• Title, Summary, Keyword: Laser scanning

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Extraction of Coastal Topography Using Terrestrial Laser Scanning Technique (지상 레이저 스캐닝 기법을 이용한 해안 지형 추출)

  • Lee, Jong-Chool;Lee, Yong-Hee;Mun, Du-Yeoul;Seo, Dong-Ju
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • pp.435-438
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    • 2007
  • A laser scanning technique has been attracting much attention as a new technology to acquire location information. This technique might be applicable to a wide range of areas, most notably in geomatics, due to its high accuracy of location and automation of high-density data acquisition. In this study, the coastline was extracted using laser scanning. Through this laser scanning technique, efficient change detection of coast section can be ensured and also they can provide important information to be used when detecting a coast section in the future.

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Development of 3D Terrain Processing Platform Using Terrestrial Laser Scanning Data (지상레이저스캐닝 데이터를 활용한 3차원 지반지형 분석 플랫폼 개발)

  • Kim, Seok;Kim, Tae-Yeong
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.227-228
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    • 2016
  • Terrestrial laser scanning (TLS) technology is being applied to various fields such as the soil volume calculation and the displacement measurement of terrain, tunnels and dams. This study develops a 3D terrain processing platform for automated earth work using a terrestrial laser scanning data as the software prototype. The developed software provides cells with geo-technical information for planning work to an integrated system.

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Characterization of Wavelength Swept Laser with a Scanning Frequency at 1300 nm (1300 nm 대역 파장 훑음 레이저의 훑음 주파수에 따른 출력 특성)

  • Lee, Byoung-Chang;Oh, Min-Hyun;Jeon, Min-Yong
    • Korean Journal of Optics and Photonics
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    • v.20 no.3
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    • pp.189-194
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    • 2009
  • We demonstrate a ring type wavelength swept laser incorporating a fiber Fabry-Perot tunable filter in a laser cavity using 1300 nm semiconductor optical amplifier as a gain medium. The output characteristics of the wavelength swept laser according to the applied scanning frequencies are analyzed in the temporal and spectral domain. The output of the wavelength swept laser decreases dramatically as the scanning frequency increases. And there is a significant peak power imbalance between the forward scan and the backward scan as the scanning frequency increases. Its use in practical applications might be limited.

The Effects of a Er:YAG Laser on Machined, Sand-Blasted and Acid-Etched, and Resorbable Blast Media Titanium Surfaces Using Confocal Microscopy and Scanning Electron Microscopy

  • Park, Jun-Beom;Kim, Do-Young;Ko, Youngkyung
    • Journal of Korean Dental Science
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    • v.9 no.1
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    • pp.19-27
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    • 2016
  • Purpose: Laser treatment has become a popular method in implant dentistry, and lasers have been used for the decontamination of implant surfaces when treating peri-implantitis. This study was performed to evaluate the effects of an Erbium-doped:Yttrium-Aluminum-Garnet (Er:YAG) laser with different settings on machined (MA), sand-blasted and acid-etched (SA), and resorbable blast media (RBM) titanium surfaces using scanning electron microscopy and confocal microscopy. Materials and Methods: Four MA, four SA, and four RBM discs were either irradiated at 40 mJ/20 Hz, 90 mJ/20 Hz, or 40 mJ/25 Hz for 2 minutes. The specimens were evaluated with scanning electron microscopy and confocal microscopy. Result: The untreated MA surface demonstrated uniform roughness with circumferential machining marks, and depressions were observed after laser treatment. The untreated SA surface demonstrated a rough surface with sharp spikes and deep pits, and the laser produced noticeable changes on the SA titanium surfaces with melting and fusion. The untreated RBM surface demonstrated a rough surface with irregular indentation, and treatment with the laser produced changes on the RBM titanium surfaces. The Er:YAG laser produced significant changes on the roughness parameters, including arithmetic mean height of the surface (Sa) and maximum height of the surface (Sz), of the MA and SA surfaces. However, the Er:YAG laser did not produce notable changes on the roughness parameters, such as Sa and Sz, of the RBM surfaces. Conclusion: This study evaluated the effects of an Er:YAG laser on MA, SA, and RBM titanium discs using confocal microscopy and scanning electron microscopy. Treatment with the laser produced significant changes in the roughness of MA and SA surfaces, but the roughness parameters of the RBM discs were not significantly changed. Further research is needed to evaluate the efficiency of the Er:YAG laser in removing the contaminants, adhering bacteria, and the effects of treatment on cellular attachment, proliferation, and differentiation.

A Study on Three-Dimensional Model Reconstruction Based on Laser-Vision Technology (레이저 비전 기술을 이용한 물체의 3D 모델 재구성 방법에 관한 연구)

  • Nguyen, Huu Cuong;Lee, Byung Ryong
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.7
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    • pp.633-641
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    • 2015
  • In this study, we proposed a three-dimensional (3D) scanning system based on laser-vision technique and rotary mechanism for automatic 3D model reconstruction. The proposed scanning system consists of a laser projector, a camera, and a turntable. For laser-camera calibration a new and simple method was proposed. 3D point cloud data of the surface of scanned object was fully collected by integrating extracted laser profiles, which were extracted from laser stripe images, corresponding to rotary angles of the rotary mechanism. The obscured laser profile problem was also solved by adding an addition camera at another viewpoint. From collected 3D point cloud data, the 3D model of the scanned object was reconstructed based on facet-representation. The reconstructed 3D models showed effectiveness and the applicability of the proposed 3D scanning system to 3D model-based applications.

