MHD WAVE ENERGY FLUXES GENERATED FROM CONVECTION ZONES OF LATE TYPE STARS

Moon, Yong-Jae,Yun, Hong-Sik The Korean Astronomical Society 1991 Journal of The Korean Astronomical Society Vol.24 No.2

An attempt has been made to examine the characteristics of acoustic and MHD waves generated in stellar convection zones($4000\;K\;{\leq}\;T_{eff}\;{\leq}\;7000\;K$, $3\;{\leq}\;\log\;g\;{\leq}\;4.5$). With the use of wave generation theories formulated for acoustic waves by Stein (1967), for MHD body waves by Musielak and Rosner (1987, 1988) and for MHD tube waves by Musielak et al.(l989a, 1989b), the energy fluxes are calculated and their dependence on effective temperature, surface gravity and megnetic field strength are analyzed by optimization techniques. In computing magneto-convection models, the effect of magnetic fields on the efficiency of convection has been taking into account by extrapolating it from Yun's sunspot models(1968; 1970). Our study shows that acoustic wave fluxes are dominant in F and G stars, while the MHD waves dominant in K and M stars, and that the MHD wave fluxes vary as $T_{eff}^4{\sim}T_{eff}^7$ in contrast to the acoustic fluxes, as $T_{eff}^{10}$. The gravity dependence, on the other hand, is found to be relatively weak; the acoustic wave fluxes ${\varpropto}\;g^{-0.5}$, the longitudinal tube wave fluxes ${\varpropto}\;g^{0.3}$ and the transverse tube wave fluxes ${\varpropto}\;g^{0.3}$. In the case of the MHD body waves their gravity dependence is found to be nearly negligible. Finally we assesed the computed energy fluxes by comparing them with the observed fluxes $F_{ob}$ of CIV(${\lambda}1549$) lines and soft X-rays for selected main sequence stars. When we scaled the corrected wave fluxes down to $F_{ob}$, it is found that these slopes are almost in line with each other.

자동차 박판구조 접합 강도에 미치는 오일의 영향

문윤배,유재용 대구미래대학 2001 論文集 Vol.19 No.1

The improvements of the thin plate joint method are required because of the application of thin plate structures are diversified. The purpose of the investigation is to evaluate the applicability of the structural adhesive on the thin plate structures. This study is performed to evaluate how the jointing effects with oil are improved, compare with that of spot welding specimens after the tensile shear test under the various conditions of the specimen, which had the single lap joints by bonding and weldbonding for the structural jointing techniques.

동북아 고대 해상무역제도에 관한 고찰 : 장보고의 통상네트워크와 관련하여

윤광운,박명섭,김재승,손성문 국제무역학회 2002 국제무역연구 Vol.8 No.1

본 연구는 통상사적 측면과 무역상무론적 관점에서 9세기 동북아 해상교역환경과 장보고의 해상무역의 실체를 규명함으로써 오늘날 동북아지역간의 통상협력을 통한 발전방향을 모색하는데 그 목적이 있다. 이를 위해서 본 연구에서는 9세기 통일신라, 중국의 당나라 및 일본을 중심으로 한 동북아지역의 해상교역제도의 일반환경과 발전요소를 분석하고, 장보고 해상무역의 특성 및 교역관행 그리고 물적·인적 네트워크를 통한 동북아 통상네트워크 기반을 분석하고 있다. 특히 동북아지역 통상네트워크의 구축을 기반으로 하고 있는 장보고 해상교역의 특성으로 우선 지리적으로는 고대 동북아지역을 중심으로 한 통일신라의 청해진과 중국 당대의 산동성 법화원 그리고 일본의 하까다지점을 연결하는 해상교역네트워크를 구축한 점이고 둘째, 해상교역관행으로 주로 중계무역형태와 선불제도관행, 통상정책적 제반활동을 수행한 점과 셋째, 해상교역의 주요 수단으로 신라의 항해술과 당대의 발달된 조선술을 기초로 하고 있음을 알 수 있다. 이러한 점은 해상교역을 통하여 새로운 시장과 제품, 신사고라는 국제교역의 동기를 바탕으로 하여, 오늘날에도 여전히 국제무역의 주요 요인으로서 향후 동북아지역의 새로운 통상환경의 기반을 더욱 촉진할 필요가 있다. The purpose of this paper is to survey the ancient marine trade in Northeast Asian Area and present the directions for developing through the economical cooperations among Korea, China and Japan in Northeast Asian district. In order to achieve of above purposes, this paper investigated the environments of marine trade and the practices of Changbogo's marine trade focus on Silla, Tang in China and Japan in the 9th century. The features of Changbogo's marine trade are as follows: First, geographically, Changbogo constructed marine trade network linking in Silla, Tang, Japan, in the center of ancient Northeast Asian areas Second, Types of marine trade is largely today's intermediary trade Third, His marine trade depended on the technical improvement of navigation and shipbuilding. These things are also central factors of today's international trade and they are necessary to open up a new market through the marine trade.

