유 · 무인기 적용 가능한 다중센서 및 딥러닝 기반 조종사보조시스템 기술개발

최기영(Keeyoung Choi),김인중(Injoong Kim),김병성(Byungsung Kim),김종한(Jonghan Kim),이대우(Daewoo Lee),김치붕(Chibung Kim),김성수(Sungsu Kim) 항공우주시스템공학회 2018 항공우주시스템공학회 학술대회 발표집 Vol.2018 No.11

The effect of cathode felt geometries on electrochemical characteristics of sodium sulfur (NaS) cells: Planar vs. tubular

Kim, Goun,Park, Yoon-Cheol,Lee, Younki,Cho, Namung,Kim, Chang-Soo,Jung, Keeyoung Elsevier 2016 Journal of Power Sources Vol.325 No.-

<P><B>Abstract</B></P> <P>Two sodium sulfur (NaS) cells, one with a planar design and the other with a tubular design, were subject to discharge-charge cycles in order to investigate the effect of cathode felt geometries on electrochemical characteristics of NaS cells. Their discharge-charge behaviors over 200 cycles were evaluated at the operation temperature of 350 °C with the current densities of 100 mA cm<SUP>−2</SUP> for discharge and 80 mA cm<SUP>−2</SUP> for charge. The results showed that the deviation from theoretical open circuit voltage changes of a planar cell was smaller than those of a tubular cell resulting in potential specific power loss reduction during operation. In order to understand the effect, a three dimensional statistically representative matrix for a cathode felt has been generated using experimentally measured data. It turns out that the area specific fiber number density in the outer side area of a tubular cathode felt is smaller than that of a planar felt resulting in occurrence of larger voltage drops via retarded convection of cathode melts during cell operation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Tubular and planar cathode preforms were fabricated with the identical cathode felt. </LI> <LI> V changes of tubular and planar NaS cells were monitored at 350 °C for 200 cycles. </LI> <LI> Deviation from ideal OCV of a planar cell was smaller than that of a tubular cell. </LI> <LI> Smaller deviation attributes to constant fiber number density along radial direction. </LI> <LI> 3D statistically representative felt matrix was generated using experimental data. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The Relationships of Guidance Counselors' Job Performance to Personality Traits, Demographic Backgrounds, And Professional Qualifications: Implication to the Organization and Development of School Guidance and Counseling in Korea

Kim,Keeyoung 聖心女子大學校 1986 論文集 Vol.18 No.-

An innovative electronically-conducting matrix of the cathode for sodium sulfur battery

Kim, Seong In,Park, Won Il,Jung, Keeyoung,Kim, Chang-Sam Elsevier 2016 Journal of Power Sources Vol.320 No.-

<P><B>Abstract</B></P> <P>An innovative electronically-conducting cathode matrix, that makes sodium sulfur (NaS) battery excellent in discharge-charge performance, is prepared by surface modification of a carbon felt with inorganic nanoparticles. A carbon felt is dipped into an inorganic-organic hybrid sol, dried, and heat-treated at 600 °C for 2 h in a flowing argon. Coated surface of the felt has been examined by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and scanning transmission electron microscopy (STEM). The cell prepared with the coated carbon felt shows 92% of charge acceptance and 99.9% of coulombic efficiency at 100 mA cm<SUP>−2</SUP> of current density.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Carbon felt good wettable with sodium polysulfides is prepared using hybrid sol. </LI> <LI> Coated carbon felt shows little sulfur on the electrolyte at 100 mA cm<SUP>−2</SUP> on charge. </LI> <LI> Coulombic efficiency of the cell with the coated carbon felt retains above 99.9%. </LI> </UL> </P>

A thermo-mechanical stress prediction model for contemporary planar sodium sulfur (NaS) cells

Jung, Keeyoung,Colker, Jeffrey P.,Cao, Yuzhe,Kim, Goun,Park, Yoon-Cheol,Kim, Chang-Soo Elsevier 2016 Journal of Power Sources Vol.324 No.-

<P><B>Abstract</B></P> <P>We introduce a comprehensive finite-element analysis (FEA) computational model to accurately predict the thermo-mechanical stresses at heterogeneous joints and components of large-size sodium sulfur (NaS) cells during thermal cycling. Quantification of the thermo-mechanical stress is important because the accumulation of stress during cell assembly and/or operation is one of the critical issues in developing practical planar NaS cells. The computational model is developed based on relevant experimental assembly and operation conditions to predict the detailed stress field of a state-of-the-art planar NaS cell. Prior to the freeze-and-thaw thermal cycle simulation, residual stresses generated from the actual high temperature cell assembly procedures are calculated and implemented into the subsequent model. The calculation results show that large stresses are developed on the outer surface of the insulating header and the solid electrolyte, where component fracture is frequently observed in the experimental cell fabrication process. The impacts of the coefficients of thermal expansion (CTE) of glass materials and the thicknesses of cell container on the stress accumulation are also evaluated to improve the cell manufacturing procedure and to guide the material choices for enhanced thermo-mechanical stability of large-size NaS cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A comprehensive FEA model is introduced to predict stress in contemporary planar NaS cell. </LI> <LI> Model includes relevant experimental procedures for planar NaS cell assembly and operation. </LI> <LI> Large stresses were developed on the outer surface of insulating header and solid electrolyte. </LI> <LI> Cell container thickness plays an important role in the stress accumulation of planar NaS cell. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

