• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.3
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• pp.261-269
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• 2003

Steel bridges, which have been damaged by load and corrosion, need repair or strengthening. In general, before the repair welding procedure, cutting procedure carry out. Therefore, the investigating of the behavior of stress generated by cutting is so important for safety of structure. Residual stress produced by gas cutting was analyzed using 2D and 3D thermal elasto plastic FEM. According to the results, the magnitude of temperature was analyzed by 2D FEM is smaller than that was analyzed using the 3D FEM program at the start and end edge of flange. And the magnitude and distribution of residual stress of perpendicular to the cutting line was analyzed by the 2D FEM program was similar to that was analyzed by the 3D FEM program. Therefore, it is possible to predict of cutting stress by 2D and 3D FEM.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.942-948
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• 2011

This paper deals with characteristic analysis of axial flux permanent magnet (AFPM) machines with axially magnetized PM rotor using quasi-3-D analysis modeling. On the basis of magnetic vector potential and a two-dimensional (2-D) polar-coordinate system, the magnetic field solutions due to various PM rotors are obtained. In particular, 3-D problem, that is, the reduction of magnetic fields near outer and inner radius of the PM is solved by introducing a special function for radial position. And then, the analytical solutions for back-emf and torque are also derived from magnetic field solutions. The predictions are shown in good agreement with those obtained from 3-D finite element analyses (FEA). Finally, it can be judged that analytical solutions for electromagnetic quantities presented in this paper are very useful for the AFPM machines in terms of following items : initial design, sensitivity analysis with design parameters, and estimation of control parameters.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.68-73
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• 2013

In recent years, the developments in 3D technologies have initiated the commercialization of 3D services on mobile devices. For this purpose, stereoscopic 3D technology is used, which enables 3D TV on mobile devices including smartphone with glasses-free 3D viewing. As a result, the issues related with stereo imaging have been spotlighted greatly. Especially, three MPEG coding standards are provided for mobile 3D services, namely H.264/AVC with and without SEI message and H.264/MVC. In this respect, this paper presents an overview of developments in stereoscopic technologies for mobile devices to gain some perspective on the changes and progress. in this paper, we verified the availability of android based stereoscipic 3D technology related with mobile 3D TV and Smartphone with special emphasis on 3D video format and 3D features by various technollogy characteristics analysis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.4
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• pp.168-174
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• 2013

Objectives: The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. Materials and Methods: A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The patients were classified into two groups. Patients in group 1 were evaluated for symmetry in the middle 1/3 of the face and asymmetry in the lower 1/3 of the face, and those in group 2 for asymmetry of both the middle and lower 1/3 of the face. Results: In group 1, significant differences were observed in nine values out of 14 values. Values included three from anteroposterior cephalometric radiograph measurement values (cant and both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). In group 2, comparison between 2D and 3D showed significant difference in 10 factors. Values included four from anteroposterior cephalometric radiograph measurement values (both maxillary height, both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). Conclusion: Information from 2D analysis was inaccurate in several measurements. Therefore, in asymmetry patients, 3D analysis is useful in diagnosis of asymmetry.

• Journal of Cardiovascular Imaging
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• v.31 no.4
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• pp.180-187
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• 2023

BACKGROUND: Two-dimensional (2D) transesophageal echocardiography (TEE) is commonly used for assessing patients undergoing transcatheter atrial septal defect (ASD) device closure. 3D TEE, albeit providing high resolution en-face images of ASD, is used in only a fraction of cases. We aimed to perform a comparative analysis between 3D and 2D TEE assessment for ASD device planning. METHODS: This was a prospective, observational study conducted over a period of one year. Patients deemed suitable for device closure underwent 2D and 3D TEE at baseline. Defect characteristics, assessed separately in both modalities, were compared. Using regression analysis, we aimed to derive an equation for predicting device size using 3D TEE parameters. RESULTS: Thirty patients were included in the study, majority being females (83%). The mean age of the study population was 40.5 ± 12.05 years. Chest pain, dyspnea and palpitations were the common presenting complaints. All patients had suitable rims on 2D TEE. A good agreement was noted between 2D and 3D TEE for measured ASD diameters. 3D TEE showed that majority of defects were circular in shape (60%). The final device size used had high degree of correlation with 3D defect area and circumference. An equation was devised to predict device size using 3D defect area and circumference. The mean device size obtained from the equation was similar to the actual device size used in the study population (p = 0.31). CONCLUSIONS: Device sizing based on 3D TEE parameters alone is equally effective for transcatheter ASD closure as compared to 2D TEE.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.7
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• pp.39-44
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• 2012

