기후정보와 지리정보를 결합한 계층적 베이지안 모델링을 이용한 재현기간별 일 강우량의 공간 분포 및 불확실성

이정훈,이옥정,서지유,김상단,Lee, Jeonghoon,Lee, Okjeong,Seo, Jiyu,Kim, Sangdan 한국수자원학회 2021 한국수자원학회논문집 Vol.54 No.10

Quantification of extreme rainfall is very important in establishing a flood protection plan, and a general measure of extreme rainfall is expressed as an T-year return level. In this study, a method was proposed for quantifying spatial distribution and uncertainty of daily rainfall depths with various return periods using a hierarchical Bayesian model combined with climate and geographical information, and was applied to the Seoul-Incheon-Gyeonggi region. The annual maximum daily rainfall depth of six automated synoptic observing system weather stations of the Korea Meteorological Administration in the study area was fitted to the generalized extreme value distribution. The applicability and reliability of the proposed method were investigated by comparing daily rainfall quantiles for various return levels derived from the at-site frequency analysis and the regional frequency analysis based on the index flood method. The uncertainty of the regional frequency analysis based on the index flood method was found to be the greatest at all stations and all return levels, and it was confirmed that the reliability of the regional frequency analysis based on the hierarchical Bayesian model was the highest. The proposed method can be used to generate the rainfall quantile maps for various return levels in the Seoul-Incheon-Gyeonggi region and other regions with similar spatial sizes.

Validations of a Numerical Model of Solute Transport in a Snowpack

이정훈,Lee, Jeonghoon The Korean Society of Economic and Environmental G 2012 자원환경지질 Vol.45 No.5

Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement.

활동기준원가계산법(Actvitiy-Based Costing)에 의한 모듈러 건축물 공장제작단계 간접비 산정 방안

이정훈,박문서,이현수,이광표,현호상,Lee, JeongHoon,Park, Moonseo,Lee, Hyun-Soo,Lee, Kwang-Pyo,Hyun, Hosang 한국건설관리학회 2015 한국건설관리학회 논문집 Vol.16 No.4

Modular construction is combined with manufacturing production process and conventional construction industry technique. Considering characteristic of modular construction production process, manufacturing facilities require indirect costs for utilities, equipment, and overall maintenance, which can affect modular units pricing. However, current modular construction cost classification is inadvertent to reflect the manufacturing overhead costs, because it is generally added as a percentage to sum of labor, material and equipment as it called in single cost pool used. This process is easy to estimate the total construction cost at the project starting points, but it brings on misunderstanding of project profit estimations by "cross subsidization phenomenon". To prevent this situation, in this research aims to provide modular construction overhead cost handling process at the detailed indirect cost calculation for manufacturing stage using Activity-Based Costing as one of the powerful method for overhead costs estimation and allocation. Using this research results, modular construction cost estimators have more detailed cost information of modular units and prevent to misallocate indirect costs. Also, it can be utilized to aid the understanding of the company's profit structure.

공통현 기반 삼변측량 보정 알고리즘 및 복합 측위 시스템 개발

이정훈,박부곤,김용길,최지훈,김정태,배경훈,Lee, Jeonghoon,Park, Bu-Gon,Kim, Yong-Kil,Choi, Ji-Hoon,Kim, Jung-Tae,Bae, Kyung-Hoon 한국정보통신학회 2020 한국정보통신학회논문지 Vol.24 No.3

Indoor positioning based on trilateration using common chord estimates location of a mobile subject by using intersection points between each circles which the radius is same as distance between the mobile subject and each radio-frequency transmitter. However, if the intersection points are not found due to error of the distance measurement, it causes failure of estimating the mobile subject's location. To prevent this case, numbers which is proportionate to radius of each circles, are temporarily added to each distances in order to lengthen radius of the circles. Although the estimated location includes error due to the radius extension, it is corrected again by the added value and distance from reference point. With introduction of the advanced correction algorithm, potential issues of existing trilateration such as failure of estimating location and distance measurement error will be minimized.

