• 한국초등과학교육학회지:초등과학교육
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• 제36권1호
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• pp.1-15
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• 2017

The purpose of this study is to analyze the problems of land and sea breeze model experiment that has presented in $5^{th}$ grade curriculum in chapter "Weather and our lives" and makes better model simulation so that learners can have better and more effective way to study it. To survey the opinions from dedicated teachers about land and sea breeze model experiment, we produced the survey through interview with science exclusive teacher from M elementary school. An elementary science education expert, 3 men of science EdD modified and complemented survey and started Delphi survey to 12 science teachers who have career teaching more than 3 years. The problems found in this survey were 'one heat bulb, short heating time, small temperature difference of water and sand, lack of class time, empty space between sand and water, back of transparent boxes, little amount of scent and the location of the it' etc. But the most of all, it is hard to see the successful result of the experiment. Based on these kinds of investigations, and lots of trial and error, redesigned the new model experiment that has the most similarity to the real one and high probability of success. According to this, it was able to see the smoke forms horizontal movement along the sand and the smoke goes in one circulation cycle. through this experiment, we made a conclusion that although those scientific experiments in textbook were developed through lots of considerations of expert, to consider the aspect of consumer, it needs to reach the educational agreement about simulation experiment so that It can lead to successful experiment and high quality education.

• 한국수산과학회지
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• 제52권5호
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• pp.524-533
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• 2019

Sea urchins are hugely destructive of marine forest ecosystems. This study aimed to determine the behavioral response of purple sea Urchins Heliocodaris crassispina to food and an electrical stimulus and to investigate the attraction radius of these stimuli, with an eye to the development of technology for controlling sea urchin numbers. Ten purple sea urchins, housed in circular acrylic tank, were tested against various attractant stimuli. In addition, an experiment was conducted with 200 purple sea urchins in a large water tank to observe movement patterns and the attractiveness of various stimuli. In the smaller experiment, eight out of 10 sea urchins were attracted to food, and these attractive effects were maintained in all except one of the affected urchins. However, the attractant effects of the electrical stimulus were maintained in only three sea urchins. The results of the larger experiment indicated that differences in the attractant power of food and an electrical stimulus were 54%-78%, and approximately 5-15% of sea urchins were attracted by the electrical stimulus.

• 대기
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• 제17권3호
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• pp.241-253
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• 2007

This paper investigates summer precipitation change in East Asia according to switching surface boundary condition over South Korea and Shantung. Simulations are carried out by ECHO-G/S for 20 years (1980-1999). Surface condition over both areas in ECHO-G/S is represented by ocean (OCN experiment). In OCN experiment, the summer precipitation is considerably underestimated around the Korean peninsula (the dry region) and overestimated over the eastern Tibetan Plateau (the wet region). It may be related that the lack of the heat sources from the unrealistically prescribed land-sea mask weakens northward expansion of rainband and the development of convective precipitation. Moreover the simulated rainband retreats before June in connection with the early genesis of summer monsoon circulation. The systematic bias of the summer precipitation over the dry and wet regions are reduced comparing with the OCN experiment when the land-sea masks over South Korea and Shantung are realistically considered as land (LND experiment). These improvements can be explained by the thermodynamical dissimilarity between land and ocean. Enhanced warming by switching the areas from sea to land has led to develop the thermal low over Yellow Sea with the cyclonic circulation. Thus, this cyclonic circulation supports moistures from the south to the dry region and blocks to the wet region. The heat transport from the land surface to atmosphere plays a key role in the developing convective precipitation in local scale and maintaining the precipitation and the rainband. Therefore, this results indicate that the design of the realistic land-sea distribution is required for the accurate simulation of the regional precipitation.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1062-1067
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• 2015

Floating architecture is a type of building that is geographically located on a sea or a river. It floats under the influence of buoyancy, and does not have an engine for moving it. Korea is a peninsula surrounded by sea except on the north side, so floating architectures have been mainly focused on two points: solving the issue of small territory and providing various leisure & cultural spaces. Floating architectures are expected to save energy effectively, if they use sea water heat, which is known to be clean energy with infinite reserves. To use sea water heat as the heat source and/or heat sink, this study proposes a model in which a sea water heat exchanger is embedded in the concrete structure in the lower part of the floating architecture that is submerged under the sea. Based on the results of performance evaluations of the sea water heat exchanger using CFD (computational fluid dynamics) analysis and mock-up experiments under various conditions, it is found out that the temperature difference between the inlet and outlet of the heat exchanger is in the range of $3.06{\sim}9.57^{\circ}C$, and that the quantity of heat transfer measured is in the range of 3,812~7,180 W. The CFD evaluation results shows a difference of 5% with respect to the results of mock-up experiment.

