소청초 종합해양과학기지 Radar 파랑 관측 데이터의 신뢰도 향상

민용침(Yong chim Min),정진용(Jin Yong Jeong),심재설(Jae Seol Shim),도기덕(Ki deok Do) 한국연안방재학회 2017 한국연안방재학회지 Vol.4 No.4

Ocean Research Stations (ORSs) is the ocean platform type observation towers and measured oceanic, atmospheric and environmental data. These station located on the offshore area far from the coast, so they can produce the data without land effect. This study focused to improve the wave data quality of ORS station. The wave observations at ORSs are used by the C-band (5.8 GHz, 5.17 cm) MIROS Wave and Current Radar (MWR). MWR is convenient to maintenance and produce reliability wave data under bad weather conditions. MWR measured significant wave height, peak wave period, peak wave direction and 2D wave spectrum, so it’s can provide wave information for researchers and engineers. In order to improve the reliability of MWR wave data, Datawell Waverider Buoy was installed near the one ORS (Socheoncho station) during 7 months and validate the wave data of MWR. This study found that the wave radar tend to be overestimate the low wave height under wind condition. Firstly, this study carried out the wave Quality Control (QC) using wind data, however the quality of wave data was limited. So, this study applied the four filters (Correlation Check, Direction Filter, Reduce White Noise and Phillips Check) of MWR operating software and find that the filters effectively improve the wave data quality. After applying 3 effective filters in combination, the RMSE of significant wave height decreased from 0.81m to 0.23m, by 0.58m and Correlation increased from 0.66 to 0.96, by 0.32, so the reliability of MWR significant wave height was significantly improved.

소청초 종합해양과학기지 원격제어·관측시스템 구현

민인기(Min, In Ki),정진용(Jeong Jin Yong),정종민(Jeong, Jong Min),민용침(Min, Yong Chim),심재설(Shim, Jae Seol) 한국연안방재학회 2015 한국연안방재학회 학술발표대회 논문집 Vol.2015 No.-

세 번째 해양과학기지인 소청초 종합해양과학기지가 건설되어 시범 운영중에 있다. 소청초 기지에는 기상, 해양, 환경 등의 관측장비, 등대, 디젤발전기와 복합 발전기, 침입자 감시장비 등이 설치되어 운영되고 있다. 이들 장비 및 설비는 원격 관측 및 제어가 가능하도록 설계와 시스템 구축이 이루어져 있으며 이를 통해 얻어지는 데이터는 위성통신망을 통해 육상 운영사무실과 송·수신이 가능하도록 시스템이 구현되어 있다. 육상에는 전송된 데이터가 안정적으로 저장, 활용될 수 있도록 서버가 설치되어 운영되고 있으며, 실시간 기반으로 기지의 모든 설비 및 장비상태를 감시하고 필요 시 원격제어할 수 있도록 기능이 갖추어져 있다.

해양과학기지 원격 파랑 관측 자료의 품질 향상을 위한 응용기술 개발

도기덕,민용침,심재철,Do, Gi-Deok,Min, Yong-Chim,Sim, Jae-Cheol 한국수자원학회 2020 물과 미래(한국수자원학회지) Vol.53 No.1

공극매체에서의 파동장에 대한 Boussinesq 방정식의 유도 및 적용

전인식,민용침,임학수,Chun, Insik,Min, Yongchim,Lim, Hak-Soo 대한토목학회 2015 대한토목학회논문집 Vol.35 No.5

공극매체에서의 파동장을 해석할 목적으로 공극매체 흐름에 대한 Reynolds 이송정리를 적용하여 공극매체에서의 Navier-Stokes 방정식을 유도하였으며 기존의 연구들과 비교하였다. 또한, 이 N-S 방정식을 이용하여 공극매체 내외에서 파동장의 비선형성과 분산성을 적절히 재현하기 위한 확장형 Boussinesq 방정식을 유도하였다. 이들 방정식의 정확도를 검증하기 위하여 공극방파제의 반사율과 투과율에 대한 수치해석을 수행하여 그 결과를 기존의 수리실험결과들과 비교하였다. 수치해석결과는 토립자의 가상질량계수에 민감하게 반응하였으며 계수를 영으로 처리했을 때 수리실험결과와 비교적 잘 일치하는 것으로 나타났다. In the present study, the Navier-Stokes (N-S) equations delineating water flows inside porous media were derived applying Reynolds transport theorem in order to provide a basis for analyzing water wave problems inside the porous media. Then, the derived N-S equations were compared with the same species of equations in existing researches. Based on the N-S equations, a set of Boussinesq equations was then derived in such a form that the dispersiveness and nonlinearity of water waves inside the porous media can be properly reproduced. Finally, numerical analyses were carried out to demonstrate the validity of the equations. The reflection and transmission coefficients of porous breakwaters were calculated and compared with the results of existing hydraulic experiments. The numerical results showed a rather sensitive dependency on the virtual mass coefficient of grains constituting the porous media. The selection of the coefficient with zero turned out to give nice agreements with numerical and experimental results.

