• Title/Summary/Keyword: flat space

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LINEAR POLARIZATION OF A DOUBLE PEAKED BROAD EMISSION LINE IN ACTIVE GALACTIC NUCLEI

  • Lee, Hee-Won
    • Journal of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.59-65
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    • 2011
  • A small number of active galactic nuclei are known to exhibit prominent double peak emission profiles that are well-fitted by a relativistic accretion disk model. We develop a Monte Carlo code to compute the linear polarization of a double peaked broad emission line arising from Thomson scattering. A Keplerian accretion disk is adopted for the double peak emission line region and the geometry is assumed to be Schwarzschild. Far from the accretion disk where flat Minkowski geometry is appropriate, we place an azimuthally symmetric scattering region in the shape of a spherical shell sliced with ${\Delta}{\mu}=0.1$. Adopting a Monte Carlo method we generate line photons in the accretion disk in arbitrary directions in the local rest frame and follow the geodesic paths of the photons until they hit the scattering region. The profile of the polarized flux is mainly determined by the relative location of the scattering region with respect to the emission source. When the scattering region is in the polar direction, the degree of linear polarization also shows a double peak structure. Under favorable conditions we show that up to 0.6% linear polarization may be obtained. We conclude that spectropolarimetry can be a powerful probe to reveal much information regarding the accretion disk geometry of these active galactic nuclei.

SPECIAL CONSIDERATION ON THE RADARSAT REPEAT-PASS SAR INTERFEROMETRY

  • Kim, Sang-Wan;Won, Joong-Sun;Moon, Wooil-M.
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.474-478
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    • 1999
  • SAR interferometry (InSAR) using the space-borne Synthetic Aperture Radar (SAR) have recently become one of the most effective tools monitoring surface changes caused by landslides, earthquakes, subsidences or volcanic eruption. This study focuses on examining the feasibility of InSAR using the RADARSAT data. Although the RABARSAT SAR with its high resolution and variable incidence angle has several advantages for repeat-pass InSAR, it has two key limitations: first, the orbit is not precisely known; and second, RADARSAT's 24-day repeat pass interval is not very favourable for retaining useful coherence. In this study, two pairs of RADARSAT data in the Nahanni area, NWT, Canada have been tested. We will discuss about the special consideration required on the interferometric processing steps specifically for RADARSAT data including image co-registration, spectral filtering in both azimuth and range, estimation of the interferometric baseline, and correction of the interferogram with respect to the "flat earth" phase contribution. Preliminary results can be summarized as: i) the properly designed azimuth filter based upon the antenna characteristic improves coherence considerably if difference in Doppler centroid of the two images is relatively large; ii) the co-registration process combined by fringe spectrum and amplitude cross-correlation techniques results in optimal matching; iii) the baseline is not always possible to be estimated from the definitive orbit information.

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The Comparison of the Characteristics Regarding Interior Spaces for TV News Centers (TV 뉴스센터 스튜디오의 실내 공간에 관한 특성 비교)

  • Kim, Dongsik;Sung, Lee-Yong
    • Korean Institute of Interior Design Journal
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    • v.24 no.1
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    • pp.197-206
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    • 2015
  • The purpose of this study is to analyze characteristic interior spaces for TV news center studio. Based on eight channels including public and comprehensive programming broadcasting stations the method for this research is to make differentiate existing relevant literature by creating analysis items for interior spaces through various case studies as well as find out characteristics of spatial forms, colors, materials, decorations, and etc. The conclusions are as follows. Firstly, spatial form of desk and ceiling are similar shapes but floor and wall are different comparing with public and comprehensive programming broadcasting stations. Secondly, preferred color for floor and ceiling is black, for wall and desk are blue and gray. Thirdly, various materials are preferred between public and comprehensive programming broadcasting stations. Fourthly, Flat and elevated floors are preferred as well as space and logos of broadcasting station are preferred for background images as decoration elements. Lastly, Soffit ceiling, desk accommodating more than 4 people, spotlight for public broadcasting stations, and architectural lighting for comprehensive programming broadcasting stations are preferred.

