• Journal of the Korean Society for Precision Engineering
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• v.33 no.4
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• pp.295-301
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• 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 $0.6{\mu}rad$.

• Journal of Internet of Things and Convergence
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• v.5 no.2
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• pp.15-20
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• 2019

As the machine learning research has developed, the field of translation and image analysis such as optical character recognition has made great progress. However, video translation that combines these two is slower than previous developments. In this paper, we develop an image translator that combines existing OCR technology and translation technology and verify its effectiveness. Before developing, we presented what functions are needed to implement this system and how to implement them, and then tested their performance. With the application program developed through this paper, users can access translation more conveniently, and also can contribute to ensuring the convenience provided in any environment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.683-686
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• 2002

It is fundamental to count and pack the pills in the medicine manufacture field but those tasks are time and labor consuming. Thus, the need fur automation of those tasks is necessarily getting increased in order to get effective mass production. It Is significant to perceive pills quickly and precisely. There were many trials for this processing but the performance of the existing counting machines varies about size, shape and dispersion tendency of pills. In this paper, the authors try to improve the counting performance of a pill counting machine that has optical sensors with the neural network. The passing signal of pill is acquired with optical sensor and the passage signal of the pill is extracted as input patterns. The gradient and integration of signal during passing time and the time keeping the pill interrupt the light from the LED are used as characteristic feature. The back propagation and perception algorithm are used for training. Experimental results with several pills show that the designed algorithm is a little bit effective to reduce the noise effect which is generated from interference among the machine components and unreliable environment.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.169-176
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• 2001

Defect of apple was depreciated the product value and causes storage disease seriously. To detect the defect of ‘Fuji’apple with machine vision system, the optical characteristics of defect should be investigated. In this research, absorbance spectra of defect were acquired by spectrophotometer in the range of visible and NIR region(400∼1,100nm) and L*a*b* color values were also acquired by colorimeter. NIR machine vision system was constructed with B&W camera, frame grabber, 16 tungsten-halogen lamps, variable focal length lens and NIR bandpass filter which was mounted to lens outward. Average gray values of defect at 15 NIR wavelength were acquired and the significant NIR wavelength was selected by comparing Mahalanobis distance between sound and defective apple. As the result of Mahalanobis distance analysis, the significant wavelength to discriminate the defectives in ‘Fuji’apple were found to be 720nm for scab and 970nm for bruise and cuts and 920nm was also effective regardless of defective types.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.4
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• pp.64-72
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• 1998

This paper a new approach to the design of machine vision technique with a camera modeling that accounts for major sources of geometric distortion, namely, radial, decentering, and thin prism distortion. Radial distortion causes an inward or outward displacement of a given image point from its ideal location. Actual optical systems are subject to various degrees of decentering , that is , the optical centers of lens design and manufacturing as well as camera assembly. It is our propose to develop the vision system for the pattern recognition and the automatic test of parts and to apply the line of manufacturing. The performance of proposed vision system is illustrated by simulation and experiment.

• International Journal of Reliability and Applications
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• v.9 no.1
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• pp.7-15
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• 2008

The dimensional measurement equipment, such as Coordinate Measurement Machine (CMM), Optical Coordinate Measurement Machine (OCMM), and Checking Fixture (CF), take multiple dimensional measurements for each part in an automobile industry. Measurements are also recorded under different measurement systems to see if the responses differ significantly over these systems. Each measurement system (CMM, OCMM, and CF) will be considered as different treatments. This set-up provides massive amounts of process data which are multivariate in nature. Therefore, the multivariate statistical analysis is required to analyze data that are dependent on each other. This research provides step by step methodology for the evaluation procedure of the compatibility of measurement systems and clarify a systematic analyzation among the different measurement system's compatibility followed by number of case studies for each methodologies provided.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.153-154
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• 2006

Development of sorting machine for photo diode and its control system is addressed. The sorting machine for optical communication device requires high positional precision because the alignment is one of the most important point in the sorting process. This sorting method describes how to detect the target chip's angle and position from the wafer. The machine vision system is used for the feedback control. This sorting machine is implemented by motion controller, machine vision and various solenoid valve and is interfaced with RS-232c, GPIB and PCI communication. This system gets the position accuracy within $1{\mu}m$ with our experiments.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.131-136
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• 2003

Five expensive sensors are necessary to control a magnetic bearing system. The sensor price rate of magnetic bearing system is high. So it is necessary that cheap and good sensor is developed. The optical fiber displacement sensor is adaptive to satisfy this condition. We can design magnetically suspended spindle based on static characteristic of optical fiber displacement sensor developed. The controller can be designed by decoupled feedback PD. Therefore, it is simpler than any other controller comparatively.

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

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.73-78
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• 2006

The occurrence of detrimental substances in the paper machine leads to reduced economic performance of paper mills through reduced capacities due to increased paper breaks and cleaning times. In this article the latest generation of BASF's laser optical pitch particle counter is employed in the examination of a paper mill operating two paper machines and using a mixture of thermo-mechanical pulp and recycled fibres. The potential of the new instrument to differentiate between particles on the basis of size and chemical composition is discussed. In addition, direct evidence of the periodic and locational variation of detrimental substances in the paper machine is given. Finally, an example of the application of BASF's laser optical pitch particle counter in the selection of a suitable fixative system for a complex furnish is presented.