• Journal of Korean Society of Coastal and Ocean Engineers
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• v.10 no.1
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• pp.18-26
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• 1998

In order to find out hydrodynamic changes due to huge complex constructions in the Keum River Estuary, two-dimensional finite element model is applied. Model results show that gate closing of the estuary dam yields tide amplifications at Kunsan Inner Port to 17 cm and 6 cm of M$_2$ and S$_2$, while 5 cm and 3 cm of amplification at Kunsan Outer Port. Tidal currents in the main channel due to stepwise flow-guide dikes construction have been simulated and show that dynamic equilibrium bottom shear stress is 0.4 N/m$\^$2/ on this Keum River Estuary. Sedimentation rates R have correlation with maximum bottom shear stress (equation omitted), R=-0.37-0.40 ln $\tau$.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.51-52
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• 2012

Safety at sea continues to be an important topic for research. The factors that contribute to safety issues are often complex and unclear. Lack of non-technical skills in such areas as communication, teamworking, situational awareness, decision making etc. are well documented as directly affecting safety in high risk work settings such as on board merchant vessels. Competence in non-technical skills can be affected by various habits and circumstances that influence a worker and result in either positive thinking and behaviour or negative thinking and behaviour. Negative thinking can cause stress, anger, frustration; loneliness etc. and this can possibly result in behaviour or actions that undermine the safety of crew and ship. Factors that may contribute to these negative thoughts and behaviours are many and varied and this paper will be looking at one aspect: mobile phone use. In the Republic of Korea, dependency on mobile phones is uniquely high. Maritime students are also susceptible to such dependency and this paper will demonstrate that the symptoms associated with mobile phone addiction and dependency, and in particular the symptoms of withdrawal, are important factors that need to be mitigated in order to improve safety at sea. Although the benefits of mobile phones are many it will be suggested that over-reliance, dependency or addiction can result in negative thinking or behaviour that may directly or indirectly contribute to the factors that cause incidents and accidents at sea. It will be suggested that the most appropriate method of dealing with this problem is twofold: firstly, through training at the educational level and secondly, by encouraging the shipping industry and government to invest more into providing seafarers with better access to the communication methods that they are used to on shore in order to improve work conditions.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.805-811
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• 2008

This paper presents a design of RFID(Radio Frequency Identification) tag antenna which is available for a vehicle's side mirror and directivity characteristics by mr body. The proposed Tag antenna is designed symmetrical structure to improve the broad bandwidth characteristic and the readable range. A proposed tag antenna($30\;mm{\times}24\;mm{\times}1\;mm$) has resonant frequency at 910 MHz and bandwidth is 780 MHz ($540\;MHz{\sim}1320\;MHz$). The chip impedance is the 16 - $j131\;{\Omega}$ and the complex conjugate impedance of commercial chip has been used for tag antenna design. In order to evaluate effects of tag antenna for side view mirror's permittivity as well as car body(conductor), radiation pattern characteristics and readable range have been calculated and measured. The optimized position for a vehicle's RFID system has been observed in the inside of a side mirror and the calculated results show good agreement with the measured results.

• Journal of Navigation and Port Research
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• v.32 no.6
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• pp.505-513
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• 2008

Regarding the developmental plans for the coastal areas and marine architectures, this study deal with the overall planning of apartment complexes in waterfront areas, focusing upon the analysis of their comfort and convenience factors from the perspective of the potential residence. It also analysis the intra-complex comfort and satisfaction conditions in terms of their floor-by-floor, directional. and location factors. The results of the study are as follows: 1) The order of respondents' preference on directional factor has been found to be: South > Southeast > Southwest > East > others. 2) 67% of the people surveyed on scenery responded that outward view is considered more significant than the directional factor. 3) A comprehensive analysis of floor zone-specific view preference shared that there were only minor differences among quay wall, arc, and river-seashore types. The impact of the characteristics of the marine environments turned out to be a greater point of consideration; showing that the other of floor-preference is: high-level > ultra-high level > middle level > low level.

• Ocean and Polar Research
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• v.40 no.4
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• pp.223-235
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• 2018

This study was carried out to investigate benthic sedimentary environments and benthic polychaetous communities on the coast of Ulsan, located on the southern East Sea of Korea. This survey was conducted at 15 stations, four times seasonally in January, April, July and October 2016. From the coast to the outer sea, surface sediments turned into fine grained sediments. There were complex coarse-grained sedimentary facies in various forms in the coastal zones while those with mud facies were found in the offshore zone. Organic matter content (LOI) and sulfide amount (AVS) recorded extremely high values, and increased from the coast to the outer sea, showing a similar trend to mud content with depth. The benthic polychaetous community revealed a mean density of $525ind./m^2$, and the total species number of species was 84. The major dominant polychaetous species were Magelona japonica, Lumbrineris longifolia and Heteromastus filiformis throughout the four seasons. Magelona japonica was concentrated predominantly in shallow coastal areas, but was present in all the regions of the survey area. Lumbrineris longifolia showed higher density in offshore regions more than 30 m deep, whereas H. filiformis showed higher density in coastal areas less than 30 m in depth. As a result of cluster analysis, the study area was divided into three ecological areas according to species composition, such as the northern coastal area between Ulsan PortOnsan Port, the southern area around Hoeya River and the outer sea area. Benthic environments in the study area, as determined by AMBI and BPI index, maintained a healthy condition in all four seasons with the AMBI at a level above GOOD and BPI at a level above FAIR. As organic matter accumulation continues to take place in the Ulsan coastal area, it is essential that detailed research activities continue to be carried out and ongoing monitoring be maintained.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.494-500
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• 2020

