• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.2
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• pp.311-318
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• 2015

Red tide occurs every year in the coastal seas of the South Korea, This phenomena has become a national issue of environmental and economic damage. In this study, we analyzed a suitable conditions to occur the red tide by using oceanic and atmospheric data during 10 years, These factors were applied to predict the red tide occurrence from 2012 to 2014. As a result, in 2012 and 2013, it is able to alarm the red tide occurrence before 6~11 days. However, in compared to the normal year and 2014, the prediction of red tide occurrence were less accurate because of more precipitation, short sunshine duration, low temperature waters. Therefore, it is necessary to further investigate the impact of sunshine duration(Solar radiation) on red tide occurrence, it is more necessary to consider the comprehensive analysis using additional oceanic and atmospheric factors.

• Korean Journal of Remote Sensing
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• v.24 no.4
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• pp.325-331
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• 2008

We propose an algorithm to detect large Cochlodinium polykrikoides red tide event that was appeared in Korean coastal waters. This algorithm is based on two-stage filtering using MODIS chlorophyll information. Most of the red tide detection studies generally use assumption that sea water having high chlorophyll concentration is red tide events because of high correlation and red tide. However, these methods generate many commission errors such as turbid water by detecting inactive sea water of red tide. Therefore, we eliminated commission errors by applying two stage filtering and verified the algorithm's effectiveness by detecting large Cochlodinium polykrikoides red tide event that was appeared in Korean coastal waters.

• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.542-550
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• 2011

Changes of suspended sediment concentration in the Seomjin river estuary located in south sea of the Korea peninsula were investigated during the spring tide in autumn (i.e. 25 hours in October) 2000 and winter (i.e. 25 hours in February) 2001. The changes of temperature and salinity during the spring tide in October 2000 showed larger variations than the those in February 2001. During the spring tide in October 2000, currents at bottom layer were observed to be stronger than during the spring tide in February 2001, showing that both of the two periods had ebb currents-predominant tide asymmetries. The suspended sediment concentrations in October 2000 were larger than the those in February 2001. At the time of the maximum of tide currents or after about one hour of the maximum during the autumn months, the suspended sediment turbidity was observed to be maximum. Another observation station at Hadong upstream from the Seomjin river estuary showed about one hour delay in tide phase, Thereby, the suspended sediment concentration showed high turbidity after two hours at bottom and three hours at surface layer, in particular, in October 2000. This results can be explained by the facts that river discharge increased significantly after the summer rainy season, causing also increase of erosion processes by strong current velocity at bottom layer.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.2
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• pp.101-105
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• 2008

We applied web-standard technologies like XHTML CSS etc. to Mobile Tide Forecasting System. Through mobile hot key(659+hot key), users can connect the system and get conveniently the tide forecasting information in mobile communication environment.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1048-1049
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• 2015

The sihwa tidal power plant is the first tidal power plant in korea and the biggest of the world. The tidal power turbine is operated by tidal energy. The tidal energy is generated by the relative motion of the earth and celestial masses specially the sun and the moon, which interact via gravitational forces. The tidal power is estimated by the predicted the tidal amplitude and phase. This paper gives a process of estimate of tidal power using Matlab T-tide based on tide prediction. The proposed method is tested using actual recorded data comparing to predicted date.

• Journal of Environmental Science International
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• v.6 no.3
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• pp.231-238
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• 1997

The community of phyloplankton and water quality were Investigated 5 times from October, 1994 to October, 1995 In the east area of Chinhae Bay. Seasonal changes of enoronmental parameters were shown general pattern and related to the red tide mechanism of phytoplankton community. Seasonal variations of dissolved oxygen concentrations were affected by the photosynthetic activity of phytoplankton community and the Increase of COD at the bottom water was occurred after the red tide. The standing stocks of phytoplankton In this study area ranged 202 - 1616 Cells . ml-1 and the bloom(red tide) was formed from April to July. The diatom species, Skeletonema costahm was a dominant species all the year round and the dinoflagellate species, Alexandrium tmuense and prorocentrum triestinum were red tide species Increased standing stocks in phytoplankton bloom.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.573-580
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• 2019

A submerged breakwater is a coastal structure built under water with excellent landscape. The depth of the crest of the breakwater should be maintained at more than a certain level in order for the submerged breakwater to control waves properly. This means that the effect of blocking waves deceases sharply at high tide in coastal areas with large tidal differences. In this study, we proposed a Tide-Adapting Submerged Breakwater (TA-SB) to overcome this problem, and then we conducted hydraulic model experiments to evaluate the performance of the TA-SB for controlling waves. The experimental results showed that the tapered wings attached to the crest of the TA-SB helped induce forced breaking waves. In particular, they were very effective in blocking waves and attenuating wave energy at high tide. In addition, the wave control performance of the proposed TA-SB was far superior to the Tide-Adapting Low-Crested Structure (TA-LCS) of the previous study.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.1-8
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• 2013

This study was performed for the purpose of analyzing the effect of tide on the stress-strain behavior in the boundary surface of sea dike embankment. Tide is a dynamic condition, but there are not suitable numerical models to solve the dynamic embankment condition caused by tide. So the analysis was simplified to quasi dynamic as follow. First, seepage by tide was analyzed according to elapsed time, and the results of the analysis at every hour during one periodic cycle time of 12 hours were applied to the pore water pressure conditions of stress-strain analysis with hyperbolic model by Duncan and Chang. The place at which maximum shear strain took place in the analysis result moved up and down repeatedly along the boundary of the dredged sand fill section and the crashed stone filter section. The value of maximum shear strain was large at high water level of tide. This result means that contraction and relaxation occur in turn repeatedly at every specific position along the boundary, and the repeated action compact loose position with sand moved down from the upper position by gravity. The experiment with the small sea dike model showed the result consistent with the numerical analysis. The surface of sea side on the dike collapsed at high water level after a couple of repetition of the rising and falling of water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.359-370
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• 1992

To investigate the flow pattern and mixing process in Suyoung Bay, field observations and data analyses of tidal current, salinity and suspended sediment (SS) were carried out. Ebb flow is stronger than flood flow, and duration of ebb tide is longer than that of flood tide. Semi-diurnal component of tidal current is predominant, and current rotating clockwise occurs in the central part of the bay. The direction of the residual currents in the central part of the bay and offshore is almost N to WNW, and the speed is 4-14cm/s. Eulerian diffusion coefficients estimated from the current data have the range of $6.2\times10^4-4.2\times10^6\;cm^2/s,$ Salinity structure in Suyoung River estuary during flood tide is of partially mixed type, but is of stratified type during ebb tide. Salinity fluctuation is large at the surface, and the fluctuation decreases with depth. SS concentration in Suyoung River estuary has a higher value during ebb tide than that during flood tide. Salinity and 55 concentrations in the estuary appeared to be very sensitive to the change of river flow.

• Geophysics and Geophysical Exploration
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• v.14 no.2
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• pp.133-139
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• 2011

The largest terms in the solid Earth body tide calculation are second degree spherical harmonic components due to the moon or the sun, and they compose about 98 percent of total contribution. Each degree harmonics of the tidal perturbation should be evaluated through multiplication with distinct Love numbers or their combinations. Correct evaluation of these terms in gravity tide is considered with re-calculated Love numbers. Frequency dependence of Love numbers for spherical harmonic tide upon the order number is discussed. Tidal displacement and tidally induced deviation of the vertical are also evaluated. Essential concepts underlying the body tide calculation are briefly summarized.