PC U형의 단면을 사용한 포스트텐션된 넓은 보-기둥 내부접합부의 비탄성 거동

최윤철,임재형,문정호,이리형,권기혁 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.1

Post-tensioned precast concrete system(PPS) consists of U-shaped precast wide beams and concrete columns. The continuity of beam-column joint is provided with the topping concrete on the PC shell beam and post-tensioning. The purpose of this paper is to evaluate the response of PPS interior beam-column joint subjected to cyclic lateral loading. To this end, the experimental investigation was performed with three half-scale specimens of interior connection. The design parameter is the ratio of beam width to column width. Test results showed that cracks were distributed well and plastic hinges spread toward midspan without any significant degradation of strength and ductility. And the specimens sufficiently resisted up to the limiting drift ratio of 0.035 given by ACI of acceptance criteria for concrete special moment frames.

사람 혈청 Vitronectin의 정제 및 항 Vitronectin 다클론 항체의 생산

장윤혜,김백남,이성순,문경,김승후,이재담 大韓免疫學會 1996 大韓免疫學會誌 Vol.18 No.2

Background: Vitronectin is one of major cell- adhesive glycoprotein in mammalian serum and plasma ; the other is fibronectin. It is a mixture of 65 and 75kDa protein in plasma which promotes spreading of a variety of cultured cells ,inhibits the cytotoxicity of membrane attacks complex C5b-7 and modulates thrombin-antithrombin III activity. Human plasma and serum contain 10-40mg of vitronectin per 100ml,but only a few mg or less of vitronectin can be isolated with a 0.5-20% recovery efficiency through very long processes or with expensive,commercially available monoclonal antibody. In this study, we purified the vitronectin from human plasma and produced anti-vitronectin polyclonal antibody using purified vitronectin. Methods: Vitronectin was purified from the human plasma by heparin-sepharose column and its efficacy was measured by cell spreading assay. Anti-vitronectin polyclonal antibody produced and confirmed by ELISA and immunoblotting. Results: This procedures produced about 0.8mg vitronectin from 100ml human plasma within 2 days. 1) Purified vitronectin promoted spreading of HepG2 hepatoma cells on substrates with a half maximal activity at 0.lug/ml. 2) In SDS-PAGE analysis of purified protein, 2 bands were found and their molecular weights were 75kDa and 65kDa,respectively. 3) The immunoblotting assay showed that the bands of molecular were same site as SDSPAGE analysis. Conclusion: Simple,rapid purified vitronectin by heparin-sepharose column and anti-vitronectin antibody may facilitate the elucidation of vitronectin function and action mechanism in human body.