Maneuvering vessels in the harbor is an interesting problem in marine cybernetics. The vessel, operated by the pilot and moving very slowly in shallow water, usually is assisted by thrusters, the main propulsion system, and tugboats. In this paper, we suggest a new vessel berthing technique using dampers (cylinder-type fenders) and a system of winches for complex and dangerous berthing situations. We found that control of the fender stroke and rope tension enabled a safe and quick berthing process. The effectiveness and usefulness of this berthing system was verified using a ship of about 2,000 tons.

• Journal of Korea Port Economic Association
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• v.38 no.2
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• pp.69-80
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• 2022

Road transportation accounts for the largest share of cargo transport in Korea. Inland transportation is not only the beginning and completion point of container transportation, but it is also very complex and has many workers. The main job of container drivers, who play a key role in inland logistics, is to transport containers from ports and terminals to destinations. However, in addition to the main role, various container management obligations, such as cleaning containers and managing damaged containers during the transportation process, are implicitly transferred to container drivers. However, little research has been conducted on this issue. This study identified the working environment of container drivers and empirically analyzed the current status of container management responsibilities by drivers. Furthermore, it analyzed whether there was a difference in the degree of container management requirements by shipping company, terminal, and shipper. Differences in requirements for region(Busan, Kwangyang, Pohang) were analyzed, and improvement measures for the problem of transferring container management were also presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.271-271
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• 2019

Estimating ship motion is difficult because it take place in complex environments.. Estimating ship motion is an important factor in ensuring the safety of ship, so accurate estimates are needed. Existing motion-related studies compare the apparent motion of the model acquired and the reference model by experimenting with the ship motion on a particular alignment, making it difficult to intuitively estimate the hull motion. This study introduces the concept of estimating the characteristics of ship motion as a transfer function through pole-zero interpretation and frequency response analysis by applying the method of transfer function of Linear-Time Invariant system. Ship motion analysis model using Linear-Time Invariant system is consist with 1) wave as input signal 2) ship motion as output signal 3) hull defined as black box. This model can be defined by numericalizing the ship motion as a transfer function and is expected to facilitate the characterization of the ship motion through pole-zero analysis and frequency response analysis.

• Journal of Korea Port Economic Association
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• v.26 no.3
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• pp.130-142
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• 2010

The purpose of this paper is to propose applying agent-based model(ABM) for analyzing logistics system. Logistics problems become more complex and multi-faceted. As a result, the behavior of the system becomes more and more difficult to predict, we see the limitations of the traditional top-down approach in handling complexity. The ABM, that is the bottom-up approach, provides new modeling framework in system modeling. The ABM focuses on the interactions of subsystem or agents in whole system. Then the macroscopic picture of the whole system behavior is emerged as the microscopic interactions of agents are aggregated. The ABM assumes that each agent acts based on simple rules learned from dynamic interactions among other agents or its surrounding environment. The ABM has a great advantage in understanding emergent phenomenon that cannot be explained only through considering individual attributes. The ABM is an extremely useful method to analyze complex system such as logistics system. Therefore, the great research efforts and applications on the ABM to logistics system are encouraged in future.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.29-39
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• 2016

As geopolitical, archaeological and strategic interests on cooperation with countries in the Far Eastern Area is gradually increased, countries are competing to attract or install a logistics or manufacturing hub in their countries. In this study, we investigated the relative importance of factors on the main three and nine detailed criteria from the domestic and overseas experts on Far Eastern Area. Using AHP(Analytic Hierarchy Process) analysis, priority importance of factors was derived. As a result, we find that the most important factor was economic factor. In detail, industrial complex creation was the highest factor and the institutional guarantees for the investment on policy and transportation network was second highest factor. Based on analysis result, specific competitiveness level in the 10 region of Far East was follows. Hunchun, Vladivostok, Yanji, Tumen, Rajin, Hassan, Ussuriysk, Cheongjin, Mihaylov Skiing, Nije Jeuchinski were showed in order. Hunchun showed the highest competitive level in location, topography, compliance to the around cities, transportation network, industrial complex, excellence in logistics facilities, long-term investment plans, institutional guarantees for investment, customs efficiency and political stability. However, in other factors such as population and number of households, public facilities, potential demand and resource utilization, Vladivostok showed the highest level.