• 한국지진공학회논문집
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• 제9권2호통권42호
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• pp.29-36
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• 2005

이 연구의 목적은 소성힌지영역에서 비부착 주철근을 갖는 철근콘크리트 교각의 비탄성 거동을 파악하는데 있다. 사용된 프로그램은 철근콘크리트 구조물의 해석을 위한 RCAHEST이다. 재료적 비선형성에 대해서는 균열콘크리트에 대한 인장, 압축, 전단모델과 콘크리트 속에 있는 철근모델을 조합하여 고려하였다. 이에 대한 콘크리트의 균열모델로서는 분산균열모델을 사용하였다. 또한 소성힌지영역에서 비부착 주철근에 의한 영향을 고려하였다. 이 연구에서는 소성힌지영역에서 비부착 주철근을 갖는 철근콘트리트 교각의 비탄성 거동의 파악을 위해 제안한 해석기법을 신뢰성 있는 연구자의 실험결과와 비교하여 그 타당성을 검증하였다.

• 대한두개안면성형외과학회지
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• 제24권2호
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• pp.66-72
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• 2023

Background: During the coronavirus disease 2019 (COVID-19) pandemic, the everyday use of face masks massively increased to prevent the spread of infection. Many people complain of ear pain and erosion when wearing a mask for extended periods of time. If prolonged mask usage is uncomfortable for ordinary people, a question arises-how much more inconvenient must mask wearing be for patients with a full-thickness skin graft (FTSG) donor site in the retroauricular region? Herein, we evaluated complications related to face mask use in 27 patients with a retroauricular FTSG donor site, with the goal of clarifying whether the retroauricular region is still an appropriate FTSG donor site in the context of the COVID-19 pandemic. Methods: Complications in 27 patients treated by FTSGs harvested from the retroauricular region from 2019 to 2021 were investigated. A questionnaire comparing the normal and the operated sides was administered. Pain, itching, soreness, deformity, and symmetry were further investigated. Results: Pain and itching were the only observed complications. The operated side was slightly more painful than the normal side in four patients (14.8%), and four patients (14.8%) reported itching on the operated side. However, all patients who experienced complications stated that the pain or itching did not interfere with mask wearing. Most symptomatic patients were older than 60 years of age (23.8%, p= 0.185) and wore masks for longer periods of time (28.5%, p= 0.326). Conclusion: Few retroauricular donor site-related complications occurred, and none of these complications caused inconvenience in daily life. Therefore, in the COVID-19 pandemic, the use of the retroauricular region as an FTSG donor site remains appropriate.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.770-772
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• 2005

Nodular fasciitis is an unusual benign tumor which is composed of myofibroblast. Typical histologic findings include haphazardly arranged pleomorphic arranged spindle cells in a myxoid stroma. These lesions may easily be misinterpreted as malignancy clinically and histologically because it presents as a rapidly growing mass from subcutaneous or deep fascia. These lesions are usually located over upper extremity and rarely in the head and neck region. It's important to emphasize the need of clinical suspicion and accurate histopathology of this rare benign lesion usually misdiagnosed as a malignacy to avoid unnecessary and inappropriate aggressive wide resection, when encountering subcutaneous nodules of the face and neck region. In this article, we report a rare case of Nodular fasciitis on the Nose and some reviews of the literature.

• 대한두개안면성형외과학회지
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• 제22권5호
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• pp.276-279
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• 2021

A 65-year-old woman presented with a solid mass on the right temporal area. The mass had grown for over 2 years without any initiating event of trauma or inflammation. Before excision, the patient went through a computed tomography scan, revealing a calcified mass without bony connection. Under general anesthesia, an excisional biopsy was performed. Microscopic examination confirmed a diagnosis of soft tissue osteoma. Soft tissue osteoma is rare, especially in the head and neck region. Osteomas in the temporal region have not been reported yet. Due to its rarity, osteoma might be misdiagnosed as another soft tissue or bone origin tumor. Its treatment of choice is simple excision. In this review, we present an unusual clinical form of soft tissue osteoma.

• 대한두개안면성형외과학회지
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• 제23권5호
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• pp.237-240
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• 2022

A 67-year-old man visited our plastic surgery clinic complaining of a palpable protruding mass (2.0×2.5 cm) in the right occipital region. To establish an appropriate treatment plan for the cystic mass, brain magnetic resonance imaging was performed. A 2.2 cm nodular lesion with peripheral enhancement in the right occipital region of the scalp was confirmed. In addition, two rim-enhancing nodular lesions up to 9 mm with marked perilesional edema in the right frontal lobe were confirmed. The findings suggested metastasis from cancer. After further evaluations, a mass in the right lower lung field was identified as adenocarcinoma of the lung. Histological examination characterized the excised lesion as a cutaneous metastasis from lung adenocarcinoma. This case report shows that a cystic mass, which commonly occurs in the scalp, may indicate lung cancer. In particular, if a cystic mass of the scalp is identified in a person at high risk for lung cancer, appropriate evaluation and urgent treatment should be performed.

