3원호 미끄럼 베어링을 적용한 공작기계 주축계의 정적 및 동적 특성 해석시스템 개발

조재완,김석일,이군석,김춘배 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.4

In this study, a static and dynamic characteristics analysis system for machine tool spindle systems with 3 lobe sliding bearings is developed based on Timoshenko theory, finite element method and windows programming techniques. And the characteristic values of 3 lobe sliding bearings such as eccentricity ratio, attitude angle, friction coefficient, stiffness coefficients, damping coefficients and so on, are determined by using the thermal equilibrium condition of spindle sys-tems. Since the developed system has various analysis modules related to static deformation analysis, modal analysis, fre-quency response analysis and so on, it can be utilized to perform systematically the design and evaluation processes of spindle systems with 3 lobe sliding bearings under windows GUI environment.

크랭크샤프트의 기상 계측 시스템 개발

조현용,이원재,조재완,김석일 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

On-machine measurement (OMM) is considered as an effective approach to increase productivity in small batch production. This paper presents a specialized OMM system based on a touch probe, which can be used to measure and estimate the accuracies of crankshaft machined by a 5-axis multitasking machines. Measurement paths were created based on the CAD model of crankshaft and probe radius compensation, and were verified by virtual measurements. An NC program was created by performing the postprocessing of measurement paths, and was transferred to the multitasking machine, directly via RS232C interface. And the accuracies of crankshaft were measured through the touch probe controlled by the NC program. Especially, this specialized OMM system is more effective in case of measuring a large crankshaft because of handling difficulty due to its huge size and heavy weight.

다결정을 이용한 실온에서의 분광 홀버닝 광메모리 구현에 관한 연구

조재헌,백운식,장기완 경희대학교 레이저공학연구소 2001 레이저공학 Vol.12 No.-

The extremely high data densities can be obtained by spectral holeburning, so persistent holeburning has been studied on crystal that doped sm2+ ions at room temperature. To improve performance of persistent spectral holeburning system, we replace a dye laser system by our Littman type external cavity tunable laser diode system.

진동 파ㆍ분쇄기를 이용한 고품질 순환골재 생산기술의 개발에 관한 연구

박승완,조현대,김성수,김성수 대구대학교 산업기술연구소 2009 産業技術硏究 Vol.20 No.1

Skyscrapers and mass housings which built in the time of high economic growth since economic development are renovated as deterioration. And amounts of construction wastes are increasing constantly by demanding new constructions to supply mass housing as well. Hereupon, but construction wastes are being recycled more than 80%, recycle is not enough by the problems on quality of aggregates or user's miss understanding. Due to absent from a core technology, vibrate crusher, or other technology in middle treatment process, people are using inefficient equipments. This caused energy waste, producing efficiency decrease, a falling off in quality and production cost rising etc. Therefore, a purpose on this project is to reduce in a social, environmental and technical charge, and improve a producing technology of high quality cycle aggregates with economical efficiency, productivity and environmental effect from middle treatment process.

타리비드 정(오플록사신 100㎎)에 대한 파비드 정의 생물학적동등성

박완수,조성희,이헌우,임호택,홍성제,서성훈,류재환,이경태 한국약제학회 2005 Journal of Pharmaceutical Investigation Vol.35 No.1

The purpose of the present study was designed to evaluate the bioequivalence of two ofloxacin tablets, Tarivid (Jell Pharm. Co., Ltd.) and Favid (ILHWA Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four normal male volunteers, 23.67±3.12 year in age and 68.50±7.23 kg in body weight, were divided into two groups and a randomized 2x2 cross-over study was employed. After four tablets containing 100 mg of ofloxacin were orally administered, blood was taken at predetermined time intervals and concentrations of ofloxacin in plasma were deter mined using HPLC. Pharmacokinetic parameters such as AUC_(t) and T_(max) were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed AUC_(t), and C_(max) and untransformed T_(max). There were no sequence effects between two formulations in these parameters. The 90% confidence intervals for the log transformed data were acceptance range of log 0.8 to log 1.25 (e.g., log 0.94-log 1.04 and log 0.90-log 1.07 for AUC_(t) and C_(max) respectively). The major parameters. AUC_(t) and C_(max) met the criteria of KDFA for bioequivalence indicating that Favid tablet is bioequivalent to Tarivid tablet.

