• Journal of the Society of Naval Architects of Korea
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• v.31 no.1
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• pp.50-62
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• 1994

This paper presents the results of a comparative analysis of the model test results to investigate the effect of bulbous bow installed on a large full form ship to the ship resistance performance. Seven parameters related to the shape of bulbous bow were selected and varied systematically to inquire their effects experimentally. A total number of twenty-three ship models with different bulbous bow were manufactured, and resistance tests. flow visualization test, and wave profile measurement were carried out for each model. For the comparative analysis between the various bulb forms and their model test results, bulbous bow forms are classified into nine groups according to their form characteristics. From the analysis of the trend of the resistance components, it was verified that form resistance has dominant effect on the total resistance of a slow full form ship. The model test and its statistical analysis showed that the direction of streamlines around bulbous bow has close relationship with resistance components. especially with form resistance

• Journal of the Society of Naval Architects of Korea
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• v.33 no.1
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• pp.54-64
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• 1996

It seems that blowing air bubble out of the bulb surface of a ship of flat bottom will reduce the frictional resistance, since wetted area of the hull surface is reduced owing to air bubble staying close to the surface. To as certain this concept, at first, the limiting streamlines around the bow was observed, and local distribution of pressure and shear stress, due to the change of air-blowing position, air supply pressure, and the model speed, was investigated. It was found that the local friction was reduced near the bulb and air-bubble formations also play an important role as a drag component. This paper can be considered as a preliminary study on the drag reduction of conventional ships by the micro-bubble injection.

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.28-35
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• 2000

In this paper a complicated structural behavior in collision and its effect of energy transmission to the collision bulkhead was examined through a methodology of the numerical simulation to obtain a ideal bow construction and a location of collision bulkhead against heat on collision. At present the bow structure is normally designed in consideration of its specific structural arrangement and internal and external loads in these areas such as hydrostatic and dynamic pressure wave impact and bottom slamming in accordance with the Classification rules and the specific location of collision bulkhead by SOLAS requirement. By these studies the behavior of the bow collapse due to collision was synthetically evaluated for the different size of tankers and its operational speed limits and by the results of these simulation it provides the optimal design concept for the bow construction to prevent the subsequent plastic deformation onto or near to the collision bulkhead boundary and to determine the rational location of collision bulkhead.

• Journal of Korean Port Research
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• v.14 no.2
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• pp.219-231
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• 2000

In this paper a complicated structural behavior in collision and its effects of energy translation to the collision bulkhead was examined through a methodology of the numerical simulation to obtain a ideal bow construction and a location of collision bulkhead against head on collision. In the present the bow structure is normally designed in consideration of its specific structural arrangements and internal and external loads in these area such as hydrostatic and dynamic pressure, wave impact and bottom slamming in accordance with the Classification rules, and the specific location of collision bulkhead by SOLAS requirement. By these studies the behavior of the bow collapse due to collision was synthetically evaluated for the different size of tankers and its operational speed limits, and by the results of these simulation it provides the optimal design concept for the bow construction to prevent the subsequent plastic deformation onto or near to the collision bulkhead boundary and to determine the rational location of collision bulkhead.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.560-565
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• 2016

최근 대형 컨테이너선의 개발이 지속적으로 이루어짐에 따라 슬래밍에 의한 선수 및 선미의 구조안정성 문제가 대두되고 있지만 설계 단계에서 슬래밍에 대해 고려하기에는 현상의 복잡성으로 인해 어려움이 많았다. 이를 위해 KRISO에서 시행된 WILS JIP의 선수 단면 형상 및 선미 단면인 쐐기 형상으로 격자를 생성하여 EDISON CFD 다상유동 해석자를 통해 수치해석을 시도하였다. 기존 방식과 달리 계산 시간 절감을 위하여 격자 변형 기법을 적용하지 않고 모형 시험결과를 기반으로 한 유입류 조건을 설정하여 입수 충격 문제를 해석해보았다. 그 결과, 선미 형상의 경우 선행연구와 유사하게 실험 결과에 근접한 유체 충격력을 정량적으로 얻어낼 수 있었다. 선수 형상의 경우에서는 구상 선수로 인해 파생되는 센서 위치별 충격력의 변화를 확인할 수 있었으며, 실제 유동에 가까운 유동 형상과 슬래밍에 의한 충격력을 개략적으로 구할 수 있었다.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.04a
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• pp.195-204
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• 2000

