• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.7
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• pp.551-560
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• 2004

A method how to determine the shock response spectrum from the FRF of the statistical energy analysis( SEA ) is presented here. The system of 3 different Plates connected by bolt joints is selected simulating missile structural sections Joined together. First, the SEA model was rendered by SEA parameters which were determined from experimental SEA method. Then, the mobility power was input to the SEA model and we can verify the validity of the model in the medium to high frequency range checking the reproduction of output average velocity. And, the shock induced shock response spectrum(SRS) was obtained using SEA FRF and arbitrarily chosen experimental FRF. We have compared the thus obtained SRS with actually measured SRS and they were relatively in good agreement. In this paper, we used the measured SEA FRF and therefore we have got the SRS well agreed with actually measured SHS even in the low frequency range. If the SEA FRF of well verified SEA model is used, the good result will come out in SEA effective frequency range which is more important at SRS.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.546-551
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• 2013

This study examined the effects of the dietary inclusion of Porphyra and sea tangle Laminaria japonica on the growth, feed utilization, body composition, and plasma chemistry of juvenile Korean rockfish Sebastes schlegeli. Eight hundred and forty juvenile fish averaging 5.0 g were allocated 40 fish per tank to 21 180-L flow-through tanks. Seven experimental diets were prepared: control (Con) without additive, 0.5 and 1% Porphyra extract (PE), 3% Porphyra powder (PP), 0.5 and 1% sea tangle extract (STE) and 3% sea tangle powder (STP), referred to as PE-0.5, PE-1, PP-3, STE-0.5, STE-1, and STP-3, respectively. Each additive was included in the experimental diet at the expense of the same amount of wheat flour. Each experimental diet was fed to triplicate groups of fish. The experimental diets had no effect on the survival, weight gain or specific growth rate of the fish, feed consumption, feed efficiency ratio, protein efficiency ratio, protein retention, hepatosomatic index, condition factor, moisture or crude protein content of the entire body excluding the liver or moisture, crude protein or crude lipid content of the liver. None of the plasma parameters were affected by the experimental diets. Based on these results, the dietary inclusion of Porphyra and sea tangle did not affect the growth, feed utilization, body composition or plasma chemistry of juvenile Korean rockfish.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.359-364
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• 2002

Statistical energy method is widely used for the prediction of vibrational and acoustical behavior of complex structures, such as ship building and automobile in mid-, high frequency ranges. However. in order to convince this SEA result, it is important to verify estimated SEA parameters, e. g. modal density, energy in each subsystem, damping loss factor, coupling loss factor. with possible other method. For modal density parameter, the experimental estimations via Experimental Modal Analysis are checked with those from finite element method for both beam- plate and plate-plate cans. Loss factors are calculated by Lyon's simple method for the two subsystem. finally. modal experiments are carried out by varying the mass added on the junction of two subsystem for the purpose of investigating the influence on the coupling loss factor's behavior.

• Journal of Gifted/Talented Education
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• v.18 no.1
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• pp.139-165
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• 2008

This paper is focused on the development of sea wave experimental module for the science gifted students and the potential of its application in high school earth science. Sea wave experimental module for the gifted was characteristics by five phases: Engagement, Exploration, Explanation, Elaboration, and Expansion. Subjects were 16 gifted students, who were 10th graders and have been taught in the adjacent Education Institute for the gifted of Education Districts, Daejeon Metropolitan Office of Education The changes of inquiry ability and knowledge achievement were analyzed according to analysis of experimental report and pre-test and post-test. Experimental module for the gifted was very effective on inquiry skills as follows: control of variables, experimental designing, and selecting tools of experimental process. And also it was positively effective on achievement. The result of this study suggested that experimental module for the science gifted should be very meaningfully to improve scientific ability of them, and the development and application of experimental module for the science gifted be needed for them.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.342-349
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• 1998

The objective of this study is to investigate the characteristic change of antiwashout underwater concrete with variation of blend ratio of sea sand and fine aggregate percentage through experimental researches. According to the experiments results, when sea sand are mixed in antiwashout underwater concrete mixture by about 40% per total fine aggregate, in fine aggregate percentage of 40%, it is found that the flowability fit and the compressive strength is higher others.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.4 no.1
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• pp.10-21
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• 2001