노인에서 신체질환과 불면증 간의 전향적 연관성

김재민,김성완,양수진,김선영,배경열,조준영,윤탁,신일선,윤진상 大韓神經精神醫學會 2008 신경정신의학 Vol.47 No.5

Objectives : This study aimed to investigate the associations between physical disorders and prevalent/incident insomnia m a community dwelling older population. Methods : 1,204 people aged 65 or over evaluated at baseline. Insomnia was defined as difficulty in initiation or maintenance of sleep on at least three nights per week over the last month. Reported physical disorders covering 11 common and generally chronic health problems were ascertained. Covariates included were age, gender, education, housing, Past occupation, current employment, and depression. Of 879 without insomnia at baseline, 651 (74%) were followed 2 years later, and incident insomnia was evaluated. Results : Prevalent insomnia was significantly associated with 10 of 11 physical disorders. Incident insomnia was associated with 2 physical disorders : eyesight problems and hearing difficulty. Both prevalent and incident insomnia were significantly associated with increased number of physical disorders. Conclusion : Certain physical disorders were comorbid and precipitating factors of insomnia in elders.

Helicobacter pylori의 생육과 각종 유기산의 식품 보존료로서의 효과

송재철,조은경,박현정,신완철,최석영 울산대학교 2002 생활과학논문집 Vol.3 No.2

Helicobacter pylori의 생육과 각종 유기산의 식품보존료로서의 효과를 검토하였다. 우선 보존료로 현재 식품첨가물로 사용되고 있는 소르빈산(sorbic acid), 프로피온산(propionic), 안식향산(benzoic acid) 등의 H. pylori에 대한 항균능력을 검토한 결과 소르빈산, 프로피온산, 안식향산의 H. pylori에 대한 항균효과가 관찰되었으며 안식향산은 소르빈산이나 프로피온산과 비교했을 때는 별로 큰 효과를 나타내지 못하였다. 보존료의 조합에 대한 H. pylori의 생육억제효과는 0.5% 소르빈산과 0.5% 프로피온산을 조합하는 경우 나타났으며 다른 조합군과 비교할 때 큰 차이를 나타내지 못하였다. 유기산과 H. pylori의 생육관계에서는 단독 첨가시에는 항균력이 크게 나타나지 않고 조합하는 경우에만 좋은 항균력을 나타내었다. 유기산, 보존료와 H. pylori 생육관계는 유기산류는 어떤 보존료와 혼합하여도 항균력에 상승효과가 있는 것으로 나타났다. 특히 구연산의 경우 소르빈산과 조합한 경우에는 H. pylori생육이 많이 억제되었으며 그 다음이 구연산+안식향산, 구연산+프로피온산 순으로 균에 대한 항균력이 감소되었다. 또 사과산과 숙실산은 구연산과 비슷한 경향을 나타내었다. The purpose of this study was to examine the effect of various organic acids as food preservatives on the growth of Helicobacter pylori(H.pylor). The antimicrobial effects of sorbic acid, propionic acid and benzoic acid currently used as food preservatives were examined in light of the growth of Helicobacter pylori. Each of them was observed to have positive antimicrobial effect on Helicobacter pylori. However, benzoic acid wasn't higher than sorbic acid and propionic acid in antimicrobial effect. As for the combination of preservatives, antimicrobial activity of H. pylori was shown in the combination of sorbic acid(0.5%) and propionic acid(0.5%). However, its effect was not significantly different in comparison with other combinations. In the relationship of organic acids and H. pylori's growth, organic acid had no effect on antimicrobial activity when it was used alone, whereas antimicrobial effect was shown to be better in case of combination. If intermix of organic acids and preservatives and addition to the medium for suppression of H. pylori growth were achieved, organic acid exhibited synergistic effect on suppression of H. pylori's growth, even in combination of any other preservatives. In particular, in combination of citric acid and sorbic acid, the growth of H. pylori was shown to be remarkable suppression. And the effectiveness on suppression of H. pylori's growth was lowered in order of citric acid + bezoic acid and citric acid + propionic. acid. It was also found that the antimicrobial effects of malic acid and succinic acid were similar to those of citric acid.

