• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.1 s.20
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• pp.35-40
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• 2004

Ship can not sail without water. Ships sail along different routes with different natural conditions. Thus ships sailing at different sea areas have their respective characteristics. The northern sea area and the southern one of China have different characteristics, that is to song, the sea in the northern area is shallow and that in the southern area is deep, Chinese ships developed into different types in order to adapt to this.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.2
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• pp.209-220
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• 1997

DBS offers actual services to mass-media and communication system of very broad region in information society. Especially, the DBS is the only system to access TV broadcasting service on a sailing ship. But the ship's DBS receiver is required a complex antenna tracking system because ships are under complex moving such as pitch, roll, and yaw etc. This study is motivated to develop a tracking antenna system to receive the koreasat on small silo ship. Therefore, this system is researched to small size, light weight, simple operation, and low cost of the product. The mount structure have been a compact size and easy operation to the Az/El 2-axis type which is operated by step motor. And it is very useful on a ship in the around sea of korean peninsula. The antenna has a plate type of micro-strip array, and is a domestic production. The vibration sensor is selected to gyro sensor of ultra-sonic rate type for ship's moving control. Tracking method is used the step-tracking algorithm, and the ship's moving compensation is adapted to the closed loop control method by ship's moving detection of gyro sensor. Tracking test is operated by the ship's moving simulator, we examined the actual receiving state on sailing shipboard in the near sea of korean peninsular.

• Structural Engineering and Mechanics
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• v.49 no.3
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• pp.311-327
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• 2014

The safety relating to leakage of water and pitch instability of ship chambers of the full balanced hoist vertical shiplifts has been the focus of adoption of the type of vertical shiplifts. This paper aims to remove the doubts through theoretical and engineering researches. The leakage and pitch stability of ship chambers of full balanced hoist vertical ship lifts are investigated on the basis of theoretical analysis and exploration of engineering measures. Regarding the issue of leakage of ship chambers, a mathematical model on leaking process is built and corresponding formula and coping measures are obtained which can be applied in control program of ship lifts by linking with monitoring. The concept of safety grade is put forward to seek the best technical and economic index and the corresponding technical measures are for different grades of ship lift is suggested. For the issue of pitch instability, a methodology of combining theoretical deduction and summary of achievements of design and operation of the type of the full balanced hoist shiplifts is adopted, and the formula for design about pitch stability of ship chambers is derived.

• Journal of Korean Port Research
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• v.5 no.2
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• pp.39-63
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• 1991

A PC-based ship maneuvering simulator was developed which was configured in a high performance IBM PC compatible i486 and i286 computer with a TMS 340 graphic signal processor and 10 MBPS Ethernet Cards. A real-time ship maneuvering simulation program was developed which includes computer generated imagery (CGI) for bird's eye view type and perspective view type. The simulator H/W was designed and manufactured and S/W for interface of various navigation equipments was made Especially, programs for output, analysis, and assessment of simulations results were developed. Communications between PC's are made by using Ethernet bus type LAN system. Simulations could be performed under various environments (current, wind, wave etc.) using data base of harbors and ships. This system can be used for various purposes such as crew's training, harbor and waterway design, and assessment of ship maneuverability in harbor.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.6
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• pp.439-446
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• 2022

Efforts to reduce carbon dioxide(CO₂) emissions are being carried out due to climate environmental problems. Eco-friendly ships are also being developed, and various energy saving measures have been developed and applied. In ships, researches have been conducted in various fields such as electric propulsion system and energy saving devices. In addition, the development of ships using various renewable energy, such as kite using wind power and wind power generation, has been carried out. This paper proposes a plan to use renewable energy for ships by applying wave generators to small ships. In 2016, 130 small domestic ships drifted by sea due to discharge of starting storage batteries, and discharge cases accounted for the largest portion of the causes of domestic ship accidents. This is due to the excessive use of storage batteries for starting the main engine by departing in a weak storage battery state for small ships. Accordingly, two type wave power generators - opened flow wave power generator and enclosed vibrator type wave power generator - are developed for charging a starting storage battery when the ships are stationary at sea or port. Opened flow wave power generator utilizes the flow of fluid in the ship by using wave induced ship motion. Enclosed vibrator type wave power generator utilizes the pendulum kinetic energy located in a ship due to wave induced ship motion.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.250-253
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• 2011

The cruise industry is one of the world's fastest growing device industry which is structural construction coasts are expensive. Cruise out-fittings are thirty times compare with general large vessels. According to the characteristics of materials or equipments, most equipments are imported from europe. At present domestic shipbuilding industries and minor enterprises have a hard times therefore enhancing technology for the cruise industry could be infused vitality on the industries. If domestic small and midium industries have high technology for the cruise ship, domestic small and midium industries can have global competitiveness compare with european equipment suppliers which has small-scale and high technology. Therefore on this study, cruise ship's new equipment development and a study for the performance assessment and classification type approval certificate was carried out.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.849-854
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• 2013

Many researches on green ship with increasing on economics, efficiency and convenience have been carried out consistently. One of them is development of diesel engines with electronic control. While small duty one for automobiles had been adopted mainly already, disseminating heavy duty one for ships has trouble due to safety and reliability. In order to solve these problem in this study, performance of electronic control and cam type engine installed in parallel on training ship HANBADA of korea maritime university was analyzed and compared. It is certain that specific fuel oil consumption of the electronic control type is lower than cam type and excellent at lower engine load, especially. And the electronic control type shows more effective characteristic at sea trial on specific fuel oil consumption.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.5
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• pp.314-321
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• 2021

In the existing whole ship analysis, topside was modeled as mass element. However recently, the topside is modeled as beam element due to the owner's requirement to improve the maturity of the whole ship FE model. To follow the owner'srequirement, detailed information for topside drawing and modeling, which may delay analysis schedule, is needed. However, it is hard to respond effectively to this matter due to the lack of study on the topside from the hull perspective. Therefore in this study, the effect of the topside on the hull is investigated when the topside is modeled as a mass element or beam element respectively. In addition, the interface modeling method is analyzed to verify modeling method used in the existing whole ship analysis. The results indicate that the interface and topside modeling method used in existing whole ship analysis are appropriate. This conclusion will be the technical basis for responding to owner's requirement about the topside modeling method.

• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1548-1554
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• 2001

Flow patterns and dynamic properties of two-stage Weis-Fogh type ship propulsion mechanism are studied by a discrete vortex method. To study mutual interference between two wings, two cases are con sidered - wing motions with the same and reverse phases. The predicted flow patterns correspond to the available flow visualization results. Time histories of thrust and drag coefficients are also calculated, and the interference between the two wings are numerically clarified.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.149-154
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• 2001

Ship owners are demanding quieter vessels since crews have become more sensitive to their acoustic environment. Accordingly, designers of shipyards need to respond intelligently to the challenging requirements of delivering a quiet vessel. In early design stage, to predict shipboard noise the statistical approach is preferred to other methods because of simplicity. However, since the noise characteristics of the ships vary continuously with the environments, it is necessary to update the prediction formula with data base management system. This paper describes the feature of database program with the prediction method. Database management programs with GUI, are applied to Intranet system that is accessible by any users. Statistical approach to the prediction of A-weighted noise level in ship cabins, based on multiple regression analysis, is conducted. The noise levels in ship cabins are mainly affected by the parameters of the deadweight, the type of ship, the relative location of engines and cabins, the type of deckhouse, etc. As a result of verification, the formulas ensure the accuracy of 3 ㏈ in 83 % of cabins.