• Title/Summary/Keyword: 장현광

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Loss and mode measurement of Ti:$LiNbO_3$ optical waveguide (Ti:$LiNbO_3$ 광도파로 손실 및 모드측정)

  • 장현수;양우석;김우경;이승태;박우정;이한영;이경식
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.02a
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    • pp.170-171
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    • 2003
  • 광도파로는 변조기, 스위치, 필터, 센서, 파장변환기 등 많은 분야에 응용이 되고 있다. 이러한 광도파로의 손실측정방법에는 프리즘 커플러를 이용하는 방법, fabry-perot 구조의 물질이 갖는 pyroelectric effect를 이용한 방법, 도파로의 입출력 단에 fiber를 커플링하여 측정하는 방법 등을 들 수 있다. 그러나, 프리즘 커플러를 이용한 방법은 미세패턴의 도파로 측정이 어렵고, pyroelectric effect를 이용하는 방법은 특정한 방향으로 도파되는 광의 측정이 불가능하며, 마지막으로 fiber 커플링 방법은 항상 같은 조건하에서의 손실 측정이 어려운 단점이 있다. (중략)

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과학기술발전과 진흥…이것부터

  • Gwon, Suk-Il;Jo, Nam-Jin;O, Jeong-Mu;Lee, Eun-Ung;Baek, Jang-Hyeon;Park, Yeong-Ho;Lee, Gwang-Yeong;Gang, Park-Gwang;Yun, Yeong-Hun;Gwon, Sun-Chan;Kim, Dong-Han;Kim, Chang-Sik;Gwon, Seon-Rok;Kim, Gyeong-Je;Park, Taek-Gyu;Kim, Myeong-Ja;Gwon, Tae-Wan;Kim, Jin-Su;Jeong, Wan-Ho;Kim, Ju-Mok
    • The Science & Technology
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    • v.25 no.2 s.273
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    • pp.8-44
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    • 1992
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OWL Proto-type System Test Observation

  • Park, Yeong-Sik;Park, Seon-Yeop;Im, Hong-Seo;Choe, Jin;Jo, Jung-Hyeon;Lee, Jeong-Ho;Jin, Ho;Bae, Yeong-Ho;Mun, Hong-Gyu;Choe, Yeong-Jun;Park, Jang-Hyeon
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.71.1-71.1
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    • 2013
  • 한국천문연구원은 우주물체 전자광학 감시체계 기술개발 사업을 통해 자국위성의 추적감시를 위해 0.5m 광시야 감시관측소 국제 네트워크(OWL : Optical Wide-Field patroL)를 구축할 예정이다. OWL 시스템의 설계 검증을 위해 시험모델을 개발하였고, 연구소 내에 테스트베드에 설치하여 종합적인 테스트를 수행하고 있다. 2012년 11월 상세설계 검토회의(CDR)를 수행하여 해외 설치할 서브시스템들의 설계를 확정 하였다. 현재 테스트 베드에서는 마운트와 컨트롤 시스템의 성능을 시험하기위해 10인치 RC 대체 경통으로 테스트 관측을 수행하였고, 3월에 납품한 proto-type 경통을 부착하여 시험관측 중에 있다. 시험 관측으로 획득한 영상들과 시스템의 개발 진행사항을 논의 하고자 한다.

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Magnetic and Magneto-Optic Properties of Tb/Fe Multilayers (Tb/Fe 다층박막의 자기 및 자기광 특성)

  • 이장로;장현숙;김미양;이용호;손봉균
    • Journal of the Korean Magnetics Society
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    • v.2 no.2
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    • pp.125-131
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    • 1992
  • 기판회전 테이블이 부착된 DC, RF-magnetron sputtering 장치로 유리기판 위에 제작한 1000 .angs. 정도의 8.8 .angs. Tb/X .angs. Fe (X=5.4~11.0) 다층박막에 관하여 시료진동형 자 기계와 타원편광 분석장치를 사용하여 자화, 수직자기이방성, kerr 회전각의 Fe층 두께와 열처리 온도 의존성이 연구되었다. Fe층 두께가 7.8 .angs. 기점으로하여 자화용이축의 전이가 나타나기 시작하여 6.4 .angs. 일때 수직자기이방성을 나타낸다. 실험치로부터 계산한 Fe와 Tb층의 경계면 수직이방성 에너지 $K_{s}$ = -0.38 erg/$cm^{2}$이고, Fe층만의 체적수직이방성 에너지 $K_{v}$ = -8.50 * $10^{5}$ erg/$cm^{3}$이다. Polar Kerr 회전각은 Fe층 두께 7.8 .angs. 에서 그대값 2 .THETA. $_{k}$ = 1.22 .deg. 를 갖는다.다.다.다.

