• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.49-52
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• 2008

The plain and simple shape water front structure were designed and installed for wave protection and wave resistance. But the installation of these plain and simple structure cause deficiency of environmental affinity. Also the resonance phenomena from the reflective wave and shipwave of the harbor incident wave caused high tide and wave, consequently maintaining the tranquility of inside harbor, give difficulty for mooring the ship and loading-unloading, increase the possibility of ship collision at the quray wall and landing place To solve these problems, we develop the environmentally friendly wave dissipation block. And installation efficiency, stability of the blocks through experiment of C.E Block Joint.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.811-814
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• 2009

The HF band maritime communication is have developing to digital methode that techniques should be readied the automatic link establishment of 1:N by coast station to many ship station. Because can use way by polling simply that communication environment calls particular station wicked fellow HF communication states which is much redundancy times for coast station to set link. In amateur radio particular station selective calling do to be using ALE(Automatic Link Establishment) controller by 1:1 automatic link setting way, but expect 1:N link setting by these way in maritime communication very difficult. That is difficult to avoid collision by traffic overload to induce calling of ship stations. Because HF communication considers channel special quality traffic state radio link should be established, and should be applied automatically secures stability of channel as accommodative at traffic overload. In this paper is studied the new radio protocol by 3 step sequency driving of free access, group free access and polling access using multi-tone in single channel.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.192-197
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• 2003

A virtual vessel traffic control system is introduced to contribute to prevent a marine accident, e.g. ship collision or stranding. from happening. The system that comes from VTS limitaions, consists of both data acquisition by satellite remote sensing and a simulation of traffic environment stress (here, INOUE model used) based on the satellite data. Remotely sensed data cab be used to provide timely and detailed information about the marine safety, including the location, speed and direction of ships, and help us operate vessels safely and efficiently. If in the future, e.g. 5-minute after, environmental stress values that a ship may encounter on a voyage can be available, proper actions can be taken to prevent accidents. It lastly can be shown that JERS satellite data are used to track ships and extract their information.

• Structural Engineering and Mechanics
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• v.20 no.4
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• pp.451-463
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• 2005

Structural members commonly employed in marine and off-shore structures are usually fabricated from plates and shells. Collision of this class of structures is usually modeled as plate and shell structures subjected to dynamic impact loading. The understanding of the dynamic response and energy transmission of the structures subjected to low velocity impact is useful for the efficient design of this type of structures. The transmissions of transient energy flow and dynamic transient response of these structures under low velocity impact are presented in the paper. The structural intensity approach is adopted to study the elastic transient dynamic characteristics of the plate structures under low velocity impact. The nine-node degenerated shell elements are adopted to model both the target and impactor in the dynamic impact response analysis. The structural intensity streamline representation is introduced to interpret energy flow paths for transient dynamic response of the structures. Numerical results, including contact force and transient energy flow vectors as well as structural intensity stream lines, demonstrate the efficiency of the present approach and attenuating impact effects on this type of structures.

• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.81-88
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• 2009

An evaluation of the structural integrity of an oceanographic buoy subjected to extreme loads was carried out in this study. Load components, such as the current, waves, and wind load, which were required for the sea's environmental conditions, were calculated precisely. A non linear finite element analysis was conducted to elucidate the structural response of the buoy under extreme environmental conditions. Based on the surface drift velocity scheme, a dynamic impact analysis was also carried out for the case of collision accidents. The proposed numerical technique would be a useful and cost effective tool for design scheme evaluation in the field of oceanographic buoys.

