• Development and Reproduction
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• v.9 no.1
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• pp.43-48
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• 2005

Bone marrow stromal cells, a constituent of the niche for hematopoietic stem cells in bone marrow, provide various factors involved in the fate decision of the hematopoietic stem and progenitor cells. Radiation, a widely used anti-cancer therapy, provokes side effects including the damage of the blood cells. Therefore, it is necessary to recover the blood cells shortly after radiation via promoting the differentiation of hematopoietic cells. In this study, we screened genes modulated by radiation in human bone marrow stromal cells in order to understand the mechanism involved in hematopoiesis after radiation. We performed differential display method by using polymerase chain reaction(PCR) and agarose gel electrophoresis. We found plasminogen activator inhibitor-1(PAI-1) was consistently induced by radiation. The significance of the PAI-1 gene modulation is to be determined.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.573-585
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• 2018

Services for navigation and entertainment through AI-based voice user interface devices are becoming popular in the connected car system. Given the classification of VUI agent developers as IT companies and automakers, this study explores attributes of agent persona and user experience that impact the driver's perceived safety and satisfaction. Participants of a car simulator experiment performed entertainment and navigation tasks, and evaluated the perceived safety and satisfaction. Results of regression analysis showed that credibility of the agent developer, warmth and attractiveness of agent persona, and efficiency and care of the UX dimension showed significant impact on the perceived safety. The determinants of perceived satisfaction were unity of auto-agent makers and gender as predisposing factors, distance in the agent persona, and convenience, efficiency, ease of use, and care in the UX dimension. The contributions of this study lie in the discovery of the factors required for developing conversational VUI into the autonomous driving environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.258-264
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• 2018

This paper presents application of a differential search (DS) meta-heuristic optimization algorithm for optimal operation of a micro grid system. The DS algorithm simulates the Brownian-like random-walk movement used by an organism to migrate. The micro grid system consists of a wind turbine, a diesel generator, a fuel cell, and a photovoltaic system. The wind turbine generator is modeled by considering the characteristics of variable output. Optimization is aimed at minimizing the cost function of the system, including fuel costs and maximizing fuel efficiency to generate electric power. The simulation was applied to a micro grid system only. This study applies the DS algorithm with excellence and efficiency in terms of coding simplicity, fast convergence speed, and accuracy in the optimal operation of micro grids based on renewable energy resources, and we compared its optimum value to other algorithms to prove its superiority.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.249-257
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• 2009

The purpose of this study is to find a classification method with high accuracy in regard with sasang constitutional diagnosis. The BMI, blood pressure, pulse wave, and Sasang constitution diagnosed by a specialist was collected from 2848 subjects who were apparently healthy. Through a selective procedure, the data of 1635 subjects was used in the analysis. The results with the classification methods such as the discriminant analysis, regression, decision tree and neural network were compared with the diagnosis of a Sasang constitutional specialist. In result, the discriminant analysis method was hard to qualify the assumption of the equality of covariance matrices within constitutional groups. Moreover, without BMI, the decision tree and neural network methods were very sensitive to the change of the analysis data. Therefore, the Logistic regression and the decision tree is recommended on condition that the decisive factors of constitution are well concerned.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.1051-1066
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• 2000

According to the recent advances of digital encoding technologies and computing power, large amounts of multimedia informations such as image, graphic, audio and video are fully used in multimedia systems through Internet. By this, diverse retrieval mechanisms are required for users to search dedicated informations stored in multimedia systems, and especially it is preferred to use contents-based retrieval method rather than text-type keyword retrieval method. In this paper, we propose a new contents-based indexing and searching algorithm which aims to get both high efficiency and high retrieval performance. To achieve these objectives, firstly the proposed algorithm classifies images by a pre-processing process of edge extraction, range division, and multiple filtering, and secondly it searches the target images using spatial and textural characteristics of colors, which are extracted from the previous process, in a image. In addition, we describe the simulation results of search requests and retrieval outputs for several images of company's trade-mark using the proposed contents-based retrieval algorithm based on wavelet.

• Journal of the Korean Society for information Management
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• v.37 no.2
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• pp.225-249
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• 2020

The purpose of this study is to identify and systematize various facet elements required by users in fiction search situations from book tags to improve the fiction search environment. Based on the Ranganathan's PMEST formula, the basic facet system of the fiction was defined as 1) the personality that forms the fiction material, 2) the content and external characteristics that compose the fiction, 3) the reader interaction with books, 4) spatial information related to fiction and reading activities, and 5) time information related to fiction and reading activities. Out of approximately 310,000 tags assigned to 7,174 fiction, 3,730 core tags were selected and content-analyzed. As a result, various attributes were systematized around the top 25 categories of the fiction facets. The results of this study can be applied to facet navigation of OPAC and fiction DB in the future.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.143-149
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• 2007

