母乳內 Amylase含量에 關한 硏究

吳東鮮,金舜謙,崔平和 고려대학교 의과대학 1984 고려대 의대 잡지 Vol.21 No.1

It is well documented that human milk contains amylase but not in cow’s milk. Besides the level of amylase activity in saliva and in pancreatic juice is very low at birth, but increases during the first month of life. Present study was carried out to determined the amylase activity in breast milk from various stages of lactation and to compared with that of duodenal juice from infant. The effect of low pH on human milk amylase activity and contribution of human milk amylase activity to total amylase activity in duodenal juice were also studied. Total 201 samples of milk were obtained from 109 mothers during the March to July 1983 and results were as follows. 1) amylase activity was high in colostrums and somewhat lower in milk from day 14 to day 30 after delivery. In this period of lactation, breast milk contained higher amounts of amylase than duodenal juice from infants aged 1 to 6 months. 2) Low amylase activity was found in milk from 4 month or more after delivery. 3) A pH of 5.3 does not inactivate the amylase and there was considerable breast milk amylase activity in duodenal juice after a meal of breast milk. Breast milk amylase could thus contribute to the breast-fed infant’s ability to digest starch.

중학교 남녀학생별 가정교과에 대한 인식 및 학습효과 : 경남지역을 중심으로

신동순,김상희,오화자,정효숙,정혜경 한국 가정과 교육 학회 1997 한국가정과교육학회지 Vol.9 No.1

The aims of this research study is to clear the differences of the learning effects and the cognition of Home Economics by sex in the middle school and to collect the future-oriented educational datas, after implementing the 6th education curriculum. The results of the study are as follows ; 1. Most of students had the cognition that Home Economics is a subject matter of a needful knowledge and skill for the family life, half students a cultural subject matter for the modern life. The former was supported by female students, the latter by male students. 2. Most of students were interested in actual training fields of cooking and hand-sewing, had a strong interest about a field of physical and social-psychological growth. The differences by sex were statistically significant in these fields. 3. Most of students had positive responses in the learning effects of Home Economics. The most useful field was cooking and the worst was the structure and method of sewing machine. 4. The shortage and the dissatisfaction in the learning of Home Economics were lacking of the actual training hours, the old-fashioned teaching methods and the shortage of teaching materials etc.

음향방출을 이용한 저어널 베어링의 조기파손감지(Ⅱ) : Part Ⅱ : Intervention of Foreign Particles in Lubrication 윤활유 이물질 혼입의 영향 및 감시

권오양,윤동진,김경웅,정민화 韓國非破壞檢査學會 1994 한국비파괴검사학회지 Vol.14 No.2

일반적으로 회전기기의 저어널 베어링 부분은 윤활유 공급의 부족이나 윤활층에 이물질이 혼입되면 시스템의 고장이나 가동중단 등의 원인이 되기도 한다. 따라서 베어링 손상에 기인하는 사고와 관련된 안전운전 문제와 유지비용의 절감을 위해 여러가지 파괴 및 비파괴시험법들이 사용되어 왔다. 본 연구에서는 저어널 베어링에서 가장 발생하기 쉬운 윤활층에의 이물질이 혼입에 의해 야기되는 베어링 파손의 조기검출을 위해 음향방출 기술을 적용하였으며, 전보의 연구에 이어 좀더 정량적이고 체계적인 실험을 수행하였다. 실험실용으로 직접 제작한 모의베어링 시스템을 이용하여 여러 형태의 인위적인 이물질 흔입 상태를 만들어 실험하였으며 베어링 손상 및 결함 형태의 해석을 위해 AE rms level, 파형분석, AE 변수 등의 여러 파라메터를 사용하여 분석 고찰하였다. 그 결과 AE rms level의 변화가 이물질 흔입의 영향에 민감함을 보여주었으며 AE변수등 다른 정보들로부터 손상 원일별로 신호형태를 확인할 수 있었다. Journal bearings in the rotating machineries are vulnerable to the contamination or the insufficient supply of lubricating oil, which is likely to be the cause of unexpected shutdown or malfunction of these systems. Various destructive and nondestructive testing methods had been used for the reduction of maintenance cost and the operational safety problems due to the accidents related to bearing damages. In this experimental approach, acoustic emission monitoring in employed to the detection of incipient failure caused by intervention of foreign particles most probable in the journal bearing systems. Experimental schedules for the intervention of foreign particles was composed to be more quantitative and systematic than last study in consideration of minimum oil film thickness and particle size . The experiment was conducted under such designed conditions as inserting alumina particles to the lubrication layer in the simulated journal bearing system. Several parameters such as AE rms level, waveform, AE energy distribution and other AE event parameter are used for analysis and characterization of damage source. The results showed that the history of damage was well correlated with the changes of AE rms level and the types of damage source signal can be verified using other informations such an waveform, distribution of AE parameter etc.

