• 대한치과교정학회지
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• 제42권5호
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• pp.235-241
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• 2012

Objective: The purpose of this study was to evaluate the validity of the 3-dimensional (3D) superimposition method of digital models in patients who received treatment with rapid maxillary expansion (RME) and maxillary protraction headgear. Methods: The material consisted of pre- and post-treatment maxillary dental casts and lateral cephalograms of 30 patients, who underwent RME and maxillary protraction headgear treatment. Digital models were superimposed using the palate as a reference area. The movement of the maxillary central incisor and the first molar was measured on superimposed cephalograms and 3D digital models. To determine whether any difference existed between the 2 measuring techniques, intra-class correlation (ICC) and Bland-Altman plots were analyzed. Results: The measurements on the 3D digital models and cephalograms showed a very high correlation in the antero-posterior direction (ICC, 0.956 for central incisor and 0.941 for first molar) and a moderate correlation in the vertical direction (ICC, 0.748 for central incisor and 0.717 for first molar). Conclusions: The 3D model superimposition method using the palate as a reference area is as clinically reliable for assessing antero-posterior tooth movement as cephalometric superimposition, even in cases treated with orthopedic appliances, such as RME and maxillary protraction headgear.

• 대한금속재료학회지
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• 제50권4호
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• pp.324-330
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• 2012

The microstructural changes of three pieces from an ancient iron pot were studied in order to identify present the material degradation due to repeated heating for one-thousand years. The microstructures of the pieces were divided into the areas of ferrite/graphite, ferrite/pearlite, and corroded oxidation. The area of ferrite/graphite was undergone by severe Galvanic corrosion, but that of ferrite/pearlite was not even during a thousand years' using. The shape of the graphites was coexisted with types of A, B, and C of as modern graphite classification. In the ferrite/pearlite area, abnormal acicula precipitates with a high aspect ratio of $0.2{\mu}m$ thickness and several hundreds ${\mu}m$ length were presented. They might be a kind of carbide in the ferrite matrix with its special precipitate plane.

• Imaging Science in Dentistry
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• 제40권4호
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• pp.159-163
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• 2010

Purpose : This retrospective study was performed to investigate the prevalence of the idiopathic osteosclerosis (IO) in Korean malocclusion patients according to age, sex, and the Angle's classification of malocclusion. Materials and Methods : This study consisted of 2,001 randomly selected patients from the Department of Orthodontics at the Gangneung-Wonju National University Dental Hospital, Korea. The prevalence of IO in Korean malocclusion patients was recorded using their panoramic radiographs, and the following parameters were surveyed; age, sex, and the Angle's classification of malocclusion. The chi-square test was analyzed to determine the statistical significance of differences in the prevalence of IO between age, sex, and the Angle's classification of malocclusion. Results : The prevalence of IO in the jaws was 6.7% in a total of 2,001 examined orthodontic patients. The majority of IO was found in the mandible (96.58%). The 30-39 age group showed the highest prevalence of IO (9.60%). There was a higher prevalence in females (6.89%) than in males (6.45%). The prevalence of IO in Angle Class I group (7.07%) was the most frequent, followed by Angle Class II group (6.72%), and Angle Class III group (6.40%). However, there was no statistical significance in sex and Angle's classification of malocclusion. Conclusion : The prevalence of IO in malocclusion patients showed the differences between various age groups and most of them were found in the mandibular posterior area. However, sex and the type of malocclusion are not to be considered as a contributing factor of IO.

• Restorative Dentistry and Endodontics
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• 제39권1호
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• pp.63-67
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• 2014

This is a case report of chronic maxillary sinusitis caused by root canal overfilling of Calcipex II (Techno-Dent). A 60 year-old male complained of dull pain in the right maxillary molar area after complicated endodontic treatment using Calcipex II paste and was finally diagnosed with a chronic maxillary sinusitis through a clinical and radiological observation. In the biopsy examination, the periapical granuloma contained a lot of dark and translucent Calcipex II granules which were not stained with hematoxylin and eosin. They were usually engulfed by macrophages but rarely resorbed, resulting in scattering and migrating into antral mucosa. Most of the Calcipex II granules were also accumulated in the cytoplasms of secretory columnar epithelial cells, and small amount of Calcipex II granules were gradually secreted into sinus lumen by exocytosis. However, chronic granulomatous inflammation occurred without the additional recruitment of polymorphonuclear leukocytes (PMNs) and lymphocytes, and many macrophages which engulfed the Calcipex II granules were finally destroyed in the processes of cellular apoptosis. It is presumed that Calcipex II granules are likely to have a causative role to induce the granulomatous foreign body inflammation in the periapical region, and subsequently to exacerbate the chronic maxillary sinusitis in this study.

• 대한치과교정학회지
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• 제48권4호
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• pp.262-267
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• 2018

The aim of this study was to test the clinical application of an intraoral scanner for serial evaluation of orthodontic tooth movement. The maxillary dentitions of eight patients with fixed orthodontic appliances were scanned using an intraoral scanner at the beginning of treatment (T0), and at 1 month (T1), 2 months (T2), 3 months (T3), and 4 months (T4) after T0. The serial digital models were superimposed on the palatal surface as a reference area, and the linear and angular changes of the central incisors, canines, and first molars were evaluated. The intraclass correlation coefficient and method errors showed that this method was clinically acceptable. Various types of orthodontic tooth movements, including minute movements, could be observed every month. The intraoral scanner and digital superimposition technique enabled the serial evaluation of orthodontic tooth movement without taking serial impressions and/or acquiring radiographs.

