• 천문학회보
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• 제41권1호
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• pp.35.2-35.2
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• 2016

We present a census of AGN-driven gas outflows based on the kinematics of ionized gas and stars, using a large sample of ~11,000 emission line galaxies at z < 0.3, selected from SDSS. First, a broad correlation between gas and stellar velocity dispersions indicates that the bulge gravitational potential plays a main role in determining the ionized gas kinematics. However, the velocity dispersion of the [OIII] emission line is larger than stellar velocity dispersion by a factor of 1.3-1.4, suggesting that the non-gravitational (non-virial) component, i.e., outflows, is almost comparable to the gravitational component. Second, gas-to-stellar velocity dispersion ratio increases with both AGN luminosity and Eddington ratio, suggesting that non-gravitational kinematics are clearly linked to AGN accretion. The distribution in the [OIII] velocity - velocity dispersion diagram dramatically expands toward large values with increasing AGN luminosity, implying that the launching velocity of gas outflows increases with AGN luminosity. Third, the fraction of AGNs with a signature of the non-gravitational kinematics, steeply increases with AGN luminosity and Eddington ratio, while the majority of luminous AGNs presents the non-gravitational kinematics in the [OIII] profile. These results suggest that ionized gas outflows are prevalent among type 2 AGNs. On the other hand, we find no strong trend of the [OIII] kinematics with radio luminosity, once we remove the effect of the bulge gravitational potential, indicating that ionized gas outflows are not directly related to radio activity for the majority of type 2 AGNs. We will discuss the implication of these results for AGN feedback in the local universe.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.197-199
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• 2016

최근 약 10년 동안, 인지무선환경에서 1차사용자와 2차사용자간의 스펙트럼 공유를 시장 (market) 논리와 접목시키는 연구들이 활발하게 진행되어 왔다. 즉, 1차사용자가 자신이 소유하고 있는 주파수 자원을 2차사용자에게 금전적 보상을 받고 대여하는 형태를 고려하는 것이다. 그리고, 이에 대한 시장의 평형 (market equilibrium)을 이론적으로 제시하는 것이 그 연구들의 주요 목표이다. 우리는 이 논문에서, 1차사용자들은 2차사용자들에게 자신들의 유휴 채널의 사용권을 대여 또는 판매하는데, 1차사용자들은 허용가능한 간섭의 양을 정해놓고, 2차사용자가 그 간섭의 양을 초과하게 되면 금전적인 보상을 받는 시장 모델을 고려한다. 그리고, 각 2차사용자는 자신들이 1차사용자들에게 지급할 수 있는 예산에는 제한이 있는 상황도 추가 고려한다. 2차사용자의 재화는 자유공간상에서 획득 가능한 전송률이고 1차사용자의 재화는 금전적인 순이득 (net profit)이다. 우리는 이러한 인지무선네트워크 시장을 확장된 Fischer 마켓으로 모델링하고, Eisenberg-Gale convex program을 통해 마켓 균형을 찾는 방법을 제안한다.

• 천문학회보
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• 제40권2호
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• pp.28.3-29
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• 2015

$Ly{\alpha}$ nebulae, or "$Ly{\alpha}$ blobs", are extended (~100 kpc), bright (L[$Ly{\alpha}$] ~ 1044 erg/s) clouds of $Ly{\alpha}$-emitting gas. The origin of the $Ly{\alpha}$ emission remains unknown, but recent theoretical work suggests that measuring the polarization could discriminate among powering mechanisms. we will discuss current status of $Ly{\alpha}$ polarization observations at high-redshift and our on-going survey program. We will present the first narrow-band, imaging polarimetry of a $Ly{\alpha}$ blob, B3 J2330+3927 at z=3.09, with an embedded, radio-loud AGN (C. You et al. in prep.). The AGN lies near the blob's $Ly{\alpha}$ emission peak and its radio lobes align roughly with the blob's semi-major axis. With the SPOL polarimeter on the MMT telescope, we map the polarization in a grid of circular apertures of radius 0.6" (4.4 kpc), detecting a significant (>$2{\sigma}$) polarization fraction P% in 10 apertures and achieving strong upper-limits (as low as 2%) elsewhere. The degree of the polarization map increases from P% ~ 5% at ~5 kpc from the blob center to ~20% at the outer part (~30 kpc). The detections are distributed asymmetrically, roughly along the blob's major axis. The polarization angles (${\Theta}$) are mostly perpendicular to this axis. These results are consistent with the picture that $Ly{\alpha}$ photons produced at the AGN (or the host galaxy) are resonantly scattered away from the center. Higher polarization fraction on the radio jet suggests that the gas is more optically thin along the jet than the off-axis region.

• 천문학회보
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• 제40권1호
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• pp.41.2-41.2
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• 2015

Steward Observatory has a rich and diverse program of investigations, with significant groups working on star and planet formation and astrobiology, galaxy and quasar formation and evolution, technology for adaptive optics and interferometry, computational astrophysics, and effectiveness of educational practice. To support this work, Steward operates and offers a range of observational and other facilities, including the Large Binocular Telescope, the MMT, the Magellan Telescopes, the Arizona Radio Observatory, and a suite of 1- and 2-m class telescopes. A special opportunity for IR astronomy exists with Arizona now running UKIRT. Steward Observatory astronomers would welcome the opportunity to form genuine scientific collaborations that are mutually beneficial for high-impact projects and improving the observing facilities.