Helicobacter pylori의 생육에 영향을 미치는 성분과 식품첨가물에 관한 연구

송재철,정혜진,박현정,조은경,신완철 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.5

본 연구에서는 일반적으로 섭취하고 있는 식품재료나 음식 중에 공통적으로 함유한 성분 또는 가공중에 많이 첨가되는 성분을 선정하여 이들이 Helicobacter pylori 생육에 어떤 영향을 미치는지를 검토하였다. 첫째, 일반식품의 주요 성분인 탄소원, 질소원, 무기질을 대상으로 Helicobacter pylori 생육에 미치는 영향을 검토하였다. 그 결과 식품성분 중 탄소원의 종류에 따라 균일 생육활성은 다르게 나타났다. 우선 단당류가 이당류나 다당류에 비교하여 생육을 촉진하였고 특히 단당류 중 포도당은 가장 균의 생육에 큰 영향을 미치는 것으로 나타났다. 그러나 만노오스는 균의 생육을 오히려 억제시키는 것으로 나타났다. 당알코올류인 솔비톨, 만니톨, 말티톨, 크리시톨 등은 균의 생육에 아무런 영향을 미치지 않은 것으로 나타났다. 질소원과 Helicobacter pylori의 생육과의 관계는 평소 식생활에서 많이 섭취된다고 생각되는 일반 음식에 많이 함유되어 있는 유기형 아미노산 성분고 무기형 질소화합물을 대상으로 균의 생육 정도를 비교하였다. 리신, 메티오닌, 시스테인, 트립토판 등은 균의 생육을 촉진하고 아르기닌, 황산암모늄, 염화암모늄 등은 균의 생육에 도움이 되지 않고 암노니아, 요소등은 균의 생육에 도움이 되지 않고 암모니아, 요소 등은 균의 생육에 조금 영향을 미침을 관찰할 수 있었다. 특히 리신과 메티오닌은 가장 균의 생육에 영향을 미치는 것으로 나타났다. 무기염류의 영향에서는 황산마그네슘, KH-2PO_4, 염화마그네슘 등은 큰 영향을 미치지 못하였고 황산철, 염화제일철, 염화제이철은 생육을 억제하는 것으로 나타났다. 식품첨가물의 Helicobacter pylori의 생육 정도를 검토한 것으로, 그 다음이 질화나트륨, 염화나트륨 순이었으며 토코페롤은 전혀 생육에 영향을 미치지 못하였다. The purpose of this study was to choose principal food components contained in diet foods and food additives used for manufacturing processed foods, and elucidate their in vivo effects on the growth pattern of Helicobacter pylori. To do this, the antibacterial effects of various sources of carbon, nitrogen and mineral as an effect agent on Helicobacter pylori were first assessed based upon bacterial growth degree. Results show that the source of carbon tested had different effects on bacterial growth of Helicobacter pylori. It was revealed that a promotional effect of monosaccharides resulted in enhanced growth of Helicobacter pylori compared with disaccharides and polysaccharides. In particular, glucose was observed to be most effective in growth of Helicobacter pylori among monosaccharides tested, whereas mannose to hinder the growth of Helicobacter pylori. Polyols such as sorbitol, mannitol, maltitol and xylitol was, however, observed to show no promotion or suppression effect on growth of Helicobacter pylori. Apart from these, the sources of amino acid and inorganic nitrogen were chosen and tested to assess the promotion or suppression effect of nitrogen sources on growth of Helicobacter pylori. It was found that amino acid such as lysine showed its promotion effect on the growth of Helicobacter pylori, while arginine, (NH_1)_2SO_4 and NH_4Cl showed no effect on its growth. Ammonia and urea were, however, observed to have a positive effect on the growth of Helicobacter pylori. Among these effect agents, lysine and methionine were revealed to show the most positive effect on growth of Helicobacter pylori. Minerals such as MgSO_4, KH_2PO_4, and MgCl_2 appeared to exert their positive growth effects, whereas CaCl_2, and CaSO_4 had a little effect. In addition FeSO_4, FeCl_2, and FeCl_3 brought suppression on the growth of Helicobacter Pylori. In studies of the growth of Helicobacter pylori by food additives, ascorbic acid showed extreme suppression on its growth. Sodium nitrate and sodium chloride were also found to be of negative effect on the growth of Helicobacter pylori in order of degree, whereas tocopherol had nothing to do with microbial growth.

