[논문]ZCS를 이용한 간단한 long pulse CO2 레이저 전원

김태균,이임근,김희제 釜山大學校生産技術硏究所 2004 生産技術硏究所論文集 Vol.63 No.-

30Torr 이하 저압 공진기에서 ms order의 long pulse duration을 가진 간단한 펄스 CO2 레이저를 구현하였다. 레이저 시스템의 새로운 전원은 직접 상용전원을 스위칭한다. 이 새로운 전원의 방전 회로에는 정류기, 축전용 커패시터, 또는 전류 제한용 저항이 필요하지 않다. 레이저 출력을 제어하기 위해 펄스 반복률을 최대 60Hz까지 조절했고,SCR의 스위칭각은 30°에서 150°까지 변화시켰다. ZCS circuit과 PIC one-chip microprocessor는 SCR 게이트 신호를 제어하기 위해서 사용되었다. 18 Torr 압력,60Hz 의 펄스 반복률,SCR 스위칭각 90°에서 최대 레이저 출력 35 W를 얻었다. 또한 다른 CO2 레이저와 비교해서 long 펄스를 얻을 수 있었고 이는 대략 3ms(FWHM) 였다.

신피질 세포에서 organic hydroperoxide에 의해 유발된 세포사망

김근태 고신대학교 의과대학 2009 고신대학교 의과대학 학술지 Vol.24 No.1

Background : Previous studies have shown that the hydrogen peroxide induces the cell injury through a lipid peroxidation-independent mechanism in renal epithelial cells. This study was therefore undertaken to examine the roles of lipid peroxidation in t-butylhydroperoxide (tBHP)-induced cell death to renal epithelial cells. Methods : Opossum kidney (OK) cell cultures, a renal tubular epithelial cell line, were used as the renal epithelial cell model. tBHP caused cell death in a dose-dependent manner over the concentration range of 0.05-2 mM. Results : The cell death was effectively prevented by the hydroxyl radical scavenger (dimethylthiourea), iron chelators (deferoxamine and phenanthroline), and antioxidants (DPPD and BHA), but not by the hydrogen peroxide scavenger catalase. tBHP caused a marked increase in lipid peroxidation, which was completely inhibited by DPPD and deferoxamine. tBHP-induced ATP depletion was prevented by deferoxamine and DPPD. Similar protective effects of antioxidants were observed in cell death induced by cumene hydroperoxide, another organic hydroperoxide. However, inorganic hydroperoxide (H2O2)-induced cell death was not altered by antioxidants. tBHP-induced apoptosis was prevented by DPPD and deferoxamine. Conclusions : These results indicate that organic hydroperoxide induces cell death through a lipid peroxidation-dependent mechanism, unlike inorganic hydroperoxide, in renal epithelial cells. 배경:신장 세뇨관 상피세포에서 inorganic hydroperoxide 인 H2O2가 lipid peroxidation-independent mechanism을 통해 세포 상해를 유도한다는 이전 연구 결과가 있었고, 본 연구에서는 신장 세뇨관 상피세포에 organic hydroperoxide인 t-butylhydroperoxide (tBHP)에 의해 유도된 세포사망에 있어 lipid peroxidation이 어떤 역할을 하는지 조사하였다. 방법 : 신피질 세포로는 Opossum Kidney (OK) cell이 이용되었다. tBHP는 0.05-2mM의 범위에서 농도 의존적으로 세포사망을 유도했다. 이러한 세포사망이 hydroxyl기 제거제인 dimethylthiourea, iron chelator인 deferoxamine과 phenanthroline, 항산화제인 DPPD와 BHA, 그리고 H2O2 제거제인 catalase에 의해 어떠한 차이를 나타내는 지를 관찰하였다. 결과 : 세포사망은 dimethylthiourea, deferoxamine과 phenanthroline, DPPD와 BHA에 의해 효과적으로 방지되었으나, catalase에 의해서는 방지되지 않았다. tBHP는 lipid peroxidation을 확연하게 증가시켰으며 이러한 효과는 DPPD와 deferoxamine에 의해 완전히 억제되었다. 또 tBHP에 의해 유도된 ATP 소모도 deferoxamine 과 DPPD에 의해 방지되었다. 항산화제의 이와 같은 방지효과가 다른 organic hydroperoxide인 cumene hydroperoxide에 의해 유도된 세포사망에서도 나타났으나, H2O2에 의해 유도된 세포사망은 영향을 받지 않았다. tBHP가 apoptosis를 유도하였으며, 이는 DPPD와 deferoxamine에 의해 방지되었다. 결론 : 이상의 결과는 신장 세뇨관 상피세포에서 organic hydroperoxide가 inorganic hydroperoxide와 달리 lipid peroxidation-dependent mechanism을 통해 세포사망을 유발함을 의미한다.

