http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
고분자 세라믹 전구체를 이용한 반응 소결 탄화규소의 접합
이동화,김득중,Lee, Dong-Hwa,Kim, Deug-Jooug 한국분말야금학회 2008 한국분말재료학회지 (KPMI) Vol.15 No.1
Reaction bonded silicon carbide (RBSiC) is an important engineering ceramic because of its high strength and stability at elevated temperatures, and it is currently fabricated using reasonably cheap manufacturing processes, some of which have been used since the 1960s. However, forming complicated shapes from these materials is difficult because of their poor workability. The purpose of this work is to join the reaction-bonded SiC parts using a preceramic polymer as joint material. The manufacturing of ceramic material in the system Si-O-C from preceramic silicon containing polymers such as polysiloxanes has attained particular interest. The mixtures of preceramic polymer and filler materials, such as SiC, Si and MoSi, were used as a paste for the joining of reaction sintered SiC parts. The joining process during the annealing in Ar atmosphere at $1450^{\circ}C$ were described. The maximum strength of the joints was 63 MPa for the specimen joined with 10 vol.% of $MoSi_2$ and 30 vol.% of SiC as filler materials. Fracture occurred in the joining layer. This indicates that the joining strength is limited by the strength of the joint materials.
비협동 양상태 소나에서 적함 송신기의 단일 능동 신호와 해저 지형 정보를 이용한 송신기 정보 추정
이동화,남종근,정태진,이균경,Lee, Dong-Hwa,Nam, Jong-Geun,Jung, Tae-Jin,Lee, Kyun-Kyung 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.2
The bistatic sonar operations using a spatially-separated source and receiver are classified into cooperative and non-cooperative operations. In the cooperative operation, an active signal of a friendly ship is used and the source information is known previously. In the non-cooperative operation, an active signal of the enemy is used and it is difficult to find out the source information. The source information consists of the range, speed, course and frequency of the source. It gives advantage to operating bistatic sonar. This paper suggests a method of estimating the source information with geographic information in the sea and the single-ping of the enemy. The source range is given using one geographic point. And the source speed, course and the frequency of the enemy's source signal are given using two geographic points. Finally, the validity of the scheme is confirmed through a simulation study.
은퇴자의 보유자산 조기 고갈위험과 적정 자산배분에 관한 연구
이동화(Dong-Hwa Lee),김대환(Daehwan Kim) 한국자료분석학회 2023 Journal of the Korean Data Analysis Society Vol.25 No.4
본 연구는 사망률 개선효과를 반영하여 은퇴자의 보유자산 조기 고갈위험을 분석하고 그에따른 자가연금화전략 방안을 제시하는데 그 목적이 있다. 이를 위해 본 연구는 생애기간 동안매 시점별 보유 자산이 0 이하로 하락할 확률과 해당 연령까지의 생존확률을 곱한 값의 총합으로 산출되는 고갈위험을 활용하여 분석을 수행하였다. 분석결과 첫째, 사망률 개선효과가 반영될경우 고갈위험은 자산배분비중에 따라 2.59%p~8.97%p 증가하는 것으로 나타났다. 둘째, 사망률개선에 따른 고갈위험 증가폭은 원리금보장형 중심의 투자전략에서 가장 크게 나타났다. 셋째,고갈위험 관점에서 적정 위험자산의 투자 비중은 사망률 개선효과 반영 시 70%, 사망률 개선효과 미반영 시 50% 수준으로 나타났다. 넷째, 은퇴자의 연령이 증가함에 따라 예금의 투자 비중이 높을수록 자산부족확률은 빠르게 증가하였다. 대다수의 퇴직연금 가입자들이 원리금보장형중심의 투자를 하고 있는 상황에서 다양한 자산배분을 반영한 보유자산 고갈위험 시뮬레이션 분석은 추후 가입자들이 은퇴를 하고 자가연금화전략을 고려할 경우 도움이 될 것으로 기대된다. The purpose of this study is to analyze the ruin risk by incorporating the effect of mortality rate improvement and propose self-annuitization strategies. For this purpose, this study conducted an analysis using the ruin risk, which is calculated by multiplying the probability of assets falling below zero at each point in time during the lifespan by the cumulative probability of survival until that age. The analysis shows the following results: Firstly, when the mortality rate improvement is taken into account, the ruin risk increases by 2.59%p to 8.97%p depending on asset allocations. Secondly, when investments were primarily focused on principal guarantee, the ruin risk shows a significant increase as a result of mortality rate improvement. Thirdly, from the perspective of the ruin risk, the optimal investment proportion of risky assets is around 70% when considering mortality rate improvement, and around 50% when not considering mortality rate improvement. Fourthly, as retirees' age increases, the probability of asset shortfall increases rapidly when the investment proportion in deposits is high. Given that many retirees are currently invested in annuities with a principal guarantee focus, the simulation analysis of the ruin risk considering various asset allocations can provide useful insights for retirees when they consider self-annuitization strategies in the future.
영조 시기 송대(宋代) 붕당론(朋黨論)의 수용과 활용 - 주희 「여유승상서(與留丞相書)」를 중심으로 -
이동화 ( Lee Dong-hwa ) 수선사학회 2018 史林 Vol.0 No.65
This paper analyzed how the king and intellectuals understood and utilized factionalism(朋黨論) from the Song dynasty in accordance with their own beliefs during the reign of King Yeongjo(英祖, 1724 1776). This paper focused on the interpretation of Zhu Xi(朱熹, 1130 1200)’s critical essay on factionalism, the “Letter to Chancellor Liu.” Previous studies have attempted to identify the characteristics of the Joseon factionalism and theory of Tangpyeong(蕩平論) by comparing the factionalism of Ouyang Xiu(歐陽脩, 1007 1072) and Zhu Xi with that of Joseon. Such analysis, however, overlooked the flexibility of the original text as well as the intentional or unintentional distortion of the text made by the intellectuals of Joseon in the process of interpreting the “Letter to Chancellor Liu.” King Yeongjo and the scholars Park Se-Chae(朴世采, 1631 1695) and Yim Sung-joo(任聖周, 1711 1788), who were the main subjects of this study, appropriated the works of Zhu Xi with different beliefs and argued that they were the successors of Zhu Xi’s true intention respectively. As a result, it is pivotal to understand the inflections in the interpretation of the original Chinese text in order to identify the characteristics of the Joseon factionalism.