• Korean Journal of Materials Research
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• v.30 no.1
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• pp.22-30
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• 2020

Small fishing vessels are manufactured using FRP. Various studies have been conducted to increase the strength of the composite material by mixing alumina powder with resin. Tensile tests and flexural strength tests are conducted to examine the effect of alumina powder on the strength of GFRP. In the current study, resin/alumina composites at different alumina contents (i.e., 0, 1, 5, and 10 vol%) have been prepared. The physical and mechanical properties of the prepared composites have been investigated. From the results, the tensile strength of the specimen with alumina powder mixed in at 10% shows the highest value of 155.66 MPa. The tensile strength of the specimen mixed with alumina powder increases with the amount of alumina powder impregnated. In the flexural strength test, the flexural strength of neat resin without alumina powder has a highest value of 257.7 MPa. The flexural modulus of ALMix-5 has a highest value of 12.06 GPa. Barcol hardness of ALMix-10 has a highest value of 51. We show that alumina powder leads to decreasing cracks on the surface and decreasing length area of delamination.

• Journal of Navigation and Port Research
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• v.43 no.4
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• pp.250-255
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• 2019

The objective of this study was to analyze the risk of collision accidents to the VTSOs (Vessel Traffic Service Operators) as small ferries and fishing boats are expanded for monitoring targets. The VTSOs was surveyed, the scale of the small vessels defined and the course of general cargo vessels and small vessels along the Busan VTS area investigated for three days. From calculating the risk with CoRI, patterns of increased or decreased risk due to course deviation were similar, and there was no significant difference between the maximum values and the minimum values. In addition, most VTSOs responded that the minimum time required was approximately three minutes to safely instruct in encounter situation, however, the collision risk with a small vessel is very rapidly changing within the three minutes, which is likely to increase the workload and decrease the concentration of the VTSOs. The objective of this study was to investigate the effect on VTSOs with respect to the expansion of small vessels as collision risk, it is expected that it will contribute to the establishment of a suitable scale for the target vessels for VTS through the analysis of each index of the CoRI model and various case studies.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.119-123
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• 2016

In the coastal area, many kind of vessels are operating and exposed to the various marine accidents. In particular, small-size vessels, which are not equipped with the safety equipment, are in the defenceless state to the marine accidents such as the accident according to vessel's own state caused by the diverse reasons and the collision with the neighborhood vessels and objectives. So it is necessary to resolve these situations through the inexpensive equipment. This paper implements the function that can detect vessel's own motion using Smart Phone. if the motion is over the threshold value assigned, this function decides that the current situation is dangerous for this vessel. So this function informs Smart Phone's ower in the vessel and the control center of this situation. This function can be applied to small-size vessels, such as fishing boating, passenger ship, and leasure boat, which have few the safety equipments, and then improve vessel's safety navigation.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.8
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• pp.990-997
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• 2007

In the last 5 years, collisions of fishing vessels have recorded about 54.6% of the total marine accidents. Specially about 64.0% of these collisions were caused by navigator's negligence of watch keeping during works. The purpose of this paper is to develop vessel detecting system that is able to receive the whistle blast of other vessel and make a warning sound and light when the fishermen can not confirm the approaching another vessel on account of fishing works. It is designed to receive the whistle signal blast by a weather tight microphone. The signal is processed by analog active filter in order to enhance the SNR(Signal to noise ratio). And this microprocessor-based system is programmed to do ADC(Analog to digital converting), FFT analysis, controls of warning sound and light.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.956-964
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• 2017

This study contributes to deepening understand of the characteristics of fishing vessel rolling motions to improve the development of capsizing alarm systems. A time domain rolling motion simulation was performed. In order to verify capsizing alarm systems, it is necessary to carry out experiments assuming a capsizing situation and perform actual fishing vessel measurements, but these tasks are impossible due to the danger of such a situation. However, in many capsizing accidents, a close connection with rolling motion was found. Accordingly, the rolling motion of a fishing boat, which is the core of a fishing vessel capsizing alarm system, has been accurately measured and a time domain based on a rolling motion simulation has been performed. This information was used to verify the algorithm for a capsizing alarm system. Firstly, the characteristics of rolling motion were measured through a motion experiment. For small vessels such as fishing vessels, it was difficult to interpret viscosity due to analytical methods including CFD and potential codes. Therefore, an experiment was carried out focusing on rolling motion and a rolling mode RAO was derived.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.920-926
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• 2012

In this paper, marine accidents recently happened in Korea and Japan for 5 years, especially through the analysis of accident characteristics for fishing vessels, including small vessels were analyzed. Also propose a new maritime safety communication network in the form of a comprehensive considering the wave propagation characteristics and operational characteristics of radio communication equipments should be installed in the vessel through comprehensive analysis of the regulation according to the radio equipment and the ship's location identification device installation and operation.

