• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2007.12a
• /
• pp.296-298
• /
• 2007

국내 해상교량에 건설에 있어서 일반적인 절계 기준에 대한 제도가 정착되지 않아 항만을 이용하는 관계자와 해상교량을 건설하는 주체와의 갈등이 지속적으로 반복되고 있는 실정이다. 이는 항만 이용자 측면에서는 항만의 경쟁력 확보를 위해 선박 통항에 지장을 초래할 수 있는 해상교량에 대해 보다 엄격한 설계 조건을 요구할 수밖에 없고, 반면 해상교량 건설자 입장에서는 교량 건설에 따른 경제성을 고려해야 하므로 일정 규모 이상의 교량건설이 현실적으로 불가능하기 때문이다. 본 연구에서는 국내외 해상교량 관련 기준 및 절차 등에 대한 분석을 기초로 설계 기준 초안을 작성하여 해상교량 건설 관계자(항만협회, 건설교통부, 건설회사, 지차체 등)와 항만 이용자(도선사협회, 선박회사 등), 그리고 해양계열 대학 전문가의 의견을 충분히 수립하여 국내 실정에 적합한 해상교량 설계 기준안을 제시하고자 한다.

• Journal of the Korean Institute of Navigation
• /
• v.20 no.1
• /
• pp.1-10
• /
• 1996

The assesment of the safety of ship's transit in a curved narrow channel consists of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by ship's workload, and shiphandler's subjective evaluation. In this study, to examine the correlation between shiphandler's subjective evaluation and the maneuvering safety, the real-time and full-mission shiphandling simulator in the Korea Marine Training & Research Institute(KMTRI) was utilized. On the conning bridge of the shiphandling simulator, 50 experienced masters have conducted the modeled vessel of 60, 000 deadweight tonnage along the designed channel under 3 different environmental conditions. It was possible to assess and analyze theoretically the correlation between the shiphandler's subjective evaluation and maneuvering difficulty under each environmental condition by quantifying the data obtained from the tests. The results are as follows: $\circled1$ As the degree of maneuvering difficulty increases, the shiphandler's subjective evaluation increases in the designed channel under the designed environmental condition. $\circled2$ In the straight area, not the bend of the designed channel, maneuvering difficulty increases sharply under the environmental condition of current and wind coming from the stern.

• Journal of the Korean Institute of Navigation
• /
• v.19 no.4
• /
• pp.1-8
• /
• 1995

Although ship's draught information onboard is substantial for both the safety of navigation and the estimation of loaded cargoes, its accuracy depends, in conventional surveying method, on the skillfulness of observers and the condition of the sea surface round the vessel. To obtain more accurate information accessibly, measuring instruments with sophisticated sensors such as mechanical, electronic and ultrasonic transducers have been developed. However, they have still limitation in accuracy and in making up a system due to the complexity of processing signal. In this paper, we propose a new technique for analyzing ultrasonic pulse signal, in order to improve the measurement accuracy and simplify a remote sensing system of draught by ultrasonic waves. In this technique, pulse signal is translated into phase curve which is composed of the phase value defined in time domain. Then, the time interval between two signals different in waveform, is waveform, is analytically determined by calculating average time difference on phase curves. Also, analytical procedure can be carried out in real time with the successive five data sampled at T/4, for high speed digital processing with computer and A/D converter. This technique is useful for measuring draught under the influence of sea condition and for interfacing its data briefly to the integrated bridge system.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.207-210
• /
• 2005

This paper describes a design of several ship's emergency lighting system(SELS) that power factor is improved and power is controlled extensively, and techniques to control and monitor this system in remote distance by PC serial communication. The remote monitoring control system is composed of emergency power supply system (EPSS), half bridge(HB)inverter, fluorescent lamp(FL), microprocessor, multi communication interface. EPSS checks the voltage of the emergency backup battery in real time. In case that the voltage of 13[V] or less has been detected for 5[msec] or longer for 3 times in a row, charger circuit is connected for battery charging. Experimental works using proposed system confirm that speedy and stable power to be supplied when main power source cut-off, compared with conventional analog type, and input power up to 35.0[%] by adjusting of pulse frequency of the HB inverter.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.2 no.1
• /
• pp.35-45
• /
• 1996

