• Journal of Ecology and Environment
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• 제47권2호
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• pp.49-62
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• 2023

Background: Over the past three decades, gradual eustatic sea-level rise has been considered a primary exogenous factor in the increased frequency of flooding and biological changes in several salt marshes. Under this paradigm, the potential importance of short-term events, such as ocean storminess, in coastal hydrology and ecology is underrepresented in the literature. In this study, a simulation was developed to evaluate the influence of wind waves driven by atmospheric oscillations on sedimentary and vegetation dynamics at the Skallingen salt marsh in southwestern Denmark. The model was built based on long-term data of mean sea level, sediment accretion, and plant species composition collected at the Skallingen salt marsh from 1933-2006. In the model, the submergence frequency (number yr^-1) was estimated as a combined function of wind-driven high water level (HWL) events (> 80 cm Danish Ordnance Datum) affected by the North Atlantic Oscillation (NAO) and changes in surface elevation (cm yr^-1). Vegetation dynamics were represented as transitions between successional stages controlled by flooding effects. Two types of simulations were performed: (1) baseline modeling, which assumed no effect of wind-driven sea-level change, and (2) experimental modeling, which considered both normal tidal activity and wind-driven sea-level change. Results: Experimental modeling successfully represented the patterns of vegetation change observed in the field. It realistically simulated a retarded or retrogressive successional state dominated by early- to mid-successional species, despite a continuous increase in surface elevation at Skallingen. This situation is believed to be caused by an increase in extreme HWL events that cannot occur without meteorological ocean storms. In contrast, baseline modeling showed progressive succession towards the predominance of late-successional species, which was not the then-current state in the marsh. Conclusions: These findings support the hypothesis that variations in the NAO index toward its positive phase have increased storminess and wind tides on the North Sea surface (especially since the 1980s). This led to an increased frequency and duration of submergence and delayed ecological succession. Researchers should therefore employ a multitemporal perspective, recognizing the importance of short-term sea-level changes nested within long-term gradual trends.

• 한국환경보건학회지
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• 제49권6호
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• pp.334-343
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• 2023

Background: South Korea's Act on Registration and Evaluation, etc. of Chemicals (known as K-REACH) was established to protect public health and the environment from hazardous chemicals. 4,4'-Methylenedianiline (MDA), which is used as a major intermediate in industrial polymer production and as a vulcanizing agent in South Korea, is classified as a toxic substance under the K-REACH act. Although MDA poses potential ecological risks due to industrial emissions and hazards to aquatic ecosystems, no ecological risk assessment has been conducted. Objectives: The aim of this study is to assess the ecological risk of MDA by identifying the actual exposure status based on the K-REACH act. Methods: Various toxicity data were collected to establish predicted no effect concentrations (PNECs) for water, sediment, and soil. Using the SimpleBox Korea v2.0 model with domestic release statistical data and EU emission factors, predicted environmental concentrations (PECs) were derived for ten sites, each referring to an MDA-using company. Hazard quotient (HQ) was calculated by ratio of the PECs and PNECs to characterize the ecological risk posed by MDA. To validate the results of modeling-based assessment, concentration of MDA was measured using in-site freshwater samples (two to three samples per site). Results: PNECs for water, sediment, and soil were 0.000525 mg/L, 4.36 mg/kg dw, and 0.1 mg/kg dw, respectively. HQ for surface water and sediment at several company sites exceeded 1 due to modeling data showing markedly high PEC in each environmental compartment. However, in the results of validation using in-site surface water samples, MDA was not detected. Conclusions: Through an ecological risk assessment conducted in accordance with the K-REACH act, the risk level of MDA emitted into the environmental compartments in South Korea was found to be low.

• 환경영향평가
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• 제21권3호
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• pp.461-468
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• 2012

In general, long-term changes of ecological factors take a pulse form in which they interact with other factors and go through a repeated increasing and decreasing cycle. The coupling of the two approaches the grid model and the box model in ecological modeling can lead to an in-depth understanding of the environment. The study analyzes temporal variations of major storages with an energy system model that formulizes effectively the relationships among nutrients, phytoplankton, and zooplankton in the Yellow Sea and the East China Sea. An increase of light intensity and standing stock of nutrient increase the magnitude and frequency of pulsing. Also, an immense reduction of nutrient concentration can cause extinction of the pulsing and bring about a steady state. It is concluded that the nutrient loads in freshwater discharge from the Yangtze affect the cycles of major ecological components as well as water quality variables and play an important role in the marine ecosystem.

