• Journal of the Korean Institute of Navigation
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• v.10 no.1
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• pp.11-17
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• 1986

• The Journal of Korea Robotics Society
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• v.5 no.4
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• pp.302-308
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• 2010

A gradient method can provide a global optimal path in indoor environments. However, the optimal path can be often generated in narrow areas despite a sufficient wide area which lead to safe navigation. This paper presents a novel approach to path planning for safe navigation of a mobile robot. The proposed algorithm extracts empty regions using a ray-casting method and then generates temporary waypoints in wider regions in order to reach the goal fast and safely. The experimental results show that the proposed method can generate paths in the wide regions in most cases and the robot can reach the goal safely at high speeds.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.4
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• pp.229-238
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• 2022

This paper addresses on the International technical trends, standards, and development status of terrestrial radionavigation system to provide more accurate and fail-safe Positioning, Navigation, and Timing (PNT) Information available in maritime navigation environment. We analyze the performance result of pilot service in enhanced Long range navigation (eLoran) testbed environment using Low Frequency (LF) signal, and describe the development status of Ranging-Mode (R-Mode) system using Medium Frequency (MF) and Very High Frequency (VHF) to meet the Harbor Entrances and Approaches (HEA) requirement of International Maritime Organization (IMO) within 10m position accuracy. Furthermore, we present an architecture for integrated service of satellite-terrestrial navigation system and future maritime applicable fields. As the core information infrastructure of future navigation for 4th industrial revolution, this paper will be contributed to determining the direction of present and future to provide fail-safe PNT service with Global Navigation Satellite System (GNSS) based on the technical enhancement of terrestrial integrated navigation system.

• Journal of Navigation and Port Research
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• v.35 no.4
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• pp.281-287
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• 2011

According to the Marine Traffic Safety Law, revised in 2009, Marine Traffic Safety Audit is introduced to secure the safe navigation, to prevent the marine accident and to maximize the efficiency of the port. In this audit system, marine traffic safety assessment is the most important scheme because the primary purpose of the audit system is to identify potential risk elements affecting safe navigation. Even though the reliability of audit result depends on the selection of assessment models, there are no independent assessment models for Korean coastal waters and most of models used in Korea currently are developed by foreign countries. Therefore, the development of the independent assessment model for Korean coastal water is required. This study, prior to the development of independent assessment model, aims to provide a basic data by comparing two foreign assessment models in Ulsan port area with marine accident statistics data.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.491-496
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• 2013

Since IMO(International Maritime Organization, hereafter IMO) has decided the Wing-In-Ground craft as one of the ships, A few regulations and recommendations have been revised and approved internationally and domestically. However, the navigation rules considering types and navigation characteristics to secure the safe navigation of Wing-In-Ground craft are not sufficient and especially, there are no navigation rule between Wing-In-Ground crafts. In this situation, it is judged that the navigation rules related to the Wing-In-Ground crafts in any condition of visibility should be moved to the section of the ones in sight of one another to define the responsibilities between WIG and other vessels, and the new regulation, which Type 'B' and 'C' WIGs should avoid Type 'A' WIG, has to be established to ensure the safe navigation between WIGs on the current laws.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.23-29
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• 2006

From a point of view of suggesting the method to avoid ship's collision, the speed of ships has to be considered sufficiently according to encounter angle of ships. But with respect to the establishment of Safe-Guard Ring of Ship Collision Avoidance Support Model in Close Quarters Situation that had been newly studied to avoid ship's collision, the ratio of own ship' speed to a target ship's speed was limited to about less than 1.7. Therefore in this paper, as doing a study concerned with the establishment of Safe-Guard Ring reflected the encounter angle and the speed of ships, we will propose the new model of ship collision avoidance for safe maneuver of ship's collision avoidance.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.129-145
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• 2020

The article presents a systematic approach to design of marine navigation channels parameters resulting from manoeuvring and operational safety. Relations between the parameters of waterway system elements and the conditions of safe ship operation have been determined and the objective function of waterway parameters' optimization problems has been minimized with respect to variables of construction and operation costs. These costs have been functionally associated to variables of channel width at the bottom and fairway depth. The method of fairway's width computation at specified safe depth at the preliminary and detailed stages of waterway design has been proposed. The results of this method application have been illustrated with two examples: 1. The modernization of Szczecin-Swinoujscie fairway aimed at accepting vessels of 60,000 DWT capacity. 2. Construction of an approach channel leading to a newly built container terminal in Swinoujscie harbour (Poland), handling ocean-going container ships of 20,000 TEU capacity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.263-266
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• 2017

Numerous maritime safety technologies and systems are being developed to support safe navigation at Sea. e-Navigation is a representative system for maritime safety. It is being developed to maximize the ships safety by applying most maritime safety technologies. The e-Navigation system is being developed by the International Maritime Organization (IMO) with the aim of introducing it by 2019. South Korea has already recognized the importance of maritime safety support technology and is actively introducing e-Navigation. Korean e-Navigation is being designed to provide diverse functions for maritime safety, such as providing an optimal safe route, risk analysis, and weather information. Service modules that provide e-Navigation's each function use different types of data that are difficult to configure as a single database. In this paper, we analyze the data needed for Korean e-Navigation, the data service system structure and types that can effectively support it.

• Journal of the Korean Institute of Navigation
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• v.22 no.3
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• pp.43-50
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• 1998

This study aims at estimating the in-and-out traffic volume and improving the main channel in Kwangyang Harbour, by utilizing measurement of congestion, i.e, the bumper model. In 2011, the traffic volume of the main channel is 11.96 ships per hour and its traffic density is evaluated 9.53% of the basic traffic capacity. Therefore the existing width of the main channel, 850m is safe enough but the channel requires the traffic separation scheme as suggested in order to secure the safe of the transit vessel.

• Journal of Navigation and Port Research
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• v.30 no.10 s.116
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• pp.779-785
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• 2006

From a point of view of suggesting the method to avoid ship's collision, the speed of ships has to be considered sufficiently according to encounter angle of ships. But the new safe-guard ring of ship's collision avoidance support model in the close quarters is established assuming that the ratio of own ship' speed to a target ship's speed is less than about 1.7. Therefore in this paper, as doing a study concerned with the establishment of safe-guard ring reflected the encounter angle and the speed of ships, we will propose the new model of ship collision avoidance for safe maneuver of ship's collision avoidance.