• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.28 no.4
• /
• pp.449-454
• /
• 2010

Lately, airborne digital camera and airborne laser scanner in field of airborne surveying are used to build geography information such as digital ortho photo map and DEM(Digital Elevation Model). In this study, 3D position accuracy is compared medium format CCD camera RCD105 with airborne digital camera DMC. For this, test area was decided for aerial photograph. And using 1/1,000 scale digital map, ground control points were selected for aerial triangulation and check points were selected for horizontal/vertical accuracy analysis using softcopy stereoplotter. Accuracy of RCD105 and DMC was estimated by result of aerial triangulation and result of check points measurement of using softcopy stereoplotter. In result of aerial triangulation, RMSE(Root Mean Square Error) X, Y, Z of RCD105 is 2.1, 2.2, 1.3 times larger than DMC. In result of check point measurement using softcopy stereoplotter, horizontal/ vertical RMSE of RCD105 is 2.5, 4.3 times larger than DMC. Even though accuracy of RCD105 is lower than DMC, it is maybe possible to make digital map and ortho photo using RCD105.

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

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2007.04a
• /
• pp.295-299
• /
• 2007

Today, ubiquitous technology (e.g. computers or networked devices pervade everywhere we are) has enlarged by great advancement of information and communication technologies. If ubiquitous technologies is applied to, innovation of spatial information technology is expected. traditional spatial information technologies such as survey, GIS, GPS, LBS, and RS and ubiquitous technology gradual1y have been converged. The aim of this study is to create shared visions in spatial information technologies by scenario based roadmapping. So, we surveyed the state of the art in main spatial information technologies, market status and patent map. Consequently, prospects of spatial information technologies is suggested. The aim of 1st and 2nd NGIS project focused on map supplier was to develop digital map(e.g. framework data, various thematic map). As a result, the best technology of digital mapping is achieved in the world. But, there is not enough to develop GIS and LBS solution. Current market in GIS S/W and Telematics is about 384billon won and 250billion won. a patent is applied in the order, like a USA(1571case, 47%), Japan(883case, 26%), EU(478case, 14%), Korea(446case, 13%). In the future, spatial information technology fused on ubiquitous technology will be focused on user's demand and developing convenience context. The developing target will be realtime monitoring of 3D spatial data based on high resolution coordinate system, sharing and supplying multi-sensor data considered users demand, location service by ubiquitous technologies.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.3
• /
• pp.562-568
• /
• 2014

With the development of computer technology, augmented reality (Augmented Reality, AR) technology in the future, one of the main directions of development of human interface technology is emerging. On augmented reality based on the design and implementation of a digital business card system. In this paper, a Smartphone is simply information through recognizable digital business card contains information about the system. Digital business card system is compared to the way existing hardware in a way visually-based high precision. In addition, registered as a 3D computer vision of augmented reality technology skills and real-world situations convergence technology for research. Future research, 3D electronic map for Smartphone apps as of the application user interface on the side for research is needed.

• The Journal of Advanced Prosthodontics
• /
• v.7 no.6
• /
• pp.460-467
• /
• 2015

PURPOSE. The aim of this study is to evaluate the appropriate impression technique by analyzing the superimposition of 3D digital model for evaluating accuracy of conventional impression technique and digital impression. MATERIALS AND METHODS. Twenty-four patients who had no periodontitis or temporomandibular joint disease were selected for analysis. As a reference model, digital impressions with a digital impression system were performed. As a test models, for conventional impression dual-arch and full-arch, impression techniques utilizing addition type polyvinylsiloxane for fabrication of cast were applied. 3D laser scanner is used for scanning the cast. Each 3 pairs for 25 STL datasets were imported into the inspection software. The three-dimensional differences were illustrated in a color-coded map. For three-dimensional quantitative analysis, 4 specified contact locations(buccal and lingual cusps of second premolar and molar) were established. For two-dimensional quantitative analysis, the sectioning from buccal cusp to lingual cusp of second premolar and molar were acquired depending on the tooth axis. RESULTS. In color-coded map, the biggest difference between intraoral scanning and dual-arch impression was seen (P<.05). In three-dimensional analysis, the biggest difference was seen between intraoral scanning and dual-arch impression and the smallest difference was seen between dual-arch and full-arch impression. CONCLUSION. The two- and three-dimensional deviations between intraoral scanner and dual-arch impression was bigger than full-arch and dual-arch impression (P<.05). The second premolar showed significantly bigger three-dimensional deviations than the second molar in the three-dimensional deviations (P>.05).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.25 no.5
• /
• pp.475-482
• /
• 2007

