• Journal of Navigation and Port Research
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• v.36 no.10
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• pp.905-910
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• 2012

In early 1990s, the Sea & Air Transport Cargoes (SATC) was increased annually with more than 50% rate due to the rising trade between Korea and China. However, after that, the increasing rate of the SATC was slowdown from the late 1990s, furthermore, recently it became sluggish and declined. This phenomenon is totally different compared to the skyrocketing trade volumes between two countries. In this respect, to forecast the SATC, draw out the factors for activation, and calculate the weight of priority of these factors are urgently needed. To achieve the research objectives, the ARIMA and Fuzzy-AHP were used as research methodology. The estimated volume of SATC using the data from year 2007 to 2012 on the ARIMA model, will be reached approximately 33,000 tons in year 2015. In the mean time, For drawing out and weighing the activation factors for SATC, the Fuzzy-AHP was adopted. As a result, 'Sea & Air transportation-related information system policies' is the most important factor among the principle criteria, and 'the construction of consolidation logistics center' is the most important factor among the 12 sub-principle criteria.

• Journal of Navigation and Port Research
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• v.31 no.6
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• pp.447-454
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• 2007

To assess the port development and maritime traffic environment, the future traffic volume has been estimated using the number of inbound and outbound vessel for a specific port. The estimation of future traffic volume should be considered as an important factor to establish the degree of fairway congestion, the determination of fairway width and the operational role. Until now, the number of in and out vessel for the port has been only estimated mainly, but the type and size of inbound and outbound ships are different depending on the port's characteristics. So, it is difficult to estimate the future traffic volume using the change of only one item. This paper calculates the future traffic volume using the marine traffic characteristic factors as the number of coastal ship and ocean-going ship, the size of ship and the change of cargo volume per a ship etc. And it compared with the results of Artificial Neural Network(ANN) for accurate identification of nonlinear system.

• Journal of Navigation and Port Research
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• v.31 no.6
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• pp.479-484
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• 2007

For calculation of wave field for design of coastal and port structures, generally the wind fields from inland observation record or the predicted waves from deep water wave transformation model are being used. However, for the first case, as we should revise the wave data adopting correcting parameters depending on the distance from the coast and location, it is difficult to extract water waves from wind field. Furthermore, for the second case, because of the calculation which executed under very large grid sizes in the wide domain, the simulation(wave transformation) implied uncertainty in the near shore area and shallow region. So it's difficult to obtain exact data from the simulation. Thus, in this study the calculation of wave field on shallow water is accomplished using the observed data of typhoon 'Maemi' in the Korea Eastern South sea. Moreover, for the accuracy of the calculated wave field, we compared and studied the observed data of wave height and direction on the vicinity of the Ulsan waters. It is proved that the results of this study is more accurate than the existing method with showing ${\pm}1.3%$ difference between observed and calculated wave height distribution in Ulsan waters

• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.119-126
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• 2017

As container vessels get larger, container terminals are also likely to grow. The problem that arises is that the growing volume should be handled in the same amount of time as before. Container terminals are introducing an automation system in order to overcome the limitations of existing manual methods and to continuously reduce operating expenses. Because, Manual handling of carrying containers gate in and out of terminals causes inaccurate data, which results in confusion. An alternative is for containers to be labeled with barcodes that can be scanned into a system with a scanner, but this takes quite a long time and is inconvenient. A RFID system, also known as a gate automation system, can solve these problems by reducing the time of gate management with a technology that detects number identification plates, helping operators more efficiently perform gate management work. Having said that, with this system, when container damage is detected, gate operators make and keep documents manually. These documents, which are insufficient evidence in proving container damage, result in customer claims. In addition, it is difficult for gate operators and other workers to manage containers, exposing them to danger and accidents. This study suggests that if an automation system is introduced at gates, containers can be managed by a video storage system in order to better document damage The video system maintains information on container damage, allowing operators the ability to search for videos they need upon customer request, also allowing them to be better prepared for customer claims. In addition, this system reduces necessary personnel and risk of accidents near gates by integrating a wide range of work.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.429-436
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• 2019

The eLoran system is considered the best alternative because the vulnerability of satellite navigation systems cannot be resolved as perfect. Thus, South Korea is in the process of establishing a testbed of the eLoran system in the West Sea. To provide resilient navigation services to all waters, additional eLoran transmitters are required. However, it is difficult to establish eLoran transmitters because of various practical reasons. Instead, the positioning with NDGNSS/AIS source can expand the coverage and its algorithm with applying continuous waves is under development. Using the already operating NDGNSS reference station and the AIS base station, it is possible to operate the navigation system with higher accuracy than before. Thus, it is crucial to predict the performance when each system is integrated. In this paper, we have developed a simulation tool that can predict the performance of terrestrial integrated navigation system using the eLoran system, maritime NDGNSS station and the AIS station. The esitmated phase error of the received signal is calculated with the Cramer-Rao Lower Bound factoring the transmission power and the atmospheric noise according to the transmission frequency distributed by the ITU. Additionally, the simulation results are more accurate by estimating the annual mean atmospheric noise of the 300 kHz signal through the DGPS signal information collected from the maritime NDGNSS station. This approach can further increase the reliability of simulation results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.69-70
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• 2013

