• Progress in Superconductivity
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• 제13권3호
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• pp.169-177
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• 2012

Distribution of the local properties in GdBCO and YBCO coated conductors was investigated using Low-temperature Scanning Laser and Hall Probe Microscopy (LTSLHPM). We prepared GdBCO and YBCO coated conductors to study the spatial distribution of the current density in a single bridge. Inhomogeneity of the ${T_c}^{max}$ in the bridge was analyzed from experimental results of Scanning Laser Microscopy (SLM) near the superconducting transition. The local transport and screening current in the bridge were also investigated using Scanning Hall Probe Microscopy (SHPM). A series of line scans of SLM of the GdBCO and YBCO sample showed that lines with more inhomogeneous distributions of ${\delta}V$ had more inhomogeneous distributions of ${T_c}^{max}$. The defect of the superconducting layer of the GdBCO sample caused by damage to the substrate affected the current flow. And we could analyze the redistribution of the current density using SLM and SHPM.

• 한국생산제조학회지
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• 제24권1호
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• pp.1-6
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• 2015

To improve the efficiency of a reverse engineering process, many researches have recently tried to develop efficient, automatic 3D scanning devices. A new automatic 3D scanning device using a spherical coordinate system mechanism is introduced in this study. This device incorporates a guide motion along the spherical coordinate to compound each 3D data point automatically. The experiments correlating the system assembling tolerance with the form accuracy were conducted to verify the efficiency of the system for the scanning of an object, including complex shapes and manifold sections. In addition, the required time and system accuracy, taken during the scanning process of complicated artifact models, were investigated. Further, based on these empirical results, it was ascertained that the superior productivity of this new device offers a more precise and efficient scan when compared to conventional methodologies.

• 한국건축시공학회지
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• 제20권2호
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• pp.191-198
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• 2020

건설산업에도 스마트 건설기술들이 많이 도입되고 있으며, 여러 기술 중 3D 스캐닝과 BIM을 이용한 품질관리를 시도하는 회사가 증가하고 있다. 따라서 본 연구에서 3D 스캐닝과 BIM을 현장 품질점검 사례에 적용하여 활용가능성과 효용성을 확인하였다. 그 결과 3D 스캐닝과 BIM을 활용한 품질점검은 기존에 시행했던 품질점검보다 시간적으로 단축되고 적은 인력으로도 실현이 가능하다는 것을 확인하였다. 따라서 품질점검의 다양한 분야에 3D 스캐닝과 BIM을 활용한 기술을 적용할 수 있을 것으로 사료된다.

• 한국IT서비스학회지
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• 제11권sup호
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• pp.103-111
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• 2012

In epigraph field to study ancient scripts, alternative readability improvement technologies have been developed to replace existing rubbing method which has low resolution and causes surface pollution of heritages from the viewpoints of extraction process and used materials. Recently many methods which are based on analysis of pixel data for extracting outlines of the specific image have been developed with advancement of image processing techniques. But these methods are not applicable and the results are not satisfied in the damaged inscriptions which are weathered by wind and rain for a long time and in the narrowed one. In this paper laser scanning techniques which uses optical triangulation measurement principle are developed to minimize scanning error. The proposed techniques are consisted of 3 parts：(1) the understanding of optical triangulation measurement principle to find scanning guideline (2) determinations of points interval, scanning distance and scanning angle to guarantee scanning data quality (3) identification of valid point data area which will be used in registration process. The proposed character identification method contributed in decoding an ancient inscription on SeukBingGo in Kyungju.

• 한국통신학회논문지
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• 제42권4호
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• pp.785-790
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• 2017

네트워크 기반 단말 정보 식별 도구는 일반적으로 포트 스캔을 사용해 네트워크 단말들의 정보를 탈취하고 취약점을 찾아낸다. 특히 Shodan과 Censys는 네트워크 기반 단말 정보 식별 도구를 이용하여 광범위한 단말 정보를 탈취하여 데이터베이스에 저장한 후, 이를 사용자에게 제공한다. 이 정보는 누구나 확인할 수 있기 때문에 사이버 공격에 악용될 수 있다. 따라서 네트워크 단말 정보 탈취 방지가 필요하며, 이를 위해서는 스캔 도구가 사용하는 스캐닝 방법을 알아야한다. 하지만 Shodan과 Censys가 사용하는 스캐닝 방법은 잘 알려져 있지 않다. 따라서 본 논문에서는 Shodan과 Censys의 스캐닝 방법을 추정해 모델링하고 성능을 분석하였다.

• 한국정밀공학회지
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• 제21권3호
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• pp.171-179
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• 2004

Micro-stereolithography technology has made it possible to fabricate a freeform 3D microslructure. This technology is based on conventional stereolithography, in which a UV laser beam irradiates the open surface of a UV-curable liquid photopolymer, causing it to solidify. In micro-stereolithography, a laser beam of a few $\mu m$ diameter is used to solidify a very small area of the photopolymer. This is one of the key technological elements, and can be achieved by using a focusing lens. Thus, the solidification phenomena of the liquid photopolymer must be carefully investigated. In this study, the photopolymer solidification phenomena in response to variations in the scanning pitch of a focused laser beam was investigated experimentally. The effect of layer thickness on the solidification width and depth was also examined. These studies were conducted under the conditions of relatively lower laser power and relatively higher scanning speed. Moreover, the photopolymer solidification phenomena for the relatively higher laser power and lower scanning speed was investigated, too. In this case, comparing to the case of lower laser power and higher scanning speed, the photopolymer absorbed large amount of irradiation energy of the laser beam. These results were compared with those obtained from a photopolymer solidification model. From these results, a new laser-scanning scheme was proposed according to the shape of the 3D model. Samples by each method were fabricated successfully.

