• 천문학회보
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• 제39권1호
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• pp.67.1-67.1
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• 2014

Comets are mysterious travelers from outer Solar System. It is considered that comets loose their subsurface ice once they were injected into a snow-line of the solar system, at the same time, develop adiathermic dust layers on the surface in a time scale of ~10,000 years. They eventually become inactive (see also the presentation by Yoonyoung Kim et al.). Optical similarity between comets and asteroids in comet-like orbits suggests the existence of such dormant or inactive comets supporting the evolutionary scenario. However, unforeseen accidents cast a misgiving to modify the stereotype. A periodic comet, 17P/Holmes, is known as comet with very low activity before 2007. However, the comet suddenly exhibited an outburst in 2007 October, which is known as the most energetic cometary outburst since the beginning of modern astronomy. On the other hand, another periodic comet, P/2010 V1, was not known before 2010 November probably because of low activity and discovered while it experienced outburst. We investigated the time-evolution of the magnitudes and the morphological developments based on the dynamical theory of dust grains, and derived the energy per unit mass of ~10,000 J/kg. From these observational evidences, we suggest that crystallization of buried amorphous ice (even in low-activity comets) can be responsible for the dramatic cometary outbursts.

• 천문학회보
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• 제41권1호
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• pp.70.4-71
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• 2016

The links between super-massive black hole masses and their host galaxy properties are observed, indicating that black hole growth and host galaxy evolution are closely related. Reverberation mapping, which uses the time delay from the central black hole to broad line regions, is one of the best methods to estimate masses of black holes of active galactic nuclei (AGNs). However, only masses of about 50 black holes have been determined in reverberation mapping studies so far, and most of them are limited to optical luminosities below 10^45 erg/s due to the challenges of long-term time domain observations in both photometry and spectroscopy. In this project, we expand reverberation mapping samples to higher luminosities of > 10^44.5 erg/s at 0.1 < z < 0.35, that have expected time lags of 40 - 250 light days. Photometric (using LOAO 1-m and MDM 1.3-m) and spectroscopic (using MDM 2.4-m and Lick 3-m) monitoring campaigns are being conducted for a 3 year duration and 20 day cadence. Precedent photometric observations in 2015B show some targets with variability and follow-up spectroscopic observations are on-going. In this presentation, we introduce our project, present reverberation mapping simulation results, and preliminary results on photometry. These reverberation mapping masses of relatively high luminous AGNs will provide a strong constraint on black hole mass calibration, e.g., the single-epoch mass estimation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.23.1-23.6
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• 2018

Background: Velopharyngeal insufficiency that accompanies speech resonance and articulation disorders can be managed through several intervention methods such as speech-language therapy, prosthetic aids, and surgery. However, for patients with severe hypernasality, surgical interventions are highly recommended. Among available surgical techniques, the posterior pharyngeal flap is most common. Case presentation: Two adult males with high nasalance scores underwent superiorly based posterior pharyngeal flap surgery, followed by speech testing by an expert speech-language therapist. Nasalance scores and articulation accuracy were assessed up until 1 year after the surgery. Nasalance scores were measured five times using a nasometer, after which the average value was calculated. Conclusions: Consistent declines in hypernasality over time are not easy to explain since the pedicled pharyngeal flap narrowed over time, secondary to cicatrization. However, scar tethering of the soft palate in a posterior direction could reduce the velopharyngeal port size over time. Therefore, long-term follow-up with intensive speech therapy is suggested for patients with severe hypernasality.

• 한국정보처리학회논문지
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• 제7권2호
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• pp.328-336
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• 2000

본 논문에서는 사용자가 멀티미디어 문서를 쉽게 제작할 수 있고, 실행시 동적 프리젠테이션을 지원할 수 있는 멀티미디어 저작 시스템을 제안하고 있다. 본 시스템의 특징으로서는 미디어간의 시간 관계를 인과 관계를 바탕으로 새롭게 정의함으로서 실행 중에 발생될 수 있는 미디어들의 실행 시간 변경을 효과적으로 처리하고 있다. 또한, 멀티미디어 문서 저작중 발생될 수 있는 일관성 오류를 즉시 검증하여 피드백하는 동적 저작 기능을 지원하고 있다. 본 저작 시스템에서는 저작내용이 파싱 단계를 거치면서 트리 형태의 내부 구조로 표현되고 있으며, 실행 시간에 동적 프리젠테이션과 사용자 상호작용을 지원하기 위한 프리젠테이션 엔진이 개발되었다.

