산 촉매에 의한 N- (3,4-Dimethoxybenzyl)sulfonamide 유도체의 C-N 결합의 분해

金善嬉,鄭起源,李英行,李寀浩 원광대학교기초자연과학연구소 1992 基礎科學硏究誌 Vol.11 No.2

Cleavage reaction of N-(3,4-dimethoxybenzyl)sulfonamides has been examined. Treatment of these compounds with trifluoroacetic acid afforded sulfonamides which 3,4-dimethoxybenzyl group was removed.

대입 예비생들의 과학교과 충족도 분석

김채옥,김형관,김기수 漢陽大學校 基礎科學硏究所 1988 基礎科學論文集 Vol.7 No.-

1984학년도부터 실시된 새교육과정은 과학교육을 강화하여, 인문계 과정 학생들은 두 과목을 선택하여 이수하던 것을 네 과목 모두 이수하게 하고, 자연계 과정 학생들은 네 과목의 심층부분까지 이수하게 하였다. 그러나 1987학년도 대입학력고사부터는 과목이 조정되어 이수한 네 과목 중 인문계 학생들은 한 과목만을, 자연계 학생들은 두 과목(물리·화학 중 택일은 필수)을 선택하게 되었다. 그 선택방법은 학생들의 선호성향과 충족도에 따라 많은 차이를 보이고 있다. 1985학년도와 1986학년도 대입학력고사 인문계 지원자의 과학과목 선택을 보면 85,86학년도 공히 물리·화학이 0.9%, 화학·생물이 80% 정도를 차지하였다. 이 결과는 암기 과목에 치우친 면을 보였음을 말해주고 있다. 그러므로 본 연구에서는 현재의 고등학교 과학교육이 보편적 교양교육으로 학생들의 요구와 필요를 어느 정도 충족시켜 주는지를 알아 보았다. 그 결과 인문계 0.3%와 자연계 0.9%만이 과학수업을 100% 만족하고 있었고 15.7%와 24.5%가 80% 정도 만족하고 있었다. 한편 대도시에서 농어촌 지역으로 갈수록 과학수업의 충족도가 떨어지고 있음을 보였다. New curriculum reformed in 1984 reinforced the education of science in highschools so that the students of cultural science field were demanded to complete four science subjects instead of two as of old, and the students of natural science field were forced to study four science subjets more deeply than before. Howevere, syllabi have been changed from the 1987 proficency examination of university entrance so as to choose only one out of four science subjects completed for the students of cultural science field, and two(One of them should be physics or chemistry) for the students of natural science field. Thus the choice of subjects shows great difference according to the students preference and sufficiency. In case of the proficiency examination of university entrance in both 1985 and 1986, the preference rate of science subjects for the applicants of cultural science field was 0.9% for physics and chemistry, about 80% for chemistry and biology. This means that the students of this field prefer subjects to memorize its contents easily and blindly. This work, therefore, ideals with whether the education of science in highschool, which is one of the liberal arts courses, satisfies the students needs and necessary. The result shows that only 0.3% of the students in cultural science field and 0.9% of the students in natural science field satisfy perfectly or 100%, but 15.7% and 24.5% of students in each field satisfy nearly or 80%. On the other hand sufficiency of science courses is high in large cities and is decreased as going down to the rural communities.

공기중의 Radon 방사능 측정에 의한 서울 대기의 혼합높이 결정

김의훈,김필수,김채옥,이건상,권기덕 漢陽大學校 環境科學硏究所 1985 環境科學論文集 Vol.6 No.-

서울 대기의 혼합높이를 1984년1월부터 4월 사이에 지표고도에서 측정한 ??으로부터 결정하였다. ?? 농도로부터 상당혼합높이를 계산하기 위하여 한 수식 모델을 개발하였다. 이로부터 계산한 상당혼합높이는 늦은 오후에 최고 및 밤 또는 이른 아침에 최저값을 가지며 수 십 미터에서 1킬로미터 또는 그 이상의 높이를 보이는 일변화를 나타냈다. 평균혼합높이는 겨울이 낮았다. 이와 같은 변화는 대기의 안정도, 일조시간, 기온 등 대기의 인자와 밀접한 관계가 있었다. The mixing heigt of the atmosphere in Seoul was determined from the measurement of ?? concentration in air at ground level for January 1984 to April 1984. In order to calculate the equivalent mixing height from ?? concentration, a mathematical model was developed. The equivalent mixing heights calculated from this model showed diurnal variation with the highest values in the late afternoon and the lowest during night hours or early morning ranging from several tens to one thousand meters or more. The average heights represented lower values in the winter. These variations were closely related to the atmospheric factors, such as atmospheric stability, daytime hour, and temperature, etc.

