노화에 미치는 산소 유리라디칼에 관한 연구동향

김정상,나창수,김영곤 한국한의학연구원 1997 한국한의학연구원논문집 Vol.3 No.1

The superoxide anion radical(O₂ ­) poses a threat to macromocules and cell organelles of the living cells. This toxicity damage to all groups of proteins results in loss of enzyme function concerned with metabolism and ion transport, and peroxidation of unsaturated fatty acids and cholesterol results in a change of permeability characteristics of the membrane, and oxidative of nucleic acids results in genomic damage and thereby cause mutation, potential carcinogenesis and somatic damage that produce cellular aging. Superoxide dismutase(SOD) has received substantial attention as a potential therapeutic agent. It has been investigated as a possible agent for the prevention of oncogenesis, the reduction of cytotoxic effect of anticancer drugs, and protection against damage in ischemic tissue. It is suggest that O₂ ­ is concerned with cellular aging, thereafter we need to investigate herb that activated to SOD.

우리나라 株式市場에서의 月中效果와 그 原因에 대한 實證的 硏究

김태혁,이정곤 釜山大學校 商科大學 1995 釜山商大論集 Vol.66 No.-

The purpose of this study is to examine the existence of monthly effects and to discover the causes of monthly effects in the Korean Stock Market. According to the prior empirical studies, the existence of monthly effect varies largely depending on the selection of trading month. The results from this study show the monthly effect, confirmed by the fact that the mean cumulative return of the last half of calendar month exceeds that of the first half of calendar month, significantly exists in the Korean Stock Market opposed to the U.S. Stock Market. This study also found that the monthly effect is affected by corporate disclosure and is heavily influenced by the turn-of-the month effect. The empirical results found are as follows; First, by selecting calendar month as trading month, the monthly effect appears in the Korean Stock Market. Particularly, the fact that cumulative return for the last half exceeds that for the first half totally differs from the prior empirical results including Ariel's study. Second, January effect may affect the monthly effect, but large stocks show stronger evidence of the monthly effect even after excluding the returns realized during January. That is, large stocks have experienced higher month-end returns for the rest of eleven months Third, the weekend effect does not affect the monthly effect, but timely corporate disclosure appears to major causes of the monthly effect. Finally, this study suggests the optimal investment strategy based on utilizing the monthly effect. According to the cumulative returns for nine(six) trading days, the maximum return can be realized by holding stocks from the last five(four) trading days of the particular trading month to the first four(two) trading days of the next trading month. Therefore, it is recognized that the calendar trading effect are heavily influenced by the turn of the month effect.

폴리스타이렌 아이오노머와 액정중합체 블렌드의 기계적 성질

김희석,김준섭,최재곤,박기주,윤용국,진정일 조선대학교 생산기술연구소 1997 生産技術硏究 Vol.19 No.1

The dynamic mechanical properties of thermotropic liquid crystalline polyester (LCP) blends with polystyrene (PS) and Li sulfonated polystyrene (PSSLi) were investigated. It was found that PS forms an immiscible blend with LCP. However, above the matrix T_(g) of the PS, the addition of the LCP increases the modulus of the blend significantly because the LCP acts as filler below its T_(g). In PSSLi/LCP blend system, it was also found that, in the temperature range between two T_(g)s of the ionomer, the LCP acts as filler and thus increases the modulus of the blend. However, the filler effect of the LCP on the modulus decreases rapidly with increasing temperature and disappears above the T_(g) of the LCP. Finally, it was suggested that the PSSLi may be partially miscible with the LCP via ion-dipole interactions between a Li^(+) cation of the PSSLi and a carbonyl group of the LCP.

運動種目別 最適運動遂行 年齡分析

金一坤,김정박,李勇仁 忠南大學校體育科學硏究所 1990 體育科學硏究誌 Vol.8 No.1

The purpose of this paper is searching for the proper age for the most suitable performances in all kinds of sports. We compared the Korean representatives with the other 9 country representatives (U. S. A., U. S. S. R., East Germany, China, Japan, France, Yugoslavia, Hungary, England) who particapated in the Seoul Olympic Games. Finally we got those conclusions. 1. The ages of the Korean representatives in all kinds of sports are generally lower than those of the other 9 country ones. 2. Female representatives a. The average ages of the Korean representatives in all kinds of sports are lower than those of the 9 country one except for basketball. b. The high est average age of the Korean representatives is basketball's 25 and the lowest is gymnastics's 17. c. Equestrian's 36 is the highest in all kinds of sports in each group. 2. Male representatives. a. The average ages of the Korean representatives in all kinds of sports are lower than those of the 9 country ones except for soccer and basketball. b. The high est average age the Korean representatives is shooting's 29 and the lowest is swimming's 23. c. Equestrian's 35 is the highest in all kinds of sports in each group.

