• Title/Summary/Keyword: Jiyoung

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Numerical Simulation of Environmental Change in South West Offshore Wind Farm Using MIKE

  • Kim, Minsuek;Kim, Jiyoung;Jeon, In-sung
    • KEPCO Journal on Electric Power and Energy
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    • v.7 no.1
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    • pp.145-152
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    • 2021
  • Environmental change due to construction of large offshore wind farm has been a debate for a long time in Korea. There are various data acquired on hydrodynamics around this area before and during construction of offshore wind farm but no data during operation could be made due to delayed schedule. In this study, environmental change such as bathymetry change and scouring was forecasted using MIKE, numerical hydrodynamics model, and its results were validated using the observation data before and during construction.

COVID_19 fake news and real news discrimination system (코로나19 가짜뉴스와 진짜뉴스 판별 시스템)

  • Lee, Jimin;Lee, Jisun;Woo, Jiyoung
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2022.01a
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    • pp.411-412
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    • 2022
  • 본 논문에서는 코로나19 뉴스와 코로나19 가짜뉴스의 데이터셋을 활용하여 입력 받은 뉴스가 가짜뉴스일 확률을 예측한다. 가짜 뉴스 본문에는 코로나19, 대통령, 정부, 가짜, 언론 등의 키워드의 빈도가 높았다. 위의 키워드를 토대로 나이브 베이즈 모델링을 하여 이를 적용해 가짜 뉴스를 가려내는 웹페이지를 개발하였다.

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Drought risk analysis based on a scenario-neutral approach considering future climate change scenarios: focused on Yongdam Dam basin (미래 기후변화를 고려한 시나리오 중립 접근법 기반 가뭄 위험도 분석: 용담댐 유역을 중심으로)

  • Jiyoung Kim;Jiyoung Yoo;Tae-Woong Kim
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.199-199
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    • 2023
  • 최근 기후변화의 영향으로 가뭄, 홍수 등 재해의 발생 빈도 및 강도가 증가하고 있다. 미래에는 온실가스 배출량의 증가로 극한 기상현상은 더욱 심화될 전망이다. 이러한 위험에 효율적으로 대비하기 위해 기후변화 시나리오를 고려하여 미래를 전망하는 것은 매우 중요하며, 최근 연구자들은 불확실성을 고려하기 위해 다양한 시나리오를 적용하고 있는 추세이다. 다만, 기후변화 시나리오를 입력자료로 하여 분석을 수행하는 경우, 새로운 기후변화 시나리오가 생성될 때 기존 기후변화 영향 평가는 무의미해지며, 기존 결과의 신뢰도 또한 감소하게 된다. 지금까지 사용된 시나리오 기반 접근법의 한계를 보완하여 시나리오 중립(Scenario Neutral, SN) 접근법이 개발되었고, 이는 다양한 기후변화 시나리오에 대한 시스템의 반응을 평가하는데 유용하다. 본 연구에서는 시나리오 중립 접근법을 활용하여 가뭄 위험도를 분석하였으며, 이를 위해 금강 유역 내 용담댐 유역을 대상으로 분석을 수행하였다. 입력자료로는 용담댐 유역의 1966~2020년 일단위 강수량 자료를 사용하였고, 문헌 조사를 통해 미래 기후변화에 따른 강수량 변화 추이를 파악하였다. 연평균 강수량의 증가와 여름 강수량의 증가를 기준으로 삼아 증가 비율에 따른 노출 공간을 생성했으며, 목표 변화에 따른 교란된 시계열을 도출해냈다. 이후, 각각의 시계열에 대한 이변량 가뭄빈도분석을 수행하여 재현기간을 산정한 뒤, 목표 변화에 따른 위험도를 비교하였다. 그 결과, 연평균 강수량과 여름 강수량이 현재와 유사한 경우 100년 빈도 가뭄이 발생할 확률은 0.84, 연평균 강수량의 증가가 110%, 여름 강수량의 증가가 115%일 경우 100년 빈도 가뭄이 발생할 확률은 0.79이었다. 추후 실제 미래 기후변화 시나리오를 적용하여 기준치에 따른 만족도를 분석한다면, 가뭄 대응에 유용한 의사결정 도구로 활용될 수 있을 것이다.