The assesment of the safety of ship's transit in a curved narrow channel consists of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by ship's workload, and shiphandler's subjective evaluation. In this study to examine the correlation between shiphandler's subjective evaluation and the maneuvering risk, the real-time and full-mission shiphandling simulator in the Korea Marine Training & Research Institutes(KMTRI) was utilized. On the conning bridge of the shiphandling simulator, 50 experienced masters conducted the modeled vessel of 60,000 deadweight tonnage along the designed channel under 3 different environmental conditions. The findings were as follows : (1) The frequencies of stress levels, work difficulties, vessel controllability and overall workload of shiphandlers are similar irrespective of environmental conditions and they are able to be represented as shiphandler's subjective evaluation. (2) It s possible to assess and analyze theoretically the correlation between the shiphandler's subjective evaluation and maneuvering risk under each environmental condition by quantifying the data obtained from the test. The results are as follows : ① As the degree of maneuvering risk increases, the shiphandler's subjective evaluation increases sharply near the curvature area of the designed channel. ② In the area of the curvature of the designed channel, maneuvering risk sincreases sharply with the danger of running aground under the environmental condition of current and wind coming from the stern.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.11
• /
• pp.2419-2422
• /
• 2010

The current marine internal communication systems are usually composed of NMEA0183, NMEA2000, and MiTS protocols which are located on the physical layer based on RS-422, RS-485, CAN, and EtherNet. However, general vessel communication method have a weak point that must establish the extra private line. But, the power line communication has advantage over general vessel communication method as it uses AC220V/DC24V without changing line. Therefore, we will propose a new bridge based on the DC-PLC(power Line communication) technique which support the NMEA0183 protocol inside vessel network systems.

• Journal of the Society of Naval Architects of Korea
• /
• v.38 no.1
• /
• pp.108-115
• /
• 2001

The noise level of the navigation bridge as well as topside of the superstructure is dominated by the exhaust gas noise of the high-powered main engine and generator engine of special purpose vessels. In the case of the noise radiated from the top of the funnel. the exhaust pipe can be fitted with a silencer to reduce the propagated noise level. This paper is prepared based on an experimental performance test results of the silencers for generator-engine exhaust gas noise with consideration of air velocity. Two silencers were examined to check the performance of noise reduction in cases of air velocity 0m/s and 32m/s. In the sound reduction test, 400mm and 600mm diameter pipe ducts equipped with an axial fan were used as exhaust gas pipe system in the actual ship. The test procedure and results are presented in detail.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.3
• /
• pp.378-386
• /
• 2012

For reduction of the amount of CO2 emitted from ships, power generation characteristics of two power generation systems consisting of a high-efficiency permanent magnet synchronous generator and diode bridge rictifiers are discussed in this paper. One of the discussed systems has three-phase stator windings, and the other has two sets of three-phase (six-phase) stator windings to reduce pulsation in the electromagnetic torque and DC current. Experimental results reveal that the power generation efficiency of the system having six-phase stator windings is higher than that of the system having three-phase stator windings for a light load. The maximum power generation efficiency of the system having six-phase stator windings is almost the same as that of the system having three-phase stator windings. For the electromagnetic torque of the system having six-phase stator windings, the width of pulsation is about one-fifth compared to the system having three-phase stator windings.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.23 no.6
• /
• pp.422-428
• /
• 2011

Optimal reliability indices were found by optimizing life cycle cost(LCC) of pier type quay walls. Failure probability of pier and shore bridge were calculated by response surface method. Then, they were used to obtain recovery cost after damage. Costs for initial construction and maintenance were also considered in finding optimal reliability indices. Target reliability indices which may be used in reliability based design were suggested by numerical examples under seismic load and ship load.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.577-578
• /
• 2010

The current marine communication networks are usually composed of NMEA0183, NMEA2000, and MiTS protocols which are located on the physical layer based on RS-422, RS-485, CAN, and EtherNet. This paper proposes a new bridge based on the DC power line communication technique supported from the NMEA0183 to design inside marine systems.