Branched DNA-based Synthesis of Fluorescent Silver Nanocluster

Park, Juwon,Song, Jaejung,Park, Joonhyuck,Park, Nokyoung,Kim, Sungjee Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

While single strand DNAs have been widely used for the scaffold of brightly fluorescent silver nanoclusters (Ag NCs), double strand DNAs have not been as successful. Herein, we report a novel synthetic approach for bright Ag NCs using branched double strand DNAs as the scaffolds for synthesis. X-shaped DNA (X-DNA) and Y-shaped DNA (Y-DNA) effectively stabilized Ag NCs, and both X-DNA and Y-DNA resulted in brightly fluorescent Ag NCs. The concentration and molar ratio of silver and DNA were found important for the fluorescence efficiency. The brightest Ag NC with the photoluminescence quantum efficiency of 19.8% was obtained for the reaction condition of 10 ${\mu}M$ X-DNA, 70 ${\mu}M$ silver, and the reaction time of 48 h. The fluorescence lifetime was about 2 ns for the Ag NCs and was also slightly dependent on the synthetic condition. Addition of Cu ions at the Ag NC preparations resulted in the quenching of Ag NC fluorescence, which was different to the brightening cases of single strand DNA stabilized Ag NCs.

ANALYSIS OF BODY MEASUREMENT ERROR ABOUT 3D SCAN DATA FOR ELDERLY

Jinhee Park,Juwon Chung,Yu Hwa Hong,Yun Ja Nam 글로벌지식마케팅경영학회 2015 Global Fashion Management Conference Vol.2015 No.06

Measuring body size with a 3D scanner can reduce inter-measurer variability and provide better accuracy compared to using a traditional methods of measurement (Park, Nam, & Park, 2009). Many size measurement projects (or studies) that measure body size established a size measurement method prior to the development of a 3D scanner and automatic size measurement programs that produce 3D virtual body size measurements (Park, &Nam, 2012). Size data measured through an automatic size measurement program are more accurate and have a lower variability that is more appropriate for body measurements (Han, & Nam, 2004; Nam, Choi, Jung, & Yun, 2004). However, this method is limited to healthy subjects who can maintain a correct posture in a 3D scanner. It is difficult for the elderly to maintain the correct posture for body measurements in ‘Basic Human Body Measurements for Technological Design’ of ISO 7250(1997). Body measurement definitions are based on vertical and horizontal directions consequently, it is hard to measure those with a bent body type even if they stand in a correct posture. Most body measurement items are automatically measured in vertical and horizontal directions because current automatic size measurement programs utilize algorithms based on typical body measurement definitions. The size measurement method based on a vertical and horizontal directions tends to have a problem for elderly individuals with a bent body type who have difficulty maintaining a correct posture for 3D scanning as defined in ISO 7250(1997)(Ashdown, & Na, 2008).This study analyzes the problem of present auto-measurement programs that use elderly’s 3D body scan data. We conducted a comparative analysis of elderly’s body sizes using an auto-measurement program from virtual 3D body scan data and direct measurement with traditional measurement methods. We establish 34 typical body size measurements for the use of data from 464 males and 472 females (total 936) between the ages of 70 to 85. For error analysis, data separated to normal values and outliers compared with ISO 20655(2003). ISO 20685 defines the accuracy of extracted measurements by classification and measurement type (segment lengths, body height/breaths/depth, large/small circumferences, and head/hand/foot dimensions). The majority of outliers for the male and female body height type was “height”. Total number of persons with outliers for Height’s data was 603; consequently, 64.4% of subjects (elderly group of 70-85 yrs.) could not maintain a correct posture when scanning. Other data also had many errors from inaccurate measurement postures. A total of 72.3% of males and 70% of females have incorrect values in small circumferences. The segment lengths’ error data was 76.5% of males and 75% of females; in addition, the head dimension’ outliers were 87% for both male and female subjects. Especially 57.46% of males had incorrect data, while 74.67% of females had a type of large circumference. Female chest circumference had significant errors due to sagging breasts. The differences identify with a correlation between type of large circumference (chest, hip, under bust, waist, waist of omphalion) and gender. There were several correlations between the many measurement errors because values over 70% of data have outliers; however, each measurement type has properties in regards to correlation. A substantial positive correlation was found between all measurements (except hip circumference) in the type of large circumference; in addition, one-way ANOVA indicated that the measurements influenced height and were statistically significant. Outliers found in height data for the elderly’s were more likely to have errors in the type of large circumference. The type of body height indicated a strong correlation and statistical significance between the axilla height and other measurements (height, waist, crotch, lateral malleolus). Axilla height with more outliers indicated that other type of body height measurements had a higher potential for errors. The posture for body measurement was standardized as standing erect; however, this study indicated that many measurement errors were possible between using an auto-measurement program and direct measurement. The value of outlier about a particular measurement item can expect increased errors about any group (height: large circumference group/ axilla height: body height group). We have to study the relation in measurements in these types ‘large circumference’ because ‘head dimensions’ types correlate between measurements in each group. We need a more detailed analysis about outliers to find the major factors for measurement errors in regards to the elderly as well as discuss the possibility of ISO measurement-standard’s application for the elderly.

