사용성평가 설계를 위한 가상현실 기술의 탐색적 연구

이명준(Myeongjun Lee),조상우(Sangwoo Cho),김신균(Shin Gyun Kim),서승우(Seung Woo Seo),이재호(Jaeho Lee),이종하(Jong-Ha Lee) 한국HCI학회 2020 한국HCI학회 학술대회 Vol.2020 No.2

기존의 사용성평가 방법은 제품의 개발단계 및 최종 단계에서 형성평가와 총괄평가를 통하여 사용대상자들이 제품의 사용하기에 제품이 효율적으로 설계 및 사용자들의 주관적 만족도를 조사하는 방법이었다. 사용성평가는 단순히 제품의 사용에 대하여 사용방법에 대하여 사용성이 높은 점을 판단할 뿐만 아니라 다양한 환경에서 제품의 사용성평가를 진행하여야 한다. 제품마다 활용환경은 다양한 것에 맞춰 매번 일상생활 환경에서 사용성평가를 설계하는 것에는 현실적으로 한계가 있다. 따라서, 영상 그래픽 이미지에서 몰입감을 느끼게 해줄 수 있는 가상현실 기술이 사용성평가에 활용되어 제품에 대한 다양한 환경을 제시할 수 있는 장점을 가진다. 본 연구에서는 사용성평가 설계 시 가상현실 기술을 적용하기 위한 주안점에 대해 탐색하였다.

Reliability and validity of the workplace harassment questionnaire for Korean finance and service workers

Myeongjun Lee,Hyunjung Kim,Donghee Shin,Sangyun Lee 대한직업환경의학회 2016 대한직업환경의학회지 Vol.28 No.-

Background: Harassment means systemic and repeated unethical acts. Research on workplace harassment have been conducted widely and the NAQ-R has been widely used for the researches. But this tool, however the limitations in revealing differended in sub-factors depending on the culture and in reflecting that unique characteristics of the Koren society. So, The workplace harassment questionnaire for Korean finace and service workers has been developed to assess the level of personal harassment at work. This study aims to develop a tool to assess the level of personal harassment at work and to test its validity and reliability while examining specific characteristics of workplace harassment against finance and service workers in Korea. Methods: The framework of survey was established based on literature review, focused-group interview for the Korean finance and service workers. To verify its reliability, Cronbach’s alpha coefficient was calculated; and to verify its validity, items and factors of the tool were analyzed. The correlation matrix analysis was examined to verify the tool’s convergent validity and discriminant validity. Structural validity was verified by checking statistical significance in relation to the BDI-K. Results: Cronbach’s alpha coefficient of this survey was 0.93, which indicates a quite high level of reliability. To verify the appropriateness of this survey tool, its construct validity was examined through factor analysis. As a result of the factor analysis, 3 factors were extracted, explaining 56.5 % of the total variance. The loading values and communalities of the 20 items were 0.85 to 0.48 and 0.71 to 0.46. The convergent validity and discriminant validity were analyzed and rate of item discriminant validity was 100 %. Finally, for the concurrent validity, We examined the relationship between the WHI-KFSW and pschosocial stress by examining the correlation with the BDI-K. The results of chi-square test and multiple logistic analysis indicated that the correlation with the BDI-K was satatisctically significant. Conclusion: Workplace harassment in actual workplaces were investigated based on interviews, and the statistical analysis contributed to systematizing the types of actual workplace harassment. By statistical method, we developed the questionare, 20 items of 3 categories.

빠른 주차를 위한 위치 파악용 카메라가 내장된 카 스토퍼의 개발

강명준(Myeongjun Kang),이상준(Sangjun Lee),이가연(Ga-Yeon Lee),이현서(Hyun-Seo Lee),김가영(Ga-Young Kim) 한국정보기술학회 2023 Proceedings of KIIT Conference Vol.2023 No.11

그림자를 이용한 캔위성 방향 측정

이주형(Juhyung Lee),한철순(Cheolsoon Han),김명준(Myeongjun Kim),이호선(Hosun Lee) 한국항공우주학회 2023 한국항공우주학회 학술발표회 논문집 Vol.2023 No.11

환경시설물 침수피해예측과 영향평가기술 개발

이창희(Changhee Lee),이재영(Jaeyoung Lee),남명준(Myeongjun Nam),노재덕(Jaedeok Roh) 대한환경공학회 2021 대한환경공학회 학술발표논문집 Vol.2021 No.11

백두대간 마루금 선자령순환등산로의 숲길훼손실태 연구

이수광 ( Sugwang Lee ),이진규 ( Jinkyu Lee ),김명준 ( Myeongjun Kim ),방홍석 ( Hongseok Bang ) 한국산림과학회(구 한국임학회) 2021 한국산림과학회지 Vol.110 No.1