오비디우스 『변신이야기』의 에필로그(15.871~9)에 나타난 오비디우스 변신의 의미

김기영(Kim, Keeyoung) 한국외국어대학교 외국문학연구소 2013 외국문학연구 Vol.- No.51

본고는 로마 서사시 『변신이야기』의 에필로그에 나타난 시인 오비디우스의 변신이 어떤 의미를 갖는지 규명하고자 했다. 이 연구 목적을 달성하기 위하여 필자는 우선 ??변신이야기??의 전체 구성을 관찰했다. 이 관찰을 바탕으로 작품 구성에서 중요한 위상을 차지한 두 신화, 즉 아라크네의 변신과 오르페우스의 죽음의 서사를 분석하고 작품 후반부에서 부각된 아이네아스, 로물루스, 카이사르의 신격화를 고찰했다. 이러한 연구 결과, 『변신이야기』의 두 가지 흐름이 작품의 에필로그에 수렴하고 있음을 관찰할 수 있었다. 하나의 흐름은 아라크네 변신과 오르페우스 죽음이다. 아라크네와 오르페우스는 오비디우스적 문학 양식을 구현하는 예술가이지만 이 두 예술가는 모두 권력과 폭력에 희생되고 만다. 오비디우스의 자화상에 해당 하는 두 신화는 마침내 오비디우스가 시로 변신하는 에필로그와 연동된다고 하겠다. 또 다른 하나의 흐름은 아이네아스, 로물루스, 카이사르로 이어지는 신격화이다. 이러한 신격화는 자연스럽게 아우구스투스 황제의 신격화를 기대하게 하지만, 에필로그에선 시인 오비디우스의 신격화가 등장하는 반전이 일어난다. 요컨대 이 두 가지 흐름은 시인 오비디우스의 불멸과 명성을 선언하는 에필로그에 수렴한 것이다. 따라서 변신이란 원리로 만물유전을 재현하고 여러 개별 신화들이 무질서하게 묶여져 있다고 본 『변신이야기』는 하나의 목표, 즉 권력에 대(對)한 예술의 불멸과 승리를 향한 움직임이라 하겠다. This paper aims to investigate the meaning of the poet"s metamorphosis in the epilogue of the epic Metamorphoses. To accomplish this plan, this paper, first, examines the whole structure of the work. Next, this paper analyzes not only the narrative of the two myths, i.e. Arachne"s metamorphosis and Orpheus" death, but also the narrative of the apotheosis of Heracles, Aeneas, Romulus, and Caesar, which appears successively in the progression from myth to Roman history. This analysis demonstrates that the two main storylines converge in the epilogue of the work. One storyline depicts the metamorphosis of Arachne and the death of Orpheus. In this storyline, Arachne and Orpheus both represent artists configurating the Ovidian literary style. They both fall victim to power and violence, however, which signifies Augustan ideology. The other storyline is the successive apotheosis of Heracles, Aeneas, Romulus, and Caesar. In this narrative of apotheosis we are led to expect the impending apotheosis of the emperor August in the epilogue. Contrary to our expectations, the apotheosis of the poet Ovid appears instead. Therefore, the convergence of the two storylines in the epilogue serves to proclaim the fame and immortality of the poet Ovid. This leads to the conclusion that the Metamorphoses, which appeared to represent the inorganic accumulation of many individual myths by means of the principle of metamorphosis, turns out to emphasize the immortality and victory of poetry over power and authority. 본고는 로마 서사시 『변신이야기』의 에필로그에 나타난 시인 오비디우스의 변신이 어떤 의미를 갖는지 규명하고자 했다. 이 연구 목적을 달성하기 위하여 필자는 우선 ??변신이야기??의 전체 구성을 관찰했다. 이 관찰을 바탕으로 작품 구성에서 중요한 위상을 차지한 두 신화, 즉 아라크네의 변신과 오르페우스의 죽음의 서사를 분석하고 작품 후반부에서 부각된 아이네아스, 로물루스, 카이사르의 신격화를 고찰했다. 이러한 연구 결과, 『변신이야기』의 두 가지 흐름이 작품의 에필로그에 수렴하고 있음을 관찰할 수 있었다. 하나의 흐름은 아라크네 변신과 오르페우스 죽음이다. 아라크네와 오르페우스는 오비디우스적 문학 양식을 구현하는 예술가이지만 이 두 예술가는 모두 권력과 폭력에 희생되고 만다. 오비디우스의 자화상에 해당 하는 두 신화는 마침내 오비디우스가 시로 변신하는 에필로그와 연동된다고 하겠다. 또 다른 하나의 흐름은 아이네아스, 로물루스, 카이사르로 이어지는 신격화이다. 이러한 신격화는 자연스럽게 아우구스투스 황제의 신격화를 기대하게 하지만, 에필로그에선 시인 오비디우스의 신격화가 등장하는 반전이 일어난다. 요컨대 이 두 가지 흐름은 시인 오비디우스의 불멸과 명성을 선언하는 에필로그에 수렴한 것이다. 따라서 변신이란 원리로 만물유전을 재현하고 여러 개별 신화들이 무질서하게 묶여져 있다고 본 『변신이야기』는 하나의 목표, 즉 권력에 대(對)한 예술의 불멸과 승리를 향한 움직임이라 하겠다. This paper aims to investigate the meaning of the poet"s metamorphosis in the epilogue of the epic Metamorphoses. To accomplish this plan, this paper, first, examines the whole structure of the work. Next, this paper analyzes not only the narrative of the two myths, i.e. Arachne"s metamorphosis and Orpheus" death, but also the narrative of the apotheosis of Heracles, Aeneas, Romulus, and Caesar, which appears successively in the progression from myth to Roman history. This analysis demonstrates that the two main storylines converge in the epilogue of the work. One storyline depicts the metamorphosis of Arachne and the death of Orpheus. In this storyline, Arachne and Orpheus both represent artists configurating the Ovidian literary style. They both fall victim to power and violence, however, which signifies Augustan ideology. The other storyline is the successive apotheosis of Heracles, Aeneas, Romulus, and Caesar. In this narrative of apotheosis we are led to expect the impending apotheosis of the emperor August in the epilogue. Contrary to our expectations, the apotheosis of the poet Ovid appears instead. Therefore, the convergence of the two storylines in the epilogue serves to proclaim the fame and immortality of the poet Ovid. This leads to the conclusion that the Metamorphoses, which appeared to represent the inorganic accumulation of many individual myths by means of the principle of metamorphosis, turns out to emphasize the immortality and victory of poetry over power and authority.

