• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.615-618
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• 2009

In order to apply for transparent conductive oxide(TCO), we deposited ZnO thin film on the glass at room temperature by RF magnetron sputtering method. Deposition conditions for low resistivity were optimized in our previous studies. Under the deposition condition with the RF power of 800 [W]. Sheet resistance and surface roughness of ITO and ZnO thin film were measured by Hall-effect measurement system and AFM, respectively. The sheet resistance of ITO and ZnO thin film were 7.290 [$\Omega$] and 4.882 [$\Omega$], respectively. and surface roughness were 3.634 [nm] and 0.491 [nm], respectively. Green OLED was fabricated with the structure of TPD(400 [$\AA$])/Alq3(600 [$\AA$])/LiF(5 [$\AA$])/Al(1200 [$\AA$]). Turn-on voltage of green OLED applied ITO was 7 [V] and luminance was 7,371 [$cd/m^2$]. And, Turn-on voltage of green OLED applied ZnO was 14 [V] and luminance was 6,332 [$cd/m^2$].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.1
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• pp.81-85
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• 2009

We has been analysed optical properties of OLED(organic light emitting diode) and characteristics of ITO(Indium Tin Oxide) in terms of $O_2$ plasma treatment for manufacturing high efficiency OLED, RF power of $O_2$ plasma was changed 25, 50, 100, 200 W. $O_2$ gas flow, gas pressure and treatment time were fixed. Sheet resistance and surface roughness of ITO were measured by Hall-effect measurement system and AFM, respectively. The ranges of sheet resistance and surface roughness were $5.5{\sim}6,06\;{\Omega}$ and $2.438{\sim}3.506\;nm$ changing of RF power, respectively, PM(Passive Matrix)OLED was fabricated with the structure of ITO(plasm treatment)/TPD($400\;{\AA}$)/$Alq_3(600\;{\AA})$/LiF($5\;{\AA}$)/Al($1200\;{\AA}$). Turn-on voltage of PMOLED was 7 V and luminance was $7,371\;cd/m^2$ at the RF power of 25 W, $O_2$ plasma treatment of ITO surface was result in lowering the operating voltage and improving luminance of PMOLED.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.54-55
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• 2006

Organic light-emitting diodes(OLEOs) are attractive because of possible application in display with low operating voltage, low power consumption, self-emission and capability of multicolor emission by the selection of emissive material. We investigated the effects of deposition rate on the electrical characteristics, physical characteristics and optical characteristics of OLEOs in the ITO(indium-tin-oxide)/N.N'-diphenyl-N,N'-bis(3-methyphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/tris(8-hydroxyquinoline)aluminum($Alq_3$)/Al device. We measured current density, luminous flux and luminance characteristics of devices with varying deposition rates of TPD and $Alq_3$. It has been found that optimal deposition rate of TPD and $Alq_3$ were respectively $1.5{\AA}/s$ from the device structure. An AFM measurement results, surface roughness of the deposited film was the lowest when deposition rate was $1.5{\AA}/s$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.1-10
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• 2007

KH University has developed a large sky simulator which is its scale suits international standard. To verify the reliability of the sky simulator, the luminance of 36 points on the inner sky surface was measured and compared with the CIE standard overcast sky model. It was found that the sky simulator can reproduce the CIE standard overcast sky condition with 1.8[%] of mean difference. To identify the differences of daylighting performance, scale model measurements were taken under a real sky and in a sky simulator. Under overcast sky conditions, two kinds of scale model experiments were conducted by using the photometric sensor Li-cor. Firstly, a 1/20 scale model of a side-lit office room 4.9[m] wide, 7.2[m] long, and 2.6[m] high was created. Five measurement points were set at 1.2[m], 2.4[m], 3.6[m], 4.8[m], and 6.0[m] from the window. The mean difference of the light factor between the sky simulator and real sky was 7.1[%]. Secondly, a 1/30 scale model of a top-lit atrium 15[m] wide, 15[m] long, and 15[m] high was created. The measurement point was set at center of the room and the well indexes of the model were set in 5 types. The mean difference of the light factor between the sky simulator and real sky was 1.7[%]. This proved that the sky simulator is fully accurate and usable for daylighting research.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.5
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• pp.203-211
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• 2002

