The Phase Transition and Thermochromic Characteristics of W/Mg-codoped Monoclinic VO₂ Nanoparticle and Its Composite Film

Park, Heesun,Kim, Jongmin,Jung, Young Hee,Kim, Yeong Il Korean Chemical Society 2017 대한화학회지 Vol.61 No.2

Monoclinic $VO_2(M)$ nanoparticles codoped with 1.5 at. % W and 2.9 at. % Mg were synthesized by the hydrothermal treatment and post-thermal transformation method of $V_2O_5-H_2C_2O_4-H_2O$ with $Na_2WO_4$ and $Mg(NO_3)_2$. The composite thin film of the W/Mg-codoped $VO_2(M)$ with a commercial acrylic block copolymer was also prepared on PET substrate by wet-coating method. The reversible phase transition characteristics of the codoped $VO_2(M)$ nanoparticles and the composite film were investigated from DSC, resistivity and Vis-NIR transmittance measurements compared with the undoped and Wdoped $VO_2(M)$ samples. Mg-codoping into W-doped $VO_2(M)$ nanoparticles synergistically enhanced the transition characteristics by increasing the sharpness of transition while the transition temperature ($T_c$) lowered by W-doping was maintained. The codoped composite film showed the prominently enhanced NIR switching efficiency compared to only W-doped $VO_2(M)$ film with a lowered $T_c$.

Test of Nutritional Content and Functionality between Green and Red Systems of Asian bittercress (Cardamine komarovii Nakai)

Heesun Noh,Eungeong Jeong,Jeongshin Shin,Minjeong Kim,Seokjun Hwang,Kiduk Park,Areum Park,Heeun Kim,Sichang Kim,Munseob Ahn 한국식품영양과학회 2018 한국식품영양과학회 학술대회발표집 Vol.2018 No.10

Engineered Fusion Protein with Improved Stability for Antibody Purification

Heesun PARK,Jonghwan LEE,soohyeon JEONG,Kyuhyuk IM,Sunghyun KIM 한국생물공학회 2023 한국생물공학회 학술대회 Vol.2023 No.4

Affinity Precipitation-Based Antibody Purification Using the Ca<SUP>2+</SUP>-Dependent Phase-Transition

Heesun PARK,Jonghwan LEE,Soohyeon JEONG,Jinho BANG,Sunghyun KIM 한국생물공학회 2022 한국생물공학회 학술대회 Vol.2022 No.9

Noncontrast Myocardial T1 Mapping by Cardiac Magnetic Resonance Predicts Outcome in Patients With Aortic Stenosis

Lee, Heesun,Park, Jun-Bean,Yoon, Yeonyee E.,Park, Eun-Ah,Kim, Hyung-Kwan,Lee, Whal,Kim, Yong-Jin,Cho, Goo-Yeong,Sohn, Dae-Won,Greiser, Andreas,Lee, Seung-Pyo Elsevier Science B.V. Amsterdam 2018 JACC CARDIOVASCULAR IMAGING Vol.11 No.7

<P><B>Abstract</B></P> <P><B>Objectives</B></P> <P>The aim of this study was to evaluate whether native T1 value of the myocardium on cardiac magnetic resonance (CMR) could predict clinical events in patients with significant aortic stenosis (AS).</P> <P><B>Background</B></P> <P>Although previous studies have demonstrated the prognostic value of focal fibrosis using late gadolinium enhancement (LGE) by CMR in AS patients, the prognostic implication of diffuse myocardial fibrosis by noninvasive imaging remains unknown.</P> <P><B>Methods</B></P> <P>A prospective observational longitudinal study was performed in 127 consecutive patients with moderate or severe AS (68.8 ± 9.2 years of age, 49.6% male) and 33 age- and sex-matched controls who underwent 3-T CMR. The degree of diffuse myocardial fibrosis was assessed by noncontrast mapping of T1 relaxation time using modified Look-Locker inversion-recovery sequence, and the presence and extent of LGE were also evaluated. The AS patients were divided into 3 groups by the native T1 value. Primary endpoint was a composite of all-cause death and hospitalization for heart failure.</P> <P><B>Results</B></P> <P>Native T1 value was higher in AS patients, compared with control subjects (1,232 ± 53 ms vs. 1,185 ± 37 ms; p = 0.008). During follow-up (median 27.9 months), there were 24 clinical events including 9 deaths (6 pre-operative and 3 post-operative), the majority of which occurred in the patients in the highest T1 tertile group (2.4% vs. 11.6% vs. 42.9% for lowest, mid-, and highest tertile groups; p < 0.001 by log-rank test). The total number of events for both pre- and post-operative events also occurred more frequently in patients in the highest T1 tertile group. EuroSCORE II, the presence and/or extent of LGE, and the native T1 value were predictors of poor prognosis (adjusted hazard ratio for every 20-ms increase of native T1: 1.28; p = 0.003). In particular, the highest native T1 value provided further risk stratification regardless of the presence of LGE.</P> <P><B>Conclusions</B></P> <P>High native T1 value on noncontrast T1 mapping CMR is a novel, independent predictor of adverse outcome in patients with significant AS.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Development and Test of a Cooling System for a 154 kV Superconducting Fault Current Limiter

