• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.95-104
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• 2002

In this study, a reliability-based design (RBD) procedure for determining design values fur anchored sheet pile wall is proposed considering overturning about the anchor point as the major failure mode. In this design procedure, the depth of embedment of the sheet pile wall is logically chosen in accordance with degrees of uncertainties of design input parameters using approximate probabilistic computation methods. These methods have been successfully used in the geotechnical engineering requiring neither understandings of complex probabilistic theories nor efforts to prepare more data. It was investigated that the design results by the proposed method were compatible with those by commonly used deterministic design methods. Additionally, in an effort to investigate the effects of changes in the degree of uncertainties of major design variables on the design results of the sheet pile wall, a sensitivity analysis was peformed.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.818-837
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• 2018

Technological innovation has inherent difficulties, largely due to the uncertainties of technology. Thus, the forecasting methodology to reduce the risk of uncertainty in the innovation process has been presented both in quantitative and qualitative fields. On the other hand, big data and artificial intelligence have attracted great interest recently, and deep learning, which is one of the algorithms of AlphaGo, is showing excellent performance. In this study, deep learning methodology was applied to the prediction of innovation performance. To make the prediction model, we used KIS 2016 data. The input factors were importance of information source and innovation objectives and the output factor was innovation performance index, which was calculated for this study. As a result of the analysis, it can be confirmed that the accuracy of prediction is improved compared with the previous studies. As learning progressed, the degree of freedom of prediction also improved.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.3 s.37
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• pp.55-62
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• 2006

The purpose of the current research is to evaluate the possibility of landslides by using geo-spatial information system. Geological information has been summarized and stability analysis for infinite slopes has been conducted based on the force equilibrium. In addition, the analysis of landslides was performed based on probabilistic approach by using probabilistic variables which can include uncertainty of input parameters. For the purpose of testifing the applicability of the analysis method actual geological data from a construction site was obtained, thereby performing both a preliminary analysis for a large area and detailed analysis for a better result. As a result of the current analysis several issues such as the possibility of development of landslides, detailed analysis of where landslides are most likely to be developed were analysed by using two concepts of safety and index of failure probability.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.6 no.9
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• pp.111-124
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• 1983

The basic model of decision problem the enterprise is conforonted with includes the following 3 elements ; 1) Elements that can not be controlled by the decision maker : In the thesis elements are named environmental variables, and varied itself according to the change of environmental condition. 2) Elements that can be controlled by the decision maker ; These elements are called decision elements in the thesis and variable according to the event. 3) object of decision making : The degree of achievement to the object is identified by taking various criteria- The index indicating the degree of achievement to the object whatever criterion is applied is called object function in the thesis. It's the fanetion of environmental variable, decision variable and object function. The relation between them brings forth the relation formula that characterize the each problem. The basic types of decision making model use in the thesis are as following ; 1) The problem of decision making under conditions of certainty. 2) The problem of decision making under conditions of risk. 3) The problem of decision making under conditions of uncertainty. 4) The problem of decision making under competitive condition. in general case that the Profit of two decision makers varies, what we regard the decision that make the sum of profit of two men maximum as the best choice for two men has a reasonability in certain case. When the sum of profit two men is zero, by taking toe promise that ail of them art according to the min-max criteria and by extending the object of choice to the mixed strategy. We certify the existance of equilibrium solution and admit them as the best solution of competitive model in general.

• Journal of the Korean Geotechnical Society
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• v.34 no.6
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• pp.25-36
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• 2018

Soil liquefaction is one of the types of major seismic damage. Soil liquefaction is a phenomenon that can cause enormous human and economic damages, and it must be examined before designing geotechnical structures. In this study, we proposed a practical method of developing a multi-hazard fragility surface for liquefaction of levee considering earthquake magnitude and water level. Limit state for liquefaction of levee was defined by liquefaction potential index (LPI), which is frequently used to assess the liquefaction susceptibility of soils. In order to consider the uncertainty of soil properties, Monte Carlo Simulation based probabilistic analysis was performed. Based on the analysis results, a 3D fragility surface representing the probability of failure by soil liquefaction as a function of the ground motion and water level has been established. The prepared multi-hazard fragility surface can be used to evaluate the safety of levees against liquefaction and to assess the risk in earthquake and flood prone areas.

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.115-122
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• 2010

The importance of the life cycle cost (LCC) analysis for bridges has been recognized over the last decade. However, it is difficult to predict LCC precisely since the costs occurring throughout the service life of the bridge depend on various parameters such as design, construction, maintenance, and environmental conditions. This paper presents a methodology for the optimal life cycle cost design of a bridge. Total LCC for the service life is calculated as the sum of initial cost, damage cost, maintenance cost, repair and rehabilitation cost, user cost, and disposal cost. The optimization method is applied to design of a bridge structure with minimal cost, in which the objective function is set to LCC and constraints are formulated on the basis of Korean Bridge Design Code. Initial cost is calculated based on standard costs of the Korea Construction Price Index and damage cost on damage probabilities to consider the uncertainty of load and resistance. Repair and rehabilitation cost is determined using load carrying capacity curves and user cost includes traffic operation costs and time delay costs. The optimal life cycle cost design of a bridge is performed and the effects of parameters are investigated.

