• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.7
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• pp.901-906
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• 2007

Algorithms of path planning and obstacle avoidance are essential to autonomous mobile robots that are working in unknown environments in the real time. This paper presents a new navigation algorithm for an autonomous mobile robot with vision and IR sensors using fuzzy rules. Temporary targets are set up by distance variation method and then the algorithms of trajectory planning and obstacle avoidance are designed using fuzzy rules. In this approach, several digital image processing technique is employed to detect edge of obstacles and the distances between the mobile robot and the obstacles are measured. An autonomous mobile robot with single vision and IR sensors is built up for experiments. We also show that the autonomous mobile robot with the proposed algorithm is navigating very well in complex unknown environments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.60-61
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• 2013

One of the most important indicators for measuring service level and productivity of the port may be a demurrage rate. Currently, in the case of grain terminal of Busan North Port, demurrage rate are recognized at a very high level, in order to improve this, it is tilted more effort operational. In order to reduce the demurrage, there is a way expansion of facility of hardware, such as the replacement of aging equipment, and how manipulative assignment rules of the apparatus of the operation on the software side, such as changing the order of facility allocation. If the financial reasons are out of question, it is possible to expand to reduce the demurrage rate by operational way. Therefore this paper deals with how to operate some of the allocation rules and silo allocation rules of equipment to reduce the work hours with model and how to operate basic equipment and grain terminal of Busan North Port want to be seen by comparative analysis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.247-253
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• 2006

NSW in Australia is famous for beautiful beaches and water activities. There are now almost 450,000 people who hold a NSW power boat driving licence and 200.000 registered boat owners. The popularity of boating continues to grow with licence and registration figures increasing by 3-4 per cent each year. This is a survey about the guide book for boating licence in NSW. This study outlines the essential information such as the types of licence, registration of vessels, choosing the right boat, maintain vessel, safety equipment and preparing for a safe boating trip. In addition, it touches the technical side like boat handling, water traffic rules, navigation markers, emergency and the ways to avoid them. Recently, more and more people are interested in boating. It forms an important part of recreational and tourism activities. To manage these demands effectively and to provide the orderly and safe leisure hours, it is necessary to induce more organizational and serviceable boating licence system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.72-82
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• 2022

The anchorage among harbour facilities should ensure sufficient water surface area for safe anchoring. A general method is to consider the L.O.A of the target ship and the depth and bottom quality of anchorage to calculate the water surface area of anchorage. However, the gross tonnage is used as a unit of the ship capacity standard of anchorage based on the detailed rules for harbour facilities operation in Korea. In this study, the gross tonnage is converted to L.O.A to calculate the actual anchoring radius of the target ship. This actual anchoring radius exceeds at 25 anchorages (among 90 anchorages) compared with the designated water surface area. Therefore, as an improvement plan of the ship capacity standard for anchorage, L.O.A should be used as a unit for anchorage based on the detailed rules for harbour facilities operation and related Korean maritime laws.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1129-1139
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• 2022

Collision accidents happen frequently. The majority of ships involved in collisions in the coastal areas of Korea are middle and small size ships. The proportion of collision accidents is only 9% of all types of marine accidents; however, the number of casualties resulting from collisions is 34.4% of all human life damages. Generally, as reported by the people involved in these collisions, the navigation lights of the opponent ships were poor and invisible when the accident happened even though the weather and visibility were good. Furthermore, there are many insistences for poor navigation light conditions of the opponent ship in the bay or harbor. Therefore, it is necessary to analyze the present conditions and safety of navigation lights. Therefore, in this study, we examined the rules and books of navigation lights and compared it to that of other transportation systems, such as aircraft, trains, and road vehicles. Furthermore, we analyzed the current marine traf ic circumstances and ship collision accidents that happened in the past 5 years. Additionally, a questionnaire was prepared to gather the opinion of ship experts and secure the objectivity for improvement methods of navigation lights. Finally, methods to improve the navigation lights on ships were devised.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1034-1041
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• 2014

This paper propose a fuzzy inference model for obstacle avoidance for a mobile robot with an active camera, which is intelligently searching the goal location in unknown environments using command fusion, based on situational command using an vision sensor. Instead of using "physical sensor fusion" method which generates the trajectory of a robot based upon the environment model and sensory data. In this paper, "command fusion" method is used to govern the robot motions. The navigation strategy is based on the combination of fuzzy rules tuned for both goal-approach and obstacle-avoidance. We describe experimental results obtained with the proposed method that demonstrate successful navigation using real vision data.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.340-350
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• 2021

This paper proposes a decision support model for USVs to improve the accuracy of collision avoidance decision-making. It is formed by Navigation Safety Domain (NSD) and domain-based Collision Risk Index (CRI), capable of determining the collision stage and risk between multiple ships. The NSD is composed of a warning domain and a forbidden domain, which is constructed under the constraints of COLREGs (International Regulations for Preventing Collisions at Sea). The proposed domain based CRI takes the radius of NSD in various encounter situations as threshold parameters. It is found that the value of collision risk in any directions can be calculated, including actual value and risk threshold. A catamaran USV and 6 given vessels are taken as study objects to validate the proposed model. It is found that the judgment of collision stage is accurate and the azimuth range of risk exists can be detected, hence the ships can take direct and effective collision avoidance measures. According to the relation between the actual value of CRI and risk threshold, the decision support rules are summarized, and the specific terms of COLREGs to be followed in each encounter situation are given.

• Journal of the Korea Computer Industry Society
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• v.2 no.11
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• pp.1365-1372
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• 2001

We have suggested three learning rules and implemented an experimental system that automatically restructures hypertext networks according to their user browsing behavior. The system applies link weights to the hypertext networks and updates these weights according to the learning rules. The learning rules are based on how often a particular hyperlink is being traversed and operate on strictly local information of link traversals. Changes in network structure are fed back to users by dynamic link ordering according to descending link weight. This approach is used collaborative filtering and navigation support techniques. The system has been investigation to be able to structure random hypertext networks into valid representations of their user browsing preferences in experiments.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.90-90
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• 2001

This paper deals with the development of a practical control system or an algorithm for optimal aerobatic maneuvers and aerial combat maneuvers. First, a nonlinear flight trajectory tracking control system is synthesized and used to realize the optimal aerobatic maneuver. Some simulation results show that the trajectory achieved with the proposed tracking system is close to the optimal one. This means that the tracking system presented is the practical and effective method to realize the optimal aerobatic maneuvers. Second, the algorithm for a fighter in air combat is presented. This is a simple algorithm that uses a proportional navigation, some dynamic rules based on the conservation of specific energy and some experiential rules in air combat. However ...

• Journal of Korean Port Research
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• v.13 no.2
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• pp.255-266
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• 1999

The purpose of this paper is to describe the design of the decision support system for container terminal ship planning and to introduce the implemented system. The ship planning in container terminals consists of three major decision processes -the working schedule of gantry cranes the discharging sequence of inbound containers the loading position and sequence of outbound containers. For making these decision the proposed system can provide two ship planning modes the interactive planning mode with user-friendly GUI and the automated planning made. To implement the automated planning routine we acquired the planning rules from the expert planner in container terminals and developed an expert system based on the rules. Finally we evaluated the system developed and the potential for commercialization by using container terminal data.