggest key of future automobile industry with fierce competition is up to product development with high customer satisfaction through the ergonomics that is applied to car efficiently and effectively. Until Now, The Study of Ergonomics has been used for effective Car design. But At the 21st Century automotive, it will be used for Survival through the differentiation and merchantability of vehicle in highly competitive. That is a big difference. We will review the role of ergonomics in the vehicle development stage with Ssangyong Case.

• Journal of Integrative Natural Science
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• v.6 no.4
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• pp.205-210
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• 2013

Human P-gp is a protein responsible for the multidrug resistance (MDR) and causes failure of cancer chemotherapy. Till date no X-ray crystal structure is reported for this membrane protein, which hampers active research in the field. We performed homology modeling to develop three dimensional (3D) model of P-gp, and docking studies of the verapamil and curcumin have been performed to gain insight into the interaction mechanism between inhibitors and P-gp. It was identified that the inhibitors docked into the upper part of P-gp and interacted through the hydrophobic interactions.

• Journal of KIISE:Software and Applications
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• v.35 no.12
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• pp.780-788
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• 2008

Modeling hand poses and tracking its movement are one of the challenging problems in computer vision. There are two typical approaches for the reconstruction of hand poses in 3D, depending on the number of cameras from which images are captured. One is to capture images from multiple cameras or a stereo camera. The other is to capture images from a single camera. The former approach is relatively limited, because of the environmental constraints for setting up multiple cameras. In this paper we propose a method of reconstructing 3D hand poses from a 2D input image sequence captured from a single camera by means of Belief Propagation in a graphical model and recognizing a finger clicking motion using a hidden Markov model. We define a graphical model with hidden nodes representing joints of a hand, and observable nodes with the features extracted from a 2D input image sequence. To track hand poses in 3D, we use a Belief Propagation algorithm, which provides a robust and unified framework for inference in a graphical model. From the estimated 3D hand pose we extract the information for each finger's motion, which is then fed into a hidden Markov model. To recognize natural finger actions, we consider the movements of all the fingers to recognize a single finger's action. We applied the proposed method to a virtual keypad system and the result showed a high recognition rate of 94.66% with 300 test data.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.6
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• pp.545-551
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• 2017

It is very important to effectively obtain the information related to the human body shape for user-centered design. The human body shape is a huge combination of various irregular curves and is typically obtained by a 3-D Scanner. 3-D scanners show high reliability; however, they are expnsive equipment with limited mobility. 3-D models of irregular-shaped curves were created by a photogrammetric approach and the errors between the original curve and the models were evaluated. 3-D models were created based on 160, 80, 40, 20, 10, and 5 marking points evenly located on the original curve. In the case of convex curve, low levels of residuals were observed in the models from 160, 80, 40, and 20 marking points (0.13% max). In the combination of convex and concave curves, relatively low levels of residuals were observed in the models from 160, 80, and 40 marking points (0.29%). It is possible to conclude that marking points should be placed at every 5% of overall length of a convex curve and at every 2.5% of overall length of a curve with convex and concave curve in order to maintain low levels of errors. A photogrammetric approach can be used as an alternative for the 3-D scanners with advantages of low cost and mobility.