In this paper a complicated structural behavior in collision and its effect of energy translation to the collision bulkhead was examined through a methodology of the numerical simulation to obtain a ideal bow construction and a location of collision bulkhead against head on collision. In the present the bow structure is normally designed in consideration of its specific structural arrangements and internal and external loads in these area such as hydrostatic and dynamic pressure, wave impact and bottom slamming in accordance with the Classification rules, and the specific location of collision bulkhead by SOLAS requirement. By these studies the behavior of the bow collapse due to collision was synthetically evaluated for the different size of tankers and its operational speed limits, and by the result of these simulation it provides the optimal design concept for the low construction to prevent the subsequent plastic deformation onto or near to the collision bulkhead boundary and to determine the rational location of collision bulkhead.

• Journal of Industrial Convergence
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• v.19 no.4
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• pp.17-21
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• 2021

Recently, in the field of sports, the use of data in conducting games, planning seasons, and operating teams has increased significantly. Also, in order to develop better players, it has become necessary to use data to accurately analyze their performance. Therefore, in this study, various data about rookie players was collected and pre-processed in order to analyze and visualize their performance. Additionally, an analysis was conducted to determine at least how many opportunities should be given to foster rookie players. Then, a data analysis method was presented for nurturing athletes by using data in the field of sports. It is expected that this study will contribute to fostering rookie players by utilizing data.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.40-44
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• 2001

선형개발에 대한 연구는 주로 대형선박을 기준으로 Bezier, B-spline 그리고 NURBS와 같은 합성곡선생성기법을 이용하여 일반 곡선기법으로는 표현하기 힘든 구상선수나 굴곡이 심한 선미 등을 표현하고 검증하는 것으로 이루어지고 있다. 하지만, 전체 선박의 70%를 차지하고 있는 중소형 어선의 선형에 대한 연구나 기술적인 보고는 상대적으로 미흡한 실정이다. 본 연구에서는 기존의 라운드타입에서 챠인 및 신챠인타입으로 변화해 가는 중소형 어선의 선형을 NURBS기법을 이용하여 표현하고, 전산화하는 프로그램을 개발하였다.

• Bulletin of the Society of Naval Architects of Korea
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• v.5 no.2
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• pp.27-33
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• 1968

The resistance decreasing effects of a bulbous bow have been investigated with the model test results of the Korean standard type 10,000GT cargo vessel equipped with several different sized bulbous bows. The best bulbous bow for the design is 3.66% bulb which decrease the residual resitance 5%. The new hull combined with a bulbous bow have to be designed in other to get more effects.

• The Journal of Bigdata
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• v.7 no.1
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• pp.49-61
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• 2022

In sports, the proportion of data analysis in team management such as team strategy planning and marketing is increasing. In KBO(Korea Baseball Organization) league, in particular, plans such as recruiting players and fostering players are established to devise team strategies for the next year, such as FA and trade, at the end of a season. For these reasons, it is very important to predict players' performance for the next year. In this study, the target was limited to only the batter and tried to find out how to predict whether the performance of the next year will improve. As a standard record for rising and falling, OPS(On-Base Plus Slugging), which is easy to calculate and has a high relationship with team score, was used. In this study, 40 years of regular season data from 1982 to 2021 were used as data, and 11 machine learning classification models were used as experimental methods. Predicting the rise and fall of OPS, RBF SVM, Neural Net, Gaussian Process, and AdaBoost were more accurate than other classification models, and age did not significantly affect accuracy.