Systematic Control of Sulfur Chain Length of High Refractive Index, Transparent Sulfur-containing Polymers with Enhanced Thermal Stability

최건우,장원태,최지성,차국헌,임지우,임성갑 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.1

감성분석을 활용한 컨테이너 시장 예측

최건우,윤희성,김동원 한국해양수산개발원 2019 해양정책연구 Vol.34 No.2

This study attempted to analyze the container shipping market using sentiment analysis. Text data captured from Lloyds List, Journal of Commerce and Baltic Exchange market reports from January to December 2018 was used as input data. Three types of sentiment dictionaries, i.e. NRC, Bing and Afinn, were used to measure the sentment of the text and the results were compared to the container spot market. The results from Bing and NRC showed a correlation of over 60% with the direction of the spot market movements, while Afinn produced a correlation of 51%. This research is meaningful in demonstrating the applicability of sentiment analysis to short-term forecasts in the freight market. A scientific approach to ‘market sentiment’ is expected to enhance the performance of shipping companies. 본 연구에서는 감성분석을 이용해 컨테이너 시장을 분석했다. 이를 위해 로이즈리스트의 기사를 수집하였으며 3개의 감성사전을 이용해 컨테이너 운임 시장과 비교분석하였다. 분석 결과 Bing, NRC 감성사전에서는 60% 이상, Afinn은 약 51%의 정확도를 기록했다. 이번연구는 컨테이너 운임시장의 단기예측에 감성분석을 적용했다는데 의미가 있으며, 시장 심리에 대한 과학적인 접근은 해운회사의 성과 향상에 긍정적인 영향을 미칠 것으로 예상된다.

부산항 컨테이너 환적요인에 관한 실증분석

최건우,김은수,강임호,하태영 한국해양수산개발원 2016 해양정책연구 Vol.31 No.2

The container transshipment volume of the port of Busan, with the No. 3 world ranking in 2015 followed by Singapore and Hong Kong, has increased by 15.6 percent year by year since 2000. In recent years, the port of Basan has still retained the higher growth rate with the value of 7% in the transshipment throughput, even though those of the port of Singapore and Hong Kong have been decreased. This study analyzed to find out which determinants affect the transshipment volume of the port of Busan. The study picked out the five main determinants or independent variables, such as ships' operating costs of carriers, location, the volume of the Northern Chinese seaports, port's efficiency, and the size of containership in the literature reviews. The empirical analysis was done with some proxy variables with the quantitative values which were consisted of time-series data sets. The Unit Root Test and Co-integration Test were done for all of time-series variables in the models. The results indicated that all variables(Cost, North-China port throughput, etc.) could affect the container transshipment throughput of the port of Busan. Especially the study found out that Busan port’s networks would be one of the most influential determinants, which results is related with previous studies. 부산항은 2015년 기준 세계 3위의 환적화물 처리 항만으로 2000년 이후 연평균 15.6%씩 성장하였다. 최근 세계 1, 2위의 환적 처리항만인 싱가포르, 홍콩항의 물동량 하락세가 나타났으나 부산항은 여전히 7% 이상의 높은 증가세를 유지하고 있다. 이에 본 연구는 부산항 환적물동량이 왜 지속적으로 증가하는지, 어떠한 요인들이 환적 물동량에 영향을 미치는지 분석했다. 이를 위해 기존의 선행연구에서 주로 사용된 설문조사가 아닌 대리변수를 이용한 실증 분석을 실시하였다. 실증분석 결과 부산항 네트워크, 북중국항만, 선석 효율성 등의 요인이 부산항 환적 물동량에 영향을 미친 것으로 나타났다.