본 연구는 백두대간 마루금 선자령순환등산로 4.3 ㎞에서 정성적으로 평가되는 훼손등급을 적용하여 숲길훼손이 발생된 구역의 구체적인 데이터와 조사방법을 제시하고, 조사항목간의 관계를 구명하고자 수행되었다. 그 결과, 선자령순환등산로의 평균 노폭(1.7 m)과 나지폭(1.4 m)은 지금까지 보고된 연구에 비해 매우 넓은 것으로 나타났으며, 훼손비율 또한 높은 것으로 확인되었다. 정성적인 기준으로 평가된 훼손등급에 대해 다음과 같이 구체적인 데이터를 확보할 수 있었다. 훼손등급 강의 경사도는 20.1%, 침식깊이는 평균 13.3 ㎝, 중앙 16.1 ㎝, 침식량 16.2 ㎠로 나타났으며 토양경도는 평균 12.3 ㎏/㎠(20.1 ㎜), 최대 39.3 ㎏/㎠(29.6 ㎜)로 나타났다. 훼손등급과 경사도는 양의 상관관계를 보였고, 능선보다 산복에서 평균과 중앙의 토양침식깊이가 깊어지는 것으로 나타났다. 그리고 토양경도는 횡단 측정위치와 방법에서 유의적인 차이가 있는 것으로 나타났다. 따라서 선자령순환등산로는 경사도가 20% 이상인 구간에서 훼손이 발생함에 따라 지속 가능한 이용을 위해서는 고정조사점에서의 지속적인 모니터링이 필요하다. 또한, 숲길설계와 관리에는 경사도가 우선적으로 고려되어야 한다. We conducted a study to identify the relationships between the investigated factors and provide a methodology and generate data by applying deterioration classes to the Seonjaryeong Forest Trail (4.3 ㎞) in the Baekdudaegan Ridge. The average trail width (1.7 m) and bare width (1.4 m) were wider than those obtained in the previous studies. The frequency of trail deterioration was also high. Specific data on deterioration classes were obtained and evaluated using qualitative criteria. Specific data for heavy class stands at 20.1% in trail grade, 13.3 cm on average, and 16.1 cm in the center of erosion depth, 16.2 cm of CSA, 12.3 kg/cm (20.1 ㎜) on average and maximum 39.3 kg/cm (29.6 ㎜) of soil hardness. We observed a positive correlation between the deterioration class and trail grade, and the average and maximum soil erosion depths of the hill side were deeper than those of the ridge. The soil hardness data showed a statistically significant difference in terms of the transect site and calculation method (㎏/㎠, ㎜). Therefore, trail deterioration was observed at the sites having ≥20% trail grade; thus, continuous monitoring at fixed sites over time will be required for sustainability. Furthermore, the trail grade should be of the utmost priority in trail design and management.

Structural, electro-magnetic, and optical properties of Ba(Fe,Ni)₂As₂ single-crystal thin film

Yoon, Sejun,Seo, Yu-Seong,Lee, Seokbae,Weiss, Jeremy D,Jiang, Jianyi,Oh, MyeongJun,Lee, Jongmin,Seo, Sehun,Jo, Youn Jung,Hellstrom, Eric E,Hwang, Jungseek,Lee, Sanghan IOP 2017 Superconductor science & technology Vol.30 No.3

<P>We investigated the superconducting transition temperature (<I>T</I> <SUB>c</SUB>), critical current density (<I>J</I> <SUB>c</SUB>) and optical properties of optimally doped Ba(Fe<SUB>0.95</SUB>Ni<SUB>0.05</SUB>)<SUB>2</SUB>As<SUB>2</SUB> (Ni-Ba122) single-crystalline epitaxial thin films grown by pulsed laser deposition for the first time. The <I>T</I> <SUB>c</SUB> at zero resistivity was about 20.5 K and the <I>J</I> <SUB>c</SUB> at self-field and 4.2 K was 2.8 MA cm<SUP>−2</SUP> calculated by the Bean model. The superconducting properties such as <I>T</I> <SUB>c</SUB> and <I>J</I> <SUB>c</SUB> of thin films are comparable to those of bulk single-crystal samples. The superfluid plasma frequency (<I>λ</I> <SUB>p,S</SUB>) of Ni-Ba122 thin film is ∼7033 cm<SUP>−1</SUP> obtained by optical spectroscopic technique. Based on this plasma frequency, we obtained the London penetration depth (<I>λ</I> <SUB>L</SUB>), ∼226 nm at 8 K, which is comparable to those of optimally Co- and K-doped BaFe<SUB>2</SUB>As<SUB>2</SUB> single crystals.</P>

A molecular basis behind heterophylly in an amphibious plant, <i>Ranunculus trichophyllus</i>

