• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.3
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• pp.290-297
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• 1994

As satellite altimetry is being progressed to apply with higher precision to marginal seas, it is necessary to improve correction procedures fer tidal signals in altimetry with more accurate tidal model than the well-known model of Schwiderski. The Bay of Bengal renders many conspicuous coastal oceanographic issues including tide and storm surge interactions along the upper Bangladesh coast. As a first step. tidal regime of semidiurmal tides (M$_2$, S$_2$, $N_2$, $K_2$) and diurnal tides (K$_1$, $O_1$, P$_1$) are computed with a model having a mesh resolution of 1/4 degree over the whole Bay of Bengal. Computed results are discussed with observation and previous Schwideski's tidal map of the region.

• ALGAE
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• v.32 no.1
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• pp.41-46
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• 2017

In rocky intertidal habitats, abiotic stress due to desiccation and thermal extremes increases with elevation because of tides. A study in Atlantic Canada showed that, at low elevations where conditions are benign due to the brief low tides, fucoid algal canopies (Ascophyllum nodosum and Fucus spp.) do not affect the structure of benthic communities. However, at middle and high elevations, where low tides last longer, fucoid canopies limit abiotic extremes and increase the richness (number of invertebrate and algal species, except fucoids) of benthic communities. Using the data from that study, this paper compares the intensity of facilitation and its importance (relative to all other sources of variation in richness) between middle and high elevations, which represent intermediate and high stress, respectively. Facilitation intensity was calculated as the percent increase in benthic richness between quadrats with low and high canopy cover, while the importance of facilitation was calculated as the percentage of variation in richness explained by canopy cover. Data for 689 quadrats spanning 350 km of coastline were used. Both the intensity and importance of facilitation were greater at middle elevations than at high elevations. As canopies do not affect benthic communities at low elevations, this study suggests that the facilitation-stress relationship at the community level is unimodal for this marine system. Such a pattern was found for some terrestrial systems dominated by canopy-forming plants. Thus, it might be ubiquitous in nature and, as further studies refine it, it might help to predict community-level facilitation depending on environmental stress.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.271-278
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• 1999

In order to clarify water quality, dynamics and structure of phytoplankton communities, and red tides, the present study was carried out monthly from July to September 1998 at 19 stations in Deukryang Bay. Water temperature varied from 24.$0^{\circ}C$ to 28.6$^{\circ}C$, and salinities ranged from 25.0$\textperthousand$ to 28.6$\textperthousand$. During red tides in July, chlorophyll-$\alpha$ contents were rather high in August, it showed that phytoplankton controlled primary production in this bay. Phytoplankton was composed of 89 diatoms, 19 dinoflagellates, and 3 silicoflagellates. Phytoplankton standing crops varied from a minimum of 1.3$\times$10$^4$cells/ι(Sept., St. 17) to a maximum of 3.8$\times$10$^{6}$ cells/ι (July, St. 10). Red tides occurred in July when the standing crops averaged 1.8$\times$10$^{6}$ cells/ι. Leading the causative organisms of red tide were Prorocentrun minimum in the upper bay, Chaetoceros curvisetus in the mouth and middle part of the bay, Ceratium furca and Thazassio- sira sp. around Nokdong Harbour. Concentration of nutrients such as nitrogen was high in the upper bay, during red tides, water temperatures varied from 23.8$^{\circ}C$ to 29.7$^{\circ}C$ and salinity were 23.l$\textperthousand$ to 27.0$\textperthousand$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.624-634
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• 1995

Tides at both of northern and southern entrances of Kamag Bay were compared by deploying tide gauges for 18 days during July-August 1994. To examine the response of the inner bay to the tidal waves through both entrances, a current meter was moored at the eastern pan of the inner bay. Current meter mooring failed at the northern entrance (Yosu) while the current data was collected for only 5 days at the southern site (Songdo). Maximum range was 357 and 352 cm at Yosu and Songdo, respectively. Respective amplitudes for M2, S2 Kl O1 tides of 95.5, 48.8, 20.5, 14.0cm at Yosu and 93.6, 47.2, 21.3, 13.1cm at Songdo yielded the form numbers of 0.23 and 0.24, respectively, both of which belong to the predominantly semidiurnal tide, Contributions from the overtides and compound tides were less than $4\%^ at both sites. Differences in Greenwich phase of major partial tides between two sites were negligible. Maximum speed of tidal current was about 100cm/sec at the southern entrance and about 40cm/sec at the inner bay. Residual current speed was 17cm/sec southwestward at the southern entrance and 0.9cm/sec southeastward at the inner bay. Temporal change in current at the inner bay showed that the wind had a significant influence upon the circulation in Kamag Bay.

• Journal of National Security and Military Science
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• s.7
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• pp.155-231
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• 2009