• Korean Journal of Remote Sensing
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• v.26 no.1
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• pp.29-38
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• 2010

It is necessary to develop an integration model which can account for various data acquired at different measurement scales in environmental thematic mapping with high-resolution ground survey data and relatively low-resolution remote sensing data. This paper presents and applies a multi-scale geostatistical methodology for downscaling of thematic maps generated from lowresolution remote sensing data. This methodology extends a traditional ordinary kriging system to a block kriging system which can account for both ground data and remote sensing data which can be regarded as point and block data, respectively. In addition, stochastic simulation based on block kriging is also applied to describe spatial uncertainty attached to the downscaling. Two downscaling experiments including SRTM DEM and MODIS Leaf Area Index (LAI) products were carried out to illustrate the applicability of the geostatistical methodology. Through the experiments, multi-scale geostatistics based on block kriging successfully generated relatively high-resolution thematic maps with reliable accuracy. Especially, it is expected that multiple realizations generated from simulation would be effectively used as input data for investigating the effects of uncertain input data on GIS model outputs.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.148-148
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• 2018

Land subsidence caused by excessive groundwater pumping is a serious hydro-geological hazard. The spatial variability in land use, unbalanced groundwater extraction and aquifer characteristics are the key factors which make the problem more difficult to monitor using conventional methods. This study uses the European Space Agency (ESA) Sentinel satellites to investigate and monitor land subsidence varying with different land covers and groundwater use in the arid Quetta valley, Pakistan. The Persistent Scattering Differential Interferometry of Synthetic Aperture Radar (PS-DInSAR) method was used to develop 28 subsidence interferograms of the study area for the period between 16 Oct 2014 and 06 Oct 2016 using ESA's Sentinel-1 SAR data. The uncertainty of DInSAR result is first minimized by removing the dynamic effect caused by atmospheric factors and then filtered using the radar Amplitude Dispersion Index (ADI) to select only the stable pixels. Finally the subsidence maps were generated by spatially interpolating the land subsidence at the stable pixels, the comparison of DInSAR subsidence with GPS readings showed an R 2 of 0.94 and mean absolute error of $5.7{\pm}4.1mm$. The subsidence maps were also analysed for the effect of aquifer type and 4 land covers which were derived from Sentienl-2 multispectral images. The analysis show that during the two year period, the study area experienced highly non-linear land subsidence ranging from 10 to 280 mm. The subsidence at different land covers was significantly different from each other except between the urban and barren land. The barren land and seasonally cultivated area show minor to moderate subsidence while the orchard and urban area with high groundwater extraction rate showed excessive amount of land subsidence. Moreover, the land subsidence and groundwater drawdown was found to be linearly proportional to each other.

• Journal of Environmental Science International
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• v.30 no.2
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• pp.153-159
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• 2021

This study aims to suggest the direction of urban regeneration policies of Gangwon-do in accordance with COVID-19 outbreak, and the results are as follows. First, it is inevitable to urgently execute the project from the perspective of cities and counties in Gangwon-do, where the promotion of urban regeneration projects has been delayed due to COVID-19 incident. As a result, it is highly likely to cause the employees overloaded and have negative effect on achieving the goals of urban regeneration, so, it is necessary to provide support measures at the government and provincial level, such as the actual execution index and the adjusting time of start and completion of particular business. Second, as the uncertainty of COVID-19 continues, it needs to strengthen the operation and monitoring of urban regeneration support centers in Gangwon-do and examine the changes in business operation plans in advance. In particular, the decrease in visitors to traditional markets and restaurants is expected to have a direct effect on small business owners engaged in the service industry. Therefore, it is necessary to actively consider the utilization plans of smart city regeneration, such as online shopping and non-contact payment. Third, it is necessary to phase in smart urban regeneration training focused on information weakness to narrow the digital gap, in preparation for general lifestyle changes such as contactless and non-face-to-face interactions. At a time when new light is being shed on local areas, which are quieter than heavily populated cities, a project that reflects the regional characteristics and culture of Gangwon-do is necessary.

• International Area Studies Review
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• v.16 no.1
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• pp.147-171
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• 2012

Even though many people loosely term a period of high inflation combined with stagnation "stagflation", it has been very difficult for us to find a more detailed and theoretical definition for such a period. In addition, most economic policy makers have faced some uncertainty and difficulty in identifying stagflation periods through analyzing a lot of economic data. This paper deeply researches the literature on specific definitions of stagflation and provides an empirical method by which we can systematically identify real-time stagflation pressure. Under this method, real-time stagflation pressure can be evaluated as a complex index by using both extensive monthly economic data indicating economic conditions or inflation pressure and a logit regression model. As a result of applying this method to the first half of 2008 in Korea when there was much debate as to whether the Korean economy was experiencing a corresponding stagflation or not, this period is not now evaluated as having been a stagflation period. This paper provides some implications. Namely, we need to put more emphasis on stabilizing inflation expectations.