Effect of two different calcium hydroxide paste removal techniques on apical leakage : an electrochemical study

Park, Chan-Je,Jeon, Kyung-A,Kwon, Ho-Beom 大韓齒科保存學會 2006 Restorative Dentistry & Endodontics Vol.31 No.3

본 연구의 목적은 근관내 약제로 사용되는 수산화칼슘의 제거방법이 근관충전 후 치근단 미세누출에 미치는 영향을 알아보기 위함이다. 70개의 발거된 단근치를 엔진구동형 ProFile로 근관형성한 후 수용성 수산화칼슘 제제를 1주일간 적용하고 두 군으로 나누어 각기 다른 방법으로 제거하였다. A군은 NaOCI로 근관세정만을 시행하였으며, B군은 근관형성 시 사용된 file보다 한 단계 큰 크기의 ProFile을 사용하여 근관을 재형성한 후 NaOCI로 세척하였다. 근관충전 후 전기화학적 방법으로 24일 동안 치근단 누출을 측정, 비교하였다. 본 연구의 결과 수산화 칼슘 제거를 위한 두가지 방법은 근관충전후 치근단 미세누출에 있어서 차이가 없음을 알 수 있었다. This study evaluated the effect of two different calcium hydroxide (Ca(OH)_(2)) paste removal techniques on the apical leakage of canals obturated with gutta percha cones and sealer after removing a Ca(OH)_(2) dressing using an electrochemical method. Seventy extracted single-rooted teeth were instrumented on with Profile rotary files under NaOCI irrigation. Fifty-eight canals were filled with calcium hydroxide paste, which was then removed using one of the following two techniques. In group A, calcium hydroxide was removed using only NaOCI irrigation, and in group B, the canals were re-prepared with a Profile rotary files-one size larger than the previous instrument and were irrigated with NaOCI. In both groups, the root surfaces were coated twice with nail varnish from CEJ to an area 4㎜ away from the apex after canal obturation. Apical leakage was measured using an electrochemical method for 24 days. All the specimens showed leakddffqage that increased markedly in the first three days. There was no significant difference between the two groups (p > 0.05). The effect of two calcium hydroxide paste removal techniques on the apical leakage was not different during a short period.

초고속 광통신용 Avalanche photodiode의 제작 및 특성에 관한 연구

유지범,박찬용 成均館大學校 科學技術硏究所 1994 論文集 Vol.45 No.2

We review the characteristics of Avalache photodiode(APD) for long haul and high bit- rate optical fiber communication system including basic operating principle, excess noise factor, and bandwidth, and we also summarize recent progress. Separate absorption garding, charge and multiplication APD with charge plate layers instead of guard ring was designed and fabricated using metalorganic chemical vapor deposition and reactive ion etching technique. APD shows 37∼48V of breakdown voltage and very low dark current less than 10 nA at 90% of breakdown voltage. Receiver consisting of APD and Ga As pre - amplifier shows sensitivity of - 33.6dBm in the application of the pseudorandom 2^23-1 non- returen- to- zero(NRZ) patterns at 10^-9 bit error rate(BER).

비장경색이 동반된 쯔쯔가무시병 1예

오종찬,이범주,장재현,원경준,박경희,김동민,박치영,정춘해 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.1

Tsutsugamushi disease is an acute febrile illness caused by Orientie. tsutsugsmushi. It is characterized by fever, myalgia, lymphadenopathy, and rash. And it can be easily diagnosed by characteristic eschar and serologic testing. Nearly all of the patients with tsutsugamushi disease improve with antibiotics such as doxycycline. However, the fatality rate of untreated cases is seven to ten percent. Splenic infarction is not common disease which is caused by occlusion of the main splenic artery or any of its branches. It is mainly caused by emboli that arise from cardiovascular disease, but sometimes by regional thrombosis associated with leukemia, myeloproliferative disorder, sickle cell anemia, pancreatitis, splenic torsion and septicemia. We experienced one case of tsutsugamushi disease with splenic infarction, which was improved after doxycycline treatment finished.

