공작 기계의 신뢰성 평가를 위한 웹 기반 해석 프로그램 개발

강태한,김봉석,이수훈,송준엽,강재훈 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

Web-based analysis programs for reliability assessment of machine tools were developed in this study. First, the reliability data analysis program was developed to search for failure rate using failure data and reliability test data of mechanical part. Second, failure mode analysis was developed through performance tests like circular movement test vibration test for machine tools. This analysis program shows correlation between failure mode and performance test result. Third, tool life was predicted by correlation between flank wear and cutting time, using the extended Taylor tool life equation in turning data and the equivalently converted equation in order to apply ball endmill data to Taylor tool life equation in milling data. All the information related to input and result data can be stored in theses programs.

변압기 보호를 위한 Fuzzy Decision Making 알고리즘

강대훈,이승재,강상희,권태원 明知大學校 産業技術硏究所 1999 産業技術硏究所論文集 Vol.18 No.-

This paper presents a new fuzzy decision making algorithm for power transformer protection based on the Dempster-Shafer's theory of evidence. To distinguish internal faults from other transient states, four input variables are selected. Each time dependent fuzzy rule base is composed of twelve fuzzy if-then rules associated with their basic probability assignments (BPAs) for singleton - or compound-support hypotheses. Dempsters rule of combination is used to process the fuzzy rules and get the final decision. The proposed algorithm also has a capability to identify the inrush, over-excitation and external fault with current transformer (CT) saturation besides the internal fault.

자기진단 CPGFRP에 의한 콘크리트의 파괴 예측 기능의 평가

강태훈,안재철,강병희 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

To maintain serviceability of concrete structure more than proper it is necessary not only predict service life through periodical monitor but also need monitoring system to recognize optimal time and method for repair. Recently, CPGFHP, replacing some GFRP with CF, is developed and used for monitoring concrete fraction. But dramatic resistance change of CPGFHP is showed below 0.5% strain and it is not small strain in terms of monitoring micro crack in concrete. In other word, monitoring with CF is not suitable in low stress but hight stress. In this study, we accessed applicable possibility and reliability of CPGFHP composite as monitoring sense that is proved very sensitive to stress through domestic and oversea previous study. CPGFHP composite plays a role in specimen like steel and increases flexural strength. CPGFHP composite shows resistance increasement in micro crack. In particular, CPGFHP is more sensitive than strangage in low stress. Resistance change ratio curve is very similar to strain curve so sensitivity and reliability is very excellent to monitor concrete fracture.

JIT에서 준비작업(set up)시간의 단축방법

강경식,김태호,나승훈 명지대학교 공학기술연구소 1993 공학기술연구소 논문집 Vol.8 No.-

This study presents the application of a method in just In Time by the singleminute exchange of die(SMED) system and real example. JIT calls for small lots and frequent production runs. So, the setup time are more required in normal operating environment. Set up reduction is a key aspect of Just In Time since it supports reductions in manufacturing lead times and inventories. The SMED system in a technique used to reduce machine set up time. The SMED system is to increase the productivity of machines by reducing their idle time and to reduce machine set up time.

朝鮮后期 書筵과 經筵의 敎育內容 比較 : 肅宗~高宗을 中心으로

姜泰訓 圓光大學校 敎育問題硏究所 1990 敎育硏究 Vol.- No.9

공구 수명의 신뢰성 예측 프로그램 개발

이수훈,김봉석,강태한,송준엽,강재훈,서천석 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

This paper deals with a prediction method of tool life in view of the reliability assessment. In this study, the flank wear was studied among multi-factors deciding the tool wear state. Firstly, tool life was predicted by correlation between flank wear and cutting time, based on the extended Taylor tool life equation of turning data, including parameters of cutting speed, feed rate, and cutting depth. Secondly, each of cutting conditions of endmilling was equivalently converted to apply ball endmill data to the extended Taylor equation. The web-based reliability prediction program for tool life is being developed as one of reliability assessment programs to for the machine tools.