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우주물체 전자광학 감시체계 (OWL) 광학계 개발현황

  • Han, Jeong-Yeol;Han, In-U;Na, Ja-Gyeong;Jang, Jeong-Gyun;Mun, Il-Gwon;Park, Yeong-Sik;Choe, Yeong-Jun;Park, Jang-Hyeon
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.223.1-223.1
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    • 2012
  • 우주물체 전자광학 감시체계(OWL: Optical Wide-field Patrol)는 지구상에서 빠르게 이동하는 우주물체를 신속하고 정확하게 관측할 수 있는 광학 감시체계이다. 이 체계의 임무를 완수하기 위한 광학계는 약 2도 이상의 광시야, 충분한 광량 확보를 위해 직경 500 mm 이상의 주반사경(primary mirror), 광학적 능률향상을 위한 25% 이상의 투과율, 운반 및 진동에 의한 영상성능 저하를 보정하기 위한 부반사경 구동기능, 빠른 경통 회전속도에 의한 광학 및 광기구 구조물의 안전성 확보를 위한 작은 F-수 확보 등 주요 요구조건을 만족해야 한다. 본 논문에서는 OWL 광학계의 요구조건을 만족하는 광학계의 광학 및 광기구 설계 등 개발현황을 소개하고자 한다.

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Yeoheon Jang Hyun Gwang's Design of Self-organization for Completion of Confucian Truth (여헌(旅軒) 장현광(張顯光)의 실학적(實學的) 설계(設計) - 『역학도설(易學圖說)』과 위기지학(爲己之學) -)

  • Yoo, Kwon Jong
    • (The)Study of the Eastern Classic
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    • no.49
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    • pp.7-38
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    • 2012
  • This study is an argument that Yeoheon Jang Hyun Gwang's Yeok-Hak-Do-Seol has been on the context of the typical Confucian methodology of self-organization for a sage's or superman's character (爲己之學) and completed the methodology. Therefore the context from Confucius to Southern Song China Era is argued as a context of development and systematization of the methodology. In addition the fact that Zhuxi(朱熹) and his students had systimatization of the methodology with the publications of some important textbooks is also explained. The most stressed thing of this study is Yeoheon's Yeok-Hak-Do-Seol is just the text that succeeded them as the methodology of self-organization and had a special purpose of completion of the methodology not only with comprehensive items of practice but also intuition into the human's life and the world by his mastery of Yeokhak(易學). The viewpoint this study keeps is the Confucian methodology of self-organization is considered for the purpose of development and upholding the Confucian truth, and thus the methodology itself has been regarded as the necessary one that is the closest approximation to a pursuit of Confucian truth. According to this viewpoint we can observe the features of methodology of the pursuit of Confucian truth from the Yeok-Hak-Do-Seol. However the Yeok-Hak-Do-Seol has its purpose merely on a human being's self-organization but also on an enormous enterprise to make the universe peace or sustainability of the world. His stress on the enterprise shows that his methodology is not a merely repetition of the tradition of the Zhuzixue but a creative deveopment of the tradition. The other feature is that his methodology is systematization on the basis of Yeokhak, or the study of Yi-jing(易經). The main method he intensified is easiness and simplification that is the main point which he extracted from Yi-jing as the most important and necessary way of life.