Uzbekistan 공화국의 농업현황

곽재균,조은기,김행훈,윤문섭,석순종,김창영 한국국제농업개발학회 2004 韓國國際農業開發學會誌 Vol.16 No.2

1. Uzbekistan은 전통적인 농업국가로서 농업이 경제의 축이며 농촌인구가 60%,농업부문 종사자가 전 산업에서 차지하는 비율이 44%이고 농업생산이 GNP에서 차지하는 비중이 33%로서 비교적 높은 편이다. 2. 이 나라의 농업은 강우량이 적고 건조한 기후조건 때문에 주로 관개에 의존하고 있으며 안공수로와 저수지의 건설로 관개가능 면적은 430만㏊ 이고 충분한 수량만 확보된다면 700만㏊ 까지 경작이 가능하다. 농업생산은 목화, 밀, 벼, 포도, 채소, 멜론재배가 주종을 이루고 있으며 특히 일조시수가 3,000시간으로 매우 길고 일사량도 많아 목화, 고품질의 포도와 멜론 생산이 유명하다. 3. 축산업도 농업에서 중요한 부문으로 주로 유목에 의존하고 있으며 염소, 고기소, 젖소, 면양이 주된 가축이고 양잠업도 중요한 위치를 차지하고 있다. 4. Uzbekistan은 맥류, 목화, 포도, 사과, 양파 등의 원산지 일 뿐만 아니라 박과 작물의 2차원산지로서 유전적 다양성이 풍부하고 특히 멜론은 많은 재래종 품종들이 분화되어 재배되고 있다. 5. Uzbekistan는 1995년 한·우즈벡 농업기술협력 가능성 조사 이후 1996년부터 양국간 유전자원 공동연구가 활발히 추진되고 있다 금후 인근 중앙아시아 각국과의 유전자원 또는 농업관련 공동연구를 수행함에 있어 우즈베키스탄을 전진기지로 활용하는 방안이 적극 모색되어야 할 것으로 사료된다. The Republic of Uzbekistan is located in the central part of the middle Asia. The area of the Republic makes up 447.4 thousands ㎢ and about 60% of the country is semi-desert or desert with only 4.5 million hectares of the area cropped. The average temperature in July on the plains' territory varies from 26℃ in the North to 30℃ in the South, and the average temperature in January falls to as low as 0℃ in the South and to -8℃ in the North. Precipitation primarily occurs during the winter-spring period. Annual precipitation amounts to 80-200 ㎜ on the plains, 300-400 ㎜ in the foothills area and 600-800 ㎜ on the eastern and south-eastern slopes of the mountain ridges. Natural pastures occupy 50.1% of the total area of Uzbekistan, and 9.7%(4.3 Min. ha) of irrigated lands. Irrigated land is mainly cultivated for cotton, spiked cereals, rice and potato. Cotton plants occupy 36.5% of the cultivated areas and grain crops 39.5%. Given the abundance of solar radiation and heat, the major factor limiting the use of agroclimatic and land resources is a deficit of water. Agriculture in Uzbekistan was and still is the largest sector in Uzbekistan's economy. Agriculture and it's related industries account for approximately 33% of GDP, and 55% of the hard currency revenues of the country is related to Agriculture. Approximately 60% of the population resides in rural areas, and 44% of the work force is engaged in agricultural production. Uzbekistan is the world's fifth largest cotton producer and the second largest exporter. Cotton has been center to the economy because it accounts for about 50% of the country's export earnings. At the same time, however, cotton production has depended on vast amounts of irrigation, and this has had a possibly significant irreversible negative impact on the Aral Sea. The development strategy in the agricultural sector in the country is targeted at ensuring food and environmental security, while increasing the efficiency and export-potential of domestic production. According to the macroeconomic forecast, the agrarian sector will maintain its leading role in the economy (at 25% of GDP). To meet the strategic development goals by 2010, annual growth in agricultural output must be at least 5-6%.