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Investigating the Effects of Meteorological Disasters on Hydroelectric Power Generation Using a Structural Equation Modeling (구조방정식모형을 이용한 기상재해가 수력발전을 통한 전력 생산에 미치는 영향 분석)

  • Kim, Jiyoung;Byun, Sung ho;Yoo, Jiyoung;Kim, Tae-Woong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.1
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    • pp.33-41
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    • 2023
  • Recently, global warming has accelerated climate change, increased extreme weather phenomena, and increased the frequency and intensity of weather disasters, leading to increasing uncertainty about the power production of new and renewable energy that is sensitive to weather. In fact, it has been reported that a number of damage to hydroelectric power generation have occurred due to weather disasters. Therefore, using the hydroelectric power generation performance data of Chungju Dam, meteorological data of Chungju Meteorological Observatory, and operation data of Chungju Dam, this study investigated the effect of meteorological disasters on hydroelectric power generation through structural equation modeling considering the number and intensity of meteorological disasters per month. The results indicated that the increased drought occurrence affected the decreased hydroelectric power generation by about 38.3 %, however the increased hydroelectric power generation could not explained by the increased flood occurrence. In conclusion, an increased drought occurrence in future may significantly influence hydroelectric power generation.

A Study on the Development of Vocabulary of Korean Children: Based on the Analysis of the Type of Words (유형별로 본 아동 어휘 발달 특성: 원어정보를 중심으로)

  • Choi Eunah;Kim Soo-Jin;Shin Jiyoung
    • MALSORI
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    • no.52
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    • pp.85-99
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    • 2004
  • The aim of this study is to show developmental characteristics of vocabulary of Korean children. In this study, words were classified according to the origin of words: pure Korean, sino-Korean and foreign words. The results of the present study are as follows: In common nouns, the rate of sino-Korean was 33.6% in 3 year-old children but 50.7% in 8 year-old children. Adverb and prenouns showed the similar rate. The rate of words with foreign origin was 10 ~ 11 % in all age groups.

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Context-based Authentication Service for The Mobile Office

  • Yang, Jiyoung;Lee, Hyundong;Rhyoo, Shi-Kook;Chung, Mokdong
    • Journal of Korea Multimedia Society
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    • v.15 no.12
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    • pp.1475-1484
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    • 2012
  • Today many companies introduce new mobile office environments evolved from the recent rapid development in mobile device technologies. Most of the recent mobile office systems use a simple authentication scheme such as ID/Password. This method is easy to use, but it does not consider the user's context. Thus it cannot provide appropriate security service required by the user's proper contexts. Therefore, this paper proposes a context based authentication system which applies security level verification and uses fuzzy algorithm based on the importance of access authority control.

Thinning Intensity for Large Diameter Trees in Korean White Pine Plantation of South Korea

  • Lee, Daesung;Seo, Yeongwan;Park, Jiyoung;Choi, Jungkee
    • Journal of Forest and Environmental Science
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    • v.33 no.1
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    • pp.74-77
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    • 2017
  • The purpose of this study is to analyze the effect of thinning intensity on the growth of large diameter trees in Korean white pine (Pinus koraiensis S. et Z.) plantation. Eight thinning plots were analyzed by categorizing into heavy thinning, light thinning, no thinning (control) according to thinning intensity. As a result, average DBH increased more in heavy thinning plots than in light thinning or unthinned plots. The number of large trees (DBH>25 cm) were obviously shown the most in heavy thinning plots. It is considered that heavy thinning is needed for the production of the large diameter trees.

A Study on Relationship Between Teamwork Skills and Big Five Personality Factors for Engineering Students (공학계열 학생들의 팀웍 스킬과 성격 5요인과의 관계 연구)

  • Han, Jiyoung;Bang, Jae-hyun
    • Journal of Engineering Education Research
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    • v.18 no.2
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    • pp.43-51
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    • 2015
  • This study had a purpose to analyze the relationship between teamwork skills and Big Five personality factors for engineering students. For the purpose, 43 engineering students attending engineering creative design course were organized 14 teams as NEO personality inventory testing before the course. The teamwork skills for engineering students was improved through engineering creative design course and the correlation between teamwork skills and personality factors for engineering students was low. The heterogeneous personality group had a more improvement in teamwork skills than homogeneous personality group but the effect of group difference was not statistically significant. Further, the result of this study were applied to change the design course and making the teams for improving teamwork skills for engineering students.