톰슨 샘플링 기반의 신약 후보 물질 디자인을 위한 심층 생성 모델

최건우,장효순,서상민,최종환,김병주,박상현,최상민,박치현 한국정보과학회 2022 데이타베이스 연구 Vol.38 No.3

De novo drug design approach, which aims to create a completely novel molecules non-existent in the previous compound library, adopts various machine learning methods such as generative model, reinforcement learning and optimization algorithm. Most of the existing studies suggest the generative model which controls one property. Along with creating a generator, one of the most important factors to be considered in designing an algorithm is an optimization method which can simultaneously guarantee various properties that the molecules must have. One way to implement it on a deep generative model is to estimate the posterior distribution through sampling and then optimize the generator in a direction to satisfy multiple purposes. In this manner, we propose a novel method which optimizes the posterior distribution of the generative model with the generated data which satisfy multiple objectives through self-data augmentation and learning by incorporating the Thomson sampling technique into VAE (Variational Auto-Encoder). To demonstrate the feasibility of the proposed method, we aimed at generating molecules for BCL2 family proteins and compared the binding affinity of the proposed method with several baseline models. The practical usability of the proposed method was confirmed by measuring the various chemical properties and synthesizability of the molecules. 심층 생성 모델, 강화학습, 최적화 알고리즘 기반으로 새로운 신약 후보 물질을 생성하는 약물 디자인 연구는 대부분 단백질 한 개의 기능을 조절할 수 있는 저분자화합물 디자인 모델을 제시하고 있지만, 목적하는 적응증의 메커니즘에 따라 여러 단백질의 기능을 조절하고, 단백질 외에 화학적 특성을 고려할 수 있는 다중 목적 최적화 기반의 약물 디자인 방법론이 요구되고 있다. 심층 생성 모델로 이를 구현할 수 있는 한 가지 방법은 샘플링을 통해 사후 확률 분포를 추정한 후 다중 목적을 만족하는 방향으로 생성 모델을 최적화하는 것이다. 이를 위해 본 연구에선 심층 생성 모델인 Variational Auto Encoder에 톰슨 샘플링 기법을 접목하여, 자체 데이터 증강과 학습을 통해 다중 목적을 만족하는 데이터를 생성하고, 이를 통해 생성 모델의 사후 분포를 최적화하는 방법을 제안한다. 본 연구에서는 BCL2 패밀리 단백질들을 표적으로 약물 생성을 제안하는 모델과 여러 베이스라인 모델이 생성한 화합물들의 결합 친화도를 비교하였으며, 생성된 물질에 대한 화학적인 특성 지표와 물질의 합성 가능성 스코어를 통해 제안하는 방법의 실제 활용 가능성을 제시하였다.

Vapor-Phase Synthesis of Sulfur-Containing Polymers for High Refractive Index and Enhanced Thermal Stability

최건우,장원태,이원석,최지성,강민정,김지한,차국헌,임지우,임성갑 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.1

Is It Possible to Achieve IMO Carbon Emission Reduction Targets at the Current Pace of Technological Progress?

최건우,윤희성,황수진 한국무역학회 2022 Journal of Korea trade Vol.26 No.1

Purpose – The primary purpose of this study is to verify whether the target set out by the International Maritime Organization (IMO) for reducing carbon emissions from ships can be achieved by quantitatively analyzing the trends in technological advances of fuel oil consumption in the container shipping market. To achieve this purpose, several scenarios are designed considering various options such as eco-friendly fuels, low-speed operation, and the growth in ship size. Design/methodology – The vessel size and speed used in prior studies are utilized to estimate the fuel oil consumption of container ships and the pace of technological progress and Energy Efficiency Design Index (EEDI) regulations are added. A database of 5,260 container ships, as of 2019, is used for multiple linear regression and quantile regression analyses. Findings – The fuel oil consumption of vessels is predominantly affected by their speed, followed by their size, and the annual technological progress is estimated to be 0.57%. As the quantile increases, the influence of ship size and pace of technological progress increases, while the influence of speed and coefficient of EEDI variables decreases. Originality/value – The conservative estimation of carbon emission drawn by a quantitative analysis of the technological progress concerning the fuel efficiency of container vessels shows that it is not possible to achieve IMO targets. Therefore, innovative efforts beyond the current scope of technological progress are required.

컨테이너 공급망 충격으로 인한 항만의 영향 분석 -부산항을 중심으로-

최건우,윤재웅,이주원,고병욱 한국해양비즈니스학회 2023 해양비즈니스 Vol.- No.55

Due to the increase in container traffic during the corona pandemic, congestion occurred in major ports worldwide. In this study, as a result of analyzing the cause of port congestion with the Lasso model, focusing on the case of Busan Port, it was found that it was due to the increase in transshipment volume and the decrease in reliability of container ships. In particular, unlike import and export cargo, it is difficult to adjust the timing for transshipment cargo, and terminal congestion increases due to movement between terminals. Therefore, the newly built Jinhae New Port needs to improve terminal operation efficiency through strategic integration. As a result of estimating the recovery period of port congestion due to the decrease in transshipment volume and punctuality, it was estimated that it would normalize within 1-2 months. Although this study is meaningful in that it estimated the period required to recover from shock in Busan Port, it has limitations in calculating resilience for temporary shock.