강낭콩의 식물체 부위와 생육시기에 따른 무기영양성분 함량과 흡수량에 대한 질소의 사용효과

오태근,이경아,송범헌 忠北大學校 農業科學硏究所 2012 農業科學硏究 Vol.28 No.2

This study was conducted to examine the nitrogen effects on uptake and utilization of major mineral nutrients of the kidney bean (Phaseolus vulgaris L.). The N treatments were five levels, 0, 3, 6, 9, 12 N kg/10a. The kidney bean was cultivated on the upland experimental field in the agricultural ???? research & extensions service of Chungbuk province. The contents and uptake amounts of mineral nutrients were investigated throughout the growth stages of the kidney bean. Higher content of total N in the stem was maintained until 8 days before flowering stage and then decreased gradually. Also, total N content of leaves was increased in the vegetative growth stage, and it was decreased rapidly to 8 days after the flowering stage, and then increased gradually to the initial maturity stage. Total N content of roots was tended to decrease until 8 days after the flowering stage, while that of seed was increased from the flowering stage to the maturity stage. The amount of uptake N of the shoot parts was increased until the flowering stage, maintained similarly from the flowering to 14 days after the flowering stage, and then increased rapidly to the maturity stage, while that of root was increased slowly to the flowering stage and then maintained similarly to the maturity.

만성 통증 질환들의 새로운 분류 및 진단 기준 : 류마티스 관절염, 섬유근육통 및 척추관절염

김근태 고신대학교 의과대학 2011 고신대학교 의과대학 학술지 Vol.26 No.1

Rheumatoid arthritis, fibromyalgia, and spondylarthritis are important diseases causing chronic pain and disability in rheumatologic areas. The classification and diagnostic criterias of them were made on the basis of clinical features, radiologic and laboratory findings and have been used decades ago. According to the development of new knowledge about etiology and pathogenesis of rheumatic diseases, the need for new criteria has been increased. In recent years, new criteria for these diseases have been developed, and they allow the early assignment of diseases and early start of therapy. In this review, the author summarizes recent advances and changes in diagnosis of rheumatoid arthritis, fibromyalgia, and spondylarthritis.

精密測定 計器用 Stainless Steel의 諸性質에 미치는 熱處理의 影響

金善泰,安幸根,韓泰鍾 Natural Science Research Institute JEONJU UNIVERSI 1987 전주대학교 자연과학연구소 학술논문집 Vol.2 No.2

The changes of microstructure and hardness with the various heat treatments on the properties of Fe-13.36% Cr-0.37%C stainless steel for precision measuring gauge have been investigated. Type 420 stainless steel has the self-hardenability, because the nose of isothermal transformation diagram located greatly to the right. The highest hradness in the martensite martrix with undissolved carbide is obtained by oil and air cooling treatment after austenizing at 1000-1050℃, for 1/6-1/3hr. In case of low temperature tempering, internal stress is reduced without dissolution of martensite matrix, and hardness reduced slightly. In case of high temperature tempering, hardness is reduced greatly, because the martensite matrix is dissolved into a ferrite and carbide.