Optical Properties and Field Emission of ZnO Nanorods Grown on p-Type Porous Si

Park, Taehee,Park, Eunkyung,Ahn, Juwon,Lee, Jungwoo,Lee, Jongtaek,Lee, Sang-Hwa,Kim, Jae-Yong,Yi, Whikun Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

N-type ZnO nanorods were grown on p-type porous silicon using a chemical bath deposition (CBD) method (p-n diode). The structure and geometry of the device were examined by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) while the optoelectronic properties were investigated by UV/Vis absorption spectrometry as well as photoluminescence and electroluminescence measurements. The field emission (FE) properties of the device were also measured and its turn-on field and current at 6 $V/{\mu}m$ were determined. In principle, the growth of ZnO nanorods on porous siicon for optoelectronic applications is possible.

Heterojunction Area-Controlled Inorganic Nanocrystal Solar Cells Fabricated Using Supra-Quantum Dots

Park, Juwon,Hwang, Sungjae,Jeong, Sanghwa,Kim, Sungjee,Bang, Jiwon,Cho, Seungho American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.50

<P>A supra-quantum dot (SQD) is a three-dimensional structure formed by the attachment of quantum dots. The SQDs have sizes of tens of nanometer and they maintain the characteristics of the individual quantum dots fairly well. Moreover, their sizes and elemental compositions can be tuned precisely. On the basis of their unique features, in this work, SQDs are used as constituents of the interpenetrating photoactive layers of inorganic nanocrystal p-n heterojunction solar cells to control the p-type and n-type domain sizes (i.e., p-n heterojunction areas) for optimizing the charge-carrier collection. SQD-containing p-n heterojunction solar cells exhibit improved charge transport and thereby higher power conversion efficiency (PCE) (3.03%) owing to their intermediate p-type and n-type domain sizes, which are between those of a bilayer nanorod p-n heterojunction solar cell (PCE: 1.21%) and an interpenetrating nanorod p-n heterojunction solar cell (PCE: 2.40%). This work demonstrates that the self-assembly of nanoscale materials can be utilized for tailoring the spatial distributions of charge carriers, which is beneficial for obtaining an enhanced device performance.</P> [FIG OMISSION]</BR>

A Study on the Transition Strategy of Military Service in Korea Using PEST-SWOT-FUZZY-AHP

Juwon Park(박주원),Wonseok Kang(강원석) 이화여자대학교 경영연구소 2021 신산업경영저널 Vol.39 No.1

최근 병역 면제와 대법원의 양심적 병역거부자에 대한 무죄 선고는 군 복무의 부당성에 대한 대중의 인식을 높였고 군 제도의 변화에 대한 정치인들의 논쟁을 가속화시켰다. 특히 첨단 기술 군으로의 양상전환 및 출산율 감소로 인한 인구 감소도 병역제도의 변화를 요구하고 있다. 병역제도 개편은 현재 국내에서 유지되고 있는 징병제에서 지원자를 직업군인으로 모집해 군을 유지하는 모병제도를 말한다. 이러한 배경에서 이 연구는 PEST-SWOT-FUZZ-AHP 분석에 기초해 현재의 군복무 전환 전략의 도입에서 발생하는 질적 한계를 극복하기 위해 의사결정자의 대응 신뢰도를 반영하는 정량적 방법론을 사용했으며, 전략적인 도구로서 SWOT 요소별 중요도와 그에 따른 전략을 제시하였다. 분석 결과 강점 요인에서는 ‘병력 구조 개편 및 감축 가속화’, 약점에서는 ‘병역 자원 확보의 어려움’이 가장 중요한 요인으로 나타났으며 기회요인에서는 ‘국민의 지지증가’가 가장 중요한 요인으로 도출 되었고 마지막으로 위협 요인에서는 ‘예산 확보의 어려움’이 가장 중요한 요인으로 도출되었다. 이를 바탕으로 SO, WO, WT, ST전략의 상대적 중요도와 각각에 맞는 전략을 제시하였으며 SO전략은 병력 구조개편을 통해 전문성을 확보하고 이를 바탕으로 국민의 지지를 얻는 전략, WO전략은 군 내부마케팅을 바탕으로 공감대를 형성하고 병역 자원을 확보하고 국민의 지지를 얻기 위한 공보 전략, ST전략은 군의 전문화, 첨단화에 필요한 예산을 우선적으로 확보하는 전략, WT전략은 병역 자원 확보를 위한 군인의 직업적 혜택을 증가하는 예산을 우선적으로 확보하는 전략이 도출되었다. 이는 단기적으로 한국의 상황에 맞는 동태적 SWOT전략으로 WT전략-WO전략-SO전략을 제시한 것이며, 병역제도의 변화에 대응하는 전략을 개발하기 위한 정량적 방법의 사용을 보여주었다. The recent military service exemption and the Supreme Courts acquittal of conscientious objectors increased public awareness of the unfairness of the military service and accelerated the debate among politicians about a change in the military system. Particularly, the population decline due to the decreasing birth rate and a transition to high-tech military warfare are also calling for a change in the military service system. The change in the military service system refers to a change from the current conscription system maintained in Korea to the recruitment system, which is a system that forces the people to serve in the military, and the recruitment system refers to a system that maintains the military by recruiting applicants as professional soldiers. Against this backdrop, based on the PEST-SWOT-FUZZY-AHP analysis, this study used quantitative methodologies reflecting the response reliability of decision makers to overcome qualitative limitations emerging from the introduction of the current military service transition strategy. The study also aims to present the importance of each SWOT element as a strategic tool. The analysis revealed “the reinforcement of military structure and accelerating troop reduction”, “difficulty in securing military resources,” “an increase in public support,” and “difficulty in securing a budget” as most important strength, weakness, opportunity, and threat, respectively. The results lead to the following strategies: reinforcing military structure; drawing public support; building consensus based on internal military marketing; and securing budget for enhancing specialization, providing state-of-the-art military service, and procuring military resources This shows that the dynamic WT-WO-SO (SWOT) strategies can contribute toward the current positive scenario in Korea in the short-term. The study shows the use of quantitative methods for developing strategies in response to the change in the military service system.