Mastoparan B의 항균 활성 및 용혈 작용에 미치는 소수성도와 양친매성의 영향

이봉헌,김광호,장태식,박남규,박장수,강신원 부산대학교 유전공학연구소 1998 분자생물학 연구보 Vol.14 No.-

Tetradecapeptide인 Mastoparan B(MP B)와 이의〔Ala〕-MP B유도체들을 합성하고 항균 활성 및 용혈 작용을 측정하여 MP B의 활성에 미치는 소수성도(hydrophobicity)와 양친매성(amphiphilicity)의 영향을 비교하였다. 그 결과 MP B와 소수성도가 MP B 보다 큰〔Ala^2〕-,〔Ala^4〕-MP B유도체가 큰 항균 활성을 나타내었으며, 소수성도가 MP B보다 작은〔Ala^6〕-MP B유도체의 활성은 MP B와 비슷하거나 작게 나타나 소수성도가 큰 유도체일수록 항균활성을 크게 나타내었다. 그러나 MP B보다 소수성도가 큰 유도체인〔Ala^9〕-MP B는 Ala에 의한 Trp의 치환때문에 MP B보다 작은 활성을 나타내었다.용혈 활성 측정 결과 MP B보다 소수성도가 큰〔Ala^2〕-,〔Ala^4〕-MP B유도체가 각각100.0%와 69.4%로써 용혈 작용을 크게 나타냈으나, 소수성도가 작은〔Ala^6〕-MP B유도체는 6.1%로써 가장 작은 용혈 작용을 나타내었고 Trp대신 Ala으로 치환한 소수성도가 큰 유도체인〔Ala^9〕-MP B는 MP B보다 작은 26.0%의 용혈 작용을 나타내었다. 그러므로 용혈 작용은 소수성도가 클수록 증가하였으며 양친매성이 활성에 미치는 영향은 적었다. Tetradecapeptide.Mastoparan B(MP B)and its〔Ala^2 〕-,〔Ala^4〕-,〔Ala^6〕-,〔Ala^9〕-MP Bderivatives were synthesized, and then their antibacterical and hemolitic were to examine the effect of hydrophobicity and ampiphilicity on the MP B-induced those activities. MP B and more hydrophobic〔Ala^2 〕-,〔Ala^4〕-MP B showed stronger antibacterical activity and less hydrophobic〔Ala^6〕-MP B than MP B did similar or weaker activity, so more hydrophobic〔Ala〕-MP B derivative had stronger activity. But more hydrophobic〔Ala^9〕-MP B than MP B showed weaker activity because of its Trp subsitution by Ala. On the other hand,〔Ala^2 〕-and〔Ala^4〕-MP B showed 100.0% and 69.4% hemoiytic activity, but〔Ala^6〕-MP B did the weakwst activity(6.1%)and〔Ala^9〕-MP B, weaker activity(26.0%) than MP B.Therefore, more hydrophobic〔Ala〕-MP B derviative had stronger activity and the effect of ampiphilicity on the activity was weak.

