• Journal of the Korean Society for Precision Engineering
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• v.26 no.8
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• pp.72-78
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• 2009

We developed a line standards measurement system using an optical microscope and measured two kinds of line standards. It consists of three main parts: an optical microscope module including a CCD camera, a stage system with a linear encoder, and a measurement program for a microscopic image processing. The magnification of microscope part was calibrated using one-dimensional gratings and the angular motion of stage was measured to estimate the Abbe error. The threshold level in line width measurement was determined by comparing with certified values of a line width reference specimen, and its validity was proved through the measurement of another line width specimen. The expanded uncertainty (k=2) was about 100 nm in the measurements of $1{\mu}m{\sim}10{\mu}m$ line width. In the comparison results of line spacing measurement, two kinds of values were coincide within the expanded uncertainty, which were obtained by the one-dimensional measuring machine in KRISS and the line standards measurement system. The expanded uncertainty (k=2) in the line spacing measurement was estimated as $\sqrt{(0.098{\mu}m)^2+(1.8{\times}10^{-4}{\times}L)^2}$. Therefore, it will be applied effectively to the calibration of line standards, such as line width and line spacing, with the expanded uncertainty of several hundreds nanometer.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.287-287
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• 1994

In the present study, it was aimed to asses the possibility that calcitonin gene-related peptide (CGRP) released in response to transient hypotension may contribute to the reflex autoregulation of cerebral blood flow as a putative modulator. Changes in pial arterial diameter (mean, 33.0 ${\pm}$ 1.1 $\mu\textrm{m}$) with changes in systemic arterial blood pressure (mean, 101.9 ${\pm}$ 2.7 mmHg) were observed directly through a closed cranial window in anesthetized normotensive rats. Image of the pial vessels was captured with a stereoscope connected to a CCD video camera and the diameter was measured with a microscaler. In the capsaicin-treated rats (one day prior to experiment, 50 nmol capsaicin injected intracisternally), both vasodilater and vasoconstrictor responses evoked by a transient hypotension and the reverse of blood pressure were markedly attenuated or almost abolished. When changes in pial arterial diameter were plotted as a function of changes in blood pressure, the slopes of both regression lines (for vasodilators and vasoconstrictors ) were markedly reduced. Similar reductions were evidenced under treatment wi th the CGRP antibody serum (1:1,000) and following CGRP receptor desensitization. However, the autoregulatory mechanics were neither affected by treatment wi th spantide (1 ${\mu}$M), substance P antagonist, nor by substance P receptor desensitization. Suffusion wi th mock cerebrospinal fluid containing CGRP and cromakalim caused a vasodilatation in a concentration-dependent manner, respectively and their effects were antagonized by glibenclamide. Substance P produced a vasodilatation, which was, however, little affected by glibenclamide. These observations indicate that the CGRP released from the perivascular sensory fibers in response to a hypotension is implicated in the modulation of the autoregulation of cerebral blood flow.

• Journal of Biosystems Engineering
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• v.26 no.6
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• pp.571-578
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• 2001

Production of green pepper has increased for ten years in Korea, as customer's preference of a pepper tuned to fiesta one. This study was conducted to develop an on-line fading algorithm of green pepper using machine vision and aimed to develop the automatic on-line grading and sorting system. The machine vision system was composed of a professive scan R7B CCD camera, a frame grabber and sets of 3-wave fluorescent lamps. The length and curvature, which were main quality factors of a green pepper were measured while removing the stem region. The first derivative of the thickness profile was used to remove the stem area of the segmented image of the pepper. A new boundary was generated after the stem was removed and a baseline of a pepper which was used for the curvature determination was also generated. The developed algorithm showed that the accuracy of the size measurement was 86.6% and the accuracy of the bent was 91.9%. Processing time spent far grading was around 0.17 sec per pepper.

• Korean Journal of Optics and Photonics
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• v.15 no.1
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• pp.39-45
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• 2004

A computer simulation about removal of the 0-th order diffraction is achieved by using numerical reconstruction in digital holography and the Fourier transform method. A light intensity distribution hologram is generated through numerical calculation of the interference pattern. Additionally a phase hologram without the 0-th order diffraction is generated. The removal function for elimination of the 0-the order diffraction is introduced and the numerical reconstructions with several conditions for the removal of the 0-th order diffraction and the production of high quality numerically reconstructed images are tested and compared. The removal function is proven to be more effective at the suppression of the 0-th order diffraction compared with the DC suppression method.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.561-564
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• 2004

Crack sealing automation machines' have been continually developed since the early 1990's because of the effectiveness of crack sealing that would be able to improve safety, quality and productivity. It has been considered challenging problem to detect crack network in pavement which includes noise (oil marks, skid marks, previously sealed cracks and inherent noise). It is required to develop crack network mapping and modeling algorithm in order to accurately inject sealant along to the middle of cut crack network. The primary objective of this study is to propose a crack network mapping and modeling algorithm using neural network for improving the accuracy of the algorithm used in the APCS. It is anticipated that the effective use of the proposed algorithms would be able to reduce error rate in image processing for detecting, mapping and modeling crack network as well as improving quality and productivity compared to existing vision algorithms.

