• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4D
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• pp.579-586
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• 2008

In this study, it was evaluated that the 3D tracking accuracy of basketball zone track line by real time GNSS satellite positioning methods which are VRS (Virtual Reference System), DGPS (Marine Differential GPS) and PP (Point Positioning) methods. The results of comparison between three methods over horizontal track of basketball zone, VRS, DGPS and PP methods showed ${\pm}$ several cm, ${\pm}$ m, and ${\pm}$ 2m horizontal position accuracy compared with real size respectively. And also, the grade and height deviation of the checking points on basketball zone by VRS method is very similar to the real grade and height, but results by DGPS and PP methods showed big variation and deviation in each case. We expected that VRS method using GNSS reference network will be a very useful tool compared with single based RTK method in real time accurate positioning such as precision construction fields, especially.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.201-208
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• 2011

With the increase in the number of smartphone users, precise 3D positional information is required by various applications. The positioning accuracy using civilian single-frequency pseudoranges is at the level of 10 m or so, but most applications these days are asking for a sub-meter level Therefore, instead of an absolute positioning technique, the VRS-based differential approach is applied along with the correction of the double-differenced (DD) residual errors using FKP (Flachen-Korrektur-Parameter). The VRS (Virual Reference Station) is located close to the rover, and the measurements are generated by correcting the geometrical distance to those of the master reference station. Since the unmodeled errors are generally proportional to the length of the baselines, the correction parameters are estimated by fitting a plane to the DD pseudorange errors of the CORS network. The DD positioning accuracy using 24 hours of C/A code measurements provides the RMS errors of 37 cm, 28 cm for latitudinal and longitudinal direction, respectively, and 76 cm for height. The accuracy of the horizontal components is within ${\pm}0.5m$ for about 90% of total epochs, and in particular the biases are significantly decreased to the level of 2-3 cm due to the network-based error modeling. Consequently, it is possible to consistently achieve a sub-meter level accuracy from the single-frequency pseudoranges using the VRS and double-differenced error modeling.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.211-221
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• 2012

To utilize omni-directional images acquired by a rotating line camera for indoor spatial information services, we should register precisely the images with respect to an indoor coordinate system. In this study, we thus develop a georeferencing method to estimate the exterior orientation parameters of an omni-directional image - the position and attitude of the camera at the acquisition time. First, we derive the collinearity equations for the omni-directional image by geometrically modeling the rotating line camera. We then estimate the exterior orientation parameters using the collinearity equations with indoor control points. The experimental results from the application to real data indicate that the exterior orientation parameters is estimated with the precision of 1.4 mm and $0.05^{\circ}$ for the position and attitude, respectively. The residuals are within 3 and 10 pixels in horizontal and vertical directions, respectively. Particularly, the residuals in the vertical direction retain systematic errors mainly due to the lens distortion, which should be eliminated through a camera calibration process. Using omni-directional images georeferenced precisely with the proposed method, we can generate high resolution indoor 3D models and sophisticated augmented reality services based on the models.

• Korean Institute of Interior Design Journal
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• v.13 no.1
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• pp.3-10
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• 2004

The subject on presentation technique is the class which helps to develop the capability of sensual and creative acts to the students who major in interior design. It helps to understand plasticity and space through the theory of the light and the object, and to develop the capability which realizes one's idea to the actual and visual formations. It also enable the students to explain their designs to the customers by studying the technique which transfers 2D diagram to 3D presentation. Because of these objectives of the class, the departments which major in interior design in Korea consider the class on presentation technique as one of the mun subjects in basic curriculum. However, most of the textbooks related to the presentation technique published in Korea are in the lack of original characteristics for the field of domestic interior design since they refer to or employ the contents of architectural field by directly translating foreign articles. In addition, most of the classes on the presentation technique are taught not by professors but by lecturers so that the class objectives may be varied by their standards for the class. Therefore, it is not easy for each department to set up the one's own characteristics in the field of presentation technique. This study is to analyze the problems in the subjects of presentation technique by investigating the current situations for the subjects on presentation technique in domestic colleges and by surveying the personnels engaged in the field of domestic interior design. Also, the study has the objective to propose the development plan of educational program for the presentation technique in order to enable the student to effectively work in real business.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.127-137
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• 2018

