디바이스 설치환경에 따른 공용전원의 최적 분할방안

서광호,이동형 한국산업경영시스템학회 2021 한국산업경영시스템학회 학술대회 Vol.2021 No.춘계

대청호 오수관로 배수펌프 고장 최소화를 위한 펌프가동 방법 제안

서광호,이동형,김기태 한국산업경영시스템학회 2023 한국산업경영시스템학회 학술대회 Vol.2023 No.추계

차수판의 수직하중에 의한 변형 성능 시험방법

서광호,김기태 한국산업경영시스템학회 2023 한국산업경영시스템학회 학술대회 Vol.2023 No.춘계

Evaluation of a Regional Ocean Reanalysis System for the East Asian Marginal Seas based on the Ensemble Kalman Filter

서광호,최병주,조양기,김영호,김상일 한국해양과학기술원 2015 Ocean science journal Vol.50 No.1

This study introduces the East Asian Marginal Seas (EAMS) reanalysis system and evaluates its products from 1982 to 2006. The EAMS reanalysis system consists of an ocean circulation model with 0.25° horizontal grid spacing and a data assimilation module. Temperature profiles taken by ship and Argo floats as well as satellite-borne sea surface temperature (SST) were assimilated into the model by applying the ensemble Kalman filter every 7 days. The reanalyzed oceanic fields were compared with ones by the control run without data assimilation to assess the impact of the data assimilation. The assimilative model significantly improved the horizontal structures of SST, sea surface height (SSH), vertical structure of temperature, and volume transports through the major straits. Root-mean-square error (RMSE) of SST decreased from 1.0 to 0.6°C. Horizontal and vertical distribution of subsurface temperature was corrected close to the observed values. High SSH variability in the south of Japan and in the Kuroshio extension region was partially restored. Overshooting of the Kuroshio Current and the East Korea Warm Current was suppressed to the south by the data assimilation. SSH and surface circulation in the Oyashio region and in the East Sea (also known as the Sea of Japan) recovered, which corrected the sea level difference between the East Sea and the Pacific Ocean and produced realistic transport through the Korea Strait. The reanalysis well resolved transport through the Korea Strait. The correlation coefficient with the transport based on an Acoustic Doppler Current Profiler measurement was 0.70 and the RMSE was 0.37 Sv (106 m3/s), whereas those were 0.59 and 0.43 Sv in the control run, respectively. The EAMS reanalysis dataset may help us to understand circulation variations in the marginal seas and to investigate factors controlling volume and heat transport.

Assimilation of Sea Surface Temperature in the Northwest Pacific Ocean and its Marginal Seas using the Ensemble Kalman Filter

서광호,최병주,조양기,김영호,김상일 한국해양과학기술원 2010 Ocean science journal Vol.45 No.4

Satellite-borne sea surface temperature (SST) data were assimilated with the ensemble Kalman filter (EnKF) in a Northwest Pacific Ocean circulation model to examine the effect of data assimilation. The model domain included the northwestern part of the Pacific Ocean and its marginal seas, such as the Yellow Sea and East/Japan Sea. The performance of the data assimilation was evaluated by comparing the simulated ocean state with that observed. Spatially averaged root-meansquared errors in the SST and sea surface height (SSH) decreased by 0.44 °C and 4 cm, respectively, by the assimilation. The results of the numerical experiments substantiated the effectiveness of the SST assimilation via the EnKF for all marginal seas, as well as the Kuroshio region. The benefit of the data assimilation depended on the characteristics of each marginal sea. The variation of the SST in the East/Japan Sea and the Kuroshio extension (KE) region were improved 34% and those in the Yellow Sea 12.5%. The variation of the SSH was improved approximately 36% in the KE region. This large improvement was achieved in the deep-water regions because assimilation of SST data corrected the separation point of the western boundary currents, such as the Kuroshio and the East Korea Warm Current, and the associated horizontal surface currents. The SST assimilation via the EnKF also improved the subsurface temperature profiles. The effectiveness of SST assimilation was seasonally dependent, with the improvement being relatively larger in winter than in summer, which was related to the seasonal variation of the vertical mixing and stratification in the ocean surface layer.

