• Archives of Plastic Surgery
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• v.37 no.4
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• pp.473-476
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• 2010

Purpose: Torus palatinus is a bony prominence at the middle of the hard palate. The size varies from barely discernible to very large, from flat to lobular. This oral exostosis is not a disease or a sign of disease, but if large, may be a problem. So, we present the clinical and histopathologic features and applied therapy and provide a comprehensive review of the rare case of the symptomatic exostoses. Methods: A 37-year-old woman had slowly growing exophytic nodular mass of the bone that arises the midline suture of the hard palate. The patient was concerned about discomfort associated with movement of her tongue and about frequent irritation of the palatal mucosa during mastification of the hard food. The patient had a large, unilobulated torus palatinus. It extended from the area adjacent to the canine to a point beyond the junction with the soft palate. The mass was oblong in shape, measuring about 3 cm long, 2 cm wide, and 0.8 cm in height. Results: Before surgical intervention a CT was obtained for the sake of estimating the thickness of the bone between the exostoses and the maxillary antrum and floor of the nose. The surgical procedure was performed with the patient under general anesthesia. Removal of the exostosis was performed after midline mucoperiosteal incision with osteotome and diamond burr. Histologic finding revealed decalcified dense bony tissue, the presence of lacunae, and normal osteocytes. Conclusion: Surgical removal is recommended when one or more of the following condition exist: interference with the construction of prosthesis, interference with oral function, irritation or pathology of the overlying tissue, inability of the patient to maintain proper oral hygiene, and fear of malignancy or other psychologic trauma. We report a rare case of the torus arising in hard palate with symptoms.

• Journal of Korea Water Resources Association
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• v.51 no.10
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• pp.895-903
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• 2018

There are a large number of weirs installed in rivers of Korea, and these characteristics are not common in other countries. When the flow passes through a structure such as a weir, discontinuous flow occurs. In terms of numerical simulation, it affects the numerical instability due to the balance between the flow term and the source term. In order to solve these problems, many researchers used empirical formulas or numerical scheme simplification. Recently, researches have been conducted to use more accurate numerical scheme. K-River was developed to reflect the characteristics of domestic rivers and calculate the discontinuous flow more accurately. For the verification of K-River, 1) numerical experiment simulations with a bump in the bed, 2) laboratory experiment of hydraulic jump simulation, 3) real river were performed. K-River verified its applicability by simulating results similar to the exact solution and observed value in all simulations.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.548-550
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• 2015

A 1-year-old female hedgehog was presented with subcutaneous mass in the right forelimb. Grossly, an elevated subcutaneous mass approximately 4 cm in diameter was located in forelimb. Central dark brown area was surrounded by peripheral milky white zone in the cut surface of mass. Histopathologically, numerous neoplastic cells formed irregular cords or sheets in dermis. Most of neoplastic cells showed palisading features to basement membrane with or without central caseous necrosis. These neoplastic cells showed invasive tendency to adjacent tissues. According to immunohistochemistry, the neoplastic cells demonstrated strong positive signals for pancytokeratin, and negative for vimentin. Based on the gross, histopathology and immunohistochemistry, this mass was diagnosed as basal cell carcinoma in a hedgehog.

• Korean Journal of Plant Tissue Culture
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• v.22 no.4
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• pp.189-194
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• 1995

Calli were successfully induced from immature embryos of Citrus junos SIEB. cultured on 1/2 MS medium supplemented with 40.4 BA. Plant were regenerated from immature embryo derived callus on MS medium with 5 $\mu$M BA. The calli were morphologically characterized by two types: one was whitish and the other was yellowish. After 16 weeks of culture, shoots and root were formed on calli. Plantlets were transplanted to soil and successfully grown to a whole plant Also, the arrangement of the cells showed many differences according to developmental stages of callus and organogenesis. The small cells were compact in callus cultured for 6 weeks and the extended cells which divided actively appeared in it after 8 weeks of culture. The globular protrusion of compacted cells occurred in callus after 10 weeks of culture, and the neighboring cells were liquefied. Oil sac surrounded by the liquefied cell was observed in the leaf and was formed by rupture of liquefied cells.

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.97-108
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• 2012

During the last few decades, the ever-increasing knowledge of coastal morphogenic processes has made marine terraces the most recognizable, widespread and scientifically reliable records to determine both qualitatively and quantitatively the vertical movements that have affected the tectonically active coastal regions during the Quaternary. This study first aims to address the marine terrace records from Suje-ri to Suryum-ri along the coast of Gyeongju, SE Korea. Eight distinct flights of terraces, including HH YC, elevated up to 160 m above present sea level have been mapped along the coast of the study areas, and are designated $L_{II}$ to HH YC from the youngest to oldest. Based on the elevation of paleo-shoreline and inferred formation age for HH YC uplift rate since the middle Pleistocene has been estimated at 0.23 mm/year. Establishing the nature and timing of the uplift history derived from marine terraces provide a better understanding of neotectonic framework for explain enigmatic, complex landscape evolution in the Korean peninsula.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.291-291
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• 2018

