• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.811-822
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• 2019

Environmental flows in the downstream sections of Yongdam Dam, Wonju Stream Dam, and Hongcheon River were estimated with selected target fish species such as Nigra for the site of Yongdam Dam, Splendidus for the site of Wonju Stream Dam, and Signifer for the site of Hongcheon River by considering endangered and domestic species. Physical habitat analysis was performed to estimate environmental flows for the study sites by applying the Physical Habitat Simulation (PHABSIM) and RIVER2D which combined hydraulic and habitat models. Based on the monitored data for ecological environment, the Habitat Suitability Index (HSI) for the target species was estimated by applying the Instream Flow and Aquatic Systems Group (IFASG). In particular, based on the result of fish monitoring, the HSI for each stage of the growth for target species was analyzed. As a result, the Weighted Usable Area (WUA) was maximized at $4.9m^3/s$ of flow discharge during spawning, $5.8m^3/s$ during the period of juvenile, and $8.9m^3/s$ during the adult fish season at the downstream section of Yongdam Dam. The result of the Wonju Stream Dam showed an optimal environmental flow of $0.4m^3/s$, $1.0m^3/s$, and $1.5m^3/s$ during the period of spawning, juvenile, and adult. The habitat analysis for the site of Hongcheon River, which is a non-regulated stream, produced an optimum environmental flow of $5m^3/s$ in the spawning period, $4m^3/s$ in the juvenile stage and $6m^3/s$ in the adult stage.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.327-341
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• 2021

The riparian eco-belt is an efficient technique that can reduce non-point pollution sources in the basin and improve ecological connectivity and health. In Korea, a legal system for the construction and management of riparian eco-belts is in operation. However, it is currently excluded that rivers and floodplains in dam reservoir that are advantageous for buffer functions such as control of non-point pollutants and ecological habitats. Accordingly, this study presented and analyzed a plan to select a site for an integrated riparian ecol-belt that comprehensively evaluates the water quality and ecosystem characteristics of each dam floodplain and riparian zone for the Daecheong Dam basin in Geum River watershed. First, the Daecheong Dam basin was divided into 138 sub-basin with GIS, and the riparian zone adjacent to the dam floodplain was analyzed. Sixteen evaluation factors related to the ecosystem and water quality impact that affect the selection of integrated riparian eco-belt were decided, and weights for the importance of each factor were set through AHP analysis. The priority of site suitability was derived by conducting an integrated evaluation by applying weights to sub-basin by floodplains and riparian zone factors. In order to determine whether the sites derived through GIS site analysis are sutiable for actual implementation, five sites were inspected according to three factors: land use, pollution sources, and ecological connectivity. As a result, it was confirmed that all sites were appropriate to apply integrated riparian ecol-belt. It is judged that the riparian eco-belt site analysis technique proposed through this study can be applied as a useful tool when establishing an integrated riparian zone management policy in the future. However, it might be necessary to experiment various evaluation factors and weights for each item according to the characteristics and issues of each dam. Additional research need to be conducted on elaborated conservation and restoration strategies considering the Green-Blue Network aspect, evaluation of ecosystem services, and interconnection between related laws and policy and its improvements.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.94-106
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• 2022

In order to increase timber self-sufficiency, Korea's 6th Basic Forest Plan aims to increase the density of forest roads to 12.8 m ha^-1 by 2037. However, due to rapid re-forestation, current management infrastructure is insufficient, with just 4.8 m ha^-1 of forest roads in 2017. This is partly due to time and cost limitations on the process of forest road feasibility evaluation, which considers factors such as topography and forest conditions. To solve this problem, we propose an eco-friendly and efficient forest road network planning method using a geographic information system (GIS), which can evaluate a potential road site remotely based on spatial information. To facilitate such planning, this study identifies forest road construction priorities that can be evaluated using spatial information, such as topography, forest type and forest disasters. A method of predicting the optimal route to connect a forest road with existing roads is also derived. Overlapping analysis was performed using GIS-MCE (which combines GIS with multi-criteria evaluation), targeting the areas of Cheongsong-gun and Buk-gu, Pohang-si, which have a low forest-road density. Each factor affecting the suitability of a proposed new forest road site was assigned a cost, creating a cost surface that facilitates prioritization for each forest type. The forest path's optimal route was then derived using least-cost path analysis. The results of this process were 30 forestry site recommendations in Cheongsong-gun and one in Buk-gu, Pohang-si; this would increase forest road density for the managed forest sites in Cheongsong-gun from 1.58 m ha^-1 to 2.55 m ha^-1. This evaluation method can contribute to the policy of increasing timber self-sufficiency by providing clear guidelines for selecting forest road construction sites and predicting optimal connections to the existing road network.

