http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Observation of long-term disappearance and reappearance of the outer radiation belt
이대영,신대규,김경찬,김진희,조정희,박미영,황정아,이용희,김경호,Lee, Dae-Young,Shin, Dae-Kyu,Kim, Kyung-Chan,Kim, Jin-Hee,Cho, Jung-Hee,Park, Mi Young,Angelopoulos, Vassilis,Hwang, Junga,Lee, Yonghee,Kim, Thomas 한국천문학회 2012 天文學會報 Vol.37 No.2
In this study we have used the data of various instruments onboard the THEMIS spacecraft to study the characteristics of the outer radiation belt during the ascending phase of solar cycle 24. The most astonishing result is that we discovered four long-term (a month or so) periods during which the belt has nearly disappeared. The first disappearance started late 2008, followed by reappearance in ~a month, and three more similar events repeated until early 2010 when the belt has reappeared. This is well revealed at 719 keV electrons, which is the currently available uppermost energy channel from the THEMIS SST observation, but also seen at even lower energies. Overall consistent features were confirmed using the NOAA-POES observations. The vanished belt periods are associated with extremely weak solar wind conditions, low geomagnetic disturbances (in terms of Kp and AE/AL), greatly suppressed wave (ULF and chorus) activities, greatly reduced storm and substorm activities (little source particle supply), and expanded plasmapause locations. The direct observations of such events shed light on the fundamental question of the origin of the radiation belt, which is the main focus of our presentation.
식용식물자원으로부터 활성물질의 탐색-XVII. 산딸나무(Cornus kousa Burg.)의 열매로부터 sterol 화합물의 분리
이대영,송명종,유종수,김성훈,정인식,김대근,박미현,권병목,김세영,백남인,Lee, Dae-Young,Song, Myoung-Chong,Yoo, Jong-Su,Kim, Sung-Hoon,Chung, In-Sik,Kim, Dae-Keun,Park, Mi-Hyun,Kwon, Byoung-Mog,Kim, Se-Young,Baek, Nam-In 한국응용생명화학회 2006 Applied Biological Chemistry (Appl Biol Chem) Vol.49 No.1
산딸나무 열매를 100% MeOH로 추출하고, 얻어진 추출물을 EtOAc, n-BuOH 및 물로 용매 분획 하였다. 이 중 EtOAc 분획으로부터 silica gel과 octadecyl silica gel(ODS) column chromatography를 반복하여 3종의sterol 화합물을 분리, 정제하였다. 각 화합물의 화학구조는 NMR, MS 및 IR 등의 스펙트럼 데이터를 해석하여, ${\beta}-sitosterol$(1), $stigmast-4-en-6{\beta}-ol-3-one$(2), daucosterol(3)으로 동정하였다. 이 화합물들은 산딸나무에서 처음 분리되었다. The fruits of Cornus kousa Burg. were extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc fraction, three sterols were isolated through the repeated silica gel and ODS column chromatographies. According to the results of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as ${\beta}-sitosterol$ (1), $stigmast-4-en-6{\beta}-ol-3-one$ (2) and daucosterol (3). They were the first to be isolated from Cornus kousa Burg.
이대영,박흥배,김진원,김윤재,Lee, Dae Young,Park, Heung Bae,Kim, Jin Weon,Kim, Yun-Jae 한국압력기기공학회 2016 한국압력기기공학회 논문집 Vol.12 No.1
After Japanese Fukushima nuclear power plant accident caused by the beyond design basis earthquake and tsunami, it has turned to be a major challenge for nuclear safety. IAEA, US NRC and EU have provided new safety design standards for beyond design basis event, Domestic regulatory bodies have also enacted guidances for licensees and applicants on additional methods related to beyond design basis events. This paper describes several evaluation methods for applying to nuclear power plants piping for beyond design basis earthquake. As a results, energy method based on the absorbed energy on nuclear power plant, deterministic method following design code and theory, experience method considering past earthquake data and information and probabilistic methods similar to probabilistic risk assessment were reviewed.
이대영,신대규,Lee, Dae-Young,Shin, Dae-Kyu 한국천문학회 2012 天文學會報 Vol.37 No.2
The radiation belt structure can be approximately reproduced by a form of diffusion equation, which takes into account the radial diffusion process as well as those in pitch angle and energy. The solution of the equation depends on several factors including initial and boundary conditions, diffusion coefficients, and plasmapause location. In this paper, we have attempted to determine a set of approximate functions for the energetic electron fluxes near the outer edge of the outer belt in terms of solar wind variable. We used the electron flux data from SST onboard the THEMIS spacecraft and determined its correlation with solar wind conditions in a systematic way. The functions were determined separately for different energy channels from ~30 keV up to 719 keV. Our determination of these functions allows us to predict the radial boundary condition for the electron flux, which can be implemented in a forecast model.