Kim, Heesun,Han, Young Hee,Yang, Seong-Eun,Yu, Seung-Duck,Park, Byung Jun,Park, Kijun,Yoo, Jaeun,Kim, Hye-Rim,In, Sehwan,Hong, Yong Joo,Yeom, Hankil Korea Electric Power Corporation 2015 KEPCO Journal on electric power and energy Vol.1 No.1

The superconducting fault current limiter (SFCL) is an electric power device that limits the fault current immediately in a power grid. Korea Electric Power Corporation (KEPCO) has been developing a 154 kV, 2 kA SFCL since 2011 to protect power grids from increasing fault current and improve the stability and quality of electric power. This SFCL adopts 2G YBCO wires and operates at 71 K and 5 bars. In this paper, a cooling system for the 154 kV SFCL and its cooling test results are reported. This cooling system uses a Stirling-type cooler to make sub-cooled liquid nitrogen ($LN_2$), which cools the superconductor modules of the SFCL. The $LN_2$ is circulated between the cooler and the cryostat that contains superconductor modules. The $LN_2$ also plays the role of a high voltage insulator between the modules and the cryostat, so the pressure was maintained at 5 bars for high insulation performance. After installation in a test site, the cooling characteristics of the system were tested. In this operation test, some important data were measured such as temperature distribution in $LN_2$, pressure change, performance of the heat exchanger, and cooling capacity of the total system. Consequently, the results indicate that the cooling system operates well as designed.

강원도 스마트팜 농업데이터 수집 및 데이터 기반 농가 컨설팅 현황

노희선(Heesun Noh),안용진(Yonjin An),박천규(Cheongyoo Park),신동호(Tongho Shin),정정수(Jeongsu Jung),김희진(Heejin Kim),박정호(Jeongho Park),박장순(Gangsoon Park),백원기(Wonki Baek) 한국원예학회 2020 한국원예학회 학술발표요지 Vol.2020 No.11

시선 응시 점 기반의 관심영역 확장을 통한 원 거리 얼굴 검출

박희선(Heesun Park),홍장표(Jangpyo Hong),김상열(Sangyeol Kim),장영민(Young-Min Jang),김철수(Cheol-Su Kim),이민호(Minho Lee) 대한전자공학회 2012 전자공학회논문지 Vol.49 No.9

영상처리 기법을 이용한 얼굴검출에 관한 많은 다양한 방법들이 제시되어 왔다. 일반적으로 가장 많이 쓰이는 얼굴 검출 방식은 Viola와 Jones이 제안한 Adaboost 방식이다. 이 방식은 Haar-like feature을 이용하여 얼굴영상을 선행 학습하고, 검출 성능은 학습된 DB에 의존한다. 이는 일정 거리 범위 안의 학습된 얼굴 크기에서는 얼굴 검출을 잘 수행하지만, 카메라에서 객체(얼굴)의 거리가 멀어지면 얼굴 크기가 작아져 기존에 학습한 Haar-like feature로 얼굴 검출을 하지 못하는 경우가 발생한다. 이에 본 논문에서는 생물학 기반의 선택적 주의집중 기반의 Haar-like feature 정보를 이용한 Adaboost 모델과 사용자의 시선 응시 점 정보를 이용하여, 사용자의 관심영역 확장을 통한 원거리 얼굴 검출 모델을 제안한다. 생물학적 기반의 선택적 주의 집중 모델인 돌출맵(Saliency map) 정보를 이용하여 입력 영상에 대하여 얼굴 후보 영역을 검출하고, 검출된 얼굴 후보 영역 중에서 선행 학습된 Haar-like feature 정보로 Adaboost 알고리즘을 이용하여 최종 얼굴 영상을 검출한다. 그리고 사용자의 시선 응시 점 정보는 관심영역을 선택 하는데 이용된다. 피 실험자가, 카메라로부터 멀리 거리 떨어져 얼굴의 크기가 얼굴검출이 힘들더라도 사용자 시선 응시 점 영역을 선형 보간법으로 확대하여 입력영상으로 재사용함으로써 얼굴 검출 성능을 높일수 있다. 제안된 방법이 기존의 Adaboost 방법보다 얼굴 검출 성능과 수행시간 면에서 우수함을 실험을 통해 확인하였다. Face detection methods using image processing have been proposed in many different ways. Generally, the most widely used method for face detection is an Adaboost that is proposed by Viola and Jones. This method uses Haar-like feature for image learning, and the detection performance depends on the learned images. It is well performed to detect face images within a certain distance range, but if the image is far away from the camera, face images become so small that may not detect them with the pre-learned Haar-like feature of the face image. In this paper, we propose the far distance face detection method that combine the Aadaboost of Viola-Jones with a saliency map and user"s attention information. Saliency Map is used to select the candidate face images in the input image, face images are finally detected among the candidated regions using the Adaboost with Haar-like feature learned in advance. And the user’s eye-tracking information is used to select the interest regions. When a subject is so far away from the camera that it is difficult to detect the face image, we expand the small eye gaze spot region using linear interpolation method and reuse that as input image and can increase the face image detection performance. We confirmed the proposed model has better results than the conventional Adaboost in terms of face image detection performance and computational time.

