雪嶽山 신갈나무林의 植物社會學的 硏究

이우철,白元基,金文基 江原大學校 附設 環境硏究所 1994 環境硏究 Vol.11 No.-

A phytosociological study on the Mongolian oak forest was carried out on Mt, Sorak by the Z-M method. The Mongolian oak forest was classified into one oder, two alliances, one association and three communities : Rhododendro-Quercetalia mongolicae Kim 1990 Lindero-Quercion mongolicae Kim 1990 Vaccinium hirtum v. koreanum-Quercus mongolica Community Lespedeza maximowiczii-Quercus mongolica Community Pino koraiensis-Quercion mongolicae Kim 1992 Typical community Lichno-Quercetum mongolicae Kim 1992 Total vascular plant species in investigatied sites consisted of 193 taxa, and their life-farm composition Was H-D_(1)-R_(5)-e type.

컴퓨터 내장형 비파괴검사용 초음파탐상기 개발

김양래,이원흠,김선형,이순흠,최관순,김진구 韓國非破壞檢査學會 1997 한국비파괴검사학회지 Vol.17 No.2

현재 널리 사용되고 있는 비파괴검사중의 하나인 초음파탐상검사(ultrasonic testing)는 교량, 발전소, 석유화학프랜트 및 중공업분야 등에 사용되는 각종 구조물의 사용전ㆍ중검사에 폭넓게 응용되고 있으며, 구조물의 안전관리와 품질관리에 필수적으로 요구되고 있다. 또한, 이들 구조물에 존재하는 결함에 대한 정량적 평가 및 검사 데이타의 해석에 많은 연구가 진행되고 있다. 기존의 초음파탐상검사에 사용되는 휴대용 초음파탐상기의 단점을 보안하기 위해 컴퓨터 내장형 초음파탐상기가 선진국에서 개발되고 있으며 다양한 소프트웨어의 사용에 따른 검사 신뢰도가 향상되고 있다. 본 연구는 컴퓨터 내장형 초음파탐상기를 구성하고, 이를 콘트롤할 수 있는 프로그램, 검사결과의 저장 및 신호 처리 해석이 가능한 소프트웨어를 개발하였다. Ultrasonic testing is one of the most widely used method of nondestructive testing for pre-service inspection(PSI) & in-service inspection(ISI) in structures of bridges, power plants, chemical plants & heavy industrial fields. It is very important to estimate safety, life, quality of structures. Also, a lot of research for quantities evaluation & analysis inspection data is proceeding. But traditional portable ultrasonic flaw detector had been following disadvantages. 1) Analog ultrasonic flaw detector decreased credibility of ultrasonic test, because it is impossible for saving data & digital signal processing. 2) Stand-alone digital ultrasonic flaw detector cannot effectively evaluate received signals because of lack of its storage memory. To overcome this shortcoming, we develop the computer based ultrasonic flaw detector for nondestructive testing. It can store the received signal and effectively evaluate the signal, and then enhance the reliability of the testing results.

결핵성 중이염의 임상적 고찰

박병원,조우령,석상렬,김서규,김명구,권오준,김병헌 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.8

H9c2 심근 세포주에서 외인성 nitric oxide가 허혈에 의한 세포 독성에 미치는 영향

정성구,장현용,김명천,고영관,정주호,배영미,박원서,김대중,유영민,김성수,임성빈 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: Nitric oxide(NO) is known to have protective effects on an ischemic heart and to exert triggering effects on ischemic preconditioning. However, the effects of NO during the ischemic period have not been investigated. To investigate the role of exogenous nitric oxide in a model of ischemic heart cell death, we studied the effects of ischemic preconditioning and ischemia in a normal and an ischemic buffer. Methods: Rat cardiac myoblast cells(H9c2) were cultured in a normal and an ischemic buffered medium. For the ischemic culture of heart cells, the cells were cultured in a dessicator with GasPak for 5 hrs. In ischemic preconditioning, the cells were pretreated with ischemic buffer for 5 min and then perfused with normal medium for 30 min. For the measurement of the cytotoxicity, a MTT(3-4-Sdimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide) assay was performed. A DAPI(4',6-diamidino-2-phenylindole dihydrochloride) staining procedure and a flow cytometry analysis were performed to confirm apoptotic cell death by ischemia. Results: Cell viability, as determined by using a MTT assay, showed that the preconditioned group treated with NO showed more cell death than with the not-preconditioned groups in both normal and ischemic buffers. But, In normal medium and not-preconditioned groups, NO showed protective effect according to the concentrations(100,1000μM) . No treatment with NO produced the different results. In normal medium, the protective effect of ischemic preconditioning was demonstrated, but no protective effect of ischemic preconditioning could be seen in the case of the ischemic buffer. The DAPI staining and flow cytometry analysis of heart cells showed characteristic apoptotic features. Conclusion: NO added in the ischemic phase had deterious effects on heart cells. Ischemic preconditioning was more harmful than ischemia alone. The toxicity of the cells was characteristic apoptosis.

