• Title/Summary/Keyword: Target Period for Reconstruction

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A Study on the Landscape Elements and Construction of Eupseong (county seat) in the Late Joseon Dynasty (조선후기 읍성 취락의 경관 요소와 경관 구성 - 태안읍성, 서산읍성, 해미읍성을 중심으로 -)

  • Jeon, Jong-Han
    • Journal of the Korean association of regional geographers
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    • v.21 no.2
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    • pp.319-341
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    • 2015
  • Eupseong (county seat) represents the Korean historic city which had constructed intentionally by central government during Joseon Dynasty. There were variety of government or county offices which named as Gaeksa, Dongheon, Nea, Jilcheong, and so on. Also, there are houses of the people in many Eupseong but not all of them. This study aims to reconstruct the landscape elements and its overall construction of Eupseong in the Late Joseon dynasty on the original land registration map(1913). For this purpose, the author underlines to set-up target period for reconstruction. This study considers the early 19th century in Joseon as completion period of Eupseong landscape, and then researches distribution of Eupseong and major elements of its landscape in national scale. Based on those results, the author tries to reconstruct location of major landscape elements and layout of Eupseong landscape in the early 19th century on the original land registration map in case of Taean Eupseong, Seosan Eupseong, and Haemi Eupseong in Chungcheongnam-do (province), Korea.

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Development of underwater 3D shape measurement system with improved radiation tolerance

  • Kim, Taewon;Choi, Youngsoo;Ko, Yun-ho
    • Nuclear Engineering and Technology
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    • v.53 no.4
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    • pp.1189-1198
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    • 2021
  • When performing remote tasks using robots in nuclear power plants, a 3D shape measurement system is advantageous in improving the efficiency of remote operations by easily identifying the current state of the target object for example, size, shape, and distance information. Nuclear power plants have high-radiation and underwater environments therefore the electronic parts that comprise 3D shape measurement systems are prone to degradation and thus cannot be used for a long period of time. Also, given the refraction caused by a medium change in the underwater environment, optical design constraints and calibration methods for them are required. The present study proposed a method for developing an underwater 3D shape measurement system with improved radiation tolerance, which is composed of commercial electric parts and a stereo camera while being capable of easily and readily correcting underwater refraction. In an effort to improve its radiation tolerance, the number of parts that are exposed to a radiation environment was minimized to include only necessary components, such as a line beam laser, a motor to rotate the line beam laser, and a stereo camera. Given that a signal processing circuit and control circuit of the camera is susceptible to radiation, an image sensor and lens of the camera were separated from its main body to improve radiation tolerance. The prototype developed in the present study was made of commercial electric parts, and thus it was possible to improve the overall radiation tolerance at a relatively low cost. Also, it was easy to manufacture because there are few constraints for optical design.

A Theoretical Model for the Analysis of Residual Motion Artifacts in 4D CT Scans (이론적 모델을 이용한 4DCT에서의 Motion Artifact 분석)

  • Kim, Tae-Ho;Yoon, Jai-Woong;Kang, Seong-Hee;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.23 no.3
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    • pp.145-153
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    • 2012
  • In this study, we quantify the residual motion artifact in 4D-CT scan using the dynamic lung phantom which could simulate respiratory target motion and suggest a simple one-dimension theoretical model to explain and characterize the source of motion artifacts in 4DCT scanning. We set-up regular 1D sine motion and adjusted three level of amplitude (10, 20, 30 mm) with fixed period (4s). The 4DCT scans are acquired in helical mode and phase information provided by the belt type respiratory monitoring system. The images were sorted into ten phase bins ranging from 0% to 90%. The reconstructed images were subsequently imported into the Treatment Planning System (CorePLAN, SC&J) for target delineation using a fixed contour window and dimensions of the three targets are measured along the direction of motion. Target dimension of each phase image have same changing trend. The error is minimum at 50% phase in all case (10, 20, 30 mm) and we found that ${\Delta}S$ (target dimension change) of 10, 20 and 30 mm amplitude were 0 (0%), 0.1 (5%), 0.1 (5%) cm respectively compare to the static image of target diameter (2 cm). while the error is maximum at 30% and 80% phase ${\Delta}S$ of 10, 20 and 30 mm amplitude were 0.2 (10%), 0.7 (35%), 0.9 (45%) cm respectively. Based on these result, we try to analysis the residual motion artifact in 4D-CT scan using a simple one-dimension theoretical model and also we developed a simulation program. Our results explain the effect of residual motion on each phase target displacement and also shown that residual motion artifact was affected that the target velocity at each phase. In this study, we focus on provides a more intuitive understanding about the residual motion artifact and try to explain the relationship motion parameters of the scanner, treatment couch and tumor. In conclusion, our results could help to decide the appropriate reconstruction phase and CT parameters which reduce the residual motion artifact in 4DCT.

The Precise Three Dimensional Phenomenon Modeling of the Cultural Heritage based on UAS Imagery (UAS 영상기반 문화유산물의 정밀 3차원 현상 모델링)

  • Lee, Yong-Chang;Kang, Joon-Oh
    • Journal of Cadastre & Land InformatiX
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    • v.49 no.1
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    • pp.85-101
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    • 2019
  • Recently, thank to the popularization of light-weight drone through the significant developments in computer technologies as well as the advanced automated procedures in photogrammetry, Unmanned Aircraft Systems have led to a growing interest in industry as a whole. Documentation, maintenance, and restoration projects of large scaled cultural property would required accurate 3D phenomenon modeling and efficient visual inspection methods. The object of this study verify on the accuracies achieved of 3D phenomenon reconstruction as well as on the validity of the preservation, maintenance and restoration of large scaled cultural property by UAS photogrammetry. The test object is cltural heritage(treasure 1324) that is the rock-carved standing Bodhisattva in Soraesan Mountain, Siheung, documented in Goryeo Period(918-1392). This standing Bodhisattva has of particular interests since it's size is largest stone Buddha carved in a rock wall and is wearing a lotus shaped crown that is decorated with arabesque patterns. The positioning accuracy of UAS photogrammetry were compared with non-target total station survey results on the check points after creating 3D phenomenal models in real world coordinates system from photos, and also the quantified informations documented by Culture Heritage Administration were compared with UAS on the bodhisattva image of thin lines. Especially, tests the validity of UAS photogrammetry as a alternative method of visual inspection methods. In particular, we examined the effectiveness of the two techniques as well as the relative fluctuation of rock surface for about 2 years through superposition analysis of 3D points cloud models produced by both UAS image analysis and ground laser scanning techniques. Comparison studies and experimental results prove the accuracy and efficient of UAS photogrammetry in 3D phenomenon modeling, maintenance and restoration for various large-sized Cultural Heritage.