• Nuclear Engineering and Technology
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• v.18 no.3
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• pp.200-208
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• 1986

The loss of coolant accident based on a double-ended cold leg break is analyzed with the discharge coefficient (Ca) of 0.4. This analysis covers the whole transient period from the start of depressurization to the complete refilling of the core by using RELAP4/MOD6-EM and RELAP4/ MOD6-HOT CHANNEL for the system thermal-hydraulics and the fuel performance during the blowdown phase respectively, and RELAP4/MOD6-FLOOD and TOODEE2 during the reflood phase. A simple analytical method has been developed to account for the lower plenum filling by approximating steam-water countercurrent flows and superheated wall effects at the downcomer during the refill period. Based on the informations. at the time of EOB (end-of-bypass), the refill duration time and the initial reflooding temperature were estimated and compared with the results from the RELAP4/MOD6, resulting in a good agreement. In addition, some parametric studies on the EOB were performed. The form loss coefficient between upper head and upper downcomer was found to be sensitive to the occurrence of the spurious EOB. Appropriate form loss coefficients should be taken into account to avoid the flow oscillations at the downcomer. The analyses with the six and three volume core nodalizations, respectively, show much similar trends in the system thermal-hydraulic performance, but the former case is recommended to obtain good results.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.186-194
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• 1997

The three child patients aged 3 to 5 years were worn by anterior space maintainer which are fixed type after missing of anterior teeth due to nursing caries, and were taken periodic follow check up. The results are : 1. At missing of anterior teeth, fixed space maintainer can be used. 2. Increased esthetic satisfaction and positive change of social behavior can be observed by these child patients. 3. Some phonations can be changed definitely after wearing the fixed space maintainer.

• The Journal of the Korean dental association
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• v.25 no.10 s.221
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• pp.913-916
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• 1987

저작운동을 중추신경계와 말초조직의 작용에의해 일생동안 학습과 적응의 가정을 통해 이루어진다. 저작의 양상은 유치가 구강내에 맹출되면서 이루어지며, 상하악 치아의 접촉, 점막과 혀 및 치아상호간에 일어나는 접촉과 치근막의 고유수용기와 악관절 수용기등에 의해 조정되어 최종적으로 에너지소비가 적고 동통이나 불편함이 없이 최대의 효율을 나타내는 양상으로 된다. 그러나 원활한 저작과 하악은동을 이룩하기 위해서는 저작근, 악관절, 상하악 치아의 교합등이 서로 조화를 이루어야 한다. 만일 외상에 의해 악관절의 기능장애가 오면 저작근활동이 변화하고 이에따라 교합장애를 야기한다. 또한 치아를 상실하거나 대합치아간의 조기접촉이 있으면 교합장애가 원인이 되어 근육활동이 변화와 악관절 기능장애를 초래한다. 그리고 때로는 지나친 근육의 활동(이갈이, 지속적 긴장성 수축)에 의해 지나친 치아의 마모로인한 교합장애나 악관절장애를 일으킬 수 있다. 따라서 하악의 기능을 충분히 이해하기 위해서는 교합의 형태학적 관계와 더불어 저작계의 기능적인 면도 고려하여 그 상호관계를 검토하여야 하며 본문에서는 교합에 관련된 저작근의 작용과 이에 영향을 주는 요인 및 교합장애와 근육활동장애의 연관성에 관해 고찰코자 한다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.56-56
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• 2018

토마토에서 과형은 과실의 여러 가지 형질 중에서 눈에 가장 잘 띄는 형질이며, 소비자의 토마토를 구매를 결정하는데 많은 영향을 미치는 중요한 형질이다. 토마토의 과형을 결정하는 여러 가지 유전자 중에 OVATE는 둥근 토마토 과일을 서양 배 모양(pear shape)의 과일로 전환하는데 결정적인 역할을 하는 유전자이다. OVATE 유전자에 의해서 과일의 모양이 변하는 것은 조기종결 코돈을 초래하는 열성 돌연변이에 의해서 유도되며, 단백질의 C-말단 영역이 제거됨에 따라 그 기능을 상실하여 나타나는 현상이다. OVATE 유전자는 주로 식물의 생식기관에서 발현되며, 꽃에서는 개악하기 10일전부터부터 전사체가 만들어지고 발달중인 과실에서는 개약 후 8일까지 전사체를 확인할 수 있다. 토마토 분자육종 과정에서 과형 판별을 위해서 OVATE 유전자 연관 분자표지는 보고된 바 있으나 OVATE 유전자 유래 분자표지는 보고된바가 없다. 본 연구에서 국내에서 육성된 육종 라인들의 resequencing을 통해 OVATE 유전자 염기서열간의 SNP를 발견하고 이들을 dCAPS 마커로 전환하여 분자표지를 개발했다. 이러한 분자표지는 둥근 토마토(round)와 서양 배모양(pear shape)토마토 육종 프로그램의 효율성과 정확성을 향상시키는데 활용할 수 있을 것으로 기대한다.

