• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3643-3652
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• 2015

The aim of this study is to analyze the IAQ concentrations of school rooms. In this study we measured and characterized IAQ at 440 school rooms from May 2009 to November 2012. At some school rooms, the $PM_{10}$ concentrations exceeded the IAQ guidelines ($100{\mu}g/m^3$) of the Ministry of Education. $CO_2$ concentrations at high schools were 1.18 and 1.06 times higher than that of the elementary and middle schools, respectively. $CO_2$ concentrations of some school rooms were exceeded the IAQ guidelines (1,000 ppm). Moreover, TBC concentrations at elementary school rooms were 1.23 and 1.33 times higher than that of the middle schools and high schools, respectively. TBC and HCHO concentrations did not exceed the IAQ guidelines. The classroom/non-classroom ratio of $PM_{10}$ was 1.06, while that $CO_2$ was 1.04, HCHO was 0.62, and TBC was 1.16.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.476-483
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• 2021

Traumatic bone cyst (TBC) is an asymptomatic lesion seen most in adolescents. TBC is found incidentally on routine panoramic examinations and appears as a relatively well-demarcated unilocular radiolucency with scalloped margins. Histological examination reveals a vacant cavity of cancellous bone usually unlined or very occasionally lined with a thin connective tissue layer. The lack of lining epithelial membrane is common histological feature. The most affected site is between the mandibular canine and third molar. The involvement of the mandibular symphysis is rare. The etiopathogenesis of the TBC is unclear. TBC is treated with surgical exploration and curettage; new bone is formed in place of the lesion within 6 - 12 months of surgery. Diagnosis of TBC prior to surgical intervention has limitations in most of the cases. Both of our patients were diagnosed through radiological examination and biopsy. Neither patient had a history of trauma. After surgery, the panoramic radiograph and CBCT were used to confirm bone healing.

• 보건세계
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• v.37 no.10 s.410
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• pp.4-8
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• 1990

• 보건세계
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• v.37 no.9 s.409
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• pp.4-8
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• 1990

• 보건세계
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• v.37 no.7 s.407
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• pp.4-8
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• 1990

• 보건세계
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• v.37 no.8 s.408
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• pp.4-9
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• 1990

• 보건세계
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• v.37 no.11 s.411
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• pp.4-10
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• 1990

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.236-239
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• 2004

The ternary blended cement(TBC) which the ability of resistance for seawater, the effect of decreation of hydration heat of concrete and long-age strength are known to be superior to other types was used to derive the estimation function of 91-age strength, 28-age strength with 28-age strength, 7-age strength respectively by analyzing the characteristics of statistics of compressive strength. The sample specimens was made after testing the variations of slump, air-contents during 30 minutes for consideration of transportation period. The functions might be expected to be useful for construction smoothness and reasonable quality control of concrete with TBC.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.1
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• pp.15-20
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• 2014

Thermal barrier coating (TBC) is used to protect the substrate and extend the operating life of the gas turbine for a power plant and an aircraft. The major cause of failure of such a coating is the spallation of coating, and it results from the thermal stress between top coating and bond coating. To improve the durability of TBC system, the dense vertical cracked (DVC) coating method to insert vertical cracks is applied to a gas turbine blade. In this study, a criterion for the design of vertical crack in the DVC coating was presented using the finite element analysis.

• Proceedings of the Korean Society for Information Management Conference
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• 2005.08a
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• pp.357-364
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• 2005

저자동시인용 자료에 대한 분석 도구로 삼각매개중심성 (triangle betweenness centrality; TBC) 척도를 비롯하여 네 가지 새로운 척도를 제안하고 정보학 분야의 지적 구조 분석에 적용해보았다. 제안한 척도는 사회네트워크 분석 분야에서 사용되고 있는 여러 중심성 척도를 참고하여 동시인용 데이터에 적합하도륵 고안되었다. 검증을 위해서 이은숙, 정영미(2002)의 연구에서 수집한 1990년부터2000년까지 11년간 Journal of America Society for Information Science에 인용된 주요 저자50명의 동시인용 네트워크를 여러 중심성 척도를 사용해서 분석하였다. 전통적인 분석 도구인 다차원척도법이나 군집분석과 달리 중심성 척도를 통해서는 저작물에 반영된 개별 저자의 입지와 영향력에 대한 구체적인 분석이 가능하였다. 특히 삼각매개중심성 척도는 측정 범위의 조절이 자유로와서 지역적 중심성과 전역적 중심성을 모두 파악할 수 있는 것으로 나타났다.