• The Korean Journal of Ecology
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• 제7권3호
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• pp.109-118
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• 1983

Near future dynamics of water qualities (nutrient concentration) of the Han River was predicted, based on a mathematical model representing the relationship between the nutrient concentration in th river wagter and environmental factors (population density, land-use types, rock compositions and nutrient accumulation) in the basin. The population density and land-use types were forecasted to change distinctly in the downstream area, especially in Seoul City area in 1985~1990 whereas any environmental factor was not expected to change its level significantly in both upstream and middle reaches areas. It was indicated by the model that the nutrients concentration in the up- and mid-streams would keep its level in future as it was, but it would increase drastially in the downstream area. For the preservation of the water qualities in the downstream at least to keep its level as it was in 1980, practical countermeasures were proposed, based on the assessment of the contribution of each environmental factor to the water qualities.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.707-711
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• 2004

We analyze the information level of local small and medium business in the base of Nolan's growth stage model. To estimate information level we do separate level analysis for six sections and integrated total level analysis. After analyzing information level of business, we focus on the factors of this result to understand the most influential environments. The local business we were studying are the third stage-control stage. But Organization of information department and Planning and control of information are the second stage. The number of computer system application field is very related to information level. We present the critical factors of information level of small and medium business.

• 한국농공학회논문집
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• 제49권4호
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• pp.13-22
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• 2007

The uncertainty in water quality model predictions is inevitably high due to natural stochasticity, model uncertainty, and parameter uncertainty. An integrated modeling system under uncertainty was described and demonstrated for use in watershed management and receiving-water quality prediction. A watershed model (HSPF), a receiving water quality model (WASP), and a wetland model (NPS-WET) were incorporated into an integrated modeling system (modified-BASINS) and applied to the Hwaseong Reservoir watershed. Reservoir water quality was predicted using the calibrated integrated modeling system, and the deterministic integrated modeling output was useful for estimating mean water quality given future watershed conditions and assessing the spatial distribution of pollutant loads. A Monte Carlo simulation was used to investigate the effect of various uncertainties on output prediction. Without pollution control measures in the watershed, the concentrations of total nitrogen (T-N) and total phosphorous (T-P) in the Hwaseong Reservoir, considering uncertainty, would be less than about 4.8 and 0.26 mg 4.8 and 0.26 mg $L^{-1}$, respectively, with 95% confidence. The effects of two watershed management practices, a wastewater treatment plant (WWTP) and a constructed wetland (WETLAND), were evaluated. The combined scenario (WWTP + WETLAND) was the most effective at improving reservoir water quality, bringing concentrations of T-N and T-P in the Hwaseong Reservoir to less than 3.54 and 0.15 mg ${L^{-1}$, 26.7 and 42.9% improvements, respectively, with 95% confidence. Overall, the Monte Carlo simulation in the integrated modeling system was practical for estimating uncertainty and reliable in water quality prediction. The approach described here may allow decisions to be made based on probability and level of risk, and its application is recommended.

• 한국시뮬레이션학회논문지
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• 제24권1호
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• pp.9-16
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• 2015

본 논문에서는 표준연동 아키텍처(HLA/RTI)기반 다해상도 연동이 가능한 시뮬레이션을 구성하여 공학급(QUEST), 교전급(SADM), 임무급(EADSIM)의 모델을 연동하였다. 공학급 모델은 전투실험 공학분석 시범체계에서 개발된 전투실험 통합개발환경(QUEST)을 이용하여 모델을 개발하였다. 교전급 모델은 SADM을 이용하여 개발하고 임무급 모델은 EADSIM을 이용하여 모델을 개발하였다. 여러 계층의 모델을 연동하기 위해 표준 연동 아키텍처 기반(HLA/RTI)으로 설계하고 구현하였다. 각기 다른 분산된 환경에서 수행되고 있는 시뮬레이션 프로그램들이 상호 연동을 위해 표준 연동 인터페이스 명세에 만족하는 연동 시뮬레이션을 설계하고 각 시뮬레이션 프로그램 간의 중계 역할을 담당하는 통합연동 게이트웨이를 개발하였다. 다해상도 연동 시뮬레이션을 통해 여러 계층 간의 모델을 연동하여 해양 무기체계 효과도 분석을 위한 모델충실도를 향상하고 운용자 필요에 따라 요구되는 전장 환경을 신속하게 구성할 수 있다. 또한 표준연동 아키텍처(HLA/RTI)를 기반으로 설계하게 된 다른 시뮬레이션 프로그램과도 쉽고 효율적으로 연동할 수 있다.