• KDI Journal of Economic Policy
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• v.11 no.4
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• pp.109-125
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• 1989

사회보험(Social Insurance)은 노령(老齡) 등 미래(未來)에 확실(確實)히 발생(發生)할 사안(事案)뿐 아니라 질병 등 불확실(不確實)한 사안(事案)에 의한 소득(所得)의 상실(喪失)을 보상하기 위한 보험(保險)의 역할을 한다. 대부분의 사회보험연구는 이 불확실성(不確實性)이 배제된 모형의 분석을 하고 있는데 본고(本稿)에서는 그러한 불확실성(不確實性)이 존재(存在)할 때 사회보험이 개인의 은퇴시기 결정에 미치는 영향을 분석하였다. 사회보험은 노동기(勞動期)로부터 은퇴기(隱退期)로의 소득이전(所得移轉)일 뿐 아니라 일을 할 수 있는 상태로부터 질병 등의 불확실한 사안(事案)에 의해 초래된, 일을 할 수 없는 상태로의 소득이전(所得移轉)도 된다. 이 두 번째의 역할 때문에 사회보험은 개인(個人)의 은퇴시기(隱退時期)를 늦추는 효과를 보일 수 있다. 특히 사회적 최선적정은퇴시기(最善適正隱退時期)(first best optimum)는 사회보험이 전혀 없는 경우의 은퇴시기가 보다 늦다. 반면 어느 일정(一定)한 시점(時點) 이후에만 사회보험(社會保險)의 수혜(受惠)가 가능(可能)하다면 이는 오히려 조기은퇴(早期隱退)를 초래(招來)하게 된다는 것을 보였다.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.497-504
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• 2010

The treatment of Class II non-extraction cases, especially when premolar space is lost due to premature loss of the deciduous molars, usually requires distal movement of the maxillary molars. The Jones jig appliance is a non-compliant intraoral appliance and is effective for the distalization of the maxillary molars. It has unfavorable side-effects, however, so caution is needed to adjust the appliance and select appropriate cases. We reported four cases in which maxillary molar distalizations were concomitant with the alignment of palatally erupted premolars.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.475-480
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• 2009

An infraoccluded tooth is a tooth that has failed to erupt to be in line with adjacent teeth in the vertical plane of occlusion. Multiple complications can occur as a result of an infraoccluded tooth. Tipping of neighboring teeth, loss of space opposing teeth elongation, increased susceptibility to dental caries and abnormal eruption path, impaction and rotation of permanent successor are the consequences of infraocclusion of primary molar. Therefore, early diagnosis and treatment is the key to prevent the complications. Treatment options can be periodic follow-up, temporary restoration or extraction of the infraoccluded tooth depending on the presence of the successor, the extent of infraocclusion and the extent of tilting of the neighboring teeth. The infraoccluded primary molars with permanent successors present tend to exfoliate normally. However, failure to do periodic check up of the infraoccluded teeth may lead to serious complications. In these cases, surgical extractions are often necessary after space regaining and space maintainers should be placed until the eruption of the permanent successors are completed.

• Nuclear Engineering and Technology
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• v.24 no.3
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• pp.243-251
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• 1992

Behavior of loop seal formation and clearing during small break loss of coolant accident is investigated using the RELAP5/MOD 2 and /MOD3 codes with the test of SB-CL-18 of the LSIF (Large Scale Test Facility）. The present study examines the thermal-hydraulic mechanisms responsible for early core uncovery including the manometric effect due to an asymmetric coolant holdup in the steam generator upflow and downflow side. The analysis with the RELAP5/MOD2 demonstrates the main phenomena occuring in the depressurization transient including the loop seal formation and clearing with sufficient accuracy. Nevertheless, several differences regarding the evolution of phenomena and their timing have been pointed out in かe base calculations. The RELAP5/MOD3 predicts overall phenomena, particularly the steam generator liquid holdup better than the RELAP5/MOD2. The nodalization study in the components of the steam generator U-tubes and the cross-over legs wiか the RELAP5/MOD3 results in good prediction of the loop seal clearing phenomena and their timing.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.729-733
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• 2004

Tooth avulsion usually causes inflammatory root resorption and ankylosis, and ankylosis cause severe functional and esthetic problems, especially in childhood. A 7-year-old female visited the Dept. of Pediatric Dentistry, Yonsei University with the chief complaint of avulsive trauma to the upper right incisor which was left dry for 40 minutes. Tooth was irrigated with saline and replanted immediately and splinted. Anti bacterial agent and anti inflammatory agent were prescribed. After 4 months of replantation slight external root resorption and apical radiolucency was seen at radiographic examination, therfore pulp extirpation and calcium hydroxide($Vitapex^{TM}$) canal filling were carried out. After 16 months, root canal was filled with gutta-percha, and bleaching treatment was done. Treatment results were satisfactory both esthetically and functionally for 8 years and 5 months.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.665-670
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• 2004

The mandibular buccal frenum becomes a problem when its attachment is too close to the marginal gingival. Heavy buccal frenum mucogingivally results in insufficient attached gingiva, inadequate vestibular depth and also difficulty in eruption of mandibular premolar. The aim of this study is to demonstrate the effectiveness of apically positioned partial-thickness flap as adequate method in order to remove heavy buccal frenum and expose impacted teeth. The author presents the case of a 12-year-old boy. He had problems that was prolonged eruption of #34, #35 due to high pull buccal frenum. After space regaining for normal eruption of #34, #35, we performed apically positioned partial-thickness flap on #34, 35 area. As a results, we confirmed that eruption of #34, #35 has been processed normally And vestibular depth, position of buccal frenum and width of attached gingival was within a normal range. Decrease in muscle pull, adequate width of attached gingiva and increased vestibular depth can be expected from this treatment.