• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2209-2211
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• 1998

This paper presents the matching algorithm with the satellite images using the image warping method. Two stereo images, which are used for the DEM(Digital Elevation Model) extraction, are generally distorted because the images are acquired at different locations and angles. Therefore, the matching Process can't be executed with the original images. To solve this problem, a dynamic triangular image warping method is proposed. At first, the initial matching is executed with seed point, and then, using the matched points from the initial matching, the distorted images is compensated. We experimented this algorithm with the parts of the $6000{\times}6000$ SPOT satellite images. The experiment results show this algorithm is superior to other warping algorithm.

• Imaging Science in Dentistry
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• v.35 no.4
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• pp.207-213
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• 2005

Purpose: To classify and describe the characteristic features of MRI of some ameloblastoma variants. Materials and Methods: The MR images, CT images, and panoramic radiographs in 5 cases were retrospectively examined as follows. First, the contents of ameloblastomas were devided into two portions of either solid or cystic components on the basis of MR signal intensities. The signal intensity within the solid or cystic portions was classified as homogeneous or heterogeneous. Next, the characteristic internal feature of the lesion on T1W1 or T2WI was described. The signal intensities were classified into low, intermediate, slightly high, high, and strong high signal intensity. Results: Unicystic lesion showed homogeneous high signal intensity (SI) on T2W2 and the rim enhancement of the surrounding area including the mural nodule and the thick wall except the central portion on Gd- T1W1. Solid type revealed heterogeneous and high SI area with strong high SI area on T2W2. On Gd- T1W1, the area corresponding to the low signal spot on T1W1 and the strong high signal spot on T2W1 showed low SI. Hybrid type showed slightly enhanced capsular structures and low SI for the round bony septa and the areas connecting the mixed and cystic lesions on T2Wl and Gd-T1W1. Conclusion: MRI could easily assess the relationship between the mixed and cystic findings in ameloblastoma.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3206-3212
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• 2023

We developed a miniaturized multi-dimensional radiation sensor system consisting of an inorganic scintillator array and plastic optical fibers. This system can be applied to remotely obtain the radioactivity distribution and identify the radionuclides in radioactive waste by utilizing a scanning method. Variation in scintillation light was measured in two-dimensional regions of interest and then converted into radioactivity distribution images. Outliers present in the images were removed by using a digital filter to make the hot spot location more accurate and cubic interpolation was applied to make the images smoother and clearer. Next, gamma-ray spectroscopy was performed to identify the radionuclides, and three-dimensional volume scanning was also performed to effectively find the hot spot using the proposed array sensor.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.4
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• pp.177-183
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• 2011

This study intends to investigate patients' exact exposure doses by comparatively measuring ESD (Entrance Surface Dose) with the DAP meter, which excludes scattered rays, and ESD with the Xi multifunction meter, which includes scattered rays, by posture changes for Esophagography test and UGI test. The materialwere examined through Sonialvision-SafireII SPEC overtube system. ESD was measured by using the DAP meter, and as a tool to measure ESD including scattered rays on the plane of incidence of human phantom, the Xi multifunction meter was used. The average fluoroscopic time of Esophagography test was 4.192 minutes and the average number of images was 47.7, while the average fluoroscopic time of UGI test was 6.881 minutes and the average number of images was 37.8. The ratios of the incident dose of DAP meter and the ESD of Xi meter were calculated bydividing the fluoroscopic time and the number of images by each posture change. As for Esophagography test, the dose increased by 21.6~55.5% in the fluoroscopic test and by 4.8~24.7% in the spot test. In the front spot test, however, the does increased by as little as 5.3%. As for UGI test, the dose increased by 21.1~49.5% in the fluoroscopic test and by 10.1~34.9% in the spot test. It is expected that measuring doses in consideration of scattered rays by posture changes will be an important index in evaluating and managing patients' exact exposure doses for each test above. Furthermore, it is judged that this sort of study is inevitable and desirable to reduce patients' exposure doses after all.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.134-142
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• 2005

