• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.307-318
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• 2010

This study was to analyze the ecological conditions, based on physical habitat, chemical, and biological conditions before (2006, 2007) and after ecological restoration (2009) in five sites of Changwon Stream (CS) and six sites of Nam Stream (NS), respectively, and then to compare ecological health between the two period. The analysis of ecological health was based on the multimetric models of Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) along with water chemistry in the streams. For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. For the evaluations, the survey was conducted in the period of 2006~2007 before the restoration and in 2009 after the restoration by the city. Chemical conditions, based on conductivity, in both streams showed a typical longitudinal declines along the axis of the upstream-to-downstream. There were no significant differences (p>0.05) in water quality between the two periods. Values of IBI in the CS and NS averaged 21.6 and 19.7, respectively, indicating a C grade in the criteria of Ministry of Environment, Korea, and there was no significant differences in the IBI between the two periods. Values of QHEI after the restoration averaged 29.2 and 63.2 in the CS and NS, respectively and the values decreased markedly especially, in the NS (35.3) after the restoration. The habitat disturbance was mainly attributed to destructions (i.e., the narrower width of riparian vegetation and higher substrate exposure by the air) of artificial materials by massive flood in 2009. Overall, our results suggest that the restoration was not effective in the two streams between the two periods, even if the budget was used a lot and that such ecological restoration, not considered the natural disaster, may not effect for the stream restoration.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.11-27
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• 2017

The road network system of major domestic urban areas such as city of Seoul was rapidly developed and regionally expanded. In addition, many kinds of life-lines such as electrical cables, telephone cables, water&sewerage lines, heat&cold conduits and gas lines were needed in order for urban residents to live comfortably. Therefore, most of the life-lines were individually buried in underground and individually managed. The utility tunnel is defined as the urban planning facilities for commonly installing life-lines in the National Land Planning Act. Expectation effectiveness of urban utility tunnels is reducing repeated excavation of roads, improvement of urban landscape; road pavement durability; driving performance and traffic flow. It can also be expected that ensuring disaster safety for earthquakes and sinkholes, smart-grind and electric vehicle supply, rapid response to changes in future living environment and etc. Therefore, necessity of urban utility tunnels has recently increased. However, all of the constructed utility tunnels are cut-and-cover tunnels domestically, which is included in development of new-town areas. Since urban areas can not accommodate all buried life-lines, it is necessary to study the feasibility assessment system for utility tunnel by urban patterns and capacity optimization for urban utility tunnels. In this study, we break away from the new-town utility tunnels and suggest a quantitative assessment model based on the evaluation index for urban areas. In addition, we also develop a program that can implement a quantitative evaluation system by subdividing the feasibility assessment system of urban patterns. Ultimately, this study can contribute to be activated the urban utility tunnel.

• Economic and Environmental Geology
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• v.50 no.2
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• pp.129-143
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• 2017

The shallow sediments in the southwestern Ulleung Basin consist of mass flow deposits such as slide/slump and debris flow deposits (DFD), caused by slope failure. These sediments are proven to be important in studying geological disaster and stability of the seafloor. In this paper, we analysised the flow accumulation and slope failure susceptibility of the Ulleung Basin on the basis of multi-beam data, collected in this area. We also studied the distribution pattern and the seismic characteristics of the DFD in the uppermost layer of the Ulleung Basin on the basis of seismic data. The slope susceptibility was calculated as the frequency ratio of each factors including slope, aspect, curvature and stream power index (SPI), which causes the slope failure. These results indicate that the slope failure is frequently to occur in the southern and western continental slope of the Ulleung Basin. The sediment flow (mass flow) caused by the slope failure converges to the north and northwest of the Ulleung Basin. According to the seismic characteristics, the uppermost layer in study area can be divided into four sedimentary unit. These sedimentary units develop from the south and southwest to the north and northwest in association with slope susceptibility and flow accumulation.

• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.23-32
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• 1988

Finger injuries are becoming more common with the increasing use of mechanical industrial and household appliances. Among the hand injuries, amputation is the serious disaster to the patient. Recently, application of microsurgical technique to the reattachment of ampuatated digits has been common clinical procedures. We performed microsurgical replantation to the 75 patients with 102 digits from march in 1986 to february in 1988. The following results were obtained. 1. The most common age distribution was third decade and male to female ratio was about 5:1. 2. The ratio of right to left hand was about 1:1 but the dominant to non-dominant hand was about 2:1. 3. The index finger was most commonly injured and the next was middle finger. 4. The most common type of the injuries was the crushing injury and the most common vector was a kind of pressor. 5. The anesthesia was performed in equal ratio between the general and regional anesthesia. 6. The survival rate of microreplantation to the injuries of the zone II was 77.8% and zone III was 80%. 7. The functional result after replantation at zone II was better than zone III. 8. Microreplantation was performed in any case of the type of the injury, the severity of crushing and the ischemic time, and the patients requirement was an important factor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.584-594
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• 2016

This research empirically analyzes, from an ecological perspective, whether socio-economic factors of the regions in which the elderly live have any actual influence on thoughts of suicide on the part of the elderly. Microscopic data either included outliers in part of the variables, including income and other variables of that type, from among source data from investigations into actual conditions of the elderly in 2014. Regarding macroscopic data, the indices that represent social and economic situations in each region, which were provided by KOSIS, were selected. Regarding the method of analysis, hierarchical or multi-level analysis models were applied by considering special hierarchical characteristics and heterogeneity at the personal and regional levels. The analyses showed that the following had statistically significant influences: 1. the cost-of-living index and the national basic supply and demand rate of the region; 2. the extent of natural disaster damage; and 3. the number of leisure and welfare facilities for the elderly, compared to the elderly population. Based on the results, proposals are made for systematic and practical endeavors in the community.

• Journal of the Korean Geographical Society
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• v.50 no.5
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• pp.485-503
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• 2015

This study aims at evaluating geomorphological classification systems to predict the occurrence of landslides in mountainous region in Korea. Geomorphological classification systems used in this study are Catena, TPI, and Geomorphons. Study sites are Gapyeong-gun, Hoengseong-gun, Gimcheon-si, Yeoju-si/Yicheon-si in which landslide occurrence data were collected by local governments from 2001-2014. Catena method has objective classification standard to compare among regions objectively and understand the result intuitively. However, its procedure is complicated and hard to be automated for the general public to use it. Both TPI and Geomorphons have simple procedure and GIS-extension, therefore it has high accessibility. However, the results of both systems are highly dependent on the scale, and have low relevance to geomorphological formation process because focusing on shape of terrain. Three systems have low compatibility, therefore unified concept are required for broad use of landform classification. To assess the effectiveness of prediction on landslide by each geomorphological classification system, 50% of geomorphological classes with higher landslide occurrence are selected and the total landslide occurrence in selected classes are calculated and defined as 'predictive ability'. The ratio of terrain categorized by 'predictive ability' to whole region is defined as 'vulnerable area ratio'. An indicator to compare three systems which is predictive ability divided by vulnerable area ratio was developed to make a comprehensive judgment. As a result, Catena ranked the highest in suitability.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.454-460
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• 2012

