• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.115-119
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• 2001

The simulation of motion responses of a dolphin-moored ocean structure in shallow water when it cllides with a ship, has been carried out. The equation of motion in the time domain according to Cummin's theory is employed, and solved by making use of the Newmark-${\beta}$ method. The added mass and damping coefficients involved in the equations are abtained from a three-dimensional panel method in the frequency domain. The impact forces due to ship collision are calculated using both the elastic and non-elastic modelings. The mooring forces for dolphin systems of ocean structure are regarded as linear spring forces.

• The Journal of Korea Robotics Society
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• v.9 no.4
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• pp.225-231
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• 2014

Fish generates thrust with a compliant fin which is known to increase the efficiency. In this paper, the performance of a robotic dolphin, the velocity and the stability, was improved using an optimal compliant caudal fin under certain oscillating frequency. Optimal compliance of the caudal fin exists that maximizes the thrust at a certain oscillating frequency. Four different compliant fins were used to find the optimal compliance of the caudal fin at a certain frequency using the half-pi phase delay condition. The swimming results show that the optimal compliant fin increases the velocity of the robotic fish. The compliance of the caudal fin was also shown to improve the stability of the robotic fish. A reactive motion at the head of the robotic dolphin causes fluctuation of the caudal fin. This phenomenon increases with the oscillating frequency. However, compliant fin reduced this fluctuation and increased the stability.

• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.9-18
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• 1998

An improved evaluation method of load-carrying capacity for the large-scaled offshore structures, which subjected to the axial force and bending moments simultaneously at the piles, was suggested with reliability analysis and advanced working stress method. Reliability analysis requires the fracture probability and safety factor(${beta}$) for each of forces and the load-carrying capacity due to combined action of axial force and bending moments from $P_n - {beta}$ Curve. The combined equation due to those forces, which suggested by the Korean Specification for the marine structure, was derived for the advanced working stress method and applied to evaluate the load-carrying capacity of jacket-type dolphin piers.

• Animal Systematics, Evolution and Diversity
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• v.29 no.2
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• pp.175-178
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• 2013

The Fraser's dolphin, Lagenodelphis hosei has a pantropical distribution. Only several stranding or catch data were available from Japan and Taiwan in the north-west Pacific region. An adult female L. hosei stranded in Jeju-do, Korea. The specimen was identified by external features and skull measurements. It showed the same external appearance ratio and range in the number of teeth with L. hosei former described. The cranial measurements also well corresponded to condylobasal length proportions given in the previous descriptions of the holotype. This is the first record of the species in Korean waters. We report the information on external and osteological characters of the specimen.

• Journal of Veterinary Clinics
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• v.27 no.4
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• pp.497-499
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• 2010

Cutaneous injuries stung by jellyfish are not uncommon in human exposed to marine environments. Most of the cases occur to scuba divers, fishermen, and travelers swimming at the beach. The symptoms vary from mild dermatosis to fatal systemic reaction. Some group of jellyfish like Atlantic Portuguese man-of-war (Physalia physalis) provokes acute severe skin injuries with systemic symptoms of nausea, bradycardia, and rarely anaphylaxis. But it is unusual case that allergic dermatitis caused by Scyphistoma which is polyp stage of jellyfish (Aurelia aurita) happened to zoo keepers working at indoor dolphin pool. This case report is about dermatosis with symptoms such as painful, irritant, itching, and erupted skin lesions on the neck and face of zoo keepers working at dolphinarium in Seoul zoo, Korea.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.103-107
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• 2001

When ship claps against the ocean structure sited at shallow water, the time simulation of motion responses of dolphin-moored ocean structure is presented. The equatien of motion based on Cummin's theory of impulse responses are employed, and solved in time domain by using the Newmark $\beta$ method. The added mass and damping coefficients involved in the equations are obtained from a three-dimensional panel method in the frequency domain. The impact forces due to ship collision are modeled as two method, and those are elastic and non-elastic collisions. The mooring forces for dolphin systems of scean structure are considered as linear spring system.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.11-21
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• 2007

