• Ocean and Polar Research
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• 제43권4호
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• pp.307-320
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• 2021

Udo Rhodolith Beach is a small-scale, mixed sand-and-gravel beach embayed on the N-S trending rocky coast of Udo, Jeju Island, South Korea. This study analyzes the short-term topographic changes of the beach during the extreme storm conditions of four typhoons from 2016 to 2020: Chaba (2016), Soulik (2018), Lingling (2019), and Maysak (2020). The analysis uses the topographic data of terrestrial LiDAR scanning and drone photogrammetry, aided by weather and oceanographic datasets of wind, wave, current and tide. The analysis suggests two contrasting features of alongshore topographic change depending on the typhoon pathway, although the intensity and duration of the storm conditions differed in each case. During the Soulik and Lingling events, which moved northward following the western sea of the Jeju Island, the northern part of the beach accreted while the southern part eroded. In contrast, the Chaba and Maysak events passed over the eastern sea of Jeju Island. The central part of the beach was then significantly eroded while sediments accumulated mainly at the northern and southern ends of the beach. Based on the wave and current measurements in the nearshore zone and computer simulations of the wave field, it was inferred that the observed topographic change of the beach after the storm events is related to the directions of the wind-driven current and wave propagation in the nearshore zone. The dominant direction of water movement was southeastward and northeastward when the typhoon pathway lay to the east or west of Jeju Island, respectively. As these enhanced waves and currents approached obliquely to the N-S trending coastline, the beach sediments were reworked and transported southward or northward mainly by longshore currents, which likely acts as a major control mechanism regarding alongshore topographic change with respect to Udo Rhodolith Beach. In contrast to the topographic change, the subaerial volume of the beach overall increased after all storms except for Maysak. The volume increase was attributed to the enhanced transport of onshore sediment under the combined effect of storm-induced long periodic waves and a strong residual component of the near-bottom current. In the Maysak event, the raised sea level during the spring tide probably enhanced the backshore erosion by storm waves, eventually causing sediment loss to the inland area.

• 한국해안·해양공학회논문집
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• 제31권2호
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• pp.73-87
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• 2019

파랑의 작용에 의해 유사가 이동되어 연안의 침식 퇴적이 일어나지만 상당히 비선형적이고 비정상적인 과정이므로, 파랑과 침식 퇴적의 상관성을 밝히고 예측하기는 쉽지 않다. 본 연구는 동해안에서 비디오 모니터링으로 얻은 5개 지점의 해빈폭 자료와 인근의 3개 지점의 파랑 모니터링 자료를 연계하여 상관성을 분석하였다. 전체 자료에 대한 상관분석에서는 유의미한 상관성이 없었지만, 기간 및 파랑 조건에 따른 상관분석에서는 주목할 만한 결과들이 제시되었다. 파고의 비초과확률이 약 99% 이상인 경우에는 주기와 해빈폭 변화 사이에 강한 음의 상관성이 있었으며, 주기의 비초과확률이 약 99% 이상인 경우에는 파고와 해빈폭 변화 사이에 강한 음의 상관성이 있었다. 주파향이 해안선 직각 방향과 인접한 경우, 주파향으로 입사하는 파랑에 대해 해빈폭이 확연히 감소하였다. 해빈폭과 파랑 사이에 뚜렷한 계절적 상관성이 나타나지는 않았으나, 태풍과 같은 특정 사건의 영향을 크게 받는 것으로 나타났다. 이러한 연구 결과의 실제 현장 적용을 위해서는 이와 같은 조건에 따른 상관 분석을 상세히 하여 해빈폭 변화 경향의 기준이 되는 파랑에 대해 더욱 정확한 정보를 얻을 필요가 있다.

• 대한지리학회지
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• 제37권5호
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• pp.511-521
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• 2002

해안사구는 지속적으로 변화하고 있다. 최근에는 지구온난화에 따른 해수면 상승 등의 이유로 재해대책의 차원에서 해수면 변화를 연구하는 것이 범세계적인 추세이다. 최근의 서해안 고속도로의 개통으로 서해안 사구 지역을 포함한 해수욕장을 찾는 사람은 계속 증가할 것으로 판단된다 하지만 해수면 상승에 따른 해안선 후퇴와 이에 따른 해안지역의 환경변화에 대한 국내의 관심은 매우 부족한 현실이다. 이 연구에서는 태안해안국립공원과 인근 지역의 사구에 대하여 1960년대부터 촬영된 항공사진과 최근의 헬기를 이용한 항공촬영 결과 및 고해상도 IKONOS 위성영상을 GIS 프로그램을 이용하여 시계열적으로 분석하여 사구 지역의 변화를 분석하였다. 특히 현지에서 1년 이상 지속적으로 31개 지점에서 모니터링한 자료를 분석하여 사구복원을 위해 설치된 모래울타리 및 보호 목책과 같은 시설물 및 식생복원의 효과를 분석하였다. 적극적인 복원대책의 효과가 긍정적으로 나타나고 있는 것으로 판단된다.

