Newly Developed Technology Introduction: Radioactive Spent Resin Treatment System Using Combined Dewatering Hopper

JongSeo Choi,Sung-Hyun Heo,Yun Jae Lee,Gi-Ho Park 한국방사성폐기물학회 2018 한국방사성폐기물학회 학술논문요약집 Vol.2018 No.05

The Effects of Hairy Vetch Application on Soybean Yield and Soil Physico-chemical Properties Under Different Soil Textures

Jongseo Choi,Shingu Kang,Sukjin Kim,Jeong Hwa Park,Woonho Yang 한국토양비료학회 2018 한국토양비료학회지 Vol.51 No.4

Hairy vetch (Vicia villosa Roth) is an important green manure crop which decomposes rapidly in soil and releases significant amount of nitrogen to subsequent crops. The incorporation of hairy vetch also contributes to organic matter accumulation and improvement of soil structure. However, appropriate management techniques for soybean production using hairy vetch have not been well studied yet. This study was conducted to investigate the effect of hairy vetch on the soil physico-chemical properties and soybean yield in different soil textures. The experimental soils were classified as clay loam, loam, sandy loam and sand. Hairy vetch was incorporated into soils of different texture at three different rates before sowing of soybean. The amount of incorporated hairy vetch was calculated from the nitrogen content of the biomass which were equivalent to 50, 100, and 150% of the recommended N fertilization rate for soybean, respectively. The growth and yield of soybean in hairy vetch plots were higher than those in conventional plot in clay loam and sand, but they were similar in loam and sandy loam. Soybean yields in clay loam and sand increased along with increase of incorporated hairy vetch biomass. Addition of hairy vetch resulted in increased available P and decreased pH in all soils except loam. Hairy vetch plot showed increased soil water content at 5-10 cm depth in sand, which possibly affects the water availability to plant. In clay loam soil treated with hairy vetch, water content increased at 0-5 cm depth and decreased at 5-10 cm depth compared with conventional plot. This study shows that application of hairy vetch green manure improves soybean yield through the alteration of the soil physical property such as water holding capacity and permeability, especially in very coarse or fine-textured soils.

An Optimization Model for a Hotel-room Layout Problem in Cruise Ship Design

Jongseo Park,Minjoo Choi 대한산업공학회 2020 대한산업공학회 추계학술대회논문집 Vol.2020 No.11

Nano-film coated cathode functional layers towards high performance solid oxide fuel cells

Choi, Mingi,Lee, Jongseo,Lee, Wonyoung The Royal Society of Chemistry 2018 Journal of Materials Chemistry A Vol.6 No.25

<P>Nano-structured composite electrodes, from a carefully conducted infiltration process, are one of the most promising electrode structures for intermediate temperature solid oxide fuel cells (IT-SOFCs), due to their ability to promote the oxygen reduction reaction (ORR) and enlarge triple phase boundaries (TPBs). Here, we demonstrate rational design of infiltrated nano-structures for IT-SOFCs with enhanced ORR kinetics and excellent stability. We systematically designed a nano-structured cathode functional layer (CFL) from the infiltration of Sm0.5Sr0.5CoO3−δ (SSC) into porous Gd0.2Ce0.8O2−δ (GDC). By controlling the drying process during the infiltration process, two distinct nano-structures of SSC, discrete coating and film-like coating, were fabricated on the GDC scaffolds. The CFL with the film-like coating showed ∼30% reduction in polarization resistance (<I>R</I>p) and ∼15% increase in peak power density at 650 °C compared to the CFL with the discrete coating in spite of ∼12-fold lower loading of infiltration materials. Furthermore, the CFL with the film-like coating showed an excellent stability, maintaining an <I>R</I>p of 0.029 Ω cm<SUP>2</SUP> for 100 h at 650 °C. Our results demonstrated that the high performance and stability of composite electrodes for IT-SOFCs can be achieved through a thin-film coated CFL.</P>

Encapsulation of Metal Catalysts for Stable Solid Oxide Fuel Cell Cathodes

Jongseo Lee,Mingi Choi,이원영 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.5

