• Journal of Ocean Engineering and Technology
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• v.20 no.1 s.68
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• pp.55-62
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• 2006

Recently, pollution by development in coastal areas is going from bad to worse. The Korean government is attempting to make policies that prevent water pollution, but it is still difficult to say whether such measures are lowering pollution to an acceptable level. More specifically, the general investigation that has been done in KOREA does not accurately reflect the actual conditions of pollution in coastal areas. An investigation that quantitatively assesses water quality management using rational prediction technology must be attempted, and the ecosystem model, which incorporates both the 3-dimensional hydrodynamic and material cycle models, is the only one with a broad enough scope to obtain accurate results. The hydrodynamic model, which includes advection and diffusion, accounts for the ever-changing flow and (quality) of water in coastal areas, while the material cycle model accounts for pollutants and components of decomposition as sources of the carbon, phosphorus, and nitrogen cycles. In this paper, we simulated the rates of dissolved oxygen (DO), chemical oxygen demand (COD), total nitrogen(T-N) and total-phosphorous(T-P) in Korea's Ulsan Area. Using the ecosystem model, we did simulations using a specific set of parameters and did comparative analysis to determine those most appropriate for the actual environmental characteristics of Ulsan Area. The simulation was successful, making it now possible to predict the likelihood of coastal construction projects causing ecological damage, such as eutrophication and red tide. Our model can also be used in the environmental impact assessment (EIA) of future development projects in the ocean.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.3
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• pp.184-195
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• 2005

A preliminary quantitative model of the trophic structure in Gwangyang bay, Korea was obtained using ECOPATH and data from relevant studies to date in the region. The model integrates and analyzes biomass, food spectrum, trophic interactions and the key trophic pathways of the system. The bay model comprises 9 groups of benthic primary producer, phytoplankton, zooplankton, benthos, bivalve, pelagic fish, demersal fish and piscivorous fish. The total system throughput was estimated at $2.4\;kgWW/m^2/yr$, including a consumption of $41\%$, exports of $9\%$, respiratory flows of $24\%$ and flows into detritus of $26\%$. All of which originate from primary producers measured at $52\%$ and detritus of $48\%$. The total biomass was seen to be high compared to the levels of Somme, Delaware, Chesapeake Bays and Seine Estuary. This seems to be possibly due to artificial bivalve aquaculture and overestimation of benthos and benthic primary producer groups. The deviation can be calibrated by neglecting aquaculture and decreasing the habitat area for the groups. The trophic network of the bay shows a low level of recycling and organization as indicated by Finn's cycling index $3.3\%$, Ascendancy $3.1\;kgC/m^2/yr$ bits, Capacity $5.1\;kgC/m^2/yr$ bits and Redundancy $2.2\;kgC/m^2/yr$ bits. A high relative ascendancy of $62\%$ and a low internal relative ascendancy of $18\%$ indicate the system is not fully organized and stable towards disturbances, depending upon external connections. Although the model should be continuously provided with field data and calibrated further in depth, this study is the first trophic model applied to the region. The model can be a useful tool to understand the ecosystem in a quantitative manner.

• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.459-467
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• 2015

Understanding of a carbon storage in a regional scale ecosystem is a very important data for predicting change of global carbon cycle. Therefore, the real data collected in the various ecosystems are a very useful for enhancing accuracy of model prediction. We tried to estimate total accumulated ecosystem carbon in Deogyusan National Park (DNP) with naturally well preserved ecosystem. In DNP, vegetations were classified to four main communities with Quercus mongolica community (12,636.9 ha, 54.8%), Quercus variabilis community (2,987.0 ha, 13.0%), Pinus densiflora community (5,758.0 ha, 25.0%), and Quercus serrata community (402.9 ha,1.7%). Biomass and soil carbons were estimated by the biomass allometric equations based on the DBH and carbon contents of litter and soil (0~30 cm) layers collected in 3 plots ($30cm{\times}30cm$) in each community. The biomass and soil carbons were shown as high value as 1,759,000 tC and 7,776,000 tC, respectively, in Quercus mongolia community in DNP area. In Quercus mongolica, Quercus variabilis, Quercus serrata, Pinus densiflora communities, the accumulated ecosystem carbon were shown 9,536,000 tC, 1,405,000 tC, 147,000 tC, 346,000 tC, respectively. Also, the total ecosystem carbon was estimated with 11,434,000 tC in DNP.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.525-535
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• 1995

