탄소섬유 에폭시 복합재료 연삭온도에 의한 연삭특성

한흥삼,이동주 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.6

Although the net-shape molding of composites is generally recommended, molded composites frequently requires cut-ting or grinding due to the dimensional inaccuracy for precision machine elements. During the composite machining oper-ations such as cutting and grinding, the temperature at the grinding area may increase beyond the allowed limit due to the low thermal conductivity of composites, which might degrade the matrix of composite. Therefore, in this work, the tem-perature at the grinding point during surface grinding of carbon fiber epoxy composite was measured. The grinding tem-perature and surface roughness were also measured to investigate the surface grinding characteristics of the composites. The experiments were performed both under dry and wet grinding conditions with respect to cutting speed, feed speed, depth of cut and stacking angle. From the experimental investigation, the optimal conditions for the composite surface grinding were suggested.

GC 연삭숫돌을 이용한 탄소섬유 에폭시 복합재료의 평면 연삭특성에 관한 연구

한흥삼,윤혁중,이동주 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.4

Since carbon fiber epoxy composite materials have excellent properties for structures due to their high specific strength, high specific modulus, high damping and low thermal expansion, the hollow shafts made of carbon fiber epoxy compos-ites have been widely used for power transmission shafts for motor vehicles, spindles of machine tools, motor base, bear-ing mount for tool up and manufacturing. The molded composite machine elements are not usually accurate enough for mechanical machine elements, which require turning, drilling, cutting and grinding. The experiment are surface grinding of the grinding wheel GC60 to the car-bon fiber epoxy composite specimen with respect to stacking angle [0]_nT, [45]_nT, [90]_nT on the CNC grinding machine. In this paper, the surface grinding characteristics of composite plate, which are surveyed experimentally and analytically with respect to the grinding force, surface roughness and wheel loading according to the variable depth of cut, wheel velocity and table feed rate are investigated.

간질환자의 간질 관련 외상

오동호,박운규,이영주,김희태,김승현,김주한,김명호,신동진 대한신경과학회 1998 대한신경과학회지 Vol.16 No.4

척수 경막외 혈관 기형에 의한 재발성 척수병증

오동호,김희태,박운규,이영주,김승현,김주한,김명호,박문향 대한신경과학회 1998 대한신경과학회지 Vol.16 No.5

Metal Oxide Sensor를 이용한 알코올 분석

林香住,姜東求,韓道洙,趙成棟 조선대학교 생산기술연구소 1996 生産技術硏究 Vol.18 No.2

A resistance value of the metal oxide sensor for alcohols was measured by metal oxide senor (FOX2000). T30/1 sensor showed the best response to propanols. The pattern analysis could be measured to ppm and resistance could be processed as various forms. We could find that six sensor responses for propanols were better than those of methanol, when alcohols were displayed at the same time on the radar axis plane with maximum value of △R/Ro by sensors. Alcohols and distilled water were analysed with a principle component and they could be confirmed as being separated clearly.

과학적 관찰과 규칙성 발견 활동에서 나타나는 감성단어 유형과 과학 지식 생성력과의 관계

권용주,신동훈,한혜영,박윤복 한국과학교육학회 2004 한국과학교육학회지 Vol.24 No.6

본 연구의 목적은 첫째, 학생들이 과학적 관찰 및 규칙 발견 활동을 수행할 때 나타나는 과학적 감성 단어의 유형과 빈도, 강도를 분석하고, 둘째, 과학 지식 생성력과 과학적 감성지수(ISE)와의 상관관계를 밝히는 것이다. 이를 위해 연구에서는 먼저 선행 연구를 고찰하여 과학적 감성을 정의하고, 효과적인 지식 생성 활동을 위해 겨울눈과 화석 관찰, 씨앗과 암석 분류의 4개의 과제를 개발 하였다. 연구대상은 교원양성대학교 4학년 학생 161명으로 하였다. 피험자들은 각 과제를 수행하면서 인지적 사고과정과 느낀 과학적 감성을 기록하고 형용사 이모티콘 척도 용지에 자신의 감성 강도를 나타내었다. 연구 결과, 관찰 활동에서는 '흥미-수용-사랑-거부'의 순으로 감성유형이 나타났고, 규칙성 발견 활동에서는 '흥미-거부-수용-기대'의 순으로 감성유형이 나타났다. 각각의 감성 단어 빈도는 감성 강도와 통계적으로 상관관계가 있었다. 과학적 감성 빈도(FSE)와 과학적 감성 강도(SSE)를 곱한 과학적 감성지수(ISE)는 과학적 감성능력을 나타내는 하나의 지표로서 과학 지식 생성력과 높은 정적인 상관관계를 가진다. 개별적인 과학적 감성 지수에서는 '수용-사랑-슬픔-흥미'순으로 과학 지식 생성력과 정적인 상관관계를 나타낸다. The purposes of this study were to analyze types of scientific emotion word and to investigate the relationship between the ISE(Index of Scientific Emotion) and the ability of science-knowledge generation in subjects' scientific observation and rule-discovery. The subjects were asked to perform four scientific tasks. The tasks were developed that are suitable for scientific observation and rule-discovery. In performing tasks, the subjects were asked to describe their generated science-knowledge and scientific emotion through self-report questionnaire, performing each task. The strength of their scientific emotion was also measured using adjective emoticon check lists. In subjects' scientific observing, they showed 33.3% of interest emotion which was the biggest, 15.0% of acceptance emotion, and 11.3% of love emotion, respectively. In scientific rule-discovering, types of emotion were shown as 23.8% of interest, 21.5% of disgust, and 10.8% of acceptance, respectively. In addition, ability of science-knowledge generation was significantly correlated to ISE.