면접조사를 통한 초등학생의 영양교육 실태 및 실천도 조사

오유진,이영미,김정현,안홍석,김정원,박혜련,서정숙,김경원,권오란,박혜경,이은주,성현이 대한지역사회영양학회 2008 대한지역사회영양학회지 Vol.13 No.4

This study investigated the experience and practice of elementary school students on nutrition education. The data were collected from 217 male and female students attending 5-6th grade elementary schools in Seoul and Kyunggi-Do from March to June 2007, interviewing face to face by a nutrition teacher and 3 interns of a nutrition teacher. The results were as follows: 86.5% of the subjects learned about ‘Table etiquette’, ‘Reasons for eating fruits and vegetables’ (78.7%), ‘Food waste and environment’ (72.3%), ‘Healthy snacks’ (55.7%), ‘Food sanitation’ (52.3%), ‘Food culture of foreign countries’ (48.1%). Nutrition education experience was significantly different by gender. A total of 43.5% boys responded that they never learned about ‘basic food preperation’ (p < 0.01). They had learned ‘Nutrients for body’ and ‘Food waste and environment’ in school, ‘Healthy weight loss’, ‘Food culture of foreign countries’, ‘Food circulation’ on television, Most content (‘Table etiquette’, ‘Simple cooking’, ‘Food sanitati n’, ‘Eating behaviors for health’, ‘Reasons for eating fruits and vegetables’, ‘Healthy snacks’) was learned from parents. The practice after nutrition education was higher in ‘Table etiquette’ (2.14), ‘Eating fruits and vegetables’ (2.07) than others compared with education experience. The most reason of non-practice on nutrition information was ‘Troublesome’. In ‘Nutrients for body’, a boy answered ‘Difficult for practice’ 20.0%, a girl answered ‘Difficult to understand’ 32.6%, showing a significant difference between the gender groups (p < 0.001). They remembered the ‘Nutrients for body’ (49.6%), ‘Food sanitation’ (44.5%) because of ‘important content’,‘Basic food preparation’ (40.6%), ‘Food culture of foreign countries’ (36.3%) because of ‘interesting content’, ‘Healthy weight loss’ (52.0%), ‘Eating behavior for health’ (44.5%) and ‘Healthy snacks’ (33.7%) because of ‘need for my health’.

고온수증기 처리에 의한 낙엽송재의 물성변화

김정환,이원희 한국목재공학회 2002 목재공학 Vol.30 No.4

본 연구에서는 낙엽송재(Larix kaemferi Carr.)를 대상으로 100℃부터 130℃까지의 고온영역에서 10℃ 간격으로 처리시간을 10분, 30분, 60분간으로 하여 수증기처리 후 처리재의 물리적 특성 등을 검토하였으며, 오토클레이브를 사용 처리하였다. 휨강도와 압축강도는 처리온도의 증가에 따라 약간씩 감소하는 것으로 나타났다. 그러나 수증기처리한 목재강도와 처리온도 사이에는 명확한 결과가 나타나지 않았다. 120℃에서 130℃의 온도범위에서 세포벽 내의 성분과 조직이 변화하는 것으로 생각되는데, 이것은 응력의 해소에서 기인되는 것으로 생각되었다. 수분흡수성은 고온수증기처리조건에 의한 변화가 없는 것으로 나타났다. 결론적으로 본 실험의 범위에 있어서 목재의 물성은 처리 온도조건보다는 목재밀도의 영향을 많이 받고 있는 것으로 판단되었다. This study deals with physical properties of Larch(Larix kaemferi Carr.) treated by steaming at temperatures above 100℃. Treatment conditions of this experiment were operated at regular intervals of 10℃ at temperature up to 130℃ for 10, 30 and 60 minutes by using the auto-clave. The Bending strength and compressive strength along the grain were slightly decreased with increasing the treating temperatures. There was no significant relations between wood strength and steaming temperatures. At the range from 120℃ to 130℃ of steaming temperature, it was considered that the change of composition and structure in cell wall was changed due to release of stresses. Water absorption characteristics were not affected by steaming temperature. In this experiment limits, it was concluded that physical properties of wood by steaming treatment were affected more largely by wood density than by treating temperature.