• 천문학논총
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• 제30권2호
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• pp.107-108
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• 2015

In this project, all available databases of molecular and gas-dust clouds in the Galaxy were cross-identified by taking into account available properties, including position, angular dimensions, velocity, density, temperature and mass. An initial list of about 7000 entries was condensed into a cross-identified all-sky catalogue containing molecular and gas-dust clouds. Some relationships were studied between the main physical features of clouds. Finally, we prepared a complex observing program and address future work for filling in the gaps.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기설비전문위원
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• pp.67-70
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• 2005

HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environment design software, TLCALC 2001 for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient. TLCALC 2001 solved a few problems in use of the existing foreign tools and took several advantages. Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC 2001 is easy and practical, this program will be usefully applied to the environmental friendly design and construction of HVAC transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC 2001.

• 대한방사성의약품학회지
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• 제3권2호
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• pp.72-79
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• 2017

Arbutin is a hydroquinone derivative with a glucose moiety. As a tyrosinase inhibitor, it is widely used as a skin-whitening cosmetic agent for the treatment of cutaneous hyperpigmentary disorders, such as melasma and freckles. In the medical field, many studies have addressed the use of arbutin in various tumors, but the mechanism for tumor uptake of arbutin is still unclear. In this paper, we radiolabeled arbutin using radioiodine and studied its pharmacokinetics and tumor uptake via biodistribution experiments and single-photon emission computed tomography (SPECT) imaging. Radiolabeled $^{131}I-arbutin$ was stable for up to 24 h in PBS and serum. Biodistribution studies and SPECT imaging indicated high uptake of the compound in the bladder and kidneys shortly after injection. Twenty-four hours post-injection, significant deiodination was observed. Apart from high thyroid uptake, selective tumor uptake was clearly observed. The tumor-to-muscle and tumor-to-blood ratios were 26 and 9, respectively.

• 대한방사성의약품학회지
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• 제4권1호
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• pp.3-10
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• 2018

The folate receptor (FR) is a promising cell membrane-associated target for nuclear imaging of various cancers (via imaging $FR-{\alpha}$) and potentially also inflammatory diseases (via imaging $FR-{\beta}$), through the use of folic acid-based radioconjugates. However, there have been several drawbacks of previously reported radioconjugates, such as a short half-life of the radiolabel ($^{68}Ga\;t_{1/2}$ 68 min), a complex and time-consuming multistep radiosynthesis, and a high renal uptake of radiolabeled folate derivatives. The goal of this study was to develop an imaging probe by directly labeling folate with radioactive iodine without using an extra prosthetic group. The radiolabeling of folate was optimized using various labeling conditions and the labeled tracers were isolated by high-performance liquid chromatography. The in vitro stability of labeled folate was checked in phosphate-buffered saline and serum. The tumor-targeting efficacy of the probe was also evaluated by biodistribution studies using a murine 4T1 tumor model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.469-471
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• 2002

HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environment design software, TLCALC 2001 for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient TLCALC 2001 solved a few problems in use of the existing foreign tools and took several advantages. Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC 2001 is easy and practical, this program will be usefully applied to the environmental friendly design and construction of HVAC transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC 2001.

• 한국콘텐츠학회논문지
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• 제14권10호
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• pp.315-329
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• 2014

본 연구의 목적은 EBS 라디오 '어른을 위한 동화' 프로그램의 그림책 콘텐츠와 청취자를 위한 전략을 분석하여 책 읽어주기 방송 프로그램들의 콘텐츠 선정과정과 매체 전달 전략의 개선점을 마련하는 일에 도움을 주고자 하는 것이다. 이를 위하여 최근 6개월 간 방송된 그림책 콘텐츠 129권을 분석대상으로 하였다. 분석도구는 니콜라예바의 사회 미학적 접근방법에서 바라본 문학 외적, 내적 요소들이었으며 분석방법은 양적, 질적 분석이었다. 우선 문학적 요소들이 현대 문학 이론의 흐름을 잘 반영하면서 특정 관점에 대한 편향 없이 균형 있게 반영되어 나타났는가를 양적으로 분석하였다. 이차적으로 청취자를 위한 매체 전달 전략을 매체 미학적 관점에서 질적으로 분석하여 주제화하였다. 그 결과와 시사점은 다음과 같다. 문학 외적으로는 특정 시대, 저자배경, 출판사, 장르 편중현상이 드러났다. 문학 내적 요소 분석의 결과는 대체적으로 현대 문학의 흐름과 경향을 잘 반영하는 그림책들이 선정되었음을 알 수 있었다. 마지막으로 시각 매체를 청각 매체로 전환하여 전달하는 과정에서 여러 가지 전달 매체 전략을 구사하고 있음이 확인되었다. 이러한 결과들을 토대로 본 연구는 이 프로그램이 청취자들에게 풍성한 문학적 경험을 제공할 수 있도록 기존의 도서선정 관행을 개선하고 매체 전달 효과들을 더욱 세련된 전략으로 연출함으로써 디지털 시대의 경쟁력 있는 서사매체로 거듭나야 함을 제안한다.