http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
정용현,이은석,박순영,양창환,정진택,Chung, Yong-hyun,Lee, Eun-seok,Park, Soon-young,Yang, Chang-hwan,Jung, Jin-taeg 항공우주시스템공학회 2009 항공우주시스템공학회지 Vol.3 No.2
The structural analysis of liquid rocket engine was performed in the case of sinusoidal vibration load to verify structural safety. The finite element model is composed with main liquid rocket engine components, combustion chamber, turbopump, gas-generator, pyro-starter, main pipes, main valve, heat-exchanger, gimbal-mount and brackets. Natural vibration mode analysis and structural analysis for sinusoidal vibration load were performed. The natural mode frequency of liquid rocket engine is twice than that of launch vehicle. In the case of stress result of sinusoidal vibration load, the part of maximum stress has 1.4 margin, so the engine structure is safe for sinusoidal vibration load.
방위산업의 시장구조 결정요인이 기술혁신과 시장지배에 미치는 영향
정용현,Chung, Young-Hyun 대전대학교 군사연구원 2007 군사학연구 Vol.5 No.-
This study examines the relationship of the industry-specific factors that effect innovation of manufacturing technology and the market share within the defense industry. Since the establishment of the basic defense industry framework in 1973, there were numerous interactions of the industry-specific factors of the defense industry structure with the technological innovation and market organization of the defense industry. During last three decades, the domestic defense industry has achieved the considerable level but the framework of the basic system has not developed much in areas of the military science and the defense manufacturing technology. Industry-specific factors were formed in the process and appeared in a variety of behavioral characteristics as subsystems. Currently, there IS a growing trend where the management of defense industry is gradually deteriorating due to limitation of the domestic industry-specific factor (e.g. defense technologies, amount of demand, etc.). If there is a prominent imbalance of the industry-specific factors. it can trigger the potential problem of conflict, lack of cooperation and control, slowing the growth of the manufacturing technology thereby diminishing the market and deteriorating the defense supply/demand relationship. In a research conducted by Joe S. Bain, Bain analyzed the relationship of the traditional industrial organization where industry-specific factor(S) not only impacts the conductor(C). And, conductor(C) influences the shaping of the performance(P) of relationship of the traditional industrial organization. Consequently, the researcher has identified the demand monopoly, barriers to entry, and market competition with comparison of defense industry issues. These defense issues were three industry-specific factors identified, which are 1) The demand monopoly and The entry barriers to new market competition, 2) the industrial technical factor to a production technical competitiveness and a market sharing competitiveness, 3) the probability factor to revolution for military affairs(RMA) and a R&D production. According to baseline with these factors, the following research model is established from the special companies group(Group A), the systematization companies group(Group B), and the general companies group(Group 0. The hypothesis is that if there are more industry-specific factors, then there will be more relationships of defense industry relation statutes. This research is an empirical study on the relationship that the industry specific factors effects the innovation of manufacturing technology and the shaping of the market in the defense industry. Moreover, the existing models to evaluate the industry specific factors of the defense industry IS much to be desired with the controlled statistical analysis of the result. It is vital to study on current situation with suggesting alternative strategy to the efficient strategy. The descriptive analysis approach analysis is conducted with SPSSWIN to conduct reliability test, factor analysis, correlation analysis, cross-tabulation analysis, one-way ANOVA, and multiple regression analysis. However, there were some limitations of the survey such as the rigidity of concept about the technical factors and various market management factors. The wishes is that the decision-maker could be utilized these defence industrial factors to formulate efficient defence policy and strategy in the future.
곽승준(Seung Jun Kwack),김순선(Soon Sun Kim),최요우(Yo Woo Choi),이규식(Gyu Seek Rhee),손경희(Kyung Hee Sohn),이이다(Rhee Da Lee),채수영(Soo Young Chae),정용현(Yong-Hyun Chung1),유일재(Il Je Yu1),박귀례(Kui Lea Park) 한국독성학회 2004 Toxicological Research Vol.20 No.2
3-Monochloro-1,2-propanediol(3-MCPD) is a toxic compound, often present in different foods containing acid hydrolyzed(AH) protein, like seasonings and savory food products. The purpose of the present study was to investigate the effects of 3-MCPD on male fertility, sperm and testosterone secretion. In vivo male fertility test was performed for observing the adverse effects of 3-MCPD on the function of male reproductive system and pregnancy outcome. 0.01, 0.05, 0.25, 1 and 5 mg/kg b.w. of 3-MCPD was given daily by gavage to groups of 15 adult male SD rats for 4 weeks. At the end of pre-treatment period, males were mated overnight with normal females. Following morning, males demonstrating successful induction of pregnancy were sacrificed on that day to assess sperm parameters and histopathology of reproductive organs. The resulting pregnant females were sacrificed on day 20 of gestation to evaluate pregnancy outcome. As a result, four-week paternal administration with 3-MCPD resulted in adverse effects on male fertility and pregnancy outcome without remarkable histopathological changes in testes and epididymides; sperm motility, copulation index and fertility index were markedly decreased in the treated group and numbers of live fetuses showed steep dose-response curves. Also, spermatogenesis was investigated in this experiment. However, no<br/> effect was observed on production of sperm in testes treated with 3-MCPD for 4 weeks. Hormone assay was performed for observing the effects of 3-MCPD on testosterone and luteinizing hormone (LH) in blood and testes of male SD rats and cultured primary Leydig cell. In result, significant changes of related hormones did not observed by treatment of 3-MCPD. These results indicated that paternal treatment with 3-MCPD induced spermatotoxic effect, which caused an antifertility on male.
실측을 통한 태양열 활용 공조기의 중간기 난방에너지 사용량 분석
장은영(Eun-Young Jang),김민수(Min-Su Kim),김동규(Dong-Gyu Kim),금종수(Jong-Soo Kum),정용현(Yong-Hyun Chung),명진필(Jin-Pil Myeong) 대한설비공학회 2010 대한설비공학회 학술발표대회논문집 Vol.2010 No.6
When the weather is between winter and spring, the change of the season, it appears cold weather like winter season lasting for a few days. Also, this year has damaged for the cold weather because of anomaly climate. For this reason, if the date of air-conditioning extended, it will be spent more energy and depended on a fossil fuel energy. In the study, the analysis of the heating energy in the change of the season through the measurement was conducted in the large space as operating AHU using a solar thermal system.
한정희 ( Jeong Hee Han ),정용현 ( Young Hyun Chung ),양정선 ( Jung Sun Yang ) 한국산업위생학회 2013 한국산업보건학회지 Vol.23 No.4
Objectives: This study was designed to establish an accurate analytical method for asbestos in a biological sample for determining occupational asbestos-related diseases and relief of the health effects of environmental asbestos. Methods: Biological samples were obtained from lungs of rats following intratracheal instillation of asbestos(Chrysotile, anthophyllite) and were prepared according to digestion method(Wet digestion, high temperature ashing, low temperature ashing). The samples were then analyzed for asbestos fibers using a transmission electron microscope equipped with an energy dispersive X-ray spectrometer. Results: Low temperature plasma ashing removed more of the organic components and reduced fiber loss compared to the wet digestion method, making specimens so prepared more suitable for transmission electron microsocpy. Conclusions: The low temperature ashing technique is the most accurate method for analyzing asbestos in biological samples.