• 한국습지학회지
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• 제1권1호
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• pp.51-59
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• 1999

As important ecological systems, wetlands contribute a wide array of biological, social. and economic benefits. However, wetlands are lost until the present, primarily due to human induced land-use conversions. Society is placing demands for the efficient preservation and management on Woopo wetland as the first largest wetland in Korea. GIS(Geographic Information System) is a rapidly developing technology for handling, analyzing, and modeling ecological information on wetlands. In the paper, Woopo Wetland Management System has been developed by using Desktop GIS and Internet GIS technology to embrace major functions: information query and browsing, spatial searching on map, and rule-based analysis. As a menu-driven system, these functions are designed to be implemented through customized menus. The developed system is expected to be used for the effective publicity service as well as the professional management of Woopo.

• KIEAE Journal
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• 제15권5호
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• pp.95-105
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• 2015

Purpose: This paper presents a framework development for BIM (Building Information Modeling)-based OOPM (Object-Oriented Physical Modeling) for Building Thermal Simulation. The framework facilitates decision-making in the design process by integrating two object-oriented modeling approaches (BIM and OOPM) and efficiently providing object-based thermal simulation results into the BIM environment. Method: The framework consists of a system interface between BIM and OOPM-based building energy modeling (BEM) and the visualization of simulation results for building designers. The interface enables a BIM models to be translated into OOPM-based BEM automatically and the thermal simulation from the created BEM model immediately. The visualization module enables the simulation results to be presented in BIM for building designers to comprehend the relationships between design decisions and the building performances. For the framework implementation, we utilized the Modelica Buildings Library developed by the Lawrence Berkeley National Laboratory as a thermal simulation solver. We also conducted an experiment to validate the framework simulation results and demonstrate our framework. Result: This paper demonstrates a new methodology to integrate BIM and OOPM-based BEM for building thermal simulation, which enables an automatic translation BIM into OOPM-based BEM with high efficiency and accuracy.

• 한국농림기상학회지
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• 제15권4호
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• pp.219-233
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• 2013

본 연구는 산림에서 나타나는 수종의 분포 패턴을 해석하고 예측하기 위한 목적으로 수행되었다. 국내에서 처음으로 시도된 전국 규모의 체계적 산림조사라 할 수 있는 NFI (National Forest Inventory)의 수종별 출현 정보와 출현지점별 풍부도를 기반으로 소나무의 현존분포도를 작성하였다. 생태적 지위 모형의 하나인 GARP (Genetic Algorithm for Ruleset Production)를 이용하여 소나무 현존분포와 연관성이 높은 환경요인변수들을 선정하였고, 선정된 변수들을 설명변수로 하는 소나무 잠재분포 모형을 작성한 후 기후변화 시나리오를 적용하여 미래의 잠재분포를 예측하였다. 기후, 지리 지형, 토양 지질, 토지이용 및 식생현황 등 27개 환경요인변수를 각각 설명변수로 하여 모형을 구동함으로써 소나무 현존분포와의 연관성을 평가한 결과 1월 평균기온이 최상위를 차지하였고 연평균기온, 8월평균기온, 연교차 등도 영향을 미치는 것으로 분석되었다. NFI 정보로부터 추출하여 소스개체군으로 선정된 조사지점들을 소나무의 최종출현정보로, 환경요인변수 간의 연관성 분석을 통해 최종적으로 선정된 변수 세트를 설명변수로 하여 모형을 구동함으로써 최적의 모형을 선정한 후 잠재분포도를 작성하였다. 현재 시점의 환경요인변수들에 의해 트레이닝 된 잠재분포 모형에서 기후관련변수들을 RCP 8.5 기후변화시나리오에서 산출한 변수들로 대체하여 2020년대, 2050년대, 2090년대의 소나무의 예측 잠재분포도를 작성하였다. 최종적으로 작성된 소나무 잠재분포모형의 평가 통계량인 AUC (Area Under Curve)는 0.67로 다소 미흡하였으나 향후 기후변화 환경 하에서 소나무림의 보전 및 관리를 위한 최소한의 실마리를 제공할 수 있을 것으로 판단되었다.

