이중 금속 시안화물 촉매를 이용한 폴리에테르 폴리올 제조에 관한 연구

김수빈,조장호,안호근 한국환경기술학회 2017 한국환경기술학회지 Vol.18 No.5

In this study, we tried to produce polyol[Polypropylene glycol(PPG)] with low unsaturation by using Double metal cyanide(DMC) catalyst instead of basic catalyst. The DMC catalysts were prepared by varying molar ratio of Zn to Co, catalyst preparation temperature and drying temperature. The catalyst performance was evaluated by measuring the physical properties of the prepared PPG. The characterization of DMC catalysts was performed with BET specific surface areas, XRD patterns, and SEM images. OH value, molecular weight, viscosity, and degree of unsaturation for the obtained PPG were measured as physical properties. For the production of PPG, a conventional pressurized batch reactor was used. The BET specific surface area was increased with increasing Zn content in the prepared DMC (Zn/Co) catalysts. The 10:1-Zn/Co catalyst with the highest Zn content had a DMC structure. The catalyst prepared at a preparation temperature of 50℃ and a drying temperature of 100℃ was effective, and the catalyst (10:1-Zn/Co) prepared with a Zn/Co molar ratio of 10:1 showed the highest activity. The molecular weight of the prepared polyol was increased in proportion to the amount of catalyst used, and the degree of unsaturation was almost constant regardless of the amount of catalyst used. The activity of the catalyst was the highest at the reaction temperature of 140℃ or higher. When the reaction temperature was 140℃ over a 10:1-Zn/Co catalyst, the OH value, molecular weight, viscosity, and degree of unsaturation of PPG obtained were 40.48(KOHmg/g), 2,770(g/mol), 610(cp), and 0.0051(meq/g), respectively. The catalysts prepared in this study were thought to be effective for producing polyols with high molecular weight and low degree of unsaturation. 본 연구에서는 염기성 촉매가 아닌 Double metal cyanide(DMC) 촉매를 사용하여 불포화도가 낮은 폴리올[Polypropylene glycol(PPG)]을 제조하고자 하였다. DMC 촉매는 Zn과 Co의 몰 비, 촉매의 제조온도 및 건조온도를 변화시켜 제조하였고, 촉매의 성능은 제조된 PPG의 물성을 측정하여 평가하였다. DMC 촉매의 물성은 SEM 이미지, XRD 패턴 및 BET 비표면적으로 조사하였으며, PPG의 물성은 수산기가, 점도 및 불포화도로 평가하였다. PPG의 제조에는 통상적인 회분식 가압반응장치를 이용하였다. 제조한 DMC(Zn/Co) 촉매에서 Zn의 함량이 증가함에 따라 BET 비표면적은 증가하였다. Zn 함유량이 가장 많은 10:1-Zn/Co 촉매는 DMC 구조를 가짐을 알 수 있었다. 50℃의 제조온도와 100℃의 건조온도에서 제조된 촉매가 효과적이었고, Zn/Co의 몰 비를 10:1로 하여 제조한 촉매(10:1-Zn/Co)의 활성이 가장 높게 나타났다. 제조된 폴리올의 분자량은 사용한 촉매량에 비례하여 증가하였으며, 불포화도는 사용한 촉매량과는 무관하게 거의 일정하였다. 140℃ 이상의 반응온도에서 촉매의 활성이 가장 높게 나타났다. 10:1-Zn/Co 촉매상에서 반응온도를 140℃로 하였을 때, 수산기가 40.4(KOHmg/g), 분자량 2,770(g/mol), 점도 610(cp) 및 불포화도 0.0051(meq/g)인 폴리올이 얻어졌다. 본 연구에서 제조한 촉매는 불포화도가 낮으면서 분자량이 높은 폴리올의 제조에 효과적인 것으로 생각되었다.

비교연구를 통한 미얀마산 속 찬 대나무의 연료품질 평가

김수빈,이창수,박준범 한국신·재생에너지학회 2019 신재생에너지 Vol.15 No.4

In recent days, awareness on Biomass-Solid Refuse Fuel (BIO-SRF) has increased significantly as a potential alternative energy source to solve impending issues on the depletion of fossil fuel and greenhouse gas (GHG) emissions. Among BIO-SRF, biomass derived from wood cultivation has advantages of both CO2 reduction and fuel supplement. Bamboo possesses characteristics suitable for fuel rather than other biomass resources, and trade on bamboo from South East Asia, which has better environmental conditions to produce the bamboo, has increased. Here, a new species of bamboo, ‘Dike bamboo’, which was developed and harvested from Myanmar, has an almost solid culm and thick wall. A comparative study was performed to estimate the feasibility of raw bamboo to be used as a sustainable biomass fuel. The sample was pulverized, and proximate and ultimate analyses were conducted using standard testing methods. The tests showed that Dike bamboo contained higher ash and chlorine contents than other kinds of bamboos, which have adverse effects on the heating efficiency. Although a few properties did not satisfy the required level, its high productivity and density could be considered advantages in economic aspects. In addition, the calorific values were comparable to previously used fuels despite the high ash content.

