• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.149-163
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• 1994

A novel method of dimensional measurement using machine vision, which is called Landmark Tracking System, has been developed. Its advantages come form tracking only the bright, standard shaped "landmarks" which are made from retroreflective sheets. In the design of the LTS, it is essential to know the relationship between optical parameters and their influence on system performance. Such optical parameters include the brightness of landmark image, the illumination system design, and the choice of imaging optics. And the performance of retroreflective material also plays important role in the LTS performances. Influences of such optical parameters on LTS's dimensional measurement characteristics are investigated, with respect to the retroreflective material, the imaging optics, and the illumination system. Measuremtn errors due to parameter variations are also analyzed. Experiments are performed with a LTS prototype. Retroreflective characteristics are verified, and the LTS's measurement performances are measured in the form of repeatability and accuracy. Experimental results shgow that the LTS has repeatability better than 1/30,000 of a field of view(30 degrees), and accuracy better tha 1/3,000 of a field fo view.d fo view.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1822-1829
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• 2015

In this study, artificial neural networks were used to determine the intensity of brightness in interior spaces. The illumination elements to illuminate indoor spaces were considered, not individually, but as a system. So, during the planned maintenance periods of an illumination system, after its design and installation, simple brightness level measurements must be taken. For a three-dimensional evaluation of the brightness level in indoor spaces in a speedy and accurate manner, the obtained brightness level measurement results and artificial neural network model were used. Upon estimation of the most suitable brightness level for indoor spaces by using the artificial neutral network model, the energy demands required by the illumination elements decreased. Consequently, in this study, with estimations of brightness levels, the extent to which the artificial neutral networks become successful was observed and more correct results have been obtained in terms of both economy and usage.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1402-1406
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• 2004

As a method of confirming light flickering, we tried to confirm the flicker index measured by Flickermeter and the application possibility by using digital intensity of illumination meter. Also, after simulating the quality deterioration of electric power and generating a various voltage change, we studied on the function between the flicker index measured by Flickermeter and the flicker index for the intensity of illumination by using digital intensity of illumination meter.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.91-109
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• 1991

The purpose of this study were to comfirm the effects of the thickness and kinds of porcelain, etchants, illumination time, elapsed time for the measurement, and chemical cure component to the bond strength of porcelain laminate and composite resin cement, and to compare the effects between the light cured resin and the dual cured resins. The etched porcelain surface, the sectioned surface crossing porcelain and resin after bonding, and the debonded surfaces were observed by the SEM. One product of laminate porcelain powder, one light cured resin and two dual cured resins were selected. Each resin cements are lightened through the thin porcelain disc which was cut from cylindrical porcelain specimen by the diamond saw, and by the light through the porcelain disc they were bonded. Changes of thickness and kinds of porcelain, etchants, illumination time, and the elapsed time for the measurement were considered as variables for the bond strength. And the bond strength of porcelain and dual cured resins under the conditions of autopolymerization or the removal of chemical cure component were measured and compared. Bond strength were measured by shear stress. The etched surface, the cross-sectioned surface, and the debonded surface of porcelain or resin were observed by SEM. On the summary of this study, the following conclusions can be stated; 1. Bond strength of light cured resin was decreased inversely by the thickened porcelain laminate and showed the lowest value to the masking dentin porcelain among 4 kinds of porcelain powder. 2. Bond strength of autopolymerization of dual cured resin without illumination in dark chamber were from 75% to 98% to the data of dual cured resin with illumination. 3. Bond strength of dual cured resin used without chemical cured components were same to them of light cured resin. 4. Cross-sectioned surface treated by silane did not show the gap between the porcelain and resin. 5. Illumination over 80 seconds did not make the significant increase of bond strength on all kinds of resin.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.172-177
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• 1998

For making high-functional illumination environment and pleasantness to human beings, it is needed to analyze optical characteristics from lightsource as well as to analyze and examine emotional characteristics which respond to optical characteristics systematically. Also, it is Possible to classify lightsource according to function and use based on optical and emotional characteristics systematically and these results can be applied to practical data for professional illumination design field. The aim of this study is to develop technique for evaluating sensibility as well as to accumulate sensibility database through measuring and evaluating emotional reaction to optical characteristics from lightsource. Final aim of this study is to develop simulation and evaluation technique for interior illumination environment, the outline of this paper : 1) operating simulator for various illumination environment 2) developing evaluation methodology for evaluating illumination environment 3) preparing sensibility index through evaluation and analysis The process of this study is as follows. 1) Developing optical evaluation item of lightsource 2) Developing emotional evaluation item of lightsource 3). Analyzing, correlation between optical evaluation item and emotional eveluation item 4) Classifying and selecting object for evaluation 5) Optical measuring and evaluating for lightsource 6) Operating Simulator for illumination environment 7) Emontional measuring and evaluating lightsource and color 8) Developing estimative formula and sensibility index of emotional reaction The results of this study are as follows. 1. Simulator is operated for various illumination environment, and it is proved to be applicable to actual environment. 2. Evaluation and Analysis Techniques is developed for emotional measurement about illumination environment. 3. Estimative formula and sensibility index are prepared, which can estimate the characteristic of lightsource and emotional reaction to interior color

• The Magazine for Energy Service Companies
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• s.10
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• pp.38-42
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• 2001

• The Magazine for Energy Service Companies
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• s.9
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• pp.42-47
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• 2001

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.6
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• pp.14-23
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• 2009

The actual conditions of school illumination was investigated. The illumination state was classified by the number of installed luminaires per 1 classroom. The illuminance was measured and analyzed. The work surface illuminance was up to the standard, but the illuminance on blackboard was below standard when there was no local lighting. As a result of conducting a simulation based on the measurement of the reflection factors of the classroom finishing materials and lamp replacement and lamp cleaning, nine luminaires for general lighting and local lighting for the blackboard were required, and a design considering illumination maintenance was called for.

• Journal of the Optical Society of Korea
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• v.15 no.1
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• pp.38-43
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• 2011

We have developed a simple model of a bright-room contrast ratio (BRCR) measurement system for plasma display panels (PDPs) adopting a contrast enhancement film (CEF) by using an illumination design tool. Only four model parameters were used, namely, total ambient illumination power delivered by fluorescent lamps, a panel scattering rate, illuminance of PDP white patterns, and the absorption coefficient of a color adjusting film. These parameters were determined by simple optical measurements and matching simulations. The proposed model was employed to predict the BRCR values of four different CEF samples, and the simulated ones were found to be in agreement with measured ones within about 10% relative-error.

• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.746-754
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• 2008

This paper proposes a method to detect calibration patterns for accurate camera calibration under complicated backgrounds and uneven lighting conditions of industrial fields. Required to measure object dimensions, the preprocessing of camera calibration must be able to extract calibration points from a calibration pattern. However, industrial fields for visual inspection rarely provide the proper lighting conditions for camera calibration of a measurement system. In this paper, a probabilistic criterion is proposed to detect a local set of calibration points, which would guide the extraction of other calibration points in a cluttered background under irregular lighting conditions. If only a local part of the calibration pattern can be seen, input data can be extracted for camera calibration. In an experiment using real images, we verified that the method can be applied to camera calibration for poor quality images obtained under uneven illumination and cluttered background.