• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.652-656
• /
• 2007

The major streams in South Korea have established the TMDL(Total Maximum Daily Loads) regulation for just 4 years. Traditional concepts in water quality management in South Korea are based upon the selection of a design streram flow which is 10-year averged flow exeedance probability 75%(Q275). That is, a single flow value based upon average long term flow conditions is chosen for application in dilution calculations, permit design, water quality modeling, etc. While these TMDLs seems to satisfy the requirement of the target water quality regulations, they have contributed little to any watershed/waterbody assessment and restoration plans. These types of TMDLs do little to characterize the problems the TMDLs are intended to address. For TMDLs to be more beneficial in the assessment and implementation process, TMDLs should reflect adequate water quality across flow conditions rather than at a single flow value such as average daily flow. In this paper, we developed LDC (load duration curve) methodology for theevaluation of Korean TMDL evaluation based on watershed scaled, physically based on SWAT(Soil and Water Assessment Tool) model.

• Spatial Information Research
• /
• v.10 no.4
• /
• pp.501-513
• /
• 2002

Eurasian otter (Lutra lutra) is one of endangered wildlife species whose population size is declining in Korea. To manage and conserve habitat for Eurasian otter, it is crucial to understand which habitat components affect otter habitat qualities. The objectives of this study were to develop a habitat suitability model of Eurasian otter in Soraksan National Park, to validate the model in Odaesan National Park. The research methods of this study were as follows. First, trace data and characters of Eurasian otter habitat were collected with Geographic Information System (GIS) data and Global Positioning System (GPS) receivers between 2000 and 2002. Second, the habitat use factors were identified as habitat characteristics of Eurasian otter and classified with habitat use and availability analyses. Third, significant factors of habitat model were extracted by Chi-square test. The last, Eurasian Otter Habitat Suitability Model (EOHSM) was employed by logistic regression method. Otter habitat use was positively associated with the reeds and shrubs areas adjacent to streams, the size of boulders, and low human disturbance in Soraksan National Park by EOHSM. This model had a classification accuracy of 74.4% at cutoff value of 0.5. Model validation showed a classification accuracy of 86.6 % at cut off value of 0.5 for otter habitat in Odaesan National Park.

• Korean Journal of Environmental Biology
• /
• v.26 no.4
• /
• pp.330-342
• /
• 2008

A comprehensive quality survey for PCDDs/PCDFs and coplanar PCBs as well as heavy metals (Cu, Zn, Cd and Pb) in sediments has been investigated in August 2006, Korea. Monitoring was undertaken at five streams representing different surrounding environments throughout Juwang and Gapyeong streams (reference sites), Jungrang stream (dense population site), Ansan stream (mixed small population and industrial site), and Siheung stream (heavy industrial site). The levels of heavy metal in samples were found to be significantly higher in sediment from Siheung stream compared to those of other stream sites. The heavy metal concentrations (dry weight basis) in sediment from Siheung stream were as follows; Cd (3.7 ${\mu}g$/g), Pb (1,295 ${\mu}g$/g), Cu (713.4 ${\mu}g$/g) and Zn (358.1 ${\mu}g$/g). Among 12 coplanar PCBs and 17 PCDDs/PCDFs selected as target compounds in this study, PCB (IUPAC no. 118) and OCDD were the most abundant congeners found in all sediment samples, followed by 1,2,3,4,6,7,8-HpCDD, OCDF and 1,2,3,4,6,7,8HpCDF as well as PCB (IUPAC no. 105). These results were shown to be in the same trend as the sediment samples of other countries. The levels of PCDDs/PCDFs/coplanar PCBs in sediment samples were expressed as concentrations and WHO- TEQ values. The PCDDs/PCDFs/coplanar PCBs concentrations and their WHO-TEQ values in sediment from Siheung stream were remarkably high. The levels detected were 788.16 pg/g and 36.080 pg WHO-TEQ/g dry weight for PCDDs/ PCDFs and 314 pg/g and 0.4189 pg WHO-TEQ/g dry weight for coplanar PCBs, respectively, beyond the safety level of sediment value 20 pg WHO-TEQ/g. Sediment samples of the five streams were also monitored by sensitive biomarkers using insect immune responses: hemocyte-spreading behavior and immune-associated enzyme activities of phospholipase A$_2$ (PLA$_2$) and phenoloxidase. Organic extracts of Siheung and Jungrang sediments significantly interfered with the hemocytespreading behavior, whereas those of Ansan, Gapyeong, and Juwang did not. These organic extracts did not inhibit the PLA$_2$ and phenoloxidase activities. However, phenoloxidase was highly susceptible to exposure to aqueous extracts in all site sediments. In comparison, PLA$_2$ activities of the hemocytes were significantly inhibited only by aqueous extracts of Siheung, Jungrang, and Gapyeong sediments, but not by those of Ansan and Juwang. Despite some disparity between bioand chemical monitoring results, the biomarkers can be recommended as a device warning the contamination of biohazard environmental chemicals because of a fast and inexpensive detection method.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.17 no.4
• /
• pp.29-41
• /
• 2014

