• Journal of the Society of Naval Architects of Korea
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• v.52 no.2
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• pp.135-142
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• 2015

The Anti-Rolling Tank(ART) has an advantage over the other roll stabilizing devices, when ship is staying and working at one site of sea. An important design point of ART is the tank tuning, that is, matching the tank natural period to the ship's roll natural period. Since the load condition and consequently the roll natural period of ship is to be changed widely, the natural period of ART also has to be changed widely. In case of the existing U-tube type ART with a single layer duct, the tank natural period can be changed in a relatively narrow range. This paper suggests a new U-tube type ART system using a double layer duct to enable wide change of ART natural period. Through the roll experiments performed in regular beam waves for a box-type model ship, it is shown that the double layer duct ART has about two times wider period range and a better reducing effect of roll magnitude than the single layer duct ART.

• Journal of Navigation and Port Research
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• v.38 no.2
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• pp.141-146
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• 2014

NIR(New Inspection Regime, hereinafter NIR) relating to the PSC(Port State Contorl, hereinafter PSC) has implemented in Asia-Pacific region under Tokyo-MOU from last January 2014. The most noticable difference between NIR and existing TF(Target Factor, hereinafter TF) is to evaluate company performance and to conduct PSC with flexible inspection interval on the basis of Ship Risk Profile; High Risk Ship, Standard Risk Ship and Low Risk Ship. Particularly deficiencies related to ISM Code, more than 5 deficiencies and detention record have a serious effect on the evaluation of Ship Risk Profile. Therefore ship and company are requested to ensure proper implementation of Safety Management System for the changed PSC tendency. Also RO(Recognized Organization, hereinafter RO) and Administration respectively should take suitable actions different to previous measures, such as implementation of cooperation and support system between vessel and company, changing subject and object for avoiding Mannerism in SMS audit, strengthening supervision on RO by Administration and establishment of private-public Partnership network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1185-1191
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• 2014

An integrated ship area network has functionality of remote control and autonomous management of various sensors and instruments embedded or boarded in a ship. For such environment, a wireless bridge is essential to transmit control and/or managing information to sensors or instruments from a central integrated ship area network station. In this paper, one of reliable schemes of In-ship sensor networks using a Grid-based WPAN is proposed. The proposed scheme is based on a novel grid network which allows a multi-path communication, and is robust, energy efficient. The results demonstrate that the proposed Grid-based WPAN outperforms the IEEE 802.15.4 based network in terms of success ratio and power efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1177-1184
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• 2014

An wired ship area network has functionality of remote control and autonomous management of various sensors and instruments embedded or boarded in a ship. For such environment, the DiffServ (Differentiated Services) realizes that the high-speed real-time flow with the higher priority has the guaranteed minimum data rate and is delivered faster. As a result of this DiffServ effect, the intelligent Ship Area Networks can be implemented. In this paper, an packet drop technique is proposed to outperform the previous RIO (RED In and Out) drop mechanism for DiffServ in ship area networks. the proposed packet drop technique does not manage the individual flows and divides them into several flow groups according to a criterion. And it guarantees the fairness between individual flows in the same QoS class through the group-based control. In simulation results of the proposed packet drop technique, the link utilization decreases than RIO. But it guarantees more data rates to DiffServ flows passing multiple bottleneck links.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.73-80
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• 2004

Recently, many maritime accidents have been increased and the collisions due to human error are given a great deal of proportions out if them We develop the Real-time Collision Risk Monitoring System (CRMS) for the navigational officers to cope with the emergency situation promptly and thus to reduce the probability if casualty. In this study, the risk of collision is evaluated by two kinds if method. The first method is based on Fuzzy algorithm, which evaluates the risk of collision between traffic ships. The second method is based on Environmental Stress (ES) Model, where the total risk if collision is evaluated by the environmental stress felt by human. The developed real-time CRMS has been installed to the ship handling simulator system and its capabilities have been tested through simulator experiments.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.1
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• pp.45-54
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• 2020