The western-style industrial forest management practice involving large scale clearcutting, silviculture with industrially desirable species, and inadequate consideration on ecosystem preservation, has faced severe criticisms from environmentalists, ecologists and conservationists. With an increasing concern about environmental degradation the general public has also been becoming vocal in demanding ecologically sound alternative forest management. An age-old practice of sustainable ecosystem management variously defined as community forestry, social forestry or homestead forestry, has received increased attention in recent days. This type of traditional, and often not very organized method of natural resource management has been practised in many countries from the prehistoric times. It is believed that with a clear understanding of the functioning of ecosystem and community needs, the existing landuse method can be developed into a more productive one. The nature of community forestry management will vary depending on the scale, geographical location, social/community structure and expectations. This article argues that although the rate of economic growth may be lower with community forestry than with industrial forestry, the former fosters the principle of ecosystem sustainability. Industrial forestry may have an initial high growth rate but often it is associated with unsustainable harvesting leading to ecosystem degradation. A review of the traditional methods of economic analyses shows that they do not take into account the many social and environmental costs associated with forestry. It is argued that a well managed community forestry can maintain the critical balance between economic and ecosystem sustainability. An integrated model of community/homestead forestry development is proposed by coordinating the extension services of the departments of agriculture, forestry and environment.

• Ecology and Resilient Infrastructure
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• v.8 no.2
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• pp.120-132
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• 2021

The ecosystem and landscape conservation areas of Seoul were designated according to the Natural Environment Conservation Act and the Natural Environment Conservation Ordinance. With the adoption of the "Rapid Assessment of Wetland Ecosystem Service (RAWES)" approach and the "wetland ecosystem service" for the Ramsar Wetland City Accreditation at the 13th Meeting of the Conference of the Contracting Parties to the Ramsar Convention on Wetlands in 2018, the need for data evaluating wetland ecosystem services has become a necessity. Therefore, in this study, we selected five wetlands from the ecosystem and landscape conservation areas in Seoul, having high ecological conservation values, and evaluated their carbon sequestration and economic value assessment using the InVEST model, which is an ecosystem service evaluation technique. The evaluation results for carbon storage in each wetland are as follows: Tancheon Wetland: 3,674.62 Mg; Bamseom Island in the Hangang River: 1,511.57 Mg; Godeok-dong Wetland: 5,007.21 Mg; Amsa-dong Wetland: 7,108.47 Mg; and Yeouido Wetland: 290.27 Mg. Particularly, the Tancheon Wetland showed the lowest carbon sequestration of 1,130.37 Mg, as compared to the results acquired in 2013, of 4,804.99 Mg. When the average effective carbon rate of $16.06 (US) was applied to the decreased carbon sequestration value, a loss of $15,910.58(US) was calculated. Furthermore, if the average social cost of carbon ($204 (US)) is considered, which includes the impact of climate change on productivity and ecosystems, the total loss is equivalent to $202,101.97 (US). This study aims to examine the natural resource value of urban wetlands by evaluating selected major wetlands in Seoul. This study can be utilized as basic data to plan for the protection and management of the ecosystem and landscape conservation areas. Additionally, because wetland value assessment is considered essential, the results of this study can be used in future research to provide measures for evaluating ecosystem services in the Ramsar Wetland City Certification System. Moreover, this study can be utilized for selecting important wetlands as Ramsar sites, and to raise awareness about the significance of conserving urban wetlands, and for expanding international exchange among the Ramsar Wetland sites.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.6
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• pp.51-64
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• 2022

Along with the urbanization, the risk of urban flooding due to climate change is increasing. Flood regulation, one of the ecosystem services, is implemented in the different level of function of flood risk mitigation by the type of ecosystem such as forests, arable land, wetlands etc. Land use changes due to development pressures have become an important factor in increasing the vulnerability by flash flood. This study has conducted evaluating the urban flood regulation service using InVEST UFRM(Urban Flood Risk Model). As a result of the simulation, the potential water retention by ecosystem type in the event of a flash flood according to RCP 4.5(10 year frequency) scenario was 1,569,611 tons in urbanized/dried areas, 907,706 tons in agricultural areas, 1,496,105 tons in forested areas, 831,705 tons in grasslands, 1,021,742 tons in wetlands, and 206,709 tons in bare areas, the water bodies was estimated to be 38,087 tons. In the case of more severe 100-year rainfall, 1,808,376 tons in urbanized/dried areas, 1,172,505 tons in agricultural areas, 2,076,019 tons in forests, 1,021,742 tons in grasslands, 47,603 tons in wetlands, 238,363 tons in bare lands, and 52,985 tons in water bodies. The potential economic damage from flood runoff(100 years frequency) is 122,512,524 thousand won in residential areas, 512,382,410 thousand won in commercial areas, 50,414,646 thousand won in industrial areas, 2,927,508 thousand won in Infrastructure(road), 8,907 thousand won in agriculture, Total of assuming a runoff of 50 mm(100 year frequency) was estimated at 688,245,997 thousand won. In a conclusion. these results provided an overview of ecosystem functions and services in terms of flood control, and indirectly demonstrated the possibility of using the model as a tool for policy decision-making. Nevertheless, in future research, related issues such as application of models according to various spatial scales, verification of difference in result values due to differences in spatial resolution, improvement of CN(Curved Number) suitable for the research site conditions based on actual data, and development of flood damage factors suitable for domestic condition for the calculation of economic loss.

