• Journal of Hydrogen and New Energy
• /
• v.34 no.4
• /
• pp.342-349
• /
• 2023

In this study, a numerical simulations were conducted to analyze the phase change behavior of a liquid hydrogen storage container. The effects of gravity direction and hydrogen filling rate on boil-off gas (BOG) in the storage container were investigated. The study employed the volume of fluid, which is the phase change analysis model provided by ANSYS Fluent (ANSYS, Canonsburg, PA, USA), to investigate the sloshing phenomenon inside the liquefied hydrogen fuel tank. Considering the transient analysis time, two-dimensional simulation were carried out to examine the characteristics of the flow and thermal fields. The results indicated that the thermal flow characteristics and BOG phenomena inside the two-dimensional liquefied hydrogen storage container were significantly influenced by changes in gravity direction and hydrogen filling rate.

• Journal of the Korean Institute of Navigation
• /
• v.23 no.1
• /
• pp.75-84
• /
• 1999

Although many studies on modelling of port competitive situation have been conducted, both theoretical frame and methodology are still very weak. In this study, therefore, a new algorithm called ESD (Extensional System Dynamics) for the evaluation of port competition was presented, and applied to simulate port systems in northeast asia. The detailed objectives of this paper are to develop Unit fort Model by using SD(System Dynamics) method; to develop Competitive Port Model by ESD method; to perform sensitivity analysis by altering parameters, and to propose port development strategies. For these the algorithm for the evaluation of part's competition was developed in two steps. Firstly, SD method was adopted to develop the Unit Port models, and secondly HFP(Hierarchical Fuzzy Process) method was introduced to expand previous SD method. The proposed models were then developed and applied to the five ports - Pusan, Kobe, Yokohama, Kaoshiung, Keelung - with real data on each ports, and several findings were derived. Firstly, the extraction of factors for Unit Port was accomplished by consultation of experts such as research worker, professor, research fellows related to harbor, and expert group, and finally, five factor groups - location, facility, service, cargo volumes, and port charge - were obtained. Secondly, system's structure consisting of feedback loop was found easily by location of representative and detailed factors on keyword network of STGB map. Using these keyword network, feedback loop was found. Thirdly, for the target year of 2003, the simulation for Pusan port revealed that liner's number would be increased from 829 ships to 1,450 ships and container cargo volumes increased from 4.56 million TEU to 7.74 million TEU. It also revealed that because of increased liners and container cargo volumes, length of berth should be expanded from 2,162m to 4,729m. This berth expansion was resulted in the decrease of congested ship's number from 97 to 11. It was also found that port's charge had a fluctuation. Results of simulation for Kobe, Yokohama, Kaoshiung, Keelung in northeast asia were also acquired. Finally, the inter port competition models developed by ESB method were used to simulate container cargo volumes for Pusan port. The results revealed that under competitive situation container cargo volume was smaller than non-competitive situation, which means Pusan port is lack of competitive power to other ports. Developed models in this study were then applied to estimate change of container cargo volumes in competitive relation by altering several parameters. And, the results were found to be very helpful for port mangers who are in charge of planning of port development.

• Journal of Korea Port Economic Association
• /
• v.36 no.1
• /
• pp.1-22
• /
• 2020

The global container terminal market is predicted to see continued future volume growth. According to Drewry, global container shipments rose by 6.3% year-on-year to 750 billion twenty-foot equivalent units (TEUs) in 2017 and are forecast to experience continued growth to 9.3 billion TEUs in 2022. According to IHS Markit, the global terminal operator (GTO) market is forecast to grow more than 10% annually, up from $2.4 billion in 2017, to exceed $3 billion by 2022. However, Hyundai Merchant Marine is the only real GTO in Korea. In particular, the shipping and port markets are facing drastic changes, both at home and abroad, including a slowdown in the growth of domestic export and import shipments, environmental changes in the container market caused by the trade frictions between the US and China, and increased changes in container shipments caused by the trade frictions between Korea and Japan. In this study, we propose ways for domestic companies to participate in the continuously growing GTO market. After analyzing the current status of the global GTO market, the government expressed a desire to explore ways to establish GTOs through the Port Authority and the Korea Ocean Business Corporation. Therefore, four types of establishment plans were proposed, along with a legal framework for the establishment of GTOs.

• Journal of Korea Port Economic Association
• /
• v.33 no.1
• /
• pp.11-30
• /
• 2017

In addition to recession, world shipping companies are undergoing restructuring due to excess of "World Container Cargo volume" per "World Containership capacity" (in TEU terms). This excess is attributed to the absence of standard index of calculating the "World Containership capacity" (in TEU terms) for "World Container Cargo volume." The purpose of this study is to develop indices and terms: "World Containership capacity (in TEU terms) Standards Index; WCSI" and "World Containership capacity (in TEU terms) Expected Index; WCEI." The comparison between "WCSI" and "WCEI" made in this study is presented below. WCSI (Average voyage 9.3) > WCEI Excess shipping (in TEU terms) WCSI (Average voyage 9.3) = WCEI Optimum shipping (in TEU terms) WCSI (Average voyage 9.3) < WCEI Short shipping (in TEU terms) WCSI=HRCI $1000{\pm}150$ Value approx. The study shows that it is possible to predict "optimal supply of the world's containership capacity" (in TEU terms), "excess or shortage of shipping" (in TEU terms), "order time of container-ship capacity building" (in TEU terms), "order quantity of containership capacity" (in TEU terms), and "stable of World Shipping Companies" by "WCSI" and "WCEI." The development of "WCSI" and "WCEI" aim to help overcome the crisis of recession by establishing effective business strategies for world shipping companies and their supporting companies.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2022.06a
• /
• pp.391-393
• /
• 2022

In recent years, technologies forecasting demand based on deep learning and big data have accelerated the smartification of the field of e-commerce, logistics and distribution areas. In particular, ports, which are the center of global transportation networks and modern intelligent logistics, are rapidly responding to changes in the global economy and port environment caused by the 4th industrial revolution. Port traffic forecasting will have an important impact in various fields such as new port construction, port expansion, and terminal operation. Therefore, the purpose of this study is to compare the time series analysis and deep learning analysis, which are often used for port traffic prediction, and to derive a prediction model suitable for the future container prediction of Busan Port. In addition, external variables related to trade volume changes were selected as correlations and applied to the multivariate deep learning prediction model. As a result, it was found that the LSTM error was low in the single-variable prediction model using only Busan Port container freight volume, and the LSTM error was also low in the multivariate prediction model using external variables.

