• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.79-85
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• 2008

This study aims to derive a practical coordinate transformation method for the existing geographic information database. After analyzing the status and problems of existing 1/1,000 digital base map and GIS application database, the transformation parameters are estimated and the accuracy of the transformation is determined based on the transformed coordinates. We analyzed the accuracy of a transformation using the published national transformation coefficients as well as the estimated local transformation coefficients using national and urban control points in a study area. In addition, the 1/1,000 digital base map from aerial triangulation is compared with respect to the coordinates of urban control points. Based on the comparison, the biases on the national control points which were used at the time of digital map generation was analyzed. Then, the accuracy of transformed coordinates based on the world geodetic system using local transformation coefficients estimated from urban control points are determined. We also analyzed the transformation accuracy of underground infrastructure database using the same transformation method as the case of 1/1,000 digital base map. Through this study, it was found that the estimation of transformation coefficients by Molodensky-Badekas using urban control points was suitable for a local government. Furthermore, it was obvious that the accuracy of a 2-dimensional affine transformation was comparable to that of 7 parameter transformation for a local area. Applying the coordinate transformation and bias correction, we could transform GIS application database which was built by an offset surveying based on digital base map within the transformation accuracy of 10 cm. Therefore, it was judged that there will not be a big problem on the transformation of the GIS DB to the world geodetic system.

• School Mathematics
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• v.16 no.4
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• pp.677-690
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• 2014

The main goals of learning geometry include developing spatial ability and concepts on geometric objects based on understanding the attributes and relationships of them. While the instructions on geometric objects follow the concept development models, the ones on spatial ability are designed from the perspective of geometric transformation. However, there is a need for instructional materials to emphasizing the relationships among geometric concepts. This study hypothesizes that spatial ability stems from the intuitive understanding of geometric objects and the relational understanding on concepts, and it considers the isoperimetric problems as instructional materials to foster spatial ability.

• Korean Institute of Interior Design Journal
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• no.18
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• pp.96-102
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• 1999

This study is about the spatial organization of Korean houses designed by architects. It is focused on the characteristics and transformation of spatial organization of houses designed since 1970. The variety and regularity of organization existed at the spatial structure of Korean houses are analysed through typological theory. In this study, the connecting methods between rooms appeared in the plans of 190 detached houses are analysed and classified chronologically. The connecting methods of space between L-D-K, between living room and master bedroom are analysed. And the methods of spatial division inside of master bedroom are also analysed. As a result of the analyses, it is clear that the spatial organization of architects' houses turns its direction from the concept of 'unifying and clustering' to that of 'dividing and segregating' . In contrast to the 70s, there shows a strong diversity in the connecting methods after the 80s with adaptation of the 'language of linear plan' using many forms of intermediary elements between spaces. This result would be relative to the changing trend of design philosophy and the changing tendency in the relationship between the inside and outside space of house.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.351-353
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• 2006

• Journal of the Korean housing association
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• v.26 no.2
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• pp.1-12
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• 2015

The era of globalization has ushered in dramatic changes in the past decade covering a wide range of distinct political, economic and cultural trends whereby people adapt their houses to suit their needs and desires. This paper discusses the process of change analytically, emphasizing the importance of understanding the transformation of Lao traditional houses and its impact factors to the transformation and adaptation to suit with globalization trend, and conservation of the characteristics of traditional houses. This study takes place in Luangprabang, an ancient city of Lao PDR, which was designated as a world heritage city in 1995 as it is rich with diverse, tangible and intangible values. Five cases of traditional house in Luangprabang are examined to understand their transformation through time, by analyzing the basic spatial formation, components and elements, especially to find out the impact factors to such transformation. The study revealed that the transformation of the traditional house is subject to not just one single factor, but to a number of factors, where globalization, regulation, economy, and social aspect factors play a prime role and are the root for all these changes. The case study also indicates that these changes are connected to the benefits of income generation as a survival strategy for the low and middle-income people in Luangprabang as well as the housing demands. In the transition period a new residential type appeared accordingly, in which living spaces were categorized according to their general functions. There was a harmony between people's needs and the physical characteristics of the house.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.195-202
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• 2021

In this study, from a long-term perspective, we tried to find and present a plan to apply the results of transformation of cadastral coordinates to the world geodetic system in stages for cadastral records of graphical and digital cadastral area. There was a case where the difference in area before and after the transformation occurred irregularly in the transformation result of the cadastral coordinate system currently being promoted. In addition, it was found that transformation errors in cadastral non-coincidence areas occurred accumulatively, and the period for acquiring world geodetic results for cadastral reference points was insufficient. In order to solve this problem, the study proposed a plan to provide spatial information and related fields through advancement of continuous cadastral maps, etc. for maps that have been primarily transformed by the end of 2020. In addition, the maps used for cadastral surveying purposes were presented in the direction of applying them to cadastral records in numerical form in the long term to conform to the characteristics of graphical and digital cadastral area. It is expected that more stable cadastral record will be reflected by applying the world coordinate transformation performance by dividing the graphical and digital cadastral area.