비점오염원 저감 LID 시설의 최적설치위치 결정 및 효율 정량화을 위한 분포형 수문모형의 개발

이정훈,조선주,김진관,서성철,김상단,Lee,Jeonghoon,Cho,Seon Ju,Kim,Jin Kwan,Seo,Seongcheol,Kim,Sangdan 한국방재학회 2012 한국방재학회논문집 Vol.12 No.4

본 연구에서는 도시 배수분구에서 배출되는 비점오염원을 저감하기 위하여 설치되는 저영향기법 시설들의 최적설치위치 결정 및 이러한 시설들의 효율을 정량화하기 위해 적용될 수 있는 분포형 수문모형이 제안된다. 제안된 모형은 정방형 셀을 기반으로 도시 배수분구의 강우유출수와 비점오염원의 유출을 모형화한다. 각각의 셀에서의 강우사상은 NRCS-CN 기법에 의하여 지표면 유출사상으로 전환되며, 비점오염원은 건기 시에 지표면에 축적되어 강우 시에 쓸림 과정을 통하여 배출된다. 모형은 지표면 유출수가 발생되어 하류 셀로 이동할 때 배수분구의 흐름경로를 명확하게 구현할 수 있기 때문에, LID 시설의 비점오염원 저감 효과뿐만 아니라 시설의 설치위치에 따른 효과를 정량적으로 살펴보는 것을 가능하게 한다. In this paper a simple distributed hydrologic model is proposed to determine optimal installation location of LID devices and to quantify their non-point sources reduction efficiency in urban drainage catchment. The proposed model is applied to simulate surface runoff and non-point sources loading on urban drainage based on square cells. In the model, rainfall events occurring at each cell are transformed into surface runoff events by NRCS-CN technique, and non-point sources pollutants which have been built-up at dry period are discharged at wet period by washed-off process. Since the model can represent the drainage flow path explicitly when the overland flow is occurred and moved into the next lower cell, it is possible to look at the effects of the LID facilities positioning as well as the non-point sources reducing efficiency of such facilities.

수증기안정동위원소를 이용한 해안지역 수분의 이동경로에 관한 연구

이정훈,최희진,오진만,나운성,곽호제,허순도,Lee, Jeonghoon,Choi, Heejin,Oh, Jinman,Na, Un-Sung,Kwak, Hoje,Hur, Soon Do 대한자원환경지질학회 2013 자원환경지질 Vol.46 No.4

Water vapor isotopes can be excellent tools for understanding complex mechanisms in the water cycle and atmospheric hydrological cycle and they can be applied to various fields of paleoclimatology, atmospheric science, hydrogeology, oceanography, and ecohydrology. Thus, studies of global or local transport of water vapor may be able to provide a very useful clue to better understand the movements of water and energy in the atmosphere, hydrosphere and biosphere. In this study, the isotopic compositions of water vapor have been observed for moisture transport during the passage of Typhoon Bolaven at Korea Polar Research Institute (KOPRI), Incheon, in the western part of Korea, from August 27 to August 29, 2012. In the clear sky, the isotopic compositions of water vapor at KOPRI exhibited relatively higher isotopic ratios, which were near isotopic equilibrium with sea surface water (${\delta}^{18}O$=-14‰). On the other hand, a largely depleted isotopic ratios in surface water vapor were observed in association with the passage of Typhoon Bolaven (approximately 10‰ depleted compared to the clear sky). The fact that the isotopic minima in water vapor are encountered during the onset period of the Typhoon Bolaven with increases of relative humidity, which is consistent with, so called, "the amount effect".

수증기안정동위원소의 물순환 해석에의 적용에 대한 고찰

이정훈,한영철,고동찬,김송이,나운성,Lee, Jeonghoon,Han, Yeongcheol,Koh, Dong-Chan,Kim, Songyi,Na, Un-Sung 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.3

Studies using stable water vapor isotopes have been recently conducted over the past two decades because of difficulties in analysis and sample collection in the past. Stable water vapor isotope data provide information of the moisture transport from ocean to continent, which are also used to validate an isotope enabled general circulation model for paleoclimate reconstructions. The isotopic compositions of groundwater and water vapor also provide a clue to how moisture moves from soil to atmosphere by evapotranspiration. International Atomic Energy Agency designates the stations over the world to observe the water vapor isotopes. To analyze the water vapor isotopes, a cryogenic sampling method has been used over the past two decades. Recently, two types of laser-based spectroscopy have been developed and remotely sensed data from satellites have the global coverage. In this review, measurements of isotopic compositions of water vapor will be introduced and some studies using the water vapor isotopes will also be introduced. Finally, we will suggest the future study in Korea.

