• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.424-432
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• 2007

Luminance properties of external electrode fluorescent lamps and optical components in backlight unit (BLU) and optical transmission rates of optical sheets, are investigated for LCD-TV of 32" in diagonal with WXGA level resolution (1366$\times$768). The luminance is measured in 12-lamps and 18-lamps of BLU. The luminance uniformity preserves about 85 % in the 12-lamps backlight, while the luminance of optical components and the efficiency of backlight in the 12-lamps are lower than those in the 18-lamps backlight. When the lamp luminance in BLU having 12-lamps and 18-lamps is normalized as 100 %, the relative luminance of a diffusion plate, a diffusion sheet, a prism sheet (BEF), a polarization sheet (DBEF), has a constant value without dependence on a lamp luminance. The relative luminance of optical components in 12-lamps BLU is lower than that in 18-lamps backlight. The light transmission rate, the relative luminance of liquid crystal display panel with the luminance 100 % of backlight, is 7.14 % in the use of DBEF and BEF, 6.12 % in the use of only DBEF, and 3.21 % in the use of only BEF. Those Data obtained in this experiment for the lamps and optical components, are the design parameters for the LCD backlight.

• Journal of Korean Living Environment System
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• v.20 no.2
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• pp.233-237
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• 2013

Daylighting affects the luminous environment and provides comfortable environment to the occupants. However, excessive daylighting might have negative influences on the visual comfort. Skylight, light intensity and distribution, and insolation could cause glare effects on the occupants. This study analyzed the effect of fenestration on the interior glare effects, and verified luminous environment adjustability through mock up test of conventional fenestration and 'Convergence Window System' by analyzation of luminance, luminance contrast, and glare effect. Consequently, room installed Convergence Window System was improved luminance contrast and PGSV Level.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.1
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• pp.1-9
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• 2015

This paper introduces the development of imaging luminance meter which measures the luminances of external/internal road tunnel. The developed imaging luminance meter complies with both L20 method and Veiling luminance method of the international standards, CIE88. In this paper the L20 method is mainly presented because most of tunnels currently adapt L20 method. The developed system has an embedded computer to operate at stand-alone. The system has a ethernet port, a heater, a fan, a defroster, a wiper and sun shielder. Compensation algorithm is applied for correcting non-linear responses to the luminance and integration time. The accuracy of measurement is less than 1% when it calibrated at the public certification institute. The developed system was also tested at the real field, road tunnel. The test results were very similar with the reference luminance meter and showed that the developed system operates well at the real field. Partial sensor saturations were happened to show the less luminance, because there were the high reflecting objects in the real field. Further study should be followed for high luminance measurement.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.17-21
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• 2001

We analyzed the luminance in the visual light region and the size of pupil by the luminance to estimate an UV-A line cut efficiency in the lens. The size of pupil by the luminance(L) was given by ${\Phi}=d-e{\cdot}tanh(f{\cdot}logL)$ and the transmittance efficiency value of a size of pupil was given by $T_r(r)=1-gr^2+hr^4$. We derived the absolute cut efficiency value ${\alpha}$ and the exclusion index $b=(1-{\alpha}){\times}100%$ about the UV-A in the $320{\sim}400nm$ regions. The ${\alpha}$ and b values were obtained respectively 0.018, 0.31, 0.273, 0.153 and 98, 69, 72, 85% of Uv-cut Lens, CR-39, red color and blue color.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.43-48
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• 2000

It was to adjust the luminance of light by the rotation angle of the polarizes and analyzer. The luminance value Lmax, Lmin of Contrast Sensitivity could be obtained from the rotation angle ${\theta}_m$ of the average luminance($L_m$), the rotation angle(${\theta}_{max}$, ${\theta}_{min}$) of the maximum and the minimum's amplitude. $$L_{max}=I(0)e^{-2at}{\cdot}cos^2{\theta}_m(1+C_s^{-1})$$ $$L_{min}=I(0)e^{-2at}{\cdot}cos^2{\theta}_m(1-C_s^{-1})$$ We obtained the rotation angle(${\theta}_{max}$, ${\theta}_{min}$) of the polarizes and analyzer from the rotation angle ${\theta}_m$ of the average luminance($L_m$) and the Contrast Sensitivity($C_s$). $${\theta}_{max}=cos^{-1}[cos{\theta}_m{\cdot}(1+C_s^{-1})^{1/2}]$$ $${\theta}_{min}=cos^{-1}[cos{\theta}_m{\cdot}(1-C_s^{-1})^{1/2}]$$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.14-19
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• 2013

