간행물

Journal of Korean Navigation and Port Reserch KCI 등재 한국항해항만학회지

권호리스트/논문검색
이 간행물 논문 검색

권호

Vol.34 No.4 (2010년 6월) 6

1.
2010.06 서비스 종료(열람 제한)
The national VTS was launched in 1993, and has adopted a harbour-oriented control method which is unable to consider enough characteristics of its work. However, for the past 17 years, the characteristics has changed due to increased amount of vessels. Up to now the domestic Vessel Traffic Service has adopted harbour-oriented control method which is unable to consider enough characteristics of its work. However, developed countries have carried out waters-oriented control method, according to the using areas of ships, to be well considered the characteristics of control for increasing efficiency of it. Especially, VTS of Daesan, Pyeongtaek and Inchon harbour can have confusions of control because of overlapped service areas of it. Therefore, in this paper suggested a new Sector Division that the relevants waters is divided into 3 operational Regions and these are divided into nine sectors again, for the purpose of improving the efficiency and the concentration of VTS.
2.
2010.06 서비스 종료(열람 제한)
The Mobile Harbor(MH) is a new transportation platform that can load and unload containers to and from very large container ships in the sea. This loading and unloading by crane can be performed with only very small movements of the MH in waves because MH is operated outside of the harbor. For this reason, an anti-rolling tank(ART) and an active mass driving system(AMD) were designed to reduce MH's roll motion, especially at the natural frequency of MH. In the conceptual design stage, it is difficult to confirm the design result of theses anti-rolling devices without modeling and simulation tools. Therefore, the coupled MH and anti-rolling devices' dynamic equations in waves were derived and a simulation program that can analyze the roll reduction performance in various conditions, such as sea state, wave direction, and so on, was developed. The coupled equations are constructed as an eight degrees of freedom (DOF) motion that consists of MH's six DOF dynamics and the ART's and AMD's control variables. In order to conveniently include the ART's and AMD's control dynamics in the time domain, MH's radiated wave force was described by an impulse response function derived by the damping coefficient obtained in the frequency domain, and wave exciting forces such as Froude-Krylov force and diffraction force and nonlinear buoyancy were calculated at every simulation time interval. Finally, the roll reduction performances of the designed anti-rolling devices were successfully assessed in the various loading and wave conditions by using a developed simulation program.
3.
2010.06 서비스 종료(열람 제한)
A new concept of ocean transport system, called mobile harbor, was introduced as a feasibility study in Korea in 2009. Target of the mobile harbor is a short distance transport of containers with or without cargo handling cranes. Although the mobile harbor project has a lot of topics to deal with, this paper is to focus on only ship-to-ship stabilized mooring, which plays a key role in cargo handling. The ship-to-ship stabilized mooring system was developed and installed on board a barge of LOA 32m and breadth 12m. The dockside tests as sea test were carried out so as to ascertain whether the systems can work well to control the barge’s motion. The results of dockside test showed that the heave motion of the barge's motion can be reduced by more than 45%.
4.
2010.06 서비스 종료(열람 제한)
The purpose of this study was to create a cyber-training & education program in response to the needs of skippers and crews operating tug-barges within Korean coastal waters and the rapid changers in this industry. Skippers and crews are inclined to operate tug-barges on the basis of experience rather than information. It is not easy to provide useful information whenever they want or to drill them in safety management skills, because of their passive attitude toward education and the few opportunities that exist. In order to increase educational opportunities, efficiency and motivation, the authors have developed this program which consists of a 'tug bridge resource management module, risk perception training module, accident case module, operating module and navigation module', and are hoping that this program will enhance and strengthen all tug-barge operations. We are also putting all our energies into designing up to date animation programs and developing new scenarios concerning the method of evaluation and certification distribution.
5.
2010.06 서비스 종료(열람 제한)
The residential comfort and safety on ship are more focused than ever, in accordance with the increase of the crews' onboard time and interest in cruiser sailing. To grasp the safety characteristics on ships against various scenarios of evacuations, this study performed experiments and simulations for the evacuation times on a training ship. Through the experiments, the average walking speed is 3.0m/s on 100% visibility, and 1.2m/s on 8% visibility, but the speeds go down 1.3m/s and 0.7m/s, respectively, when obstacles are happened without any previous notification. From the simulation, it is clearly reconfirmed that the worse visibility and many people make evacuation time comparatively longer. And unlike the common expectation of the effect of emergency announcement, the difference of evacuation times between cases of announcement and non-announcement is negligible on this study. From the survey after experiments, it is known that experiment participants feel unsafe and fear when the evacuation routes are longer in bad visible condition, even if they know the perfect evacuation route. And the survey results also show that the evacuees give more careful consideration to make a evacuation route decision under bad visibility.
6.
2010.06 서비스 종료(열람 제한)
In this paper, the EM wave absorber was developed for the 94-GHz detecting radar system. To analysis an EM wave absorber in millimeter wave band, we fabricated three absorber samples using carbon black and titanium dioxide and permalloy with chlorinated polyethylene. After measuring the complex relative permittivity, the absorption characteristics are simulated by 1D FDTD according to different thicknesses of less than 1.0 mm. Then, the EM wave absorber was fabricated based on the FDTD simulation. As a result, the measured results agreed well with the simulated ones, and the developed EM wave absorber with a thickness of 0.7 mm had the desired absorption characteristics of more than 14 dB in the frequency range of the 94-GHz band.