Kim, Juhyun,Joo, Youngsung,Kyung, Jinseul,Jeon, Myeongjune,Park, Jong Yoon,Lee, Ho Gyun,Chung, Doo Soo,Lee, Eunju,Lee, Ilha Public Library of Science 2018 PLoS genetics Vol.14 No.2

<▼1><P><I>Ranunculus trichophyllus</I> is an amphibious plant that produces thin and cylindrical leaves if grown under water but thick and broad leaves if grown on land. We found that such heterophylly is widely controlled by two plant hormones, abscisic acid (ABA) and ethylene, which control terrestrial and aquatic leaf development respectively. Aquatic leaves produced higher levels of ethylene but lower levels of ABA than terrestrial leaves. In aquatic leaves, their distinct traits with narrow shape, lack of stomata, and reduced vessel development were caused by <I>EIN3</I>-mediated overactivation of abaxial genes, <I>RtKANADIs</I>, and accompanying with reductions of <I>STOMAGEN</I> and <I>VASCULAR-RELATED NAC-DOMAIN7</I> (<I>VDN7</I>). In contrast, in terrestrial leaves, ABI3-mediated activation of the adaxial genes, <I>RtHD-ZIPIIIs</I>, and <I>STOMAGEN</I> and <I>VDN7</I> established leaf polarity, and stomata and vessel developments. Heterophylly of <I>R</I>.<I>trichophyllus</I> could be also induced by external cues such as cold and hypoxia, which is accompanied with the changes in the expression of leaf polarity genes similar to aquatic response. A closely-related land plant <I>R</I>. <I>sceleratus</I> did not show such heterophyllic responses, suggesting that the changes in the ABA/ethylene signaling and leaf polarity are one of key evolutionary steps for aquatic adaptation.</P></▼1><▼2><P><B>Author summary</B></P><P>Evolutionary adaptation into aquatic environment is widely observed in diverse clades of land plants. To understand the molecular basis behind such adaptation, we analyzed <I>Ranunculus trichophyllus</I>, an amphibious plant producing different leaf shape depending on the growth conditions. Aquatic leaves of this plant produce higher levels of ethylene, which causes overactivation of genetic circuits composed of <I>EIN3</I>, an ethylene signaling transducer, and abaxial genes that suppress genes regulating stomata and xylem development. In contrast, terrestrial leaves produce higher levels of ABA, which activates adaxial genes and causes activation of stomata and xylem developments. Such changes in the ABA/ethylene signaling and leaf polarity after submergence were not observed in the closely-related land plant <I>R</I>. <I>sceleratus</I>, indicating that they are key evolutionary steps towards aquatic adaptation.</P></▼2>

Investigation of 3D Printed Electrically Small Folded Spherical Meander Wire Antenna

Myeongjun Kong,Geonyeong Shin,Su-Hyeon Lee,Ick-Jae Yoon 한국전자파학회JEES 2017 Journal of Electromagnetic Engineering and Science Vol.17 No.4

The radiation properties and fabrication precautions of a 3D printed, electrically small folded spherical meander wire monopole antenna are investigated. The antenna is self-resonant and shows sufficiently high radiation efficiency at an electrical size ka of 0.4, with the radiation quality factor Q approaching the lower physical bound. In antenna fabrication, the possible structural deformation due to gravity is examined before the antenna frame is 3D-printed. The required conductivity is achieved by multiple manual paintings of a silver paste. The radiation efficiency and pattern show very good agreement with the computed expectations, whereas the resonant frequency deviates by 11.8%. The method to minimize such a fabrication error when using 3D printing technology for wire antennas is discussed.

Synthesis and optimization of Ag-ZnO heterojunction composite nanofibers for enhanced photocatalytic activity

Myeongjun Ji,Young-In Lee 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.4

In this study, Ag-ZnO heterojunction composite nanofibers with an average diameter of about 100 nm and coupled Agnanoparticles with a size of 10 nm were synthesized by facile electrospinning followed by thermal treatment whereby the Agcontent was tuned by controlling the precursor concentration. Rhodamine B (RhB) was employed as a representative dyepollutant to evaluate the ultraviolet (UV) and visible light photocatalytic activity of the pure ZnO and Ag-ZnO compositenanofibers. The photocatalytic activity of 1.5 at% Ag-ZnO nanofibers toward RhB degradation was the greatest,outperforming pure ZnO nanofiber by a factor of more than 5 times. Further increasing the Ag content led to lowerphotocatalytic activity, most likely due to the growth of the Ag nanoparticles. It was found that the enhanced photocatalyticactivity is caused by the heterojunction structure promoting the charge separation of the photogenerated charge carriers, whilethe effect of surface plasmon resonance by the Ag nanoparticles on the photoreactivity is insufficient. The Ag-ZnO nanofibersshow great promise as innovative and highly performing photocatalyst for photocatalytic waste-water treatment.