• Child Health Nursing Research
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• 제21권2호
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• pp.168-175
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• 2015

Purpose: The purpose of this study was to identify whether individualized distraction intervention using a smart phone affected pre-op anxiety of children. Methods: This was a nonequivalent control group pre-post test quasi-experimental design. The participants were 30 children in the experimental group and 30 in the control group. In experimental group, a smart phone individualized distraction intervention was given to children from the reception area to the operation room. Results: For heart rate, there were no statistically significant differences between the experimental group and control group. In the behavioral anxiety response, there were statistically significant differences between the experimental group and control group (t=-3.11, p=.003). Conclusion: The finding suggest that, for pre-op children, the individualized distraction intervention using a smart phone had some significance as a nursing intervention having a positive impact. Such interventions can help pediatric nurses to relieve pre-op anxiety and improve health of children in their care.

• 한국환경과학회지
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• 제26권7호
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• pp.837-846
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• 2017

This study aimed to investigate the dilapidated Fine View Square located in the city of Gangneung and analyze problems for building it into a sustainable space under an effective management plan. Further to creating an ecological base for restoring the natural circulation, a restorative method for the damaged area, a spatial assignment by the UNESCO's Man and Biosphere Programme (MAB), and an urban ecological park, we not only wanted to provide an environment that is citizen friendly, but also a practical and realizable project to connect with the various methods and programs mentioned above, while utilizing the Ministry of the Environment 's ecosystem conservation fund. In conclusion, we found that it would be possible to contribute to building an urban ecological park the Ministry of Environment proposed while restoring the lost natural circulation in Gyodong Square in the city of Gangneung and ecological soundness of the city along with the reduced heat island effect and the increased biological diversity and Ecological Soundness.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.70-79
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• 2013

In this paper, a comparative study on the frequency estimation methods using IRDWT (Improved Recursive Discrete Wavelet Transform), FRDWT(Fast Recursive Discrete Wavelet Transform), and GCDFT(Gain Compensator Discrete Fourier Transform) is presented. The 345[kV] power system modeling data of the Republic of Korea by EMTP-RV is used to evaluate the performance of the proposed two kinds of RDWT(IRDWT and FRDWT) and GCDFT. The simulation results show that the frequency estimation technique based on FRDWT could be the optimal frequency measurement method, and thus can be applied to FDR(Fault Disturbance Recorder) for wide-area blackout protection or frequency measurement apparatus.

• 한국지반공학회논문집
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• 제28권4호
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• pp.23-33
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• 2012

최근 들어 집중호우 및 태풍과 국지성 집중호우로 인한 산사태 피해가 자주 보고되고 있다. 국내 지형특성상 산지 인근에서 도시가 발달되고 도로 철도 등의 기간시설물이 건설된 경우가 많기 때문에 산사태로 인한 인명 및 재산피해는 매우 심각하다. 이러한 피해를 효과적으로 방지하기 위해서는 건설계획 단계부터 산사태 위험이 높은 지역을 파악하고 적절한 대책을 마련하는 것이 중요하다. 본 연구에서는 산사태 발생에 영향을 미칠 수 있는 지형학적 특성, 토질의 특성, 강우 정보, 나무의 종류 정보 등의 자료를 재해대장 분석, 항공사진 분석, 현장조사를 실시하여 구축한 423 지점의 산사태 데이터에 대한 통계학적 분석을 수행하여 산사태 위험도 예측식을 제안하였다. 제안된 예측식으로 예측된 결과와 실제 산사태 발생여부를 비교해 본 결과 약 92%의 분류 정확도를 보였다. 예측식에 필요한 입력치들은 단 시간 내에 저비용으로 획득할 수 있도록 구성하였다. 또한 예측결과의 경우 재해지도 형식으로 표현하기 용이하기 때문에 제안된 산사태 위험도 예측식은 광범위한 지역의 산사태 발생 위험도를 산정하는데 효과적으로 활용될 수 있다고 판단된다.

• 한국지구과학회지
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• 제34권2호
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• pp.120-135
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• 2013

강릉항 주변 해역의 퇴적환경의 변화 특성을 파악하기 위해 2007년 2월부터 2009년 2월까지 총 5회에 걸쳐 획득한 퇴적물의 조직변수와 측량 자료를 분석하였다. 연구지역의 퇴적물은 주로 모래로 이루어져 있고 외해 방향으로 갈수록 입도가 세립해진다. 하계에 평균입경은 외해역, 강릉항 내측, 남항진 해빈에서 동계보다 조립하게 나타났으며, 안목 해빈에서는 점차적으로 세립해지는 양상을 나타냈다. 강릉항 완공 전의 연구 결과와 비교할 때, 강릉항 완공 후 평균입경은 안목 해빈에서 세립해졌으나, 남항진 해빈에서 조립해졌다. 2년간의 침 퇴적 양상을 보면, 수심 5-10 m 사이 지역에서는 침식이, 수심 2-5 m 사이 지역에서는 퇴적이 우세하며, 수심이 2 m 보다 얕은 지역에서는 침식과 퇴적이 교호하는 형태로 침식이 다소 우세하게 나타났다. 연구지역의 퇴적물 조직변수와 침 퇴적 분포는 지속적으로 변화하고 있다. 이러한 변화는 계절적인 변동뿐만 아니라 장기변화 추이 양상을 보이고 있고, 강릉항 완공 후 장기변화 추이는 유지되는 것으로 생각된다.