• 한국환경과학회지
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• 제24권1호
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• pp.31-46
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• 2015

In this study, the regional climate (WRF) and air quality (CMAQ) models were used to simulate the effects of future urban growth on surface ozone concentrations in the Seoul metropolitan region (SMR). These analyses were performed based on changes in ozone concentrations during ozone seasons (May-June) for the year 2050 (future) relative to 2012 (present) by urban growth. The results were compared with the impacts of RCP scenarios on ozone concentrations in the SMR. The fractions of urban in the SMR (25.8 %) for the 2050 were much higher than those (13.9 %) for the 2012 and the future emissions (e.g., CO, NO, $NO_2$, $SO_2$, VOC) were increased from 121 % (NO) to 161.3 % ($NO_2$) depending on emission material. The mean and daily maximum 1-h ozone in the SMR increased about 3 - 7 ppb by the effect the RCP scenarios. However, the effect of urban growth reduced the mean ozone by 3 ppb in the SMR and increased the daily maximum 1-h ozone by 2 - 5 ppb over the northeastern SMR and around the coastline. In particular, the ozone pollution days exceeding the 1-h regulatory standard (100 ppb) were far more affected by urban growth than mean values. As a result, the average number of days exceeding the 1-h regulatory standard increased up to 10 times.

• 한국컴퓨터정보학회논문지
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• 제17권10호
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• pp.61-69
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• 2012

삼면이 바다인 우리나라의 연안에 번식력과 포식성이 매우 강한 아무르불가사리의 개체수가 매년 급증하고 있다. 더욱이 아무르불가사리는 살아있는 어패류를 먹기 때문에 양식 어민들의 피해가 매우 크다. 따라서 불가사리를 구제하거나 불가사리의 개체수의 변화 및 이동 경로 파악 등을 위하여 수중 영상에서 불가사리 개체를 인식하는 기술은 매우 중요하다고 할 수 있다. 본 논문에서는 아무르불가사리의 형태적 특징 분석을 이용한 개선된 인식 방법을 제안하였다. 제안한 인식 방법은 아무르불가사리의 형태적 특징인 오목과 볼록에 대한 추출 정보가 부족한 경우를 위해 제안된 개선된 인식 방법이다. 바다 속에서 촬영되는 불가사리의 영상에서 불가사리의 형태적 특징을 모두 추출하는 것은 매우 어렵다. 따라서 제안하는 인식 방법은 다양한 아무르불가사리 영상에서 개체를 인식하는데 효과적이다. 실험결과, 제안한 기법의 인식률은 92.5%로 기존 기법보다 우수한 성능을 보였다.

• 건축역사연구
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• 제9권1호
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• pp.27-46
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• 2000

This study aims at examining the background and development process of Masan city after Koryo Dynasty, making a reconstructive map of Original Masan using the first registration maps made in 1912 and analyzing the urban structure of the Original Masan area. The origin of Masan city went back to Koryo dynasty. Around 1040 Koryo government placed an official shipping facility in Masan to transport the taxed grain to the capital city. After that Masan became an important port covering the southern part of KyungSang-Do. And the urbanization of the Original Masan began to bud after a shipping facility was again established by the Chosun Dynasty in 1760 and strengthened in the 19th century after the social standing system was broken and many peasants moved to cities as daily workers. In 1899 Masan was forced to be opened to foreign powers and they placed an international settlement distanced from the area(Original Masan). After this many Japanese advanced to the international settlement and further to the area. The advancement of Japanese brought a critical change in the urban structure of the area. Land was owned by Japanese and many modern sysytems were introduced such as modern buildings, new roads, railroad and modern factories. According to the reconstructive map of the area, 80.5% of land lots are less than $200m^2$ showing the size of each land lot is comparatively small. And Japanese occupied 31.5% of the land in the area. Their land was located on the stratigic points near the port and the center of commerce. The ratio of the road area to the whole land was around 14%, not so low for urban areas in that time. The reconstructive map reveals the exact coastline of the year 1912 erased now due to filling the sea and extending the land, Present Masan city has been developed having the Original Masan as its nucleus. The area has been always the center of urban activities for Masan city. Making an exact reconstructive map for the area and analyzing the urban structure of the area in 1912 is a very important work to understand Masan city wholy.