• 한국환경과학회지
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• 제14권9호
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• pp.835-842
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• 2005

The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of COD (chemical oxygen demand) and net supply(or decomposition) rate of COD in Kamak Bay to find proper management plan for oxygen demanding organic matters. The estimation results of the physical process in terms of COD showed that transportation of COD is dominant in surface level while accumulation of COD is dominant in bottom level. In the case of surface level, the net supply rate of COD was 0 -0.50 mg/m2/day. The net decomposition rate of COD was 0 -0.04 mg/m2/day in middle level(3 -6m) and 0.05 -0.1 5 mg/m2/day in bottom level(6m -bottom). These results indicates that the biological decomposition and physical accumulation of COD are occurred predominantly at the northern part of bottom level. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters in the region.

• BMB Reports
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• 제45권8호
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• pp.476-481
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• 2012

Flavodoxin (Fld) has been demonstrated to bind to ferredoxin-NADP$^+$ reductase A (FprA) in Pseudomonas putida. Two residues ($Phe^{256}$, $Lys^{259}$) of FprA are likely to be important for interacting with Fld based on homology modeling. Site-directed mutagenesis and pH-dependent enzyme kinetics were performed to further examine the role of these residues. The catalytic efficiencies of FprA-$Ala^{259}$ and FprA-$Asp^{259}$ proteins were two-fold lower than those of the wild-type FprA. Homology modeling also strongly suggested that these two residues are important for electron transfer. Thermodynamic properties such as entropy, enthalpy, and heat capacity changes of FprA-$Ala^{259}$ and FprA-$Asp^{259}$ were examined by isothermal titration calorimetry. We demonstrated, for the first time, that $Phe^{256}$ and $Lys^{259}$ are critical residues for the interaction between FprA and Fld. Van der Waals interactions and hydrogen bonding were also more important than ionic interactions for forming the FprA-Fld complex.

• 한국환경과학회지
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• 제12권8호
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• pp.841-846
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• 2003

The ecosystem model was applied to estimate the regional distribution of the net production(or consumption) of phytoplankton and the net uptake(or regeneration) rate of nutrients in Masan Bay for scenario analysis to find a proper management plan. At the surface level, net production of phytoplankton is 200 mgC/㎡/day at the entrance of the bay, and 400∼1000 mgC/㎡/day at the center of the bay. The inner area of the bay showed more than 2000 mgC/㎡/day. All areas of the bottom level have a net consumption, with the center of the bottom level showing more than 600 mgC/㎡/day. For dissolved inorganic nitrogen, the results showed a net uptake rate of 100∼900 mg/㎡/day at the surface level. It showed that the net regeneration is above 50 mg/㎡/day at the bottom level. For dissolved inorganic phosphorus, the net uptake rate showed 10.0∼80.0 mg/㎡/day at the surface level, and the regeneration rate showed 0∼20.5 mg/㎡/day at the bottom level. Therefore, in order to control the water quality in Masan Bay, it is important to consider the re-supplement of nutrients regenerated in the water column.

• 대한산업공학회지
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• 제37권2호
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• pp.96-104
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• 2011

Modeling and simulation of human-involved complex systems pose challenges to representing human decision makings into logical systems because of the nondeterministic and dynamic nature of human behaviors. In modeling perspectives, human's activities in systems can increase uncertainty and complexity, because he or she can potentially access all other resources within the system and change the system states. To address all of these human involvements in the system, this research suggests applying the Finite State Automata (FSA)-based formal modeling of human-involved systems that incorporates the ecological concept of affordances to an evacuation simulation, so that human behavioral patterns under urgent and dynamic emergency situations can be considered in the real-time simulation. The proposed simulation methodologies were interpreted using the warehouse fire evacuation simulation to clarify the applicability of the proposed methodology. This research is expected to merge system engineering technologies and human factors, and come out to the new predictive modeling methodology for disaster simulations. This research can be applied to a variety of applications such as building layout designs and building access control systems for emergency situations.