• 한국지리정보학회지
• /
• 제9권3호
• /
• pp.207-218
• /
• 2006

도로교통 안전진단에 있어 도로의 형상분류를 통한 도로 선형 및 횡단면 데이터의 추출은 매우 중요한 작업이다. 기존의 조사원에 의한 도로안전진단은 많은 시간과 비용이 요구되는 반면 도로안전진단을 위한 다양한 정보를 제공하지 못한다는 단점이 있다. 따라서, 레이저 스캐닝 장치를 장착한 차량측량시스템을 이용, 수치사진측량시스템 기술을 활용하여 자동으로 도로형상을 분류하고, 도로 선형 및 횡단면 데이터를 추출하는 방안이 필요하다. 본 논문에서는 이를 위해 모바일 레이저 스캐닝 데이터를 취득하여 처리하고, 이를 통해 도로 선형 및 횡단면 데이터를 추출할 수 있는 방안을 제시하고, GPS-VAN 을 이용 취득된 모바일 레이저 스캐닝 데이터를 처리, 도로 선형 및 횡단면 데이터를 추출하는 연구를 진행하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.273-277
• /
• 2003

A general process of electronic assembly is composed of a series of geometric alignments and bonding/screwing processes. After assembly, the function is tested in a following process of inspection. However, assembly of micro-optic devices requires both processes to be performed in equipment. Coarse geometric alignment is made by using vision and optical function is improved by the following fine motion based on feedback of tunable laser interferometer. The general system is composed of a precision robot system for 3D assembly, a 3D vision guided system for geometric alignment and an optical feedback system with a tunable laser. In this study, we propose a new fast alignment algorithm of micro-optic devices for both of visual and optical alignments. The main goal is to find a fastest alignment process and algorithms with state-of-the-art technology. We propose a new approach with an optimal sequence of processes, a visual alignment algorithm and a search algorithm for an optimal optical alignment. A system is designed to show the effectiveness and efficiency of the proposed method.

• 한국정밀공학회지
• /
• 제17권9호
• /
• pp.75-80
• /
• 2000

Although laser interferometer is widely accepted as a tool for measurement of motion accuracy the set-up procedure is time-consuming because of the strict requirement on alignment between laser head and optic units. This paper presents a 4-axis auto-aligning system which is useful for easy set-up of laser interferometer so as to evaluate precision of a 2-axis feeding system. This paper proposes two ideas for alignment in laser interferometer set-up: one is use of mirror and retroreflectors. and the other is taking advantage of the pre-defined movement and peculiar characteristic of retroreflecotrs. The pros and cons of the two methods are discussed. Illustrative experimental results are presented in which the developed system is applied to a XY table.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
• /
• pp.120.2-120.2
• /
• 2015

We propose a novel direct writing technique with a femtosecond laser enabling selective modification of not only the morphology of conducting polymer thin films but also the orientation and alignment of the polymer crystal. Surface relief gratings resulting from photoexpansion on P3HT:PCBM and PEDOT:PSS thin films were fabricated by femtosecond laser direct writing. The photoexpansion was induced at laser fluence below the ablation threshold of the thin film. The morphology (size and shape) of photoexpansion could be quantitatively controlled by laser writing parameters such as focused beam size, writing speed, and laser fluence. GIWAX results showed that face-on P3HT crystals were largely increased in the photoexpansion in comparison with pristine region of the thin film. In addition, the face-on P3HTs in the photoexpansion were aligned with their orientation along the polarization of the laser. The micro-RAMAN spectra confirmed that neither chemical composition change nor the polymer chain breaking was observable after femtosecond laser irradiation. We believe that this laser direct writing technique opens a new door to the fabrication of more efficient OPVs via non-contact, toxic-free approach.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2008년도 춘계학술대회논문집
• /
• pp.389-392
• /
• 2008

The thrust axis alignment of the launch vehicle is very important because of the misalignment causes the unstable attitude control and results in mission failure. Generally, optical methods such as digital theodolite and laser tracker and mechanical method such as turn table method are used to thrust axis alignment. This article deals with the simple method of thrust axis alignment of Kick Motor.