Microstructural design of high nickel cathode toward outstanding capacity and stability using trace element doping for lithium-ion battery application

Juwon Park(박주원),Won Myung Choi(최원명),Hiram Kwak(곽희람),Yoon Seok Jung(정윤석),Byungchan Han(한병찬) 한국표면공학회 2022 한국표면공학회 학술발표회 초록집 Vol.2022 No.6

소형발사체 상단 액체엔진 종류에 따른 임무설계 비교연구

박주원(Juwon Park),심주현(Juhyen Sim),홍용기(Yonggi Hong),손택준(Taekjoon Son),정진택(Jintaeg Jung) 한국추진공학회 2022 한국추진공학회 학술대회논문집 Vol.2022 No.5

본 논문에서는 무게 500 kg 급 위성을 고도 500 km의 태양동기궤도(SSO)에 투입할 수 있는 소형발사체 임무설계를 수행하였다. 발사체는 한국형발사체(누리호)의 2단 엔진(75 ton)을 1단으로 사용하고 2단은 임무 목표를 달성할 수 있도록 3 ton급 액체엔진을 선정하였다. 새로운 2단 엔진 선정을 위해 추진제와 엔진 사이클의 장단점을 각각 분석하고 추진제와 엔진 사이클 간 최적의 조합을 찾아 최종 두 종류의 엔진을 선정하였다. 또한 선정된 두 종류의 엔진에 따른 소형발사체의 Staging 및 임무설계를 수행하였다. 끝으로 설계된 임무가 현실적으로 타당한지 확인하기 위해 발사체 임무설계 및 분석 프로그램인 ASTOS를 사용하여 그 타당성을 확인 및 비교분석하였다. This paper carried out a mission design of a small launch vehicle that can put a 500 kg satellite into a sun-synchronous orbit(SSO) at an altitude of 500 km. The launch vehicle uses the Korea space launch vehicle(Nuri) second stage engine(75 ton class) in first stage, and a 3 ton class liquid rocket engine in second stage to achieve mission goals. During the new second stage engine selection process, the pros and cons of the each propellants and the engine cycles were analyzed and two types of engine were finally selected. Also, the staging and mission design was carried out according to the selected two types of engines. Finally, the results were verified and compared using ASTOS, a launch vehicle mission design and analysis program, to ensure that the mission design were realistically valid.

가우시안 프로세스 동적 모델링과 심층 변분 베이즈 필터링을 위한 표현형 생성모델 활용 탐구

이주원(Juwon Lee),김태환(Taehwan Kim),박정호(Jeongho Park),남상우(Sangwoo Nam),최창균(Changkyun Choi),박주영(Jooyoung Park) 한국통신학회 2020 한국통신학회 학술대회논문집 Vol.2020 No.2

N₂O 저감 연소기술 개발을 위한 이론적 분석 및 실험적 검증

박주원(Juwon Park),윤성환(Sung Hwan Yoon) 한국연소학회 2022 KOSCOSYMPOSIUM논문집 Vol.2022 No.5

리튬이온 배터리의 열폭주 메커니즘에 관한 실험적 고찰

박주원(Juwon Park),유승우(Seung Woo Yoo),박대근(Daegeun Park),윤성환(Sung Hwan Yoon) 한국연소학회 2023 KOSCOSYMPOSIUM논문집 Vol.2023 No.5