• Economic and Environmental Geology
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• v.38 no.1
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• pp.33-43
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• 2005

The purpose of this study is to make and validate landslide susceptibility map using artificial neural network and GIS in Kangneung area. For this, topography, soil, forest, geology and land cover data sets were constructed as a spatial database in GIS. From the database, slope, aspect, curvature, water system, topographic type, soil texture, soil material, soil drainage, soil effective thickness, wood type, wood age, wood diameter, forest density, lithology, land cover, and lineament were used as the landslide occurrence factors. The weight of the each factor was calculated, and applied to make landslide susceptibility maps using artificial neural network. Then the maps were validated using rate curve method which can predict qualitatively the landslide occurrence. The landslide susceptibility map can be used to reduce associated hazards, and to plan land use and construction as basic data.

• Computers and Concrete
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• v.20 no.6
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• pp.635-643
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• 2017

The rehabilitation and strengthening of concrete structures using Fiber-Reinforced Polymer (FRP) materials have been widely investigated. As a priority issue, however, the effect of curing conditions on the bonding behavior between FRP and concrete structures is still elusive. This study aims at developing a prediction model to accurately capture the mode-II interfacial debonding between FRP strips and concrete under different curing conditions. Single shear debonding experiments were conducted on FRP-concrete samples with respect to different curing time t and temperatures T. The J-integral formulation and constrained least square minimization are carried out to calibrate the parameters, i.e., the maximum slip $\bar{s}$ and stretch factor n. The prediction model is developed based on the cohesive model and Arrhenius relationship. The experimental data are then analyzed using the proposed model to predict the debonding between FRP and concrete, i.e., the interfacial shear stress-slip relationship. A Finite Element (FE) model is developed to validate the theoretical predictions. Satisfactory agreements are obtained. The prediction model can be used to accurately capture the bonding performance of FRP-concrete structures.

• Journal of Korean Society on Water Environment
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• v.37 no.1
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• pp.20-31
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• 2021

In this study, an analysis of the characteristics of organic matter and nitrogenous oxygen demand (NOD) of 17 sewage effluent and wastewater treatments was conducted. High CODMn and carbonaceous biological oxygen demand (CBOD) concentrations were observed in the livestock treatment plants (LTP), wastewater treatment plants(WTP), and night soil treatment plants (NTP), but the highest NOD concentration and contribution rates of NOD to BOD5 were found in sewage treatment plants (STP). There was no significant difference in the CBOD/CODMn ratio for each of the six pollution source groups, but the LTPs, WTPs, and NTPs all showed relatively high CODMn concentrations in their effluent samples, indicating that they are facilities which discharge large amounts of refractory organic matter. The seasonal change of NOD in all facilities' effluent was found to be larger than the seasonal change of CBOD, and data results also revealed an elevation of NOD and NH3-N concentration from December to February, when the water temperature was low. There was no significant difference in NH3-N concentration in relation to pollution source group (p=0.08, one-way ANOVA), but the STP, which had a high NOD contribution rate to BOD5 of 48%, showed a high correlation between BOD5 and NOD (r2=0.95, p<0.0001). These results suggest that the effect of NOD on BOD5 is an important factor to be considered when analyzing STP effluent.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.389-397
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• 2018

Recently, Global Shale gas development has expanded, increasing shale gas production has transformed the energy market.As a result of the reduction of energy facilities, in order to overcome the management deterioration of domestic casting valve industry and enter the enlarged shale gas plant, tried to confirm the SWOT factor through the second questionnaire based on the questionnaire survey of related industry experts and previous studies. As a strength-strategy, presented three factors besides collaboration with domestic companies, suggested four factors including product development specialized in shale gas plant as a weakness complement. Thesis offer to scholarly-Practical implications, Internal-external environmental factors, strategization for entering New energy market. thesis offer to scholarly, Practical implications, environmental factors, strategization for entering New energy market. After, analyze a important of research strategy, would like to study the impact on the company according to the ranking of importance.

• Journal of Climate Change Research
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• v.4 no.4
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• pp.317-330
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• 2013

The yield of rice production is affected severely by abnormal weather events, such as flood, drought, high temperature etc. The objective of this paper is to assess impacts of abnormal weather events on rice production, using a panel model which analyzes both cross-section data and ti- me series data. Abnormal weather is defined as the weather event which goes beyond the range of ${\pm}2{\sigma}$ from the average of a weather factor. The result of an analysis on impacts of high temperature on rice production showed that the yield of rice was decreased 5.8% to 16.3% under the conditions of extremely high temperature, and it was decreased 8.8 to 20.8% under the conditions of both extremely high and heavy rain. Adaptation strategies, development of new varieties enduring high temperature and heavy rain, adaptation of crop insurance, modernization of irrigation facilities are needed to minimize the impacts of abnormal weather on rice production, and to stabilize farmers' income.