우리나라 M&A에 대한 조세제도에 관한 연구

최영동,오화중 호남대학교 대학원 2004 호남대학교 대학원 논문집 Vol.4 No.-

Lately, encountering the IMF economic crisis, corcorations are reorganizing the system. The tax management becomes the bic issue not only in the enterprise but also in the research. Owing to the change of the national management environments, the reorganization of system is unavoidable, but the enormous burden of taxation makes the rearrangement difficult. Therefore the improvement in the taxation system to remove the obstacle of taxation is necessary. To cope with the change of the management environment, the government revised the tax law in December 1998 and established the several taxation systems for the coalition and division of corporations. Before it, whenever meeting those problems, the government dealt with them sporadically. But this revision is the systematic tax law related with the coalition and division of enterprises. Especially as the division of enterprises is carried out for the first time, Korea will have the advanced taxation system. Generally, the taxation system related with the coalition and division of corporation includes criticism and disputes in explaining and executing the actual tax law. Due to this, in foreign countries, the taxation system connected with the reorganization of companies belongs to the complicated tax area and remains as the long-standing problem. In the case of Korea, the taxation system about the change of the organization of corporation is the first attempt and the cases of execution are insufficient. Therefore many difficulties are expected in enforcing the tax law. The purpose of this study is to classify the several theories about the division of companies and to systemize the theories around the division of corporations.