비디오 이미지를 이용한 백파 관측기법 개발

김선신(Kim, Sun-Sin),민용침(Min, Yong-Chim),정종민(Jeong, Jong-Min),정진용(Jeong, Jin-Yong),유제선(Yoo, Je-Seon),심재설(Shim, Jae-Seol) 한국연안방재학회 2015 한국연안방재학회 학술발표대회 논문집 Vol.2015 No.-

백파는 해양과 대기의 기체 및 에너지 교환의 중요한 변수로써 해양의 중요한 관측 항목 중 하나이다. 이어도 종합해양과학 기지에서 해상 상태를 관찰하기 위하여 4대의 CCTV를 이용한 비디오 모니터링 시스템을 구축하여 2014년 11월부터 운영 중에 있다. 본 연구에서는 비디오 이미지를 이용한 백파 관측을 시도하였으며 세부적으로 백파 발생 시 pixel 강도의 특성을 파악하고 이를 기반으로 백파 관측기법을 수립하여 이어도 해역에 적용하였다.

독도 MIROS Wave Radar를 이용한 파랑관측 및 품질관리

전현정(Hyunjung Jun),민용침(Yongchim Min),정진용(Jin-Yong Jeong),도기덕(Kideok Do) 한국해안해양공학회 2020 한국해안해양공학회 논문집 Vol.32 No.2

해양에서의 파랑관측은 부이나 압력계 등을 이용하여 수면변위를 관측하는 직접관측방법과 Radar를 이용하여 관측하는 원격관측방법으로 구분된다. 직접관측방법은 정확도가 높지만, 악기상 시 파손 및 유실 위험이 크며 외해 설치 시 많은 유지 보수비용이 필요하다는 단점을 가지고 있다. 반면 Radar와 같은 원격관측방법은 장비를 육지에 계류하여 유지관리가 용이하지만 직접관측방법과 비교하면 정확도가 다소 낮은 단점이 있다. 본 연구에서는 원격파랑관측자료의 품질을 개선하기 위해 독도에 설치되어 운영 중인 MIROS Wave and Current Radar(MWR) 관측자료의 수집 및 분석을 하였으며, 이를 기상청에서 운영 중인 해양파고부이(CWB)의 관측자료와 비교하였다. 그리고 MWR 관측자료의 품질을 개선하기 위해 1) MIROS사에서 개발한 필터(Reduce Noise Frequency, Phillips Check, Energy Level Check)의 복합적인 사용(최적필터; Optimal Filter), 2) OOI(Ocean Observatories Initiative)에서 개발한 Spike Test 알고리즘(Spike Test) 그리고 3) 유의파고-주기 관계식을 이용한 새로운 필터(H-Ts QC)를 사용하여 신뢰도가 낮은 이상자료(Noise; 시계열 자료 중 급격하게 자료가 발산하여 정상자료가 아닌 것으로 판단되는 자료)의 제거 및 보정을 수행하였다. 결과적으로 3가지의 품질관리기법을 적용한 MWR의 파랑관측자료는 유의파고에 대해서는 일정 부분 신뢰도를 가지지만 유의파주기에서는 여전히 오차가 존재하며 이에 대한 개선이 요구된다. 또한, MWR의 파랑관측자료는 3m 이상의 고파랑에서는 CWB와 다소 양상이 달라지는 한계가 발생하므로 이를 위한 장기간의 원격파랑관측 자료의 수집과 분석, 그리고 필터 개발 등에 관한 지속적인 연구가 필요하다. Wave observation is widely used to direct observation method for observing the water surface elevation using wave buoy or pressure gauge and remote-sensing wave observation method. The wave buoy and pressure gauge can produce high-quality wave data but have disadvantages of the high risk of damage and loss of the instrument, and high maintenance cost in the offshore area. On the other hand, remote observation method such as radar is easy to maintain by installing the equipment on the land, but the accuracy is somewhat lower than the direct observation method. This study investigates the data quality of MIROS Wave and Current Radar (MWR) installed at Dokdo and improve the data quality of remote wave observation data using the wave buoy (CWB) observation data operated by the Korea Meteorological Administration. We applied and developed the three types of wave data quality control; 1) the combined use (Optimal Filter) of the filter designed by MIROS (Reduce Noise Frequency, Phillips Check, Energy Level Check), 2) Spike Test Algorithm (Spike Test) developed by OOI (Ocean Observatories Initiative) and 3) a new filter (H-Ts QC) using the significant wave height-period relationship. As a result, the wave observation data of MWR using three quality control have some reliability about the significant wave height. On the other hand, there are still some errors in the significant wave period, so improvements are required. Also, since the wave observation data of MWR is different somewhat from the CWB data in high waves of over 3 m, further research such as collection and analysis of long-term remote wave observation data and filter development is necessary.