Metal catalysts have been employed as cathodes for solid oxide fuel cells to facilitate the surface exchange rate in the intermediate temperature range (600–800 °C). However, incorporated metal catalysts easily agglomerate, resulting in the loss of the reaction sites; thus, the electrochemical performance rapidly deteriorates over time. To hinder the agglomeration of metal catalysts while maintaining the catalytic activity, we encapsulated metal catalysts with nano-particulated perovskite materials using an infiltration technique. The encapsulation of Ag nanoparticles with nano-particulated Sm 0.5 Sr 0.5 CoO 3-δ (SSC) successfully prevented the agglomeration of Ag nanoparticles, maintaining the initial polarization resistance for 200 h at 650 °C, while the polarization resistance of the SSC electrodes with the Ag nanoparticles increased by ~ 190% after 200 h at 650 °C because of the thermal agglomeration of Ag nanoparticles.

Solid State Transformer의 Averaged Model 개발 및 검증

나종서(Jongseo Na),김철민(Cholmin Kim),이지훈(Jeehoon Lee),최유진(Youjin Choi),김세현(Sehyun Kim),허견(Kyeon Hur) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.7

해양공간자료의 공간 단위 임의성 문제(MAUP)와 저감 방안

임종서(Jongseo Yim),최희정(Hee Jung Choi),남정호(Jungho Nam) 한국해양환경·에너지학회 2021 한국해양환경·에너지학회 학술대회논문집 Vol.2021 No.5

이 연구는 해양공간의 합리적이고 지속가능한 관리에 필요한 공간정보를 수집 및 활용하는 과정에서 발생하는 공간 단위 임의성 문제(Modifiable areal unit problem; MAUP)를 검토하고, 이에 대한 저감 방안을 모색하였다. 육상에 비해 물질과 에너지의 흐름이 원활한 해양공간은 상대적으로 넓은 공간이 동질적이며, 동시에 가변성이 높기 때문에 정보의 공간적 밀집도가 비교적 낮다. 해상풍력발전 등 해양공간 이용행위의 다변화 및 고밀화와 해양공간계획법과 이에 따른 관리제도의 도입 등으로 인해 고해상도 공간정보의 수요가 크게 증가하였다. 현행 해양공간관리제도, 의사결정지원체계 등이 적용한 각분(arc-min) 및 아(sub) 각분 단위 방형 격자는 편의성이 높지만 점용·사용 등 개별 해양공간 이용행위를 반영하기엔 어려움이 있으며, 일부 환경·생태계 조사자료는 도, 분 단위로 구성된 정점 조사체계를 통해 수집하기 때문에 격자자료로 가공한 정보를 활용하기에 앞서 공간 단위 임의성 문제를 고려할 필요가 있다. 이 연구는 공간정보의 생산 및 관리 체계에서 비롯되는 해양공간자료의 특성에 주목하여 자료 활용 시 발생할 수 있는 공간 단위 임의성 문제를 파악하고, 공간 할당(allocation), 분할(disaggregation), 보간(interpolation)에 따른 격자자료 변환 결과를 상호 비교하였다. 이후 시나리오별로 격자 위치 변경에 따른 민감도 평가 결과를 토대로 해양공간자료의 공간 단위 임의성 문제 저감 방안을 모색하였다. This study examined the Modifiable Area Unit Problem (MAUP), which occurs in collecting and utilizing maritime spatial information, and sought ways to reduce it. The spatial data in marine space, where materials and energy flux are higher than those in terrestrial area, has relatively low spatial density due to the spatial characteristics. Recently, the demand for high-resolution spatial information has increased significantly due to diversified and congested marine space utilization activities such as offshore wind power generation, and the implementation of marine spatial management policies such as the Marine Space Planning Act. Although each square lattice of arc-min and sub, applied by the current marine space management system and decision support system, is convenient, there is a limit to reflect individual marine space use activities such as occupancy and use. Moreover, some environmental and ecological survey data are collected through vertex survey system consisting of arc-degrees or arc-minutes, so it is necessary to consider the MAUP before utilizing the information processed as lattice data. This study focused on the characteristics of marine spatial data resulting from the production and management of spatial information, identifying the MAUP, and sought the ways to reduce the problem based on the sensitivity assessment result of lattice data with different conversion methods such as spatial allocation, disaggregation, and interpolation.