• 대기
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• 제31권3호
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• pp.283-294
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• 2021

An Observing System Experiment (OSE) using Global Ocean Data Assimilation and Prediction System (GODAPS) was conducted to evaluate the assimilation impact of Argo floats, deployed by National Institute of Meteorological Sciences/Korea Meteorological Administration (NIMS/KMA), in marginal seas around Korean peninsula. A data denial experiment was run by removing Argo floats in the Yellow Sea and the East Sea from an operational run. The assimilation results show that Argo floats bring the positive impact on the analysis of ocean internal structure in both Yellow Sea and East Sea. In the East Sea, overall positive impact in the water temperature and salinity context is found, especially outstanding improvement from 300 to 500 m depth. In the Yellow sea, the assimilation impact on water temperature and salinity is also large within 50 m depth, especially greater impact than the East Sea in salinity. However, in the Yellow Sea, the influence of Argo floats tends to be restricted to the vicinity of Argo floats, because there was only one Argo float in the middle of the Yellow Sea during the experiment period. Given that the only limited number of Argo floats generally contribute in a positive way to the improvement of the GODAPS, further progress could be expected with adding more observations from Argo floats to current observing systems.

• 한국수산과학회지
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• 제49권1호
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• pp.26-29
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• 2016

This study investigated the effects of dietary inclusion of sea mud on growth and body composition of juvenile sea cucumber Apostichopus japonicus. In experiment 1, three experimental diets containing sea mud at the level of 0, 30 and 60% were prepared. After feeding trial for 7 weeks, survival was not significantly different among groups. Final mean weight of sea cucumber fed the experimental diet without sea mud supplementation was significantly higher than that of sea cucumber fed the diet containing 30 and 60% sea mud. In experiment 2, three experimental diets containing sea mud at the levels of 0, 15 and 30% were prepared. After feeding trial for 19 weeks, survival was not significantly different among groups. Final mean weight of sea cucumber fed the diet without sea mud supplementation was not significantly different from that of 15%, but was significantly higher than that of sea cucumber fed the diet containing 30% sea mud. It was concluded that dietary inclusion of sea mud may inhibit growth of sea cucumber.

• Ocean and Polar Research
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• 제34권3호
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• pp.337-348
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• 2012

This study investigates the effects of tide, wind and oceanic currents on oil spill dispersions through a series of numerical floats tracking experiments on the Sea Prince oil spill incident occurred in 1995 using a 3-dimensional high resolution ocean circulation model. For that, a total of four experimental cases (experiment with tide, wind and oceanic currents, experiment with tide and oceanic currents, experiment with wind and oceanic currents, and experiment with tide and wind) were compared. It could be seen that results from experiment involving all external forces showed better agreement with the observed pattern of oil slick movement than other cases. The oceanic currents acted to drive floats to move to the western channel of the Korea straits and wind accelerated the eastward movement of floats in the early stage of the incident. Tidal currents played significant role in the horizontal dispersion of floats.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1343-1345
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• 2003

An internal wave observation experiment by SAR in South China Sea is described. Two scenes of Radarsat ScanSAR images were acquired. Internal solitary waves are found in all the two images. It is concluded that these internal waves are generated in Bashi channel. Relationship between internal wave generation and tide is studied based on analyzing of tidal data of Legaspi in Philippine. Using ocean environmental data of this sea area internal waves’ amplitude and wave speed are detected by SAR images.

• 환경영향평가
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• 제11권2호
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• pp.79-91
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• 2002

Four dimensional data assimilation (FDDA) technique was considered for 3 dimensional wind field in coastal area and a set of 3 numerical experiments including control experiments has been tested for the case of the synoptic weather pattern of the weak northerly geostrophic wind with the cloud amount of less than 5/10 in autumn. A three dimensional land and sea breeze model with the sea surface temperature (SST) of 290K was performed without nudging the observed wind field and surface temperature of AWS (Automatic Weather System) for the control experiment. The results of the control experiment showed that the horizontal temperature gradient across the coastline was weakly simulated so that the strength of the sea breeze in the model was much weaker than that of observed one. The experiment with only observed horizontal wind field showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated. However, the horizontal wind speed and vertical motion in the convergence zone were weakly simulated. The experiment with nudgings of both the surface temperature and wind speed showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated even though the ending time of the sea breeze was delayed due to oversimulated temperature gradient along the shoreline.

• 수산해양기술연구
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• 제42권3호
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• pp.148-157
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• 2006

A model experiment, simulation test using personal computer and real sea trial fishing were carried out to investigate the basic efficiency of bottom trawl net which can be used in the sea mount of North West Pacific, and experimental values were analyzed as the values of full-scale bottom trawl net. Hydrodynamic resistance for the full-scale trawl net according to the Koyama equation was 2.1 times higher than that of simulation and 2.4 times higher than that of model experiment at the average towing velocity. At the 3.5kt's of towing speed, net width of the full-scale trawl net was 2.5% smaller than that of simulation and 8.2% larger than that of model experiment. On the fishing experiment of the full-scale trawl net for the 3.5kt's of average towing speed, average net height of A group(same direction with external force) was 423.5% higher than that of model experiment and 457.1% higher than that of simulation and that of B group(opposite direction with external force) were 283.8% and 306.3% higher than in case of model experiment and Simulation respectively. Net mouth of the full-scale trawl net was 338.1-504.6% higher than those of model experiment and simulation in A group, and 525.2-745.3% higher in B group.