http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Improvement of Furfuryl Gelatin by Photo-crosslinking for Application to an Injectable Hydrogel
공민선,이현종,임새빈 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1
Hydrogels have been widely used for biomedical applications. In particular, injectable hydrogels are attractive due to the fact that it avoids unnecessary incisions. Still, some injectable hydrogels are degraded fast and mechanically weak. We suggested an injectable hydrogel that is cured by visible light, and the mechanical properties were also promoted for practical use. Furfuryl group modified gelatin (f-gel) was synthesized, and the f-gel was cured by visible light with riboflavin phosphate as a photo initiator. The resultant photo-crosslinked gelatin hydrogel had higher mechanical properties and a slower degradation rate than nonmodified gelatin hydrogel. In addition, BSA was incorporated in the hydrogel matrix as a model protein, and the release profiles were evaluated regarding the gelatin hydrogel concentrations.
그리스 윤활하에서 레이저 표면 텍스쳐링된 그루브 빗살무늬 패턴의 사잇각에 따른 미끄럼 마찰특성 평가
공민선,채영훈 한국트라이볼로지학회 2022 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.38 No.6
Notably, laser surface patterning facilitates tribological applications under lubricated sliding contacts. Consequently, a special pattern that can reduce the coefficient of friction under contact is considered necessary for improved machine efficiency. However, inappropriate pattern designs produce higher friction coefficients and cannot reduce friction. In this study, we use cast iron pins as specimens to investigate their friction and wear characteristics. Moreover, we experimentally investigate the correlation between the friction reduction effect and the design of groove crosshatch patterns fabricated with various angles and widths. We conduct a friction test using a pin-on-disc type tribometer under grease lubrication to study the friction reduction effect of the specimens, and we observe that the average coefficient of friction changes with the crosshatch angle and width. The experiment reveals that grooved crosshatch specimens with a crosshatch angle of 135°maximize friction reduction. The coefficient of friction of the groove specimens with a width of 120 μm is lower than that of the specimens with a width of 200?. The friction reduction effect of the width of the groove is attributed to the density of the groove pattern. Thus, grooved crosshatch patterns can be designed to maximize friction reduction, and the friction property of a grooved crosshatch pattern is found to be related to its width and angle.
공민선,이장호,박범환 한국철도학회 2022 한국철도학회논문집 Vol.25 No.5
Recently, research is being conducted using deep learning for travel mode choice models; however, in Korea such research has been insufficient. In this study, we established a model of inter-city travel mode choice using a deep neural network and a type of deep learning, and compared the estimation results with those of the multinomial logit model. For the model estimation, the O/D data for each mode from the Korea Transport Data Base were used. To compare the performance of the model according to the existence of non-available mode when traveling between regions, the analysis data were preprocessed by dividing them into total O/D data and O/D data with all four modes. In the case of the total O/D data, when using the deep neural network, it was estimated that the MSE decreased by 24.95%, the RMSE decreased by 13.37%, and the MAE decreased by 25.97% compared with the results from the multinomial logit model. Also, in the case of the O/D data with all four modes, it was estimated that the MSE decreased by 42%, the RMSE decreased by 23.85%, and the MAE decreased by 34%. It can be concluded that the introduction of a deep neural network can be helpful to more accurately predict the choice probability in the inter-city travel mode choice context.
공민선,전유성,한윤수 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-
Since the first study on dye-sensitized nanocrystalline TiO<sub>2</sub>, dye-sensitized solar cells (DSSCs) have been considered as a promising alternative to conventional photovoltaic devices due to the merits of low material cost, easy fabrication process and simple fabrication equipment. In this study, all solid-state DSSCs with 2,2',7,7'-tetrakis [N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) as a hole transporting material were fabricated, and their photovoltaic properties were investigated. A device with ZnTFSI<sub>2</sub>-doped Spiro-OMeTAD layer showed a photovoltaic performance of 8.605 mA/㎠ for the short-circuit current, 0.602 V for the open-circuit voltage, and 60.42% for the fill factor, which led to a power conversion efficiency of 3.13%.
공민선,이다영,한윤수 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
Since the introduction of the photosensitized nanocrystalline electrode, dye-sensitized solar cells (DSSCs) have become a low cost alternative to the conventional p-n junction solar cells. However, the potential problems caused by the liquid electrolytes are considered as some of the critical reasons limiting the long-term performance and practicable use of DSSCs. By replacing the liquid electrolyte with a solid-state hole transporting material in DSSCs, dye desorption can be prevented, liquid leakage or evaporation cannot occur, and finally an all solid-state DSSC can be realized, which is easier to encapsulate and to series-connect. In this study, various organic semiconductors with dopants were evaluated to achieve high power conversion efficiency of all solid-state DSSCs.
공공 스마트 공동물류센터 조성 방안 연구 : 경기도를 중심으로
공민선,김병관 한국물류과학기술학회 2023 물류과학기술연구 Vol.4 No.2
Recently, the smartization and enlargement of logistics centers is accelerating, especially in large enterprises. However, small and medium-sized enterprises face many difficulties in building their own smart logistics centers, so public support such as smart joint logistics centers is needed. Accordingly, this study seeks to propose a plan to create and operate a smart joint logistics center that can be jointly used by small and medium-sized enterprises, focusing on Gyeonggi-do. As a result of the survey targeting small and medium-sized logistics enterprises in Gyeonggi-do, small and medium-sized logistics enterprises in Gyeonggi-Do were found to have a high awareness of the need for automation, but a low awareness of the need for joint logist ic. Based on these results, in order to promote the use of smart joint logistics centers, smart joint logistics centers need to provide customized services for enterprises as good as their own logistics centers and to present clear advantages of reducing costs such as rental. The plan presented in this study is expected to reduce the financial burden of Gyeonggi-do and respond flexibly to demand, and can be used as basic data when creating a public smart joint logistics center in other regions.