Development of four-equation turbulence model for prediction of mixed convective heat transfer on a flat plate (수평평판위 의 혼합대류 열전말 계산 을 위한 4-방정식 모델 의 개발)

  • 성형진;정명균
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.7 no.2
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    • pp.193-203
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    • 1983
  • The mixed convective heat transfer problems are characterized by the relatively significant contribution of buoyancy force to the transport processes of momentum and heat. Past analytical studies on this kind of problems have been carried out by employing either the conventional R-.epsilon. turbulence model which includes constant turbulent Prandtl number .sigma.$_{+}$ 1 or an extended R-.epsilon. turbulence model which takes account of the buoyancy effect in appropriate length scale equations. But in the latter case, the temperature variance .the+a.$^{2}$ over bar is approximated by a model under local equilibrium condition and the time scale ratio between velocity and temperature is assumed to be constant. These approximation is known to break down when the buoyancy effect is dominant. The present study is aimed at development of new computational turbulence closure level which can be applied to this rather complex turbulent process. The temperature variance is obtained directly by solving its dynamic transport equation and the time scale ratio which is variable in space is computed by a solution of a dynamic equation for the rate of scalar dissipation .epsilon.$_{\thetod}$ It was found that the computational results are in good agreement with available experimental data of wide range of unstable conditions.

A Study on the Regionalism in Contemporary Mexican Architecture -From the perspective of Luis Barragan & Ricardo Legorreta- (멕시코 현대건축의 지역주의에 관한 연구 -루이스 바라간과 리카르도 레고레타를 중심으로-)

  • 이일형
    • Korean Institute of Interior Design Journal
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    • no.13
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    • pp.231-237
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    • 1997
  • One of the clearest reactions against Modern architecture, and its planning ideology of comprechensive development, was the neo-Regional movement which arose at more or less the same time in serval countries. In the mid-fifties architects in Mexico started to design architectures which mixed vermacular and Modern methodology to recall traditional buildings. This popular alternative to Modernism had caught on in Mexico by the recent to become the accepted approach for the most regional building built by the Mexican architects. The regional architecture provided the continual activity, safety and economy of traditional life which was lacking in so many Modern building, while the these ages provided a cultural continuity. Anonymity of craftsmanship, but personalization of each building; enclosed wall of strong color, wide inward opening, but flat roof; emotional layouts and poetic outdoor water space, but variable massing; as it the buildings had been constructed over several years-these were the contradictory signs of neo-Regionalism. The Regional architecture has direct reference to human inhabitation and use, and it embraces mystery, poetic sense, a quality we are losing in Modern life. There is a freedom from rules, which shows up especially in an insouciant use of color, just for fuv.

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Reliability Assessment Criteria of Organic Light Emitting Diode(OLED) (유기 발광 다이오드의 신뢰성 평가기준)

  • Hong, Won-Sik;Song, Byeong-Suk;Jeong, Hai-Sung;Lim, Jae-Hak
    • Journal of Applied Reliability
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    • v.9 no.2
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    • pp.131-148
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    • 2009
  • An organic light emitting diode (OLED), also light emitting polymer (LEP) and organic electro luminescence (OEL), is any light emitting diode (LED) whose emissive electroluminescent layer is composed of a film of organic compounds. The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process. The resulting matrix of pixels can emit light of different colors. Such systems can be used in television screens, computer displays, small, portable system screens such as cell phones and PDAs, advertising, information and indication. OLEDs can also be used in light sources for general space illumination, and large-area light-emitting elements. In this paper, we develop the general guide line of the accelerated life test for assuring B10 life of AMOLED(Active Matrix Organic Light Emitting Diode) and PMOLED(Passive Matrix Organic Light Emitting Diode) which are widely used for display monitor less than 115 mm.

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The Economic Feasibility of Building-Integrated Photovoltaics System Installed on the Roof of Residential Building - Focused on Comparison with Construction Cost of BAPV System Depend on Roof Finishing Materials

