• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.4
• /
• pp.295-301
• /
• 2016

The out-of-squareness is one of the error sources that affect the positioning accuracy of machine tools and coordinate measuring machines. Laser interferometer is widely used to measure the position and angular errors, and can measure the squareness using an optical square. However, the squareness measurement using the laser interferometer is difficult, as compared to other errors due to complicated optics setup and Abbe's error occurrence. The effect of out-of-squareness mainly appears at the face-diagonal of the movable plane. The diagonal displacements are also affected by the position dependent geometric errors. In this study, the squareness estimation techniques via diagonal displacement measurement using the laser interferometer without an optical square were proposed. For accurate estimation and measurement time reduction, the errors selected from proposed discriminant were measured. Discrepancy between the proposed technique with the laser interferometer (with an optical square) result was $0.6{\mu}rad$.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.10
• /
• pp.1451-1458
• /
• 2001

The effects of a specularly reflecting surface on the wall heat flux and medium temperature distribution are studied. The system is an infinite square duct enclosing an absorbing and emitting medium. The walls are opaque, and black or gray. The walls emit diffusely but reflect diffusely or speculary. Heat is transferred by the combined effect of conduction and radiation. The radiative heat transfer is analyzed using direct discrete-ordinates method. The parameters under study are conduction, to radiation parameter, optical depth, wall emissivity, and reflection characteristics. The specular reflection and diffuse reflection show sizeable differences when the conduction to radiation parameter is less than around 0.01. The differences appear only either on the side wall heat flux or on the medium temperature profiles for the range of this study. The differences on the side wall heat flux are observed for optical thickness less than around 0.1 However the differences on the medium temperate profiles are found for optical thickness greater than around 1. The difference increase with increasing reflectance. The specular reflection increases the well heat flux gradient along the side wall.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.9
• /
• pp.6254-6259
• /
• 2015

On the optical system and the system itself of the noise of the noise from the outside always present. This noise is to function as reducing performance of the optical system. Therefore, the probability of error, thereby changing the system. In this paper, the error probability of the optical system due to changes in various values by introducing the characteristic variable the value of the optical system was calculated using the ${\kappa}$-square method. Was confirmed also in accordance with the calculation result is an error probability of the optical system changes, it was confirmed that when the value of the holding case for holding the standard about 400 Lux on the probability of the optical system. This case was found to be an optical system using a light source with a low output, so that means the smaller output is no problem to maintain the error probability value of the optical system is large. This means that more effective and less expensive to implement because it means that the optical system does not require the use of pre-amplifier for amplifying the signal at the receiving end of an optical system using a light source with a low output when the normal case.

• Journal of the Optical Society of Korea
• /
• v.10 no.1
• /
• pp.23-27
• /
• 2006

We are studying the application of an adaptive optics system to upgrade the beam quality of a laser. The adaptive optics (AO) system consists of a bimorph deformable mirror, a Shack-Hartmann sensor and a control system. In most AO applications, the beam aperture is considered to be circular. However, in some cases such as laser beams from unstable resonators, the beam apertures are annulus or a holed-rectangle. In this paper, we investigate how well a bimorph deformable mirror of ${\Phi}120\;mm$ clear aperture can compensate phase distortions for three different beam configurations; 1) ${\Phi}120\;mm$ circular aperture, 2) ${\Phi}100\;mm$ annulus aperture with a ${\Phi}20\;mm$ hole and 3) $70\;mm{\times}70\;mm$ square aperture with a hole of $30\;mm{\times}30\;mm$. This study concludes that the bimorph mirror, which might be considered as a modal controller, can compensate tilt, defocus, coma and astigmatism, and spherical aberration for all three beams.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.407-408
• /
• 2009

• Proceedings of the Korea Multimedia Society Conference
• /
• 2002.05c
• /
• pp.299-302
• /
• 2002

컴퓨터를 이용한 독순 연구는 Man Machine Interface, 지적부호화에 있어서의 송신측 기술, 청각 장애인의 독순 훈련 시스템 등 다방면에서 그 응용이 기대된다. 본 논문은, 움직임 정보는 입술의 에지영역에 집중하고 있음에 주목하여, 입술 에지영역의 Optical Flow 추정값을 독순정보로 이용하는 방법을 제안한다. 휘도값을 갖지 않는 에지에, 선형 가상 휘도값를 정해주어 Optical Flow를 추정하는 VGM을 도입해 특징 파라미터를 계산하고, 마할라노비스 평방거리(Mahalanobis's square distance)에 기초한 최대우도판별함수를 이용하여 단모음을 분석하는 알고리즘을 제안한다.

• Journal of Korean Port Research
• /
• v.5 no.2
• /
• pp.77-84
• /
• 1991

This paper is compared with fourier series and least square polynomial fit and interpolation to mechanism stated number in electro-optical distance measuring instrument. Systematic instrumental errors occurring in electro-optical systems include uncertainties in the position of the electrical center of the transmitter, uncertainties in the effective center of the reflectors. frequency drift and instrument nonlinearity. Microwave systems are affected by uncertainties in the electrical centers of the master and remote units and by a phenomenon called group swing or reflection. As the result of this study, mechanism stated number will be used as verification of electro0optical measuring instrument to distance measurement.

• Proceedings of the Optical Society of Korea Conference
• /
• 2009.02a
• /
• pp.311-312
• /
• 2009

• Proceedings of the Optical Society of Korea Conference
• /
• 2005.02a
• /
• pp.260-261
• /
• 2005

• Proceedings of the Optical Society of Korea Conference
• /
• 2004.02a
• /
• pp.62-63
• /
• 2004