안경테 재질에 대한 만족도 고찰

최경서(Kyeong-Seo Choi) 한국안광학회 2017 한국안광학회지 Vol.22 No.4

Purpose: We investigated the satisfaction of wearer about the material of glasses frame which is a tool of visual correction and a fashion item in order to use it as basic data in marketing and fitting. Methods: A questionnaire survey was conducted on the satisfaction of plastic and metal glasses frames for 20‘s and 30’s male and female students. Frequency analysis, X² test, and independent t-test were conducted. Results: Among the respondents, 32.7% showed the tendency to follow the fashion trend, and 12.5% showed the tendency not to follow the trend. The reasons for the replacement of glasses were eyesight change (33.6%), glasses’ damage (27.9%), old design (18.9%) and so on. The glasses’ material used currently is was 50.5% of metal and 25.7% of plastic, showing that metal frames were used more than plastic frames. The reasons for choosing such glasses frames were ‘suitable for face type’ (33.3%), fashion trend (29.7%) and so on. The satisfaction of the respondents was examined. In the case of plastic frames, users were satisfied with price (M = 3.52), weight (M = 3.37) and design (M = 3.36). Gliding (M = 2.91) was the lowest. On the other hand, in the case of metal frames, users were most satisfied with the design (M = 3.80) and satisfied with the order of comfort and weight. Deformation is the lowest satisfaction. For wearer satisfaction, fitting and adjusting according to material should be important. Women tend to follow more fashion and design trends than men (t = −2.989, p<.01). Those who prefer metal frame tends to be more susceptible to trends such as fashion and design than those who prefer plastic one (F = 8.556, P<.001). Conclusions: The satisfaction of the male wearer according to the frame material did not show much difference between the preference of metal frame and plastic frame. On the other hand, women prefer metal frames because they are sensitive to fashionable materials and designs. As the desire of consumers changes according to the fashion, the opticians should fit using the material characteristics so as to satisfy the satisfaction of the wearer, and consider the marketing related to the design.

자동차 시트용 탄소섬유 발열체의 전기적 및 저항 발열 특성

최경은 ( Kyeong Eun Choi ),박찬희 ( Chan Hee Park ),서민강 ( Min Kang Seo ) 한국공업화학회 2016 공업화학 Vol.27 No.2

In this paper, the electrical and resistance heating properties of carbon fiber heating elements with different electroless Ni-P plating times for car seat were studied. The specific resistance and specific heat of the carbon fibers were determined using 4-point probe method and differential scanning calorimetry (DSC), respectively. The surface morphology and temperature of carbon fibers were measured by scanning electron microscope (SEM) and thermo-graphic camera, respectively. From experimental results, the nickel layer thickness and surface temperature of carbon fibers increased with increasing the plating time. However, the specific heat and specific resistance decreased with respect to the increased plating time. In conclusion, the electroless Ni-P plating could improve the resistance heating and electrical properties of carbon fiber heating elements for car seat.

천마의 망막신경세포 활성에 미치는 영향에 관한 연구

최경서(Kyeong-Seo Choi),김지연(Ji-Youn Kim) 한국안광학회 2018 한국안광학회지 Vol.23 No.2

Purpose: G. elata has been actively studied in the treatment of related diseases due to the efficacy of nerve protection and pain relief, but research on the effect of G. elata on our eyes never been explored. Therefore, we investigated on neuronal cell differentiation and antibacterial tests to fine the effect of G. elata on our eyes. Methods: Cell cytotoxicity on retinal ganglion cell 5 (RGC5) and human neuroblastoma (SH-SY5Y) were determined by WST assay. ICC assay was used to observe the effect of the extracts on the differentiation by confocal microscopy. Additionally, the antibacterial effects of Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli were measured by MIC assay and well-diffusion experiment. Results: As a result of the WST assay, it was confirmed that G. elata extracts was not cytotoxic at 50-150 μg/ml and 50-300 μg/ml on RGC5 and SH-SY5Y cell line, respectively. A result of the effects on the cell differentiation by ICC assay confirmed that RGC5 and SH-SY5Y cell lines were stimulated to differentiate to neuronal cells at 100, 150 μg/ml of G. elata extracts. It was found that there was no antimicrobial effect against P. aeruginosa, S. aureus and E. coli by well-diffusion. Conclusions: G. elata extracts is thought to increase the activity of retinal neurons, not antibacterial activity. Therefore, new and pharmacological application studies should be carried out by studying the increase of retinal nerve cell activity using G. elata extracts.