The study was undertaken to present the quantitative materials available in underwater industries, underwater rehabilitation & physical training through comparison & analysis of effects contributing to propulsion of COG by types of fin-kick in underwater activities. For this 3D cinematography was performed for the skilled subjective and conclusions obtained on the basis of analysis of kinematic variables were as follows. In temporal variable the delay in the order of flutter>side>dolphin kick in elapsed time by total & phase resulted in longer sliding phase by larger fin kick of extension & flexion of both leg and thus more contributed in propulsion of COG. than those of the otherwise. In linear variable the contribution ratio to the result of propulsion of COG in both propulsive(mean $35.39{\pm}7.93cm$ in Y axis) and sliding phases(mean $66.36{\pm}11.01cm$ in Y axis)was shown to be order of flutter>dolphin>side fin kick. the maximum velocity of COG in Y direction was showed in both propulsive and sliding phases, and the contribution ratio to the propulsion of COG was in the order of flutter$\geq$dolphin>side fin kick. In angular variable the Significant difference in angle of leg joint by types of fin kick in both leg was showed but no routine order. The Significant difference in angular velocity of leg joint by types of fin kick in both leg was showed in the order of flutter>dolphin$\geq$side fin kick in propulsive but no in sliding phase. The Fluid resistance by tilting angle of trunk in both propulsive and sliding phase was decreased in the order of flutter>dolphin$\geq$side fin kick and tilting angle of trunk of the skilled was smaller than that of the unskilled in difference of maximum mean 7.97degree and minium mean 2.06degree. In summary of the above, It will desirable fin kick type because of more contribution to COG propulsion by the velocity & displacement in Y-axis and less fluid resistance by tilting angle of trunk and larger angular velocity in the case of more delayed in elapsed time of propulsive phase than that of the otherwise.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.3-16
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• 1999

The objective of BMP( Barge Mounted Plant) project is to construct plants on mooring floating structures at sea. To analyze the pile behavior under mooring dolphins, generally, axial or lateral behavior of soil-pile system is evaluated by using a nonlinear subgrade reaction method which models the pile as a structural element and the soil as series of nonlinear springs along the depth. As a result, load-displacement curves at pile head can be solved by finite difference method and the equivalent stiffness of bottom boundaries of dolphin structure is evaluated. In this study off-shore site investigation was performed on the marine area of Koje Island and axial and lateral load transfer curves of the ground were modeled with depth. The subgrade reaction analysis was performed for piles under axial or lateral loadings, and the required penetration depth and section of the pile were determined. Subsequently, the spring boundaries under the dolphin structure could be modeled from the calculated load-displacement curve and then the dynamic response of the dolphin structure was analyzed reasonably by considering ground conditions. The analysis considering the stiffness of the soil-pile system has resulted in larger displacement amplitudes than those for rigid foundations. Furthermore, moment distributions of the casing were dependent on the soil-pile system so that deformable foundation induces the larger moment of top section of casing and the smaller moment of pile head.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.3
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• pp.285-294
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• 2000

In this paper, a practical procedure for the design optimization of tubular-steel-pile-type substructure in a mooring dolphin is investigated and numerically evaluated. In the finite-dimensional optimum design formulation, geometry and cross-sectional shapes of classified group of piles are identified as design variables. The design objective is the total weight of piles, and the design constraints on stresses, penetration depth, and size limits are imposed. Several classes of practical design alternatives are sought through the linking and fixing of design variables. Among the available numerical optimization codes, both PLBA program and DNCONF subroutine in IMSL library are used. They are based on SQP algorithm and relatively easy to get. A dolphin of numerical example has 20 tubular steel piles, 4 vertical and 16 inclined. Optimum designs for different cases are successfully obtained for the practical purpose.

• Ocean and Polar Research
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• v.33 no.1
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• pp.35-43
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• 2011

Blubber plays different biological roles in cetaceans, including structural support, physiological demands (thermoregulation, streamlining, buoyancy, etc.), and energy storage. As such, biochemical composition, especially lipid, in the blubber may be vertically stratified in order to effectively assist with these functions. We analysed lipid content, class and fatty acid composition in the blubber of by-catch minke whale (Balaenoptera acutorostrata; n = 11), long-beaked common dolphin (Delphinus capensis; n = 3) and Pacific white-sided dolphin (Lagenorhynchus obiquidens; n = 2) from Korean waters. Lipid content for all three species ranged from 55 to 96% of wet weight, with a dominance of triacylglycerols. Vertical stratification of blubber lipid content was different between species. For minke whale and longbeaked common dolphin, it increased from inner (near the muscle) to outer (near the skin) layer, whereas it decreased for Pacific white-sided dolphin. Thirty-one fatty acids were found in all blubber samples and vertical stratification of fatty acid composition was similar among all three species. Among grouped fatty acids, monounsaturates were the most abundant, gradually increasing from inner to outer blubber layer, whereas polyunsaturates and saturates decreased. Such vertical stratification of lipid content and composition suggests that the modification and accumulation of lipid occur in the blubber itself in order to help cetaceans with their specific physiological needs.