• Journal of Advanced Research in Ocean Engineering
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• v.2 no.1
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• pp.40-47
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• 2016

This paper describes the design and performance of a hovering AUV constructed at KMOU (Korea Maritime and Ocean University). Before the field test, we analyzed the dynamic performance of the AUV using a simulation program made by Matlab & Simulink. Also, a PID controller was designed to control the thrusters. Using 4 thrusters (2 vertical and 2 horizontal), the AUV could be controlled using dynamic motion with 4-DOF. A simulation and field test were conducted with way-point tracking, maintaining the desired depth. To perform way-point tracking, the AUV can be fine-tuned to the desired heading angle through the LOS (Line Of Sight) method. This paper shows the results of simulation and field tests.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.189-190
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• 2019

블록체인의 잠재력이 높은 반면, 아직까지는 현장에서 완전히 검증되지 않은 기술이기 때문에 예상만큼 블록체인의 도입이 이루어 지지 않고 있다. 거래 정보에 대해 제 3의 신뢰기관에서 인증하는 기존의 방식과 달리 블록체인은 네트워크 참여자가 작업증명 등의 방식으로 인증하기 때문에 분산 원장 기술로도 불리는데, 이러한 특성으로 인해 네트워크의 규모가 확대될수록 데이터의 신뢰성 및 투명성이 강화되므로 소비자들의 참여를 촉진하는 것이 ····(중략)····.

• Journal of Navigation and Port Research
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• v.46 no.2
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• pp.145-157
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• 2022

Due to the global epidemic of infectious diseases, it has become important for all industries to respond to the risk of infectious diseases. Ports in each country are also responding to the risk of infectious diseases, but the occurrence of infectious diseases in ports of various countries is causing a lot of damage to the logistics of ports. Korea is in the same situation, and cases of infectious diseases in ports are steadily being announced. Therefore, this paper conducted semi-quantitative Bow-Tie risk assessment by substituting measures to cope with infectious disease risks in Korean ports into actual cases of port infectious diseases in Korea, deriving improvements and suggesting directions. As a result, it was concluded that it was necessary to standardize some of the countermeasures against infectious diseases and develop more countermeasures.

• Journal of Navigation and Port Research
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• v.37 no.6
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• pp.699-707
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• 2013

With the increase in the trade volume between countries, the market of freight forwarders industry has been gradually growing. However, not only in Korea, with the number of global freight forwarders increasing, global competition has been increasingly fierce, and domestic freight forwarders are facing enormous challenges, therefore, the relevant policy sectors have carried out a series of supportive policies, while academics have conducted various researches. But most of them have focused on the current situation or the business model, and they could not get feedback on government support policies from enterprises. Using the AHP analysis, this study decided the priority of the government's ongoing supporting policies, compared the cognitive differences among of the companies of 3 different sizes, which was further verified using t-test. Then we compared the government support policies with the actual expectations of the companies to see if they matched on the basis of the previous results of this study, in order to help to strengthen the competitiveness of our freight forwarding industry.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.543-551
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• 2020

In this paper, we introduce a method to improve the accuracy of the length estimation of targets using a radar. The HRRP (High Resolution Range Profile) obtained from a received radar signal represents the one-dimensional scattering characteristics of a target, and peaks of the HRRP means the scattering centers that strongly scatter electromagnetic waves. By using the extracted scattering centers, the downrange length of the target, which is the length in the RLOS (Radar Line of Sight), can be estimated, and the real length of the target should be estimated considering the angle between the target and the RLOS. In order to improve the accuracy of the length estimation, parametric estimation methods, which extract scattering centers more exactly than the method using the HRRP, can be used. The parametric estimation method is applied after the number of scattering centers is determined, and is thus greatly affected by the accuracy of the number of scattering centers. In this paper, in order to improve the accuracy of target length estimation, the number of scattering centers is estimated by using AIC (Akaike Information Criteria), MDL (Minimum Descriptive Length), and GLE (Gerschgorin Likelihood Estimators), which are the source number estimation methods based on information theoretic criteria. Using the ESPRIT algorithm as a parameter estimation method, a length estimation simulation was performed for simple target CAD models, and the GLE method represented excellent performance in estimating the number of scattering centers and estimating the target length.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.509-516
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• 2020

Korea has gradually been developing port distriparks in major domestic trade ports to diversify their function and create added-value. New tenant companies are needed to help achieve these goals, but no research has been done on selection criteria. To provide such criteria, this study conducted a comparative analysis of the productivity of tenant companies in Busan New Port Distripark based on their characteristics. SFP (single-factor productivity) was measured using the operational data of 67 companies in the distripark over the past - three years (2017-2019). The results indicate that the logistics business and the manufacturing business have strengths in cargo volume productivity and in sales productivity respectively. Also, Northern distripark, a relatively older facility, was found to be more productive than Ung-dong distripark. Finally, the effect of investment-both foreign and in FAC/EQ (facility and equipment)-on productivity showed an inverse relationship with productivity, with the companies with under-average investments being more productive than those whose investments were above average. Therefore, to enhance the productivity and competitiveness of port distriparks, tenant companies must be subject to supplemented system and law for increasing employment and cargo volume, and reestablished selection criteria.

