• (The) Research of the performance art and culture
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• no.32
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• pp.399-426
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• 2016

Sanjo has a quintessential value not only because of its musical depth but also because of its style of music that best expresses Korean sentiment. However, new values are being established from different viewpoints as time passes so Sanjo's values need a modification in order to encompass a contemporary value that is required and accepted by modern society. In this context, while focusing on communication with the public, I contemplated the developmental direction of Sanjo in five perspectives; The Social realization of value, The Experimental and social transformation, The Social diffusion of creation, The Leap of fusion and harmony and finally The Socialization of contents. In the perspective of 'social realization of value', Sanjo refers to creative activity as a new 'duneum' which allows traditional and creative activity to deviate freely while still being under the Sanjo guideline. Either way, it has a periodical value because new forms with new rhythms are the only ways to communicate with the modern public. When these values can be understood by modern society can Sanjo be revived and be acknowledged as an infinite value. Secondly as an experiment and social transformation, there is a transformation of musical instruments in the 21th century. Our musical instruments should be transformed to effectively perform our music rather than to perform Western music. Third, social diffusion of creation should be the 'new Sanjo festival in 21th century' which can facilitate the communication with the public. Fourth, regarding leap of fusion and harmony, I suggest a performing culture consisting of 'Storytelling Sanjo' and 'Media Art' which will ceaselessly evolve Sanjo performance as a medium to communicate with the public. Finally, in regards to the socialization of contents, I emphasize that Sanjo should have contents of mass media as a way of means to help utilize mass media.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.594-604
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• 2021

To evaluate the causes of beach erosion in Sinji-Myeongsasimni Beach, external forces, such as tides, tidal currents, and waves, were observed seasonally from March 2019 to March 2020, and the surface sediments were analyzed for this period. In addition, the shoreline positions and beach elevations were regularly surveyed with a VRS GPS and fixed-wing drone. From these field data, the speed of the tidal currents was noted to be insufficient, but the waves were observed to af ect the deformation of the beach. As the beach is open to the southern direction, waves of heights over 1 m were received in the S-SE direction during the spring, summer, and fall seasons. Large waves with heights over 2 m were observed during typhoons in summer and fall. Because of the absence of typhoons for the previous two years from July 2018, the beach area over datum level (DL) as of July 2018 was greater by 30,138m² compared with that of March 2019, and the beach area as of March 2020 decreased by 61,210m² compared with that of March 2019 because of four typhoon attacks after July 2018. The beach volume as of March 2019 decreased by 5.4% compared with that of July 2018 owing to two typhoons, and the beach volume as of September 2019 decreased by 7.3% because of two typhoons during the observation year. However, the volume recovered slightly by about 3% during fall and winter, when there were no high waves. According to the sediment transport vectors by GSTA, the sediments were weakly influxed from small streams located at the center of the beach; the movement vectors were not noticeable at the west beach site, but the westward sediment transport under the water and seaward vectors from the foreshore beach were prominently observed at the east beach site. These patterns of westward sediment vectors could be explained by the angle between the annual mean incident wave direction and beach opening direction. This angle was inclined 24° counterclockwise with the west-east direction. Therefore, the westward wave-induced currents developed strongly during the large-wave seasons. Hence, the sand content is high in the west-side beach but the east-side beach has been eroded seriously, where the pebbles are exposed and sand dune has decreased because of the lack of sand sources except for the soiled dunes. Therefore, it is proposed that efforts for creating new sediment sources, such as beach nourishment and reducing wave heights via submerged breakwaters, be undertaken for the eastside of the beach.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.859-868
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• 1998