The Korean government has purchased land properties alongside any significant water bodies before setting up the buffers to secure water qualities. Since the annual budgets are limited, however, there has always been the issue of which land parcels ought to be given the priority. Therefore, this study aims to develop efficient mechanism for land acquisition priorities in stream corridors that would ultimately be vegetated for riparian buffer zones. The criteria of land acquisition priority were driven through literary review along with experts' advice. The relative weights of their value and priorities for each criterion were computed using the Analytical Hierarchy Process(AHP) method. Major findings of the study are as follows: 1. The decision-making structural model for land acquisition priority focuses mainly on the reduction of non-point source pollutants(NSPs). This fact is highly associated with natural and physical conditions and land use types of surrounding areas. The criteria were classified into two categories-NSPs runoff areas and potential NSPs runoff areas. 2. Land acquisition priority weights derived for NSPs runoff areas and potential NSPs runoff areas were 0.862 and 0.138, respectively. This implicates that much higher priority should be given to the land parcels with NSPs runoff areas. 3. Weights and priorities of sub-criteria suggested from this study include: proximity to the streams(0.460), land cover(0.189), soil permeability(0.117), topographical slope(0.096), proximity to the roads(0.058), land-use types(0.036), visibility to the streams(0.032), and the land price(0.012). This order of importance suggests, as one can expect, that it is better to purchase land parcels that are adjacent to the streams. 4. A standard scoring system including the criteria and weights for land acquisition priority was developed which would likely to allow expedited decision making and easy quantification for priority evaluation due to the utilization of measurable spatial data. Further studies focusing on both point and non-point pollutants and GIS-based spatial analysis and mapping of land acquisition priority are needed.

• Korean Association of Arts Management
• /
• no.58
• /
• pp.179-204
• /
• 2021

Not only the consumption trend after the COVID-19 pandemic but also low financial interest rates have stimulated people to invest artworks. With the recent noticeable growth, art investments that mainly conducted by younger generation through online platform can be characterized by a fractional ownership in art market which means several people share one piece of artwork. This study explores 4 fractional ownership platforms in the domestic art market including Art Together, Art & Guide, Tessa, and Pica projects, using a business model canvas that describes nine key elements: Customer Segments, Value Proposition, Channels, Customer Relationships, Revenue Streams, Key Resources, Key Activities, Key Partners and Cost Structure. The four cases have similar business models, but the details of revenue streams are different. The key sources of revenue are the profit and commission of the work. Thus, maximizing the profit margin of artworks is the core of revenue streams, so selecting and purchasing highly profitable artworks are significant. Based on the analysis, there are 3 suggestions to continue fractional ownership platform businesses in art market successfully. First, it is required to have a long-term perspective on art investments, as a way to diverse asset portfolio. Second, business confidence should be increased to maintain customer loyalty. Third, the role of platforms as competent experts is important.