• Journal of Navigation and Port Research
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• v.46 no.3
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• pp.216-226
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• 2022

The industry trends of major global shipping and ports in the world are changing rapidly because of the spread of COVID-19, resulting in the reorganization of GVCs by global companies, and strengthening of environmental regulations by IMO. Based on these environmental changes, Busan Port was ranked 5th in the global container port rankings in 2013. However, since the outbreak of COVID-19, Busan Port's global container port ranking in 2020 fell to 7th, behind Qingdao Port. In the post-Corona era, for Busan Port to compete with global container ports and gain a competitive edge in the port, it is necessary to accurately identify the competitive factors of Busan Port and establish a comprehensive policy. Thus, the purpose of this study was to analyze how the competitive factors of Busan Port have changed in the selection of ports by current global shipping companies, compared to the first study conducted in 2005. Additionally, a comprehensive policy plan was established by identifying factors impacting the frequency of future calls as well as the growth potential of Busan Port, through a stepwise multiple regression analysis. As a result of the analysis, it was found that the call preference and growth potential of Busan Port in the post-Corona era are most affected by 'port facilities'. And it was found that the calls frequency in the future is most impacted by 'the geopolitical location' factor.

• Journal of Navigation and Port Research
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• v.46 no.1
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• pp.42-56
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• 2022

Due to the 4th Industrial Revolution announced at the Davos Forum, the World Economic Forum, in 2016, industrial trends around the world are changing rapidly and intelligently. Among them, the digital twin is drawing attention from all industries as a groundbreaking technology that reduces unnecessary costs and trial and error by implementing real objects, systems, and environments in the same way in the real virtual world and using them to perform simulation analysis. In particular, there is a lot of interest in the application of digital twin technology in solving ports safety and efficiency challenges at once. However, there is a lack of in-depth research for the application of digital twin technology in the port, and in particular, there is a lack of research on measurable data for the implementation of the digital twin in ports. The purpose of this study was to increase granularity and connectivity through measurable data investigation for the application of digital twin technology at container ports. Based on the study results, data factors for container port application were classified into crane data, operational data, physical data, and transportation data, and factor composition, correlation with factors, and fitness were confirmed through confirmatory factor analysis.

• Journal of Navigation and Port Research
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• v.46 no.1
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• pp.57-72
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• 2022

The recent increase in international trade volume and explosive increase in cargo volume due to the non-face-to-face society are leading to an increase in risk exposure and safety accidents in the port logistics industry. Consequently, as the atmosphere and consensus on safety are spreading throughout the society, various safety laws are being enacted by the industry. Nevertheless, according to the industrial accidents status analysis by the Ministry of Employment and Labor, the average annual number of injured persons increased by 11.1% and the number of deaths by 4.0% from 2015 to 2019. This means that special attention should be paid to possible future risks and preventive measures for major causes of accidents should be established. Therefore, in this study, risk assessment was conducted based on 5,028 accident cases that were reported by the Korea Occupational Safety and Health Agency for 5 years, from 2016 to 2020, and major risk factors for each industry were derived, and then bow-tie analysis was conducted to perform the risk assessment; Further, the study aimed to derive the causes and preventive measures from the risk factors.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.383-384
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• 2022

Following the development of technologies such as digital twin, IoT, and AI after the 4th industrial revolution, decision-making problems are being solved based on high-dimensional data analysis. This has recently been applied to the port logistics sector, and a number of studies on big data analysis, deep learning predictions, and simulations have been conducted on container terminals to improve port productivity. These high-dimensional data analysis techniques generally require a large number of data. However, the global port environment has changed due to the COVID-19 pandemic in 2020. It is not appropriate to apply data before the COVID-19 outbreak to the current port environment, and the data after the outbreak was not sufficiently collected to apply it to data analysis such as deep learning. Therefore, this study intends to present a port data augmentation method for data analysis as one of these problem-solving methods. To this end, we generate the container stowage situation of the yard through a generative adversarial neural network model in terms of container terminal operation, and verify similarity through statistical distribution verification between real and augmented data.