• Journal of the Korean GEO-environmental Society
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• v.19 no.12
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• pp.33-39
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• 2018

In this study, important characteristics were identified for the Geosynthetic-soil interface using overburden pressure and saltwater and fresh water to evaluate silt shear behavior of the Geosynthetic-soil interface. In addition, waste landfill can secure spaces for waste disposal in the sea and this spaces can be used for additional facilities which will be necessary in the future. Analysis of behavior characteristics on interface of Geosynthetic-soil shows that, if analyzed using standard consolidometers, the consolidation stress of fresh water increased significantly more than saltwater. When analyzed using cyclic shear apparatus, saltwater and freshwater in both conditions, the displacement value increases as the wire gauges become closer to the lower module, and the shear fracture tends to occur radically under saltwater conditions than fresh water. Therefore, seawater, fresh water that act on the interface of geosynthetic-soil, and installation of facility using geosynthetic should be considered as important parameters that are essential for the dynamic design factor of the water controlling facility.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.5
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• pp.699-715
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• 2019

Recently, in urban areas, cavities and ground collapse adjacent to underground structures are frequently reported. Several studies on the cavity generation by structure cracks have been made, however they are focused on the cause of cracks and settlement of the ground. In this paper, soil particle and groundwater discharge through pipe cracks and cavity generation mechanism are investigated. The theoretical analysis of the groundwater, which is the main factor of the drainage of the soil particles, and the particle transport mechanism and flow characteristics were investigated. An experimental model test was carried out to identify the mechanism of cavity generation by underground buried pipe cracks. The soil particle weight of discharge through the cracks, and the movement characteristics of the particles were analyzed using PIV. In this study, it is clearly identified that soil particle movements, cavity generation and ground collapse that occur in the ground are basically caused by the movement of groundwater.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.1
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• pp.1-11
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• 2019

This study suggested that various stakeholder can be participated in regional Environment planning and practical use of policy with rapid assessment of Ecosystem Services(ES). We applied to the rapid assessment of ES method to Ansan city and local registers selected Ecosystem assets that considered to space of ES. Ecosystem assets were measured 5 types Likert scale about 37 indicators of ES and confirm the main ES through the basic statistics. Furthermore Ecosystem assets classified according to similar character of ES. Ecosystem assets of Ansan were selected 47 site and Local climate regulation, Research and education, Primary production was high among the ES indicators. As a result two main group deduced that ecological education group(such as Research and education, Habitat) and safety regulation group(such as Air regulation, Fire regulation) through the factor analysis. In terms of location characteristics of each group, the ecological education-centered ecosystem assets were located near the downtown area, while the safety regulation group was located at the outskirts, such as mountains and coasts. This indicates that the ecological education about the habitat provision can be achieved in Ansan city downtown area and that outskirts should be approached from the aspect of ecological function to establish a plan. The result of Rapid assessment of ES, which can be lead a balanced and developmental consultation when establishing polices for environment planning and management in region.

• The Korean Journal of Franchise Management
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• v.11 no.1
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• pp.19-29
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• 2020

Purpose - To understand the assessment basis of customers' coffee shop experience and give more practical advices to the franchised coffee shops which are poorly managed in the competitive market, this study identified factors to measure the quality of customer experience and explored the relationship between these factors and customer satisfaction and loyalty. Further, this study analyzed which role self-efficacy played in the structural relationship between the quality assessment factors, satisfaction and loyalty of franchised coffee shops. Research design, data, methodology - The data were collected from respondents who had visited franchised coffee shops within the previous month through online survey. The questionnaires were surveyed from February 11 to February 14, 2019. A total of 318 responses were collected after excluding four of incomplete or uncandid responses. A structural equation modeling approach was used to examine the proposed hypothesis and a confirmatory factor analysis was employed to verify the four dimensions of quality assessment. Results - The findings of this study are as follows. First, the three of quality assessment variables significantly influenced on satisfaction except environmental quality. Second, economic and service quality significantly influenced on self-efficacy but environmental and menu quality didn't. Third, satisfaction significantly influenced on loyalty but not on self-efficacy. Fourth, self-efficacy significantly influenced on Loyalty. Conclusions - This study identified the four dimensions to assess the franchised coffee shop service - menu, environment, service and economic quality and verified these four dimensions are valid as indicators to measure the quality of customers' coffee shop experience. Further, by empirically testing the structural relationships among these quality assessment dimensions, satisfaction, self-efficacy and loyalty, this study provided theoretical foundations to explore the relationship between customer and the franchised stores in restaurant businesses. For the industry, the study findings showed that customers highly appreciated menu and economic quality of the service rather than the stores' interior. This indicate that the franchised coffee shops need to focus more on the basics of coffee such as taste and menu variety and economic value than the decoration of the store, which are often over-invested nowadays.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.55-61
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• 2011

Recently, a concept of the downtown area was progressively extended by improvement of rapid transportation system and development of the most advanced telecommunication industries. And underground has become bigger in addition deeper, Excavation methods which construct a structure were changed according to construction environments. Top Down methods which are continuous with architectural plan differ from existing excavation methods innovatively, pre-founded column is an important factor for construction methods, duration, expenses. Therefore, this study considers application by investigative methods according to comparison, analysis on loading test result of on site inspection and estimated results of bearing capacity for structure pre-founded column. As a result, almost designing eclipse appeared prior value which didn't arrive result of load test. Also, evaluate permanent load for the compressive stress acting on head of cast-in-place after basic structure was installed. Then, applying stress generally is reduced by confining effect with foundation.