• Restorative Dentistry and Endodontics
• /
• 제28권1호
• /
• pp.64-71
• /
• 2003

The purpose of this study was to compare the initial apical file(IAF) first Ole that fits to the apex in each canal before and after early flaring to analyze if the size of file to fit to the apex would increase after flaring. Eighty anterior teeth with complete apical formation and patent foramens were selected. The samples were randomly divided into 4 groups(GG, OS, GT, PT Group) of 20 teeth each. A file was fit to the apex in each canal and that size recorded. Radicular flaring were completed using different types of instruments. After flaring a file was again fit to the apex in the same manner as before and its size recorded. The results of this study were as follows : 1. The mean diameter of IAF before flaring(file diameters in $mm{\times}10^{-2}$) was $19.81{\pm}8.32$ before and $25.94{\pm}9.21$ after(p<0.05). 2. The increase in diameter of IAF was approximately one file size for all groups. 3. Ranking of increasing diameter of IAF were GG>CT>OS>PT group. There was a statistically significant difference between before and after flaring(p<0.05). 4 Ranking of the time for flaring were GG>GT>OS>PT group. There was a statistically significant difference between GG group and other groups(p<0.05). 5. In the case without change of IAF diameter, they showed decrease in force after flaring when IAF was pulled out from root canal(p<0.05). This study suggested that early radicular flaring increases the file size that is snug at the apex, and awareness of that difference gives the clinician a better sense of canal size. Early flaring of the canal provides better apical size information and with this awareness, a better decision can be made concerning the appropriate final diameter needed for complete apical shaping.

• 전기화학회지
• /
• 제15권1호
• /
• pp.12-18
• /
• 2012

다양한 응용분야에서 활용될 수 있는 고체고분자연료전지의 경우 현재 상용화에 가장 큰 걸림돌이 되고 있는 것이 고가의 백금 촉매이다. 따라서 특히 최근 들어 산소환원반응에서 백금을 대체하는 물질을 개발하기 위한 연구가 전세계적으로 확산되고 있다. 그러나 촉매 개발 시 경제성 관점 외에 내구성도 고려해야 하는데, 이런 관점에서 백금과 유사한 물성과 활성이 기대되는 백금족 원소들이 한 대안이 될 것이다. 가장 백금과 유사한 물성, 활성을 나타내는 팔라듐과 칼코겐화물 형태의 루테늄이 지금까지 가장 많이 연구가 되었으며 상대적으로 이리듐, 로듐, 오스뮴은 산소환원 촉매로 많은 연구가 되지 않았다. RDE (rotating disk electrode)를 이용한 반쪽전지 실험이나 연료전지 MEA (membrane electrode assembly) 운전을 통하여 백금과 활성을 비교해보면 팔라듐 계열의 비백금 촉매가 가장 백금에 가까운 활성을 나타내고 있음을 알 수 있다. 이 논문에서는 각 백금족 원소들 기반의, 현재까지 문헌상으로 보고된 촉매조성들을 분석하여 비백금 산소환원 촉매 개발에 도움이 되고자 한다.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2008년도 Asian Magnetics Conference
• /
• pp.237.2-237.2
• /
• 2008

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2007년도 춘계학술발표대회
• /
• pp.1323-1326
• /
• 2007

현재 전 세계는 IPv6 조기 도입을 위한 노력을 기울이고 있으며 전략적인 IPv6 인프라 구축 사업을 추진을 하고 있다. 그러나 완전히 IPv6로 전이되기 전까지 IPv4와 IPv6가 공존해야만 한다. 이에 따라 IPv4망에서 IPv6망으로의 안정적인 전이를 위한 상호 운영기술이 필요하다. 이러한 기술을 적용하기 위한 다양한 응용 프로그램의 운영을 위해서 IPv6 기반의 DNS 기술은 그 핵심적인 요소라 할 수 있다. IPv6를 지원하는 Recursive DNS는 기존의 IPv4 기반의 데이터베이스 구조와 플랫폼 및 OS를 IPv6 기반으로 변경해야 하며 IPv4 기반의 DNS 메시지 구조와 이를 처리하는 DNS의 네임 레졸루션 기능이 확장되어야 한다. 따라서 이 논문에서는 IPv6 망 전이를 위하여 변환 프로토콜인 NAT-PT를 이용한 Recursive DNS 구성 방안을 제시한다.

• 한국작물학회지
• /
• 제61권3호
• /
• pp.163-170
• /
• 2016

Heading time is important element for yield and quality in crops. Among day length and temperature which influence on heading, temperature effect has not been investigated well. To investigate temperature effect on heading, heading date and plant growth characters were checked under the low and high temperature conditions in short day length. Analyzing heading date of six Korean varieties under the high and low temperature condition, heading date of varieties were delayed under low temperature. In the low temperature condition, dry weight and area of leaf were reduced. Varieties showing more delay of heading under low temperature also showed more reduction in leaf area. After selecting three varieties showing significant difference in leaf growth and heading date under different temperature conditions, nutrient contents of plant were analyzed. Nitrogen content was reduced in leaf and shoot under the low temperature condition. OsNRT2.3, nitrate transporter, was significantly down regulated in varieties showing more heading delay. Available phosphate content was decreased in leaf, but increased in shoot due to reduction of phosphate mobility. OsPT1, phosphate transporter regulating phosphate uptake, was more down regulated in varieties showing more heading delay. OsPT6, phosphate transporter regulating phosphate transport in plant, was also significantly down regulated in those varieties. With these data, we expected that active nitrogen and available phosphate uptake and transport in plant would increase leaf growth then might reduce heading delay under the low temperature condition.