• Journal of Korea Port Economic Association
• /
• v.36 no.3
• /
• pp.137-154
• /
• 2020

In this study, we analyze the performance of five major port distriparks and present a development plan. The analysis groups the performance into three categories: revitalization of companies in port distriparks, contribution to the port volume, and contribution to the national economy. The key parameters examined in detail include the ratio of hinterland volume to port volume (container and total cargo), port volume growth contribution rate, and job creation. Our results indicate that Gwangyang and Ulsan Ports showed steady growth for all the indicators analyzed, while Gwangyang Port was the only one among the five ports to display consistent steady growth. The results suggest that to achieve consistent growth, high value-added and specialized port distriparks based on the local economy should be established.

• Applied Biological Chemistry
• /
• v.7
• /
• pp.15-19
• /
• 1966

In order to investigate the stability of the major component of malathion E.C. product, dimethyl S-(1, 2-dicarboxyethoxyethyl) dithiophosphate, toward the quality of glasswares as container, the amount of extractable inorganic components, change of pH and decomposition of the major component of the product were examined during the storage in brown-colored bottles of 100 ml. volume from 3 different companies in comparison with that in a Pyrex flask. 1. Malathion E.C. product was put in three containers A,B and C, and any changes occurring in storage were analyzed at three intervals of 60, 120 and 240 days. 2. It was shown that the amounts of Si, Mg, K, Ca, and Na extracted during these periods of storage differed markedly depending on the qualify of container. Container A revealed ten times higher extraction of Na and Ca than container B and C in a 8-month period. 3. Three commercial containers revealed the shift of pH from 6.5 to alkaline reaction in the storage whereas the Pyrex flask did not show any detectable change. In particular, the pH in container A changed to 9.2 in 60 days and 9.9 in 240 days. 4. The decomposition of malathion was the greatest in container A which showed the decomposition of 7.37% in 240 days. On the other hand, 0.5% was decomposed in the Pyrex flask. 5. The decemposition of malathion had a high correlation with the change of pH of water· in the same container, $r^2$ being 0.899. From the above results, it is concluded that about 10% of malathion E.C. product is decomposed in a year due to the alkaline metallic salts extracted from the container when it is stored in glassware bottles of lower quality.

• Journal of Korea Port Economic Association
• /
• v.27 no.2
• /
• pp.355-372
• /
• 2011

Various incentive policies for transshipment cargo have been enforced without any evaluation of the effectiveness. Therefore, the purpose of this study is to evaluate the effect of volume incentive on container transshipment cargo. To be different from previous studies, this study tries to quantitatively assess the incentive effects by using econometric techniques. The result derived from the ARIMA type models indicates that the total amount of the increased transshipment cargo during the last 7 years is about one million TEU. In the meanwhile, the multivariate long run equilibrium model implies that the increased transshipment cargo is less than 0.5 million TEU for the 7 years. Furthermore, the structural break tests indicate that the volume incentive does not change the model structures. It means that the effect of volume incentive is not statistically significant. Consequently, the test results conclude the effect of volume incentive on transshipment cargo is not significant although the volume of transshipment cargo is increased to some extent by volume incentive. Considering the magnitude of BPA's expenditure, we doubt the effectiveness of volume incentive. This study, therefore, encourages the port authority to research a more efficient way to induce transshipment cargo rather than focusing on only volume incentives.

• Journal of Ocean Engineering and Technology
• /
• v.11 no.2
• /
• pp.100-106
• /
• 1997

Viscous flow around an actual ship is calculated by an use of RANS(Reynolds-averaged Navier-Stokes) solver. Reynolds stress is modelled by using k-$\varepsilon$ turbulence model and the law of wall is applied near the body. Body fitted coordinates are introduced for the treatment of the complex boundary of the ship hull form. The transformed equations in the computational domain are numerically solved by an employment of FVM(Finite Volume Method). SIMPLE(Semi-Implcit Pressure Linked Equation) method is adopted in the calculation of pressure and the solution of the disssssssscretized equation is obtained by the line-by-line method with the use of TDMA(Tri-Diagonal Matrix Algorithme). The subject ship model of actual calculation is 4,410 TEU class container carrier. For 4 geosim models the calculated viscous resistancce values are compared with the model test results and analyzed on their componentss. The resistance performance of an actual ship is predicted very resonably, so this mothod may be utilized as a design tool of hull form.

• Journal of Navigation and Port Research
• /
• v.28 no.5
• /
• pp.413-420
• /
• 2004

The Busan New harbor will be opened by 2011, after which it is expected that the marine traffic volume around this area would Increase significantly and that very large ships such as 12,000 TEU container ships would come into the port. Therefore, it is necessary to build a new ships' routeing by considering these factors. In this paper, environmental circumstances, marine traffics, and the preceding studies have been reviewed and ships' routeing is proposed through experts' opinions and Delphi technique. For the purpose of validation, the proposed ships' routeings are reviewed by several guidelines on the ships' routeing and through simulation studies.