  • Oh, Byung-Chil
    • KIEAE Journal
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    • v.17 no.1
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    • pp.15-21
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    • 2017
  • Purpose: This study was on the economic feasibility of BIPV system, focused on comparison with construction cost of BAPV system depend on roof finishing materials, and to suggest basic data on the construction cost. Method: Construction cost of BAPV system was calculated, by selecting asphalt single, flat type roof tile, color steel plate, titanium zinc plate as roof finishing material of residential building and by sum up each cost for roof finishing construction and cost for 3kWp-volumed PV module installation. Also, the economic feasibility was analysed quantitatively by comparing the cost for BIPV system construction, installing same volumed PV module instead of roof finishing materials. Result: 1. By installing BIPV system instead of the roof finishing material, the cost of construction falls ; about 19% in case of the titanium zinc plate, which is the most expensive, and about 11% in case of the color steel plate. 2. Reducing amount of the construction cost gets larger because of installing BIPV module instead of the roof finishing material, as the construction cost for roof finishing material gets higher ; therefore, it is more economical than BAPV system in terms of whole cost of construction.

The study of LISM using the high resolution spectra of the early types stars in the five open clusters

  • Park, Keun-Hong;Lee, Sang-Gak;Kang, Won-Seok;Yoon, Tae-Seog
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.79.2-79.2
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    • 2012
  • This study is aim to understand the distribution and the property of LISM (local interstellar medium) using the high resolution spectra of the 26 early type stars in the five open clusters ( IC 4665, Stephenson 1, Collinder 359, Roslund 5 and Collinder 70). These spectra have been observed by BOES in Bohyunsan observatory from 2009 November to 2011 Feburary, of which resolution is 45,000. We used IRAF for the data reduction (Bias subtraction, Flat-field division, and wavelength calibration) and DECH for the deriving the equivalent widths of 4 interstellar lines - Ca II K (3934${\AA}$), Na I D (5890, 5896${\AA}$) and K I (7698${\AA}$) and the column densities of those elements in LISM toward the clusters. The results of this study provide clues for better understanding of the LISM toward these clusters.

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Performance Monitoring Study of Unglazed Transpired Solar Air Heating Module (무창 기공형 태양열 공기 난방 모듈 성능 모니터링 연구)

  • Kang, Eun-Chul;Hyun, Myung-Taek;Lee, Euy-Joon
    • Journal of the Korean Solar Energy Society
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    • v.22 no.1
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    • pp.67-72
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    • 2002
  • Solar Air Systems (SAS) have unique advantages for space heating and tempering ventilation air. Air, unlike water, needs no protection against freezing nor are leaks damaging to the building structure or its contents. In contrast to glazed collector, unglazed steel solar collector may have higher efficiencies over glazed flat collector due to the absence of the glass. Therefore, the monitoring of SAS is so important to evaluate actual performance of SAS for right applications. This study is to provide a testing method with a movable test cell developed in KIER to evaluate the thermal performance of SAS based on international standard method ASHRAE 93-86, "Method of Testing to Determine the Thermal Performance of Solar Collectors". The monitoring tool used advanced technique LabVIEW 6i with portable notebook computer. Sample results have been obtained to access the performance of a reference and a target SAS module. The process and tool introduced here could be used to provide a performance verification data for future implementation study applications.

A Study on Type Analysis and the Formative Exaggeration Phenomenon in Fashion through Indexical Consideration of Delong's Theory: Focus on 16th to 20th Century Women's Costumes (Delong의 지표적 고찰에 따른 형태적 과장 현상과 유형 분석 연구: 근세.근대 복식을 중심으로)

  • Bae, Jung-Min
    • Journal of the Korean Home Economics Association
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    • v.48 no.6
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    • pp.9-16
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    • 2010
  • The formative exaggeration phenomenon, which makes the plastic space, escaping from the form peculiar to the human body, is being developed into the more diversified and abstract structure. This study analyzed the form and shape of costumes with objective attitude through the use of an oppositional concept method, which Delong presented from the formative viewpoint. Delong's theory, which was presented in this study, can be said to be one index that analyzed the form and shape of costumes. The costumes of the Renaissance Era, in which formative exaggeration is remarkable, are determinate in that they are closed and static, and can be classified into part, planer separation, and flat. The costumes of the Baroque and Rococo Eras are divided into similar formative perspectives, and can be said to be open, whole, and integrated due to indeterminate and diverse decorations. Entering modern times, the formative-exaggeration phenomenon in costumes of the Romantic Era are characterized by closed, part, and planer separation similar to costumes of the Renaissance Era. However, in the aspect of sleeve design and decoration, the characteristics of determinate and indeterminate were considered.