인간 면역부전 바이러스(HIV) 감염자 사이에서의 1기 및 2기 매독의 유행

장희창,조재현,박완범,이기덕,이창섭,김홍빈,오명돈,최강원 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내 HIV 감염자 사이에서 발생한 매독의 유행을 보고하고, 그 역학적 특성을 규명하고자 하였다. 재료 및 방법 : 1999년 7월부터 2003년 9월까지 서울대학교 병원에서 추적 관찰을 받아온 HIV 감염자를 대상으로 하여 1기 및 2기 매독의 발생을 조사하였다. 발생률을 정확히 구하기 위해 추적 관찰을 받은 모든 HIV 감염자의 인년을 6개월 간격으로 구하였다. 결과 : 51개월 동안, 465명의 HIV 감염자가 서울대학교 병원에서 추적 관찰을 받았다. 이중 38명이 1기 및 2기 매독으로 진단되었다. 1기 및 2기 매독의 발생률은 이기간 동안 100인년 당 4.1명이었다. 1999년 7월부터 2001년 12월 사이에는 발생자가 없었으나, 이후 발생률은 꾸준히 증가하여 2003년 9월에는 100인년 당 18.8명이 되었다. 1기 및 2기 매독의 발생률은 동성애자 및 양성애자에서 이성애자에서보다 4.3배 높았고, HAART로 치료를 받지 않은 환자에서 HAART로 치료를 받고 있던 환자에서 보다 10.9배 높았다. 결론 : 2002년부터 국내 HIV 감염자 사이에서 1기 및 2기 매독이 유행하기 시작하였고, 이러한 유행은 동성애자와 양성애자 및 HAART로 치료를 받고 있지 않던 사람 사이에서 발생하였다. Background : This study was performed to characterize the epidemiologic and clinical features of outbreak of syphilis among HIV sero-positive patients in Korea. Materials and Methods : A retrospective case review of patients diagnosed with primary and secondary syphilis from July 1999 to September 2003 was carried out at Seoul National University Hospital in Korea. To estimate the incidence, person-years (PYs) of all HIV sero-positive patients, who visited the hospital in the same period, were calculated every 6 months. Results : In a 51 month period, 465 HIV-positive patients were followed up at Seoul National University Hospital. 38 cases of primary and secondary syphilis were diagnosed. The incidence of primary and secondary syphilis was 4.1 per 100 PYs during the study period. There was no case from July 1999 to December 2001, and then the incidence rose until September 2003 from 5.5 per 100 PYs in 1999 to 18.8 per 100 PYs in 2003. The rate of primary and secondary syphilis was 4.3 times higher among homosexual and bisexual men than heterosexual men (95% CI 1.87 to 11.17), and 10.9 times higher among patients who did not receive HAART than patients who were receiving HAART (95% CI 5.47 to 21.79). Conclusion : The outbreak of primary and secondary syphilis among HIV-positive patients started in 2002 and has been escalating, especially among homosexual/bisexual men and in patients who did not receive HAART.

내장형 모터와 리니어 모터를 적용한 초고속 수평형 머시닝센터의 열 특성 해석

김석일,조재완 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.5

This paper presents the thermal characteristic analysis of a high-speed horizontal machining center with spindle speed of 50,000rpm and feedrate of 120m/min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motors and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guides. The thermal characteristics such as the temperature distribution, temperature rise, thermal deformation and step response, are estimated based on the finite element model of machining center and the heat generation rates of heat sources related to the machine operation conditions. Especially, the thermal time constant assessed from the step response function is introduced as an index of thermal response characteristics.