• Proceedings of the Korean Society of Life Science Conference
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• 2002.03a
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• pp.98-98
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• 2002

• Journal of Oral Medicine and Pain
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• v.44 no.1
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• pp.35-39
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• 2019

Calcifying aponeurotic fibroma (CAF) is an uncommon benign soft-tissue fibroblastic tumor with characteristic histological features. It mainly occurs in the distal part of the extremities, such as the hands and feet, in children and adolescents. Males are twice as commonly affected as females. CAF exhibits local invasiveness, and hence, its recurrence rate is also high. Therefore, complete surgical excision is both diagnostic and therapeutic. The occurrence of CAF in the maxillofacial region, especially the temporomandibular joint (TMJ), is very rare, and this necessitates its differentiation from other TMJ neoplasms. The differential diagnosis of CAF requires microscopic examination. Herein, we report a rare case of CAF located at the left mandibular condyle, which was confirmed by histopathological analysis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.1
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• pp.46-54
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• 2007

PURPOSE Osteosarcoma occurring in the head and neck region is known as a malignant tumor that shows a relatively poor prognosis and, despite various treatments, clinicians have often been confounded by it. The existence or non-existence of the mutation of the gene $p16^{INK4a}$ has been used in prognosis assessment. In this study, author have attempted to determine whether methylation of the gene $p16^{INK4a}$ could be applied to forecast the progress of osteosarcomas in the head and neck region having been given poor prognoses in the diagnostic process and the early stage of treatment. RESEARCH SUBJECT AND METHOD Clinicopathologic investigations, immunohistochemical examinations, a methylation specific polymerase reaction (MSP) analysis, and a survival analysis were conducted on the tissues of 20 patients with mandibulofacial osteosarcoma. RESULTS Neither age, sex, size, smoking or non-smoking, nor region have showed a statistical significance with methylation or unmethylation of the gene $p16^{INK4a}$ and expression rates demonstrated by immunohisto- chemical examinations. A chi-square test indicated that recurrence inclination has no relation with the expression rate of p16 protein (p=0.6615), but it showed a statistical significance with methylation of the gene $p16^{INK4a}$ (p=0.0033). With respect to investigations of the survival rates, a Kaplan-Meier survival analysis found that the manifestation rate of p16 protein did not have an impact on survival (p=0.8864), but that the methylation of the gene $p16^{INK4a}$ resulted in significant differences in survival rates (p=0.0105). CONCLUSIONS The above results show that methylation of the gene $p16^{INK4a}$ could be one of the major factors that help determine the recurrence inclination and prognosis of osteosarcomas occurring in the head and neck region.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.2
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• pp.157-164
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• 2015

The present work performs three-dimensional flow calculations based on Reynolds Averaged Navier-Stokes (RANS) and Delayed Detached Eddy Simulation (DDES) to investigate the flow field of a transonic rotor (NASA Rotor 37) at near-stall condition. It is found that the DES approach is likely to predict well the complex flow characteristics such as secondary vortex or turbulent flow phenomenon than RANS approach, which is useful to describe the flow mechanism of a transonic compressor. Especially, the DES results show improvement of predicting the flow field in the wake region and the model captures reasonably well separated regions compared to the RANS model. Besides, it is discovered that the three-dimensional vortical flows after the vortex breakdown from the rotor tip region are widely distributed and its vortex structures are clearly present. Near the rotor leading edge, a part of the tip leakage flows in DES solution spill over into next passage of the blade owing to the separation vortex flow and the backflow is clearly seen around the trailing edge of rotor tip. Furthermore, the DES solution shows strong turbulent eddies especially in the rotor hub, rotor tip section and the downstream of rotor trailing edge compared to the RANS solution.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.3 s.147
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• pp.322-330
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• 2006

