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3D CAD 수업에서의 플립드러닝 기반의 PBL 교수학습법 효과 연구
박현하,장성욱,Park, Hyun-Ha,Zhang, Sung-Uk 한국정보통신학회 2022 한국정보통신학회논문지 Vol.26 No.5
이 연구는 플립드러닝 기반의 PBL을 활용한 3D CAD 수업이 전문지식 습득과 인재양성에 미치는 영향을 분석한다. 동의대학교 기계자동차로봇부품공학부 3학년 학생들에게 플립드러닝 기반의 PBL 수업을 구현하였으며, 만족도 및 효과에 대한 설문조사를 실시하였다. 학생들은 대체로 교과목, 교수방법, 비대면 정보교류 등에 대체로 만족하는 것으로 나타났으며, '자동차 CAD 및 실습' 교과목에 대한 지식 습득 및 과정에서 자기주도학습, 문제해결력, 책임감, 성실성, 소통능력 등이 향상되는데 플립드러닝 기반의 PBL이 유의한 영향이 있는 것으로 보였다. 특히 비대면 학습에서도 공학설계수업이 효과적으로 운영될 수 있다는 사실이 입증됨으로써 앞으로 실기 교과목의 영상교육 활용에 기여가 있기를 바란다. 본 연구는 추후 연구를 위한 중요한 지표로서 수업 개선을 위한 정량적 지표로 사용할 예정이다.
박현하(Hyun-Ha Park) 한국기계가공학회 2022 한국기계가공학회지 Vol.21 No.5
In the field of medical and marine industries, antibacterial surfaces have been emerged as one of the most important issues. Recently, many researchers have been studying antibacterial surfaces to kill bacteria or prevent the adhesion of bacteria. In their researches, various materials and structures are suggested to inhibit the adhesion of bacteria or kill the attached bacteria. However, chemical materials such as antibiotics or metal could be toxic. Moreover, frequent use of antibiotics causes super bacteria having resistance to antibiotics. In this study, nano-pillar structured surface was fabricated using polyurethane acrylate (PUA) and the mechanically induced antibacterial function was confirmed based on the fabricated nanostructures. Nanostructures can damage the bacterial membrane of Gram-negative bacteria through stretching of bacterial membrane via interaction with the nanostructures and the bacterial membrane. Consequently, the proposed transparent, flexible and nanostructured PUA films can be one of promising candidates for antifouling and antibacterial surfaces which can be applied in various industries.
Lipid-Hydrogel-Nanostructure Hybrid and Its Anti-Biofilm Properties
Hyun-Ha Park(박현하),Kahyun Sun(선가현),Hoon Yi(이훈),Hangil Ko(고한길),Minho Seong(성민호),Insol Hwang(황인솔),SangHyun Lee(이상현),Minsu Kang(강민수),Hyunwook Ko(고현욱),Hoon-Eui Jeong(정훈의) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12
Despite extensive efforts toward developing anti-biofilm materials, efficient prevention of biofilm formation remains challenging. Diverse polymeric materials with bactericidal or antifouling properties have strong potential as efficient antibiofilm materials. However, approaches based on a single strategy using either bactericidal polymers, antifouling coatings, or nano-patterning of polymers have shown limited performance in the prevention of biofilm formation. This study presents a lipid-hydrogel-nanotopography hybrid that has highly efficient biofilm-resistant properties. The hybrid material consists of nanostructured antifouling, biocompatible polyethylene glycol (PEG)-based polymer covered with a membrane-mimicking, antifouling, biocompatible zwitterionic polymer of 2-methacryloryloxyethyl phosphorylcholine (MPC). Surface chemistry of the polymeric hybrid is analyzed with attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy and x-ray photoelectron spectroscopy (XPS). Based on the unique heterogeneous chemical compositions, the lipid-hydrogel-nanostructure hybrid exhibits superior dual functionalities of antifouling and bactericidal activities against gram-negative and -positive bacteria, compared with those of surfaces composed of single type of polymer.
조영삼(Young-Sam Cho),박현하(Hyun-Ha Park),김재현(Jae-Hyun Kim),김완두(Wan-Doo Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5
Nano/micro column-array structures are usually suggested as dry adhesive structure due to enlargement of contact area between dry adhesive structure and substrate. For the fabrication of column-array structure, UV lithography, molding, and etching techniques are adopted. Because the critical scale of dry adhesive structures exists from hundreds nanometers to tens micrometer, every technique needs expensive mask or mold. In this study, we demonstrate that colloidal lithography, that is, a well-known etching technique using colloid as mask could be a promising fabrication technique for the dry adhesive structure with inexpensive mask.