자연언어 처리기법을 이용한 청소용 이동로봇 자동 프로그래밍 시스템

하주한,이기동 嶺南大學校 工業技術硏究所 2004 工業技術硏究所論文集 Vol.32 No.1

There has been an ever increasing interests in mobile robot for human service. In these fields, the end users are not familiar with the generally established teach-and-playback methods. Thus, the user-friendly interface is necessary for such people to teach the desired operation easily. One of the most useful tools for man-machine interface is the natural language interface(NLI). Thus, in this paper, we propose an auto programming system for the service robot - especially in the sweeping mobile robot - using natural language interface. The proposed NLI systems consist of three part: user interface part, natural language processing part, and task manager. After the preprocessing of the input natural language using recursive transmission dialogue grammar, we process the parsing and contextual interpretation of the English-based natural language input sentence according to related database. Finally, this system is simulated and verified under the simple environments.

PMMA와 SAN混合物의 劣化速度에 관한 硏究

薛秀德,韓丞完,金東建,文德柱 동아대학교 공과대학 부설 한국자원개발연구소 1988 硏究報告 Vol.12 No.2

The thermal degradation behavior of the homopolymer poly(methyl methacrylate) (PMMA) and styrene-co-acrylonitril (SAN) as well as their mixture were carried out using the thermogravimetric and infrared spectroscopy method in the stream of various gases. The activation energies evaluated by the reported various kinetics equations except PMMA80%-SAN20% Mixture agreed with each other very well. The thermal degradation of PMMA and SAN mixture were considered to be carried out by the main chain scission.

복합운동형태에 따른 콜레스테롤과 인슐린의 변화

김현,한동성,주진만 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.20 No.1

The purpose of this study is to search into differences between the effect of the jogging training and weight training according to order of jogging training and weight training in the separated two groups and the relation of some physical and biochemical changes on body and finally to find out the optimum exercise program. To achieve this purpose, we constituted two groups - jogging and weight training group(A), weight exercise and jogging group(B). The results of this study are like followings. In the change of blood components before and after training according to exercise order, the statistically meaningful differences are shown in total cholesterol(TC) investigating the change in lipid and lipoprotein concentration with jogging and weight exercise group(A) during a stabilized period. On the other hand, the difference was shown with weight training and jogging group(B) during a stabilized period, immediately after exercise and during recovery time 15 minutes. In addition, there is a meaningful difference in High-Density lipoprotein Cholesterol(HDL-C) with weight training and jogging group(B) during a stabilized period, immediately after exercise and during recovery time 15 minutes. There is also a meaningful difference in Low-Density Lipoprotein Cholesterol(LDL-C) with both groups(A, B) during both stabilized period, immediately after exercise and during recovery time 15 minutes. However, in the difference of change rate between two groups, weight training and jogging group(B) showed higher rate immediately after exercise and during recovery time 15 minutes. There is a meaningful difference in hormone Insulin with both groups (A, B) during a stabilized period, immediately after exercise and during recovery time 15 minutes. However, in the difference of change rate between two groups, weight exercise and jogging group(B) showed higher rate immediately after exercise and during recovery time 15 minutes. Considering the physical and. biochemical changes in blood components(blood cholesterols, insulin) before and after weight training and jogging training group had some positive and statistically meaningful and this training program can be considered as a optimal model of exercise program.

물결합재비 및 단위수량에 따른 고유동콘크리트의 제공학적 특성에 관한 실험적 연구

김규용,한장현,신동주,신홍철,김무한 忠南大學校 産業技術硏究所 1998 산업기술연구논문집 Vol.13 No.1

Recently the study on high flowing concrete which has high workability and non-compacting is being proceeded actively in the university and corporative laboratory. There are some cases that has been applied to the field. This high flowing concrete has higher fluidity and segregation resistance than Plain or flowing concrete. And it is being focused as a remarkable know-how which can make high-quality concrete and reduction effect of labor force. This properties of high flowing concrete are influenced by the relationship of several factors; binder content water binder ratio and unit water content. It is the aim of this study to propose reference data at mix design of high flowing concrete, after comparing and analyzing the fluidity and strength properties of high flowing concrete according to water binder content ratio and unlit water content.