• Journal of Environmental Impact Assessment
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• v.24 no.3
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• pp.233-243
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• 2015

The ecosystem fragmentation due to transportation infrastructure causes road-kill phenomenon. When making policy for reducing road-kill it is important to select target-species in order to enhance its efficiency. However, many corridors installed in Korea have been raised issues about their effectiveness due to lack of considerations such as target-species selection, site selection, and management, etc. In this study, we are to grasp relationship between road-kill area and habitat patches and suggest that spatial location of habitat patches should be considered as one of the important factors when making policy for reducing road-kill. Habitat patches were presumed from overlying suitability index that chosen by literature review and road-kill hotspot was determined by Getis-Ord $G_i^*$ analysis. Afterwards, we performed a correlation analysis between $G_i$ Z-score and the distance from habitat patches to the roads. As a result, there is a negative correlation between two variables, It affects the $G_i^*$ Z-score going up if the habitat patches and the roads become closer.

• Journal of Korean Academy of Nursing
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• v.25 no.4
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• pp.617-632
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• 1995

Nowadays, most big hospitals have a computer system to manage their administration. For maxi mum effectiveness in managing the computer system, an analysis of the variables affecting its implementation is necessary from the beginning. This study was done to analyze the variables influencing the operation of a hospital information system (HIS). The theoretical base for this study considered the combined effects of user expectations of computerization, and computer-anxiety. The relationship between variables in the theoretical base were analyzed and the individual characteristics influencing each variable were also analyzed. This study was done in two steps. First, 344 nurses were given an initial questionnaire developed to evaluate the reliability of the items. Based on the results, a second revised questionnaire was administered to 88 nurses who had been working in the areas where HIS was applied. The results of the first and second steps of the study are as follows 1. The initial study was done with nurses who were trained on the computer system briefly before HIS was implemented. The individual characteristics influencing computer anxiety and expectation regarding computer system usage in that initial study included, length of career, type of degree or certification, previous experiences with a computer, training on a computer, desire for computer training, and level of acceptance of a computerized work environment. But in the second study with nurses working in areas of the hospital where HIS was introduced, the work site was the only influencing characteristics. There-fore, in applying a computer system, overcoming work-environment barriers will be more import-ant than any individual characteristics. 2. The computer anxiety of the nurses in both groups, before and after the computer system ap-plication, was below the average level but the expectation of the effects of computerization was above average. The nurses using the computer program showed an above average level of satis-faction with the computer system itself, and with its effect on their efficiency. Therefore, the ability of nurses operating HIS will be positively. predictive. 3. For the variables included in the theoretical framework of the study, all of the correlational coefficients were statistically significant in the analysis of variation correlation. Therefore, the theoretical base of the study, "expectation in con junction with computer anxiety" can be considered an model which can be evaluated. Accord-ing to our analysis, the higher the level of nurses' motivation to use the computer system and the lower the anxiety about computer usage, the higher the possibility of computer system acceptance by nurses. The results of this study showed that in applying a computer system in the hospital, the main characteristic influencing acceptance was where the individual worked rather than personal characteristics such as length of career, type of degree or certification, and previous experiences with a computer. Therefore, it is suggested that the first step in uncovering and eliminating hindrance factors in ap-plication of a computer system should be an analysis of working conditions in relation to the functional content of the computer system. The suitability of the theoretical model based on the hypothesis ap-plied in this study should be further tested.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.1
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• pp.66-73
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• 2015

Alveolar bone loss and deformation can be a risk factor in removable prosthetic restoration treatment for partially or fully edentulous patients. The use of implants to solve this problem could improve the support, retention and stability of removable restoration. Attachments used in implant overdenture are versatile. The attachment should be selected according to the patients' conditions. Milled bar has been chosen when readymade bar could not be used because of the narrow distance between implants or firm stability and support of supra-structure were needed. Milled bar design is able to provide cross arch stabilization and comfortability to patients. However, it needs skilled laboratory procedures. Recently, the fabrication of milled bar has become simple and its suitability has been improved through the development of CAD/CAM system. In a 67-year-old female Alzheimer's disease patient with 8 implant fixtures on the fully edentulous site of mandible, implant overdenture with using milled bar and magnet attachment was planned. As rapid treatment was required, CAD/CAM system was used to make a simple laboratory procedure instead of a traditional fabrication process. With this system, implant overdenture with milled bar can be fabricated esthetically and functionally.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.723-730
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• 2016