• 한국수산과학회지
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• 제25권6호
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• pp.457-473
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• 1992

양향성 대륙붕에서 1차 파동방정식은 양 해안경계에서의 바람응력과, 대륙붕폭에 걸친 바람응력의 회전효과를 갖는다. 황해에서 바람응력 회전효과는 대륙붕파를 발생시키는 힘으로서 무시될 수 있다. 켈빈파는 대륙붕파보다 약화될 때까지의 거리가 매우 크기 때문에 황해 북쪽만(별)을 거의 약화되지 않고 통과할 수 있다. 파동특성을 따라 적분하는 수치방법은 반대방향으로 전파되는 파동을 수용하기 위해 조절되었다. 보다 실제와 가까운 해안선을 사용한 결과, 모델재생이 해류에서는 개선되었으나 해수면에서는 거의 개선되지 않았다. 이것은 해수면을 주로 결정하는 켈빈파가 해저지형의 변화에 영향을 극히 적게 받음을 의미한다 보다 개선된 해수면 재생을 위해서는 동지나 해에서 황해로 전파되는 켈빈파의 에너지를 알 필요가 있다. 해안을 따른 순풍류와 골을 따른 역풍류의 기본구조는 계절풍에 의해 발생하는 황해의 계절순환을 뒷받침한다.

• Ocean and Polar Research
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• 제36권2호
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• pp.87-101
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• 2014

Recently, more attention has been paid to the geomorphological changes in the Nakdong River Estuary, because those changes are caused by artificial activities including weirs, reclamation and construction. In order to analyze quantitatively the recent geomorphological variability in the Nakdong River Estuary, we surveyed the depth and elevation of submarine topography near Jinwoodo and Sinjado from March 2007 to February 2012. A statistical method (based on Digital Shoreline Analysis System) and an Empirical Orthogonal Functions method were used to evaluate the morphological changes. According to the statistical variables (DCE, NDC, EPR, LRR), the highest amount and rate of accumulation were recorded around the Gadeokdo whereas the greatest amount of erosion appeared around the coast off the eastern part of Sinjado. In particular, a dynamic variation of morphology was clearly observed in the vicinity of the sub-tidal channel located between Jinwoodo and Sinjado, which seems to be attributable to channel migration. As a result of the EOF method, the first mode (48.7%) is most closely related to the pattern of morphological variability that might be associated with the westerly movement of sediment by longshore current. The spatial variability of the second mode (16.6%) was high in the shoreface of Sinjado, showing a 4-year periodicity of temporal variability. The strong correlation (coefficient 0.73) between the time coefficient and suspended sediment discharge from Nakdong River emphasizes the role of sediment discharge to deposition in this area. The spatial variability of the third mode (11.3%) was distributed mainly around the coast off the eastern part of Sinjado, which is related to the movement of the coastline of Sinjado. Based on the last 5 year's data, our results suggest that the study area is characterized on the whole by a depositional pattern, but the extent of sedimentation is different locally.

• 한국측량학회지
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• 제35권2호
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• pp.113-122
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• 2017

Natural disasters caused by climate change are increasing globally. There are few studies on the quantitative analysis methods for predicting damages in the island area due to sea level rise. Therefore, it is necessary to study the damage prediction analysis method using the GIS which can quantitatively analyze. In this paper, we analyze the cause and status of sea level rise, quantify the vulnerability index, establish an integrated terrestrial modeling method of the ocean and land, and establish a method of analyzing the damage area and damage scale due to sea level rise using GIS and the method of making the damage prediction figure was studied. In order to extract the other affected areas to sea level rise are apart of the terrain model is generated by one requires a terrain modeling of target areas are offshore and vertical reference system differences in land, found the need for correction by a tidal observations and geoid model there was. Grading of terrain, coastline erosion rate, coastal slope, sea level rise rate, and even average by vulnerable factors due to sea level rise indicates that quantitative damage prediction is possible due to sea level rise in the island area. In the case of vulnerable areas extracted by GIS, residential areas and living areas are concentrated on the coastal area due to the nature of the book area, and field survey shows that coastal changes and erosion are caused by sea level rise or tsunami.

• 한국농공학회논문집
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• 제51권2호
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• pp.59-67
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• 2009

A study on fugitive dusts was conducted at Saemangeum reclaimed land located in Gim-je area. The monitoring result on the fugitive and suspended dust was significantly affected by the farming activities (harvesting and land cultivation) and vehicles passing nearby the measuring points. The concentration of the fugitive dust generated from the reclaimed land was reduced remarkably by the effect of halophyte present on the ground and the tide embankment. Comparing the data collected in 2006 and 2007, the concentrations of TSP and PM10 decreased by 47.4% and 29.5%, respectively. After harvesting operations at paddy field, TSP increased by 22% while PM10 increased by 54%. The concentration of a Cl- which is a representative ion of sea-salt decreased to about 35% in 2007 compared with 2006. This represents that the inside area change and plant covering rate affected on the decrease of fugitive dust. The correlation analysis for the compounds of topsoil at each measuring point shows that near the coastline is more comparable. The canopy of halophyte in the source area also increased which reduced the fugitive dust remarkably. The dust distribution measured by dust spectrometer at the same point shows that most particles are $0.5{\mu}m$ to 2um size but not greater than $5{\mu}m$.