• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.1
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• pp.1-11
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• 2000

The hybrid coding algorithm for multi-spectral image obtained from satellite is discussed. As the spatial and spectral resolution of satellite image are rapidly increasing, there are enormous amounts of data to be processed for computer processing and data transmission. Therefore an efficient coding algorithm is essential for multi-spectral image processing. In this paper, VQ(vector quantization), quadtree decomposition, and DCT(discrete cosine transform) are combined to compress the multi-spectral image. VQ is employed for predictive coding by using the fact that each band of multi-spectral image has the same spatial feature, and DCT is for the compression of residual image. Moreover, the image is decomposed into quadtree structure in order to allocate the data bit according to the information content within the image block to improve the coding efficiency. Computer simulation on Landsat TM image shows the validity of the proposed coding algorithm.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.2
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• pp.65-79
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• 2003

In this study GIS based pre- and post-processing tool for the Visual MODFLOW that is specific software to model groundwater flow is developed. This tool not only makes input data scientifically but also manages input and output data in terms of the groundwater flow analysis. In addition it can storage project products systematically into Oracle database. The most characteristic figure of this processing tool is to provide the module, which automatically or semi automatically develops various grid cell sizes using GIS ArcView and also produces DXF files reflecting various boundary conditions in the modeling zone. In particular, eminences of this research are to create 3 dimensional hydrogeological structures with 2 dimensional GIS ArcView and to conduct pre- and post- processing along with same topology and data format of the MODFLOW.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.64-75
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• 2008

Since the current database systems for managing geotechnical investigation results were limited by being described boring test result in point feature, it has been trouble for using other GIS data. Although there are some studies for spatial characteristics of subsurface modeling, it is rather lack of being interoperable with GIS, considering geotechnical engineering facts. This is reason for difficulty of practical uses. In this study, we has developed subsurface spatial information model through extracting needed geotechnical engineering data from geotechnical information DB. The developed geotechnical information clustering program(GEOCL) has made a cluster of boring formation(and formation ratio), classification of layer, and strength characteristics of subsurface. The interpolation of boring data has been achieved through zonal kriging method in the consideration of spatial distribution of created cluster. Finally, we make a subsurface spatial information model to integrate with digital elevation model, and visualize 3-dimensional model by subsurface spatial information viewing program(SSIVIEW). We expect to strengthen application capacity of developed model in subsurface interpretation and foundation design of construction works.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.35-45
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• 2007

Currently, the necessity of inter-system integration and sharing system increases to additionally construct and efficiently utilize the geographical information data in accordance with the increase in demand for geographical information. The provision of the data within the domestic sharing system is led by the tasks within national geographical information distribution network or intra-local governmental combined system. However, any voluntary geographical information sharing cooperation body is increasingly required with the increase in necessity of administrative cooperation among neighboring metropolitan areas, including space planning and development. Accordingly, this study is aimed at looking into the constitutions and roles of cooperation bodies within metropolitan areas by the composition, distribution, update and management of data with special regard to overseas advanced cases whose sharing systems and their effects are highly evaluated, and at presenting any model of the domestic future voluntary sharing cooperation organization within metropolitan area.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.4
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• pp.63-72
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• 2000

The objective of this study was to identify the applicability of AGNPS(Agricultural Nonpoint Source Pollution) model using RS data; Landsat TM merged by KOMPSAT EOC and GIS data. AGNPS model which is well-known distributed nonpoint source pollution model was used as the assessment tool. This model has the capability to adjust the level of pollutant load from farmstead and the fertilization level of upland field. A small agricultural watershed($4.12km^2$) which has 20 livestock farmhouses located in Gosan-myun, Ansung-gun was selected. AGNPS data were prepared by using Arc/Info, GRASS, ER-Mapper and Idrisi. Four storm events in 1999 were used for runoff calibration, and 2 storm events which were measured in hourly-base at 4 locations along the stream were used for water quality(TN, TP) calibration.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.2
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• pp.29-36
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• 2004

The purpose of this study is to analyze DMB(digital multimedia broadcasting) technologies of transmitting GIS-based traffic information for developing DMB systems compared with FM DARC(FM data radio channel). R&D and standardizations for transmitting GIS-based traffic information have been rapidly changed, as radical developments in ITS(intelligent transportation systems), telemaics, and communication methods such as ubiquitous and convergences of broadcasting and communications. Each communication method employs different GIS format, protocol, and standardizations, i.e., GML(geography markup language) and TPEG(transport protocol experts group). This paper presents technical methods and trends of transmitting traffic information using broadcasting along with FM DARC, in general, and DMB, in particular.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.3
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• pp.73-82
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• 2003

This paper proposes a work procedure for generalizing large-scale digital maps ver. 2.0(1/5,000) into a small-scale digital map(1/25,000). Unlike a existent digital map, the digital map ver. 2.0 has a variety of attribute data as well as graphic data. To perform an efficient map generalization with these structural properties, we establish a work procedure as follow; firstly, delete layers which don't exist in small-scale digital map's feature code, and secondly, generalize features which have been classified into 8 layers, and finally merge 8 layers which have been generalized into 1 layer. Therefore, we expect that a work procedure which is proposed in this paper will play a fundamental role in automated generalization system and will contribute to small-scale digital mapping and thematic mapping.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.4
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• pp.133-142
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• 2004

As the city grows in population and size, land-use plan increasingly becomes a crucial element in developing a city-wide plan. In the process of developing the land use plan, identifying the present conditions and predicting the future conditions are the most important steps. That is, to understand the phenomena of land-use activities as well as to manage uses of the land efficiently require the comprehensive land use information system. This study intends to construct the land use database utilizing the Cadastral Map and Registered Building Data and to examine and suggest the application areas of the database. The database was constructed with those of Busan Metropolitan City. Using the established data, it shows how to use the database to identify the present conditions in Busan.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.2
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• pp.141-151
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• 2013

This study presents a modeling of aerosol extinction vertical profiles in Korea by using the Moderate Resolution Imaging Spectro-radiometer(MODIS) derived aerosol optical thickness(AOT) and ground based visibility observation data. The method uses a series of physical equations for the derivation of aerosol scale height and vertical profiles from MODIS AOT and surface visibility data. The modelled results under the standard atmospheric condition showed small differences with the standard aerosol vertical profile used in the radiative transfer model. Model derived aerosol scale heights for two cases of clean(${\tau}_{MODIS}=0.12{\pm}0.07$, visibility=$21.13{\pm}3.31km$) and hazy atmosphere(${\tau}_{MODIS}=1.71{\pm}0.85$, visibility=$13.33{\pm}5.66km$) are $0.63{\pm}0.33km$ and $1.71{\pm}0.84km$. Based on these results, aerosol extinction profiles can be estimated and the results are transformed into the KML code for visualization of dataset. This has implications for atmospheric environmental monitoring and environmental policies for the future.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.2
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• pp.138-146
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• 2011

With the increased use of GPS in the field of various applications including surveying, the request for fast and precise positional information has increased. Several countries such as USA, Canada, and Australia have already been operating Internet-based automatic GPS data analysis system using e-mail and FTP. Expanding GPS market, it is necessary to establish automatic GPS baseline processing system that is accessible via Internet. The system developed in this study is operating on the web, and it allows the users to access easily regardless of time and place. The main processing engines are Bernese V5.0 and PAGES. They process user data with three GPS CORS(Continuously Operating Reference Station), and then send the report to the users through e-mail. This system allows users to process high accurate GPS data easily. It is expected that this system will be used for various GPS applications such as monitoring large-scale structures and providing spatial information services in private sector.