IPCC (International Panel on Climate Change) reported that the arctic sea-ice extent has been decreased by 2.7% per decades since satellite observations in 1978. The decreased sea-ice extent has gained an international attention due to its economical benefits from the NSR (Northen Sea Route). The NRS - not a clearly defined single route, but a number of alternative routes across the top of Russiahas a 37 % reduction in sailing distance, comparing to the SSR (Southen Sea Route) passing thourgh the Suez Canal. Sailing days are consequently reduced from 30 days to 20 days. Also, it is estimated that the Northen Sea has 20 to 25% of world's oil resources and occupies 40% of the world's fishery production. As Republic of Korea was admitted as an observer to the Arctic Council on May 15, 2013, there has been increasing needs to explore new route in the Northen Sea. In this situation, Korea Institute of Ocean Science & Technology (KIOST) is preparing a plan for the development of Arctic-circle Ocean Environmental Information System to support the ice navigation and resource exploration in the Arctic. We will introduce a conceptual design of a satellite-based ice navigation supporting system for the northern sea route.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.147-153
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• 2002

Due to the growth of population and industrial development at the coastal cities, there has been much increase in necessity to effective control of the wastes into the coastal water and river. The amount of disposal at those waters has been increased rapidly and it is necessary for us to track of it in order to keep the water clean. The investigation and research related to the water quality in this region have been conducted continuously but the systematic survey of the disposed wastes at the bottom was neglected and/or minor. In this study we surveyed the status of disposed waste distribution at the bottom coastal water and river from the scanned images. The intensity of sound received by the side scan sonar tow vehicle from the sea floor provides information as to the general distribution and characteristics of the superficial wastes. The port and starboard side scanned images produced from a transducer borne on a tow fish connected by tow cable to a tug boat have the area with width of 22m∼112m, and band of 44m∼224m. All data are displayed in real-time on a high-resolution color display (1280 ${\times}$ 1024 pixels) together with position information by DGPS. From the field measurement and analysis of the recorded images, we could draw the location and distribution of bottom disposals. Furthermore, we made a database system which might be fundamental for planning the waste reception and process control system.

• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.7-13
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• 2015

The number of mobile terminals equipped with a GPS module is steadily increasing today. However, because they using code pseudorange measurements in positioning, the positioning accuracy of mobile terminals is lower than that of those receivers using carrier phases. Especially, the multipath signal causes more significant errors in code pseudoranges. Therefore, the techniques of multipath detection and elimination is necessary. In this study, as an initial analysis of multipath detection and elimination technique development, we tested the feasibility of multipath signal detection using GPS signal strength information. We found that the GPS signal strength increases as the elevation angle gets higher in the open-sky environment. Also, we found that the signal strength decreases when there were some signal reflectors nearby. We checked the repeatability of the signal strength variation characteristics by reflecting repeat time of GPS satellites. As a result, this characteristics repeats almost perfectly when GPS satellites pass the same orbit. Therefore, we found that it is not a temporary phenomenon and the multipath signal detection should be possible by using GPS signal strength information.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.723-734
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• 2009

Container Vessel is becoming larger and faster thanks to the rapid growth of global trade and development of technology. Therefore, 15,000TEU vessel is expected to be ordered in near future. Every nations in north-east Asia are facing strong competition to be logistics hub to get the initiatives of logistics in response to the rapid change of logistics environment. According to the globalization of economy and major ports in this region also are trying to catch big shipping line for their survival. Considering above circumstances of the advent of ultra-large container vessel and spoke-and-hub strategy, it is inevitably necessary to make a fast and accurate vessel job in the terminal in order to be a leading port To meet this objective, current vessel planning system has to be improved innovatively. Therefore, this thesis propose multi distributed vessel planning system which enables multi loading/discharging planning with several planner simultaneously for faster and more accurate than existing planning and enhances quality of planning through information sharing among planners. Also this thesis uses simulation through Arena to verify the efficiency of this multi-distributed vessel planning system.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.691-697
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• 2009

Hardware dedicated off-the-shelf maritime differential GPS RSIM lacks the open architecture to meet all the minimum maritime user requirements and to include future GNSS improvements after recapitalization. This paper carries out a study to replace existing hardware dedicated differential GPS RSIM with software differential GPS RSIM in order to make up the weak point of hardware dedicated off-the-shelf maritime differential GPS RSIM. In this paper, the architecture of software RSIM is proposed for maritime DGPS recapitalization. And the feasibility analysis of the proposed software differential GPS RSIM is performed as the first phase to realize the proposed architecture. For the feasibility analysis, the prototype RF module and DSP module are implemented with properties as wide RF bandwidth, high sampling frequency, and high speed transmission interface. This paper shows that the proposed architecture has the possibility of real time operation of software RSIM functionality onto the PC-based platform through the analysis of computation time. Finally, this paper verifies that the L1/L2 dual frequency software differential RSIM designed according to the proposed method satisfies the performance specifications set out in RTCM paper 221-2006-SC104-STD.