• Journal of Cadastre & Land InformatiX
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• v.45 no.2
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• pp.101-116
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• 2015

In Boundary Point Coordinate Register Area, the accuracy on Transformation of World Geodetic System(WGS) is determined by surveying results at the reference point. However, the present surveying result in reference points indicates the irregular performance due to the limitations of measurement techniques and methodologies, moreover, can be contaminated by various error sources from the unique characteristics of each project district and start time of the project. Therefore, the main purpose of present investigation is to conduct an inquest into error cause by project districts for each type in Boundary Point Coordinate Register Area, and propose the improvement plan of surveying accuracy through the WGS Transformation and verification-surveying.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.295-302
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• 2022

Sparse-view computed tomography (CT) imaging technique is able to reduce radiation dose, ensure the uniformity of image characteristics among projections and suppress noise. However, the reconstructed images obtained by the sparse-view CT imaging technique suffer from severe artifacts, resulting in the distortion of image quality and internal structures. In this study, we proposed a convolutional neural network (CNN) with wavelet transformation and residual learning for reducing artifacts in sparse-view CT image, and the performance of the trained model was quantitatively analyzed. The CNN consisted of wavelet transformation, convolutional and inverse wavelet transformation layers, and input and output images were configured as sparse-view CT images and residual images, respectively. For training the CNN, the loss function was calculated by using mean squared error (MSE), and the Adam function was used as an optimizer. Result images were obtained by subtracting the residual images, which were predicted by the trained model, from sparse-view CT images. The quantitative accuracy of the result images were measured in terms of peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). The results showed that the trained model is able to improve the spatial resolution of the result images as well as reduce artifacts in sparse-view CT images effectively. Also, the trained model increased the PSNR and SSIM by 8.18% and 19.71% in comparison to the imaging model trained without wavelet transformation and residual learning, respectively. Therefore, the imaging model proposed in this study can restore the image quality of sparse-view CT image by reducing artifacts, improving spatial resolution and quantitative accuracy.

• Spatial Information Research
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• v.12 no.2
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• pp.151-163
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• 2004

This study aims to develop a standard protocol by which users can exchange data information efficiently between KOSDIC and GIS. The ultimate goal from this study is to propose a data exchange format using KOSIC. The background of this study is that GIS industry sector is vigorously developing linked to spatial information construction such as UIS, LIS, EIS, AM/FM through supporting by regional government institution. According to do, the format of data transformation becomes major issue. GIS data can easily transfer to CAD version but when CAD data convert to GIS format (DWG->DXF->SHP) cannot get high success rate due to errors and problems. In addition, CAD data feature is made from oriental structure which is made of point and line faeture so that GIS system is impossible to data transformation. In the reason, the biggest problem is discordance of symbolization in integration and standard of data format. By investigation the usability of this study, conclusion are drawn efficient alternative plan in data transformation. Though this wort we will be able to provide a better transformation of data conversion between CAD format and GIS format. Accordingly, it is of important to enrich the integrated construction information infrastructure, which accommodates ever-changing constructions environment.

• Spatial Information Research
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• v.11 no.4
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• pp.421-437
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• 2003

In order to calculate the position of parcel boundary points, the area of the Parcel, and the length of the parcel boundary lines using a digitalized cadastral map or maps, the distortion of the map has to be corrected. The correction methods, such as the method of 2D affine transformation using 4 comer points of the edge lines, the method of tessellation into 9 subregions, the method of using the original surveying sheets, and the method of straightening the 4 edge lines, have been developed. In this Paper, the four methods were programed and applied to some sample cadastral maps and the correction accuracies were obtained and analysed. No method could prefectly correct the distortions because the distortions were irregular throughout the maps. However, it is found that tile method of straightening the 4 edge lines is the one which can minimize the distortions when the method is applied after applying the 2D projective transformation on the maps using the 4 comer points of the edges.