• Journal of Korean Society on Water Environment
• /
• v.24 no.3
• /
• pp.317-327
• /
• 2008

This study developed the methodology to calculate the total daily maximum load (TMDL) using the instreamflow requirement because the previous TMDLs were too simple to easily achieve. Instreamflow requirement which was the average low flow ($Q_{275}$) in the previous planning cannot consider the seasonal variation of streamflow. Therefore, this study used the instreamflow requirement which is a maximum value among hydrologic drought flow ($Q_{355}$), and environmental flows for ecology and scenery. The environmental flows for ecology were calculated using Physical HABitat SIMulation system (PHABSIM) which can estimate the necessary flow for fish survival by life cycle. Using the proposed method, all monthly TMDLs of streams in the Anyangcheon were calculated for the application.

• Journal of Environmental Science International
• /
• v.26 no.8
• /
• pp.881-891
• /
• 2017

In this study, the discharge loads of non-point pollution sources were analyzed using a Hydrologic Simulation Program-Fortran (HSPF) model for 46 sub-watersheds in order to guide the management plan for water and streams passing through the city. The results using HSPF showed good applicability in comparison to point measurements, which were based on BOD, TP, and TN. The mean value of the BOD loads was $4.08kg/km^2$ per day, and the highest level of BOD was $17.75kg/km^2$ per day at Namri. Three potential areas of high priority for the installment of constructed wetlands were selected in order to reduce non-point pollution sources based on BOD loads and on environmental and economic conditions. The results for these scenarios indicated a maximum rate of reduction in BOD of 39.12% within the proposed constructed wetlands.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.22 no.7
• /
• pp.937-945
• /
• 1998

The purpose of this paper is to investigate the relationship between pressure recovery and turbulent characteristic value of velocity and pressure, in the case where a swirling flow streams into a conical diffuser. The results of both measurements of the wall pressure fluctuation and velocity fluctuation revealed them to role the large part of the total pressure loss of the flow. The cause of the fluctuation of flow was showed to be the flow separation at the inlet of diffuser at low intensity of swirl, but the flow of diffuser center was instable at high intensity of swirl. The static pressure recovery depends strongly on the magnitude of the turbulent energy in the diffuser, and that this magnitude of the turbulent energy varies as the intensity of swirl at the diffuser inlet.

• Microbiology and Biotechnology Letters
• /
• v.27 no.2
• /
• pp.159-165
• /
• 1999

Pseudomonas aeruginosa JRT-4 strain was used as a biosurfactant-producing microorganism in this study. It was one of the microorganisms isolated from the sewage sludge, the main and branch streams of Han river. The surface tension of the culture broth of P. aeruginosa JRT-4 decreased to 30mN/m. The crude biosurfactant was obtained from the culture broth by acid precipitation, solvent extraction, evaporation, and freeze drying. The CMC value of the crude biosurfactant was 0.006%(w/v). From analysis of the chemical structure of biosurfactant, it was determined as rhamnolipid 1 and 3 structures by FAB mass spectrometer. In the washing test for artificially contaminated textiles, the biosurfactant showed better bleachness than the two chemically synthesized surfactant, LAS and SLES. Finally, the biodegradation and ecotoxidolorical tests showed that the biosurfactant was readily biodegradable in the environment and a mild material for microorganisms and green algae.

• Management & Information Systems Review
• /
• v.25
• /
• pp.171-201
• /
• 2008

Previous research on negative contents of verbal message being more influential has a two broad streams as impression formation theory and negative information having an more diagnostic informational value. Therefore, this research was intended to obtain consistent results from researches by message frame segmentation of verbal message and to determine the medium of verbal message. It was proven from the research that objects influencing verbal message are being effected by the participation ratio of products and the positive indication is having more meaningful difference than the negative indication statistically unlike to the results of previous researches. Unlike just a biased positive message or negative message as the result of previous research, it was proven that the positive indication is influential regardless of sequences according to participation ratio and site participation in case of positive and negative being existing together.