Streptococcus mutans의 치태형성에 대한 Leuconostoc lactis 51의 영향

김태근,양규호,오종석 대한소아치과학회 2000 大韓小兒齒科學會誌 Vol.27 No.4

치아우식증은 치아구조의 국소적, 침윤적, 분자적인 붕괴로 특징지워지는 치아 경조직에 대한 세균성질환이다. 이런 치아우식증의 주 원인균인 S. mutans의 치태형성과 증식에 대한 아동의 구강에서 분리된 L. lactis 51의 작용을 연구하여 다음과 같은 결과를 얻었다. 1.비커 와이어 검사에서 S. mutans와 L. lactis 51의 혼합배양시 S. mutans 단독배양에 비해 치태의 무게가 감소하였다. 2.S. mutans는 S. mutans와 L. lactis 51의 혼합 배양에 비교하여 S. mutans 단독배양시에 생균수가 감소하였다. 3.S. mutans와 L. lactis 51은 M17Y broth에서 단독 및 혼합배양시 배양 12시간 때까지 증가하다가 24시간 때에 감소하였으나, M17YS broth에서는 S. mutans와 L. lactis 51의 혼합배양시 S. mutans의 생균수가 시간이 지남에 따라 감소하였다. 4.L. lactis 51의 배양 상청액은 S. mutans의 치태형성과 증식에 대해 억제 작용을 하지 못하였다. 5.M17YS broth에서의 L. lactis 51 배양 상청액 성분의 thin layer chromatography에서 자당과 과당이 계속 검출되었다. 이상의 결과를 종합하면 구강에서 분리된 L. lactis 51는 S. mutans의 인공치태 형성과 증식을 억제시키는 것으로 사료된다. Dental caries is a bacterial disease of the dental hard tisssus, characterized by a localized, progressive, molecular disintegration of tooth structure. The action of Leuconostoc lactis 51 about plaque formation and replication by Streptococcus mutans was studied as follow. 1.Lower amount of plaque was produced at the mixed culture of S. mutans and L. lactis 51 than S. mutans alone on the wires in the beaker. 2.Fewer cells of S. mutans were replicated at the mixed culture of S. mutans and L. lactis 51 than S. mutans alone. 3.In M17Y broth, viable cells of S. mutans and L. lactis 51 increased for 12 hours, and decreased for 24 hours. In M17YS broth, viable cells of S. mutans showed time-dependent decrease at mixed culture of S. mutans and L. lactis 51. 4.The culture supernatant of L. lactis 51 didn't inhibit the replication of S. mutans and the formation of artificial plaque. 5. Sucrose and fructose were extracted from the culture supernatant of L. lactis 51 in M17YS broth. Thest results suggest that L. lactis 51 isolated from the oral cavity inhibits the replication of S. mutans and the formation of artificial plaque.

웹페이지 체류시간을 활용한 성향분석 시스템의 설계 및 구현

김창근,탁한호,송태섭 진주산업대학교 농업기술연구소 2007 農業技術硏究所報 Vol.20 No.-

If web users visit highly attractive pages during the navigation pattern, they spend more time over viewing and visiting the pages. This can be important information for electric commerce as well as for website owners to analyze what web sufferer’s tastes are. This paper is designated to find out sufferer’s precise taste by estimating how much time sufferers’ spent in certain sites that they have visited.

비용 제약하에서의 소모성 동시조달부품의 최적구매량 결정

吳根泰,金明洙 水原大學校 1998 論文集 Vol.16 No.-

In this paper we consider the CSP requirement determination problem of new equipment(machine) system. For the newly procured equipment systems, mathematical analyses are made for the system which is constructed with the consumable parts to derive the associated CSP requirement determination model in mathematical expression. Based on these on these analyses, a mathematical model is derived for making an optimal CSP requirement determination subject to the constraint of satisfying any given fund limitation. We assume that the failure of a part follows a Poisson process. Firstly, the operational availability concept in CSP is defined and the relation between the general system availability and the operational availability concept in CSP is defined and the relation between the general system availability and the operational availability is established. Secondly, the problem is formulated as the operational availability maximization problem that should satisfy the fund limitation, and then, using the generalized Lagrange multipliers method, the optimal solution procedure is derived.