자궁경부의 상피내암 조직내 In Situ Hybridization에 의한 Human Papillomavirus DNA의 검색 및 Typing

이상숙,김기권,정재홍,김택훈,이태성,진승원,손우익 대한의학협회 1990 대한의학협회지 Vol.33 No.1

多地域 負荷周波數 制御에 依한 動的負荷狀態 推定機構의 效果

裵相賢,丁采榮,李雄基,金蘭 조선대학교 기초과학연구소 1989 自然科學硏究 Vol.12 No.1

This paper presents a method to design pseudo decentralized load frequency control(LFC) based on digital controllers which improves dynamic responses in multi-area power systems by incorporating computational time delay. Assuming that the amplitude of the load fluctuation is small and invariant, behavior of the power system in expressed by a set of linear differential equation, with constant coefficients. First, in order to synthesize a sampled date controller, the system is digitalized at appropriate sampling period by using numerical approximation method. Next, the centralized control gains incorporating time delay are determined based on the optimal theory. In order to damp a constant disturbance, we make use to digital servo system having one controller delay. From the point of view of application to LFC problem, the area control error (ACE) is chosen as output variables of servo system.

繁殖用의 均一系 마우스(ICR-JCL)의 集團飼育에 關한 調査硏究

曺慶鍾,宋南宰,金基弘,鄭英彩 國立保健硏究院 1970 국립보건연구원보 Vol.7 No.-

미세혈관문합때 염산 Ticlopidine의 항혈전 효과

강진성,전종완,한기환,정재홍,김선영 大韓成形外科學會 1987 Archives of Plastic Surgery Vol.14 No.1

Recent progress in microvascular surgery has opened new clinical possibilities in tissue transplantation and replantation by direct anastomoses of vessels less than one mm in external diameter. However, a large obstacle still remains in microsurgery, that is, occlusion of the anastomosis site by thrombosis which is mainly composed of platelets. Many anticoagulants and topical vasodilatic agents such as heparin, aspirin, persantin, coumarin and magnesium sulfate have been used to solve this problem. Heparin inhibits the conversion of prothrombin to thrombin and Factos Ⅴ,Ⅸ,--, Aspirin inhibits collagen-induced platelet aggregation whereas the primary action of persantin is to inhibit ADP-induced platelet aggregation and the release reaction of platelets. Currently, ticlopidine-HCI which is known to inhibit the platelet aggregation to ADP, collagen and epinephrine, is widely in use as an effective anticoagulant for the patients of atherosclerosis, hemodialysis, and subarachoid hemorrhage. Animal study was carried out for the ticlopidine-HCI to investigate the possibility of this agent to be used as a choice of anticoagulant in microvascular surgery. One hundred and twenty rats were divided into 3 groups. Group A was the control group. Aspirin and persantin were given orally in group B. Ticlopidine-HCI was given orally in group C. A femoral artery in one inguinal region and one femoral vein in the other side were severed and then were anastomosed with 10-0 nylon. The wounds were closed with 4-0 black silk. The patency was confirmed grossly and microscopically at 20 minutes, 3 days, and 3 weeks after anastomoses. The patency rates were as follows: 1. At 20 minutes after anstomoses, patency rates of arteries and veins were 100% in all groups. 2. At 3 days after anastomoses, in the control group the patency rates of arteries and veins were 95% and 85% respectively. Group B (aspirin-persantin)were 100% and 90% each. Compared with these, the patency rates of group C (ticlopidine) were better, all of the arteries and veins were patent. 3. At 3 weeks after anastomoses, the patency rates of arteries were 90% and veins were 80% in the control group. Arteries were 95% and veins were 90% in group B, whereas arteries were 100% and veins were 95% in group. C. Therefore, it is concluded that the ticlopidine can be used in microvasular surgery as an anticoagulant of choice.