KY 컨버터의 피드백 보상 회로 설계에 관한 연구

최건우(GUN-WOO CHOI),문병희(BYUNG-HEE MOON),정해영(HAI-YOUNG JUNG),김성환(SUNG-HWAN KIM),이석현(SEOK-HYUN LEE) 대한전기학회 2019 대한전기학회 학술대회 논문집 Vol.2019 No.4

컨테이너 하역요율 하락은 소비자잉여를 증가시켰는가?

최건우(Choi, Gun-Woo),김찬호(Kim Chan-Ho),김용규(Kim, Young-Kyu) 한국항만경제학회 2016 韓國港灣經濟學會誌 Vol.32 No.3

국내 컨테이너 물동량 증가로 이를 처리하는 하역산업 증가하였다. 하지만 1999년 이후 하역요율의 신고제 전환과 시설 공급 과잉으로 인해 하역사간의 과도한 요율경쟁이 발생하여 2015년 기준 컨테이너 하역요율이 2000년에 비해 절반 이하로 하락하였다. 이에 본 연구에서는 하역 요율의 하락이 항만물동량 수요에 영향을 미쳐 항만 하역산업의 시장을 확대 시켰는지? 아니면 과도한 요율 경쟁으로 인해 소비자잉여가 오히려 축소되었는지를 경제학적으로 분석해 보았다. 이를 위해, 본 연구에서는 기존에 항만부문의 경제적 가치를 추정한 연구에서 사용한 직접추정방식이 아닌 수요함수를 이용한 추정방식을 제시하였으며 소비자잉여 추정을 위해 타분야에서 주로 사용된 알렉산더방식 외에 힉스의 수요함수를 이용한 하우스만방식을 이용하여 추정의 신뢰성을 높였다. 그 결과 컨테이너 수출입 수요에 비해 하역요율이 과다하게 하락하여 소비자잉여를 포함한 하역산업의 경제적 가치는 오히려 하락하는 것으로 나타났다. 한편, 향후 환적 컨테이너 물동량을 포함한 경제적 가치추정에 관한 연구가 진행되어야하며 나아가 항만산업 전체로 확대하여 현재 항만부문 예비타당성 조사 표준지침에서 이용되고 있는 경제적 편익 방식을 보완할 수 있어야 하겠다. As increasing of container throughputs, port business market in Korea has been developed. However, due to the introducing of a handling fee reporting system in 1999 and surplus of facilities, port business market in Korea turned into deadly competition with lowering the handling fee. Due to the reasons, the handling fee in 2015 declined as much as 50% of in 2000. Therefore, this study analyzed whether the handling fee decline caused consumer surplus in the port business market of Korea or not. To do that, this study applied a methodology of Alexander for estimating the consumer surplus and Hausman’s model using Hicksian demand. As the result of the analyzing, due to the excessive decreasing of the handling fee compared the import & export demand, consumer surplus of the port business market in Korea was decreased. However, due to the exception of transshipment from demand in this study, transshipment demand is needed to be considered to estimate of economic value of port business market in Korea in the future. Also, economic value of port business including subsidiary businesses will be estimated in order to strengthen the method for estimating economic benefit of port construction.

자연과학편 : 매실(梅實) 농축액(濃縮液) 복용(服用)이 유산소지구력(有酸素持久力) 운동(運動) 후(後) 유산회복률 (乳酸恢復率)에 미치는 영향(影響)

최건우(KunWooChoi) 한국체육학회 1992 한국체육학회지 Vol.31 No.2

The Purpose of this study was to investigate the effect of ume’s extract on the recovery rate after aerobic exercise by sellecting 20 females who were divided 2 groups(experimental group : 10, control group : 10). Experimental group were taked ume’s extract and control group were drinked refind water at 1 min. before aerobic exercise during 2 weeks.To evaluate of recovery level tested the changes of blood lactate on each of immediate, 5, 10, 20 min. after treadmill exercise and recovery rate were calculated as(maximal level-20 min. level)/(maximal level-rest level) × 100.The following is results :1) Recovery rate on experimental group were showed the highest at long treatment as statistical significant(p< 0.05). But control group showed non significant(p >0.05) among 3 conditions.2) On the comparison between groups. experimental group showed more higher level than control group on all conditions.As a conclusion, we can be suggested that ume’s extract have very positive effect on fatigue recovery after aerobic exercise.