Domestic Manila clam production has been reduced due to coastline changes and environmental degradation, but aquaculture industry is facing difficulties caused by an increase in imports. It is important to recognize the integral habitat environment in order to do sustainable aquaculture. The habitat environment of Manila clams (Ruditapes philippinarum) is closely related to the productivity of aquaculture farms. This study investigated 3 indexes, survival (sediment type, hydrodynamic), growth (Chlorophyll a, DIN, DIP) and environment (water temperature, dissolved oxygen, sediment chemical oxygen demand, ignition loss) as indicators of habitat characteristics for a tidal flat farm in Geunso Bay (Pado and Beopsan) from June 2015 to May 2016. As a result, Pado (maximums.; sand 48.76 %, hydrodynamic 10.59 cm/s, Chlorophyll a 12.70 ug/L, exposure time 3 hours, DO 18.65 mg/L) had a higher sand content, faster current speed, more abundant nutrients and DO, providing more favorable conditions for Manila clams than Beopsan (maximums.; sand 37.40 %, hydrodynamic 6.02 cm/s, Chlorophyll a 6.41 ug/L, exposure time 7 hour, DO 14.81 mg/L). In fact, Pado showed a higher density than Beopsan. This study considered the habitat environments of Pado and Beopsan to provide a basis for optimal management practices and potential suitable sites in Geunso bay.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1075-1086
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• 2008

In order to investigate the applicability and suitability of the industrial by-products to apply mono-layer cover system for non-sanitary landfill sites, 6 different industrial by-products, such as construction waste, bottom ash, gypsum, blast furnace and steel manufacture slags, and stone powder sludge, were evaluated. Various physicochemical and hydrodynamic properties of the industrial byproducts were investigated. The environmental safety was monitored using batch and long-term leaching tests as well. In addition, the flexibility of plants was observed by cultivating them in the industrial by-products. The results for physicochemical properties indicate that most of the materials considered appeared to be suitable for landfill cover. Particularly, the concentration levels of hazardous elements regulated by the Korean Law for Waste Management did not exceed the regulatory limits in all target materials. In addition, the concentrations of regulated elements for the Korean Soil Conservation Law were examined below the regulatory limits in most of materials considered, except for the stone powder sludge. The results of batch and long-term experiments showed bottom ash and construction waste were the most suitable materials for landfill cover among the industrial by-products considered. The results of plant studies indicate that the bottom ash among industrial by-products considered was most effective in developing vegetation on landfill site, showing fast germination and large growth index. At the final covering system made of mixture of soil and bottom ash, the optimum application rate of farmyard manure was observed to be 40-50 Mg/ha.

• Journal of Environmental Science International
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• v.22 no.8
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• pp.925-935
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• 2013

In this study, a comprehensive field monitoring was conducted to understand habitat conditions of fish species in up and downstream of Hoengseong Dam. Based on the monitoring data, riverine health conditions such as composition ratio of fish species, bio-diversity (dominance index, diversity, evenness and richness), index of biological integrity (IBI) and qualitative habitat evaluation index (QHEI) were assessed, and optimal ecological flowrates (OEF) were estimated using the habitat suitability indexes (HSI) established for three fish species Coreoleuciscus splendidus, Pungtungia herzi and Microphysogobio longidorsalis selected as icon species using the physical habitat simulation system (PHABSIM). The total number of species sampled was 20 species, and two species of Zacco platypus (30.4%) and C. splendidus (20.9%) dominated the fish community. As a result, it was revealed that IBI and QHEI values decreased from upstream to downstream along the river. The estimated IBI value ranged from 24 to 36 with average being 30.9 out of 50, rendering the site ecologically fair to good health conditions. HSI for C. splendidus were determined according to three different month in terms of season: Spring (April), Summer (August) and Autumn (October). HSI for flow velocity were estimated at 0.7 to 0.8 m/s for the Spring, 0.5 to 1.0 m/s for the Summer and 0.8 to 0.9 m/s for the Autumn. HSI for water depth were estimated at 0.3 to 0.5 m for the Spring; 0.3 to 0.5 m for the Summer; and 0.3 to 0.4 m for the Autumn. OEF was estimated at 4.2 and $6.5m^3/s$ for the Spring and Autumn, and $12.0m^3/s$ for the Summer. Overall, it was concluded that the Hoengseong Dam has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.328-335
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• 2000

Seasonal and vertical variations of organic carbon and chemical oxygen demand (COD$_{Mn}$ were investigated to estimate a suitability of COD$_{Mn}$ methods as an index of the quantity of organic matter in Lake Soyang. Organic matter in the lake may be composed matters resistant to oxidation by COD$_{Mn}$ method, especially in de데 layers. Rations of COD$_{Mn}$ to TOC varied with season and depth layer in Lake Soyang. In the inflowing river, the ratios after summer monsoon were very low and significantly different compared with other seasons (p<0.0001 between after summer monsoon and other seasons by unpaired sample t-test). At the dam site the ratio was low in the deep layer. The ratios in deep layer were significantly different compared with those of upper and middle layers (p<0.0001 by paired sample t-test). In Lake Soyang COD$_{Mn}$ yielded only 40$ of TOC and the oxidation rate of COD$_{Mn}$ varied largely with season and depth. These results implied that the COD$_{Mn}$ does not seem to be an index or organic matter in lakes.