http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
정희원,김승언,현용택,이용태,Jeong, Hui-Won,Kim, Seung-Eon,Hyeon, Yong-Taek,Lee, Yong-Tae 한국기계연구원 2001 硏究論文集 Vol.31 No.-
Silicon addition in titanium alloys generally results in solid solution hardening by silicon itself and precipitation hardening by titanium silicides. The morphology and distribution of the titanium silicides depend upon the alloy chemistry or the heat treatment condition, and play an important role in improving the mechanical properties of the alloys. In this study, the morphology and crystallographic characteristics of the titanium silicides in the Ti-Fe-Si alloy system were studied. Three types of silicides were found in the alloys; (1) interconnected chain-like silicides at grain boundary, (2) coarse silicides over im, (3) fine silicides smaller than 0.2m. Ti3Si was dominant in cast + HIP condition while Ti5Si3 was dominant in as-cast state. It is recognized that $Ti_5Si_3$$\rightarrow$$Ti_3Si$ transition occurred by the peritectoid reaction and it may be promoted by the pressure during HIP. However, in the case of the fine silicides, $Ti_3Si$ and $Ti_5Si_3$ were found simultaneously even after HIP. Such a fine silicide was found to have a crystallographic orientation relationship with matrix.
생체 친화적인 원소를 함유한 티타늄합금의 미세조직과 탄성계수
정희원,김승언,현용택,이용태,Jeong, Hui-Won,Kim, Seung-Eon,Hyeon, Yong-Taek,Lee, Yong-Tae 한국기계연구원 2003 硏究論文集 Vol.33 No.-
New titanium alloys with a low elastic modulus have been developed for biomedical applications to avoid the stress shielding effect of the artificial prosthesis. The newly developed alloys contained the transition elements like Zr, Hf, Nb, Ta which were non-cytotoxicity elements and $\beta$ stabilizers. In the present paper the elastic moduli of Ti-xM containing Zr, Hf, Nb, Ta were evaluated by measuring the acoustic velocity (PEG). The effectiveness of the alloying elements for lowering the elastic modulus was investigated. In addition, the dominant factors for the low modulus were discussed. Ta was the most effective in lowering the elastic modulus of the alloys. The effectiveness of Hf was not acceptable for decreasing the elastic modulus. The dominant factor was the lattice parameter for Zr, and the poisson's ratio for Nb, Ta, respectively.
정희원(Hui-Won Jeong),구본희(Bon-Hui Ku),차준민(Jun-Min Cha) 대한전기학회 2016 전기학회논문지 Vol.65 No.5
The temperature changes are very important in improving the accuracy of the load forecasting during the summer. It is because the cooling load in summer contribute to the increasing of the load. This paper proposes a weekend load forecasting algorithm using the temperature change characteristic in a summer of Jeju. The days before and after weekends in Jeju, when the load curves are quite different from those of normal weekdays. The temperature change characteristic are obtained by using weekends peak load and high temperature data. And load forecasted based on the sensitivity between unit temperature changes and load variations. Load forecast data with better accuracy are obtained by using the proposed temperature changes than by using the ordinary daily peak load forecasting. The method can be used to reduce the error rate of load forecast.
환경비용과 전력거래요금 차이를 고려한 한-중 계통 연계선로 경제성 분석
정희원(Hui-Won Jeong),차준민(Junmin Cha),이규섭(Gyu-Sub Lee) 대한전기학회 2020 전기학회논문지 Vol.69 No.10
The Northeast Asia Super Grid, a large-scale power line interconnection project in Northeast Asia, is being reviewed in the second half of 2017. As a result, there is increasing interest in research on the feasibility of interconnection between countries. Prior to the interconnection business, reviewing the technical and economical analysis is an essential process. This paper is based on the review of technical feasibility in 2016 on the interconnected between Korea-China to submarine cable. There is based on the result of the technical feasibility of the shortest distance (380 km) of submarine cable among several Korea-China interconnection sites of previous studies. The Interconnection between Korea and China is configured by HVDC ±500kV submarine cable. The following three variables are considered to construct the scenario and analyze the economic feasibility : CO₂ reduction effect, power price uncertainty of both countries, economic comparison with additional power plants. For the analysis, we use the four indices NPV (Net Present Value), IRR (Internal Rate of Return), B/C ratio(Benefit-Cost ratio) and CRP(Cost Recovery Period). The economical analysis of these scenarios are shown in this study.