• Journal of Korean Neurosurgical Society
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• 제59권3호
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• pp.242-246
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• 2016

Craniosynostosis is the premature fusion of calvarial sutures, resulting in deformed craniofacial appearance. Hence, for a long time, it has been considered an aesthetic disorder. Fused sutures restrict growth adjacent to the suture, but compensatory skull growth occurs to accommodate the growing brain. The primary goal for the management of this craniofacial deformity has been to release the constricted skull and reform the distorted shape of the skull vault. However, the intellectual and behavioral prognosis of affected children has also been taken into consideration since the beginning of the modern era of surgical management of craniosynostosis. A growing body of literature indicates that extensive surgery, such as the whole-vault cranioplasty approach, would result in better outcomes. In addition, the age at treatment is becoming a major concern for optimal outcome in terms of cosmetic results as well as neurodevelopment. This review will discuss major concerns regarding neurodevelopmental issues and related factors.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.89-92
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• 2005

Recently there have been occurred many loss of life and extensive damage to social infrastructures due to moderate and strong earthquakes all over the world. In this research, major design factors have been evaluated for the establishment of the rational seismic design code of rectangular RC bridge piers. It was concluded from this study that the axial force ratio and the longitudinal steel ratio should be the most important influencing design parameter for the seismic displacement ductility. However those parameters are not considered in the confinement steel ratio of the KHBDS. Thus, the objective of this study is to propose a rational design equation for transverse reinforcements of rectangular RC bridge piers. New confinement steel ratio is proposed by introducing the effect of the axial force and the longitudinal steel to the current KHBDS. It is thought that these new codes could release the rebar congestion problem in the plastic hinge region of RC bridge piers which contribute to the enhancement of constructibility and economization for RC bridge construction.

• 한국임상약학회지
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• 제6권2호
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• pp.24-27
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• 1996

In order to determine whether there was a clinically sufficient amount of drug remaining in used fentanyl patches, quantitative analysis of two different types of patches, each containing 2.5 mg (n=36) and 5 mg (n=20) was performed. After being used for approximately 72 hours by patients with cancer, each patch was put in the plastic bag and stored at $4^{\circ}C$ until analysis. Fentanyl remaining in patches was extracted with 50 ml methanol, diluted with water, and counted twice in a $\gamma-Counter$ (expressed as CPM). Patches that originally contained 2.5 mg and 5 mg of fentanyl were shown to have $0.48{\sim}1.86\;mg\;(mean:\;1.03\;mg,\;41.16\%)\;and\;0.37{\sim}3.95\;mg\;(mean:\;2.37\;mg,\;47.33\%)$ after use, respectively. A wide interpatient variability was observed in the rate of fentanyl release from patches although the application period was standardized to 72 hours. Since a significant amount of drug remained in the discarded patches, it is highly recommended that patients dispose used ones under supervision to prevent abuse or misuse of the narcotic drug.

• 한국해양공학회지
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• 제10권4호
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• pp.75-83
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• 1996

Polymeric composites can be subjected to a wide variety of environmemtal conditions in practical use. One of most important conditions to be considered in the stuctural design using such materials is the miisture envirnment. Thus the moisture effect on interlaminar fracture toughness $G_IC$ and $G_IIC$ of CFRP(carbon fiber reinforced plastic) composed of carbon fibers and epoxy resin is studied in this paper. Specimens were first processed in 25, 50, $80^{\circ}C$ flesh water and $25^{\circ}C$ sea water for various periods of time. After that, the water absorption and fracture toughness tests were performed under laboratory atmosphere. As result, the specimen processed in $80^{\circ}C$ flesh water indicates the highest misture absorbing capability, the second in $50^{\circ}C$ flesh water, the third in $25^{\circ}C$ sea water, and the specimen in $25^{\circ}C$ flesh water does the lowest. The interlaminar fracture toughness $G_IC$ increases, approaches to the maximum, and decreases as the immersion time increases. In case of interlaminar $G_IIC$, the value of the specimen processed in $80^{\circ}C$ flesh water turns out to be higher than others. In addition, the scanning electron micrographs(SEM) of fracture surfaces were also examined in order to explain the mechanism of fracture.

• 한국지반공학회논문집
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• 제20권6호
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• pp.5-10
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• 2004

일반적으로 일차원 압밀상태에 있는 정지토압계수 $K_0$값은 삼축시험에서 구해지지만, 압밀중의 간극수의 흐름이 방사류이고, 공시체의 변형이 3차원적이므로, 얻어진 값의 신뢰성에는 의문이 있다. 여기서는, 일차원 압밀시험기를 개량하여, 압밀링 중앙높이에 배치한 압밀링 요소를 토압감지부로 하며, 감지부 중앙에서는 간극수압을 측정하였다. 내경 6cm의 압밀링은 부동(浮動)링 형식으로 높이 4cm의 공시체 중앙높이가 항상 같은 위치를 유지하는 구조이다. 직경 6cm의 공시체와 샘플링후 시료변형을 고려한 압밀링 내경보다 직경이 약간 작은 공시체에서 얻은 압밀종료시의 $K_0$값은 공시체직경과 압밀압력에 상관없이 거의 0.5를 나타내었다.