This study was conducted for determining the influence of Sediment Control Dam dredging on benthic macroinvertebrate communities in mountain stream of Gyeongsangbuk-do. The sediment control dams were surveyed before and after dredging from mountain streams of Yecheon, Yeongju and Bonghwa in Northern part of Gyeongsangbuk-do. Sampling was taken at upper and down from 3 experimental sites and 2 control sites during May to August 2011. The identified species before dredging were 56 belonged to 31 families, 11 orders, 6 classes and 4 phyla, but after dredging it has decreased to 51 species belonged to 27 families, 10 orders, 5 classes and 4 phyla. The microhabitat damage of benthic macroinvertebrates occurred at experimental sites after dredging of sediment control dams led to reduction of the number of species and individuals. Especially, upper stream of experimental sites showed the reduction of an average of 38% species. In general, species diversity indices and species richness indices decreased after dredging; however, dominance indices increased at experimental sites. In the upper stream of experimental sites, the microhabitat damaged and became pool due to dredging. Also, velocity of flow decreased and the river bed became simply due to the sedimentary matter being finer than sand and silt. As a result, composition of functional feeding groups and functional feeding groups were relatively simpler at upper stream and the degree of community differences was greater between upper and down stream. Also, Chironomidae spp., Ephemeridae spp., and Gomphidae spp. to prefer where slow velocity of flow and lentic increased in a greater rate, and the EPT/C index to indicate the balance of the community decreased.

• Journal of Wetlands Research
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• v.13 no.1
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• pp.1-11
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• 2011

A chronic drought stress has been imposed during non-rainy season(from winter to spring) since 1990s. We faced the most significant water crisis in 2001, and the drought was characterized by sultry weather and severe drought on a national scale. It has been widely acknowledged that the drought related damage is 2-3 times serious than floods. In the list of the world's largest natural disaster compiled by NOAA, 4 of the top 5 disasters are droughts. And according to the analysis from the NDMC report, the drought has the highest annual average damage among all the disasters. There was a very serious impact on the economic such as rising consumer price during the 2001 spring drought in Korea. There has been flood prevention measures implemented at national-level but for mitigation of droughts, there are only plans aimed at emergency (short-term) restoration rather than the comprehensive preventive measures. In addition, there is a lack of a clear set of indicators to express drought situation objectively, and therefore it is important and urgent to begin a systematic study. In this study, a nonstationary downscaling model using RCM based climate change scenario was first applied to simulate precipitation, and the simulated precipitation data was used to derive Standardized Precipitation Index (SPI). The SPI under climate change was used to evaluate the spatio-temporal variability of drought through principal component analysis at three different time scales which are 2015, 2045 and 2075. It was found that spatio-temporal variability is likely to modulate with climate change.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.193-210
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• 2013

This study aims to assess the slope stability variation of Jeollabuk-do drainage areas by RCM model outputs based on A1B climate change scenario and infinite slope stability model based on the specific catchment area concept. For this objective, we downscaled RCM data in time and space: from watershed scale to rain gauge scale in space and from monthly data to daily data in time and also developed the GIS-based infinite slope stability model based on the concept of specific catchment area to calculate spatially-distributed wetness index. For model parameterization, topographic, geologic, forestry digital map were used and model parameters were set up in format of grid cells($90m{\times}90m$). Finally, we applied the future daily rainfall data to the infinite slope stability model and then assess slope stability variation under the climate change scenario. This research consists of two papers: the first paper focuses on the methodologies of climate change scenario preparation and infinite slope stability model development.

• Fire Science and Engineering
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• v.29 no.2
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• pp.25-32
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• 2015

The improved thermal stability and anti-oxidation properties of lyocell fiber were studied based on flame retardant treatment by using $Na_3PO_4$ solution. The optimized conditions of flame retardant treatment were studied on various concentrations of $Na_3PO_4$ and the mechanism was proposed through experimental results of thermal stability and anti-oxidation. The integral procedural decomposition temperature (IPDT), limiting oxygen index (LOI) and activation energy ($E_a$) increased 30, 160% respectively via flame retardant treatment. It is noted that thermal stability and anti-oxidation improved based on char and carbon layer formation by dehydrogenation and dissociation of C-C bond resulting the hindrance of oxygen and heat energy into polymer resin. The optimized conditions for efficient flame retardant property of lyocell fiber were provided using $Na_3PO_4$ solution and the mechanism was also studied based on experimental results such as initial decomposition temperature (IDT), IPDT, LOI and $E_a$.