• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.1
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• pp.31-38
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• 2016

In this paper, the deformation-energy curves of the plastic hinges and the vessel bow, which are the major energy dissipation mechanism of a pile protective structures, were estimated, and the parametric study was performed by using those curves to apply the simplified collision model which developed in the previous study. Considered parameters were the mass of slab, the number of piles, the mass of vessel and the collision speed. As results, the difference of energy dissipation mechanism of two pile types (filled and non-filled) were revealed, and the collision behaviors of the protective structures could be tuned by the control of the inertia mass of capping slab. Therefore the simplified collision model can be used in a primary design and optimal design.

• Journal of Ocean Engineering and Technology
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• v.15 no.3
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• pp.120-127
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• 2001

The potential pollution problems resulting from tanker collision necessitate the requirement for an effective structural design and the development of relevant safety regulations. During a few decades, the great effort has been made by the international Maritime Organization and the Administration, etc, to reduce oil spillage from collision accidents. However there is still a need for investigation in the light of structural evaluation method for the experiments and rational analysis, and design development for an operational purpose of ships. This study aims for investigating a complicated structural response of bow structures of simplified models and oil carriers for assessing the energy dissipation and crushing mechanics of the striking vessels through a methodology of the numerical analysis for the various models and its design changes. Through these study an optimal bow construction absorbing great portion of kinetic energy at the least penetration depth prior to reach to the cargo area and an effective location of collision bulkhead are investigated. In order to obtain a rational results in this study, three stages of collision simulation procedures have been performed step by step as follows; 1) 16 simplified ship models are used to investigate the structural response against bow collision with variation of primary and secondary members. Mass and speed are also varied in four conditions. 2) 21 models consisted of 5 sizes of the full scaled oil carriers are used to perform the collision simulation with the various sizes and deadweight delivered in a recent which are complied with SOLAS and MARPOL. 3) 36 models of 100l oil carrier are used to investigate the structural response and its influence to the collision bulkhead against bow collision in variation with location of collision bulkhead, primary members, framing system and colliding conditions, etc. By the first study using simplified models the response of the bow collision is synthetically evaluated for the parameters influencing to the absorbed energy, penetration depth and impact force, etc.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.119-126
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• 2001

The potential pollution problems resulting from tanker collision necessitate the requirement for an effective structural design and the development of relevant safety regulation. During a few decades, the great effort has been made by International Maritime Organization and the Administration, etc, to reduce oil spillage from collision accidents. However there is still a need for investigation in the light of structural evaluation method for the experiments and rational analysis, and design development for an operational purpose of ships. This study is aimed at investigating a complicated structural response of bow structures of oil carriers for assessing the energy dissipation and crushing mechanics of striking vessel through a methodology of the numerical analysts for the various models and its design changes. Through this study an optimal bow construction absorbing great portion of kinetic energy in the least penetration depth prior to reach to the cargo area and an effective location of collision bulkhead are investigated. In order to obtain a rational results in this study, three stages of response analysis procedures are performed as follows; 1). 16 simplified ship models are used to investigate the structural response against bow collision with variation of primary and secondary members. Mass and speed are also varied in two conditions. 2). 21 models conisted of 5 size of full scaled oil carriers are used to perform the collision simulation with the various sizes and deadweight delivered in a recent which are complied with SOLAS and MARPOL. 3). 36 models of 100k oil carrier are used to investigate the structural response and its influence to the collision bulkhead against bow collision in variation with location of collision bulkhead, primary mombers, framing system and colliding conditions, etc.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2005.03a
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• pp.7-7
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• 2005

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.323-330
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• 2008

The ship collision analysis of steel pile group as protection system of bridge in navigable waterways was performed to analyze the structural characteristics of protective structure during ship collision. The analysis encompassed finite element modeling of ship and pile, modeling of material non-linearity, hard impact analysis, displacement-based analysis and soft impact analysis for collision scenarios. Through the analysis of hard impact with a rigid wall, impact load for each collision type of ship bow was estimated. In the displacement-based analysis the estimate of energy which protection system can absorb within its maximum horizontal clearance so as to secure bridge pier from vessel contact during collision was performed. Soft impact analysis for various collision scenarios was conducted and the collision behaviors of vessel and pile-supported protection system were reviewed for the design of protection system. The understanding of the energy dissipation mechanism of pile supported structure and colliding vessel would give us the optimized design of protective structure.

• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.325-332
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• 2020

This study aimed to identify the difference of scapular movements between tennis players with and without shoulder impingement syndrome(SIS) and to verify the effect of kinesiology taping applied to scapular. A total of 15 players were categorized in SIS group(n=7) and control(CON) group(n=8). The scapular movements evaluated using 3-dimensional motion analysis in the 5 events of the flat first serve before and after the application of taping. The male of SIS group(-7.31±1.19° and -5.28±1.08°, respectively) had tilted scapular more anteriorly compared to CON group(-0.98±5.38° and -0.44±3.52°, respectively) at the maximally humeral external rotation and the impact(Z=-2.309, p=.021 and Z=-2.309, p=.021, respectively). The scapular(-8.11±2.57°) of female in SIS group tilted more anteriorly than that of CON(-0.97±3.31°) group at the maximally humeral external rotation(Z=-2.121, p=.034). But the scapular movements had no statistical differences between before and after the application of taping.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.138-138
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• 2020

전세계적으로 자율운항선박 기술개발이 활발하게 이루어지고 있으며, IMO(국제해사기구)에서는 자율운항선박 도입을 위한 제도적 측면에서 검토 중이다. 우리나라도 해수부-산업부 공동으로 자율운항선박 기술개발사업을 진행 중이며, 2025년까지 자율화등급 3수준의 기술개발을 목표로 한다. 본 연구는 자율운항선박 항해에 기초가 될 충돌회피 시점을 도출하고자 한다. 이를 위해 우리나라 연안의 해상교통조사 자료를 이용하여 선박운항자의 피항시점(CPA, TCPA, 위험도, 이격거리, 선수방향차이 등)을 파악하고자 한다. 피항시점은 자율운항시스템의 기초학습자료로 이용할 수 있을 것으로 예상된다.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.36-42
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• 2005

Purpose: To investigate the arthroscopic findings, and to evaluate the clinical outcomes of the treatment of posterior internal impingement of the shoulder in baseball players. Materials and Methods: We followed up 5 cases who were diagnosed as posterior internal impingement for the mean 15 months. All of the cases complained of the pain in the posterior shoulder at late cocking, and were positive in the relocation test added by hyper-horizontal abduction at $120^{\circ}$ abduction of the arm. We sutured posterior labral tear and SLAP lesion arthroscopically, and conducted debridement for rotator cuff. Three cases were performed of anterior capsular plication and the other two were performed of thermal capsular shrinkage. Pain, range of motion, and level of return to sports activity were assessed for the results. Results: As to the arthroscopic findings, all the five cases showed the fraying in posterosuperior labrum, and two of them was accompanied with the flap tear in posterosuperior labrum and the other one was accompanied with type 2 SLAP lesion. All the cases showed the fraying in supraspinatus, and one case showed partial tear. Meanwhile, in all the cases, the rotator cuff was impinged to the labrum at $90^{\circ}{\sim}120^{\circ}$ of abduction and external rotation. As to the postoperative results, all the cases did not complain of pain or instability while pitching, and the competition was recovered to be the mean 88%($80{\sim}100%$) of that before the injury. Conclusion: Definite diagnosis for the posterior internal impingement would be possible through arthroscopic examination. Favorable outcomes could be obtained with capsular plication or shrinkage for anterior microinstability and stretching exercise for posterior capsule tightness inducing the internal impingement.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.40-46
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• 2017

Shipping activities have become possible in the Arctic Ocean due to melting ice by global warming. An increasing number of vessels are passing through the Arctic Ocean consequently bringing concerns of ship-iceberg collisions. Thus, most classification societies have implemented regulations to determine requirements for ice strengthening in ship structures. This paper presents the simulation results of an ice-strengthened polar class ship after an iceberg collision. The ice-strengthened polar class ship was created in accordance with the Unified Requirements for a Polar-Ship (IACS URI). An elastic-perfect plastic ice model was adopted for this simulation with a spherical shape. A Tsai-Wu yield surface was also used for the ice model. Collision simulations were conducted under the commercial code LS-DYNA 971. Hull deformations on the ice-strengthened foreship structure and collision interaction forces have been analysed in this paper. A normal-strength ship structure in an iceberg collision was also simulated to present comparison results. Distinct differences in structural strength against ice impact forces were shown between the ice-strengthened and normal-strength ship structures in the simulation results. About 1.8 m depth of hull deformation was found on the normal ship, whereas 1.0 m depth of hull deformation was left on the ice-strengthened polar class ship.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.1
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• pp.103-117
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• 1995

A design-oriented method for analysis of the structural damage due to ship collisions is developed by using the idealized structural unit method(ISUM). The method takes into account yielding, crushing, rupture, the coupling effects between local and global failure of the structure, the influence of strain-rate sensitivity and the gap/contact conditions. The method is verified by a comparison of experimetal and numerical results obtained from test models of double-skin plated structures in collision/grounding situations with the present solutions. As an illustrative example, the method has been used for analyses of a side collision of a double-hull tanker. Several factors affecting ship collision response. namely the collision speed and the scantlings/arrangements of strength members, are discussed.