외부혼합형 이류체 노즐 설계형상에 따른 미립화 성능 분석

권희선 ( Heesun Kwon ),박준규 ( Junkyu Park ),박성욱 ( Sungwook Park ) 한국액체미립화학회 2018 한국액체미립화학회 학술강연회 논문집 Vol.2018 No.-

Twin-fluid nozzles are used and applied throughout various fields of industry. In this research, an externalmixing type twin-fluid nozzle was used with water and air as working fluids. Design parameters such as nozzle diameter, exit angle, distance between the exits and the use of swirl blades were varied to assess the effect on both macroscopic and microscopic spray behaviors. Spray visualization experiments were conducted to measure the spray angle and observe the liquid column while the phase Doppler particle analyzer (PDPA) was used to calculate the droplet diameter and evaluate the droplet distribution. The nozzle diameter substantially improved the SMD, but distinct difference in macroscopic spray characteristics were not achieved. Overall, the optimization of each spray characteristics can be expected through this parametric study.

주일학교 공과 분석에 따른 교회 내 환경교육 실태 조사

박희선 ( Heesun Park ) 밴쿠버기독교세계관대학원 2021 통합연구 Vol.23 No.1

인류는 자연 파괴와 각종 환경오염으로 인한 급격한 기후변화와 천재지변, 질병 등으로 고통 받으면서 지속가능한 지구 환경 유지를 위해 목소리를 높이고 있다. 사회 각 층에서는 환경 보존을 위한 자구책을 마련하며 생활 속 환경교육의 필요성과 중요성을 크게 인식하게 되었다. 2020년 시도별 교육감들은 학교 내 환경교육 강화를 선포하고 환경부에서는 국가 수준의 교육과정에서 학생들에게 이루어지고 있는 환경교육을 파악하고 차기 교육과정에 환경교육의 방향성을 제시하였다. 그러나 교회에서는 기독 학생들을 위한 기독교적 관점의 환경교육에 관심을 두지 못하고 학교 교육에 기독교 환경교육을 맡기고 있는 것이 현실이다. 본 연구는 목적은 교회 내에서 주일학교 학생들에게 이루어지고 있는 환경교육의 실태를 파악하고, 환경교육의 필수적인 요소들이 균형 있게 포함된 기독교 환경교육의 방향을 제시하고자 한다. 연구 대상으로 현재 교단별 초등학교 공과를 선정하였으며 분석틀은 현국가수준 교육과정을 분석한 2020년 환경교육 내용 분석틀(이선경 외 6명)을 활용하였다. 연구문제는 첫째, 교단별 주일학교 공과교재에 환경교육 요소들을 어느 정도 반영하고 있으며 균형 있는 환경교육이 이루어지고 있는가? 둘째, 교단별 공과교재에 나타난 환경교육의 내용과 활동은 무엇인가? 이며 마지막으로 교회학교 공과교재 분석을 통해 교회학교 환경교육에 주는 시사점은 무엇인지 찾고자한다. The superintendents of educational districts in Korea declared the strengthening of environmental education in schools, and the Ministry of Environment in Korean government identified environmental education for students in national level courses and suggested the direction of environmental education in the next revision of curriculum. However, the reality is that the church is not interested in Christian environmental education for students and entrusts Christian environmental education to public school education. The purpose of this study is to understand the status of environmental education for Christian students in the Korean church and to provide a direction for Christian environmental education, which includes the essential elements of environmental education in a balanced method. As the subject of the study, the author selected elementary Sunday school material of some denominations and analyzed them by the frame used in the “2020 environmental education content analysis frame (Lee, Sun-kyung and 6 others), which analyzed the current national-level curriculum. The research question is: First, to what extent are the elements of environmental education reflected in the teaching materials of Sunday school denominationally, and is there a balanced environmental education? Second, what are the contents and activities of environmental education in the Sunday school materials denominationally? Lastly, through the analysis of the teaching materials for Sunday schools, I would like to find out what implications are given to environmental education in Sunday schools.