• Archives of Plastic Surgery
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• 제45권3호
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• pp.214-221
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• 2018

Clarification is needed regarding the definitions and classification of groove and hollowness of the infraorbital region depending on the cause, anatomical characteristics, and appearance. Grooves in the infraorbital region can be classified as nasojugal grooves (or folds), tear trough deformities, and palpebromalar grooves; these can be differentiated based on anatomical characteristics. They are caused by the herniation of intraorbital fat, atrophy of the skin and subcutaneous fat, contraction of the orbital part of the orbicularis oculi muscle or squinting, and malar bone resorption. Safe and successful treatment requires an optimal choice of filler and treatment method. The choice between a cannula and needle depends on various factors; a needle is better for injections into a subdermal area in a relatively safe plane, while a cannula is recommended for avoiding vascular compromise when injecting filler into a deep fat layer and releasing fibrotic ligamentous structures. The injection of a soft-tissue filler into the subcutaneous fat tissue is recommended for treating mild indentations around the orbital rim and nasojugal region. Reducing the tethering effect of ligamentous structures by undermining using a cannula prior to the filler injection is recommended for treating relatively deep and fine indentations. The treatment of mild prolapse of the intraorbital septal fat or broad flattening of the infraorbital region can be improved by restoring the volume deficiency using a relatively firm filler.

• 대한두개안면성형외과학회지
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• 제25권3호
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• pp.133-140
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• 2024

Background: The medial canthal region features a complex three-dimensional and internal anatomical structure. When reconstructing a defect in this area, it is crucial to consider both functional and aesthetic aspects, which presents significant challenges. Generally, local flaps are preferred for reconstruction; however, skin grafts can be used when local flaps are not feasible. Therefore, we conducted a comparative analysis of surgical outcomes skin grafts when local flaps were not feasible, to determine which surgical method is more effective for medial canthal region reconstruction. Methods: Twenty-five patients who underwent medial canthal region reconstruction using skin grafts or local flaps from 2002 to 2021 were enrolled. Patient information was obtained from medical records. Five plastic surgeons evaluated the surgical outcomes based on general appearance, color, contour, and symmetry. Results: Skin grafts were used in eight patients and local flaps were used in 13. Combined reconstructions were employed in four cases. Minor complications arose in four cases but improved with conservative treatment. No major complications were reported. Recurrence of the skin cancer was noted in two cases. All categories showed higher scores for the local flap compared to both skin graft and combined reconstruction; however, the differences were not statistically significant respectively. Conclusion: The choice of appropriate surgical methods for reconstructing defects in the medial canthal region depends on various factors, including the patient's overall health, the size and depth of the defect, and the degree of involvement of surrounding structures. When a local flap is not feasible, a skin graft may provide favorable surgical outcomes. Therefore, a skin graft can serve as a viable alternative for reconstructing the medial canthal region.

• 한국농공학회논문집
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• 제51권6호
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• pp.17-23
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• 2009

The Soil and Water Assessment Tool (SWAT) model was used in this study to evaluate the hydrologic impacts by the impervious surface change in the farm region. The model was calibrated and validated by using four years (1999-2002) of measured data for the Gyeongancheon watershed in Korea. The simulation results agreed well with observed values during the calibration and validation periods. Land use scenarios including various changes of the plastic film house area in the farm region were applied to assess their effects on watershed hydrology. The results indicated that the surface direct (5.6%~14.0%) and total runoff (0.8%~1.5%) increased, but the groundwater discharge (10.7%~27.7%) and evapotranspiration (1.5%~3.3%) decreased as the plastic film house area (5.7%~12.4%) increased.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.97-100
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• 2005

It has been known that lab splices of the longitudinal reinforcement steel in bridge columns are not desirable for seismic performance, but it is sometimes unavoidable. Lap splices were usually be located in the plastic hinge region of most bridge columns that were constructed before the adoption of the seismic design provision of Korea Bridge Design Specification on 1992. This research is to evaluate the seismic performance of reinforced concrete bridge piers with lap splicing of longitudinal reinforcement in the plastic hinge region, and to develop the enhancement scheme of their seismic capacity by retrofitting with steel bands. It was observed that RC bridge specimens with lap-spliced longitudinal steels appeared to fail at low curvature and displacement ductility, but significant improvement was appeared in the ductility of RC specimens with steel bands retrofitted around the plastic hinge region.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.505-511
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• 2003

Experimental investigation was conducted into the flexure/shear-critical behavior of earthquake-damaged reinforced concrete columns with lap splicing of longitudinal reinforcement in the plastic hinge region. Six test specimens in the aspect ratio of 2,5 were made with test parameters: confinement ratios, lap splices, and retrofitting FRP materials. They were damaged under series of artificial earthquakes of which magnitude could be compatible in Korean peninsula. Directly after the pseudo-dynamic test, damaged columns were retested under inelastic reversal cyclic loading simultaneously under a constant axial load, P=$0.1f_{ck}A_g. Residual seismic performance of damaged columns was evaluated and compared to that of the corresponding original columns. Test results show that RC bridge piers with lap-spliced longitudinal steels in the plastic hinge region appeared to fail at low ductility. This was due to the debonding of the lap splice, which resulted from insufficient development of the longitudinal steels. The specimens externally wrapped with composite FRP straps in the potential plastic hinge region indicated significant improvement both in flexural strength and displacement ductility, and strain energy ductility.