In this study, an automatic system for improving the working environment and increasing production efficiency of a laver aquaculture industry in Korea was developed by combining a hydraulic control system and a load cell in a current landing work of the laver. The improved gathering laver system allowed the automatic gathering process of the laver in the sea with the hydraulic control system connected to a cutting machine of the laver on the operating ship, which has been used for gathering the laver semi-automatically in a form of the traditional farming method. The transporting process of the laver from an operating ship to the land was improved as follows. A frame installed on the operating ship and the bag nets were designed and made to hold about 1,000 kg of the laver inside. The bag nets contain the laver on the improved operating ship were tied in knots and hooked on a crane using a load cell. The weight is measured immediately by lifting the bag nets through the load cell system. Weight information is communicated to the fishermen and successful bidders through the application. The advantages of the improved system can help fishermen to fish by improving their working environment and increasing production efficiency. The field survey to improve the landing operation of the laver aquaculture was conducted in Gangjin, Goheung, Shinan, Wando, Jindo, and Haenam in South Jeonnam Province. A total of 10 sites including Gunsan in Jeonbuk Province, Daebu Island in Ansan City, Jebu Island in Hwaseong City in Gyeonggi Province, and Seocheon in Chungnam Province were searched to collect data. Prototypes of the system were tested at the auction house of laver located in Goheung, where laver collection using hydraulic control and landing using road cell could be improved.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.5
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• pp.417-423
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• 2002

In this paper, we propose intelligent steering control system that apply LIBL(Linguistic Instruction Based Learning) method to steering system of ship and take the place of process that linguistic instruction such as officer s steering instruction is achieved via ableman. We embody ableman s suitable steering manufacturing model using fuzzy inference rule by specific method of study, and apply LIBL method to present suitable meaning element and evaluation rule to steering system of ship, embody intelligent steering gear control system that respond more efficiently on officer s linguistic instruction. We presented evaluation rule to constructed steering manufacturing model based on ableman s experience, and propose rudder angle for steering system, compass bearing arrival time, meaning element of stationary state, and correct ableman manufacturing model rule using fuzzy inference. Also, we apply LIBL method to ship control simulator and confirmed the effectiveness.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.3
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• pp.26-37
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• 1998

In this study, the motion control techniques allied to the test ship NARAE are summarized and the results of sea trials are resented. NARAE adopted a hybrid hull form with lower hull and submerged foils. This type of ship has a substantial instability in heave, pitch and roll modes at the foil-borne stage due to little restoring force, so an active control is indispensable to keep the stability. 4-hydraulic actuators with servo valves were installed to drive foils, and several sensors were used to measure the motion of the ship. PID controller was adopted as a motion controller, and for the real-time control, Pentium-class industrial PC was used. Sea trials including take-off, landing, and banked turn maneuvering were carried out for a period of over 3 months and quite satisfactory results were obtained.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.93-97
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• 2002

In this paper, we propose intelligent steering control system that apply LIBL(Linguistic Instruction Based Learning) method to steering system of ship and take the place of process that linguistic instruction such as officer's steering instruction is achieved via ableman. We embody ableman's suitable steering manufacturing model using fuzzy inference rule by specific method of study, and apply LIBL method to present suitable meaning element and evaluation rule to steering system of ship, embody intelligent steering gear control system that respond more efficiently on officer's linguistic instruction. We presented evaluation rule to constructed steering manufacturing model based on ableman's experience, and propose rudder angle for steering system, compass bearing arrival time, meaning element of stationary state, and correct ableman manufacturing model rule using fuzzy inference. Also, we apply LIBL method to ship control simulator and confirmed the effectiveness.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.2189-2196
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• 2015

According to increase environmental pollutions and fuel costs, The study of energy saving in the ship is proceeding actively. PCS is pump control system for cooling system in the ship to improve the energy efficiency by controling rotation speed of sea water pump, fresh water pump and position of 3way valve. In this paper, we develop the PCS simulator that has an environment similar to the cooling system of the actual vessel to ensure reliability of the PCS. Also, PC-based control and data storage system for PCS simulator is developed. To develop this system, National Instrument's cDAQ and LabVIEW are used. Finally, confirm the behavior of the simulator by analyzing the saving data.