In order to investigate the relation between the marine environmental characteristics and the change of the catch in set net, the marine environment properties were analyzed by temperature and salinity observed in the western coastal area of Cheju Island from 1995 to 1996 and the results are as follows 1) Main axis of Tsushima Current appeared in the western coastal area of Cheju Island was off 2$\~$3 miles from November to May. Therefore the waters of high temperature over $14^{\circ}C$ and high salinity from $34.40\%_{\circ}$ to $34.60\%_{\circ}$ were distributed homogeneously from surface to bottom in this time. But China Coastal Waters of low salinity appeared in the Cheju Strait from June to October, surface waters became of high temperature and low salinity, and middle and bottom waters became of the temperature from 11 to $14^{\circ}C$ and the salinity over $33.50\%_{\circ}$ and then vertically sharp thermocline and halocline are formed in the western coastal area of Cheju Island. In summer, the water temperature and salinity of the surface waters in wstern coastal area of Cheju Island were lower and higher respectively than that in middle area of the Cheju Strait and the temperature and salinity of the bottom waters in this area were higher and lower, respectively than that in middle area of the Cheju Strait. Such a distribution shows a tidal front in this coastal area. On the whole year, surface temperature and salinity were from 14 to $23^{\circ}C$ and from 30.60 to $34.60\%_{\circ}$, respectively, and annual fluctuation range of temperature and salinity was within $9^{\circ}C$ and $4.00\%_{\circ}$, respectively, Thus, annual fluctuation range in this area is much narrower than that in the Cheju Strait. In bottom water, temperature ranges from 14 to $20^{\circ}C$ through the year. Thus, the fluctuation range of temperature is narrow. The low temperature of from $11^{\circ}C$ to $13^{\circ}C$ appeared in the west enterance of Cheju Strait was not shown in this coastal area. 2) The salinity of bottom water was from $33.60\%_{\circ}$ to $34.40\%_{\circ}$ in 1995, while low salinity wale. below $32.00\%_{\circ}$ appeared all depth from June in 1996. Thus, the variation of hydrographic conditions in this area is narrow in winter, and wide in summer due to the influence of China Coastal Waters. 3) In summer, surface cold water, local eddy and fronts of temperature and salinity were showed within 2 mile from the west coast of the Cheju Island due to vertical mixing by tidal current. Especially, temperature and salinity of bottom water are changed with the change of depth around Biyang-Do. Thus, the front of temperature and salinity appeared clearly between shallow area with the depth of under 10 m and deep area with of the depth of more than 50m. Surface water in outside area where high temperature and low salinity water appear intrudes between Worlreong-Ri and Geumreung-Ri. Thus, the front of temperature and salinity was made along the line that connects from this coast to Biyang-Do, The temperature of the bottom water is $2^{\circ}C$ to $4^{\circ}C$ lower than that of the surface water and its salinity is $0.02\%_{\circ}$ to $0.08\%_{\circ}$ higher than that of the surface water even in shallow area.

• Economic and Environmental Geology
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• v.45 no.3
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• pp.317-333
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• 2012