• 보존과학회지
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• 제35권1호
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• pp.71-80
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• 2019

This study examined the applicability of digital technologies based on three-dimensional(3D) scanning, modeling, and printing to the restoration of damaged artifacts. First, 3D close-range scanning was utilized to make a high-resolution polygon mesh model of a roof-end tile with a missing part, and a 3D virtual restoration of the missing part was conducted using a haptic interface. Furthermore, the virtual restoration model was printed out with a 3D printer using the material extrusion method and a PLA filament. Then, the additive structure of the printed output with a scanning electron microscope was observed and its shape accuracy was analyzed through 3D deviation analysis. It was discovered that the 3D printing output of the missing part has high dimensional accuracy and layer thickness, thus fitting extremely well with the fracture surface of the original roof-end tile. The convergence of digital virtual restoration based on 3D scanning and 3D printing technology has helped in minimizing contact with the artifact and broadening the choice of restoration materials significantly. In the future, if the efficiency of the virtual restoration modeling process is improved and the material stability of the printed output for the purpose of restoration is sufficiently verified, the usability of 3D digital technologies in cultural heritage restoration will increase.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.1016-1023
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• 2022

In proton therapy, a highly conformal proton dose can be delivered to the tumor by means of the steep distal dose penumbra at the end of the beam range. The proton beam range, however, is highly sensitive to range uncertainty, which makes accurately locating the proton range in the patient difficult. In-vivo range verification is a method to manage range uncertainty, one of the promising techniques being prompt gamma imaging (PGI). In earlier studies, we proposed gamma electron vertex imaging (GEVI), and constructed a proof-of-principle system. The system successfully demonstrated the GEVI imaging principle for therapeutic proton pencil beams without scanning, but showed some limitations under clinical conditions, particularly for pencil beam scanning proton therapy. In the present study, we upgraded the GEVI system in several aspects and tested the performance improvements such as for range-shift verification in the context of line scanning proton treatment. Specifically, the system showed better performance in obtaining accurate prompt gamma (PG) distributions in the clinical environment. Furthermore, high shift-detection sensitivity and accuracy were shown under various range-shift conditions using line scanning proton beams.

• 한국건설관리학회논문집
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• 제25권3호
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• pp.68-82
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• 2024

The planning stage of laser scanning is crucial for acquiring high-quality 3D source data. It involves assessing the target space's environment and formulating an effective measurement strategy. However, existing practices often overlook on-site conditions, with decisions on scanner deployment and scanning locations relying heavily on the operators' experience. This approach has resulted in frequent modifications to scanning locations and diminished 3D data quality. Previous research has explored the selection of optimal scanner locations and conducted preliminary reviews through simulation, but these methods have significant drawbacks. They fail to consider scanner inaccuracies, do not support the use of multiple scanners, rely on less accurate 2D drawings, and require specialized knowledge in 3D modeling and programming. This study introduces an optimization technique for laser scanning planning using 3D simulation to address these issues. By evaluating the accuracy of scan data from various laser scanners and their positioning for scanning a retaining wall structure in a small-scale building, this method aids in refining the laser scanning plan. It enhances the decision-making process for end-users by ensuring data quality and reducing the need for plan adjustments during the planning phase.

• 감성과학
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• 제17권2호
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• pp.111-122
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• 2014

본 연구는 지하철 로비공간을 대상으로 한 주시실험을 통해 공간정보의 본능적 시선탐색과정에서 나타나는 주시특성에 나타난 주사경로 알고리즘을 분석하였다. 주시기간 구간별 분석에서 주시시간이 오래 경과할수록 주사유형 횟수가 증가하고 있었는데, 오래 주시할수록 주시단절이 많이 일어난 것으로 해석이 가능하며, 주시에 따른 피로나 활발한 탐색이 자연스러운 공간탐색과정에서 일어나는 과정에서 화상범위를 벗어나는 경우가 많았던 것으로 보인다. 또한 시간구간의 변화에 따른 주사유형의 변화를 추세선으로 살펴본 결과, "집중"은 시간구간의 증가와 함께 가파른 증가, "대각 수직"은 완만한 증가를 보이는 반면, "순환 혼합 수평"은 감소 경향을 보이고 있다. 공간을 주시한 피험자의 주시데이터에는 다양한 시각정보가 포함되어 있는데, "주의집중"에 나타난 주사유형을 분석한 결과, 이상과 같은 의미 있는 결론을 도출할 수 있었다. 이러한 주사유형의 증감특성은 시간의 경과에 따른 주사경향을 파악함에 있어 기초자료가 될 수 있다.