필지 분합을 통해본 서울 북촌 도시조직의 변화 연구

조준범,최찬환 대한건축학회 2003 대한건축학회논문집 Vol.19 No.2

The aim of the study is to define the character of present urban tissues in Bukchon, Seoul through the analysis of the transformation since 1912. The urban tissues of Bukchon are classified as ten types in accordance with the shaped pattern. The urban tissues of Bukchon are composed of the urban tissues which were formed during three period : First pattern have been formed by the process of autonomous growth process based on topographical forms before 1912(such as grid patter, T-shaped pattern, U-shaped pattern, straight cul-de-sac etc). Second pattern have been formed by tosi-hanok which had been constructed through the subdivision of lots by housing construction company from 1912 to 1960s(such as reticulated pattern, branched pattern, linear pattern etc.). First and Second pattern have been transformed by multiple housing, office building etc. after 1960s. Through comparison and observation of the cadastral map of 1912, 1929, 1967, 1989 and 2001, it can be detected that the small size lots which are placed aside of alleys were transformed to medium size lots by amalgamating two or more into one. The urban tissues of 2001 have been transformed to a complete contrast with one of 1912. The transformation of the urban tissues is related to the change of building type from tosi-hanok to non-tosi-hanok

主婦의 쇼핑 라이프 스타일과 小賣店 利用에 관한 實證的 연구

金容纂,金汎鍾 西原大學校 經營科學硏究所 1992 經營硏究 Vol.1 No.1

교수-학습과정의 기호학적 탐구

이찬주,박범석 동국대학교 교육연구원 2005 교육문제연구 Vol.16 No.-

기호학적 입장에서의 의미 전달은 기호에 의한 의미의 교환이라 할 수 있다. 기호가 언어보다 폭넓은 인간 의식의 이해를 반영한다는 점에서, 인위적으로 설정된 상징체계 이외에 자연스러운 상황이나 이미지 자체도 하나의 기호적 의미의 범주로 해석될 수 있다. 교사와 학생의 가르치고 배우는 활동 역시 지식의 일방적인 전수가 아니라, 다양한 기호들이 상호소통함으로써 의미전달과 창출을 끊임없이 경험하는 해석적 활동이 된다. 교육활동 그 자체가 일종의 해석적 활동이기 때문에 이들 사이에 어떤 형태의 의미교환이 이루어지는가를 규명하기 위해서는 교수-학습의 기호적 역동관계를 이해하는 일이 선행되어야 한다. 따라서 교사와 학생 사이의 의미전달과 획득의 측면을 인간의 기호적 인식의 특성을 통해 밝히는 것은, 기존의 텍스트의 성격 이해를 중심으로한 해석적 연구에서 한 걸음 더 나아가 의미화 과정에서 일어나는 교육 주체들의 인식과정을 설명하는 하나의 계기가 될 것이다. The purpose of this study is to investigate the meaning of teaching-learning process in the view of Semiology. In Semiology, education is the enlarging process of meaning between teacher and students in the classroom as a field of signs. It is the hermeneutics activities to student which learn from the teacher and the text. It means students don't take the meanings not just direct way but translating way as their own meaning structures. In the same way, we can say that even teachers don't convey the meaning to students. They translate the meanings for students representing their own understanding structures. It can be said that the teaching and learning process is the relationships of hermeneutic cycle. In Semiotic view points, educational texts is not just the tools of information transmission. We can recognize the educational texts is the dynamic products from the meaningful actions between the two educational agents. These kinds of Semiotic views can give the new visions to clarify the educational communication between teachers and students in the classroom.

CITIS 지원 기술정보관리 시스템의 설계

정석찬,한태창,서범수,조장혁,주경준 한국경영과학회 1998 한국경영과학회 학술대회논문집 Vol.- No.1

CITIS(Contractor Integrated Technical Information Service) is a contractor's developed service to provide electronic access and/or delivery of contractually required information. CITIS satisfies one of the major CALS objectives to furnish a single-entry point for authorized access to contractor-generated Contract Data Requirement List(CDRL) data. A critical requirement for the practical implementation of the CITIS concept is the ability to access multiple existing heterogeneous databases in a fashion transparent to the CITIS user. In this paper, we will propose a prototype system model for CITIS, and discuss the system architecture of proposed CITIS system as a global information management system for distributed and heterogeneous local information systems. Furthermore, we will discuss about the required server module and using-scenario of proposed CITIS system.