The Yeongweol Group is a Lower Paleozoic mixed carbonate-siliciclastic sequence in the Taebaeksan Basin of Korea, and consists of five lithologic formations: Sambangsan, Machari, Wagok, Mungok, and Yeongheung in ascending order. Sequence stratigraphic interpretation of the group indicates that initial flooding in the Yeongweol area of the Taebaeksan Basin resulted in basal siliciclastic-dominated sequences of the Sambangsan Formation during the Middle Cambrian. The accelerated sea-level rise in the late Middle to early Late Cambrian generated a mixed carbonate-siliciclastic slope or deep ramp sequence of shale, grainstone and breccia intercalations, representing the lower part of the Machari Formation. The continued rise of sea level in the Late Cambrian made substantial accommodation space and activated subtidal carbonate factory, forming carbonate-dominated subtidal platform sequence in the middle and upper parts of the Machari Formation. The overlying Wagok Formation might originally be a ramp carbonate sequence of subtidal ribbon carbonates and marls with conglomerates, deposited during the normal rise of relative sea level in the late Late Cambrian. The formation was affected by unstable dolomitization shortly after the deposition during the relative sea-level fall in the latest Cambrian or earliest Ordovician. Subsequently, it was extensively dolomitized under the deep burial diagenetic condition. During the Early Ordovician (Tremadocian), global transgression (viz. Sauk) was continued, and subtidal ramp deposition was sustained in the Yeongweol platform, forming the Mungok Formation. The formation is overlain by the peritidal carbonates of the Yeongheung Formation, and is stacked by cyclic sedimentation during the Early to Middle Ordovician (Arenigian to Caradocian). The lithologic change from subtidal ramp to peritidal facies is preserved at the uppermost part of the Mungok Formation. The transition between Sauk and Tippecanoe sequences is recognized within the middle part of the Yeongheung Formation as a minimum accommodation zone. The global eustatic fall in the earliest Middle Ordovician and the ensuing rise of relative sea level during the Darrwillian to Caradocian produced broadly-prograding peritidal carbonates of shallowing-upward cyclic successions within the Yeongheung Formation. The reconstructed relative sea-level curve of the Yeongweol platform is very similar to that of the Taebaek platform. This reveals that the Yeongweol platform experienced same tectonic movements with the Taebaek platform, and consequently that both platform sequences might be located in a body or somewhere separately in the margin of the North China platform. The significant differences in lithologic and stratigraphic successions imply that the Yeongweol platform was much far from the Taebaek platform and not associated with the Taebaek platform as a single depositional system. The Yeongweol platform was probably located in relatively open shallow marine environments, whereas the Taebaek platform was a part of the restricted embayments. During the late Paleozoic to early Mesozoic amalgamations of the Korean massifs, the Yeongweol platform was probably pushed against the Taebaek platform by the complex movement, forming fragmented platform sequences of the Taebaeksan Basin.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.4
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• pp.153-178
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• 2018

Most operational uses of wind speed data require measurements at, or estimates generated for, the reference height of 10 m above mean sea level (AMSL). On the Ieodo Ocean Research Station (IORS), wind speed is measured by instruments installed on the lighthouse tower of the roof deck at 42.3 m AMSL. This preliminary study indicates how these data can best be converted into synthetic 10 m wind speed data for operational uses via the Korea Hydrographic and Oceanographic Agency (KHOA) website. We tested three well-known conventional empirical neutral wind profile formulas (a power law (PL); a drag coefficient based logarithmic law (DCLL); and a roughness height based logarithmic law (RHLL)), and compared their results to those generated using a well-known, highly tested and validated logarithmic model (LMS) with a stability function (${\psi}_{\nu}$), to assess the potential use of each method for accurately synthesizing reference level wind speeds. From these experiments, we conclude that the reliable LMS technique and the RHLL technique are both useful for generating reference wind speed data from IORS observations, since these methods produced very similar results: comparisons between the RHLL and the LMS results showed relatively small bias values ($-0.001m\;s^{-1}$) and Root Mean Square Deviations (RMSD, $0.122m\;s^{-1}$). We also compared the synthetic wind speed data generated using each of the four neutral wind profile formulas under examination with Advanced SCATterometer (ASCAT) data. Comparisons revealed that the 'LMS without ${\psi}_{\nu}^{\prime}$ produced the best results, with only $0.191m\;s^{-1}$ of bias and $1.111m\;s^{-1}$ of RMSD. As well as comparing these four different approaches, we also explored potential refinements that could be applied within or through each approach. Firstly, we tested the effect of tidal variations in sea level height on wind speed calculations, through comparison of results generated with and without the adjustment of sea level heights for tidal effects. Tidal adjustment of the sea levels used in reference wind speed calculations resulted in remarkably small bias (<$0.0001m\;s^{-1}$) and RMSD (<$0.012m\;s^{-1}$) values when compared to calculations performed without adjustment, indicating that this tidal effect can be ignored for the purposes of IORS reference wind speed estimates. We also estimated surface roughness heights ($z_0$) based on RHLL and LMS calculations in order to explore the best parameterization of this factor, with results leading to our recommendation of a new $z_0$ parameterization derived from observed wind speed data. Lastly, we suggest the necessity of including a suitable, experimentally derived, surface drag coefficient and $z_0$ formulas within conventional wind profile formulas for situations characterized by strong wind (${\geq}33m\;s^{-1}$) conditions, since without this inclusion the wind adjustment approaches used in this study are only optimal for wind speeds ${\leq}25m\;s^{-1}$.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.67-85
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• 2007