• ALGAE
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• v.35 no.3
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• pp.237-252
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• 2020

Temperate rocky reefs dominated by the giant kelp, Macrocystis pyrifera, support diverse assemblages of benthic macroalgae that provide a suite of ecosystem services, including high rates of primary production in aquatic ecosystems. These forests and the benthic macroalgae that inhabit them are facing both short-term losses and long-term declines throughout much of their range in the eastern Pacific Ocean. Here, we quantified patterns of benthic macroalgal biomass and irradiance on rocky reefs that had intact kelp forests and nearby reefs where the benthic macroalgae had been lost due to deforestation at three sites along the California, USA and Baja California, MEX coasts during the springs and summers of 2017 and 2018. We then modeled how the loss of macroalgae from these reefs impacted net benthic productivity using species-specific, mass-dependent rates of photosynthesis and respiration that we measured in the laboratory. Our results show that the macroalgal assemblages at these sites were dominated by a few species of stipitate kelps and fleshy red algae whose relative abundances were spatially and temporally variable, and which exhibited variable rates of photosynthesis and respiration. Together, our model estimates that the dominant macroalgae on these reefs contribute 15 to 4,300 mg C m^-2 d^-1 to net benthic primary production, and that this is driven primarily by a few dominant taxa that have large biomasses and high rates of photosynthesis and / or respiration. Consequently, we propose that the loss of these macroalgae results in the loss of an important contribution to primary production and overall ecosystem function.

• Journal of Environmental Impact Assessment
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• v.21 no.3
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• pp.445-460
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• 2012

In order to evaluate and predict the environmental impact of the low-trophic-level ecosystem to environmental changes in the Yellow Sea and the East China Sea, an ecological modelling study was undertaken. Simulation results of average distribution patterns and concentrations of water quality factors during the summer by the model were acceptable. Phytoplankton and remineralization rate of organic matter were very important parameters by a sensitivity analysis. Water quality factors showed high values in the estuary of the Yangtze River and in the West and South Sea of Korea and low values in the central area of the Yellow Sea. There is a plume of high values, especially nutrients, off the mouth of the Yangtze that expands or contracts with changes in the discharge strength. Characteristics of responses of water quality factors vary for different scenarios of environmental change, such as land-based pollution sources and atmospheric forcing. It is suggested that changes of light intensity, discharges of input sources, and wind play an important role in the marine ecosystem.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.185-193
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• 2003

The purpose of this study was attempted to establish concepts of environmental-friendly applications of flood plain and to suggest the application plans. The results of this study can be summarized as follows; 1. Roles of flood plain as biotop (restoration, preservation, and creation of stream corridor ecosystem) should be considered. 2. Application methods considering environmental and scenic values should be reviewed. 3. Application methods reflecting values as regional ecological resources should be planned. 4. Preservation and application should be considered together, and obtaining a means of living for regional residents and creation of economic profits should be considered together. 5. Land application and approach method by usages (integrated management model) should be applied to utilize and manage flood plain efficiently. 6. Flood plain application programs should be designed reflecting opinions of regional residents. 7. With respect to space planning of flood plain, introduction of facilities focused on ecosystem preservation/ecosystem restoration/experiences/observation/learning/culture/ recreation/water purification could be reviewed positively.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.407-417
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• 2020

Entrepreneurship has become an important topic for governments to shape and influence the quantity and quality of entrepreneurship and improve policy toward the entrepreneurial economy. This study investigates the factors affecting the entrepreneurial decision of nascent entrepreneurs belonging to Generation Y in Vietnam. A mixed-method including both qualitative and quantitative methodologies was utilized. A focus group was carried out with 11 participants for exploring, reviewing, and testing content validity of constructs and measurement items. The conceptual model and hypotheses were developed using data collected by a questionnaire survey. The cross-sectional survey method was applied. A sample of 221 respondents was constituted, by both electronic and paper surveys with non-probability and convenience sampling techniques. SmartPLS 3 software was employed to analyze the data collected. The results show that nine factors were affecting the entrepreneurial decision of nascent entrepreneurs belonging to Generation Y in Vietnam, including entrepreneurial education, family background, entrepreneurial ecosystem, perceived behavioral control, social valuation, perceived opportunity, attitude, entrepreneurial self-efficacy, and entrepreneurial intention. The findings show the importance of entrepreneurial education, social value, and ecosystems. Therefore, in order to promote successful entrepreneurship, it is necessary to strengthen entrepreneurship education and have a strategy for the improvement of the entrepreneurship ecosystem.