• Journal of Navigation and Port Research
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• v.42 no.4
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• pp.245-252
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• 2018

A method of transmitting an alert signal in case of man-overboard (MOB) systems in a small fishing vessel navigating within coastal area is being operated as VHF-DSC equipment via a distress alert button and V-P ass Equipment via alert button or beacon separation. However, a small fishing vessel with a couple of crews on board is an inappropriate way to alert a man-overboard condition. However, internationally, MOB equipment using VHF-DSC, AIS, and Bluetooth technologies is used to transmit alert signals directly to the mother ship and other radio stations. In order to analyze the performance and technology of the MOB equipment operating in foreign countries, it was confirmed that the alarm signal can be received within a maximum of one nautical mile when the MOB device is on the water surface. An MOB device that meets domestic conditions needs to send an alarm signal to a station within the VHF communication range. However, in order to reduce the false alert signal, it is most appropriate to operate the VHF-DSC radio equipment installed on the ship remotely. Analysis of various technologies connecting the MOB and the VHF-DSC revealed that the Bluetooth system has advantages such as device miniaturization. When an emergency signal is transmitted from the MOB device, it can be received by a dedicated receiver and recognized through an external input terminal of the VHF-DSC equipment generating its own alarm. If the emergency situation cannot be processed at the mother ship, a distress alert is sent to all radio stations via VHF-DSC for response under emergencies faced by small fishing vessels.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.5
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• pp.391-399
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• 2012

This paper presents a method of hull form design for the assistant vessel which is used both as a lighting boat and a fish carrying boat for the fleet of newly formated purse seiner vessels. The optimum hull form parameters are searched by the Sequential Quadratic Programing(SQP) method with the power estimation method of Van Oortmerssen. The prismatic curve is redesigned from that of the reference hull by the Lackenby method. Through the modification of the hull form by using a CAD system, the design procedure is completed. The resistance performances of the reference and the modified hull forms are estimated by using a numerical simulation method. Also, the estimation of seakeeping ability and stability for the modified hull forms are carried out. And then, an optimum hull form is proposed for the designed hull form. Ship model tests for the reference and the designed hull forms are carried out at ship model basin. The results of the experiments show that the effective horse power of the designed hull form is about 22% smaller than that of the reference hull form at design speed. The designed hull form proposed in this study will contribute to the development of the hull form for Korean large purse seiner vessels.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.4_2
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• pp.661-667
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• 2020

The optimal shape modeling of core parts through 3D modeling and structural analysis for the development of small and medium-sized ships. The goal is to improve the efficient structure of the hydraulic system for controlling the rudder among the core steering parts in small and medium-sized ships. Through 3D modeling and structural analysis, a new concept of tiller parts and a double-acting hydraulic cylinder control system were proposed and operational structural stability was evaluated. Structural analysis of the three different tiller designs that can be replaceable onto existing fishing vessels was conducted to derive the final shapes. The emphasis was placed on evaluating the structural stability of the key drive components, the tiller, pin, and cylinder rodin the maximum torque condition of the hydraulic cylinder.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.135-138
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• 2010

The goals of the Global Maritime Distress and Safety System (GMDSS) that initiated by the IMO and supported by IALA, IHO, ITU, IEC and manufacturers are to provide more effective and efficient emergency and safety communications and disseminate Maritime Safety Information (MSI) to all ships on the world's oceans regardless of location or atmospheric conditions. Much of the GMDSS is built on technologies more than 20 years old; some work well; others do not. While GMDSS requirements apply only to SOLAS vessels, there are many other vessels on the water. So some considerations are necessary for non-SOLAS vessels including fishing ships, leisure boats and small boats. This paper describes the analysis of IMO, ITU and IEC meeting results held on recently. Also it gives the trends of the international marine radio standards and its technologies.