고속핵에서 GABA가 동맥압에 미치는 영향

이정헌,오기화,안동국,박재식 慶北大學校 醫科大學 1996 慶北醫大誌 Vol.37 No.3

목적 : NTS (nucleus tractus solitarius)는 압감수성 반사 구심성 신경이 처음 시냅스를 형성하는 곳으로 동맥압 조절에 중요한 역할을 한다. NTS에서 어떤 특정 물질이 동맥압 조절에 관여하는지는 정확히 밝혀지지는 않았지만, NTS에 존재하는 많은 물질들이 이들 과정에 관여하고 있다. 그중 하나인 GABA성 약물이 NTS에서 순환계에 미치는 영향을 구명하고자 본 실험을 시행하였으며 아울러 반대편 NTS를 lidocaine으로 억제하였을 경우의 변화를 관찰하여 NTS에서 신경회로 일단을 밝히고자 하였다. 대상 및 방법 : 실험동물은 체중 300-500g 되는 숫컷 Wistar쥐를 사용하였다. 동맥압 측정과 약물 주입을 위하여 대퇴 동정맥에 삽관하였다. 이어서 기관지절개술을 시행하였으며 체온을 36-37℃ 되게 열판을 이용하여 조절하였다. 쥐를 뇌 정위 고정 장치에 두고 머리를 45°숙여 NTS를 노출시킨 다음 약물을 10초간에 걸쳐 80nl주입하였다. 결과 : 인공 뇌척수액을 주입하면 동맥압의 변화가 거의 없었으나 동량의 GABA를 NTS에 주입하면 동맥압이 증가하였다. GABA에 의해 동맥압이 증가된 상태에서 반대측 NTS에 lidocaine을 주입하여 한쪽 기능을 억제시키면 동맥압이 더욱 증가하였다. 또한 lidocaine주입 후 반대쪽의 건전한 NTS에 GABA를 재차 주입하면 동맥압 증가가 적었다. 그리고 GABA를 NTS에 주입 후 정맥으로 nitroprusside를 주입하면 GABA 주입이 없는 대조군에 비해 동맥압 감소가 더 컸으며, lidocaine으로 마취하여 한쪽 NTS의 기능을 차단한 후 반대쪽 건전한 NTS에 GABA를 주입한 경우는 동맥압 감소가 적었다. 동일한 방법으로 lidocaine을 주입한 후 phenylephrine으로 승압을 시키면 동맥압 증가가 적었다. 압감수성 반사는 NTS에 GABA를 주입하거나 또는 반대편 NTS를 lidocaine으로 마취하여 기능을 억제시킨 경우에 둔화되었다. 결론: NTS에서 GABA가 동맥압의 조절 인자로 작용하며, 양쪽 NTS는 상호작용하고 있는 것으로 보인다. The nucleus tractus solitarius (NTS), the site of termination within the brain of baroreceptor afferent fibers, has been shown to be involved in the regulation of arterial pressure (AP). Many neuroactive substances present within the NTS have been shown to be involved in this process, although the manner in which any specific neurotransmitter acts physiologically in the regulation of AP has not been completely elucidated. The present study was intended to clarify the mechanism of action of GABA in the NTS and also to examine the cardiovascular response to inhibition of the contralateral NTS by lidocaine. Male Wistar rats weighing 300-500 g were employed for the experiment. The femoral artery and vein were cannulated to record the arterial pressure (AP) and to inject nitroprusside or phenylephrine, respectively. The tracheotomy was performed and body temperature was kept to 36-37℃. Rats were mounted in a stereotaxic frame with the head flexed downward to an angle of 45°. After the NTS was exposed. GABA or lidocaine was microinjected into the NTS in a volume of 80 nl over 10 seconds through a glass micropipette (outer diameter of the tip 50 ㎛) connected to a 1 ㎕ Hamilton microsyringe. The results obtained are summarized as follows. Microinjection of artificial CSF into the ipsilateral NTS did not alter basal AP. In contrast, microinjection of the same volume of GABA into the NTS produced a significant increase in the AP. The results presented thus far indicated that the volume injected did not affect AP. In animals with elevated AP by GABA injection, injection-of lidocaine into the contralateral NTS resulted in a further increase in AP. After the contralateral NTS was inhibited with lidocaine. injection of GABA into the NTS produced a less increase in AP. After microinjection of GABA into the NTS, the nitroprusside administered i.v. accentuated the increase of AP but not after microinjection of lidocaine into the contralateral NTS. Similar results were obtained with i.v. injection of phenylephrine after pretreatment of lidocaine into the NTS. The baroreflex sensitivity was reduced by microinjection of GABA into the NTS or microinjection of lidocaine into the contralateral NTS. These results suggest that alterations in GABA-mediated neural transmission in the NTS contribute to the regulation of AP and the NTS of both sides have a mutual interaction.