초등학생의 학교스포츠클럽 참여와 인성특성과의 관계

서광호,정구인 한국교원대학교 학교체육연구소 2009 학교체육연구소지 Vol.16 No.1

The purpose of study proffer the proper teaching method of sports club and the orientation and the based data for the education of the trait hunanity and the school sports club programs in elementary students, as searching the relations of the participati

기후변화 시나리오 기반 연안재해 위험평가 방안 연구

서광호,오현주,정광영,이화영,김수민,김명원,강태순 한국기후변화학회 2023 한국기후변화학회지 Vol.14 No.6

Korea's coastal areas are experiencing amplified natural disasters due to the acceleration of climate change, resulting in loss of life and property damage. There is a growing demand for scientific disaster information to prepare for increased coastal inundation and erosion due to sea level rise and typhoon intensity under climate change. However, current coastal disaster assessments rely primarily on past climate data. In this study, we established a coastal disaster risk assessment system that considers future climate change conditions. The Korea Meteorological Administration's climate change scenario SSP (Shared Socioeconomic Pathways) 5-8.5 was selected based on data resolution, applicability, and ease of data collection. The study area was designated as the coast of Busan, South Korea, and a grid system with a 100-m interval was established in the coastal inland area, as stipulated by the Coast Management Act. Basic data for exposure and vulnerability indexes were obtained from authorized organizations such as the National Institute of Fisheries Science and the National Geographic Information Institute. Output data from the East Asia (25 km) climate change scenario was utilized as input for the numerical model to calculate the wave and tsunami components of the hazard index. For wind and rainfall, we used output data from the Korea Meteorological Administration's Korea (1 km) climate change scenario. For sea level rise, we used data from the National Institute of Fisheries Science's future projection of climate change response. The assessment applied formulas based on the IPCC AR5 assessment framework to calculate the results for each scenario. The results of this study are expected to provide information on coastal hazards considering future climate change and to help establish coastal hazard reduction measures.

DC공용전원 사용환경에서 연동형 온도수집장치의 전압강하 공식 도출

서광호,이동형 국제차세대융합기술학회 2022 차세대융합기술학회논문지 Vol.6 No.5

한전 전력구내에 설치된 온도감시시스템은 원가절감, 효율적인 전력제어 및 시공의 편의성을 위해 하나의 DC 공용전원을 사용하여 여러 기기에 전원을 공급하는 데이지체인(Daisy chain) 방식을 사용하고 있다. 그러나 온도감시시스템에서의 적정한 전선거리 및 온도수집장치 수량을 알 수가 없어 전선거리가 기준을 넘어서거나 온 도수집장치가 적정량보다 많아지면 시공 후 전원 끊김 등 오작동 문제가 발생한다. 이에 본 연구에서는 공용전원 을 사용할 때 스위칭 레귤레이터가 적용된 연동형 온도수집장치의 거리에 따른 종단전압 예측 및 도출 공식을 제 시하고자 한다. 본 연구결과는 온도감시스템 설계시 적정 거리 및 기기 수량 산정을 통해 과잉설계 및 설계오류를 예방하고 신속한 사후고장 관리에 기여할 것으로 판단된다. The temperature monitoring system installed in KEPCO's power premises uses a daisy chain method that supplies power to several devices using one DC common power source for cost reduction, efficient power control, and convenience of construction. However, if the electric wire distance exceeds the standard or the temperature collection device exceeds the appropriate amount, malfunction problems such as power loss will occur after construction. Therefore, this study proposes a formula for predicting and deriving the end voltage according to the distance of the interlocking temperature collector to which the switching regulator is applied when using a shared power source. The results of this study are expected to prevent excessive design and design errors and contribute to rapid post-failure management by calculating the appropriate distance and device quantity when designing the temperature sensing system.

역학적 다운스케링일 기법을 이용한 한반도 주변해역 기후변화 수치모의

서광호,조양기,최병주,김봉국 한국연안방재학회 2013 한국연안방재학회 학술발표대회 논문집 Vol.2013 No.-

Long-term Comparison of Satellite and in-situ Sea Surface Temperatures around the Korean Peninsula

곽명택,서광호,조양기,김봉국,유승협,서장원 한국해양과학기술원 2015 Ocean science journal Vol.50 No.1

Satellite remotely sensed sea surface temperature (SST) was compared with in-situ SST in the seas around the Korean Peninsula from 1984 to 2013. A matchup dataset between satellite and in-situ SSTs was used. The root mean square error (RMSE) between satellite and in-situ SSTs was approximately 1°C in the offshore area and 2~3°C in the coastal area. The satellite SST exhibits a cold bias of 1°C or less in the offshore area and a warm bias of 1~3°C in the coastal area. The satellite SSTs generally agree with the in-situ data in the East/Japan Sea (EJS) better than in the South Sea and the Yellow Sea (YS). The RMSE between the two SSTs in the South Sea (SS) is 1~2°C. In-situ and satellite SST analyses respectively indicate a warming trend of 0.024°C/year and 0.011°C/year for the study period in the seas around the Korean Peninsula. The difference in the long-term trends from the two data sources is mainly due to the difference in the YS. The satellite SST showed a warm bias of 0.5~1.0°C in the early 1980’s and a cold bias of 0.5°C in the early 2010’s, which should be carefully considered in studying long-term trends with satellite SST data.