In building geographic information for North Korea, we proposed the method of using SPOT-5 image, designed geographic information layers, and inspected the location accuracy. Basically this study is similar to existing method in which uses GCPs to build geographic information from SPOT-5 satellite imagery. However, this study adopted a different method of GCP acquisition. The GCP used in this study is a triangulation point which was made at Japanese imperialism eras. The location accuracy error was 8.755 meters horizontally, which satisfied the tolerance of 17.5 meters in the 1:25,000 scale public survey guidance. In conclusion, we suggest that geographic information for North Korea can be built from SPOT-5 images with the triangulation point made in Japanese imperialism times.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.529-534
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• 2009

In this study, we investigate the feasibility of modeling entire image strips that has been acquired from the same orbital segments. We tested sensor models based on satellite orbit and attitude with different sets(Type1 ~ Type4) of unknowns. We checked the accuracy of orbit modeling by establishing sensor models of one scene using control points extracted from the scene and by applying the models to adjacent scenes within the same orbital segments. Results indicated that modeling of individual scenes with 1st or 2nd order unknowns was recommended. We tested the accuracy of around control points, digital map using the HIST-DPW (Hanjin Information Systems & Telecommunication Digital Photogrammetric Workstation) As a result, we showed that the orbit-based sensor model is a suitable sensor model for making 1/25,000 digital map.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.1
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• pp.61-69
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• 2003

There is various kinds cause that influence to created DEM and orthoimage using stereo satellite images. Specialty, research about effect that GCP number gives to accuracy of DEM, orthoimage and modeling may have to be gone ahead. Therefore, this research increases GCP number by 5 to 30 and created each modeling, DEM and orthoimage using SPOT panchromatic images that resolution is 10m by digital image processing method. Accuracy assessment did by orthoimage using 20 check point. As a result, GCP number between 10∼30 modeling RMSE is 1 pixel low appear. Horizontal·vertical error that use orthoimage looked tendency that decrease GCP number increases, and confirmed by the most economical in GCP number 10∼15. Also, analyze correlation of GCP number and orthoimage position accuracy and presented improvement plan and research task hereafter.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.1
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• pp.147-155
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• 2015

The existing field survey and aerial photography involve the waste of manpower and economic loss in the coastline survey. To minimize these disadvantages, the digitization for efficient coastline extraction was conducted in this study using the points extracted from the standard coastline of the approximate highest high water and the diverse satellite images (KOMPSAT-3, SPOT-5, Landsat-8 and Quickbird-2), and the comparative accuracy analysis was conducted. The differences between the standard coastline points of the approximate highest high water and the coastline of each satellite were smallest for KOMPSAT-3, followed by Quickbird-2, SPOT-5 and Landsat-8. The significant probability from between the multipurpose applications satellite and Quickbird-2 (significant probability two-tailed) was statistically significant at 1% significance level. Therefore, high-resolution satellite images are required to efficiently extract the coastline, and KOMPSAT-3, from which images are easily acquired at a low cost, will enable the most efficient coastline extraction without external support.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.331-341
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• 1998

With high resolution capability, satellite images are expanding their roles from earth resource monitorings to map production. Until now, maps are produced from airborne photos, but as large as at 1:2,400 scale, low cost satellite ortho images will replace the airborne photos. However, there has been no standard for map productions with satellite images. In this paper, we study the process of map productions with the satellite images of SPOT, IRS-lC, KOMPSAT, the positional accuracy of map features extracted from the satellite images, and the relationship between the image resolution and the map scale.

• Laser Solutions
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• v.7 no.2
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• pp.11-18
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• 2004

We propose a novel application of optical coherence tomography (OCT) to monitor pit formation in laser irradiated optical storage materials. A multilayer optical storage recordable compact disk, is composed of multiple layers, each of different structure. Disks were irradiated with aQ-Switched Nd:YAG laser with an energy of 373 mJ. Post-irradiated disks were evaluated by OCT and those images were compared with optical microscopy. Our results indicate that OCT is a useful instrument to investigate pit formation in multilayer optical storage disks and might also provide information to optimize optical memory technology.