• Journal of Advanced Research in Ocean Engineering
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• v.4 no.4
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• pp.146-162
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• 2018

The unsteady problem of a rigid body impact onto a floating plate is studied. Both the plate and the water are at rest before impact. The plate motion is caused by the impact force transmitted to the plate through an elastic layer with viscous damping on the top of the plate. The hydrodynamic force is calculated by using the second-order model of plate impact by Iafrati and Korobkin (2011). The present study is concerned with the deceleration experienced by a rigid body during its collision with a floating object. The problem is studied also by a fully-nonlinear computational-fluid-dynamics method. The elastic layer is treated with a moving body-fitted grid, the impacting body with an immersed boundary method, and a discrete-element method is used for the contact-force model. The presence of the elastic layer between the impacting bod- ies may lead to multiple bouncing of them, if the bodies are relatively light, before their interaction is settled and they continue to penetrate together into the water. The present study is motivated by ship slamming in icy waters, and by the effect of ice conditions on conventional free-fall lifeboats.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.2
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• pp.175-184
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• 2022

This study analyzed the allocation of the skipper's attention during fishing operation in the wheelhouse of a Korean coastal composite fishing vessel by using video observation. To summarize the results, the ratio of lookout, radar and GPS monitoring, which is essential for prevention of collision at sea, was significantly lower than that of other fishing operation due to the attention concentration on the work place during hauling line. In order to reduce exposure to risk of collisions due to concentration of attention to certain tasks such as line hauling, it is necessary to develop an alert system that can notify the approach of other ships or obstruction throughout the ship using information from radar or the automatic identification system. In addition, the order of attention allocation to devices and facilities obtained in this study is expected to be used as basic data for device or facility layout based on the principle of usage frequency in designing wheelhouse for coastal composite fishing vessels in the future.

• Journal of Navigation and Port Research
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• v.36 no.9
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• pp.721-728
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• 2012

Marine traffic safety of the Vung Tau Waterway, from port limit to Ganh Rai Gulf, plays a crucial role in the economic development of the important triangular economic zone in the south of Vietnam: Ho Chi Minh City, Dong Nai Province, Ba Ria-Vung Tau Province. This paper uses the IWRAP Mk2 program to assess marine traffic safety and shows that in the area there are three parts of fairway have highest risk of collision (from buoys No. 8-9 to buoys No. 1-2 of the Song Dinh fairway; from buoy No. 0 to buoys No. 8-9 and from buoys No. 6-9 to buoys No. 8-9A of the Sai Gon-Vung Tau fairway) and the two areas have highest risk of grounding (the Vung Tau coastline from Ganh Hao to Sao Mai and an area in the Ganh Rai Gulf). In addition, the result of a questionnaire survey on a group of Pilots shows that wind, current and rain/fog have considerable negative effect to ship handling of large vessels in this area. This paper's results will be used in the further research to discover solutions for improving marine traffic safety in the Vung Tau Waterway.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.245-246
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• 2014

This paper suggests the navigation information display system which is based on augmented reality technology and especially focuses on image analysis technology. Navigator has to always confirm the information from marine electronic navigation devices and then they compare with the view of outside targets of the windows. During this 'head down' posture, they feel uncomfortable and sometimes it cause near-accidents such as collision or missing objects, because he or she cannot keep an eye on the front view of windows. Augmented reality can display both of information of virtual and real in a single display. Therefore we tried to adapt the AR technology to help navigators and have been studied and developed image pre-processing module as a previous research already. To analysis the outside view of the bridge window, we have extracted navigational information from the camera image by using image processing. This paper mainly describes about recognizing ship feature by haar-like feature and filtering region of interest area by AIS data, which are to improve accuracy of the image analysis.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.6
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• pp.579-589
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• 2008

In the past few years, there are many studies and researches of the underwater vehicles which are carried out its mission using sonar sensors. MSCL(Marine System Control Lab.) at Inha University developed test-bed small ROV, ISRO. ISRO is an open-frame type and has 4 thrusters. ISRO can control 4 motions i.e surge, sway, yaw and heave with sonar sensors. ISRO is developed for inspection of ship hull, marine structure, plant of lake or river and so on. When ROV ISRO inspects something, it is necessary to control the position of ROV ISRO's for the movement and anti-collision with structures in the underwater. In this paper, we deal with the development of a small ROV and verification of the position control system via simulation and experiment using sonar sensors.