등방성-등방성 이종재료에 대한 균열 선단에서의 코스틱스 상에 관한 해석

유재용,문윤배 대구미래대학 2001 論文集 Vol.19 No.1

For the stress analysis in bi-materials, there have been used many theoretical and experimental methods. The experimental methods such as Morie, Photoelasticity, holography and caustics are primarily used by many researchers. In this paper, as the first step to develop the experimental method of caustics in bi-materials, the initial and caustic curve equations are established by introducing the existing stress component equations to the equation of the formation of Caustics and made the program for the generation of caustics in computer.

핵연료에서 핵분열 생성물의 방출 기구에 관한 연구

양재춘,이호연,정문규 충남대학교 기초과학연구소 1986 연구논문집 Vol.6 No.-

중성자와 우라늄의 핵 반응에 의해 생성된 핵분열 생성물의 물리적 특성을 이용하여 원자로 내의 핵연료 상태를 해석하는 새로운 모델을 도입하였다. 고체 핵연료 내에서 핵분열 생성물의 생성과 이것의 원자로 냉각재까지 방출되는 과정을 계산하는 방정식을 세웠다. 이 방정식으로 핵분열 생성물의 source term을 계산하고, 이것이 고체 핵연료 내에서 방출되어 gap과 핵연료 피복재를 통하여 원자로 냉각재까지 방출하는 양을 계산하였으며, 원자로 1차 냉각재에서의 tramp uranium양을 계산하였다. 이 방정식을 computer로 계산하기 위하여 전산화 하였다. 실험 자료로는 가압 수형 원자로 (Pressurized Water Reactor)인 고리 원자력 발전소 1호기의 제 3주기 동안에 핵연료의 상태를 감시하기 위해 1차 냉각재를 분석해서 얻은 핵분열 생성물의 방사능 강도를 이용하였다. 이 실험 자료와 위 방정식에서 계산한 방사능 강도를 비교하여 결함 핵연료 수와 tramp uranium 양을 구하였다. 이렇게 구한 결과와 고리 1호기의 제 3주기 말에 핵연료 재장진을 위해 수행한 sipping test 결과를 비교해 보았다. 그 결과 본 연구에서 도입한 모델이 잘 맞는 것을 알 수 있었다. We propose the new model which analyzes the nuclear fuel state of the reactor from the physical characteristics of nuclear fission products which are produced by reactions between neutron and uranium 235. The main feature of this model is to calculate the generation of fission products inside the solid nuclear fuel and the release mechanism of fission products into the reactor coolant. Using the computer we solved the equation of the model and put the experimental activity data of the fission products to determine the number of failed fuel rods and amount of tramp uranium. These data had been taken from the primary coolant of the Kori Nuclear Generating Station, Unit 1. This result of our calculation is in a fairly good agreement with the result of the sipping test during the refueling period for cycle 3 of the Kori Nuclear Generating Station, Unit 1. As a result of this research we conclude that our model for the release mechanism of unclear fission products in reactor fuel is well describing the actual processes.

다발성 골수종으로 이행한 단일형질세포종 1예

정재용,모성환,기장도,문철호,김창욱,전용준,박유환,정춘해,오윤경 조선의대 1995 The Medical Journal of Chosun University Vol.20 No.2

프리캐스트 포스트텐션 콘크리트 넓은 보-기둥 내부 접합부의 비탄성 거동

황재환,최윤철,김영찬,김대중,임재형,권기혁,문정호,이리형 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

The purpose of this paper is to evaluate the response of Precast Prestressed Concrete Interior Wide Beam-Column Joint subjected to cyclic lateral loading. To this end, the experimental investigation was performed with six half-scale specimens of interior connection. The design parameters are the beam to column depth ratio, and the number of tendons within column core. One of the specimens, IJH-6, is modeled for the connection at the top floor of a structure. The test results showed that the specimens sufficiently resist up to limiting drift ratio of 0.035 in accordance with the provisional standard by ACI of acceptance criteria for concrete special moment frames.