• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1812-1821
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• 2016

The purpose of this study is to survey input data error of ship automatic identification system (AIS) and suggest its improvement. The effects of AIS were observed. Input data error of AIS was investigated by dividing it into dynamic data, static data by targeting actual ships and its improvement method was suggested. The findings are as follows. Looking into accidents before and after AIS is enforced to install on the ship, total collision were decreased after AIS installed. Static data error of AIS took place mainly in the case that ship name, call sign, MMSI, IMO number, ship type, location of antenna (ship length and width) were wrongly input or those data were not input initially. Dynamic data error of AIS was represented by input error of ship's heading. As errors of voyage related data take place as well, confusion is made in sailing or ship condition. Counter measures against the above are as follows. First, reliability of AIS data information should be improved. Second, incessant concern and management should be made on the navigation officers.

• Proceedings of KOSOMES biannual meeting
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• 2003.05a
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• pp.31-40
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• 2003

There are winds and waves in the sea, and they are changed frequently in accordance with the weather. By analyzing them which have the closest relation to the ship's safe voyage. evaluating the seakeeping performance and then taking a proper action, navigators should carry out safe navigation on the sea. A ship in seaways suffers continuous disturbances by irregular waves, and ship motions with irregular waves cannot be easily described as a system model which is adequate to a control system. But, in general, for seakeeping analysis, ship motions in irregular seas can be estimated by the superposition of the motion responses in regular wave components of the sea spectrum. After comparing and analyzing the winds and waves in major sea areas, this paper evaluates the navigational safety of ships on the Korean coast with potential dangerous seakeeping performance using the weather information provided by land. The conclusion is as follows : (1) It is possible that the safety of ships could be secured more accurately by evaluating the seakeeping performance of ships. (2) When the weather is bad, the departure of ships could be controlled by evaluating the navigational safety of ships. (3) When a ship is placed in commission in any area, this evaluation could be used to decide the type and size of ship in use.

• Journal of Navigation and Port Research
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• v.36 no.7
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• pp.571-575
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• 2012

Berthing and unberthing maneuver is essential work for marine pilots and securing the safety against risks during the maneuver is more important than anything else. Moreover, the maneuvering environment in ports and harbors has changed rapidly and got worse due to development of a new port, the advent of a new type or large-sized ship, and the rapid increase in harbor traffic. As one of measures taken to cope with such changes in the maneuvering environment and for each pilot to improve his own maneuvering ability, this paper developed laptop-based ship-handling simulator which is readily available anytime and anywhere. This paper is to develop a conning display for ship's maneuvering and electronic chart based display widely used nowadays to represent a model ship's movement. The displays were arranged appropriately considering pilot age, easy handling by mouse, using a maximum screen, proper arrangement of rudder, engine, thruster, tug etc and representation of information. Up to now thirteen (13) model ships were developed based on real-ship, whose mathematical model is Japanese MMG & pilots' low speed maneuver.

• Journal of Ocean Engineering and Technology
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• v.17 no.5 s.54
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• pp.88-94
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• 2003

A series of tests of 5 model ships, selected from a data survey of 10 Gross Tonnage actual fishing boats, were performed in two circulating water channels (Chosun University in Korea and WJFEL in Japan), in order to develop the basic hull form of a 25 knots-class fishing boat. Resistance tests, trim and sinkage measurements and wave pattern observations etc., were included in each I1wdel test, and the model test results were compared and analyzed. The result was as follows: P-4 hull form ship changed into Deep V type bow is the best hull form with good performance, especially with regard to ship's resistance efficiency.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.253-259
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• 2018

In February 2014, the rudder upper stock and the nut of a passenger ship were released and an accident occurred. That accident occurred because the steering gear of passenger ships that was intended to move many passengers. The accidents due to steering gear was zero according to 2010-2016 statistics. There is no rules prevent loosening of the upper rudder nut in "Ship Safety Act" and "Structural standard of steel ship". Since the accident, the Korea register has been revised to the joining method in Part 5 Chapter 7 of the rules in the classification of steel ships. In the field survey of 12 passenger ships operating on Mokpo and surrounding islands, the welding method was applied in the cases as the fastening method. The fastening type was equipped with two C-type structures. It was structured to be difficult to access. The NAS 3350 test was conducted to investigate ways to prevent homologous accident considering the characteristic of passenger ships that need to lift or unload rides once a year.

