인공신경망을 활용한 LNG 운임예측

임상섭,안영중 한국컴퓨터정보학회 2022 韓國컴퓨터情報學會論文誌 Vol.27 No.7

LNG is known as the transitional energy source for the future eco-friendly, attracting enormous market attention due to global eco-friendly regulations, Covid-19 Pandemic, Russia-Ukraine War. In addition, since new LNG suppliers such as the U.S. and Australia are also diversifying, the LNG spot market is expected to grow. On the other hand, research on the LNG transportation market has been marginalized. Therefore, this study attempted to predict short-term LNG 160K spot rates and compared the prediction performance between artificial neural networks and the ARIMA model. As a result of this paper, while it was difficult to determine the superiority and superiority of ARIMA and artificial neural networks, considering the relative free of ANN's contraints, we confirmed the feasibility of ANN in LNG 160K spot rate prediction. This study has academic significance as the first attempt to apply an artificial neural network to forecasting LNG 160K spot rates and are expected to contribute significantly in practice in that they can improve the quality of short-term investment decisions by market participants by increasing the accuracy of short-term prediction. LNG는 미래 친환경으로 가는 과도기적 에너지원으로서, 세계적인 친환경 규제, COVID-19 팬데믹, 러시아-우크라이나 전쟁 등을 계기로 엄청난 시장의 주목을 받고 있으며, 미국과 호주 등 새로운LNG 공급처도 다양화되고 있어 LNG 스팟시장이 갈수록 커질 것으로 예상된다. 이에 반해 LNG 운송시장에 관한 연구는 그동안 소외됐었다. 본 연구는 LNG 160K 스팟운임의 단기예측에 연구를 시도하였으며 인공신경망과 ARIMA 모형을 활용하여 예측성능을 비교하였다. 본 논문의 결과, ARIMA 와 인공신경망의 예측성능에 관한 우열을 가리기는 어려웠으나 ARIMA모형이 가지는 데이터 제약이 있으므로 ANN의 상대적인 자유로운 제약조건을 고려하면 LNG 160K 스팟운임 예측에 활용 가능성을 확인하였다. 본 논문은 LNG 160K 스팟운임에 관하여 인공신경망을 적용한 최초의 시도로서학문적인 의의가 있으며, 스팟운임의 단기예측 정확성을 높여 시장 참여자들의 단기투자 의사결정의 질을 높일 수 있다는 측면에서 실무적인 기여를 할 수 있을 것으로 기대된다.

전공별 승선 실습생 인권 통계 분석과 시사점

임상섭,이창희,김종관,정선근,박준모,박상익,김종엽,박성호 해양환경안전학회 2023 해양환경안전학회 학술발표대회 논문집 Vol.2023 No.04

중국 동북3성 기점의 물류 활성화 요인분석

임상섭,이병하,최정환 한국항해항만학회 2023 한국항해항만학회 학술대회논문집 Vol.2023 No.1

중국은 우리나라의 최대 수출입 무역국가로써 우리나라 경제에 매우 중요한 위치에 있다. 특히 동북3성을 기점으로 물류는 지리적, 정치적, 문화적인 중요성을 가지고 있어 국익의 관점에서 물류 활성화는 필수적인 요소로써 연구가 필요하다. 본 연구는 동북3성을 기점으로하는 해상물류에 영향을 미치는 요인을 분석하고 활성화를 위한 정책적 제언을 하였다.

Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

임상섭,문재철,김태원,강충길 대한조선학회 2014 International Journal of Naval Architecture and Oc Vol.6 No.4

In casting steels for offshore construction, manufacturing integral casted structures to prevent fatiguecracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conductedfor integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porositieswere studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects causedby the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemicaland mechanical properties of specimens sampled from the product revealed that target values were quantitativelysatisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded,after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. Nosubstantive differences were found in the mechanical properties before and after welding.

미국 연안해운 물류정책 분석

임상섭,박성호,김종관,전해동,김진권,이윤철,이창희 한국항해항만학회 2022 한국항해항만학회 학술대회논문집 Vol.2022 No.춘계

중국 은일문화의 사대부원림의 관계 -선진시대에서 당조까지-

임상섭,조정송 한국조경학회 1999 韓國造景學會誌 Vol.26 No.4

The purpose of this study is to search into the relation between the chinese seclusion culture and the gentleman's gardens by means of the historical and aesthetic approach. The periodic limits of this study is from pre-Qin to Tand. For gentleman's gardens in Tang dynasty at once got out of the noble's gardens which had imitated the imperial gardens until Tang, and became the origin of the gardens of the literati appearing in post-Tang dynasty. The major findings are as follows : First, in pre-Qin period, the origin of the seclusion culture is classified as the metaphysical seclusion of Taoism and the physical seclusion of Confucianism. Although Pu, Yuan, and Uou which could be said the first step of the chinese gardens were inquired, the clear relation between the seclusion and them is not found. Second, during Qin-Han dynasty, the role of the gardens, as the settings of the seclusion, are comparatively minor, too. But uan Kuang-Han's garden considerably escaped from that of pre-Qin in the aspect of function, and it has the characteristics of recreation. Third, during Wei-Chin and Liu dynasty, two types of the seclusions emerged. One is the small seclusion, and the other the Great Seclusion. Though, as formerly, the contemporary gardens did not escaped from the imperial gardens, Shi Chong's garden can be the setting of the Court Seclusion. But the seven Righteous in Bamboos' and Tao Yuan-Ming's settings of the seclusion were real natural environments rather than gardens. Forth, in Tang dynasty, in spite of relatively low status, Bai Ju-Yi's theory of the middle Seclusion enabled gentlemen to make seclusion in sinecures unlike the court Seclusion. The theoretical background of the Middle Seclusion was Zen Buddhism and the State Examinations System and Bai Ju-Yi's private social position also had an important effect on it. In Tang dynasty, there being nobiliary gentleman's gardens, Bai Ju-Yi's garden, Lushan Caotangyuan, was the setting of the Middle Seclusion. It can be called a real gentleman's garden, for it is simple and small unlike the imperial gardens or the nobiliary gentleman's gardens.