슬러지 재자원화에 관한 연구

이주성,공성호,서승원,배성렬,김영채,이기철 漢陽大學校 環境工學硏究所 1997 環境科學論文集 Vol.18 No.-

이 연구는 1993년도에 우리나라의 연간 슬러지발생량이 약 3500만m³에 이르고 있으며, 이들 대부분이 매립되고 있다. 그러나 매립부지의 확보가 점점 어려워 지고 있으며 아울러 매립처분비용도 상승하고 있기 때문에 oil화, 퇴비화등으로 재자원화 하는 방법과 소각후의 소각회를 유효이용하는 방법 등이 연구 개발되고 실용화되고 있다. 슬러지의 oil화는 현재 연구단계에 있으나 앞으로 슬러지의 유효이용기술로서, 가장 좋은 방법이 되리라 기대되고 있다. 그러나 소각후의 소각회의 이용방법은 현재 일본등에서는 실용화 되어 건설자재 등으로 다양하게 이용하고 있다. 우리나라에서도 서울시 등을 비롯한 대도시에서는 하수처리장에서 발생하는 슬러지를 소각한 후에 소각회를 건설 자제용으로서 지자체의 공사에는 반드시 사용하도록 하는 제도를 만든다면 유효이용방법으로 충분한 타당성이 있을 것이다. 이때 소각방법으로는 용융소각방법이 보다 효과적일 것이다. With increasing sewage and wastewater sludge, it has become difficult to dispose the sludge by landfilling and ocean dumping. To solve this problem, efforts have been made to delelop sewage and wastewater sludge utilization technologies in many advanced countries. Some technologies have already been developed; conversion of sludge to compost and fuel, producing artificial light-weight aggregate from ashes. This paper describes the technical status of sludge utilization technologies.

Calculation of Site Attenuation for Calculable Dipole Antennas

Ki-Chai Kim,Hyuk-Jun Seo,Tae-Weon Kang,Jae-Yong Kwon,Jeong-Hwan Kim 한국전자파학회JEES 2020 Journal of Electromagnetic Engineering and Science Vol.20 No.2

This paper presents a method for calculating the site attenuation (SA) of an open-area test site (OATS) for a pair of calculable dipole antennas with a 3-dB hybrid balun in the frequency range of 30 MHz to 1 GHz. The SA was directly derived using the concept of power mismatch and dissipative loss from the SA measurement system instead of the concept of substitution loss. Two types of SA formulas using the power loss concept on the treatment of the OATS are presented. The first is the SA formula related to knowing only the value of the SA. The other is the SA formula that analyzed the effects of each part of the SA. Additionally, the constituent losses of the SA measurement system are discussed using the derived SA formula. The analysis of the results showed that the SA could be successfully characterized individually from the loss of the OATS. It also showed that SA is expressed as two kinds of losses: the balanced portmismatch losses of transmit and receive baluns and the half-space dissipative loss. The resultant SA showed good agreement with the results calculated from the S-parameters as well as with the measured results.

Near Fields around Metallic Walls due to a Nearby Dipole Source with Applications to EMC

Kim, Ki-Chai,Lim, Sung Min,Kim, Jong-Woo The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

This paper discusses the near field characteristics of a dipole source located near conducting metallic walls from an electromagnetic compatibility (EMC) point of view. An integral equation for a dipole source near a metallic wall is derived and solved by applying Galerkin's method of moments (MoM). The results show that in the regions outside the dipole source, total electric near fields decrease gradually in magnitude with an increasing field point from the dipole source. But in the regions inside the dipole source, total electric near fields decrease rapidly with a dipole position of $h{\leq}0.3{\lambda}$. For a dipole position of $h{\geq}0.7{\lambda}$, the peaks and nulls of the total near electric field occur periodically in the regions inside the dipole source, and the fluctuation period is almost $0.5{\lambda}$. The worst position for a receptor location is along the z-axis, and a range of a half-magnitude of the maximum near electric field in the principal H-plane is about two times broader than that of the principal E-plane. Experimental measurements are also presented to validate the theory.