미분쇄 탄소섬유와 카본블랙으로 강화된 천연고무 컴파운드의 기계적 특성

함은광,최경은,서민강,Ham, Eun-Kwang,Choi, Kyeong-Eun,Seo, Min-Kang 한국섬유공학회 2016 한국섬유공학회지 Vol.53 No.2

This study investigated the mechanical properties of natural rubber (NR) compounds reinforced with carbon black (CB) and milled carbon fiber (MCF). An internal mixer and a two-roll-mill were used to prepare natural rubber compounds using various MCF concentrations (0, 2, 6, 12, 17 phr), and to align the MCF in the compounds. The tensile properties, tearing strength, and hardness of the compounds were measured. The study found that compounds with 40 phr CB and 2 phr MCF had the highest tensile strength. Compounds with higher MCF concentrations had greater hardness and tensile stress (100% modulus~300% modulus). Compounds with 40 phr CB and 6 phr MCF were found to have greater tearing strength. These results were probably due to the fact that high elasticity MCF was used, resulting in improved cohesion in the compounds.

스마트 미러를 활용한 노인 건강 증진 자세 분류 시스템

강영서 ( Young-seo Kang ),최경서 ( Kyeong-seo Choi ),이가영 ( Ga-young Lee ),주종화 ( Jong-wha J. Joo ) 한국정보처리학회 2022 한국정보처리학회 학술대회논문집 Vol.29 No.2

코로나 19 로 인해 사회적으로 활동 범위에 제약이 많아져 신체 노화가 진행중인 노년층의 심각한 운동 부족 현상 발생했다. 이에 따라 본 연구는 스마트 미러 트레이닝 프로그램의 범람 속에 신체적인 불편함을 가지고 있는 노인의 건강 증진에 주목하여 스마트 미러와 노인 자세 탐지, 자세 정확성 판단 시스템을 기반으로 한 자세 분류 서비스 제공 프로그램을 제안한다. 스마트 미러에 탑재된 카메라로 받아온 영상을 MoveNet 과 머신러닝 모델을 사용하여 사용자의 동작을 파악하는 방식으로 활동 프로그램을 진행한다. 향후 디지털 소외 계층의 사용 및 노인 자세 데이터 분석에 활용할 수 있을 것으로 기대한다.

탄소섬유 방향이 미분쇄 탄소섬유/카본블랙/천연고무 복합재료의 기계적 물성에 미치는 영향

함은광 ( Eun Kwang Ham ),최경은 ( Kyeong Eun Choi ),고재경 ( Jae Kyoung Ko ),서민강 ( Min Kang Seo ) 한국공업화학회 2016 공업화학 Vol.27 No.2

In this work, the influence of milled carbon fiber direction on mechanical properties of milled carbon fibers/carbon blacks/natural rubber compounds was investigated. The compounds were prepared by adding the 6 phr milled carbon fibers (MCFs) and 40 phr carbon blacks (CBs) into the natural rubber. The MCFs were aligned in a parallel and orthogonal direction in the compounds using two-roll-mill machine. Mechanical properties of compounds were studied by tensile characteristics and tearing strength. As a result, the compounds showed higher tensile strength, 100%~300% modulus, and tearing strength than those of using any other compounds due to the aligning MCFs in parallel. Mechanical properties of the compounds reinforced with non-aligned MCFs were inferior to those of others. Consequently, the parallel aligned MCFs in the compounds led to an increase of tensile properties and improvement of tearing strength, resulted from MCFs with the high elastic modulus.

양액의 순환주기가 담액수경 엽채류의 용존산소 농도, 생육 및 식물영양소의 함량에 미치는 영향

서태철(Tae Cheol Seo),이한철(Han Cheol Rhee),노미영(Mi Young Rho),최경이(Kyeong Lee Choi),윤형권(Hyung Kwon Yun),전창후(Changhoo Chun) (사)한국생물환경조절학회 2009 생물환경조절학회지 Vol.18 No.2