• Journal of The Korean Astronomical Society
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• v.38 no.4
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• pp.463-470
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• 2005

In this paper, we have made the component-based development of observational software for KASI solar imaging spectrograph (KSIS) that is able to obtain three-dimensional imaging spectrograms by using a scanning mirror in front of the spectrograph slit. Since 2002, the KASI solar spectrograph has been successfully operated to observe solar spectra for a given slit region as well as to inspect the response functions of narrow band filters. To improve its capability, we have developed the KSIS that can perform sequential observations of solar spectra by simultaneously controlling the scanning mirror and the CCD camera via Visual C++. Main task of this paper is to introduce the development of the component-based software for KSIS. Each component of the software is reusable on the level of executable file instead of source code because the software was developed by using CBD (component-based development) methodology. The main advantage of such a component-based software is that key components such as image processing component and display component can be applied to other similar observational software without any modifications. Using this software, we have successfully obtained solar imaging spectra of an active region (AR 10708) including a small sunspot. Finally, we present solar $H{\alpha}$ spectra ($6562.81{\AA}$) that were obtained at an active region and a quiet region in order to confirm the validity of the developed KSIS and its software.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.9
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• pp.807-813
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• 2015

In the present study, an interferometer system, which integrates the laser sensitivity control technique based on the theory of electronic speckle pattern interferometry, one of non-contact non-destructive analysis methods, was developed. This interferometry system receives an image from CCD cameras for each reference and object, and compares the photosensitivity of the object and reference images from imagification. For the purpose of this study, the photosensitivity of object and reference light is measured with power meters, and the amount of light was controlled with an ND filter with a reference light port matching photosensitivity. Using the plate specimen as the object, 0.6, 0.9, 1.2, and $1.5{\mu}m$ of out-plane deformation was made, and images were compared according to the difference in photosensitivity. After analysis, larger object deformations showed larger numbers of stripe patterns. Images became clearer and data error was reduced when the photosensitivity of object and reference light matched.

• Journal of ILASS-Korea
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• v.5 no.1
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• pp.5-12
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• 2000

The beneficial aspects of applying emulsion fuels to combustion systems may be due to the changes of fuel properties which lead to the enhanced atomization characteristics. The spray characteristics of water/oil emulsified fuel injected from the pressure-swirl(simplex) atomizer using for oil burner were investigated. Four different water contents from 10 to 40 % by volume at 10% increment were prepared by mixing with the different contents of surfactants. Total amount of surfactant used was varied from 1 to 3 % by volume. This study demonstrates the influence of water and surfactant contents of emulsified fuel, injection pressure on the spray characteristics, i.e. Sauter mean diameter(SMD) and spray angle. The drop size distribution of the emulsified fuel spray was measured with a Malvem particle sizer. In order to measure the spray angle, the digital image processing was employed by capturing multiple images of the spray with 3-CCD digital video camera. It was evident that the addition of water and surfactant changes fuel properties which are the key parameters influencing the atomization of the spray. The increase in surfactant content results in the decrease of SMD and the increase in spray angle. The droplets decease with increase in injection pressure, but the influence of injection pressure in this experimental condition was less important than expected. The more viscous fuel with the increase of water content exhibits the larger droplets in the centerline of the spray, and the less viscous fuel in the outer edges of the spray. The increase in axial position from the nozzle causes the spray angle to decrease. The spray angle decreases with increase in water content. This is due to increase in viscosity with increase in water content.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.382-387
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• 1992

In order to obtain desired arc welding performance, we already developed an arc welding robot system that enabled coordinated motions of dual arm robots. In this system one robot arm holds a welding target as a positioning device, and the other robot moves the welding torch. Concerning to such a dual arm robot system, the positioning accuracy of robots is one important problem, since nowadays conventional industrial robots unfortunately don't have enough absolute accuracy in position. In order to cope with this problem, our robot system employed teaching playback method, where absolute error are compensated by the operator's visual feedback. Due to this system, an ideal arc welding considering the posture of the welding target and the directions of the gravity has become possible. Another problem still remains, while we developed an original teaching method of the dual arm robots with coordinated motions. The problem is that manual teaching tasks are still tedious since they need fine movements with intensive attentions. Therefore, we developed a 3-dimensional vision guided robot control method for our welding robot system with coordinated motions. In this paper we show our 3-dimensional vision sensor to guide our arc welding robot system with coordinated motions. A sensing device is compactly designed and is mounted on the tip of the arc welding robot. The sensor detects the 3-dimensional shape of groove on the target work which needs to be weld. And the welding robot is controlled to trace the grooves with accuracy. The principle of the 3-dimensional measurement is depend on the slit-ray projection method. In order to realize a slit-ray projection method, two laser slit-ray projectors and one CCD TV camera are compactly mounted. Tactful image processing enabled 3-dimensional data processing without suffering from disturbance lights. The 3-dimensional information of the target groove is combined with the rough teaching data they are given by the operator in advance. Therefore, the teaching tasks are simplified

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.2
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• pp.37-42
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• 2008

Defects of corrugated board were limiting factors to the corrugated industry's growth. On-line detecting systems of defects are beneficial to increase profits of the corrugated board companies by reducing base paper consumption, increasing process reliability, and increasing productivity. By replacing naked eye inspection of defects to a defects detecting system, continuous inspection without fatigue may guarantee final products quality. The system was developed, which was consisted of line scan CCD camera, lens, illuminating parts, high speed image processor, software, various input parts, and output parts. First installation location of the system was at before fluting process after base paper unwinding, and surface of liner board was inspected by the system. Second installation location was after fluting process and combining process for liner board. Production loss includes ragged appearance of edge, irregular flute shape, wrong combination of flute, score cracking, defects in base paper, and flute cracking. The production loss was analyzed before and after the system installation at a commercial domestic mill. The production loss ratio was defined as a production loss weight per total production weight. The production loss ratio before the installation was decreased a lot from 1.28%(during 3 months before installation) to 0.76%(during 12 months after the first installation) and to 0.25%(during 6 months after the second installation).