Numerical calculations are carried out for flow past a circular cylinder forced oscillating normal to the free-stream flow at a fixed Reynolds number equal to 185. The cylinder oscillation frequency ranged from 0.8 to 1.2 of the natural vortex-shedding frequency, and the oscillation amplitude extended up to 20% of the cylinder diameter. IBM (Immersed Boundary Method) with direct momentum forcing was adopted to handle both of a stationary and an oscillating cylinder Present results such as time histories of drag and lift coefficients for both stationary and oscillating cases are in good agreement with previous numerical and experimental results. The instantaneous wake patterns of oscillating cylinder with different oscillating frequency ratios showed the synchronized wakes pattern in the lock-in region and vortex switching phenomenon at higher frequency ratio than the critical frequency ratio.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.6
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• pp.649-661
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• 2008

The impact of the detailed surface data on regional meteorological fields in complex coastal area is studied using RAMS. Resolutions of topography and land use data are very important to numerical modeling, because high resolution data can reflect correct terrain height and detail characteristics of the surface. Especially, in complex coastal region such as Gwangyang area, southern area in Korean Peninsula, high resolution topography and land use data are indispensable for accurate modeling results. This study investigated the effect of resolutions of terrain data using SRTM with 3 second resolution topography and KLU with 1 second resolution land use data. Case HR was the experiment using high resolution data, whereas Case LR used low resolution data. In Case HR, computed surface temperature was higher than Case LR along the coastline and wind speed was $1{\sim}2m/s$ weaker than Case LR. Time series of temperature and wind speed indicated great agreement with the observation data. Moreover, Case HR indicated outstanding results on statistical analysis such as regression, root mean square error, index of agreement.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.196-199
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• 2010

The human eyes are important facial landmarks for image normalization due to their relatively constant interocular distance. This paper introduces a novel approach for the eye detection task using optimal segmentation method for eye representation. The method consists of three steps: (1)edge extraction method that can be used to accurately extract eye region from the gray-scale face image, (2)extraction of eye region using labeling method, (3)eye localization based on intensity information. Experimental results show that a correct eye detection rate of 98.9% can be achieved on 2408 FERET images with variations in lighting condition and facial expressions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.167-170
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• 2010

In this paper, we proposed a novel algorithm to detect the center of pupil in frontal view face. This algorithm, at first, extract an eye region from the face image using integral projection function and variance projection function. In an eye region, detect the center of pupil positions using circular hough transform with sobel edge mask. The experimental results show good performance in detecting pupil center from FERET face image.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.55 no.3
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• pp.173-176
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• 2012

Oncocytic neoplasm of the head and neck region accounts for approximately 1% of all salivary gland tumors, but only 5% of oncocytic neoplasm is malignant. Oncocytic carcinoma arising in the submandibular gland is exceedingly rare. We encountered a sixty seven-year-old male patient who presented with multiple mass in the right neck. Fine needle aspiration biopsy revealed a salivary gland tumor of predominantly oncocytic form, and a differential diagnosis included oncocytic adenoma or mucoepidermoid carcinoma. A right submandibular gland resection and modified radical neck dissection were performed. Histologically, the tumor cells showed nuclear pleomorphism, and stromal invasion, which were compatible with oncocytic carcinoma. After surgery, the entire neck region was irradiated. Seventeen months after the initial surgery, multiple metastases to the bone and lung were detected from the incidental pathologic bone fracture of the right humerus; palliative chemotherapy was performed to resolve this. We report a case of oncocytic carcinoma in the submandibular gland with a review of literature.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.10
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• pp.1033-1041
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• 2012

Performance evaluation of a direct carbon fuel cell (DCFC) was conducted according to coals and a graphite particle. Several fuel properties such as thermal reactivity, textural structure, gas adsorption characteristic, and functional groups on the surface of fuels were investigated and their effects on electrochemistry were discussed. The strong carbon structure inside of fuels led the rapid potential decreasing in high current density region, because it caused small surface area and low pore volume. The functional groups on the surface were related to the low current density region. The maximum current density and power density of fuels were affected by the total carbon content in fuels. The effect of operating conditions such as stirring rate and operating temperature was investigated in this study.