주요 엽채류 7종의 주년 안정생산을 위한 담액수경 재배 시 양액의 순환주기가 양액의 용존산소 농도, 엽채류의 생육, 그리고 식물영양소의 함량에 미치는 효과를 검토한 결과, 양액을 1일 10분 순환 처리구는 정식 13일 후 용존산소 농도가 급격하게 떨어지고 17일 후에는 2.8㎎ㆍL?¹, 20일 후에는 최저 1.5㎎ㆍL?¹까지 낮아졌다. 처리 20일 후 7가지 엽채류의 생체중은 1일 10분 처리구에서는 대조구인 10분 순환/110분 정지 처리구에 비해 0~24% 범위에서 낮아졌으며, 10분 순환/10분 정지 처리구에서는 -2~34% 증가하였다. 양액의 순환주기가 짧을수록 식물체 엽내 P의 함량이 증가하였으며, 식물체의 C/N율과 비타민 C 함량은 감소하였다. 이상의 결과, 담액수경 엽채류의 안정적인 생육과 식물영양소의 흡수를 위해서 2시간에 10분 정도의 양액 순환 처리가 효율적이었다. To determine the effects of circulation frequency of nutrient solution, three frequencies of 10min, on/10min. off; 10min. on/110min. off; and 10min. on/1,430min. off. treatments were applied to leafy vegetable production using deep flow technique (DFT) systems and their growth and phytonutrient content were investigated. In the 10min. on/1,430min. off treatment, dissolved oxygen concentration (DOC) 17 days after treatment decreased to 2.8㎎ . L?¹, known to be a low DOC that causes hypoxia, and thereafter decreased to 1.5㎎ㆍL?¹ 20 days after treatment. Fresh weight of 7 leafy vegetables in the 10min. on/1,430min. off treatment was lower by 0~24% than those in the 10min. on/110min. off treatment, and those in the 10min. on/10min. off was higher by -2~34% than those in the l0min, on/110min, off treatment as control. As the more frequent circulation was applied, the higher phosphorous content and the lower carbon to nitrogen ratio (C/N ratio) and total ascorbic acid contents were resulted. Results indicate that the circulation frequency of 10min. on/110min. off could be recommended for the production of the tested leafy vegetables in OFT systems.

직접메탄올 연료전지용 표면처리된 중형기공 탄소지지체에 담지된 백금-루테늄 촉매의 전기화학적 거동

김병주 ( Byung Ju Kim ),서민강 ( Min Kang Seo ),최경은 ( Kyeong Eun Choi ),박수진 ( Soo Jin Park ) 한국공업화학회 2011 공업화학 Vol.22 No.2

본 연구에서는 중형기공 탄소(MCs)를 표면처리하여, 표면 관능기를 분석하고, 표면처리 효과를 조사하였다. 직접 메탄올 연료전지의 탄소지지체로 중형기공 실리카(SBA-15)를 이용한 전통적인 주형합성법을 이용하여 중형기공 탄소(MCs)를 합성하였다. 중형기공 탄소는 인산의 농도를 각각 0, 1, 3, 4, 및 5 M로 달리하여, 343 K에서 6 h 동안 처리하였다. 그리고 표면처리된 중형기공 탄소(H-MCs)에 화학적 환원방법을 이용하여 백금과 루테늄을 담지하였다. 표면처리된 탄소지지체에 담지된 백금-루테늄 촉매의 특성을 확인하기 위해 비표면적 측정장치(BET), X-선 회절분석법 (XRD), X-선 광전자 분광법(XPS), 투과전자현미경(TEM), 유도결합 플라즈마 질량분석기(ICP-MS)를 이용하였다. 또한, 백금-루테늄 촉매의 전기화학적인 특성을 순환전류전압 실험으로 분석하였다. 표면분석의 결과로부터, 산소를 포함한 화학관능기가 탄소지지체에 도입된 사실을 알 수 있었다. 결론적으로, 4M의 인산으로 표면처리한 H4M-MCs가 백금-루테늄의 균일한 분산과 함께 전기적인 촉매의 성능을 향상시키는 것을 확인할 수 있었다. In this work, the effect of surface treatment on mesoporous carbons (MCs) supports was investigated by analyzing surface functional groups. MCs were prepared by a conventional templating method using mesoporous silica (SBA-15) for using catalyst supports in direct methanol fuel cells (DMFCs). The MCs were treated with different phosphoric acid (H3PO4) concentrations i.e., 0, 1, 3, 4, and 5 M at 343 K for 6 h. And then Pt-Ru was deposited onto surface treated MCs (H-MCs) by chemical reduction method. The characteristics of Pt-Ru catalysts deposited onto H-MCs were determined by specific surface area and pore size analyzer, X-ray diffraction, X-ray photoelectron, transmission electron microscopy, and inductive coupled plasma-mass spectrometer. The electrochemical properties of Pt-Ru/H-MCs catalysts were also analyzed by cyclic voltammetry experiments. From the results of surface analysis, an oxygen functional group was introduced to the surface of carbon supports. From the results, the H4M-MCs carbon supports surface treated with 4 M H3PO4 led to uniform dispersion of Pt-Ru onto H4M-MCs, resulting in enhancing the electro-catalytic activity of Pt-Ru catalysts.