People's heart-and-mind and the righteous principle in the hostile of circumstances / focusing on Yeheon's Record of Taking Refuge (난중(亂中)의 인심(人心)과 의리(義理) - 여헌(旅軒) 장현광(張顯光)의 『용사일기(龍蛇日記)』를 중심으로 -)

  • Jeon, Byoung-Ok
    • (The)Study of the Eastern Classic
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    • no.57
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    • pp.9-40
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    • 2014
  • This article focuses on Yeheon's consideration and solution for the hostile of social circumstances during the time of the Japanese invasions. Yeheon thought that the Chosun dynasty must have faced such disorder before the war happened. People including the king and his subjects did not live their life according to the righteous principle, and the state was not under control in a way that it should accomplish the Dao. Yeheon thought that the Japanese invasion, which is more like a flood or certain disasters, was not primarily responsible for the harshest of environments. Yeheon paid his attention to the fact that even after the Japanese invasions ended, people were still in disorder losing their mind-and-heart. People's mind-and-heart became that of animals because of starvation and disease. This is because the government made people trapped in a difficult situation by forcing them to prepare for military operations, rather than taking care of them. As a result, in Yeheon's view, the main cause of the social disorder was people's lack of mind-and-heart, which brought about their actions of brutality like those of animals. Although Yeheon himself did not form righteous armies, he instead suggested a right path to overcome and solve the social disorder by describing and analyzing in detail the reality of the war as well as the problems of policies. In particular, Yeheon studied the Zhou yi at the time because understanding the principle of fortune and misfortune, as well as the rise and fall of a state, could give a proper solution to the social turmoil of his times. In Yeheon's eyes, the most important thing to do in the time of people's losing mind-and-heart was to follow li and accomplish the Dao in their daily life. And this was what he, as a gentleman, should do. Yeheon thought that in spite of the harshest of environments, one can still preserve one's grace and dignity, which would overcome one's adversity. This gives us the following questions: should one put aside one's grace and dignity to overcome wartime perils? Or in so doing, one should face more severe time after a short period of peace and stability? These questions concern the relationship between one's morality and the state's responsibility, and what is the right way of doing one's duty to the state is the main philosophical subject in this article.

IMAGING OBSERVATION SYSTEM USING CMOS IMAGE SENSOR (CMOS 영상센서를 이용한 영상관측장비 활용)

  • Jin, Ho;Park, Young-Sik;Park, Jang-Hyun;Yuk, In-Soo;Seon, Kwang-Il;Nam, Wook-Won;Han, Won-Yong;Lee, Woo-Baik;Lee, Sung-Woon;Shin, Young-Hoon
    • Journal of Astronomy and Space Sciences
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    • v.18 no.3
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    • pp.231-238
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    • 2001
  • A prototype CMOS (complementary metal oxide semiconductor) imaging system has been built and the possibility of applying to the application to astronomical observations has been investigated. The CCD (charge coupled device) image sensor has been the mainstay of image capture and astronomical imaging for the last 30 years, but CMOS devices have shown rapidly increasing success and have been adapted to many commercial imaging systems . Although the photometric performances and system noise of CMOS sensors are lower than that of CCD image sensors, CMOS Imaging system can be used to obtain general image capture for astronomical applications.

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Yeoheon's Recognition of Geography and the Significance of the Compilation of Geographical Records by His Disciples (여헌(旅軒) 장현광(張顯光)의 지리인식(地理認識)과 문인(門人)들의 지지편찬(地誌編纂) 의의)

