• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.3
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• pp.188-202
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• 2011

Due to emissions of greenhouse gases caused by increased use of fossil fuels, the climate change has been detected and this phenomenon would affect even larger changes in temperature and precipitation of South Korea. Especially, the increase of temperature by climate change can affect the amount and pattern of snowfall. Accordingly, we tried to predict future snowfall and the snowfall pattern changes by using the downscaled GCM (general circulation model) scenarios. Causes of snow varies greatly, but the information provided by GCM are maximum / minimum temperature, rainfall, solar radiation. In this study, the possibility of snow was focused on correlation between minimum temperatures and future precipitation. First, we collected the newest fresh snow depth offered by KMA (Korea meteorological administration), then we estimate the temperature of snow falling conditions. These estimated temperature conditions were distributed spatially and regionally by IDW (Inverse Distance Weight) interpolation. Finally, the distributed temperature conditions (or boundaries) were applied to GCM, and the future snowfall was predicted. The results showed a wide range of variation for each scenario. Our models predict that snowfall will decrease in the study region. This may be caused by global warming. Temperature rise caused by global warming highlights the effectiveness of these mechanisms that concerned with the temporal and spatial changes in snow, and would affect the spring water resources.

• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.574-582
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• 2005

Localization in wireless sensor networks is essential to important network functions such as event detection, geographic routing, and information tracking. Localization is to determine the locations of nodes when node connectivities are given. In this paper, centroid approach known as a distributed algorithm is extended to a centralized algorithm. The centralized algorithm has the advantage of simplicity. but does not have the disadvantage that each unknown node should be in transmission ranges of three fixed nodes at least. The algorithm shows that localization can be formulated to a linear system of equations. We mathematically show that the linear system have a unique solution. The unique solution indicates the locations of unknown nodes are capable of being uniquely determined.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.259-268
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• 2004

For supporting Interoperability among heterogeneous data sources in different geographic information systems, it is required to use open API like OGIS OLE DB Proposed in OGC. The OLE/COM Implementation Specification of OGIS only provides interfaces to discover and access spatial data, but does not support interfaces for updating distributed spatial data. To solve this problem, we propose and add interfaces for updating spatial objects distributed over heterogeneous data sources and examining the consistency of spatial relationships between updated objects. We also devise a 2-phase commit protocol based on spatial relationships in order to guarantee the consistency of updated objects. To justify the update scheme using the proposed Interfaces and 2-phase commit prototype we design and implement a prototype system for updating distributed spatial objects.

• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.235-247
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• 2010

An environmental factor is very important in a war game model supporting military training. Most war game models in Korean armed forces apply the same weather conditions to all operation areas. As a result, it fails to derive a high-fidelity simulation result. For this reason this study attempts to develop factor techniques for a high-fidelity war game that can apply distributed synthetic atmospheric environment modeling data to a military simulation. The major developed factor technology of this study applies regional distributed precipitation data to the 2D-GIS based Simplified Detection Probability Model(SDPM) that was developed for this study. By doing this, this study shows that diversely distributed local weather conditions can be applied to a military simulation depending on the model resolution from theater level to engineering level, on the use from training model to analytical model, and on the description level from corps level to battalion level.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.4
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• pp.113-124
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• 2009

A research of grid computing that is the combination of computer resources from multiple distributed administrative domains to get large amount of computing power is underway. This research is an application of grid technology on a urban facilities management system based on u-GIS. The sensors are set up in the urban facilities to make it monitoring. If an amount of sensors and gateways is increased, the server needs more computing resources to process the data. In this study we developed the skills that can distribute jobs to idle gateway, in case of the server capacity had approached threshold. It will be possible to develop of economic and efficient system that will apply to large amount of data processing about u-City.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.4
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• pp.158-168
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• 2009

As nation and society progresses, urban ground facilities and their management system get more complicated and the cost and effort to control the system efficiently grows exponentially. This study suggests to the deployment method of a sensor node by Wireless Sensor Network for controling the Urban Ground Facilities of National Facilities. First, we achieve the management facilities and method using the first analysis and then make the coverage of sensing and then set up the Sensor Node in Urban Ground Facilities. Second, we propose the solution way of repetition by the second analysis. And, we embody the GIS program by Digital Map and this method, we improve the reality by overlapping an aerial photo. Also we make an experience on the sensor node allocation using making program. we can remove the repetition sensor node about 50%, and we can confirm that the sensor nodes are evenly distributed on the road.