영상은 동적인 시각 이미지와 청각의 결합에 의해 감성적인 반응을 유도한다. 다양한 영상 기법을 통하여 감성적 반응의 극대화를 추구하는 영화는 영상의 시청각적 요소들을 감성의 관점에서 효과적으로 설계하는데 본보기가 된다. 그러나, 제품의 설계속성들에 대한 감성적 평가결과를 모형화하는 감성공학적 관점에서 볼 때 영화는 시청각적 자극의 수준이 극히 다양하고 동적인 경험재로 모형화의 어려움이 있다. 본 연구에서는 영화의 감성 모형을 구축하기 위한 사전연구의 단계로 영화에서의 시청각적 요인들을 문헌조사를 통해 수집, 정리, 선별하고 이러한 시청각적 요인들 중에 영화를 관람하는 관객의 감성적, 인지적 반응에 영향을 주는 유효한 요인들을 객관적이고 체계적으로 탐색하고자 하였다. 이를 위해, 감성 및 인지적 반응의 변화를 생체신호를 통해 측정하는 한편, 생체신호의 측정 시 사용된 영화의 시청각적 자극요인을 Video/Audio Processing방법에 의해 연속적인 수치로 정량화하였다. 생체신호와 정량화된 시청각적 자극요인을 동기화하고 통계적으로 분석함으로써, 생체신호의 반응과 시청각적 자극요인과의 인과관계를 통계적으로 신뢰성있는 수준에서 검증하고자 하였다. 생체신호를 종속변수로, 시청각적 자극요인을 독립변수로 하는 896개의 부분선형회귀모형(Partial Linear Regression Model)들 중 통계적으로 유의한 선형관계에 있는 경우의 빈도분석에 의하면, 시각적 요인들 중에는 밝기(Brightness), 대비(Contrast), 색상(Color), 움직임(Motion), 장면전환속도(Shot change Rate), 주요대상의 상대적 크기가, 청각적 요인들 중에는 Peak주파수, Peak주파수의 음량, 평균음량, 소음비(Sound-to-Noise Ratio)가 생체신호의 변화에 통계적으로 유의한 영향을 주는 것으로 나타났다. 이는, 위의 시청각적 자극 요인들은 특히 관객의 감성 및 인지적인 반응에 유의한 영향을 주는 요소로 작용할 수 있음을 시사하고 있다. 이를 토대로, 위의 시청각적 자극 요인들이 가지는 다양한 조합들을 설명변수로 하는 통계적인 영화의 감성 모형을 구축할 수 있을 것으로 기대한다.

• Communications of Mathematical Education
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• v.32 no.3
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• pp.435-453
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• 2018

The results analysis of National Assessment of Educational Achievement(NAEA) can provide various implications for teaching and learning in the school field. In this study we analyzed the deviation of NAEA achievement level-based correct-answer rate and the distribution of the responses percentages for three years from 2015 to 2017 focused on multiple-choice items. First we calculated the deviation of correct-answer rate between advanced level and proficient level and between proficient level and basic level, and then we selected the items whose deviation of correct-answer rate is more than the third quartile. We explored what the content areas, behavior areas and achievement standards of each item are and what the achievement standards and characteristics of these questions are. Based on the results of the analysis, we intended to derive implications for appropriate teaching-learning methods at each achievement-level.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.620-624
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• 2016

The Wnt/β-catenin signaling pathway is mandatory in adipogenesis. In this study, we investigated the applicability of functional materials for the treatment of obesity by examining Wnt/β-catenin pathway reporter activity related to adipocyte differentiation inhibiting with korean native plant extracts. The luciferase activity of HEK 293-TOP cells increased the reporter activity approximately 152% and 130% by treatment with Sanguisorba officinalis and Thuja orientalis, respectively. Ricinus communis were represented about 90% higher activity, two samples(Rosa rugosa and Sophorae Flos) showed 80% higher activity than the control. Three samples of plant extracts (Zanthoxylum piperitum, Pueraria thunbergiana, Solanum nigrum) were about 70% higher activity compared with the non-treated control. Cytotoxicity of plant extracts was not detected in the rat neural stem cells. These results suggest that the selected eight plant extracts are safe compounds. Our findings indicate that Wnt/β-catenin pathway reporter activity could be used for high throughput screening system. In addition, the plant extracts selected as candidates for adipocyte differentiation inhibiting may be potential therapeutic agents for obesity, it will be exploring the possibility of developing an anti-obesity materials through further experiments with selected plant extracts.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.39.3-39.3
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• 2018

외계행성 탐색시스템 운영현황과 계획을 소개한다. 2017년 관측장비 가동율은 97.4% 이며, 시스템이 설치된 3개 천문대에서 천문박명시간을 기준으로 총 10,157 시간이 연구에 할당되었고 총 7,178 시간 관측이 이루어졌다. 관측시스템의 성능개선을 위해 주경 코팅, 돔 레벨조정, 망원경 구동롤러 정렬, 주경 배플 마스크 설치 등 돔과 망원경의 기계부 업그레이드와 카메라 전자부 조정 및 앰프보드 교체 등이 이루어졌다. 관측효율 향상을 위해 1년간 관측된 약 177,000 장의 자료를 분석하여 불량자료 태깅기반을 마련했고, 시상모니터링과 관측 스크립트 코드를 개발하여 현재 관측에 적용하고 있다. 관측 자료는 각 연구 프로그램의 자료공개 정책에 따라 영상형태 또는 측광 파일형태로 이용이 가능하며, 관측로그는 홈페이지를 통해 확인할 수 있다. 2020년 10월부터 시작되는 2단계 관측 프로그램 선정을 위해 2019년 상반기에 관측제안서를 접수받아 하반기에 선정을 마칠 계획이며, 다양한 연구주제 발굴을 위해 파일롯 프로그램을 선별 지원할 계획이다.