  • Choi, Wonsuk
    • (The)Study of the Eastern Classic
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    • no.49
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    • pp.73-107
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    • 2012
  • Yeoheon Jang Hyeongwang(1554-1637), one of the greatest Mid-Joseon Confucianists did systematic studies on universe and nature. It can be considered that he inherited the academic tradition of Cho Sik (曺植) and Jeong Gu(鄭逑) and followed their steps of fengshui (風水) and compilation of geographical records. His living and thought and deserve researching with regard to geographical studies. This paper attempts to analyze Yeoheon's recognition of geography in general. In other words, I shall prove that his view of geography is Neo-Confucian. At the same time, I shall discuss how he named people's residence, how he understanded the Joseon territory, what he thought about fengshui, and what significance the complication of geographical records by his disciples had. Yeoheon considered that land is composed of water, fire, earth, and rock, and understanded the land according to the theory of Zhouyi (周易). He analyzed geographic environments by the system of Zhouyi. His study of geography is basically intended for practical use, and as a result is necessary for people to choose where to live and where to cultivate. In his opinion, it is essential to divide the land of the Joseon by means of geographical differences in order to help people to find a better place to live. We can see his Confucian view from the fact that he placed a greater emphasis on human beings over nature. Therefore, the practical use for humans is the first priority in his study of geography. Meanwhile, he considered nature itself as only the object of study. He realized the vitality of life by making a close observation of nature and attained the mind of the Heaven and Earth in a detached way. He, as a follower of Neo-Confucianism, enjoyed the land by feeling comfortable with his present status and by being satisfied with himself. He put his Confucian view of universe and world into practice in his life. As a part of his efforts, he named his residence and surrounding natural environments with the polar star and 28 stars, and accordingly they are reconstructed in a system of universe. The Confucian tradition of dongcheon gugok (洞天九曲) starting with Zhu Xi's administration of wuyi jiugu (武夷九曲) was widely prevalent during the Joseon period, but Yeoheon's system of organizing places is original. His sense of naming places reflects his ideas of following his predecessors, comparing natural objects to human emotions, and desiring to live in retirement. Yeoheon understanded the Joseon territory with comparison of the Chinese land. He expressed his knowledge in the form of changing geographical features of a district, appreciating natural beauty, locating towns, and being familiar with a region, and proposing his own climatology and view of the reality. His recognition of the Joseon territory resolves itself into the following several points. He regarded the Joseon territory as one organism, and considered the territory to be composed of ki (氣) as Neo-Confucianists usually do. In addition, he understanded not only natural environments but also towns from a perspective of the fengshui and adopted a comparative methodology in dividing regions. He also applied climatology to analyze persons and customs. He employed the methodology of fengshui from the comprehensive theory of the Yijing. It is because he was influenced by Cho Sik and Jeng Gu. Yeoheon chose dwelling places for people, or gave advice on several places of his hometown relying on his knowledge of fengshui. When it comes to his theory of fengshui, he agreed with the theory of topography with regards to the fengshui of tombs, but criticized the custom of delaying funerals in order to turn fortune in one's favor. In addition, he accepted that it is necessary to complement a town by creating forests around it. We need to pay attention to the fact that Yeoheon's disciples complied several geographical records. It proves that they inherited the tradition of "valuing practical use and governing on behalf of the people" from Cho Sik and Jeong Gu. Yeoheon put a great emphasis on geographical records and encouraged his disciples to compile them. In other words, he emphasized that they, as administrator or intellectual, need to be erudite in the history and custom of a region where they have lived, and have to establish a standard to encourage or warn people in the region while considering the geographical records. His opinion functioned as a guideline for his successors to compile geographical records later. This paper only analyzed several facts with regard to Yeoheon's knowledge of geography and an academic tradition concerning the study of geography. In the future, I shall discuss how his predecessors and successors understanded geography and how the tradition of compiling geographical records was transferred and developed between them. I believe that this study will contribute to establishing the history of geography, which the Joseon Confucianists researched for a long time but we have not paid an enough attention to until now.

The Synthesis of $Nb_2Zr_6O_{17-x}N_x$ : A New Visible Light Oxynitride Photocatalyst ($Nb_2Zr_6O_{17-x}N_x$의 합성 : Oxynitride계 신규 가시광 광촉매)

  • Kanade, K.G.;Baeg, Jin-Ook;Kale, B.B.;Lee, Sang-Mi;Moon, Sang-Jin;Lee, Chul-Wee;Chang, Hyun-Ju
    • Transactions of the Korean hydrogen and new energy society
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    • v.17 no.1
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    • pp.55-61
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    • 2006
  • 신규 $Nb_2Zr_6O_{17-x}N_x$ 광촉매를 고상합성법처리(solid state synthesis) 후 암모니아가스($NH_3$)에 의한 기상처리법(ammonolysis)으로 합성하였다. 합성된 신규 광촉매 및 이를 다시 Pt 및 $RuO_2$를 도핑 하여 $H_2S$를 광분해하여 수소를 발생 실험을 수행하였다. 이 신규 oxynitrid계 광촉매는 가시광하에서 $H_2S$를 광분해하여 수소를 발생하는(Quantum yield = 13.5 %) 우수한 광촉매 활성을 보여주었다.