Recently, UAVs and Drones have been used for various applications. In particular, in the field of surveying, there are studies on the technology for monitoring the terrain based on the high resolution image data obtained by using the UAV-equipped digital camera or various sensors, or for generating high resolution orthoimage, DSM, and DEM. In this study, we analyzed the accuracy of GCP(Ground control point) matching using UAV and VRS-GPS. First, we used VRS-GPS to pre-empt the ground reference point, and then imaged at a base altitude of 150m using UAV. To obtain DSM and orthographic images of 646 images, RMSE was analyzed using pix4d mapper version As a result, even if the number of GCP matches is more than five, the error range of the national basic map(scale : 1/5,000) production work regulations is observed, and it is judged that the digital map revision and gauging work can be utilized sufficiently.

• Journal of Fashion Business
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• v.1 no.1
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• pp.99-109
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• 1997

The purpose of this study is to survey the conditions of women's wears manufacturing industries and finds out their qualitative problems and suggests the solutions to help women's wears manufacturing industries adapting themselves well to the fashion industries which is being individualized, high profiled and differentiated and thus helpes them to produce the competitive commodities through high-qualities and technological improvements. For this purpose, I had sampled the factories which located in Seoul and Kyunggido areas and produced women's apparels for domestic consumers. The questionnaires for this survey were designed by interviewing the representatives of 31 women's wears manufacturing industries, while the collected data were processed using the SAS statistical program for frequency, percentage, chi-square test, t-test. The results of the survey can be summarized as follows; 1. It was found that women's wears manufacturing industries were getting smaller scale or pettier in terms of capital, number of employees or scale of factory. 2. The number of the employees is getting decrease every year, which is posed as most serious problems of the surveyed manufacturer. Such a decrease of employees may be attributable to the fact that women's wears manufacturing industries are regarded as one of 3D businesses and therefore the employees leave their workspaces for more rewarding service industries. 3. It was found that women's wears manufacturing industries relied on more recontracts than self-productions. In 1995, 83.7% of their productions were out of recontracts, and this rate is getting increase. 4. 51.6% of the surveyed manufacturer operate by straight line system or other types of line system, while 48.4% of the remaining managed a pair system. 5. As a result of surveying the perspective of women's wears manufacturing industries into the 21 st century is as followed. 41.9% of them were optimistic, and 25.8% were pessimistic about their futures.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.751-756
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• 2002

Since the operation of the first satellite-based navigation services, satellite positioning has played an increasing role in both surveying and navigation, and has become an indispensable tool for precise relative positioning. However, in some situations, e.g. at a low angle of elevation, the use of satellites for navigation is seriously restricted because obstacles like buildings and mountains can block signals. As a mean to resolve this problem, the quasi-zenith satellite system has been proposed as a next-generation satellite navigation system. Quasi-zenith satellite is a system which simultaneously deploys several satellites in a quasi-zenith geostationary orbit so that one of the satellites always stay close to the zenith if viewed from a specific point on the ground of East Asia. Thus, if a position measurement function compatible with GPS is installed in the quasi-zenith and stationary satellites, and these satellites are utilized together with the GPS, four satellites can be accessed simultaneously nearly all day long and a substantial improvement in position measurement, especially in metropolitan areas, can be achieved. The purpose of this paper is to evaluate the effectiveness of quasi-zenith satellite system on positioning accuracy improvement through simulation by using precise orbital information of the satellites and a three-Dimensional digital map. Through this simulation system, it is possible to calculate the number of simultaneously visible satellites and available area of the positioning without the need of actual observation.

