• 천문학회보
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• 제40권1호
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• pp.74.4-75
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• 2015

We investigate the narrow emission-line ratios of 64 radio-loud (log $L_{1.4GHz}$ > 40) AGNs available in the SDSS archive, in order to examine whether there is a systematic difference in the accretion disk condition of radio-loud AGNs compared to radio-quiet AGNs and compact young radio-loud AGNs. The fluxes of narrow-emission lines, [O II], [Ne III], [O III], [O I], [Ar III], are measured for diagnostics. Based on the [O I]/[O III] and [Ar III]/[O III] ratios with photoionization models, we constrain the states of the accretion disk. We will present the results of the emission-line diagnostics.

• 천문학회지
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• 제29권spc1호
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• pp.419-420
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• 1996

The VLBI Space Observatory Program (VSOP) is a worldwide project of one radio telescope in space with many ground radio telescopes. The concerted space VLBI network enables us to reveal high resolution and high quality images of radio sources. The space radio telescope is anticipated to be launched in January/February 1997, and collaborative observations have been coordinated. The basic parameters of the system and present status are given.

• 천문학논총
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• 제20권1호
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• pp.73-83
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• 2005

On-The-Fly (OTF) observation method is developed for the efficient use of 6 M radio telescope at Seoul Radio Astronomy Observatory (SRAO). This technique, in which data and information of antenna position are recorded synchronously while driving a telescope regularly and rapidly across a field, provides more efficient use of telescope time and better calibration of the acquired data than the traditional point-to-point observation method does. For the realization of the method, we (1) added RT-Linux modules to the existing operating system, (2) replaced digital voltmeter with voltage-to-frequency converter, and (3) modified many SRAO observation programs. By observing Moon and G78.2+2.7 using this method and comparing them with previous observations, we verify the successful operation and efficiency of the OTF observation mode.

• 천문학논총
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• 제30권2호
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• pp.453-455
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• 2015

In this paper we introduce the Plasma Physics of Active Galactic Nuclei project, which is an ongoing experiment with Korean VLBI Network (KVN) and KVN and VERA Array (KaVA) to study multi-frequency polarimetric properties on parsec scales of active galaxies. The goal of the project is to improve our understanding of fundamental jet physics, especially evolution of the relativistic outflow coupled with the large-scale magnetic field. We selected six radio-loud AGN as our targets. So far we (i) detected resolved emissions regions at 86 and 129 GHz on VLBI scales, (ii) constructed 2D spectral index maps of the outflows, and (iii) found polarizations at 22 and 43 GHz for a few targets. Here we present spectral index distributions of 3C 120 between 22 and 43 GHz and a linear polarization map of BL Lac at 43 GHz obtained with KVN.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1996년도 학술대회
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• pp.101-105
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• 1996

근래에 기존의 텔레비젼이나 라디오 방송에서 영상이나 음성의 방송 외에, 할당된 주파수를 최대한 효율적으로 사용하기 위한 부가방송의 개발이 활발히 이루어지고 있다. KBS에서는 오래 전부터 데이터 방송분야의 개발에 힘써왔으며 라디오에서는 RDS를 이용한 데이터 방송이 실용화 단계에 들어가고 있다. 1995년 하반기부터 KBS 제1라디오(표준FM)를 통하여 전국적으로 RDS 시험 방송을 하고 있으며, 또한 1997년에 문자정보 서비스를 위해 한국 실정에 맞는 새로운 RDS 한글 문자정보 규격을 만들어 서비스를 할 예정이다.

• Journal of Astronomy and Space Sciences
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• 제24권4호
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• pp.297-308
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• 2007

2010년에 발사될 예정인 아리랑위성 5호의 부 탑재체인 AOPOD(Atmosphere Occultation and Precision Orbit Determination) 시스템은 GPS(Global Positioning System) 전파 엄폐(radio occultation) 자료를 제공한다. 이 논문에서는 아리랑위성 5호 궤도에서 발생하는 GPS 전파 엄폐의 발생 빈도 및 분포를 시뮬레이션하고, 현재 천문연구원에서 개발 중인 GPS 전파 엄폐 자료처리시스템인 KROPS(KASI Radio Occultation Processing System)를 사용한 전리층 전자밀도 산출결과를 제시하였다. 전자밀도를 산출하기 위해 2004년 6월 20일에 발생한 CHAMP(CHAllenging Minisatellite Payload) 위성의 GPS 전파 엄폐 관측값을 사용하였고 산출된 결과는 IRI(International Reference Ionosphere) - 2001 모델과 CHAMP 위성의 랑뮈어 탐침기(Planar Langmuir Probe) 및 이온존데 간과 비교하였다. 산출된 전자밀도를 이온존데 값과 비교했을 때, $F_2$층 최대전자밀도 고도인 $hmF_2$에서 약 5km, $F_2$층 최대전자밀도인 $NmF_2$에서 약 $3{\times}10^{10}el/m^3$의 차이를 보였으며, 랑뮈어 탐침기 값과 비교하여 고도 365.6km에서 두 값 모두 $1.6{\times}10^{11}el/m^3$로 일치하였다.