A three-dimensional hydrodynamic model with the fine grid is applied to simulate the barotropic tides, tidal currents, residual currents and salinity dispersions in the Yellow Sea and the East China Sea. Data inputs include seasonal hydrography, mean wind and river input, and oceanic tides. Computed tidal distributions of four major tides($M_2,\;S_2,\;K_1$ and $O_1$) are presented and results are in good agreement with the observations in the domain. The model reproduces well the tidal charts. The tidal residual current is relatively strong around west coast of Korea including the Cheju Island and southern coast of China. The current by $M_2$ has a maximum speed of 10 cm/s in the vicinity of Cheju Island with a anti-clockwise circulation in the Yellow Sea. General tendency of the current, however, is to flow eastward in the South Sea. Surface residual current simulated with $M_2$ and with $M_2+S_2+K_1+O_1$ tidal forcing shows slightly different patterns in the East China Sea. The model shows that the southerly wind reduces the southward current created by freshwater discharge. In summer during high runoff(mean discharge about $50,000\;m^3/s$ of Yangtze), low salinity plume-like structure(with S < 30.0 psu) extending some 160 km toward the northeast and Changjiang Diluted Water(CDW), below salinity 26 psu, was found within about 95 km. The offshore dispersion of the Changjiang outflow water is enhanced by the prevailing southerly wind. It is estimated that the inertia of the river discharge cannot exclusively reach the around sea of Cheju Island. It is noted that spatial and temporal distribution of salinity and the other materials are controlled by mixture of Changjiang discharge, prevailing wind, advection by flowing warm current and tidal current.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.513-523
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• 2017

We evaluated the viability of phytoplankton along the salinity gradient in the flood and ebb tides of spring tide of February and the ebb tide of neap tide of March 2017 in the Seomjin River Estuary. Additional laboratory experiments were also conducted to determine the reason of the pH changes along the salinity gradient using the field natural sample in February. In field, saltwater was well mixed at downstream vertically and the salinity gradient was horizontally appeared toward upstream of freshwater zone. There were strong negative correlations between salinity and nutrient (nitrate + nitrite R=0.99, p<0.001, and silicate R=0.98, p<0.001), implying that those two nutrients of freshwater origin were gradually diluted with mixing the saltwater. On the other hands, relatively high phosphate concentration was kept in the stations of saltwater over 15 psu, indicating that it was caused by resuspended sediments of Gwangyang Bay and downstream by tidal water mixing.Among phytoplankton community structure in winter, Eucampia zodiacus have occupied to be c.a. 70 % in the most stations. Based on the field survey results for survivability of phytoplankton by phytoPAM instrument, there was positive correlations between salinity and chlorophyll a (R=0.82, p<0.001) and, salinity and active chlorophyll a (R=0.80, p<0.001), implying that the dominant marine diatom species may have significantly damaged in low salinity conditions of upstream. Also, maximum mortality rate of phytoplankton caused by low salinity shock was appered to be 75% in the upstream station. In particular, the pH in spring tides of February had tended to increase with high phytoplankton accmulated stations, suggesting that it was related with absorption of $CO_2$ by the photosynthesis of dominant diatom. In laboratory experiments, phytoplankton mass-mortality caused by low salinity shock was also occurred, which is confirmed with reducing the photosynthetic electron transport activity. Following the phytoplankton mass-mortality, bacteria abundance was significantly increased in 24 hours. As a result, the mass-proliferating bacteria can produce the $CO_2$ in the process of biodegradation of diatoms, which can lead to pH decrease. Therefore, marine phytoplankton species was greatly damaged in freshwater mixing area, depending on along the salinity gradient that was considered to be an important role in elevating and reducing of pH in Seomjin River Estuary.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.308-311
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• 2007