ARIMA-SVM 하이브리드 모델을 활용한 탱커 운임지수 예측

임상섭,윤희성 한국금융공학회 2018 금융공학연구 Vol.17 No.4

The tanker market, unlike the container or bulk carrier markets, is dominated by spot transactions, and short-term forecasts play a crucial role in chartering decisions. A hybrid model suggested by Zhang (2003) was applied to forecast tanker freight indices. The model is a combination of the ARIMA and machine learning models i.e. ANN and the SVM. This paper covers not only the BDTI but also the BCTI, which makes it possible to generalize the results. The data length is 240 months, extending from August 1998 to July 2018. The performance test was carried out for the entire period, as well as for two sub-periods (1998-2008 and 2009-2018). The separation of the sub-period was based on the volatility of the index series. Considering spot market decisions, a monthly forecast was attempted. A period of one month is meaningful because spot transactions in the tanker market extend from 30 to 50 days. The results reveal that the hybrid models perform better than single models; they may be used as a guideline to make better decisions in the tanker market, where the share of spot trading is higher than in other sectors. 탱커시장은 스팟거래의 비중이 상당히 높은 시장으로서 건화물시장이나 컨테이너시장과 달리 단기예측의 중요성이 강조된다. 본 논문은 탱커시황 예측에 기계학습 모델(ANN과 SVM)과 계량모델(ARIMA)을 결합한 하이브리드 모델(Zhang, 2003)을 적용하였다. 탱커시장을 대표하는 BDTI와 BCTI를 연구대상으로 하였으며 연구자료는 1998년 8월부터 2018년 7월까지 240개월이다. 변동성을 고려하여 연구기간을 하위구간 1(1998년∼2008년), 하위구간 2(2009년∼2018년), 전체구간으로 구분하였고 모형의 예측성과를 비교하였다. 단기비중이 높은 거래의 형태를 감안하여 월별예측을 시도하였는데 이는 스팟거래가 20∼50일을 기준으로 하는 계약이기 때문이다. 탱커시황 예측결과는 본 논문에서 제시한 ARIMA-SVM의 모델이 다른 모델들에 비해 성능이 우수하였다. 본 연구는 BDTI와 BCTI를 대상으로 하여 전체 탱커시장을 포괄할 뿐만 아니라 탱커시장에서 비중이 높은 스팟거래의 기간과도 부합하는 결과를 제시하였기 때문에 실무적인 성과로서 의의가 있다. 또한 학문적으로 해운시황예측에 시도되지 않았던 하이브리드 모델이라는 방법론을 제시하였다는 점에서 의미를 찾을 수 있다. 본 논문의 결과는 스팟거래 비중이 높은 탱커시장에 단기예측에 관한 과학적 근거로 제시되어 시장참여자들의 용선의사결정에 실질적으로 도움을 줄 것으로 기대된다.

Prediction Oil and Gas Throughput Using Deep Learning

임상섭 한국컴퓨터정보학회 2023 韓國컴퓨터情報學會論文誌 Vol.28 No.5

97.5% of our country's exports and 87.2% of imports are transported by sea, making ports an important component of the Korean economy. To efficiently operate these ports, it is necessary to improve the short-term prediction of port water volume through scientific research methods. Previous research has mainly focused on long-term prediction for large-scale infrastructure investment and has largely concentrated on container port water volume. In this study, short-term predictions for petroleum and liquefied gas cargo water volume were performed for Ulsan Port, one of the representative petroleum ports in Korea, and the prediction performance was confirmed using the deep learning model LSTM (Long Short Term Memory). The results of this study are expected to provide evidence for improving the efficiency of port operations by increasing the accuracy of demand predictions for petroleum and liquefied gas cargo water volume. Additionally, the possibility of using LSTM for predicting not only container port water volume but also petroleum and liquefied gas cargo water volume was confirmed, and it is expected to be applicable to future generalized studies through further research.

Parametric study of propeller boss cap fins for container ships

임상섭,김태원,이동명,강충길,김수영 대한조선학회 2014 International Journal of Naval Architecture and Oc Vol.6 No.2

The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF) and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD) analysis with a propeller open water (POW) test was performed to check the validity of CFD analysis. The design of ex-periment (DOE) case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA) was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water effici-ency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test result showed that the hub vortex is increased downstream of the propeller.

국제항해상선해기사 수급전망

임상섭,조소현 한국항해항만학회 2022 한국항해항만학회 학술대회논문집 Vol.2022 No.2

본 연구는 국제항해상선 해기사를 중심으로 과학적 모델을 이용하여 수요와 공급 분석을 시도하였으며 식별된 시사점을 바탕으로우리나라 해기사 수급 정책의 방향성과 수립을 위한 근거로 활용하고자 한다.