• Title/Summary/Keyword: relativity

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Gravitational-wave detection - for the new age of astronomy (중력파 검출 - 새로운 천문학의 시대를 위하여)

  • Oh, John J.
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.58.1-58.1
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    • 2015
  • Gravitational-wave has been predicted by Einstein's general relativity in 1916, but its direct detection has failed to date despite of the persistent efforts in the last fifty years in the ground-based gravitational wave detectors. In the centennial year of the birth of general relativity, 'advanced LIGO', one of the most promising Earth-based gravitational wave detectors, plans to start commissioning for the successful discovery of gravitational waves. In addition, a pathfinder satellite of eLISA project, a space-based GW antenna by European Space Agency (ESA), will be launched in the mid of this year. In this talk, we review the current status of gravitational waves detection experiments and discuss its scientific impacts and the possibility of opening the new age of astronomy.

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General Relativity and Modern Cosmology (일반상대성이론과 현대우주론)

  • Hwang, Jai-Chan
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.57.5-58
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    • 2015
  • We describe relations between modern cosmology and general relativity in the historical context. We reveal some ironies imbedded in Einstein's final correction of his gravitational field equation in the context of cosmology in 1917 which has apparently opened a new era of modern physical cosmology. The ugly (according to Einstein) correction term was introduced only to build a static cosmology which turns out to be in flat contradiction with observation. Somehow, however, it is the correction term which has saved the modern cosmology from the genuine creativity of nature continuously revealed by astronomical observations. Whether the present precision cosmology is also a correct one is often ignored by the practitioners but still a pressing open question left for future theoretical and observational pursuits.

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On Interpretation of Hyperbolic Angle

  • Aktas, Busra;Gundogan, Halit;Durmaz, Olgun
    • Kyungpook Mathematical Journal
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    • v.60 no.2
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    • pp.375-385
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    • 2020
  • Minkowski spaces have long been investigated with respect to certain properties and substructues such as hyperbolic curves, hyperbolic angles and hyperbolic arc length. In 2009, based on these properties, Chung et al. [3] defined the basic concepts of special relativity, and thus; they interpreted the geometry of the Minkowski spaces. Then, in 2017, E. Nesovic [6] showed the geometric meaning of pseudo angles by interpreting the angle among the unit timelike, spacelike and null vectors on the Minkowski plane. In this study, we show that hyperbolic angle depends on time, t. Moreover, using this fact, we investigate the angles between the unit timelike and spacelike vectors.

A Study on Application of Exposure System using Waterproofing Sheets of Synthetic Polymer for Rooftop (옥상용 합성고분자 시트를 애용한 지붕노출 시스템 적용에 관한 연구)

  • Lee Sang Su;Kim Su-Ryon;Kwak Kyu-Sung;Oh Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2005.05a
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    • pp.179-183
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    • 2005
  • In apply roof waterproof system using of synthetic high polymer sheet for rooftop measure physical performance (tension$\cdot$tearing ability, temperature relativity, heating stretch performance, junction performance, wind resistance test) by various test environment condition waterproof test of structure and performance of construction work aspect, present suitable form of construction work under these environment. Also, wish to improve durability of concrete structure as that examine in priority about adhesion method and joint junction method with waterproof out surface, and present new direction about roof system application of waterproofing method for rooftop.

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A Study on the Green Eemission Ccharacteristics of $Alq_3$ ($Alq_3$의 녹색발광특성에 관한 연구)

  • Kang, Young-Chol;Chon, Dong-Kyu;Song, Jin-Won;Kim, Young-Keun;Kim, Ju-Seung;Gu, Hal-Bon;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.957-960
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    • 2002
  • Electroluminescence(EL) from conjugated polymers has recently received great attention because polymer light-emitting diodes(LEDs) clealy have potential for applications such as large-area displays. The operation of polymer LEDs is based on double injection of electrons and holes from the elextrodes, followed by formation of excitons whose radiative decay results in light emission at wavelength characteristic to the material. In this paper, we fabricated the single layer EL device using $Alq_3$ as emitting material. According as turn on voltage could know about 5.5V in voltage-current characteristics and voltage rise, current could see that increase as non-linear. Current and ruminance can see that express similar relativity in voltage, and could know that ruminance is expressing current relativity.

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Electro-luminescence Characteristics of Nano-Structural Thin Film (나노구조 박막의 EL 특성)

  • Choi, Yong-Sung;Cho, Jang-Hoon;Song, Jin-Won;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.274-275
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    • 2006
  • A new thin film materials can be built up at the molecular level, and the relationship between these artificial structures and the properties of materials can be explored. In this paper, in order to confirm the application possibility to the molecular electronic device of the organic materials, we have investigated electro-luminescent (EL) characteristics of organic EL device using $Alq_3$, PBD as emitting material. Current and luminance can be seen that express a similar relativity in voltage and could know that luminance is expressing current relativity.

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Cultural Collage in Men's Fashion (남성 패션에 표현된 문화 꼴라쥬 현상)

  • Lee Min-Sun
    • The Research Journal of the Costume Culture
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    • v.13 no.3 s.56
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    • pp.469-480
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    • 2005
  • The purpose of this study is to analyze the meaning and the value of the cultural collage expressed in men's fashion. As for the research methodology, literary research was under taken to study psychoanalytical and socioeconomic contexts in which cultural collage has been formed. In addition, demonstrative studies in men's fashion were undertaken through the analysis of pictures. The cultural collage is defined as a phenomena of making creativity by combining cultures which have no relevance. In psychological and sociological aspects, the rise of the cultural collage is caused by multinational corporation, pluralization of identity, information society, consumer oriented production, consumer society and inundation of kitsch. On the basis of the characteristics and social backgrounds of cultural collage, the aesthetic values of men's fashion can be explained by pluralism de-generalization and relativity.

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Emission Characteristics of Multilayer Structure OLED (다층구조 OLED소자의 발광특성)

  • Chol, Young-Il;Cho, Su-Young
    • 전자공학회논문지 IE
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    • v.48 no.4
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    • pp.25-29
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    • 2011
  • Organic electroluminesencent device have been studied because of its easy fabrication and high brightness for plate panel display instead of CRT and LED. There are some device structure for full color filter system can be applicable to the full color application if the blue light organic electroluminesencent device(OELD) is developed. In this study, We have investigated electro-luminescent (EL) characteristics of organic EL device using Alq3, PBD as emitting material. Current and luminance can be seen that express a similar relativity in voltage and could know that luminance is expressing current relativity.

Preconceptions on the Reference Frame and Relativity of Motion of Grade 7 Pupils (기준계와 운동의 상대성에 대한 중학교 1학년의 개념)

  • Oh, Won-Kun;Kim, Jae-Woo
    • Journal of The Korean Association For Science Education
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    • v.17 no.4
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    • pp.373-381
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    • 1997
  • To investigate the preconceptions on the reference frame and relativity of motion, 251 of grade 7 pupils were selected. The questionnaire has 15 questions consisted of four test domains made by the researchers: object looks rest or moving in the rest frame, object looks rest or moving in the moving frame. The result shows that pupils took the observations in the moving frame for those in the rest frame, or vice versa. In addition, their answers varied according as the context of the observation differed.

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