해상관측부이의 현장 안정성 및 성능 예측을 위한 수치해석 : 정적해석

전인식(Insik Chun),민용침(Yongchim Min),민인기(In-Ki Min) 한국연안방재학회 2020 한국연안방재학회지 Vol.7 No.4

It is very important to predict the in-situ stability and performance of ocean surface buoys prior to the their installations in order to prevent their damages and to achieve high quality observation data. In the present study, a numerical method was set up to predict the static behaviors of the single point moored observation buoys subject to stationary loads by wind and/or currents. The numerical analysis was applied to the condition of an existing hydraulic experiment, and it appeared that both numerical and experimental results agreed well within an appropriate range of the drag coefficient of buoy. In addition, through the numerical analysis, the possibility of total submersion of buoy at very high current velocities was demonstrated together with a suggestion of its counter-action.

천해역 경사 천퇴에 설치된 해양구조물의 층하고 검토를 위한 수치해석 - 가거초 종합해양과학기지의 태풍피해 (2011)

김선신(Sun-Sin Kim),민용침(Yong-Chim Min),전인식(In-Sik Chun),심재설(Jae-Seol Shim) 한국연안방재학회 2017 한국연안방재학회지 Vol.4 No.3

The design wave and deck clearance of an offshore structure are very important factors to secure the stability of the structure after construction. In case that the structure is installed on a deep flat bottom, the deck clearance may be determined from the maximal wave crest height which can be sought by directly applying a nonlinear wave theory (Cnoidal or Stream function theory) to the design wave condition. But it is often the case that the structure is placed on a shallow underwater shoal having a steep slope due to construction expense and convenience. In this case, the wave height and depth conditions at the structural position may easily exceed the wave breaking condition beyond which the nonlinear wave theory cannot be applied. In the present study, a numerical method using a shallow water wave propagation model based on Boussinesq equation is demonstrated to reproduce the nonlinear wave deformation along up the shallow underwater shoal and the maximal wave crest height at the structural position. The method is applied to check the validity of the existing deck height of Gageocho Ocean Research Station installed on an underwater shoal in Korea. The station was damaged by typhoon Muifa in 2011 with the cellar deck and its appurtenance seriously deformed or destroyed.

이어도 종합해양과학기지의 비디오 이미지를 이용한 Whitecap coverage 관측 기법 수립

김선신(Sun-Sin Kim),민용침(Yong-chim Min),정종민(ong-min Jeong),민인기(In-Ki Min),정진용(Jin-Yong Jeong),심재설(Jae-Seol Shim) 한국연안방재학회 2016 한국연안방재학회지 Vol.3 No.4

Result from the global environmental changes represented by global warming, environmental variables including the sea temperature and sea surface height rise, ocean acidification, etc are reported to being in progress rapidly. Many studies have been carried out to understand the cause of the environmental changes and to deal with the impact. The environmental changes are closely related to the interaction between the ocean and atmosphere, especially in the boundary layer between them. So many studies on the energy and material, such as carbon dioxides, exchanges between the ocean and atmosphere are under going. In recent years, whitecap is recognized as the important parameters for the interaction between the ocean and atmosphere. There have been many efforts to observe and qualifying variables related to whitecap. Whitecap is the direct result from the wave breaking which have large temporal and spatial variability, and it is very hard to do quantitative observation. Previous studies have suggested the analytical solution, which defined the whitecap coverage, calculated from the wind, as a primary variable. Recently, owing to development in the image processing technologies, videos and still images are being used to observe whitecap coverage. But it has been very hard to obtain the continuous, precise wave images in the ocean. In this study, wave image obtained in the Ieodo Ocean Research Station were used to reduce the error of the conversion from image to whitecap coverage, and the formula which suggested by Sugihara et al. (2007). Specifically, it presented Pixel intensity threshold determination method and criteria image sampling frequency of Whitecap.

고무막체 파라펫 및 동적구조물 개발

전인식(Insik Chun),김선신(Sunsin Kim),민용침(Yongchim Min) 한국해양환경·에너지학회 2012 한국해양환경공학회 학술대회논문집 Vol.2012 No.5