• 한국레이저가공학회지
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• 제17권4호
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• pp.14-19
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• 2014

Laser beam was applied on the boundary of the polyurethane and biodegradable polyacetate polymers. The distributed laser passed through the polyurethane layer and heated the polyacetate layer, then the soften acetate was squeezed thorough the 1mm square slots of polyurethane for the mechanical joining. The surface roughness ranging between $0.28{\mu}m$ and $3.06{\mu}m$ had almost no effect on joining strength, but the optical properties of HD (High Definition) and UHD (Ultra High Definition) mode affected laser beam transmittance. The optimum laser power was found to be between 8watt and 10watt with 500mm/min of scanning speed. The joining boundary was characterized by optical and SEM analysis. Based on the experiment and characterization results, the laser energy was effective for the polymer joining and efficiency of joining.

• 한국측량학회지
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• 제36권6호
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• pp.443-449
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• 2018

SLAM (Simultaneous Localization and Mapping) 기반 모바일 매핑 시스템을 활용한 실내 공간의 포인트 클라우드 취득은 건축물의 유지, 관리를 위한 as-built BIM (Building Information Model) 구축의 기초 공정이다. 본 연구에서는 다중 2D 레이저 스캐너로 구성된 모바일 매핑 시스템의 구축을 위한 시뮬레이션 기반 검정(calibration) 표적의 구조 결정 방법을 제안하였다. 2D 레이저 스캐너의 외부 표정요소 검정을 위해 (1) 원형, (2) 사각형, (3) 이중 원형, (4) 이중 사각형 형태의 표적을 구성하였다. 시뮬레이션을 통해 얻어진 각 표적 관측 값을 토대로, 최소제곱법 기반의 외부 표정요소 검정을 수행하였다. 그 결과 사각형 형태의 표적 구조가 주어진 시스템의 검정에 가장 적합한 형태임을 확인하였다. 또한 외부 표정요소 간의 높은 상관성을 확인할 수 있었으며, 표적의 구조에 따른 외부 표정요소의 검정 결과가 상이한 것으로 나타났다.

• 지구물리
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• 제9권1호
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• pp.7-19
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• 2006

Laser scanning is a new technology for obtaining Digital Surface Models(DSM) of the earth surface.It is a fast method for sampling the earth surface with high density and high point accuracy. This paper is for buildings extraction from LiDAR points data. The core part of building construction is based on a parameters filter for distinguishing between terrain and non-terrain laser points. The 3D geometrical properties of the building facades are obtained based on plane fitting using least-squares adjustment. The reconstruction part of the procedure is based on the adjacency among the roof facades. Primitive extraction and facade intersections are used for building reconstruction. For overcome the difficulty just reconstruct of laser points data used with digital camera images. Also, 3D buildings of city area reconstructed using digital map. Finally, In this paper show 3D building Modeling using digital map and LiDAR data.

• 한국통신학회논문지
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• 제34권10B호
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• pp.1117-1123
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• 2009

DMD(Digital Micro-mirror Device)와 갈바노 스캐너를 이용한 두부 고정형 다초점 디스플레이 시스템은 초점조절이 가능하여 스테레오스코픽 디스플레이에서 발생하는 양안의 수렴작용과 단안의 초점조절 작용의 불일치에 의한 눈의 피로 문제를 해결할 수 있는 디스플레이 시스템이다. 이 시스템은 레이저 스캐닝 방법으로 각 시점에 대한 영상의 수렴점을 형성하여 관찰자 동공에 제공함으로 초점조절이 가능토록 한다. 본 논문에서는 이 다초점 디스플레이 시스템의 레이저 스캐닝 방법을 수학적으로 분석하였고, 이러한 분석에 기반 한 다초점 시스템을 제작하여 비디오카메라를 통하여 초점조절이 가능함을 보였고, 결과적으로 레이저 스캐닝 방법에 의한 다초점 시스템의 시점 형성원리가 검증되었다.