• 한국콘텐츠학회논문지
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• 제8권12호
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• pp.222-235
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• 2008

본 연구는 인터뷰 자료를 분석하는 질적 방법을 통하여 창조계급을 이루는 UCC 이용자의 이용 동기를 분석하였다. 본 연구의 결과 동영상 UCC 이용자는 심심풀이 이용자와 능동적 조회자 그리고 창조자로 구분되었다. 연구의 결과 UCC 이용자들의 동기요인으로 일상생활에 도움이 되는 정보공유, 보여주고 싶다라는 자기 표현감, 다른 사람과의 소통 욕구, UCC가 자기표현을 쉽게 하도록 도와주는 용이성, 유용성이 능동적 조회자와 창조자들에게서 발견되었다. 기술적 용이성은 창조자의 경우에만 동기요인이 되고 있다. 즐거움은 단순조회, 심심풀이, 창조자를 막론하고 중요한 UCC 이용 요인으로 나타났다. 조회자 중에도 시간가는 줄 모르고 빠져드는 경험을 하거나 자신의 목적과 흥미에 따라 UCC 종목을 선택하기도 하는 경우가 드러났다. 그러나 즐거움이나 흥미의 내용은 창조자의 경우 창조의 기쁨, 플로우라는 특수한 즐거움으로 나타났다. 본 연구의 결과 이제까지 기술수용모형 (TAM)이나 감정모형 (PAD) 등을 이용한 UCC 이용자 연구의 결과를 보완하고 기존 연구에서 깊이 다루어지지 않은 창조의 기쁨, 플로우가 콘텐츠 창조자의 중요한 추동 요인이 된다는 점이 부각되었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.488-490
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• 2012

오늘날 QoS/QoE 기술의 일환인 HTTP를 활용한 동적 적응적 스트리밍 기술이 이슈화 되고 있다. 본 논문에서는 HTTP를 활용한 동적 적응적 스트리밍 기술에 대해 연구하였다. 이를 기반으로 HTTP를 활용한 동적 적응적 스트리밍 시스템을 설계 및 구현하였다. 본 시스템에서는 MPEG2-TS 파일에 대해 비트율별 변환, 일정 시간 별 Segment의 분할, 앞에서의 파일들을 참고하여 최종적으로 전송에서 활용되는 MPD(Media Presentation Description) File의 생성과 서버와 클라이언트 간의 스트리밍에 대해 HTTP를 활용한 동적이고 적응적인 네트워크 환경에서의 비트율별 스트리머로 구성된다. 이는 불특정 다수의 네트워크 환경에서 끊김없는 지속적인 영상의 재생을 위한 다양한 스트리밍 분야와 멀티미디어 분야에 활용될 것이다.

• KIEAE Journal
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• 제17권2호
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• pp.35-43
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• 2017

Purpose: The purpose of this study is to find out the characteristics of service (landfill) costs (hereinafter, the "landfill costs") applied to the dissolution promotion committee and analyze the characteristics of landfill costs at the time where the dissolution of promotion body is increasing with the authority of the head of local government regarding the territory difficult with the continuous promotion by delaying or suspending the project for a prolonged period or suspending the project through the dissolution of the project body by the promotion committee and cooperative union since the flawless promotion of the maintenance project. Method: After revising the law in February 2012, the survey and analysis is made for the status of applying landfill costs and maintenance project scale of the dissolution promotion committee not confirmed in details around a total of 20 regions, including, 9 regions of redevelopment projects completed with the advance review, 7 regions of re-construction projects and 4 regions of urban environment maintenance projects from the total of 59 regions, Result: The influence on the landfill costs is shown to be greatest in the service expenses and management and supervision on this field has significance for the maintenance project perceived as private project, rather than public project, that the public management is neglected with insufficient presentation of operation criteria and so forth that it displays the tendency to lead to the discrete operation of the project body. In order to enhance the transparency of operating costs for the projects that are led by private capital, it is required to strengthen the role of public sector through enthusiastic intervention by the public sector in standardization of operation criteria, presentation of guideline and so forth.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.237-240
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• 2005