안드로이드 스튜디오의 GPS 와 Accelerometer 데이터를 이용한 운전 습관 분석 시스템

윤기영(KeeYoung Yoon),김규식(KyuSik Kim),김한아(HanAh Kim),성창훈(ChangHoon Sung),윤용운(YongUn Yoon) 한국정보과학회 2019 한국정보과학회 학술발표논문집 Vol.2019 No.12

자탄 분산 요구도 만족을 위한 시뮬레이션 이용 설계 기법

김길수(Kilsu Kim),최기영(Keeyoung Choi),박정호(Jeongho Park),김길훈(Kilhun Kim) 한국항공우주학회 2018 한국항공우주학회 학술발표회 논문집 Vol.2018 No.11

Microstructure and mechanical properties of Ni foam/stainless steel joint brazed using Ni-based alloy

Heo, Hoejun,Kim, Gyulin,Kim, Dae Yeon,Moon, Chanhee,Kim, Kyung Chun,Jung, Keeyoung,Kang, Chung-Yun Elsevier 2019 Materials science & engineering. properties, micro Vol.740 No.-

<P><B>Abstract</B></P> <P>An open-cell Ni foam and 304 stainless steel (SS304) were brazed using a Ni based-alloy (MBF20) as a metallic glass brazing filler by varying the brazing temperature (1030–1090 °C) and dwell time (0–60 min). Microstructures and mechanical properties of the joints were investigated to determine the best brazing conditions. When the brazing temperature was low and the dwell time was short, Ni foam was partially reacted with the filler metal in the Ni strut providing a good bonding strength. At higher bonding temperature and/or longer dwell time, a large amount of α-Ni and Ni<SUB>3</SUB>B phases were developed in the strut as B in the filler metal diffused into Ni strut. The size of Ni<SUB>3</SUB>B and its area fraction were increased with increasing temperature and time. In this stage, it was observed that cracks were readily initiated and propagated perpendicular to the tensile direction through interconnected Ni<SUB>3</SUB>B intermetallic compound resulting in degradation of fracture loads and % elongation. Based on the results, a set of acceptable dwell temperature-time couples were determined to the required bonding strength.</P>

우주안보전문가 양성을 위한 채용연계형 계약학과 교과과정 연구

김동호(Dongho Kim),황민식(Minsig Hwang),유혜은(Hyeeun Yoo),한경환(KyungHwan Han),최기영(Keeyoung Choi),노태성(Tae Seong Rho),김요섭(Yo Sup Kim) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.11