발전과 평화의 세상을 열기 위한 발걸음

문정현(토론자),이용식(토론자) 새얼문화재단 2003 황해문화 Vol.38 No.-

이젝터-펌프를 적용한 OTEC 사이클의 실험적 연구

문정현,이호생,김현주 한국동력기계공학회 2019 동력시스템공학회지 Vol.23 No.6

해수온도차발전(OTEC, Ocean Thermal Energy Conversion)은 열대 및 적도지역에 적용하기 적합하다. 그러나 계절에 따라 표층수 온도의 변동이 심한 지역에서는 해수온도차발전의 적용이 어렵다. 따라서, 해수 이외의 미활용열을 열원으로 하는 온도차발전 시스템의 연구가 활발하게 이루어지고 있다. 본 연구에서는 미활용열과 이젝터, 작동부 펌프를 사용한 온도차발전 실험장치를 제작하여 실험을 수행했다. 이젝터의 작동부에서 고압유체를 분사하면 흡입부에 저압이 형성되어 터빈에서의 전, 후단 압력비가 커져 발전량이 증가하므로 사이클 효율이 향상된다. 작동부 펌프의 유량이 증가됨에 따라 이젝터의 압력회복률 및 사이클 출력, 효율이 증가됨을 확인하였고 사이클 효율은 흡입부와 작동부 유량비 1:20에서 9.5%를 나타내었다

Left-Side Surgical Approach to Mitral Valve in Dog Cadaver Study

문정현,황병문,김대식,정선준,하용수,이기창,김남수,김민수 한국임상수의학회 2018 한국임상수의학회지 Vol.35 No.1

Mitral regurgitation is the most frequent cause of cardiac disability and death in dogs. A wide range ofmedical and surgical treatments have been used for mitral regurgitation. Surgical treatments for complete correctionof mitral regurgitation include valve repair and valve replacement, which have the advantages of eliminating orcorrecting the primary cause. Surgical treatments approach the mitral valve via right- or left-side thoracotomy. Aorticroot exposure is needed for cardiopulmonary bypass. To compare right-side and left-side approaches, 10 dog cadaverswere used in this study. Subsequently, the left-side surgical approach was used in vivo and in conjunction withcardiopulmonary bypass and cardioplegic arrest. Based on the results, and considering ease of access to the aorticroot, valve incision site, and visualization of the surgical field, a left-side approach is recommended.

실물옵션을 활용한 부동산 개발사업의 경제성 분석

문정현,임병준 한국부동산학회 2023 不動産學報 Vol.91 No.-

1. CONTENTS (1) RESEARCH OBJECTIVES The objective of this research is to explore the uncertainty and the irreversibility of the benefits of investment in the office building development project and to find that the economic analysis using real options provides investors with a tool to create direct and useful information. (2) RESEARCH METHOD An empirical analysis was conducted on the office building being developed by Company A, which is a state-owned company. The economic feasibility was analyzed using the DCF(Discounted Cash Flow) method. In an actual project, it is difficult to identify the time of when the project will be completed, and the possibilities of events which may occur are infinite. To consider such factors, an infinite number of options are respectively applied in real options in the economic analysis. The value of the option of the development project was projected along with the optimal investment time. (3) RESEARCH FINDINGS It was found in the research that in the case of European options, the economic feasibility was secured only with the NPV(Net Present Value) method. Considering the volatility of the vacancy rate, which is presumed to have the greatest impact on development projects, the project value including the options was calculated. The value of the project increased, and the economic feasibility was secured by accommodating the volatility of the future uncertainty and the strategic value of the project. 2. RESULTS The disadvantage of European options, which are used in the analysis of the economic feasibility of a real estate development project, is that European options can be exercised only on a pre-determined maturity date. To complement the disadvantage, American options which may be exercised at any time were analyzed in this research. It is explained that American options may be an alternative, which provides flexibility in decision-making by allowing more objective decision making from an investor's point of view. It was examined whether the empirical data from the analysis of Company A is applicable to actual projects. The research proposes practical measures for project developers for the investment and the implementation. The research also suggests the necessity for the qualitative review of the contribution to the public development, through decision making based on quantitative analysis. The data on the vacancy rate, which shows the profitability of the business, was obtained. The condition of the current real estate market was reflected more realistically by surveying and applying the changes in the vacancy rates over 48 quarterly periods, and the ultimate research result could be presented more reliably. A further inquiry is needed on the fact that the volatility of the vacancy rate used in this research has a significant effect on the valuation, which is left as a subject for future research.