황해의 25개 조사정점의 표층수에 대한 해양환경요인 및 식물플랑크톤 현존량의 월별 조사결과를 종합하여 주성분분석(PCA)을 실시한 결과 주성분 I에서는 변화를 26.6% 설명할 수 있으며, 이중 질산질소가 가장 많이 기여하였고, 이어서 용존무기질소, 규산규소, 수온, 용존산소, 암모니아질소 순으로 기여 하고 있었다. 주성분 II에서는 20.3%를 설명 할 수 있으며, 이중 용존산소가 가장 많이 기여하였고 그 외 엽록소 a, 수온, 염분, 규산규소, 식물플랑크톤 현존량 순으로 기여 하였다. 주성분 III에서는 15.1%를 설명 할 수 있으며, 이중 인산인이 가장 많이 기여하였고 그 외 염분, 아질산질소, 수온, 용존산소, 질산질소, 용존무기질소 순으로 기여하였다. PCA에 이용된 항목 중 부유물질은 제외한 모든 항목은 주성분 I, II, III에 5%이하 유의수준에서 의미 있는 상관성이 있었다. 주성분 I은 질산성질소, 용존무기질소, 규산규소, 인산인과는 긍정적인 상관성(p<0.0001)을 갖고, 수온, 암모니아질소와는 부정적인 상관성을 보였다(p<0.001). 주성분 II에서는 용존산소, 엽록소 a, 식물플랑크톤 현존량은 긍정적 상관성을 나타내었고, 수온, 염분, 규산규소와는 부정적인 상관성을 보였으며(p<0.0001), 주성분 III에서는 염분, 수온, 질산질소, 용존무기질소, 식물플랑크톤 현존량과는 긍정적인 상관성(P<0.0001)을 나타내었고 인산인, 아질산질소, 용존산소는 부정적인 상관성을 나타내었다 (p<0.01). 공간적인 분포특성은 조사정점에 따라 항목별 결과에 대한 분산이 커서 일정한 특성을 도출하기가 어려운 상태이나 대체로 PCA II축을 기준으로 상부인 $1/4{\sim}2/4$분면에 북부와 중부의 조사정점이 위치하고 음의 방향인 $3/4{\sim}4/4$분면에 중부와 남부의 조사정점이 위치하고 있어 북측의 307선과 308선 및 중부의 309선과 310선 그리고 남측의 311선과 312선으로 구분되어지는데 그 중에서 태안반도의 연안역인 307선의 03점은 계절에 변화가 가장 커서 분산의 폭이 심한 상태로서 다른 조사정점들과 구분되어진다. 전반적으로 북측해역에서는 용존산소, 엽록소 a, 식물플랑크톤 현존량이 남측해역에 비해 상대적으로 많은 반면, 남측해역은 수온과 염분 및 규산규소가 높은 상태이었다. 북쪽인 307선과 308선은 연안역과 외해에서 상대적으로 영양염류가 높았으며, 중부인 309선과 310선은 연안역과 준 외해역인 07점과 09점에서 영양염류가 높았었고, 남부 해역인 311선과 312선에서는 연안역에서 영양염류가 상대적으로 높은 경향을 나타내었다. 즉 황해 동부는 연안역에서는 조석간만의 차가 심하고, 새만금 및 시호호등과 같은 대규모의 간척 매립으로 육상의 오염원이 자정작용을 거치지 못하고 직접 연안으로 유입되고 있는 실정이다. 또한 10여 년 전부터 육지의 모래부족으로 다량의 바다 모래가 채취되어 왔고 그 량이 점차 증가추세이며, 중부외해역에서는 각종 폐기물 투기로 점차 영양염류의 부하량이 증가되고 있어 특히 질소계와 인의 영양염류 농도가 높아지고 있는 추세이다. 시간적 변동특성은 전반적으로 순환하는 형태를 유지하고 있다. 2005년 2월에는 질산질소, 용존무기질소, 규산규소, 인산인, 용존산소가 높았었으며 4월로 접어들면서 항목 간에 분산되는 경향을 보이면서 수온, 엽록소 a 및 식물플랑크톤이 증가 하면서 해역에 따라 좌우로 분산되는 경향을 나타내었고 6월에는 아질산질소를 제외한 영양염류가 감소하는 경향을 보였다. 8월에는 6월에 비해 수온이 높아지고 규산규소, 질산질소, 용존무기질소 등이 약간 증가추세이었으며 10월로 접어들면서 증가추세가 더 높아졌었고 12월에는 질산질소, 용존무기질소, 규산규소, 인산인, 용존산소가 높아졌었다. 2006년 4월에는 2005년 4월에 비해 수온, 엽록소 a, 식물플랑크톤의 현존량이 높아져서 전년 동시기와 약간 다른 양상을 보이고 있었다. 즉 동계인 2월을 시작으로 반 시계 또는 시계 방향으로 순환하는 형태를 유지하고 있으며, 4월은 2개년 비교해 보았을 때 해마다 해양환경에 따라 그 순환 정도 및 형태가 다를 것으로 추정된다.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.524-540
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• 2013