음향 방출을 이용한 저어널 베어링의 조기 파손 감지(Ⅲ) - 저어널 베어링 AE 진단 시스템 개발

조용상,권오양,정민화,윤동진 韓國非破壞檢査學會 1996 한국비파괴검사학회지 Vol.16 No.3

회전 기계의 저어널 베어링 상태를 음향 방출(AE) 기술을 활용하여 감시하기 위한 진단 시스템을 개발하였다. AE 기술은 베어링 시스템에 있어서 비정상 상태를 탐지하기 위하여 이용된다. 모의 저어널 베어링 시스템을 이용한 실험과 실제 발전 설비에 대한 적용 시험의 결과로부터 AE 신호 파라메타 중에서 rms voltage가 가장 유효한 것으로 판명되었으며, 이러한 연구 결과를 토대로 하여 진단 시스템의 알고리즘과 판단 기준들이 설정되었다. 베어링 진단 시스템은 AE 센서 및 전치앰프로 구성된 신호 감지부, AE rms voltage를 측정하기 위한 rms-to-DC 변환 회로부로 구성된 신호 처리부, A/D 변환기를 이용하여 rms voltage 신호를 PC에 연결해 주는 인터페이스부, 베어링 상태 보기와 진단 프로그램을 포함하는 그래픽 디스플레이 및 소프트웨어부의 4부분으로 구성된다. For the condition monitoring of the journal bearing in rotating machinery, a system for their diagnosis by acoustic emission(AE) was developed. AE has been used to detect abnormal conditions in the bearing system. It was found from the field application study as well as the laboratory experiment using a simulated journal bearing system that AE RMS voltage was the most efficient parameter for the purpose of current study. Based on the above results, algorithms and judgement criteria for the diagnosis system was established. The system is composed of four parts as follows: the sensing part including AE sensor and preamplifier, the signal processing part for RMS-to-DC conversion to measure AE rms voltage, the interface part for transferring RMS voltage data into PC using A/D converter, and the software part including the graphic display of bearing condition and the diagnosis program.

전자부품 제조업 근로자들의 시력변화에 대한 연구

이용만,안규동,이성수,함정오,김화성,리갑수,이병국 순천향의학연구소 1996 Journal of Soonchunhyang Medical Science Vol.2 No.2

근접작업이 시력약화의 원인이 될 수 있는가를 알아보기 위하여 전자부품을 제조하는 2개 사업장에서 1991년에서 1993년까지 입사한 근로자들 중에서 근접작업으로 인정되는 마이크로칩을 조립하는 근접작업자 306명을 조사군으로, 대조군은 세탁기 타이머 및 일반 기계기구를 조립하는 작업자 154명, 계 460명을 선정하였다. 이들 대상자는 1991년 입사자는 1993, 1994, 1995년 시력을 조사하였으며, 1992년 입사자는 1993, 1994, 1995년 3년동안 조사를 하였으며, 1993년 입사자는 1994, 1995년 2년간 시력을 조사하였다. 대상자 중에서 입사시 안경을 착용한 근로자는 82명(17.8%)이었다. 따라서 남자 근로자와 안경착용자를 제외한 여성 근로자들 335명만을 추적 조사하여 다음과 같은 결론을 얻었다. 조사군에서 입사시 시력 1.0 이상이었던 근로자의 분포는 취업 1년 후 약 25-35% 정도 감소하였으며, 2년후에는 약 40-60% 정도의 감소를 나타내었고, 3년 후 약 50-65% 정도로 감소하였고 4년후에는 약 65% 이상 감소하였다. 그러나 대조군에서는 1.0 이상의 시력을 보였던 근로자들의 비율이 취업 1년 또는 2년 후 15-30%의 감소를 보이고 있으나 그 이후에는 큰 변동이 없었다. 이들의 시력변화를 근무년수에 따라 알아보기 위하여 조사된 시력을 순위변수로 하여 Kruskall-Wallis 검정을 시행한 결과 조사군, 대조군 모두에서 근속년수에 따른 순위의 합의 평균이 년차적으로 유의하게 감소하였으나, 입사시부터 근속년수에 따른 조사군과 대조군과의 순위합의 평균에 의한 시력차 비교에서 입사시 조사군의 순위합의 평균이 유의하게 높았던 것이 근무기간에 따라 대조군의 평균이 높아지면서 통계적 유의성이 없고 대체적으로 1년 이후부터 변화가 적은 것으로 나타나 근접작업으로 인한 시력약화를 추정할 수 있었다. This study was carried out to investigate that the close distance works were associated with decreased visual acuity. 306 workers were subjects who had been recruited from 1991 to 1993 in two electronic parts manufacturing factories, and 154 workers were controls who had been employed from 1991 to 1993 in launder machine timer and general machine assembly factories. Subjects who had been employed in 1991 and 1992 were follow up from 1993 to 1995, and subjects who had been employed in 1993 were from 1994 to 1995. The male workers as well as glasses wearing workers were excluded. Only 335 female workers were followed up to study the change of visual acuity. The results were as follows; The rate of workers with visual acuity over 1.0 at recruit year in subjects group was decreased about 25-35% after 1 year, 40-60% after 2 years, 50-65% after 3 years, and 65% after 4 years. While, the rate of workers with visual acuity over 1.0 at recruit year in control group was decreased about 15-30% after 1 or 2 years, and there was no more additional visual acuity reduction after then. Kruskall-Wallis test was performed to investigate the change of visual acuity in subject and control group by work duration. The means scores of ranks in both group were significantly decreased by work duration. The mean scores of ranks in subject group at recruit year were significantly higher than those in control group at recruit year, but these differences were disappeared after 1 year work. Therefore, this suggest that close distance workers may be affected their visual acuity.