Analysis of forty years long changes in coastal land use and land cover of the Yellow Sea: The gains or losses in ecosystem services

Yim, Jongseo,Kwon, Bong-Oh,Nam, Jungho,Hwang, Jin Hwan,Choi, Kyungsik,Khim, Jong Seong Elsevier 2018 Environmental pollution Vol.241 No.-

<P><B>Abstract</B></P> <P>The drastic land cover change and its impacts in the Yellow Sea have long been significant issues in terms of coastal vulnerabilities, but holistic data analysis is limited. The present study first reports 40 years long geographical changes of the Yellow Sea coasts including all three neighboring countries of China, North Korea, and South Korea. We delineated tidal flats by analysis of Landsat series satellite imageries (662 scenes) between 1981 and 2016. A total area of the Yellow Sea tidal flats has been considerably reducing for the past 36 years, from ∼10,500 km<SUP>2</SUP> (1980s) to ∼6700 km<SUP>2</SUP> (2010s), say ∼1% annual loss. A majority loss of tidal flats was mainly due to the grand reclamations that conducted in almost entire coast of the Yellow Sea, particularly concentrated in the 1990s-2000s. Coastal reclaimed area during the past four decades reached ∼9700 km<SUP>2</SUP>, including ongoing and planned projects, which corresponds to over half the area of precedent natural tidal flats of the Yellow Sea. The potential carbon stocks in the eight representative regions with large scale reclamation indicated significant loss in carbon sink capacity in the South Korea's coast (∼99%), while evidenced a lesser loss from the China's coast (∼31%). It was noteworthy that the progradation of tidal flats after the reclamation in China's coast significantly reduced the loss of carbon sequestration. According to the ecosystem services valuation for the Yellow Sea, a total loss was estimated as ∼8 billion USD yr<SUP>−1</SUP> with relatively high proportional loss (up to 25%) of climate regulating services (viz., carbon sequestration). Overall, huge losses in ecosystem services being provided by the Yellow Sea natural tidal flats need immediate action to prevent or at least alleviate accelerating ecological deteriorations. Finally, future conservative policy direction on coastal wetlands management has been proposed towards enhancement of marine ecosystem services.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Tidal flats area in the Yellow Sea reduced by ∼36% from 1981 to present, say 1% annual loss. </LI> <LI> Cumulative reclaimed area along the Yellow Sea coast reached ∼9700 km<SUP>2</SUP> for past 40 years. </LI> <LI> Complete destruction of carbon stock (>99%) was evidenced by coastal reclamation in Korea. </LI> <LI> Annual loss of ESV in the entire coast of the Yellow Sea was estimated ∼8 Billion USD. </LI> <LI> This study reconfirmed the relationship between coastal development and ecological impact. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

국내 도로 환경에서의 자율주행을 위한 객체 검출 알고리즘 평가 및 검증 플랫폼 개발

이종서(Jongseo Lee),권병헌(Byeongheon Kwon),최은재(Eunjae Choi),빈죤(Vinjohn Chirakkal),신유영(Yuyeong Shin),송영기(Younggi Song) 한국자동차공학회 2020 한국자동차공학회 부문종합 학술대회 Vol.2020 No.7

최근 자율주행을 위하여 인지 센서를 이용한 객체 검출 연구가 활발히 진행되는 반면에 이를 검증할 수 있는 플랫폼이 부족하다. 국외의 공개 데이터세트(KITTI, CityScapes 등)를 이용하여 인지 알고리즘을 평가할 수 있지만, 국내의 도로 상황과 다른 부분이 있어 국내 도로환경에서 자율주행을 검증하는데 한계가 있다. 따라서 본 논문에서는 국내 도로 환경에서의 자율주행을 위한 객체 검출 알고리즘 평가 및 검증 플랫폼을 제안한다. 데이터 취득은 자율주행 차량과 동일한 센서 구성을 한 차량으로 취득하였고 다양한 use-case에 대한 데이터를 취득하였다. 평가는 2D time-to-collision(TTC)와 mean Average Precision(mAP)를 이용하여 평가한다.

데이터 마이닝과 심층 신경망을 이용한 벽면 효과 보정에 관한 기초 연구

박종서(Jongseo Bak),태명식(Myungsik Tai),박동훈(Donghun Park),최은혜(Eunhye Choi),김남균(Namgyun Kim),정신규(Shinkyu Jeong) 한국항공우주학회 2021 한국항공우주학회 학술발표회 논문집 Vol.2021 No.11