This paper deals with the characteristic analysis of small power brushless DC (BLDC) motor considering the rotor magnet overhang flux. In the driving characteristics analysis using 2D FEA (Finite Element Analysis), the rotor magnet overhang effect can't be considered and it should be neglected. To consider rotor magnet overhang effect, 3D FEA should be required. But 3D FEA requires very long calculation time even though the high specification computer is used. In this paper, the 3D electromagnetic model of BLDC motor is approximated as the 2D electromagnetic model considering overhang effect. In this paper, the concept of overhang coefficient is applied, and the coefficient according to load torque variance is deduced.

• Biomedical Science Letters
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• v.27 no.2
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• pp.105-110
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• 2021

Short Tandem Repeats (STR) analysis which characterized by genetic polymorphism has been widely used in the forensic genetic fields. Unfortunately, mutation occurred in various STR loci could make it difficult to interpret STR data. Thus, the mutation rate of STR loci plays an important role for the data interpretation in human identification and paternity test. To verify the mutation of the STR loci in the Korean population, 545 trio sets (father, mother, and child) were analyzed with two commercial STR kits that include the 23 autosomal STR loci (D1S1656, TPOX, D2S441, D2S1338, D3S1358, FGA, D5S818, CSF1PO, D7S820, D8S1179, D10S1248, TH01, D12S391, VWA D13S317, D16S539, D18S51, D19S433, D21S11, D22S1045, SE33, Penta E and Penta D). As a result, 36 mutations were observed in 14 STR loci. The types of mutation were also classified by the increase or decrease of the alleles. The overall mutation rate was 1.4×10^-3, and the paternal mutation rate was four times higher than that of the maternal. This study will provide more detailed criterion for human identification by the mutation rate of STR loci in the Korean population.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.180-186
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• 2006

In this study, a large-scale laboratory model test, 2-D and 3-D numerical analyses were conducted to verify the reinforcement effect by utilizing geotextile bag on the railway roadbed. Static loading which simulated train load was applied on the geotextile bag-reinforced railway roadbed and also unreinforced railway roadbed, Computer program named Pentagon which is a part of FEM programs was used in the numerical analysis. Based on the results of laboratory test, 2-D and 3-D numerical analyses, the effect of load distribution and settlement reduction was found to be depending on the geotextile characteristics, tensile strength of geotextite, and interface friction angle between geotextile bags. In general, the result of 2-D and 3-D numerical analyses shows lower value than that of laboratory test. Also, the result of 3-D numerical analyses shows lower value than that of 2-D numerical analyses because of its stress transfer effect.

• Journal of International Society for Simulation Surgery
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• v.3 no.2
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• pp.69-73
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• 2016

Traditionally 2D cephalometric analysis has been used for diagnosis and treatment of maxillofacial deformities. However, 2D has some limitations in diagnosis and treatment planning especially facial asymmetry cases. The most weakness of 2D is overlapping and unpredictability. Today 3D treatment tools are used by many maxillofacial surgeons. 3D treatment tools can show ungarbled facial anatomy and do virtual surgery. The aim of this report is to present usefulness of using 3D analysis and virtual orthognathic surgery for severe facial asymmetry patients.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.68-74
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• 2001

A design and implementation method for the UHF-band(800MHz) variable attenuator using the 3dB coupler is proposed. The 90 degree, 3-dB Coupler is used for the variable attenuator. The principal theory for the 3-dB coupler is introduced. The 3-dB Coupler is designed by the mathematical analysis and a computer simulation tool. A PIN diode is used for the variable resistor at UHF-band. The variable attenuator using the 3-dB coupler and the PIN diode is designed and implemented. The measured results for the variable attenuator by a network analyzer show that the insertion loss is below -l0dB, and the continuous variable attenuation range is about 10dB.