In this paper, the implementation of a new AF(Automatic Focusing) system for a digital still camera is introduced. The proposed system operates in real-time while adjusting focus after the measurement of distance to an object using a passive sensor, which is different from a typical method. In audition, measurement errors were minimized by using the data acquired empirically, and the optimal measuring time was obtained using EV(Exposure Value) which is calculated from CCD luminance signal. Moreover, this system adopted an auxiliary light source for focusing in absolute dark conditions, which is very hard for CCD image Processing. Since this is an open-loop system adjusting focus immediately after the distance measurement, it guarantees real-time operation. The performance of this new AF system was verified by comparing the focusing value curve obtained from AF experiment with the one from the measurement by MF(Manual-Focusing). In both case, edge detector was used for various objects and backgrounds.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.4
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• pp.190-196
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• 2001

We measured 3-dimensional images of the light emitted from plasma display panel(PDP) by using newly proposed scanned point detecting method(SPDM). The SPDM has the point detector with pinhole. The light emitted from PDP cell at the in-focus position can pass through the pinhole and be collected by detector. On the contrary, the light emitted from PDP cell at the out-of-focus positions is focused on the front of or the behind of the pinhole. We could analyze the characteristic of 3-dimensional light emission distribution by SPDM. From 3-dimensional measurement of 828[nm], the efficient design of PDP cell, the importance of opening ration, and the relations between BUS electrode position and discharge intensity are obtained. Also, the relationship between discharge characteristics and sustain electrode structures in AC-PDP are studied by measuring luminance, current, and discharge voltage.

• Current Optics and Photonics
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• v.8 no.3
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• pp.307-312
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• 2024

Measuring the three-dimensional (3D) spatial light intensity distribution of an autostereoscopic multiview 3D display at the user position is time-consuming, as luminance has to be measured at different positions around the user position. This study investigates a method to quickly estimate the 3D distribution at the user position. For this purpose, a measurement setup using a white semitransparent diffusing screen or a two-dimensional (2D) spatial sensor was devised to measure the 2D light intensity distribution at the user position. Furthermore, the 3D spatial light intensity distribution at the user position was estimated from these 2D distributions at different viewing distances. From the estimated 3D distribution, the characteristics of autostereoscopic 3D display performance can be derived and the candidate positions for further accurate measurement can be quickly determined.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.16-26
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• 2004

As the importance of outdoor lighting become more widely recognized, outdoor lighting has been installed in many buildings, plazas, landscape, and historical monuments in Korea, Outdoor lighting on showing complex, in particular, express its values as local landmarks. However, the excessive outdoor lighting in the large-scale shopping complex tends to cause light pollution. Many advanced countries are trying to create a comfortable lighting environment by the guidlines and regulations on outdoor lighting to prevent light pollution. For this research backgrounds, the light pollution of three showing complexes in Seoul have been investigated. For the purpose, luminance of building facade, horizontal illuminance, and vertical illuminance were measured with proper measurement instruments and compared the results with the CIE recommendations. The results of the study are as follows. As no cut-off luminaries are currently installed on pedestrian walks, some glare were occured partially. It also shows that the luminance of building facades are high to improve the degree of public awareness of buildings and advertisements. In other words, the luminance of the building facade, when compared with that of the CIE recommendations, is twice as high and the vatical illuminance of pedestrian walks is far higher than that of the CIE recommendations, which proves the existence of light pollution. As Korea has not yet provided proper regulations or guidelines for the control of light pollution, it is necessary to make appropriate codes for it.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.3-6
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• 2015

Recently, the collection of the sensor data and its analysis become important as the smart buildings equipped with the various sensors appear as a usual scene. The interconnection through the wire cable among the sensors is indispensible because of the information collections such as the temperature, the humidity, and the luminance in the rooms and the hallways for the effective management of the in-building energies. However, these interconnections through the cabling will be very costly, time-consuming, and a difficult task since they will cause some damages to the buildings. Therefore, the interconnections through the unwired connections are required in terms of the deployment effectiveness such as time and cost In this paper, the design and the operation appropriateness are confirmed through the simulation of the signal measurement system for in-building propagation characteristics based on signature sequence.

• Journal of Information Display
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• v.11 no.1
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• pp.17-20
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• 2010

With the increasing demand for a better FPD image quality, better evaluation metrics and advanced display quality measurement methods are required to meet these needs. There are many measurement methods for evaluating the viewing angle of various display devices, but these methods, which include luminance drop, color shift, and contrast ratio decrease, are imperfect considering that human perception does not completely correlate to them. In this paper, a new method of measuring the perceptual angle of FPDs is proposed, considering human visual perception, which uses the color space of the color appearance model.