고온수중기처리에 의한 낙엽송재의 물성(제2보) : 고온수증기처리에 의한 낙엽송재의 수축율 변화 Effect of high temperature steaming on shrinkages of larch block

김정환,이원희 한국목재공학회 2002 목재공학 Vol.30 No.2

본 연구는 낙엽송(Larix kaemferi Carr.)재를 이용하여 100℃ 부터 180℃ 까지의 고온영역에서 20℃ 간격으로 처리시간을 10분, 30분, 60분, 90분간으로 하여 처리조는 봄베를 사용하였다. 1) 고온수증기처리의 처리시간이 길고, 처리온도가 높을수록 밀도의 감소도 커졌다. 2) 밀도의 감소에도 불구하고 고온수증기처리재의 수축율이 control재와 비교하여 비슷하거나 높게 나타나는 것은 수증기처리에 의하여 세포벽 내부의 구성성분 및 구조변화에 의하여 야기된 것으로 판단된다. 3) 고온수증기처리에 의하여 추정목재의 틀어짐은 감소되었다. This study deals with a physical properties of Larch(Larix kaemferi Carr.) treated at temperatures above 100℃. Treatment conditions of this experiment were operated at regular intervals of 20℃ at temperature up to 180℃ for 10, 30, 60 and 90 minutes by using the bomb, respectively. The results of this study were as follows: 1) The density was decreased with increasing the times and temperatures of steaming. 2) It was considered that the steaming treated specimen's higher shrinkage compared to control was due to change of composition and structure in cell wall. 3) The warpage of half edge grain specimen was decreased by high temperature steaming.

Dam에 依한 洪水 調節 方法의 解析에 관한 硏究

金治弘,安元植 成均館大學校 科學技術硏究所 1986 論文集 Vol.37 No.1

Flood control by reservoir is usually considered to be a principal means of protecting from the flood of a river. The general steps of regulating the flood of a river by dam may be summarized as follows: synthetica analysis of information about the large flood waves in the past, substitution by hypothetical methods of some existing methods of the flood control of a basin, and determination of the most effective way of regulating a reservoir and of its corresponding capacity during the operating stage. The most difficult problem facing the regulation of a reservoir is that while the amount of inflow can be calculated during the stage of planning, it proves to be unpredictable during the stage of actual operation, moreover, the regulation of a reservoir would be impossible without the correct estimation of the amount of inflow. In other words, the difficulty of regulating a reservoir lies in that the amount of flow considered to be the real value during the stage of planning cannot be applicable in the actual operating stage, when the regulation should depend largely on indirect informations and amount of inflow predictable at the moment of operation. The purpose of this paper is to examine the methods of regulating a reservoir through the analysis of flood control by dam.

다중 평행판 축전기형 전송회로를 사용한 질소레이저의 제작과 출력 특성의 기체 온도 의존성

김원호,양준목,추한태 충남대학교 기초과학연구소 1994 忠南科學硏究誌 Vol.21 No.1

We have studied the operational characteristics of a nitrogen laser system which consists of a laser tube of 200 ㎜ in length, multiple parallel plate capacitor type transmission circuitry, pulse type high voltage power source and temperature control system for the nitrogen gas. The optimum operational condition is measured to be 30 ℃ in gas temperature, 70 torr in gas pressure, and E/P of 411 (V/㎝.torr) at 4 ㎜ in spark gap spacing and 20 ㎐ in repetation rate. With increasing the nitrogen gas temperature, the optimum nitrogen gas pressure is found to be increased but the optimum value of E/P is decreased. These results are in accordance with the theory of other studies so far.

Digital moire 형상측정 시스템의 보정에 관한 연구

김도훈,유원재,박낙규,강영준 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

Moire topography method isa well-known non-contacting 3-D measurement method as a fast non-contact test for three-dimension shape measuring method. Recently, it's important to study the automatic three-dimension measurement by moire topography because it is frequently applied to the reverse engineering , the medical, the entertainment fields. Three-dimension measurement using projection of moire topography is very attractive because of its high measuring speed and high sensitivity. In this paper, the classical moire method is computerized-so called digital moire. when a virtual grating pattern is projected on a surface, the captured image by the CCD camera has three-dimension information of the objects. The moire image can be obtained through a simple image processing and a reference grating pattern. and it provides similar results without physical grating pattern. digital projection moire topography turns out to be very effective for the three-dimension measurement of objects. Using different N-bucket algorithm method of digital projection moire topography is tested to measuring object with the 2-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding measurement errors that decreased more by using the four-three step algorithm method instead of the same step in the phase shifting of different pitch.