• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.5
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• pp.373-383
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• 2015

Spatial information has been widely used for efficient land use and management, disaster management, environment management, infrastructure management, corporate marketing, and cultural assets management, and the need for spatial information is expected to be increased. For this reason, central government, local government and public institutions must establish a National Spatial Information System (Fifteen systems related to spatial information managed by National Spatial Data Infrastructure Policy office, NSIS) framework that guarantees high accuracy and quality. The NSIS will provide convenience usage of spatial information in the field of decision-making or civil support. However the current National Spatial Information System is mainly established with separate processes, which causes data redundancy, deterioration of information, passive opening, and sharing of the spatial data. This study suggests 4 standards, which has been derived by applying value-chain model to NSIS data flow, and they are ‘Production and Establishment’, ‘Integration and Sharing’, ‘Application and Fusion’ and ‘Release and Opening’. Based on these standards, the 15 NSIS were analyzed to draw out implications and reforming directions were suggested. By following these suggestions we expect more recent, consist, accurate, and connected National Spatial Information Service which will be more open to public and then satisfy the demands.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.973-977
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• 2003

Land is the only immovable property that can be used, as a means for agricultural production as well as a means for mortgage for financing industrial or commercial enterprises. Spatial technologies play a key role in managing our land, water and natural resources. Cadastral data is a major component for the development of Land Information System. Therefore, systematic land registration system based on accurate and scientific cadastral map are found inevitable for poverty alleviation, good governance and women empowerment through security of their rights on property, as well as the planning and development of a sustainable environmental protection within Metropolitan city. Digital cadastral parcel is the fundamental spatial unit on which database is designed, created, maintained and operated. Availability of accurate and updated cadastral maps is a primary requisite for successful planning, policy formulating and maintenance of city utility services, which need cadastral and utility information together. Flawed cadastral maps can put land, revenue and taxation system at stake. Kathmandu the capital city of Nepal still is lacking utility maps combining cadastral information with the utility. There is an urgent need to have an effective, accurate and easy to access land revenue and utility services system within the urban areas which could be achieved after the production of reliable base maps and land registration system to guarantee land allocation and property rights which can well be achieved by digital conversion and correction of base cadastral maps. This paper highlights the drawbacks of the conventional cadastral maps and the possible advantages of digital cadastral maps over these. Also the problems, issues and implications during digital conversion and creating database of the same will be discussed.

• The KIPS Transactions:PartD
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• v.10D no.2
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• pp.211-220
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• 2003

As Geographic Information Systems represent three dimensional topological information, The Systems provide accurate and delicate services for users. In order to execute three dimensional topological operations, a dimensional transformation and heterogeneous spatial models should be used. However, the existing systems that use the dimensional transformation and the heterogeneous models, is not only difficult to operate the spatial operators, but also happened to support non-interoperability. Therefore, in order to solve the problems, we proposed three dimensional spatial object models that supported two dimensional object models and implemented them to show validity of the proposed models. When designing the three dimensional topological operators, we used 3DE-9IM which extended DE-9IM to support three dimensional concepts, and implemented operators on the component environment with object oriented concepts. The proposed three dimensional spatial object models and topological operators can support interoperability between systems, and execute spatial queries efficiently on three dimensional spatial objects.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.134-137
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• 2005

Unsupervised spectral angle classification (USAC) is the algorithm that can extract ground object information with the minimum 'Spectral Angle' operation on behalf of 'Spectral Euclidian Distance' in the clustering process. In this study, our algorithm uses the unit vector instead of the spectral distance to compute the mean of cluster in the unsupervised classification. The proposed algorithm (MUSAC) is applied to the Hyperion and ETM+ data and the results are compared with K-Meails and former USAC algorithm (FUSAC). USAC is capable of clearly classifying water and dark forest area and produces more accurate results than K-Means. Atmospheric correction for more accurate results was adapted on the Hyperion data (Hyperion-FLAASH) but the results did not have any effect on the accuracy. Thus we anticipate that the 'Spectral Angle' can be one of the most accurate classifiers of not only multispectral images but also hyperspectral images. Furthermore the cluster unit vector can be an efficient technique for determination of each cluster mean in the USAC.

• Spatial Information Research
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• v.23 no.4
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• pp.1-11
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• 2015

Since the Spatial Information Open Platform service started in January 2012, the number of service users and the size of the system has increased significantly. However, we could not know the analysis result about how much the hardware resources of the Open Platform system can handle user services. Thereafter, whenever the number of service users are rapidly increased, we simply have solved the service delays using the hardware extension. So, this study presents the obvious solution to avoid the same problem in the future, by pinpointing the system performance of the Open Platform. In this study, through the performance analysis of hardware using NMON and the load test of web service using nGrinder, we intend to get an accurate performance of the Open Platform system. Then we intend to present the resource reallocation method in order to provide better performance of the system.