Fe 합금의 超常磁性에 관한 연구

金允坤,徐廷鐵 圓光大學校 基礎自然科學硏究所 1984 基礎科學硏究誌 Vol.3 No.1

The superparamagnetic properties of the crystalline alloy Fe_40Ni_38 has been studied by Mo¨ssbauer Spectroscopy and X-ray diffractometer. Mo¨ssbauer spectra of this sample were taken at various temperatures ranging from room temperature to 778˚K. The crystal structrure and particle size were determined by X-ray diffractometer. Mo¨ssbauer spectra shows a relation between temp. and relaxation time.

EVA Nanocomposites 제조 및 특성연구

김영용,박일수,정효선,최재곤,김정규,조병욱 조선대학교 생산기술연구소 2003 生産技術硏究 Vol.25 No.1

Ethylene vinyl acetate random copolymer(EVA)/layered-silicate nanocomposites were prepared by melt or solution blending. The TGA thermograms of EVA/ layered-silicate nanocomposites showed an improved thermal stability as the layered-silicate contents increased. The decomposition temperature of nanocomposite was increased around 10℃ compared with pure EVA at 50% weight loss under N_2 atmosphere And in an air atmosphere, temperature difference in 50% wt loss between the nanocomposlte and the virgin EVA was around 100℃ The moduli in their thermomechanical module of nanocomposite are higher than pure EVA. Interlayered spacings of nanosilicates were slightly increased when prepared by melt blending. On the other hand, they were remarkably increased when prepared by solution blending. It may be explained that EVA moiety of the copolymer showed partial adsorption behavior on the surface layer of the silicate. It also revealed that the adsorption is more effective in the solution blending than in the melt blending.

CORBA 환경에서 프로토타이핑 지원을 위한 재사용 시스템 개발

김행곤,차정은,한덕수 대구효성가톨릭대학교 응용과학연구소 1998 응용과학연구논문집 Vol.6 No.2

In software industry, coexist the software crisis occurring continuously with methodologies and tools for overcoming it. Since 1980's, software reuse and object-orientation have been hot issues in software engineering. Object-oriented methodology can meet user's need concentrating on convenience of development process. By dealing with software product at the component level and by focusing on arbitrarily abstract description of component, software reuse allows user to deal with minute detail. Also, by dealing with software design at the architecture level, it supplies the automation principle of what must be taken in construction process. By hand, in distributed object environment, we can produce the economical software by accessing the data from different and various repository and sharing the data with different user because it support to development the client/server program and integrate existing systems in heterogeneous environment. We implemented the MT-views to utilize the reuse effects as reuse prototyping system or supporting including retrieval, understanding and rebuilding tools based on source code, documentation and etc., using CORBA on distributed object environment.

발효사료 첨가가 돼지의 성장능력 및 도체특성에 미치는 효과

김건중 公州大學校 資源科學硏究所 1996 資源科學硏究論文集 Vol.4 No.-

This experiment was conducted to investigate the effects of dietary supplementation fermented with Appergillus oryzae and Aspergillus niger on body weight gain, feed intake, feed efficiency, nutrient digestiblities and carcass traits of growing- finishing pigs. Sixty crossbred pigs 〔LD(♀) x Y(♂)〕 weighing approximately 20kg, were randomly allotted to 4 treatment and each treatment consisted of 3 replicates and 5 pigs per replicate, after of 120 days feeding trial, pigs were slaughted for carcass quality. The results obtained were as follows: 1.The body weight increased by 4.7kg in the treatment with 20% fermentation feeds added than the control treatment. 2.The feed efficiency was improved by 8% in the treatment with 20% fermentation feeds added than the control treatment. 3.The digestibilities of lipid and total carbohydrate were improved by 4.6%, 3.6% in the treatment with 20% fermentation feeds added than the control treatment, respectively. 4.The lean meat percentage was increased by 2% in the treatment with 20% fermentation feeds added than the control treatment and the backfat thickness was thinned by 0.6cm in the treatment with 20% fermented feeds added than the control treatment.