눈 속에서의 용질이동 및 융설의 동위원소변동에 관한 모델개발

이정훈,Lee, Jeonghoon 한국지하수토양환경학회 2012 지하수토양환경 Vol.17 No.5

Chemical and isotopic variations of snowmelt provide important clues for understanding snowmelt processes and the timing and contribution of snowmelt to catchment or watershed in spring. The newly developed model includes a hydraulic exchange between mobile and immobile water (${\omega}$), and isotopic exchanges between both mobile water and ice ($f_1$) and immobile water and ice ($f_2$). Since the new model is based on the mobile-immobile water conceptualization, which is widely used for describing chemical tracer transport in snow, it allows simultaneous calculations of chemical as well as isotopic variations in snowpack discharge. We compare the model results with a study of solute transport and isotopic evolution of snowmelt in snow, using artificial rain-on-snow experiments with conservative anion ($Br^-$). These observations are used to test the newly developed model and to better understand physical processes in a seasonal snowpack where our model simulates the chemical and isotopic variations.

고해상도 강우동위원소변동에 대한 연구

이정훈,김송이,한영철,나운성,오윤석,김영희,김혜린,함지영,최혜빈,고동찬,Lee, Jeonghoon,Kim, Songyi,Han, Yeongcheol,Na, Un-Sung,Oh, Yoon Seok,Kim, Young-Hee,Kim, Hyerin,Ham, Ji-Young,Choi, Hye-Bin,Koh, Dong-Chan 대한자원환경지질학회 2015 자원환경지질 Vol.48 No.5

Isotopic compositions of precipitation have been used to understand moisture transport in the atmosphere and interactions between precipitation and groundwater. Isotopic compositions of speleothems and ice cores, so called, ''paleoarchives'', can be utilized to interpret climate of the past and global circulation models (GCMs). The GCMs are able to explain the paleoarchives, can be validated by the precipitation isotopes. The developments of stable isotope analyzers make high-resolution isotopic studies feasible. Therefore, a high-resolution study of precipitation isotopes is needed. For this study, precipitation samples were collected for every 5 to 15 minutes, depending on precipitation rates, using an auto-sampler for precipitation isotopes near coastal area. The isotopic compositions of precipitation range from -5.7‰ (-40.1‰) to -10.8‰ (-74.3‰) for oxygen (hydrogen). The slope of ${\delta}^{18}O-{\delta}D$ diagram for the whole period is 6.8, but that of each storm is 5.1, 4.2, 7.9 and 7.7, respectively. It indicates that evaporation occurred during the first two storms, while the latter two storm did not experience any evaporation. The isotopic fractionations of precipitation has significant implications for the water cycle and high-resolution data of precipitation isotopes will be needed for the future studies.

평형 냉동에 의한 물동위원소의 레일리분별

이정훈,정혜정,니암게렐 얄랄트,Lee, Jeonghoon,Jung, Hyejung,Nyamgerel, Yalalt 대한자원환경지질학회 2021 자원환경지질 Vol.54 No.1

Isotopic compositions of snow or ice have been used to reconstruct paleoclimate and to calculate contribution to streamwater using isotopic hydrograph separation as an end member. During freezing and melting of snow or ice, isotopic fractionation occurs between snow or ice and liquid water. Isotopic evolution during melting process has been studied by field, melting experiments and modeling works, but that during freezing has not been well studied. In this review, isotopic fractionation during equilibrium freezing is discussed using the linear relationship between two stable water isotopes (oxygen and hydrogen) and the Rayleigh fractionation. Snow, evaporated from nearby ocean and condensated, follows the Global Meteoric Water Line (slope of 8), but the melting and freezing of snow affect the linear relationship (slope of 19.5/3.1~6.3). The isotopic evolution of liquid water by freezing observed in the open system during Rayleigh fractionation is also seen in the closed system. The isotopic evolution of snow or ice in the open system where the snow or ice is continuously removed becomes more enriched than the residual liquid water by the fractionation factor. The isotopic evolution of snow or ice in the closed system eventually equals the original isotopic compositions of liquid water. It is expected the understanding of isotopic evolution of snow or ice by freezing to increase the accuracy of the paleoclimate studies and hydrograph separation.