하천 및 수자원의 효율적인 관리와 더불어 다양한 수공구조물의 운영 및 관리를 위해서 구조물 주변에서 발생하는 불연속 흐름 및 급변류 등의 현상과 구조물 운영을 반영한 수치해석 기법을 이용한 모델 개발의 중요성이 커지고 있다. 본 연구에서는 하천의 불연속 흐름을 모의하기 위한 1차원 흐름해석 모형(K-River)을 개발하였다. 본 모형은 천이류와 급변류를 수치적으로 안정하게 처리하기 위하여 지배방정식을 보존형 Saint-Venant 방정식으로 선정하고, FVM과 Forward Euler 방법을 이용하여 이산화를 수행하였다. 수치흐름률을 계산하기 위해서 불규칙 단면과 하상의 급경사 등에 신뢰도가 높은 기법으로 판단되는 근사 Riemann해법 중 하나인 HLL flux를 이용하였다. 개발된 K-river 모형의 검증을 위해서 해석해가 존재하는 타원형의 하상융기가 있는 하도에 적용하였으며, 국내에서 하천 설계 및 관리를 위해서 광범위하게 이용되고 있는 1차원 흐름해석 모형인 FDM기반의 HEC-RAS 모의결과와 비교 검토를 수행하였다. 그 결과, FDM기법에서는 모의되지 않는 일부 급변류 패턴을 개발 모형을 통해 모의가능하였으며, 전체적으로 K-River가 기존 모형 보다 해석해에 근사한 결과를 나타내었다. 또한, 배수문을 비롯하여 합류부, 분류부, 펌프장, 암거 등이 설치되어 운영되고 있는 아라뱃길에 적용하여 K-River의 적용성을 평가하였다. K-River를 이용하여 아라뱃길의 흐름분석을 수행한 경우가 HEC-RAS를 이용한 경우보다 수위와 유량의 유동을 시간에 따라 세밀하게 모의하였으며, 이는 배수효과에 의한 파의 전달이 FDM기법 대비 정확히 모의되기 때문으로 판단된다. 추후 연구에서는 현재보다 시간간격을 상세화 하여 수집된 관측수위를 통해 추가적인 검증을 수행하고, 다양한 특성을 가진 타 하천 등에 적용하여 모형의 적용성을 확대하고자 한다.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.576-581
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• 2007

The purpose of this study is to investigate changes in the forearm-muscle fatigue of a train driver operating the MasCon by using EMG (electromyogram) measurement technique. Train drivers usually use their forearm 4hours/day for normal operation. Accordingly, few different EMG signals of deltoid, biceps brachii, brachioradialis, flexor carpi ulnaris muscle of upper extremity have been measured and analyzed. The raw EMG Signals have been converted into median frequency using spectrum analysis. As the result, 80% of 10 subjects (real train drivers) showed that median frequency value of all four muscles has been reduced after 30 minutes of train operation. This results demonstrated that operating MasCon for 30 minutes could induce muscle fatigue.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.73-79
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• 2018

In the west coast, south coast, and river basin, the use of geotextile mats has been increasing to improve the soft ground for making industrial facilities space and farmland. As an initial step to improve the vast and soft ground, the geotextile mats are laid and bonded to increase the bearing capacity of the wide ground for supporting construction equipment. Seam strength of geotextile mats exert a force only about 50% of the tensile strength of the fabric, which causes problems such as uplift and sinking in the soft ground. In this study, various types of geosynthetic matting techniques were investigated and the tensile strength of each method was compared and analyzed. Numerical analysis shows that stress increment in the ground due to the overburden load decreases when the seam strength of the geosynthetics mats is increased. When the seam strength was increased to 60, 70 and 80%, the bearing capacity of ground by geotextile mat was increased.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.2
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• pp.107-118
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• 2021

Due to the acceleration of road construction, the number and extension of tunnels are increasing every year. A lot of research has been done on the collapse of tunnels, but research on the invert heaving is insufficient. Therefore, in this study, a sensitivity analysis was performed using a geotechnical general-purpose program to analyze the effect of the invert curvature of a tunnel excavated on the soft ground. As a result, it was quantitatively confirmed that the stability of a tunnel was increased as the curvature of the tunnel invert was increased so that the safety factor was calculated to be large regardless of the ground conditions and the thickness of the support. In addition, it was confirmed that the stability of the tunnel was increased by reducing the convergence of the tunnel and the maximum bending stress supported by shotcrete. Therefore, when a tunnel is excavated on soft ground, it is believed that applying a curvature to the invert will increase the stability of the tunnel.

• Explosives and Blasting
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• v.38 no.4
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• pp.26-36
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• 2020

With the increase of expansion and use of the underground space, the possibility of an underground explosion by terrorists is increasing. In this study, after modeling a circular tunnel excavated at a depth of 50m, an explosion load was applied to the inside of the tunnel. As for the explosion load, the explosion load of the maximum explosive amount for six types of vehicle booms proposed by ATF (Bureau of Alcohol, Tobacco, and Firearms) was calculated. For the rock mass around the circular tunnel, three types of rock grades were selected according to the support pattern suggested in the domestic tunnel design. Nonlinear dynamic analysis was performed to evaluate the influence of the ground structure by examining the surface displacement using the explosion load and rock mass characteristics as parameters. As a result of the analysis, for grade 1 rock, the influence on the uplift of the surface should be considered, and for grade 2 and 3 rocks, the influence on a differential settlement should be considered. In particular, for grade 3 rocks, detailed analysis is required for ground-structure interaction within 40m. Also, it is considered that the influence of Young's modulus is the main factor for the surface displacement.