• Journal of the Korean Data and Information Science Society
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• v.28 no.1
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• pp.39-47
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• 2017

Precipitation is an important component for hydrological and water control study. In general, AWS data provides more accurate but low dense information for precipitation while radar data gives less accurate but high dense information. The objective of this study is to construct adjusted precipitation field based on hierarchical spatial model combining radar data and AWS data. Here, we consider a Bayesian hierarchical model with spatial structure for hourly accumulated precipitation. In addition, we also consider a redistribution of hourly precipitation to 2.5 minute precipitation. Through real data analysis, it has been shown that the proposed approach provides more reasonable precipitation field.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.83-101
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• 2022

Accurate atmospheric correction is essential for the analysis of land surface and environmental monitoring. Aerosol optical depth (AOD) information is particularly important in atmospheric correction because the radiation attenuation by Mie scattering makes the differences between the radiation calculated at the satellite sensor and the radiation measured at the land surface. Thus, it is necessary to use high-quality AOD data for an appropriate atmospheric correction of high-resolution satellite images. In this study, we examined the Second Simulation of a Satellite Signal in the Solar Spectrum (6S)-based atmospheric correction results for the Sentinel-2 images in South Korea using raster AOD (MODIS) and single-point AOD (AERONET). The 6S result was overall agreed with the Sentinel-2 level 2 data. Moreover, using raster AOD showed better performance than using single-point AOD. The atmospheric correction using the single-point AOD yielded some inappropriate values for forest and water pixels, where as the atmospheric correction using raster AOD produced stable and natural patterns in accordance with the land cover map. Also, the Sentinel-2 normalized difference vegetation index (NDVI) after the 6S correction had similar patterns to the up scaled drone NDVI, although Sentinel-2 NDVI had relatively low values. Also, the spatial distribution of both images seemed very similar for growing and harvest seasons. Future work will be necessary to make efforts for the gap-filling of AOD data and an accurate bi-directional reflectance distribution function (BRDF) model for high-resolution atmospheric correction. These methods can help improve the land surface monitoring using the future Compact Advanced Satellite 500 in South Korea.

• Nuclear Engineering and Technology
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• v.43 no.6
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• pp.531-546
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• 2011

The backward differentiation formula (BDF) method is applied to a three-dimensional reactor kinetics calculation for efficient yet accurate transient analysis with adaptive time step control. The coarse mesh finite difference (CMFD) formulation is used for an efficient implementation of the BDF method that does not require excessive memory to store old information from previous time steps. An iterative scheme to update the nodal coupling coefficients through higher order local nodal solutions is established in order to make it possible to store only node average fluxes of the previous five time points. An adaptive time step control method is derived using two order solutions, the fifth and the fourth order BDF solutions, which provide an estimate of the solution error at the current time point. The performance of the BDF- and CMFD-based spatial kinetics calculation and the adaptive time step control scheme is examined with the NEACRP control rod ejection and rod withdrawal benchmark problems. The accuracy is first assessed by comparing the BDF-based results with those of the Crank-Nicholson method with an exponential transform. The effectiveness of the adaptive time step control is then assessed in terms of the possible computing time reduction in producing sufficiently accurate solutions that meet the desired solution fidelity.

• Journal of Cadastre & Land InformatiX
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• v.46 no.1
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• pp.149-168
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• 2016

This study is aimed to suggest effective ways to precisely manage the public land after searching current problems. Through the utilization of the cadastral organization and the resurvey projects, this study researches the methods to build the accurate land data based on the spatial information system as well as the on-going land survey results of the public land. This study focuses on researching whether the public land status and the management systems are operated efficiently with the cadastral organization using a variety of the spatial systems. This study finds the current problems of the land management systems by not only the Internet questionnaires but several dissertations, and suggests the methods to connect the land management systems with the cadastral resurvey projects each other.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.1
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• pp.49-54
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• 2014

A digital map of 1/5,000 scale provides basic information to be utilized in various businesses, such as in land management, urban information system of a local government, navigation of private sectors and others. 1/5,000 digital map, which contains information of the entire land of South Korea, is performed as a national fundamental map, however, comparing to 1,000 digital map, it has some difficulties in terms of positional accuracy and attribute data for applying in urban areas. Also, since the paradigm of spatial information services has been changed, more accurate positional information and rich attribute information are required for the government businesses and private map services. Particularly, demands for the high precision spatial information based on large-scale digital map is increasing in facility managements due to rapid changes in urban areas and various spatial analyses. For those reasons, this study proposes how to apply and use precise spatial information based on 1/1,000 digital. Firstly, an analysis of legal system related to large-scale digital map and spatial information is conducted in the research. Afterwards, the ways are suggested to improve systematical utilizations of 1/1,000 digital map. We also define existing applications of spatial information in public and private sector, and recommend methodology that can be utilized high precision spatial information.