A new method of laser remote sensing is proposed, based on sensing the sea surface by a narrow laser beam (2-3cm) and analyzing statistically specular reflections. Construction of the angular dependency of the average density of specks versus the aircraft flight horizontal azimuth allows calculation of both intensity and azimuthal properties of the sea surface spectrum. The paper contains the experimental setup and technique, the field measurement data taken onboard an aircraft and the examples of calculated main statistical parameters of sea waves. Their energy-carrying component velocity is found by the mean velocity of an ensemble of specular points at the random sea surface. The surface wave nonlinearity is shown to affect substantially the statistical characteristics measured: mean numbers of specular areas with th given elevation and given slope, arranged along the line of crossing the sea surface by the scanning laser beam. Experimental measurement of a variance in the number of these areas yields a principal possibility to calculate the correlation function of the sea surface without its preliminary modeling.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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• pp.529-537
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• 1998

Currently as due to the rapid development of industry and increase in population we meet serious problems concerning the shortage and pollution of water. In the country many experts predict a shortage of water approaching 450 million tons by the year 2006. To cope with this serious problem it is necessary to construct desalination plants. In the adoption of a desalination system the most important factor is the cost of fresh water production,. In general LNG is stored in a tank as a liquid state below $-162^{\circ}C$. When it is serviced, however the LNG absorbs energy from a heat source and transforms to a high pressure gaseous state. During this process a huge amount of cold energy accumulated in cooling LNG is wasted. This wasted cold energy can be utilized to produce fresh water by using a sea water freezing desalination system. In order to develop a sea water freezing desalination system and to establish its design technique qualitative and quantitative data regarding the freezing behavior of sea water is required in advance, The goals of this study are to reveal the freezing behavior of sea water is required in advance. The goals of this study are to reveal the freezing mechanisms of sea water to measure the freezing rate and to investigate the freezing heat-transfer characteristics,. The experimental results will provide a general understanding of sea water freezing behavior in a rectangular vessel cooled from above.

• Journal of Fisheries and Marine Sciences Education
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• v.12 no.2
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• pp.199-212
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• 2000

It is very important to investigate the hull response of a fishing vessel in the sea to ensure the safe navigation and fishing operation in rough sea by preserving excellent sea keeping qualities. For this purpose, the author measured various responses of three stem trawlers in waves using real sea experimental measuring system. The author analyzed the experimental data using the statistical and spectral analyzing method to get the characteristics of the motion responses of the vessels according to the wave height and the ship's speed. The results obtained can be summarized as follows ; (1) Rather higher response of the pitch motion due to the wave height appeared in the head sea and the bow sea than any other wave direction without relevance to ship's size. In case of the roll motion, the beam sea and the quartering sea have a high response value. The period of peak of the pitch motion and the roll motion according to the wave height in each vessel has almost same value respectively. (2) The change of response of the pitch motions deeply depend on the ship's speed in the head sea and the bow sea, but not in the other wave direction. (3) The change of response of the roll motions in the beam sea, the quartering sea and the following sea are affected by the influence of the ship's speed in 5k't to 8k't, but not related to the ship's speed in out of that range.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.6
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• pp.1250-1259
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• 2001

This study was experimentally performed to investigate sea water freezing behavior along parallel cooled plate with bubbly flow The experiments were carried out for a variety of parameter, such as sea water velocity, air-bubble flow rate, and cooled-plate temperature. The shape of freezing layer, freezing rate and salinity of frozen layer were observed and measured. It was found that the experimental parameters gave a great influence on the freezing rate and the salinity of the frozen layer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.142-147
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• 2018

This study was conducted to investigate the effects of practical diets containing different seaweed powders on the growth and body composition of juvenile sea cucumber Apostichopus japonicus. Six experimental diets were formulated to contain 40% of the following seaweed powders: Sargassum thunbergii (ST), Undaria pinnatifida (UP), Ascophyllum nodosum (AN), Hizikia fusiformis (HF), fermented Laminaria japonica (FLJ), and fermented Hizikia fusiformis (FHF). Sea cucumbers (30 per tank; initial mean weight $0.4{\pm}0.01g$) in three replicates of six groups were fed one of the six experimental diets for 15 weeks. Survival in all groups was 83-93%, with no significant differences among the experimental groups. The specific growth rates of the sea cucumbers fed the ST and UP diets were significantly higher than those of sea cucumbers fed the HF, FLJ, and FHF diets, but did not significantly differ from those of sea cucumbers fed the AN diet. The results of this study suggest that S. thunbergii, U. pinnatifida, and A. nodosum could be useful sources of seaweed powder for practical diets of juvenile sea cucumber.