소아외상 환자에 대한 임상적 연구

한태근,최준 인제대학교 1993 仁濟醫學 Vol.14 No.3

현대사회가 발달하면서 거주의 형태나 생활의 양식이 변하고 있다. 특히 도시의 경우에는 아파트의 밀집, 핵가족화, 여성의 사회참여 등으로 소아의 보호여건이 변하고 있으며 그 외상의 원인 및 상황도 다양한 유형으로 나타나고 있다. 저자는 밀집저주지역에서 소아외상환아를 조사 분석하여 소아외상의 이해와 그에 따른 예방 대책을 세우고자 1989년 9월 1일부터 1970년 8월 31일까지 인제대학교 상계백병원 응급실로 내원한 1452명을 대상으로 장소별, 시간별, 원인별, 보호자의 유무, 외상의 원인된 물체 등으로 분석하여 다음과 같은 결과를 얻었다. 성별비로는 남자가 전체의 67.2%로 더 많았으며 연령별로는 걸음마기(2∼4세)가 47.0%로 가장 많았으며 외상이 가장 많이 발생한 시간은 18시부터 21시 사이였다. 외상의 발생 장소는 54.2%가 집안이었으며 78.7%에서 사고 당시 보호자가 주위에 있었고 더구나 외상에 원인 중 21.5%가 부모의 과실이나 체벌 등이었다. 외상의 원인이된 물체는 특이한 것 없이 행동반경 내의 모든 것이 그 대상이었다. 이상의 결과로 미루어 소아 보호환경의 개선, 안전교육 강화, 놀이기구와 놀이터시설의 안정성 확보등의 대책도 중요하지만 아울러 부모들의 어린이의 안전에 대한 관심이 소아외상 발생을 줄이는 가장 중요한 길이라 하겠다. With the development of contemporary society, forms of residence and ways of life are changing. Particularly in cities, the conditions of child protection are undergoing changes, and the causes and circumstances of pediatric trauma are found in diverse patterns, owing to the trend toward concentrated apartment houses, nuclear familiesm women's social participation, etc. In order to understand and take preventive measures against pediatric trauma through surveying and analyzing externally wounded children in concentrated residential areas. I examined 1452 children who came to the emergency room of Sanggye Paik hospital, Inje University, by place, time, cause, causative object, of their external wounds, and their protector, from Sept. 1, 1989 to Aug. 31, 1990, securing the following result : In sexual distribution ratio, males are 67.2% of the whole. a ratio exceeding that of females. By age, toddler(2-4 years of age) are 47.0%, a percentage higher than that of any other age bracket. By time, most external wounds took place at 18:00-21:00 o'clock. As to place, 54.2% was at home. In cases of 78.9% some protector was nearby at the time of accident. Moreover, 21.5% of the causes of wounds was their parents carelessness or physical punishment by the same. Objects causative of trauma were anything with no distinction in an action radius. In view of the foregoing result, we may come to the conclusion that necessary steps against pediatric trauma are the improvement of protective surroundings for children, the intensification of safety education, the security of safe playthings and playgrounds, etc., but the most important of all is parents' interest in the safety of their children.

운동량변화가 온도변화가 있는 비정상 난류유동장에 미치는 영향

유근종,전원대,김수태 창원대학교 산업기술연구소 2001 産技硏論文集 Vol.15 No.-

In analysis of unsteady turbulent flows with temperature variation, 3 different turbulence models of k-e model, modified k-e model, and Full Reynolds Stress(FRS) model, are applied. 3 Test Cases are selected for verification. These are vertical jet flows with water and sodium, and parallel jet flow with sodium. For overall verification of turbulence models, test cases are analyzed with 2-D and 3-D assumptions. Analysis yields the conclusion that 3-D computation with FRS betters others. However, modified modeling for near wall effect is required to improve its heat transfer characteristic analysis.