• Radiation Oncology Journal
• /
• 제36권3호
• /
• pp.182-191
• /
• 2018

Purpose: To investigate the clinical outcome of proton therapy (PT) in patients with chordoma. Materials and Methods: Fifty-eight patients with chordoma treated with PT between June 2007 and December 2015 at the National Cancer Center, Korea, were retrospectively analyzed. The median total dose was 69.6 cobalt gray equivalent (CGE; range, 64.8 to 79.2 CGE). Local progression-free survival (LPFS), distant metastasis-free survival (DMFS), overall survival (OS), and disease-specific survival (DSS) rates were calculated by the Kaplan-Meier method. Results: With the median follow-up of 42.8 months (range, 4 to 174 months), the 5-year LPFS, DMFS, OS, and DSS rates were 87.9%, 86.7%, 88.3%, and 92.9%, respectively. The tumor location was associated with the patterns of failure: the LPFS rates were lower for cervical tumors (57.1%) than for non-cervical tumors (93.1%) (p = 0.02), and the DMFS rates were lower for sacral tumors (53.5%) than for non-sacral tumors (100%) (p = 0.001). The total dose was associated with both the LPFS rate and DMFS rate. The initial tumor size was associated with the DMFS rate, but was not associated with the LPFS rate. Three patients had grade 3 late toxicity with none ≥grade 4. Conclusion: PT is an effective and safe treatment in patients with chordomas. The tumor location was associated with the patterns of failure: local failure was common in cervical tumors, and distant failure was common in sacral tumors. Further refinement of PT, such as the utilization of intensity modulated PT for cervical tumors, is warranted to improve the outcome.

• 대한수의학회지
• /
• 제37권3호
• /
• pp.595-599
• /
• 1997

Male and female Sprague-Dawley rats 8 weeks of age were inoculated per os with 10 Fasciola hepatica metacercariae each. After the infection was verified by fecal examination, they were divided into four groups at 14 weeks post-inoculation; three groups were dosed orally at 10, 20 and 30mg/kg of closantel($Flukiver^{TM}$), a salicylanilide compound and the rest used as untreated control. Efficacy of closantel was monitored weekly by fecal examination of all infected animals starting during the second week post-treatment(PT) and continuing for three weeks. Closantel elicited 96.0, 86.9 and 87.4% efficacy in rats treated with 10mg/kg at the second, third and fourth week PT, respectively. It elicited a 100% efficacy in rats treated with 20 and 30mg/kg.

• 한국식물생명공학회:학술대회논문집
• /
• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
• /
• pp.245-245
• /
• 2005

• International Journal of Computer Science & Network Security
• /
• 제22권12호
• /
• pp.57-62
• /
• 2022

The Sambodana project is a mobile communication security system development project using Hardening Android. The initial idea for this project is that information leakage occurs outside of a communications application with end-to-end cryptographic security. Android hardening prevents unwanted applications and bloatware from being installed, such as unavailable Google Play Store or install restrictions.

• 한국토양비료학회지
• /
• 제43권4호
• /
• pp.438-445
• /
• 2010

단일작물 연작지에서는 일반적으로 토양의 물리 화학적 특성에 많은 문제점을 가지고 있다. 그러므로 본 연구에서는 수박연작지 토양을 선정하여 관행구, 시비관리구, 시비관리 및 패화석 또는 이탄을 처리한 후 토양의 특성변화를 조사하고, 수박의 품질과 관련된 당도 및 과중량의 변화를 조사하였다. 토양 pH는 시비관리-패화석 1.5 t $ha^{-1}$ 처리구에서 약간 증가하는 경향이 있었으나, 모든 다른 처리구에서는 변하지 않거나 약간 감소하였다. 토양유기물함량은 예상되었던 바와 같이 모든 이탄 처리구에서 증가하였고, 패화석 처리구에서는 지속적으로 감소하였다. 토양 중 치환성 양이온 $Ca^{2+}$, $Mg^{2+}$, $K^+$의 농도는 시비관리구 및 시비관리-이탄 처리구에서 감소하였으나, $Ca^{2+}$의 농도만은 시비관리-패화석 처리구에서 약간 증가하였다. 또한 토양 중 수용성 음이온 $NO_3^-$, $Cl^-$, ${SO_4}^{2-}$, ${PO_4}^{3-}$의 농도는 모든 처리구에서 지속적으로 감소하는 경향을 보였다. 그러므로 이러한 양이온과 음이온의 농도 감소로 인하여 관행구를 제외한 모든 처리구에 전기전도도(EC)의 감소로 나타났으며, 이러한 결과는 시비관리, 시비관리-패화석, 시비관리-이탄 처리가 토양조건을 양호한 상태로 변화 시킬 수 있다는 근거를 제공하고 있다. 그러나 이러한 처리는 수박의 품질에는 뚜렷한 영향을 주지 않았다.