• 한국환경과학회지
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• 제22권5호
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• pp.515-522
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• 2013

To investigate groundwater variation characteristics in the Hancheon watershed, Jeju Island, an integrated hydrologic component analysis was carried out. For this purpose, SWAT-MODFLOW which is an integrated surface-groundwater model was applied to the watershed for continuous watershed hydrologic analysis as well as groundwater modeling. First, ephemeral stream characteristics of Hancheon watershed can be clearly simulated which is unlikely to be shown by a general watershed hydrologic model. Second, the temporally varied groundwater recharge can be properly obtained from SWAT and then spatially distributed groundwater recharge can be made by MODFLOW. Finally, the groundwater level variation was simulated with distributed groundwater pumping data. Since accurate recharge as well as abstraction can be reflected into the groundwater modeling, more realistic hydrologic component analysis and groundwater modeling could be possible.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.287-287
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• 2023

Surface water-groundwater interaction (SWGI) is an important hydrological process that influences both the quantity and quality of water resources. However, regional scale SWGI model calibration and uncertainty analysis have been a challenge because integrated models inherently carry a vast number of parameters, modeling assumptions, and inputs, potentially leaving little time and budget to explore questions related to model performance and forecasting. In this study, we have proposed the application of iterative ensemble smoother (IES) for uncertainty analysis and calibration of the widely used integrated surface-subsurface model, SWAT-MODFLOW. SWAT-MODFLOW integrates Soil and Water Assessment Tool (SWAT) and a three-dimensional finite difference model (MODFLOW). The model was calibrated using a parameter estimation tool (PEST). The major advantage of the employed IES is that the number of model runs required for the calibration of an ensemble is independent of the number of adjustable parameters. The pilot point approach was followed to calibrate the aquifer parameters, namely hydraulic conductivity, specific storage, and specific yield. The parameter estimation process for the SWAT model focused primarily on surface-related parameters. The uncertainties both in the streamflow and groundwater level were assessed. The work presented provides valuable insights for future endeavors in coupled surface-subsurface modeling, data collection, model development, and informed decision-making.

• 한국정보처리학회논문지
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• 제4권9호
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• pp.2354-2365
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• 1997

본 논문은 현대의 정보 통신 응용에서 접근제어 요구 사항의 복잡한 문제를 해결하기 위한 접근제어 매커니즘의 설계 방안을 제시한다. 본 논문에서는 자원의 기밀성, 무결성 및 가용성의 공통적 목적을 달성하기 위한 통합 정보 모델을 제안 하고, 신분-기반, 규칙-기반 및 직무-기반의 관점에서 각 관련된 정책과 규칙을 정의하였으며, 필요한 접근제어 오퍼레이션들을 구현하였다. 제안된 통합 정보 모델은 보안 레이블, 무결성 등급, 직무 및 소유권 등의 다단계 보안 정책을 기반으로 하여 자원에 대한 불법적인 접근을 방어할 수 있다.

• 한국BIM학회 논문집
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• 제1권2호
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• pp.12-18
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• 2011

건설 프로젝트 생애주기 전반에 걸쳐 생성되는 정보를 3차원 모델을 기반으로 관리하는 BIM (Building Information Modeling) 기술은 계획, 설계, 구조해석은 물론 견적 및 3차원 시뮬레이션을 통한 시공계획 등 공사관리 업무를 통합하는 방향으로 발전하고 있다. BIM 기반 견적모델은 3차원 모델의 사용 용도에 따라 상세수준의 차이와 모델정보의 차이를 보이는데, 본 연구에서는 교량 구조물을 대상으로 하여 견적을 위한 모델의 LOD 수준을 파악하였다. 또한 건설정보 분류체계에 적용되는 라이브러리의 클래스를 정의하고 Microstation의 API를 이용하여 클래스의 파라메터를 추출하여 파라메터와 연동되는 Resource의 물량정보를 산출한다. 견적 모델과 상이하게 모델링된 모델에서 하위 모델을 계층화 하고 견적수준으로 병합함으로써 BIM 기반 토목 라이브러리를 통한 견적자동화시스템을 검증하였다.

• 대한조선학회논문집
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• 제55권3호
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• pp.222-235
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• 2018

The hydrocarbon gas leak in the offshore plant can cause large accidents and lead to significant damages to human, property and environment. For prevention of fire or explosion accidents from gas leak, a SIS(Safety Instrumented System) should be installed. In the early stage of the offshore design, required SIL(Safety Integrated Level) is determined and reliability analysis is performed to verify the design in reliability aspects. This study collected data, information related to reliability analysis and created knowledge model of safety design for the offshore system with MBSE(Model-Based Systems Engineering) concept. Knowledge model could support safety engineer's design tasks as the guidance of reliability analysis procedure of safety design and make good conversation with other engineers in yard, class, company, etc.

• 대한산업공학회지
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• 제42권2호
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• pp.151-164
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• 2016

In this paper, we deal with a risk analysis for an IPS (Integrated power system) and propose a simulation model combining the fault tree and event tree in order to estimate the system availability and risk level, together. Firstly, the basic information such as operational scenarios, physical structure, safety systems is explained in order to make the fault tree and event tree of the IPS. Next, we propose a discrete-event simulation model using a next-event time advance technique to advance the simulation time. Also the state transition and activity diagrams are explained to represent the relationship between the objects. By numerical examples, the redundancy allocation is considered in order to decrease the risk level of the IPS.