MANET 환경 하에서 멤버 노드간의 협력에 의해 분산된 인증서를 이용한 인증서비스에 관한 연구
이대영,송상훈,배상현,Lee, Dae-Young,Song, Sang-Hoon,Bae, Sang-Hyun 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.1
Ad-Hoc 네트워크 기술이 미래의 이동 인터넷 기술로서 이동통신망(Mobile Network) 뿐만 아니라 공중무선랜망(WPAN) 그리고 유비쿼터스 망 등에 광범위하게 활용되기 위해서는 개선 및 보완되어야 할 기술적인 문제들이 많다. 특히, 최근 네트워크 보안의 허점을 이용한 보안상 공격이 급증하고 있는 상황에 반하여 Ad-Hoc 라우팅 프로토콜 연구 대부분은 보안 위협 요소를 배제하고 안전한 환경을 가정한 채 수행되고 있다. 또한 Ad-Hoc 네트워크가 무선 매체 특성상 더욱 많은 보안상 위협에 노출되기 쉽고 유선에서 사용되던 보안 메커니즘을 그대로 적용되는 것이 부적합함을 고려할 때 Ad-Hoc 보안에 관한 연구는 더욱 활발히 이루어져야 할 것이다. 따라서 본 논문에서는 Ad-Hoc 네트워크의 특성을 고려하여 중앙 집중적인 인증기관이나 키 분배센터에 의존하지 않고 클러스터를 구성하고 있는 멤버 노드들 간의 협력적이고, 분산된 인증서를 이용한 인증 서비스를 제공할 수 있는 모델을 제안한다. 아울러 시뮬레이션을 통해 제안한 모델의 확장성과, 견고성을 평가해 본다. Ad-Hoc network technology is a mobile internet technology of the future that will be used widely not only in Mobile Network but also in Wireless Personal Area Network (WPAN) and Ubiquitous Network For this to occur, distributed routing protocol design, loop prevention for link information reduction in overhead for control messages and route restoration algorithm must be improved or complemented. Security techniques that can guarantee safe com-munication between Ad-Hot nodes net also be provided. This study proposes and evaluates a new authentication mechanism for MANET. The mechanism segregates the roles of certification authority to keep with the dynamic mobility of nodes and handle rapid and random topological changes with minimal over-head. That is, this model is characterized by its high expandability that allows the network to perform authentication service without the influence of joining and leaving nodes. The efficiency and security of this concept was evaluated through simulation.
이대영,민경욱,LEE DAE-YOUNG,MIN KYOUNG WOOK 한국천문학회 2000 天文學論叢 Vol.15 No.suppl2
We investigate the critical issue on how the BBF (bursty bulk flow) is related to the substorm current wedge formation. Observationally, after analysing data sets from Geotail spacecraft at near tail and many ground magnetic observatories for 9 months period of 1996, we find three BBF events that clearly occurred at the center of the wedge with region I type FAC (field-aligned current), and two other BBF events that were seen outside the wedge sector. Theoretically, we suggest that the substorm current wedge generation by BBF is most likely when the h' VB contribution is dominant in the well-known MHD $J_{II}$ expression (Vasyliunaus, 1984) or when the divergence of the cross-tail current carried by the particle's gradient/curvature drift is predominantly sufficient at the moment of the BBF arrival at near tail.
이대영,이건행,경민수,김형수,Lee. Dae-Young,Lee. Keon-Haeng,Kyoung. Min-Soo,Kim. Hung-Soo 한국방재학회 2007 한국방재학회 학술발표대회논문집 Vol.2007 No.1
In recent, the utilization of underground in urban area is increased as subway, store, and others but we have done a few studies for the inundation of underground due to flooding. So, we investigate the examples of underground inundation and the causes of inundation for flood events. And the relationship between flood characteristics and underground inundation is analyzed through the frequency of rainfall which is made by annual multi maximum series. As a result, most of underground is inundated by high frequency of rainfall. And there are some cases that the underground is inundated by low frequency of rainfall because of poor drainage system and characteristics of location.
중심성장액맥락망막병증에서 레이저검안경검사상 과형광부위에 대한 광간섭단층촬영 검사결과 분석
이대영,김동희,남우호,유승영,곽형우,Dae-Young Lee,Dong-Hee Kim,Woo-Ho Nam,Seung-Young Yu,Hyung-Woo Kwak 대한안과학회 2005 대한안과학회지 Vol.46 No.6
Purpose: To analyze the optical coherence tomography (OCT) result at the area of hyperfluorescence by scanning laser ophthalmoscopy (SLO) in central serous chorioretinopathy. Methods: We investigated sensory detachment, pigment epithelial detachment (PED), choroidal neovascularization (CNV), and retinal pigment epithelial atrophy using OCT in the area of hyperfluorescein by scanning laser ophthalmoscopy (SLO) in 29 eyes of 29 patients with CSC. Results: Of 29 eyes, no specific finding was noted in 19 eyes. Small PED corresponding to the leaking point was noted in 3 eyes, large serous PED with leaking point in 2 eyes, hemorrhagic PED in 1 eye, subretinal precipitate and PED in 1 eye, and retinal pigment epithelial atrophy in 2 eyes. Conclusions: OCT provided intuitive and objective information on the pathophysiologic state of the retinal pigment epithelial layer at the area of hyperfluorescence by SLO in CSC.
설계기준초과지진 하의 원전 배관 구조건전성 평가를 위한 변형률 기반 방법
이대영,박흥배,김진원,류호완,김윤재,Lee, Dae Young,Park, Heung Bae,Kim, Jin Weon,Ryu, Ho Wan,Kim, Yun-Jae 한국압력기기공학회 2016 한국압력기기공학회 논문집 Vol.12 No.2
Following the 2011 Fukushima Nuclear Power Plant accident, the IAEA has issued a revised version of the Nuclear Safety Standard for beyond design basis earthquake to consider the core meltdown accident. In Korea, relevant laws and regulations were also revised to consider beyond design basis earthquake to nuclear components. In this paper, CAV, an seismic damage factor that determines the restart of nuclear power plant after operating breakdown earthquake, is proposed for extension to the beyond design basis earthquake. For pipings not satisfying the beyond design basis earthquake condition, several evaluation methods are suggested, such as strain-based evaluation methods, simple nonlinear analysis method and cumulative damage evaluation method.