비행시험을 통한 엔진의 실린더 헤드와 배기가스 온도측정

김진곤,이정모,이정훈,김칠영 한국항공대학교 1994 論文集 Vol.32 No.-

항공기의 운용에서 엔진의 성능 및 운용범위의 설정은 매우 중요한 사랑이다. 엔진의 기본적인 성능은 제작사에서 제시하지만, 항공기에 장착되어 나타나는 엔진의 운용범위는 비행시험을 통해서만 결정딜 수 있다. 따라서, 운용조건의 설정을 위한 일부로서, 엔진의 실린더 헤드 및 배기가스의 온도를 측정하였다. 이들 온도는 고도 및 출력조건이 미리 정해졌을 때, 혼합비 레버의 변화에 따른 온도를 측정하였고, 이러한 오로 부터, 경제출력과 최대 출력이 나타나는 혼합비 조건을 찾았으며, 정상적인 엔진의 운용을 위한 혼합비 조건을 결정하였다. 본 연구에 이용된 항공기는 창공-91이며, 대상엔진은 Textron-Lycoming사의 IO-360-A계열의 200마력 4기통 피스톤 엔진이다. It is very important ot determine the performance and operation envelope of engine for aircraft's flight. The basic performance is provided by manufacturer, but installed engine's operation envelop is only determined by flight test. First, this paper was measured cylinder head temperature(CHT) and exhaust gas temperature(EGT). At pre-determined altitude and power rate, these temperatures were measured by change of mixture ratio and mixture ratio condiotn for economic operation and max. power were found. Normal operation condition for engine was also found with mixture ratio. Chang-91 and Lycoming IO-360-A series four cylinders engine with 200 hp was used for this paper.

금정산 식물상의 변화에 관한 연구

안석곤,남정칠,김석규,조승래 동아대학교 환경문제연구소 2001 硏究報告 Vol.24 No.2

For the purpose of this study is to analyze the flora of plants and forest vegetation of Mt. Keumjung. The results of the study can be described as below. 1. Plants growing at the 8 quadrates of the Mt. Keumjung were 24 families, 36 genuses and 3 species in 1994 and 23 families, 33 genuses and 49 species in 2001. 2. The soil acidity of the 8 areas surveyed here in 2001 was 4.8 to 5.5 in pH, indicating that the soil was gradually being oxidized. The soil hardness was found 15.8 to 28.3 mm, 20.8 in average. 3. Pinus rigida was found highest In dominance, occupying 352% of the total population of arbors, followed by 2.96% for Alnus hirsuta and 2.51 for Styrax japonicn while among the azalea was found highest in dominance, accounting for 44.49% out of the total population of shrubs, followed by 15.14% for Rhododendron yedoense var. poukanese and 3.92 for Rubus idaeus var. concolor. 4. Of the 8 quadrates, sect 8 of the North Gate was highest in the number of extinct trees. 15 kinds. This is probably because of the pressure by climbers' steps. Sect 3 of the West Gate and sect 5 of the South gate had 8 kinds of extinct trees, respectively. The number of newly appeared trees was highest at sect 7 of the North Gate, 8 kinds, followed by sect 5 and sect 6, respectively 5 kinds. 5. At the area of the West Gate(sect 3, sect 4) to which the sabbatical year system(Area : Puk-gu district and a part of Keumjung-gu district) was applied, 21 plant species newly appeared, more than any of the other areas. At the area of the South Gate(sect 5, sect 6). in contrast, 15 plant species disappeared and at the area of the North Gate(sect 7, sect 8). as many as 20 became extinct. The areas surveyed here showed that the extinction of plant species was mainly due to the pressure by climbers' steps rather than to changes in natural environment. To protect the forest and plants of the Mt. Keumjung, thus, it is necessary to increase the period and area of the sabbatical year system and take more effective actions for the management of the forest and plants.