Xu-Jing(徐競) an official of the Song(宋), a medieval Kingdom of China, wrote a book titled $\ll$Koryo Tu Jing(高麗圖經)$\gg$ which explains his travel to the Koryo as a member of diplomatic mission in 1123. $\ll$Koryo Tu Jing$\gg$ is the record of his personal experience in Koryo with many explanatory illustrations and especially contains 5 months' voyage record of his diplomatic fleet. His fleet set sail at a port located in the Ding Hai Xian(定海縣), Ming Zhou(明州) via a few islands of Koryo [Hyup Kye San(俠界山) , the Kun San Do(群山島) , the Ja Yon Do(紫燕島) , the Keup Su Mun(急水門) in Kang Hwa Gun(江華郡) and the Hap Gul(蛤窟) ] and finally arrived the Port Ye Song Hang(禮成港) . According to the Xu-Jing's record his fleet sailed the sea with the help of the favorable seaward winds and tides as the usual way of ancient sailing. The Xu- Jing's Fleet sailed the sea between the Mei Cen(梅岑), Ming Zhou(明州) of China and the Hyup Kye San(俠界山) of Koryo from about 5:00 a.m., May 24th(of the lunar calendar) to about 5:00 p.m., June 2nd. At this section, the average speed of the seaward winds was 19.45km/h and the average speed of the fleet which sailed only by the power of the winds was 6.29km/h. This means that 32.3% of the favorable seaward winds' speed was equal to the speed of the ancient fleet which sailed only by the power of the favorable seaward winds. The fleet sailed the sea between the Ja Yon Do(紫燕島) and the Keup Su Mun(急水門) from about 9:00 a.m., June 10th to about 1:00 p.m., the same day. At this section the fleet sailed by the power of tides in addition to the favorable seaward winds without oaring. The average speed of the winds was not different from that of former section and the average speed of the tides was 1.937km/h. And at this section the average speed of the fleet increased by 0.41km/h than that of the former section. This means that 21.1% of the speed of the tides was equal to the increased speed of the ancient fleet by virtue of the tides. The fleet sailed the sea between Keup Su Mun(急水門) and the Hap Gul(蛤窟) from about 1:00 p.m., June 10th to about 3:00 p.m., the same day. At this section, there were no seaward winds and the fleet sailed only by the powers of tides and oaring. And at this section, the tide increased the average speed of the fleet by 0.3114km/h and the fleet could sail at the speed of 4.3km/h. So we can conclude that the average speed of ancient fleet without any influences of the seaward winds and tides was 3.98 km/h. We can make use of the various sailing speeds of ancient fleets when judging their maritime activities. If we make use of the various sailing speeds of the ancient fleets as calculated in this article, we will be able to get various important informations about the certain ancient fleet's maritime maneuver. For example, we can infer the sailing routs of a certain fleet and the time when the fleet passed a certain spot by making use of the various sailing speeds of the ancient fleet. In this article I did not take account of the shapes of ships that consist of the ancient fleets and the sizes of the various ships and fleets. It was because that such factors would not change the foresaid conclusions seriously.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.3
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• pp.149-158
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• 2015

In this study, we investigate tidal wave propagation characteristics, and classify regional tidal regime using tidal form number considered distribution of astronomical tide, overtides, and compound tides in the Han River Estuary, Gyeonggi Bay. The characteristics of the tidal wave propagation in main channels show dominance of major tidal constituents (e.g., $M_2$, $S_2$, $N_2$, $K_1$ and $O_1$) contributing to the astronomical tide however, distinct increasing of shallow water (e.g., $M_4$) and long period (e.g., $MS_f$) components toward up-estuary. Using the characteristics of tidal form number to astronomical tide, overtides, and compound tides, the regional tidal regime could be assorted into three regions. Firstly, a dominance area of astronomical tide was presented from open sea to a front of Incheon Harbor (Yeomha channel) and to north entrance of Seokmo channel. The area between south and north entrance of Yeomha channel and Ganghaw north channel classified into zone of showing strong shallow water components. It could be separated into upper estuary, upstream the Singok underwater dam, showed dominance of shallow overtides (e.g., $M_4$ and $MS_4$) water and long-term compound tides (e.g., $MS_f$) larger magnitude than astronomical tide. The shallow water components was earlier generated in lower part (south entrance) of Yeomha channel have strong bottom by effect of shallower and narrower compared with Seokmo channel. Tidal asymmetries of upper estuary cause by a development of overtides and compound tides are mainly controlled by influence of man-made structure.

• Magazine of the Korean Society of Agricultural Engineers
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• v.9 no.2
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• pp.1317-1322
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• 1967

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.111-116
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• 2004

We surveyed the coastal structure damages due to the typhoon 'Mae-mi' which heavily struck Korean peninsula in September 12, 2003. The survey revealed the typhoon induced high tides and strong winds were the main causes especially in Busan areas. Though some experimental real time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete systems should be implemented to save human lives and properties from huge typhoon disasters.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.4 no.2
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• pp.121-129
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• 1992

A two-dimensional numerical tidal model is formulated to reproduce tides in the northeastern Yellow-Sea, Seohan Bay. The model was formulated on spherical grid system with mesh resolution of 1' latitude by 4/3' longitude. As a first step, tidal distribution of four major tidal constituents are computed and compared with coastal observation. Independent tidal charts for the M$_2$, S$_2$, $K_1$, and $O_1$ tides were presented. Residual tidal currents and tidal energy flux were also computed.

• Journal of Environmental Science International
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• v.12 no.3
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• pp.345-358
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• 2003

Jindong bay at the northwestern part of Jinhae bay suffers from the occurrence of red tides in summer every year. In order to study the management methods of coastal environments, an ecological numerical model has been developed. The model experiments was forecasted that the load of nutrients from the land and field concentration will be cut down per 10% each. When we cut down 57.2% nitrogen load in the inner bay and 38.4% phosphorous load in the outer bay of bottom layer of the nutrients load from land and field concentration, the seawater quality standard levels up first grade. When we cut down 86.5% nutrients in the inner bay and 93.0% nutrients in the outer bay, the concentration of chlorophyll a decreases below 3.2 $\mu\textrm{g}$/(equation omitted)(an individual concentration of phytoplankton : 10,000cel1/ml), i.e. the red tides do not occur.