A Study on the Improvement of Repair and Reinforcement Quantity Take-off in Fire-damaged Area Using 3D Laser Scanning (3D Laser Scanning을 활용한 화재 손상 부위의 보수·보강 물량 산출 방식 개선에 관한 연구)

  • Jeong, Hoi-Jae;Ham, Nam-Hyuk;Lee, Byoung-Do;Park, Kwang-Min;Kim, Jae-Jun
    • Journal of KIBIM
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    • v.9 no.1
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    • pp.11-21
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    • 2019
  • Recently, there is an increase in fire incidents in building structures. Due to this, the importance of fire-damaged buildings' safety diagnosis and evaluation after fire is growing. However, the existing fire-damaged safety diagnosis and evaluation methods are personnel-oriented, so the diagnostic results are intervened by investigators' subjectivity and unquantified. Thus, improper repair and reinforcement can result in secondary damage accidents and economic losses. In order to overcome these limitations, this study proposes using 3D laser scanning technology. The case analysis of fire-damaged building structures was conducted to verify the effectiveness of accuracy and manpowering by comparing the existing method and the proposed method. The proposed method using 3D laser scanning technology to obtain point cloud data of fire-damaged field. The point cloud data and BIM model is combined to inspect the fire-damaged area and depth. From inspection, quantified repair and reinforcement quantity take-off can be acquired. Also, the proposed method saves half of the manpowering within same time period compared to the existing method. Therefore, it seems that using 3D laser scanning technology in fire-damaged safety diagnosis and evaluation will improve in accuracy and saving time and manpowering.

Development of An Automated Scanning Laser Doppler Vibrometer for Measurements of In-Plane Structural Vibration (평면 구조 진동 측정을 위한 자동화된 스캐닝 레이저 도플러 진동측정기의 개발 및 연구)

  • Kil, Hyun-Gwon
    • Journal of KSNVE
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    • v.7 no.2
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    • pp.231-238
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    • 1997
  • An automated scanning laser Doppler vibrometer (LDV) has been designed, and built to measure in-plane vibration fields over structures. Use of optical fibers allows the compact design of a laser probe head which can be scanned over the vibrating structures. An algorithm for automated self-alignment of the laser probe is developed. The system is completely automated for scanning over the structures, focusing two laser beams at each data point until the detected vibration signal is stable, and for recording and transferring the data to a system computer. The automated system allows one to get extensive data of the vibration field over the structures. The system is tested by scanning a piezoelectric cylindrical shell and a plate excited by a continuous signal and by a pulse signal, respectively. Results show that the automated scanning LDV system can be a useful tool to measure the in-plane vibration field and to detect the elastic waves propagating on the vibrating structures.

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Long Distance and High Resolution Three-Dimensional Scanning LIDAR with Coded Laser Pulse Waves (레이저 펄스 부호화를 이용한 원거리 고해상도 3D 스캐닝 라이다)

  • Kim, Gunzung;Park, Yongwan
    • Korean Journal of Optics and Photonics
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    • v.27 no.4
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    • pp.133-142
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    • 2016
  • This paper presents the design and simulation of a three-dimensional pixel-by-pixel scanning light detection and ranging (LIDAR) system with a microelectromechanical system (MEMS) scanning mirror and direct sequence optical code division multiple access (DS-OCDMA) techniques. It measures a frame with $848{\times}480$ pixels at a refresh rate of 60 fps. The emitted laser pulse waves of each pixel are coded with DS-OCDMA techniques. The coded laser pulse waves include the pixel's position in the frame, and a checksum. The LIDAR emits the coded laser pulse waves periodically, without idle listening time to receive returning light at the receiver. The MEMS scanning mirror is used to deflect and steer the coded laser pulse waves to a specific target point. When all the pixels in a frame have been processed, the travel time is used by the pixel-by-pixel scanning LIDAR to generate point cloud data as the measured result.

Utilizing 3D Laser Scanning Technology for Remodeling Work of Building Inside

  • Lee, Jin-Duk;Han, Seung-Hee;Lee, Jae-Bin
    • International Journal of Contents
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    • v.5 no.3
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    • pp.19-23
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    • 2009
  • Laser scanning technology is a maturing measurement technology which is capable of obtaining 3D measurement data of objects with high-accuracy, high-resolution and in a short time. Laser scanners are used more and more as surveying instruments for various applications. This paper describes the procedure of 3D data acquirement using terrestrial LiDAR and section drawing extraction through a series of processing for remodeling the interior of a department building. Accurate drawings are needed for improvement construction of building interior. However if the design drawings of that time of construction work were lost or damaged or actual dimensions of drawings differ from those of design drawings, the interior should be resurveyed. In this study, the extraction process of interior plane figures were suggested through using laser scanning and related reverse engineering software

Extraction of Coast Topographic Information Using Mobile Laser Scanning and Airborne LiDAR (지상레이저스캐너와 항공라이다를 이용한 해안 지형정보 추출)

  • Lee, In-Su;Tcha, Dek-Kee;Kim, Su-Jeong
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • pp.115-117
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    • 2009
  • Terrestrial Laser Scanner and Airborne Laser Scanning is one of the state of art surveying equipments. So This study deals with the combined use of mobile TLS(Terrestrial Laser Scanner) with ALS(Airborne Laser Scanning) to extract shoreline's topography information. These two systems have their own pros and cons. Mobile TLS can capture the facades of a low story building along the shoreline fast and quickly. Meanwhile, Due to viewpoint restrictions of ALS data collection, the amount of detail, which is available for the building facades is very limited. Therefore, it is recommended that the co-registration and geo-referencing methods of both two should be developed and the application of both system for shoreline mapping also should be investigated.

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