다성분 단일 합금 타겟과 질소유량의 변화에 따라 증착한 Mo-Cu-(N) 박막의 기계적 특성 및 마찰 특성에 대한 연구

김수빈,윤혜원,문경일,이선영 한국표면공학회 2020 한국표면공학회 학술발표회 초록집 Vol.2020 No.6

CNN을 이용한 Al 6061 압출재의 표면 결함 분류 연구

김수빈,이기안 한국소성∙가공학회 2022 소성가공 : 한국소성가공학회지 Vol.31 No.4

Convolution Neural Network(CNN) is a class of deep learning algorithms and can be used for image analysis. In particular, it has excellent performance in finding the pattern of images. Therefore, CNN is commonly applied for recognizing, learning and classifying images. In this study, the surface defect classification performance of Al 6061 extruded material using CNN-based algorithms were compared and evaluated. First, the data collection criteria were suggested and a total of 2,024 datasets were prepared. And they were randomly classified into 1,417 learning data and 607 evaluation data. After that, the size and quality of the training data set were improved using data augmentation techniques to increase the performance of deep learning. The CNN-based algorithms used in this study were VGGNet-16, VGGNet-19, ResNet-50 and DenseNet-121. The evaluation of the defect classification performance was made by comparing the accuracy, loss, and learning speed using verification data. The DenseNet-121 algorithm showed better performance than other algorithms with an accuracy of 99.13% and a loss value of 0.037. This was due to the structural characteristics of the DenseNet model, and the information loss was reduced by acquiring information from all previous layers for image identification in this algorithm. Based on the above results, the possibility of machine vision application of CNN-based model for the surface defect classification of Al extruded materials was also discussed.

신설 터널굴착이 지중 군말뚝 및 인접 터널의 거동에 미치는 영향 연구

김수빈,오동욱,조현준,이용주 대한토목학회 2022 대한토목학회논문집 Vol.42 No.4

The demand for underground infrastructures such as tunnels is expanding due to rapid urbanization. Tunnels in urban areas are usuallyconstructed adjacent to structures supported by piles. Therefore, a proper understanding of pile-tunnel interaction due to tunnel excavation activities is vital. Thus, in this study, a numerical analysis is conducted to analyze pile settlements, ground surface settlements and shear deformations above an existing tunnel subject to the presence of an adjacent tunnelling, with vertical offsets, the number of piles and the pile spacing considered as variables in the analysis. The results show that the vertical offsets between the tunnel crown and the pile tip generatelarger settlement than the pile spacing. In addition, the vertical offset shows an inversely proportional relationship to the shear deformation due to new tunnelling. 도시의 대형화로 인해 도심지 지하공간은 점점 고밀화되어 가고 있으며, 지하공간 활용에 대한 수요 또한 급격히 증가하고 있다. 도심지에서는 상부뿐만 아니라 지중에도 통신, 교통 등을 위한 지중 구조물 또한 존재하고 있다. 이러한 도심지의 지중에 신설 구조물을 시공할 경우, 상부 및 지중에 존재하는 인접 구조물과의 상호거동에 대한 이해가 필수적이다. 따라서 본 연구에서는 기존 군말뚝 및 운영중 터널에 인접하여 터널이 신설될 경우 침하와 지중의 전단변형을 유한요소해석을 통해 분석한다. 운영 중 터널-말뚝 간의 이격거리, 말뚝 개수, 말뚝 중심간격 등이 변수로 고려되었으며, 수치해석을 통해 말뚝 및 인접 지반 침하를 비교한 결과, 말뚝의 중심간격보다 군말뚝-신설 터널 수직이격거리 및 운영중 터널-신설 터널 간의 수평이격거리가 침하에 더 큰 영향을 미치는 것으로 나타났다. 또한, 구조물 간의 이격거리 증가에 따라 신설 터널 굴착에 따른 전단변형률이 미치는 영향이 감소되는 것으로 나타났다.