Arsenazo I-XAD-2 킬레이트수지를 이용한 U(VI) 이온의 분리 및 농축에 관한 연구

엄태윤,김인환,이창헌,강창희,이시은,이원,임재희 濟州大學校 基礎科學硏究所 1994 基礎科學硏究 Vol.7 No.1

Aresenazo I-XAD-2 킬레이수지를 합성하고 이 수지에 대한 U(VI)이온의 흡착 거동을 조사 검토하였다. 킬레이트수지는 Arsenazo I 킬레이트제와 Amberlite XAD-2의 디아조늄짝지움 반응에 의해서 합성하였으며 원소 분석법과 적외선 분광법으로 확인하였다. U(VI)이온흡착의 최적 조건을 찾기 위해서 pH, U(VI) 이온농도와 진탕 시간에 관해서 조사하였다. U(VI)이온에 대한 킬레이트수지의 전체 흡착능은 pH 4.0∼4.5 범위에서 0.39mmol U(VI)/g resin이었고, pH값이 증가함에 따라 흡착능이 증가하였다. Arsenazo I-XAD-2 킬레이트 수지에 대한 U(VI)이온의 흡착 메카니즘은 U(VI)이온과 H+ 이온 사이의 경쟁반응임을 확인하였다. 컬럼법으로 구한 U(VI) 이온의 돌파점 부피와 전체 흡착능은 각각 600ml, 0.38mmol U(VI)/g resin 이었다. 3M HNO₃와 3m Na₂CO₃의 탈착용액을 사용하여 구한 회수율은 90∼96%였다. 따라서 본 연구에서는 합성한 Arsenaso I-XAD-2 킬레이트수지는 자연수 바닷물 중에 함유된 U(VI)이온의 분리와 농축에 매우 유용함을 알았다. Some sorption behaviors of U(VI) ion on Arsenazo I-XAD-2 chelating resin were investigated. This chelating resin was synthesized by the diazonium coupling of Amberlite XAD-2 resin with Arsenazo I chelating reagent and characterized by elementary analysis method and IR spectrometry. The optimum conditions for the sorption of U(VI) ion were examined with respect to pH, U(VI) ion concentration and shaking time. Total sorption capacity of this chelating resin on U(VI) ion was 0.39 mmol U(VI)/g resin in the pH range of 4.0∼4.5. This chelating resin was showed increased sorption capacity on the increased pH value. It was confirmed that sorption mechanism of U(VI) ion on the Arsenazo I-XAD-2 chelating resin was competition reaction between U(VI) ion and H+ ion. Breakthrough volume and overall capacity of U(VI) ion measured by column were was 600ml and 0.38 mmol U(VI)/g resin, respectively. The desorption of U(VI) ion was showed recovery of 90∼96% using 3M HNO₃and 3M Na₂CO₃as a desorption solution. The separation and concentration of U(VI) ion from natural water and sea water was performed successfully by Arsenazo I-XAD-2 chelating resin.

방향족 폴리에스터 폴리올을 이용한 폴리우레탄 분산체의 합성과 특성에 관한 연구

주훈관,조항규,노시태,강신춘,안재범 한국공업화학회 2004 응용화학 Vol.8 No.1

Aromatic polyurethane dispersions were synthesized with dimethylolpropionic acid (DMPA), isophorone diisocyanate(IPDI), and aromatic polyester polyol, prepared chemical reaction of esterification and polycondensation, The structures of these polyurethanes were characterized by FT0IR, H-NMR, and the properties were measured with DSC, TGA. Increase aromatic polyol contents made of unplasticized polyurethane dispersions. As the aromatic structures in polyurethane dispersions introduced, glass transition temperature(T_(g)) and thermal stability increased. In this polyurethane dispersions increased with DMPA concentrations, particle size decreased and dispersible stability increased and T_(g) increased over 50℃.

규칙적인 신체활동이 청소년의 생활 스트레스에 미치는 영향

길태오,구광수,이강헌 창원대학교 체육과학연구소 2004 경남 체육연구 Vol.9 No.1

본 연구는 규칙적인 신체활동이 청소년의 생활 스트레스에 미치는 영향을 규명하여, 청소년의 생활 스트레스 관리에 규칙적인 신체활동의 긍정적인 효과를 인식시키려는 목적으로 실시하였다. 연구대상은 유층집락 무선표집방법(stratified cluster random sampling method)을 이용하여 운동참여 집단(중학생 120명, 고등학생 93명) 213명과 비참여 집단(중학생 139명, 고등학생 95명) 234명, 총 447명을 표집하였다. 청소년의 생활 스트레스를 측정하기 위한 검사지로는 최해림(1986)의 생활 스트레스 척도를 이용하였고, 생활 스트레스의 영역은 학교생활, 가정생활, 대인관계의 3가지 영역으로 구분하였다. 수집된 자료는 신체활동 참여여부와 학교급별로 평균과 표준편차를 산출한 후 도표화하고, 평균차 검증을 위하여 이원변량분석과 상호작용효과 검증을 실시하여 분석해 본 결과 다음과 같은 결론을 얻었다. 첫째, 규칙적으로 신체활동에 참여하는 학생들은 신체활동을 실시하지 않는 학생들보다 생활 스트레스의 전 영역(학교생활, 가정생활, 대인관계 스트레스)에서 더 긍정적인 반응을 나타내었다. 둘째, 규칙적으로 신체활동에 참여하지 않는 학생들의 경우 가정생활 스트레스는 중학생이 고등학생보다 더 높은 수준이었고, 반면에 대인관계 스트레스는 고등학생이 중학생보다 더 높은 수준이었다.