탄화규소 (4H-SiC) 고전압 MOSFET의 소자의 질화처리된 게이트 산화막 형성 기술 연구동향

문정현,Mun, Jeong-Hyeon 대한전기학회 2010 전기의 세계 Vol.59 No.2

탄화규소 (4H-SiC) 고전압 MOSFET 소자의 질화처리된 게이트 산화막 형성 기술 연구동향

문정현 대한전기학회 2010 전기의 세계 Vol.59 No.2

대전지역 초.중.고등학교 조경시설 현황

문정현,심재성,정해준,서병기,Moon, Jung-Hyun,Shim, Jai-Sung,Bae, Jeong-Kwan,+Seo, Byung-Key 배재대학교 자연과학연구소 2002 自然科學論文集 Vol.12 No.1

The aim of this study was to analysis the landscape equipments of 42 school gardens in Taejon metropolitan city. Outdoor educational landscape equipments were found out at 10 schools out of 42 schools. The materials of main entrance were consisted of steel and stone at 19 schools. The stands at front of the main ground were existed at 21 schools. The pergolas and benches were existed at 20 schools. The living material fences were found out at 21 schools. Plant nameplates were found out at 22 schools. But the contents of the nameplates were so poor. The wetland and roof garden of the school were not existed. School landscape equipments should be introduced by the distinction of elementary school, middle school, and high school as well as by the space of the school site.

Comparison of Developmental Efficiency of Murine Somatic Cell Nuclear Transfer Protocol

문정현,노상호,정미란 사단법인 한국동물생명공학회 2017 한국동물생명공학회지 Vol.32 No.3

The Somatic cell nuclear transfer (SCNT) method can be applied to various fields such as species conservation, regenerative medicine, farming industries and drug production. However, the efficiency using SCNT is very low for many reasons. One of the troubles of SCNT is that it is highly dependent on the researcher’s competence. For that reason, four somatic cell nuclear injection methods were compared to evaluate the effect of hole-sealing process and existence of cytochalasin B (CB) on efficiency of murine SCNT protocol. As a results, the microinjection with the hole-sealing process, the oocyte plasma membrane is inhaled with injection pipette, in HCZB with CB was presented to be the most efficient for the reconstructed in SCNT process. In addition, we demonstrated that the oocytes manipulated in Hepes-CZB medium (HCZB) with CB does not affect the developmental rate and the morphology of the blastocyst during the pre-implantation stage. For this reason, we suggest the microinjection involving hole-sealing in HCZB with CB could improve SCNT process efficiency.

대전지역 학교 교정의 조경수목 식재현황

문정현,심재성,서병기 한국잡초학회·한국잔디학회 2002 Weed & Turfgrass Science Vol.16 No.2

Inhibition of Polo-like Kinase 1 Prevents the Male Pronuclear Formation Via Alpha-tubulin Recruiting in In vivo-fertilized Murine Embryos

문정현,노상호 사단법인 한국동물생명공학회 2018 한국동물생명공학회지 Vol.33 No.4

Polo-like kinase 1 (Plk1) has been known to be a critical element in cell division including centrosome maturation, cytokinesis and spindle formation in somatic, cancer, and mammalian embryonic cells. In particular, Plk1 is highly expressed in cancer cells. Plk1 inhibitors, such as BI2536, have been widely used to prevent cell division as an anticancer drug. In this study, the fertilized murine oocytes were treated with BI2536 for 30 min after recovery from the oviduct to investigate the effect of down-regulation of Plk1 in the in vivo-fertilized murine embryos. Then, the localization and expression of Plk1 was observed by immunofluorescence staining. The sperm which had entered into the oocyte cytoplasm did not form male pronuclei in BI2536-treated oocytes. The BI2536-treated oocytes showed significantly lower expression of Plk1 than non-treated control group. In addition, alpha-tubulin and Plk1 gathered around sperm head in non-treated oocytes, while BI2536-treated oocytes did not show this phenomenon. The present study demonstrates that the Plk1 inhibitor, BI2536, hinders fertilization by inhibiting the formation of murine male pronucleus.