• 방송공학회논문지
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• 제22권4호
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• pp.462-472
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• 2017

네트워크 기술이 발달함에 따라, 한류 등 특정 나라의 미디어 콘텐츠가 해당 나라뿐 아니라 세계적으로 소비되고 있다. 이와 같이, 동일한 콘텐츠가 다양한 국가의 방송환경에서 소비되는 경우, 방송되는 국가 및 지역적 환경 등에 적합한 중간 광고의 삽입 및 대체방안이 필요할 것으로 보인다. 이에 본 논문에서는 ATSC 3.0에서 차세대 방송표준으로 채택한 MMT를 기반으로 하여 하이브리드 방송 환경에서의 중간 광고 삽입 방안을 제안하였다. 제안한 방안은 MMT의 MPT message 및 MMT-CI를 이용하여 시그널링을 전달하고, 이에 따라 광고 데이터를 전송하는 방식으로 중간 광고를 삽입하는 것이다. 이를 검증하기 위해 본 논문에서는 MMT의 구조를 분석하고, 제안한 방안 검증 시스템을 설계하여 실험결과를 통해 제안한 중간 광고 삽입 방안을 검증하였다.

• 한국언론정보학보
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• 제16권
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• pp.36-70
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• 2001

The purpose of this study is to investigate women's radio talk program and evaluate its possibilities and limitation from the point of feminist perspective. The theoretical framework is based on feminist studies and text analysis of talk show. Existing studies regarding talk show are mainly focused on television. But radio talk show is one of general entertainment and it's influences on minorities are still significant. is the most representative women's radio talk program in Korea. It has been broadcasted over 10 years and very popular among Korean housewives. The audience of this program call themselves schoolfellow, and call the program 'school of women'. The media text of is mainly consisted of letters from women audiences, and they are selected by producers. So the text is made by both audiences and producers. The unique combination of this process produces complicated discourses which contain women's experiences in letters and station's considerations through safekeeping. The problems investigated in this study are as follows: First, What discourses are produced in this program? Second, Alternative possibilities can be seen in this program in feminist perspectives? Text analysis of 1week(2000.9.18-9.24) and interview with producers are accomplished to this purposes. In the text analysis, subject matters, inscribed women's position, values of the letters are revealed. Most of the subject matters are family affairs. Some are socially oriented but family and home are the predominant category of women's letters. And the position of women subject is defined in the domestic network. They are nameless but the mother, wife, daughter, daughter-in-law of other people. In value, family-oriented value and small happiness in everyday life are generally appeared. But these values are essentially coincide with the values of status quo. The answers of the conflict are not public but individualized. And acception the status quo is presented as the wisest decision, But ` has many implications in relation to women's sharing of their experience, and construction of imagined community in media. Women continuously interact each other revealing and discussing their experiences and sometimes their social practices are stirred through this media sphere. So we see the 'emotional union' among women are formed through radio. The limitation of this program is very apparent: it's patriarchic values, acception of status quo, and individualization of the women's problems. But in the same time we can read coexisting it's latent possibilities: the possibilities of women's public sphere. But it is completely alternative women's sphere in feminist perspectives. It renders women opportunities to participate public media and share with other women, and collaborate with their problem.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.314-317
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• 2003

In this paper, a measurement and analysis program is developed, that can be utilized to measure and analyze radio propagation characteristics. This program is able to control the measurement instruments including spectrum analyzer through a GPIB interface, and analyze the measured data to yield mean excess delay and RMS delay spread. The measured path loss can be compared with theoretical path loss in free space or inside tunnels. The measured and analyzed results can also be presented in the forms of graphs. As those tasks can be conducted on the measurement spot, this program is very helpful for performing and verifying measurements.

• 천문학회보
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• 제44권1호
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• pp.73.3-73.3
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• 2019

A Korean VLBI Network $1^{st}$ generation key science program, the Interferometric Monitoring of Gamma-ray Bright AGNs (iMOGABA) program has revealed various natures of gamma-ray flares in active galactic nuclei (AGNs). Here in this presentation, we would like to introduce a new candidate of KVN $2^{nd}$ generation key science program, so called, the AiMOGABA (Astrometric iMOGABA), aiming at studying a wondering radio core effect of relativistic jets from AGNs with high resolution VLBI astrometric monitoring of high-energy bursting AGNs with KVN as well as a Australian millimeter radio telescope MOPRA. The introduction will include the current scientific highlights of the iMOGABA, and the overview of the AiMOGABA.