After the construction of the Geum River estuary dam, we investigated the ecological property of phytoplankton community with physicochemical property in 9 stations of Geum River estuary 4 times seasonally in 2010 about the environmental changes through the change of phytoplankton. Physicochemical property seems to show eutrophication which developed from the tendency of accruing of the nutrients (those involved in intermittency of freshwater which flows from the dike and the surrounding cities), caused by the changing of tidal flow, the decreasing of the inflow of seawater after the construction of the Geum River estuary dam (dike). A total of 233 species of species composition of phytoplankton emerged, showing a highly increased result compared to that of the former research. The reason for the increase in number is considered as a phenomenon resulting from the mix of blackish and freshwater marine species in the flow of intermittency of freshwater discharge. Also, the standing crops of phytoplankton considerably increased compared to when the dike had not yet been built. Highly affected by the discharge of occasional freshwater, the diatoms of blackish water zone dominated in spring and winter, while freshwater species appeared to dominate in summer and autumn. The species diversity showed over 2.0 except in winter season. After a cluster analysis, the result showed that the Geum River estuary was influenced by runoff from cities like Gunsan, the sewage which flows from Gyeongpo River, and the intermittency of freshwater discharge from the Geum River estuary dam.

• Journal of Korea Water Resources Association
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• v.48 no.12
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• pp.1065-1075
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• 2015

In the estuary where the structure such as river-mouth weir has been installed, the flow is developed very complicatedly due to river water from upstream, tide of the sea and floodgate operation. Especially, if basin outlets more than one exists in one estuary, the boundary conditions will be significantly more complex form. Saemangeum(SMG) project area in Korea is the most typical example. There are Mankyung river and Dongjin river in upstream. The water of them inflows into SMG project area. In the downstream, river flow was drained from inland to sea over the SMG sea dike through the sluice. The connecting channel was located between Mankyung and Dongjin basins. It functions not only as transportation by ship in ordinary period but also as flood sharing by sending flood flow to each other in flood period. Therefore, in order to secure the safety against flood, it is very important to understand the flood sharing capacity for connecting channel. In this study, the flood control effect was analyzed using numerical simulation. Delft3D was used to numerical simulation and simulated period was set up with neap tide, in which the maximum flood stage occurred due to poor drainage. Actually, three connecting channels were designed in land use plan of the SMG Master Plan, but they were simplified to a single channel for conciseness of analysis in this study. According to the results of numerical analysis, the water level difference between two basins was increased and the maximum flood stage at dike sluice was also upraised depending on decrease of conveyance. And the velocity induced by same water level difference was decreased when the conveyance became smaller. In certain conveyance above, there was almost no flood control effect. Therefore, if the results of this study are considered for design of connecting channel, it will be expected to draw the optimal conveyance for minimizing dredging construction cost while maximizing the flood control effect.