• 한국표면공학회지
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• 제32권6호
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• pp.647-657
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• 1999

Due to the inherently poor adhesion strength of Cu-based leadframe/EMC (Epoxy Molding Compound) interface, popcorn cracking of thin plastic packages frequently occurs during the solder reflow process. In the present work, in order to enhance the adhesion strength of Cu-based leadframe/EMC interface, black-oxide layer was formed on the leadframe surface by chemical oxidation of leadframe, and then oxidized leadframe sheets were molded with EMC and machined to form SDCB (Sandwiched Double-Cantilever Beam) and SBN (Sandwiched Brazil-Nut) specimens. SDCB and SBN specimens were designed to measure the adhesion strength between leadframe and EMC in terms of critical energy-release rate under quasi-Mode I ($G_{IC}$ ) and mixed Mode loading ($G_{C}$ /) conditions, respectively. Results showed that black-oxide treatment of Cu-based leadframe initially introduced pebble-like X$C_2$O crystals with smooth facets on its surface, and after the full growth of $Cu_2$O layer, acicular CuO crystals were formed atop of the $Cu_2$O layer. According to the result of SDCB test, $Cu_2$O crystals on the leadframe surface did not increase ($G_{IC}$), however, acicular CuO crystals on the $Cu_2$O layer enhanced $G_{IC}$ considerably. The main reason for the adhesion improvement seems to be associated with the adhesion of CuO to EMC by mechanical interlocking mechanism. On the other hand, as the Mode II component increased, $G_{C}$ was increased, and when the phase angle was -34$^{\circ}$, crack Kinking into EMC was occured.d.

• 전기학회논문지P
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• 제56권4호
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• pp.195-200
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• 2007

This paper describes the countermeasures for preventing the electric shock which can be occurred in the low-voltage handhole underwater. Low-voltage handholes were designed and made for the test in the testing field. Which were installed 4 cases. a metal handhole cover was employed in case 1; FRP(Fiber glass Reinforced Plastic) handhole cover in case 2; an insulated rubber was put on the joint of the cables in case 3; the exposed conductors(cover, frame etc) were commoned and grounded in case 4. Thus, an ground potential near the low-voltage handhole was measured and evaluated quantitatively for the 4 cases. The measured results show that the potential of case 2.3 were lower than that of case 1 because the insulated rubber and the FRP cover prevented direct contact to the fault point. The case 4 is the lowest among the 4 cases because the common and grounding helps the fault current release into the ground, which makes the ground potential rise lower. As a result, although each case has the defects, these ways can effectively lower the electric shock risk in the low-voltage handhole.

• 동력기계공학회지
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• 제18권6호
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• pp.166-173
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• 2014

In this study, a laminated composite material with dispersing aluminum oxide powder between the CFRP laminate plies, and also CFRP composites without aluminium oxide powder were fabricated for Mode I experiments using the DCB specimen and a tensile test. The behavior of the crack and the change of the interfacial fracture toughness were evaluated. Also in order to evaluate the damage mechanism for the crack extension, the AE sensor on the surface of the DCB test specimen was attached. AE amplitude was estimated for CFRP-alumina and CFRP composite. And the fracture toughness was evaluated by the stress intensity factor and energy release rate. The results showed that an unstable crack was propagated rapidly in CFRP composite specimen along with the interface, but crack propagation in CFRP-alumina specimen was relatively stable. From results, we show that aluminium oxide powder spreaded uniformly in the interface of the CFRP laminate carried out the role for preventing the sudden crack growth.

• 한국추진공학회지
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• 제22권4호
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• pp.55-60
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• 2018

열적 특성은 에너지 물질 분야에서 중요한 특성 중 하나로, 분해열을 방출하기 때문에, 열적 특성 분석에 DSC(Differential Scanning Calorimetry)가 자주 사용된다. 그러나 DSC 측정의 경우, 용융과 같은 열역학적 변화가 kinetics 분석에 방해를 끼친다. 이번 연구에서는 이 문제점을 해결하는 방안으로, 등온 조건으로 한 DSC 기초 데이터와 g 단위로 측정하는 ARC(Accelerating Rate Calorimetry)의 데이터를 이용하여 AKTS(Advanced Kinetics and Technology Solutions) thermokinetic 프로그램을 이용하여 열적 노화 특성을 예측, 비교한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권3호
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• pp.263-269
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• 2001

하순 및 하악골 정중열은 매우 드문 선천성 기형으로 , 하순절흔에서부터 하악은 물론 경부, 흉부까지 연장되어 다양하게 나타날 수 있으며, 원인은 확실하지 않으나 정중부로의 중배엽의 침투 실패, 하악돌기의 유합부전 그리고 외부 요인들이 논의되고 있다. 치료방법 및 시기에 관해서는 임상소견이 다양하고 증례가 드물기 때문에 많은 논란이 있어왔다. 그러나 현재의 경향은 연조직 기형은 연하 및 발음의 기능적 장애를 예방하기 위하여 가능한 조기에 치료하며, 악골고정을 위한 강선 결찰 혹은 골이식술은 사춘기 후로 미루는 추세이다. 본 교실에서는 저작 장애를 주소로 내원한 8세 여자 환자의 임상소견에서 하악골 정중열과 하순의 수술로 인한 반흔조직 및 하순에서부터 치조골을 가로지르는 섬유성 소대 등을 발견할 수 있었으며, 하악의 정중열을 장골 이식을 이용 하여 양호한 결과를 얻을 수 있었으며, 추후 하순과 순. 설측 전정의 연조직 기형은 심미성과 기능 향상을 위해 부가적인 술식이 필요하리라 생각된다.