• 한국정밀공학회지
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• 제23권5호
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• pp.143-148
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• 2006

It is still very difficult to generate a geometry model and finite element model, which has complex and many free surface, even though 3D CAD solutions are applied. Furthermore, in the medical field, which is a big growth area of recent years, there is no drawing. For these reasons, making a geometry model, which is used in finite element analysis, is very difficult. To resolve these problems and satisfy the requests of the need to create a 3D digital file for an object where none had existed before, new technologies are appeared recently. Among the recent technologies, there is a growing interest in the availability of fast, affordable optical range laser scanning. The development of 3D laser scan technology to obtain 3D point cloud data, made it possible to generate 3D model of complex object. To generate CAD and finite element model using point cloud data from 3D scanning, surface reconstruction applications have widely used. In the early stage, these applications have many difficulties, such as data handling, model creation time and so on. Recently developed point-based surface generation applications partly resolve these difficulties. However there are still many problems. In case of large and complex object scanning, generation of CAD and finite element model has a significant amount of working time and effort. Hence, we concerned developing a good direct finite element model generation method using point cloud's location coordinate value to save working time and obtain accurate finite element model.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.616-619
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• 2003

Photochemical and photothermal effects have correlation with each other and depend on laser wavelength. Multi-scanning laser ablation process of polymer with DPSS(Diode Pumped Solid State) 3rd harmonic Nd:YVO$_4$ laser with wavelength of 355nm is applied to fabricate three-dimensional micro shape. The DPSSL photomachining system can rapidly and cheaply fabricate 2D pattern or 3D shape with high efficiency because we only use CAD/CAM software and precision stages instead of complex projection mask. Photomachinability of polymer is highly influenced by laser wavelength and its own chemical structure. So the optical characteristics of polymers for 355nm laser source is investigated by experimentally and theoretically.

• 한국레이저가공학회지
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• 제18권4호
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• pp.6-11
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• 2015

Specially designed and 3D printed samples were prepared and joined by a diode laser source. To increase the strength of joining and reliability of samples, the surface was patterned by using a 3D printer. The joining surface was prepared as hemispherical shape with no-patterns, 0.5mm pitch, 0.75mm pitch and 1mm pitch. The optical properties of samples were measured by using an integrated sphere where classical Kubelka-Munk theory and modified Richard-Mudgetts theory for the analysis applied. Scanning speed was set at 500mm/min and laser power was varied between 9 and 10watts for the preliminary joining characteristic analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.689-692
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• 2002

To show a retina shape and thickness on the computer, a laser has been used in Scanning Laser Ophthalmoscope (SLO) equipment using the travelling difference. This method requires exact synchronize control of laser travelling in optic system to show this image. In this study, a synchronize control of the galvanometer to make 3-dimentional retina image. To obtain a clear 3-dimentional image, this exact synchronism is very Important for making perfect plane scanning.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 추계학술대회 논문집
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• pp.177-180
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• 2002

To show a retina shape and thickness on the computer monitor, a laser has been used in Scanning Laser Ophthalmoscope(SLO) equipment using the travelling difference. This method requires exact synchronous control of laser travelling in optic system to show a clear 3-dimensional image of retina. To obtain this image, this exact synchronism is very important for making the perfect plane scanning. In this study, a synchronous control of the galvanometer using deadbeat torque observer to make 3-dimensional retina image is presented. For the more, a very simple mathematical model of the galvanometer is approved by experimental result.

• 한국정보과학회논문지:시스템및이론
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• 제30권7_8호
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• pp.397-407
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• 2003

인간의 신체에 대한 정확한 3차원 표면모델을 추출할 수 있는 기술에 대한 요구와 관심이 최근 멀티미디어 등 다양한 응용 분야에서 증폭되고 있다. 본 논문에서는 인체의 ,3차원 모델을 효율적으로 추출하기 위한, 3차원 스캐너를 소개하였으며, 취득된 3차원 정보로부터 등고선(Wire-frame Contour)을 안정적으로 생성하는 반자동 등고선 생성 방법을 제안하였다. 또한 생성된 등고선으로부터 3차원 표면모델을 추출하기 위한 표면 삼각분할 알고리즘을 제안하였다. 실험을 통해 개발된 시스템과 제안된 방법이 안정적이고 효과적으로 인체의, 3차원 표면모델을 생성하는 것을 확인할 수 있었다.