• Journal of Korean Society for Geospatial Information Science
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• v.17 no.2
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• pp.133-143
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• 2009

Next Generation Digital Maps on demand Updating System is a system for setup of efficient on-demand updating system, keeping up-to-date data and conducting high-quality service and efficient management. The system is designed that object-based continuous Digital Maps may have on-demand updating available, as well as the exiting feature-based digital maps, and the relevant development is being done. This study presented some problems and improvement plans related to the system operation, by means of implementing object-based continuous Digital Maps and feature-based digital maps updating test, for the next generation digital maps on demand updating system, in order to contribute to present plans to apply next generation digital maps and to secure competitiveness. And, for the economical efficiency of the next generation digital maps on demand updating system, this study analyzed expenses and benefit resulted from introduction of on demand updating system for 1:5,000 digital maps, intended for National Geographic Information Institute. and the land category which have an effect on the officially assessed land price and it using GIS technology.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.51-63
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• 2008

It is important to develop standard metadata to give more plentiful information about the forest cover type map and to promote distribution by National Geographic Information Clearinghouse. In this study metadata for the forest cover type map was designed based on TTAS.IS-19115 and it consisted of 10 packages and 50 elements. Also metadata editor was developed to implement metadata with standard schema and metadata viewer to service more user friendly interface. This work was about the first standard metadata for forest GIS data. So it would be a useful reference to develop metadata for other digital map concerning forest.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.4
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• pp.357-363
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• 2001

Recently, structure and type of GIS data is various and complicated. Therefore, there is a research on efficient data collecting and processing method. Digital maps and orthophotos are needed for efficient usage in the field of GIS. Digital maps which are one of the part of NGIS and digital cadastral maps are different, and data construction isn't performed. Furthermore, there are no research on the improvement of difference between digital maps and cadastral maps. In this paper, manufactured digital orthophotos using aerial photos are used for change detection in a central area of a town. Selecting a town which has various changes, and digital maps and cadastral maps overlap each other, and analyze them for correction, renovation and possible application.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.29-40
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• 2012

The method regarding obtaining various kinds of attribute data of spatial information, including that of digital map, is normally restricted to Geographic survey that deals with in-field surveys. Geographic surveying for drawing digital map, however, require much effort due to the fact that a surveyor has to characterize geographic features individually in the field. Not only does the Geographic survey cover large area, but also its need for manual drawing and surveying using Draft map makes it more expensive and time-consuming. Though some recent Geographic surveys take advantage of MMS(Mobile Mapping System) to collect computerized information, there are inevitable limits in creating digital map with such data. This research will analyze the problems in current Geographic surveys and suggest adequate methods and standards for Geographic surveys by researching the methods of domestic/international service organizations that deal with establishing spatial information. This study therefore will aim to enhance the efficiency of creating digital map and Geographic survey, which would ultimately maximize the applicability of pan-national digital map by improving reliability of digital map and upgrading the utilizability of Geographic survey data.

• Journal of Power System Engineering
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• v.16 no.5
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• pp.40-46
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• 2012

For free surface flow problem, a high-order spectral/boundary element method is adapted as an efficient numerical tool. This method is one of the most efficient numerical methods by which the nonlinear gravity waves can be simulated and hydrodynamic forces also can be calculated in time domain. In this method, the velocity potential is expressed as the sum of surface potential and body potential. Then, surface potential is solved by using the high-order spectral method and body potential is solved by using the high-order boundary element method. Using the combination of these two methods, the free surface flow problems of a submerged moving body are solved in time domain. In the present study, lifting surface theory is added to the former work to include effects of lift force. Therefore, a new formulation for the basic mathematical theory is introduced to contain the lift body in calculation.

• Journal of Korean Society for Geospatial Information Science
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• v.8 no.2 s.16
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• pp.35-46
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• 2000

The digital maps, important data to build NGIS, require different scales in the same area. The organization for producing a digital map tries to find product method for digital map with economical efficiency and quality. The objectives of this study is to develope digital map generalization system to solve above problems. In order to develop this system, the work processing for digital map generalization is established, the analysis of related law and analysis on maps in different scales were performed, and each of digital map generalization algorithms was compared. The result of digital map generalization using this system shows that have a good result about positional accuracy which was evaluated by comparison between the generalized 1/25,000 and the corresponding 1/5,000 digital map. Furthermore, this system reduce the time required for 1/25,000 digital map production and the physical data amount by around 80%. In conclusion, the generalization system developed for this research can be useful for the digital map generalization from large scale to small scale digital map.

• Journal of Korean Society for Geospatial Information Science
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• v.8 no.1 s.15
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• pp.85-95
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• 2000

There is a recent emphasis on the need for updating and revision of existing digital maps as more digital maps are used and produced. Various type of data sources, such as photographs, ground surveyed data and satellite images, are used in the revision and the updating process. The process is very time consuming and costly, especially for small regional areas. This study, attempts to present an effective update/revision method using the as-built surveying drawings and the accuracy of the digital map which has been updated and revised using this method was also investigated. This study showed that by using as-built surveying drawings of scale 1/1,200 to update a digital map of scale 1/1,000, the resulting accuracy satisfied the requirements of the national digital map accuracy specification for the corresponding scale. The necessity of the existence of the necessary drawings and maps is a requirement of this process and it is also suggested that densification of local control points especially in the urban areas is necessary for producing accurate as-built surveying drawings. This would require the establishment of rules and regulations which would require constructions to perform as-built surveying, immediately after the construction has been completed.

• Spatial Information Research
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• v.7 no.2
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• pp.255-269
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• 1999

This is an experimental study to translate the Korean digital topographic maps into distributable information-hide objects, which are designed with object-oriented development's key features ; encapsulation, polymorphism, inheritance, In order to achieve this goal , the characteristics of the data mode and inter-relationships of digital topographic maps are investigated . As a result, it is revealed that the current Korean digital topographic maps, which is organized into so many individual layers of mixed spatial and attributed data, have to explicit and concrete hierarchies in spatial data model and data definition . Due to this limitation , data layer stage and object class stage are integrated. And ISCO(the is-computer -of relationships) mechanism is mainly used to develop the objects of digital topogrpahic maps, which is implemented with spatial primitive classes. the designed objects are coded with JAVA and then testified in web interface.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.1
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• pp.9-17
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• 2007

In this study, Digital Elevation Models (DEMs) were constructed from color images, grayscale images and each bands (Red, Green, Blue) of color image, and the accuracies of each DEMs were evaluated, And then, correlation coefficients between left and right images of each stereopairs were analyzed. The DEM can be constructed conventionally from the digital map and stereopair images using image matching. The image matching requires stereo satellite images or aerial photographs. In case of rotor aerial photographs, these are to be scanned in 3 bands (Red, Green, Blue). For this study, 5 types of images were acquired; color, grayscale, RED band, GREEN band, and BLUE band image. DEMs were constructed from 5 types of stereopair images and evaluated using elevation points of digital maps. In order to analyze the cause of various accuracies of each DEMs, the similarity between left and right images of each stereopairs were analyzed. Consequently, the accuracy of the DEM constructed from RED band images of color aerial photograph were proved best.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.3
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• pp.143-151
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• 2009

Forest type map is a main forest thematic map which shows forest type, age class, diameter class and density. This map has been used as a base data in various fields such as forest policy decision-making, land suitability assessment and eco map production etc. But the existing map had many kinds of errors and no metadata because there was no standard for digital map production. On this study, we developed standard for digital forest type map production consisting of 33 unit processes including DB schema design, mapping process, quality control and metadata input process. Based on this standard, country-wide digital forest type map can be produced with consistent quality and standard metadata.