• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6A
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• pp.425-433
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• 2011

In this study, in order to investigate the wave-induced buoyancy effects, experimental studies were conducted on pontoon-type floating structures. A series of small-scale tests with various wave cases were performed on the pontoon models. A total of four small-scale pontoon models with different lateral shapes and bottom details were fabricated and tested under the five different wave cases. Six hydraulic pressure gauges were attached to the bottom surfaces of the pontoon models and the wave-induced hydraulic pressure was measured during the tests. Finally, hydraulic pressures subjected to the bottoms of the pontoon models were compared with each other. As the results of this study, it was found that whereas the waffled bottom shape hardly influenced the wave-induced hydraulic pressure, the hybrid lateral shape significantly influenced the wave-induced hydraulic pressure subjected on the bottoms of floating structures. The air gap effects of the hybrid shape contribute to decreasing the wave-induced hydraulic pressure due to absorption of wave impact energy. Compared with box type, the hydraulic pressures of the hybrid type were about 83% at the bow, 74% at the middle, and 53% at the stern.

• 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 Korean Orthopaedic Association
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• v.54 no.3
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• pp.287-291
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• 2019

Although acute traumatic fractures of the clavicle are relatively common, stress fractures of the proximal clavicle are extremely rare. Stress fractures of the clavicle have often been reported after a radical neck dissection or radiation but rarely occur during excessive repetitive exercise in professional athletes. The authors report a case of a stress fracture of the proximal clavicle during exercise in a young man with no specific preceding factors, which has not been reported in the Korean literature.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.2
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• pp.31-39
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• 1990

Deck wetness phonomena has long been considered as one of the factors that degrade the performance of a ship in waves. In rough weather, the frequent shipping of water may give rise to the capsizing of the ship. Therefore an appropriate above water bow design is an improtant assert to a ship of which successful performance in rough weather is a prerequisite such as a warship. In this paper the experimental technique for estimation of deck wetness frequency is presented. The results of the model tests are compared with those of calculation using Ochi's formula. Finally the applicability of Ochi's formula is discussed.

• 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.

• Communications of Mathematical Education
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• v.25 no.2
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• pp.361-379
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• 2011

The purposes of this research are to develop Engineering Mathematics materials using the relations between Engineering Mathematics contents and not only pre-study contents but also major contents and to find the effect of the mathematics study which is applying them for students majoring in electronics. To accomplish the goals, I made list of Engineering Mathematics contents which is necessary to study electronics. Based on the list, I researched relations between Engineering Mathematics contents and not only pre-study contents but also major contents. After research, I selected some subjects which are related each other, developed study materials and examined responses to the materials. Then I analysed the effects on study attitude after used developed materials in my class. As a result, the major contents which was described in the introduction of the materials helped students to be motivated to study Engineering Mathematics and Pre-study contents described before Engineering Mathematics contents helped them to concentrate on studying Engineering Mathematics. Also it showed that developed study materials were effective in increasing self-confidence which is one attitude in the subcategories for Mathematics study.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.1
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• pp.51-55
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• 2009

Volar rotatory dislocation of the proximal interphalangeal joint(PIP) of the finger is rare. We report a female judo player who had volar rotatory dislocation of the PIP joint of the middle finger. She had dislocation of PIP joint total 4 times. At operation, the central tendon was identified as being distension, with the ulnar collateral ligament ruptured. The ruptured ulnar collateral ligament was interposed within the joint. The ruptured ulnar collateral ligament was repaired and extensor expansion was repaired. At last follow-up, she didn't have recurrent dislocation during judo. Accurate diagnosis, early intervention and progressive rehabilitation of this injury are very important as other dislocations.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.1
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• pp.34-42
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• 2017

In rough seas, green water shipped on board may impose quite large impact loads on the structures on deck and sometimes result in structure damages. One of the essential tasks of the naval fluid engineers is to provide the design impact loads which are needed for proper design of the structure strength against the green water impacts. Computation of the design impact load due to green water needs first a process to find the sea condition and the ship cruising condition which cause maximum green water impacts on structures as well as other succeeding processes to compute ship motion responses, green water flows and impact loads. Also, as a bold and practical process, it is needed that the irregular real seas are to be substituted by design regular waves which are equivalent in view points of green water impacts. In this paper, the whole processes to compute the design green water loads acting on bow structure are set up creatively. And the green water design impact loads acting on the box-type structure of a high-speed ship's bow are computed and discussed.

• Journal of Life Science
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• v.18 no.1
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• pp.30-37
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• 2008

The purpose of this study was to investigate the effect of Isotonic Training and Isotonic isometric complex Training to Knee joint Isokinetic muscle function in the high-school Taekwondo athlete. This subjects were randomly divided into two groups; a Isotonic Training group (n=7) Isotonic isometric complex Training group (n=7), Taekwondo athletes share each, 12 weeks between executes a motion. peak torque, H/Q ratio, bilateral muscular ratio muscular endurance of knee joint measured. For this study, two-way ANOVA with repeated measure were used. The result of this study presents between groups was not plain difference expressed. H/Q ratio, bilateral muscular ratio, muscular endurance was plain difference expressed after 12 weeks point of time (p>0.05) and peak torque was plain difference expressed (p<0.05). Conclusion each group did not appear all but one (peak torque), but point of view exercise was effect H/Q ratio, bilateral muscular ratio, muscular endurance, peak torque plain difference expressed.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.357-368
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• 2020

This study evaluated soccer-specific fitness early and late season to check the conditioning status of K3 league soccer players. Evaluation factors included body composition, agility, quickness, endurance and isokinetic limb muscle strength. As a result, the factors that showed improvement in the late season were skeletal muscle mass, agility and quickness, and body composition, endurance and isokinetic limb muscle strength were not different from each other. The factors that showed improvement in the second half of the season are thought to be due to the learning effect of repetitive training, competition participation during the season. Lastly, endurance and lower extremity strength did not show improvement in the second half of the season due to the fact that no specific training was performed during the season. Taken together, it is necessary to periodically check the fitness status of athletes to develop and apply a fitness training program suitable for competition, transition and preparation period.