신규 생리활성물질 개발을 위해 분리한 방선균주의 특성

이모래,김오정,최은화,정동선 서울여자대학교 자연과학연구소 2004 자연과학연구논문집 Vol.16 No.-

Actinomycetes were isolated from soil at Kangdong area in Seoul to screen bioactive metabolites. One of strains having antibacterial activity was selected and characterized. The isolated strain was identified as Streptomyces sp. on the basis of its cultural, morphological and physiological properties. This strain produced antibacterial substances in culture broth after 7days cultivation, and its productivity continued to increase for 14 days. The metabolites exhibited potent antibacterial activities to various bacterial strains including multidrug-resistant strain of Staphylococcus aureus.

마산연안지역의 국지풍 순환 및 대기오염물질 확산에 관한 연구

김유근,이화운,문윤섭,김해동,원경미,정우식,오인보 부산대학교 환경문제연구소 1997 環境硏究報 Vol.15 No.1

To investigate a horizontal windrose and the mixing height in Masan coastal area, a local atmospheric flow and the concentration of air pollutants were analyzed by abserved data from AWS, airsonde and air sampler. The land-sea breeze model and the ISCST2 model of U. S. EPA(Environmental Protection Agency) were used to predict the concentration of air pollutants such as SO2 and TSP. As a result, during spring the principal wind direction in the Masan region is mainly represented by windrose of the WNW and NW, which can be induced by land breeze and the SE and SSW of sea breeze even if weak wind speed. The mixing height during the measurement was marked with the range from 400 m(0900 LST) to 1450 m(1500 LST), and the height of an inverse layer was presented as the range from 30 m(2100 LST) to 150 m(0300 LST). It is very important to cosider the local wind field for the accurate diffusion and movement of air pollutants in coastal urban area. The atmospheric flow was simulated by the two-dimensional local wind model upon considering the orographic characteristics such as land-sea contrast, mountain valley and urban building. The result of air quality simulated by ISCST2 support that the dispersion pattern of the pollutants in that area was followed as local circulation system in coastal urban area.

PECVD로 제작한 수소화된 비정질 탄소(a-C:H) 박막의 광학적에너지 갭과 전기전도도

박혁렬,이석호,오동선,홍선화 木浦大學校基礎科學硏究所 1996 基礎科學硏究誌 Vol.14 No.-

Hydrogenated amorphous carbon(a-C:H) films were deposited onto glass or Si-wafer substrate from CH₄ gas by using PECVD(plasma Enhanced Chemical Vapor Deposition) method. The films were deposited at various substrate temperatures and two different position of the substrate. The optical and electrical properties of the deposited films were characterized by measuring such as UV/VIS transmission spectrum, FTIR absorption spectrum and dark electrical conductivity. We found a decreased in deposition rate and optical energy gap as the substrate temperature was increased. The deposition rate was increased for the films deposited at IS(ion-sheath) region than at BP(bulk-plasma) region, while the optical energy gap was increased for the films deposited at BP than at IS region. We obtained a very hard diamond-like-carbon(DLC) films at IS region and in optimal substrate temperature. The films showed a thermally activated conduction with an activation energy of about 0.24 eV above 400 K, while a variable range hopping conduction below about 400 K.