Calibration and Validation are major element of any space borne Earth Observation Mission. These activities are the major objective of the commissioning phases but routine activities shall be maintained during the whole mission in order to maintain the quality of the product delivered to the users or at least to fully characterise the evolution with time of the product quality. With the launch of ERS-l in 1991, the European Space Agency decided to put in place a group dedicated to these activities, along with the daily monitoring of the product quality for anomaly detection and algorithm evolution. These four elements are all strongly linked together. Today this group is fully responsible for the monitoring of two ESA missions, ERS-2 and Envisat, for a total of 12 instruments of various types, preparing itself for the Earth Explorer series of five. other satellites (Cryosat, Goce, SMOS, ADM-Aeolus, Swarm) and at various levels in past and future Third Party Missions such as Landsat, J-ERS, ALOS and KOMPSAT. The Joint proposal by the European Union and the European Space Agency for a 'Global Monitoring for Environment and Security' project (GMES), triggers a review of the scope of these activities in a much wider framework than the handling of single missions with specific tools, methods and activities. Because of the global objective of this proposal, it is necessary to put in place Multi-Mission Calibration and Validation systems and procedures. GMES Calibration and Validation activities will rely on multi source data access, interoperability, long-term data preservation, and definition standards to facilitate the above objectives. The scope of this presentation is to give an overview of the current Calibration and Validation activities at ESA, and the planned evolution in the context of GMES.

• Journal of Construction Engineering and Project Management
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• 제6권3호
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• pp.8-13
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• 2016

One of the activities that are almost used by instructors to assess the undergraduate learners (students) performances in the teaching and learning system is performing researches. It's most probably that learners prepare a presentation for the research, through which they conduct their ideas to the audiences (the instructor and their colleagues). Recently, a phenomenon was monitored regarding the research preparation process practiced by the learners, that the majority go directly to the websites, in which they could easily find tons of attractive and ready-made information that fill the gaps of their heavy homework gained from several courses. It's a convenient activity for learners to go through this easy path to fulfil their duties, but the issue is that the output of such path is so weak. The gained information in this case is so shallow, loose, and could easily been evaporated after a while. There is a need to examine the impact of a missing skill in the current learners' generation: the reading practice. It's noticed that library visits to read books were strongly decreased compared with what was happening in the older generations, where the piece of information was hard to collect, but in the same time, is hard to be forgotten. As a part of the teaching and learning process, and through a college of Engineering, this study will introduce results of the comparison between the outputs of the two methods of collecting information: through the web, and through the traditional book reading. This is to highlight the importance of reading through an experiment applied on one section of students who were asked to prepare a research from a certain chapter of their textbook, and compare that with a prior research they had prepared from the websites. The results were impressive and reflected the importance of the missed reading activity.

• 디지털콘텐츠학회 논문지
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• 제4권1호
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• pp.45-55
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• 2003

컴퓨터의 성능과 정보통신의 기술이 발달함에 따라 텍스트와 이미지를 기본으로 한 배너광고에서부터 동영상 및 사운드를 활용한 인터넷 방송에 이르기까지 멀티미디어 제작 및 구현은 더욱 확산되어 가고 있다. 본 논문에서는 기존의 제작방법을 분석하여 주된 요소들과 기능들을 유출하고, 즉 객체(이미지, 동영상, 사운드, 버튼, 영역 등)들에 이벤트를 설정하고, 구동을 설정하는 주요기능을 갖는 저작도구를 제시한다. 또한 활용이 가능한 웹사이트에 구현한 결과, 주관적으로 보았을 때에 기존의 방법과는 이미지의 질(quality)에서나 로딩(loading)되는 속도에 있어서도 큰 차이를 느낄 수 없다. 제시한 저작도구는 전문가가 아니어도 누구나 쉽게 제작할 수 있는 간편한 구조로 설계한 도구이며, 웹사이트뿐만 아니라 CD-ROM 타이틀에서도 적용이 가능하며, 이미지에 마우스만 갖다 대도 음성까지 들을 수 있는 멀티미디어 배너광고, 영화장면에 마우스를 갖다 대면 대사까지 들을 수 있는 영화예고편, 자신의 음성을 녹음해 직접 보낼 수 있는 E-카드, 홈페이지 제작 등으로 활용될 수 있다. 특히, 웹사이트의 멀티미디어 배너광고의 활용은 시각적 요소를 벗어나 청각적 요소를 추가함으로서 사용자의 흥미를 더욱 유발시킬 수 있으며. 고가 저작도구와 고급 인력에 드는 비용과 시간을 절감시킬 수 있다. 또한. Intelligent Multimedia Presentation (IMMP) 기술을 응용함으로써 사용자들이 보다. 쉽게 다룰 수 있는 저작도구 개발에 기여가 될 것이다.