Tunnel lighting design and operation are both regulated based on luminance in and out of Korea these days. However, domestic tunnel lighting is operated by internal lighting depending on external brightness by using an illuminometer applying the conversion factor on luminance. The purpose of tunnel lighting is to alleviate the visual shock occurring from the rapid change from external brightness to internal brightness when entering a tunnel. However, when looking at the tunnels operated based on an illuminometer, it is not a system where the driver can measure the brightness within his or her viewing angle when entering the tunnel. It is general to install and operate the illuminometer on the roof of an administrative office near the tunnel; however, this method is not structured to connect with the internal lighting by checking the brightness of the viewing scope of the driver, thus is not structured to properly apply the viewing conditions of the driver. Rather, it should be in a method for extracting the luminance value within the viewing scope of the driver pursuant to tunnel lighting standards and in connection with internal lighting. This research seeks to find the difference between operations based on luminance and operations based on intensity of Illuminance in road tunnels through field measuring, and to suggest the necessity of operating based on luminance with the resulting value.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.5
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• pp.382-388
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• 2016

When Flat Panel Display (FPD) is made with backlight module, such as LED TV, it inherently suffers from the non-uniform backlight luminance problem that results in un-even brightness distribution throughout the TV screen. If the luminance of each pixel location of a TV screen as a function of the driving voltage can be measured, it can be used to compensate the non-uniformity of the backlight module. We use a carefully calibrated imaging system to take pictures of a TV screen at different levels of brightness and generate the compensation functions for the driving circuitry to correct the luminance level at each pixel location. Making use of the fact that the luminance of the screen is normally brightest at around the center of the screen and gradually decreases toward the border of the screen, the luminance of the whole TV screen is approximated by a mathematical function of the pixel locations. The parameters of the function are computed in the least square sense by the values of both the pixel luminance sent from the driving circuit and the grayscale value measured from the image taken by the imaging system. To justify the correction system, a simple second order polynomial function is used to approximate the luminance across the screen. When the driving circuit voltage is corrected according to the measured function, the variance of the screen luminance is reduced to one tenth of the one measured from the un-corrected TV screen.

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.67-73
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• 2015

PURPOSES : This study was conducted to derive the optimum mixing ratio of phosphorescent pigment for the development of phosphorescent line marking. METHODS: In this study, we utilized a literature review and case study methodology, to describe the domestic and foreign state of practice for the production and mixing of phosphorescent pigment for use in line marking. The optimal mixing ratio was derived by comparing the reduction in luminance over time for the various phosphorescent pigment mixing ratios identified in the literature. In addition, performance and construction characteristics were analyzed using field testing techniques. RESULTS : The results were as follows: 1) the results of the luminance performance standards tests showed that all of the phosphorescence test specimens satisfied the phosphorescent fire protection standard. As the phosphorescent pigment mixing ratio increased, the luminance value increased, 2) the luminance reduction rate was minimum at the mixing ratio of 50%. However, when compared to a mixing ratio 40%, a small difference was recorded, the luminance reduction rate from the mixing ratio of 40% is judged as being converged. Therefore, in view of the economic efficiency, it was determined that the optimal mixing ratio was 40%, 3) as a result of construction on the field, a mixing ratio of 40% was found to have a higher luminance value than the general line marking for up to three hours after sunset, 4) it was found that the phosphorescent line markings without glass beads spraying had a higher luminance value than the phosphorescent line markings with glass beads spraying. CONCLUSIONS : Through the results of the basic experiments of the line markings obtained by blending a phosphorescent pigment, the results could be applied to play an important role in the development of phosphorescent line marking paint technology and in establishing application planning for on-site construction characteristics.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.92-98
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• 2003

The quantification of fish school abundance was carried out by using luminance of pixel on scanning sonar image, and compared with the indices of fish school abundance e.g. school number, school area and weighted school area. The survey was carried out in Funka Bay off southern Hokkaido, Japan using research vessel Ushio-Maru during December 1999. A 180-degree scanning sonar with a frequency of 164kHz was used. The school number was counted both left and right 40-degree radial lines from the center of own vessel mark on a scanning image. The school area was measured approximately as an ellipse from the school length and width. The weighted school area was calculated by multiplying school area and average value of inner pixel luminance. A quantification of pixel luminance was also measured to integrate squared pixel luminance value on these lines. Fish school and school bottom were discriminated by the produced sonar echogram using pixel luminance value on these lines. The relationships between the quantified luminance value and other abundance indices such as school area and weighted school area revealed a good correlation. Therefore, the quantified luminance is a useful method in estimating fish school abundance in the acoustic survey using sonar.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.6
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• pp.1-8
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• 2006

The study is to analyze the surface luminance of the illuminated bridges according to the change of view point using luminance measurements with instrument CS-100 and ProMetric 1400. For the purpose the illuminated bridges of the structure type were sleceted. Also, the view points were classified the three types which are a perspective view, a building view, a driver view. The luminance of the surrounding sky, surface of river, upper structure or bridge, girder side, and pier or the objects was measured. As a result of this study, The Kwangjin and Dongho Bridge showed the luminance distribution of a perspective view was high. And the Olympic and Dongjac bridge the luminance distribution of building view was high. The luminance effect of the girder bridge that has no upper structure was distinguished for the perspective view, and the cable-stayed girder bridge and the arch bridge were characterized as the building view.