• Water Engineering Research
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• v.1 no.3
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• pp.223-231
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• 2000

The purpose of this study is the development of a system for estimating non-point sources pollutant loads from a watershed, which enables users to get insights of pollutant load distribution in the watershed during rain as well. Based on the Geographic Information System, this non-point source pollutant loading estimation system(NSPLES) consists of three distinct models such as a distributed rainfall-runoff model, a soil loss and delivery model, and a non-point source pollutant model. It also includes GIS modules for preprocessing the input data for the models and graphical postprocessing of the model outputs. The system output aren't only the hydrograph, sedimentograph, and pollutograph at the watershed outlet, but also various maps that show the distribution of soil loss over the watershed. The developed system was applied to the two upper stream areas of Sumjin river basin, Ssangchi and Gwanchon basins, and three rainfall events for respective subbasins during 1992 and 1998 were selected for the system application. The results of this showed relatively higher corelation between observed data and simulated data, and proved the applicability of the system.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.107-110
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• 2002

A grid computing environment is one in which applications can be built over multiple resource nodes at widespread geographic locations. Grid environments seek to integrate and enable access to widely distributed compute resources. The compute resources in a grid environment are typically heterogeneous, with varying qualify and availability Hence, how computations are allocated to individual resources is extremely important in the design of a grid. This paper j\ulcorners concerned with resource management for metacomputing. We describe a resource management architecture using the two-level resource broker.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.69-81
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• 2009

Using a computational fluid dynamics (CFD) model, the effects of building complexes constructed under an urban renewal plan on air flows in an urban area were investigated. For this, the geographic information system (GIS) data were used as the input data of the CFD model and four experiments were numerically simulated for different inflow directions (westerly, southerly, easterly, and northerly cases). Before constructing building complexes under the urban renewal plan, wind speed at the pedestrian level was very low around buildings because of decrease in wind speed by the drag effect of the densely distributed low-rise buildings. As the high-rise buildings were constructed and building density decreased by the urban renewal plan, wind speed at the pedestrian level increased compared to that before the urban renewal plan because the drag effect by the buildings decreases and the channeling effect satisfying the mass continuity partially appeared at the spaces among the high-rise buildings. At the upper levels, wind speed partially increased inside the high-rise buildings due to the channeling effect but it remarkably decreased across a vast extent of the downwind regions due to the generation of the recirculation zone and the drag effect of the high-rise buildings.

• Water Engineering Research
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• v.3 no.2
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• pp.85-92
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• 2002

There has been continuous efforts to manage water resources for the required water quality criterion at river channel in Korea. However, we could obtain the partial improvement only for the point sources such as, waste waters from urban and factory site through the water quality management. Therefore, it is strongly needed that the best management practice throughout the river basin fur water quality management including non-point sources pollutant loads. This problem should be resolved by recognizing the non-point sources pollutant loads from the upstream river basin to the outlet of the basin depends on the landuse and soil type characteristics of the river basin using the computer simulation by a distributed model based on the detailed investigation and application of Geographic Information System (GIS). The purpose of this study is consisted of the three major distributions, which are the investigation of spread non-point sources pollutants throughout the river basin, development of the base maps to represent and interpret the input and outputs of the distributed simulation model, and prediction of non-point sources pollutant loads at the outlet of a up-stream river basin using Agricultural Non-Point Sources Model (AGNPS). For the validation purpose, the Seom-Jin River basin was selected with two flood events in 1998. The results of this application showed that the use of combined a distributed model and an application of GIS was very effective fur the best water resources and quality management practice throughout the river basin