• 정보저장시스템학회논문집
• /
• 제7권2호
• /
• pp.53-59
• /
• 2011

We have developed a compact and high-power mode-locked fiber laser for multilayered optical memory. Fiber lasers have the potential to be compact and stable light sources that can replace bulk solid-state lasers. To generate high-power pulses, we used stretched-pulse mode locking. The average power and pulse width of the output pulse from the fiber laser that we developed were 109 mW and 2.1 ps, respectively. The dispersion of the output pulse was compensated with an external single-mode fiber of 2.5 m length. The pulse was compressed from 2.1 ps to 93 fs by dispersion compensation. The fiber laser we have developed is possible to use as a light source of multilayered optical memory. We also present a fiber confocal microscope as an alignment-free readout system of multilayered optical memories. The fiber confocal microscope does not require fine pinhole position alignment because the fiber core is used as the point light source and the pinhole, and both of which are always located at the conjugated point. The configuration reduces the required accuracy of pinhole position alignment. With these techniques we can present an all-fiber recording and readout system for multilayered memories.

• 한국광학회지
• /
• 제11권4호
• /
• pp.279-288
• /
• 2000

다양한 종류의 펄스형 Nd:YAG 레이저 공진기를 구성하여 출력경의 각도변화에 따른 레이저 출력에너지의 변화를 최대 출력에너지가 반으로 줄어드는 점의 각도변위인 반치폭 (FWHM)을 측정하여 비교하였다. 출력경의 기울어짐에 대하여 높은 반치폭을 갖고 반사경의 각도변화에 대해서도 덜 민감하게 반응하는 안정적인 펄스형 고체 레이저의 새로운 공지기를 구성하였다. ABCD 광선 전파 행렬식을 이용하여 이러한 공지기의 전파행렬식이 단위행렬이 됨을 해석함으로서 높은 정렬 안정성을 가지고 있음을 증명하였다.

• Journal of the Optical Society of Korea
• /
• 제9권1호
• /
• pp.1-5
• /
• 2005

Using tightly focused femtosecond laser pulses, we produce an optical waveguide and optical devices in transparent materials. This technique has the potential to generate not only channel waveguides, but also three-dimensional optical devices. In this paper, an optical splitter and U-grooves, which are used for fiber alignment, are simultaneously fabricated in a fused silica glass using near-IR femtosecond laser pulses. The fiber aligned optical splitter has a low insertion loss, less than 4㏈, including an intrinsic splitting loss of 3㏈ and excess loss due to the passive alignment of a single-mode fiber. Finally, we demonstrate the utility of the femtosecond laser writing technique by fabricating gratings at the surface and inside the silica glass.

• 한국주조공학회지
• /
• 제21권5호
• /
• pp.290-295
• /
• 2001

We fabricated test samples containing various shape elements and surface roughness checking points for the jewelry cast master patterns by employing the 3D computer aided design (CAD), selective laser sintering (SLS) rapid prototype (RP) with the DuraForm powders. We varied the alignment angle from $0^{\circ}$ to $10^{\circ}$ at a given layer thickness of 0.08 and 0.1mm, respectively, in RP operation. Dimensions of the shape elements as well as values of surface roughness are characterized by an optical microscope and a contact-scanning profilometer. Surface roughness values of the top and vertical face increased as the alignment angle increased, while the other roughness values and shape elements variation were not depending on the alignment angle. The resolution of the shape realization was enhanced as the layer thickness became smaller. The minimum diameter of the hole, common in jewelry design, was 1.2 mm, and the shrinkage became 12% at the 1.6 mm-diameter hole, Our results implied that we face down the proposed design elements with $0^{\circ}$ alignment angle, and consider the shrinkage effect of each shape element in DuraForm RP jewelry modeling.

• 한국항공우주학회지
• /
• 제39권3호
• /
• pp.279-288
• /
• 2011

본 논문에서는 정지궤도 위성 통신 안테나의 지향 및 장착위치를 정확하게 하기 위한 정밀정렬 방법과 그 측정 결과를 다룰 예정이다. 안테나의 지향 및 장착위치 관점에서 최적의 성능을 획득하기 위해 무중력상태가 모사되었으며 레이저추적 시스템과 데오드라이트 시스템이 적용되었다. 그 결과 정렬 안정성이 허용오차 ${\pm}\;0.25mm$ 및 ${\pm}\;0.013^{\circ}$ 이내에서 검증되었으며, Ka 대역 전개형 안테나의 최종 정렬은 허용오차 ${\pm}\;0.5mm$ 및 ${\pm}\;0.015^{\circ}$ 이내인 요구조건을 만족할 수 있었다.