Most golfers believe that knowing yardages will improve their score. Certainly it helps with club selection. But, simple "Graphic" yardage guides being notorious for error and inaccuracies, which a serious golfer will pick immediately, only serve to erode the players enjoyment and ultimately, golf course satisfaction. Someone believes with low-level aerial photographic images, golfer will be impressed with the accuracy of the depiction, helping them play a more confident game. But, there are no mapping products in true 3-D available in the world that allows a golfer to determine shot distances in yards or meters. So, we suggest an lenticular technology for real 3-D display as a viable alternative to conventional image map solution. This technology is an image display method for the generation of multi-image effects like 3D visualization or animation. This methodology is cutting edge stereoscopic image which overcomes the limitation of conventional photo tech by recomposing and producing 3 dimensional images. A significant strength of this methods its versatility concerning display effects. The main use of the hardcopy 3-D lenticular displays is in the fields of science, education, planning, and representation. This paper gives a concise overview of the lenticular foil technology and describes the production of the true 3-D yardage book of golf courses. For this study, 3-D effects are achieved and evaluated with the lenticular display by incorporation multiple synthetic images based on digital topographic terrain model and by using the two images of the actual stereopair.

• Korean Journal of Remote Sensing
• /
• v.9 no.2
• /
• pp.21-34
• /
• 1993

Digitalized topographic information is necessary for many areas such as landscape analysis, civil engineering planning and design, and geographic information systems. It can also be used in flight simulator and automatic navigation of unmanned plane if it is stored in computer in relevant format. Topographic information is coded with various symbols including contour lines, and is analyzed by trained personnels. The information should be stored in computer for automatic analysis, but it requires a lot of time and manpower to enter the contours using manual input devices such as digitizing tablet. This paper deals with automatic extraction and reconstruction of 3D topographic information from 2D terrain map. Several algorithms were developed in this work including contour segment finding algorithm and contour segment linking algorithm. The algorithm were tested using real 2D terrain map.

• The Journal of Korean Academy of Prosthodontics
• /
• v.58 no.1
• /
• pp.7-13
• /
• 2020

Purpose: This study was to evaluate marginal and internal discrepancy of 3-unit fixed dental prostheses (FDP) fabricated by subtractive manufacturing and additive manufacturing. Materials and methods: 3-unit bridge abutments without the maxillary left second premolar were prepared (reference model) and the reference model scan data was obtained using an intraoral scanner. 3-unit fixed dental prostheses were fabricated in the following three ways: Milled 3-unit FDP (MIL), digital light processing (DLP) 3D printed 3-unit FDP (D3P), stereolithography apparatus (SLA) 3D printed 3-unit FDP (S3P). To evaluate the marginal/internal discrepancy and precision of the prosthesis, scan data were superimposed by the triple-scan protocol and the combinations calculator, respectively. Quantitative and qualitative analysis was performed using root mean square (RMS) value and color difference map in 3D analysis program (Geomagic control X). Statistical analysis was performed using the Kruskal-Wallis test (α=.05), MannWhitney U test and Bonferroni correction (α=.05/3=.017). Results: The marginal discrepancy of S3P group was superior to MIL and D3P groups, and MIL and D3P groups were similar. The D3P and S3P groups showed better internal discrepancy than the MIL group, and there was no significant difference between the D3P and S3P groups. The precision was excellent in the order of MIL, S3P, and D3P groups. Conclusion: Within the limitation of this study, the 3-unit fixed dental prostheses fabricated by additive manufacturing showed better marginal and internal discrepancy than the those of fabricated by subtractive manufacturing, but the precision was poor.

• Journal of Urban Science
• /
• v.7 no.1
• /
• pp.29-38
• /
• 2018

The cadastral rehabilitation project, which has been implemented since 2012, is a project to re-examine the national land that is not in conformity with the cadastral map, There is a lot of trouble in securing financial resources for business execution. This study examines the utility of UAS(Unmanned Aerial System) image - based cadastral demarcation as an alternative to budget reduction in the current state of cadastral rehabilitation, reasonable boundary adjustment, UAV(Unmanned Aerial Vehicles) is used to create 3D models and orthoimages of business districts, and to check accuracy by superimposing and comparing with digital maps of NGII(National Geographic Information Institute). As a result of the study, the accuracy of the 3D model and the orthoimage through the SfM(Structure-from-Motion) - based image interpretation of the digital map of the NGII were derived. In particular, we confirmed the similarity of UAS-based orthoimage with the cadastral boundaries affirmation, It is anticipated that the cost saving effect of current survey and boundary survey can be expected. In addition, it is easy to prepare a report to reduce civil complaints, which is a problematic element of the adjustment.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.11 no.1
• /
• pp.105-115
• /
• 2008

In this study, we wished to forecast the damage district by tsunami's occurrence. For this, we analyzed tsunami that can happen in our country's neighborhood coast using past data, and established tsunami's scenario by imagination with analysis result. we created a 3D topographical model about study area and analyzed an inundation area by achieving simulation by scenario. Also, we produced an imaginary inundation map by overlaying the simulation results on digital map. This study result might be utilized as infra-technology for operation of tsunami's forecast/alarm system and establishment of disaster prevention policy.