• Korean Journal of Remote Sensing
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• v.24 no.2
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• pp.205-211
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• 2008

The river management in Korea had been focused on line based 2D spatial data for the developing river management application system. In this study, the polygon based 3D spatial data such as aerial photos and satellite images were selected and used through comparing their resolution levels for the river environment management. In addition, 1m detailed DEM (Digital Elevation Model) was constructed to implement the real topography information around river so that the damage area scale could be extracted for flood disaster. Also, the social environment thematic maps such as a cadastral map or land cover map could be used to verify the real damage area scale by overlay analysis on aerial photos or satellite images. The construction of these spatial data makes possible to present the real surface information and extract quantitative analysis to support the scientific decision making for establishing the river management policy. For the further study, the lidar surveying data will be considered as the very useful data by offering the real height information of riverbed as the depth of river so that flood simulation can give more reality.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.3
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• pp.31-54
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• 2019

The purpose of this study is to present the basic data for establishing the management plan of forest ecosystem in Honam-Jeongmeak and Geumnamhonam-Jeongmaek by surveying and analysing the vascular plants distributed in Jangansan(A-site), Palgongsan(B-site), Mandeoksan(C-site), Chuwolsan (D-site), Cheonunsan(E-site) and Jeamsan(F-site). The numbers of flora were 813 taxa including 115 families, 406 genera, 700 species, 4 subspecies, 94 varieties and 15 forms. There were 500 taxa in A-site, 427 taxa in B-site, 402 taxa in C-site, 449 taxa in D-site, 345 taxa in E-site and 524 taxa in F-site. The rare plants were 12 taxa including Paeonia japonica, Iris minutoaurea, Chloranthus fortunei and so forth. In IUCN Red List categories, there were 1 taxon of EN, 2 taxa of VU, 8 taxa of LC and 1 taxon of DD. The Korean endemic plants were 20 taxa including Salix koriyanagi, Thalictrum actaefolium var. brevistylum, Saussurea pseudogracilis and so forth. The specific plants by floristic region were 108 taxa including 58 taxa of grade I, 30 taxa of grade II, 16 taxa of grade III, 2 taxa of grade IV and grade V, respectively. The plants adaptable to climate change were 18 taxa including 11 taxa of southern plant and 7 taxa of northern plants. The naturalized plants were 49 taxa including Rumex nipponicus, Brassica juncea, Trifolium repens and so forth. The invasive alien plants were 4 taxa including Rumex acetocella, Solanum carolinense, Ambrosia artemisiifolia and Aster pilosus.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.697-703
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• 2023

Intertidal zones, akin to tidal flats, are among the potential areas where underwater cultural heritage might be submerged. However, the shallow depths in these regions present challenges for conventional vessel-based survey methods. Moreover, during low tides, intertidal zones transform into tidal flats, limiting the efficiency of survey efforts due to restricted access and potential risks. As a result, proper underwater cultural heritage surveys encounter difficulties in these environments. In recent times, extensive research is underway to address these issues by investigating underwater cultural heritage surveys in intertidal zones, encompassing diverse fields, including equipment-based investigations. This study aimed to explore the feasibility of utilizing unmanned aerial vehicles (UAVs) to conduct intertidal cultural heritage surveys, employing aerial photography and 3D mapping to create detailed orthoimages and 3D models. The study focused on assessing the potential application of these techniques for cultural heritage surveying within intertidal zones. Notably, the survey conducted in Jindo's Naesan-ri demonstrated high-resolution capabilities, enabling the distinction of actual pottery fragments mixed within gravel fields. Similarly, in the survey of Jindo's Byeokpa-hang, it was found that a wooden pillar structure existed in a section about 200m long. The integration of various sensors, including LiDAR, with UAVs allows for diverse investigation possibilities, including bathymetric measurements, and is expected to facilitate the acquisition of varied datasets for further research and assessment.