다양한 질소 함량에서 증착된 Mo-Cu-N 코팅의 미세구조 및 마찰특성 분석

김수빈,윤혜원,이한찬,문경일 한국표면공학회 2019 한국표면공학회 학술발표회 초록집 Vol.2019 No.11

A tentative evaluation for population establishment of Bactrocera dorsalis (Diptera: Tephritidae) by its population modeling: Considering the temporal distribution of host plants in a selected area in Jeju, Korea

김수빈,김동순 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.2

The Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is a destructive fruit pest in a wide range of cultivated fruit crops and wild plants. This species is a potentially highly invasive fruit fly to Jeju area of Korea. This study was conducted to evaluate the effect of host plants distributed temporally on the population development of B. dorsalis. The temperature-dependent bionomic data for a synonymous group of B. dorsalis, including B. philippinensis, B. papayae, and B. invadens were collected from previous publications and combined to construct a population model of this pest and its thermal constant. We developed a stage-transition model of eggs, larvae and pupae, and an oviposition model for basic population modeling of the four common strains. We investigated the abundance of the host plants of B. dorsalis in a selected site in Jeju and parameterized them in terms of temporal availability to incorporate into the population model. The contribution of host plants for the population growth of B. dorsalis in the selected site was different according to the group of host plants. For example, B. dorsalis populations largely decreased by 93%, when host plants belong to Moraceae (mainly Ficus sp.) were removed in the simulation. Also, we found that the host plants of Prunus persica, Ficus carica, P. mume, Eriobotrya japonica in this order contributed greatly to population abundance of B. dorsalis in the selected area, which was important in terms of mid-season host plants connecting the early adult population of B. dorsalis to citrus plants in the late season. Finally, we discussed a seasonal management strategy against B. dorsalis while considering the availability of host plants and the biology of this fruit fly in an invaded area.

자기자비와 한국인의 심리: 국내연구 메타분석

김수빈,정영주,정영숙 한국심리학회 2017 한국심리학회지 일반 Vol.36 No.3

We employed meta-analysis to identify associations between self-compassion and various psychological variables using Korean literature. Various psychological variables were categorized by mutual consent of researchers who referred to the relative previous researches and hand books of psychology. We gathered 114 dissertations and journal articles published in Korea until now, including a total of 423 effect sizes, and calculated mean effect sizes using CMA2. We found large effect sizes for the relationships between self-compassion and positive psychological variables group of r = .45, and between self-compassion and negative psychological variables group of r = -.44. In addition, sub forms of positive psychological variables group and negative psychological variables group had statistically significant relationships with self-compassion. According to the results, we determined that self-compassion is an important explanatory and meaningful variable in understanding psychology of Korean. This study could help explore and develop the evidence for self-compassion in psychology. 본 연구는 자기자비와 한국인의 심리의 관계를 확인하기 위해, 현재까지 발표된 자기자비 관련 연구들을 수집, 선별기준에 따라 총 114편을 선정하여 메타분석을 실시하였다. 한국인의 심리는 자기자비와의 관련성을 살핀 다양한 심리적 변인들을 연구자간의 합의에 따라 크게 긍정적 심리와 부정적 심리로 분류(대분류) 한 후, 이를 다시 3가지 차원인 적응/부적응, 긍정적/부정적 개인특성, 긍정적/부정적 대인관계 심리 변인으로 군집화(중분류)하고, 각 군집을 5가지 혹은 2가지 유목으로 세분화(소분류)하여 체계적으로 분석ㆍ제시하였다. 자기자비와 한국인의 심리의 관계를 각 분류 차원에 따라 메타분석 한 결과, 대분류인 긍정적 심리(r =.45)와 부정적 심리(r =-.44)는 모두 통계적으로 유의한 큰 평균효과크기를 나타냈고, 중분류는 긍정적 대인관계(r =.36)와 부적응(r =-.38)을 제외한 적응(r =.50), 긍정적 개인특성(r =.48), 부정적 개인특성(r =-.45), 부정적 대인관계(r =-.40) 변인군에서 큰 평균효과크기를 나타내었다. 그 외 소분류 변인군들도 모두 중간 이상의 평균효과크기를 보고하였으며, 특히 심리적 안녕감(r =.57)은 자기자비와의 관계에서 가장 큰 효과크기를 나타내었다. 본 메타분석을 바탕으로 국내 자기자비 연구가 향후 나아갈 방향에 대해 제언하고, 본 연구의 의의를 밝혔다.

기계학습 기반 모델을 활용한 시화호 수질자동측정망 수질평가지수 등급 예측

김수빈 해양환경안전학회 2022 해양환경안전학회 학술발표대회 논문집 Vol.2022 No.06

External Stimuli Responsive Diacetylene-Based Amphiphiles for Smart Inks

김수빈,정광운 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.1