초·중·고 학생들의 과학 탐구 능력 추이 분석을 위한 종단적 연구

우종옥,김범기,허명,김찬종,양일호,최관순,김태선 한국교원대학교 과학교육연구소 1999 청람과학교육연구논총 Vol.9 No.1

본 연구에서는 우리 나라 초·중·고등학교 학생들의 과학 탐구 능력에 대한 종단적 추이를 분석하였다. 1997년에는 우종옥 등(1998)이 개발한 검사지를 사용하였으며, 1999년에는 이를 일부만 수정하여 사용하였다. 조사 대상은 성별, 지역별 등을 고려하여 표집하였다. 조사된 자료는 각각 횡단적으로 분석하고, 이를 바탕으로 학생들의 과학 탐구능력이 어떻게 변해 가는지 종단적 추이를 분석하였다. 조사 결과 초등학생들의 과학 탐구 능력은 유의미한차이가 없었으나, 중·고등학생들의 과학 탐구 능력은 유의미하게 향상된 것으로 나타났다. 학교 과학 교육의 질을 과학적으로 관리하기 위해서는 교육과정이 추구하는 교육 목표의 달성이 성공적으로 이루어지고 있는지를 국가수준에서 주기적으로 측정하여 부진의 원인을 진단하고, 개선 방안을 계속 연구하여야 할 것이다. The longitudinal trend of elementary and secondary students' science process skills were investigated to monitor the progress of science learning. Science process skill test, developedin an earlier study on developing a national science process skills assessment system, was revised and administered for the study on March, 1999. Subjects were sampled nation wide according to sex and region. The results of this assessments were compared to those administered on February, 1997. The results showed little difference on science process skills among elementary school students. However, secondary students showed marked increase in science process skills. More systematic and long-term research for assessing science process skills should be planned and performed periodically to provide empirical and foundational data for educational policy making.

한국 행정 모델 및 지식접근체계에 대한 연구

김승윤,전찬흔,이재범 서강대학교 경영학연구원 2003 서강경영논총 Vol.14 No.1

본 연구에서는 분류된 5가지 행정모델을 이용하여 현재 국내 행정모델의 특성을 추출하고, 아울러 행정모델의 전환에 대하여 논의하게 되며, 이를 통하여 한국 행정은 기계적 행정모델에서 네트워크 행정모델로의 이행 시점에 있음을 밝히고자 한다. 네트워크 행정모델 하에서는 지식, 정보, 자료, 멀티미디어 등을 통합한 개념인 컨텐츠가 다양하게 공유되는데, 이 중에서 공유 및 활용의 효과가 가장 큰 것이 지식이다. 네트워크 정부모델 하에서는 지식의 의존도가 그만큼 높아지게 된다. 따라서 지식을 효율적으로 이용하기 위한 방안으로 지식접근체계 개념을 도입하여 행정지식을 사용자 관점에서 분류하고, 이를 통하여 대면공유 전략과 지식재사용 전략의 상호 보완적인 활용이 가능함을 제시한다.

과학 포트폴리오 체제의 적용이 초등학생의 사회심리학적 교실 환경에 미치는 효과

조선형,김찬종,김범기,김철영,김혜정 한국교원대학교 과학교육연구소 2001 청람과학교육연구논총 Vol.11 No.1

The purpose of the research is to investigate the effects of a portfolio system on students' socio-psychological classroom environments in elementary science class. Two schools were selected from a metropolitan area, a city, and one school from a rural area in central Korea. Two fifth-grade classes were sampled from each school selected, and one class is assigned to experimental group and the other to control group, respectively. The total number of participants of the study is 399. Portfolio system was administered to experimental group, and conventional teaching to control group for two and half month. WIHIC, an inventory to measure socio-psychological classroom environment, was administered as a pre-and post-test. Experimental group gained statistically higher scores on WIHIC after administering portfolio system. They showed more positive perceptions on sub-areas of WIHIC such as teacher support, task orientation, and equity. There is interaction between region and group: the effects of the portfolio system is highest in rural area, lowest in metropolitan area, and the city in between. Portfolio system have positive effects on students' socio-psychological classroom environments. Enhanced socio-psychological classroom environments is expected to contribute to positive self-concept, higher science achievements, and self-directed learning.