• Structural Engineering and Mechanics
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• v.42 no.4
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• pp.507-530
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• 2012

Age-related problems especially corrosion and fatigue are normally suffered by weatherworn ships and aging offshore structures. The effect of corrosion is one of the important factors in the Common Structural Rule (CSR) guideline of the ship design based on a 20 or 25 years design life. The aim of this research is the clarification of the corrosion effect on ultimate strength of stiffened panels on various types of double hull oil tankers. In the case of ships, corrosion is a phenomenon caused by the ambient environment and it has different characteristics depending on the parts involved. Extensive research considering these characteristic have already done by previous researchers. Based on this data, the ultimate strength behavior of stiffened panels for four double hull oil tankers such as VLCC, Suezmax, Aframax, and Panamax classes are compared and analyzed. By considering hogging and sagging bending moments, the stiffened panels of the deck, inner bottom and outer bottom located far away from neutral axis of ship are assessed. The results of this paper will be useful in evaluating the ultimate strength of an oil tanker subjected to corrosion. These results will be an informative example to check the effect of ultimate strength of a stiffened panel according to corrosion addition from CSR for a given type of ship.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.4
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• pp.87-96
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• 2006

A ship collision analysis by finite element method is performed considering the effects of mass and speed of ship and material and shape of structures to analyze the dynamic characteristics by ship collision. From this analysis, collision load-time history and damage of ship and structures are obtained. In this study, results of finite element analysis are compared with previous studies in USA, Japan and some countries of Europe. Dynamic characteristics are different from each other according to interaction between ship and structures. It seems that there are lots of factor to have effects on the ship-structures interaction. Because little information is available on the behavior of the inelastic deformation of materials and structures during the type of dynamic impacts associated with vessel impact, assumptions based on experience and sound engineering practice should be substituted. Therefore more researches on the interaction between ship and structures are required.

• Journal of the Korean Institute of Navigation
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• v.22 no.1
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• pp.63-77
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• 1998

It is one of the most important factors Seafarers Ducation Quality Assurance and Management in Higher Maritime Educational Institution. The educational process and result of Higher Maritime Educational Institution should be evaluated according to the 1995 Amendments to the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers(STCW), 1978. Actually above-mentioned evaluation is deemed to make foundation in order to enhance the efficiency of shipboard education by surveying the satisfaction of shipboard training for nautical part cadets by the group. In this paper, we carried out the questionnaire survey to study satisfactory value and the reason of dissatisfaction of 113 cadets being trained on board the Training Ship in Maritime College of Korea Maritime University(K. M. U.). The results were calculated by frequency and percentage ; the significance of difference among Department groups like Maritime Transportation Science, Maritime Police and Ship Operating Systems Engineering was analysed by $X^2$ inspection. The major results of above analysis were as follows : First training chance for dadets was very little for being overflowed on board the training ship of the K. M. U. Second, special type of Training Ship HANBADA and HANNARA made the adaptability to merchant vessel's handling restricted. Third, cadets could not manage ratings directly, therefore the education in regard to seafaring management was limited to the theoretical instruction which leads to the low level of satisfaction. And lastly, low value of satisfaction for Drydocking Education in Shipyard was caused by cadet's leaving the Training Ship on account of the safety problems including ship and cadets.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.11 s.104
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• pp.1223-1231
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• 2005

Recently, the issue of ship nitration due to the large scale, high speed and lightweight of ship is emerging. For pleasantness in the cabin, shipbuilders are asked for strict vibration criteria and the degree of nitration level at a deckhouse became an important condition for taking order from customers. This study proposes a new optimization framework that is NASTRAN external call type optimization method (OptShip) and applies to an optimum design to decrease the nitration level of a deckhouse. The merits of this method are capable of using of global searching method and selecting of various objective function and design variables. The global optimization algorithms used here are random tabu search method which has fast converging speed and searches various size domains and genetic algorithm which searches multi-point solutions and has a good search capability in a complex space. By adapting OptShip to full-scale model, the validity of the suggested method was investigated.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.871-879
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• 2011

The internal deck structure of turtle ship has been investigated with the following approach manner. Firstly the 5 species of turtle ship are identified by examining the characteristics of 5 turtle ships revealed by the librarian or paintings. Secondly the centers of gravity and buoyancy for each type are calculated to evaluate the turtle ship's buoyancy stability. Thirdly the optimal deck structures for 5 turtle ships are additionally assessed from the viewpoint of the interoperability of soldier's missions to get more meaningful conclusion. From the results obtained by the well refined analyses above, one can identify that Changjeguyseon and Lee Chung Mu Gong descendent family's turtle ship possess one layer deck, and the tongjeyoung and jwasuyoung turtle ship consist of 1 and half story deck, and the one disclosed by Yoon has 2 story structure.