• Title/Summary/Keyword: W-beam

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A study of characteristics for Image sticking in AC - Plasma Display Panel

  • Han, Yong-gyu;Lee, S.B.;Jeong, S.H.;Son, C.G.;Yoo, N.L.;Lee, H.J.;Lim, J.E.;Lee, J.H.;Jeoung, J.M.;Ko, B.D.;Oh, P.Y.;Moon, M.W.;Choi, Eun-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.263-265
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    • 2005
  • In the alternative current plasma display panel(AC-PDP) technology, it is very important to remove the image sticking for improving an image quality. In this paper, we have investigated the driving method of alternative current plasma display panel(AC-PDP) for preventing image sticking. We have investigated the driving method of alternative current plasma display panel(AC-PDP) for preventing image sticking. The preventing method of image sticking was proposed by adopting the Sticking Remove Pulse(SRP). The variation of brightness is most affected by the MgO to be formed at the surface of the phosphor layer. As a result, the image sticking is reduced when the driving method adopted an SRP.

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Automotive Adaptive Front Lighting Requiring Only On/Off Modulation of Multi-array LEDs

  • Lee, Jun Ho;Byeon, Jina;Go, Dong Jin;Park, Jong Ryul
    • Current Optics and Photonics
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    • v.1 no.3
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    • pp.207-213
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    • 2017
  • The Adaptive Front-lighting System (AFS) is a part of the active safety system, providing optimized vision to the driver during night time and other poor-sight conditions of the road by automatic adaptation of lighting to environmental and traffic conditions. Basically, an AFS provides four different modes of the passing beam as designated in an United Nations Economic Commission for Europe regulation (ECE324-R123): neutral state or country light (Class C), urban light (Class V), highway light (Class E), and adverse weather light (Class W). In this paper, we first present an optics design for an AFS system capable of producing the Class C/V/E/W patterns requiring only on/off modulation of multi-array LEDs with no need for any additional mechanical components. The AFS optics consists of two separated modules, cutoff and spread; the cutoff module lights a narrow central area with high luminous intensity, satisfying the cutoff regulation, and the spread module forms a wide spread beam of low luminous intensity. Each module consists of two major parts; the first converts a discretely positioned LED array into a full-filled area emitting light source plane, and the second projects the light source plane to a 25 m away target plane. With the combination of these two optics modules, the four beam patterns are formed by simple on/off modulation of multi-array LEDs. Then we report the development of a prototype that was demonstrated to provide the four beam patterns.

8 Beam Laser Diode Development for Laser Scanning Unit (Laser Scanning Unit을 위한 8빔 레이저 다이오드 개발)

  • Song, Dae-Gwon;Park, Jong-Keun;Kim, Jae-Gyu;Park, Jung-Hyun;So, Sang-Yang;Kwak, Yoon-Seok;Yang, Min-Sik;Choi, An-Sik;Kim, Tae-Kyung
    • Korean Journal of Optics and Photonics
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    • v.21 no.3
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    • pp.111-117
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    • 2010
  • A 780 nm monolithic individually addressable 8-beam diode laser with 10mW optical power was developed for use in a laser scanning unit. Beam to beam spacing is $30\;{\mu}m$ and an air bridge interconnection process was developed for individual operations. From electrical and optical characteristic measurements, the developed device is a suitable optical source for a high speed laser scanning unit in multi-function printing systems and laser beam printers.

Localization of Acoustic Sources on Wind Turbine by Using Beam-forming Techniques (빔-형성 기법을 이용한 풍력 터빈 음원의 국부화)

  • Lee, Gwang-Se;Shin, Su-Hyun;Cheong, Cheol-Ung;Jung, Sung-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.8
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    • pp.809-815
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    • 2009
  • The previous work(Cheong et al., 2006) where the characteristics of acoustic emissions of wind turbines has been investigated according to the methods of power regulation, has showed that the acoustic power of wind turbine using the stall control for power regulation is more correlated with the wind speed than that using the pitch control. In this paper, basically extending this work, the noise generation characteristics of large modern upwind wind turbines are experimentally indentified according to the power regulation methods. To investigate the noise generation mechanisms, the distribution of noise sources in the rotor plane is measured by using the beam-forming measurement system(B&K 7768, 7752, WA0890) consisting of 48 microphones. The array results for the 660 kW wind turbine show that all noise is produced during the downward movement of the blades. This result show good agreement with the theoretical result using the empirical formula with the parameters: the convective amplification; trailing edge noise directivity; flow-speed dependence. This agreement implies that the trailing edge noise is dominant over the whole frequency range of the noise from the 660 kW wind turbine using the pitch control for power regulation.

Effect of Laser Beam on Structural, Optical, and Electrical Properties of BaTiO3 Nanoparticles during Sol-Gel Preparation

  • Mostafa, Massaud;Ebnalwaled, Khaled;Saied, Hussien A.;Roshdy, Reham
    • Journal of the Korean Ceramic Society
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    • v.55 no.6
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    • pp.581-589
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    • 2018
  • This work concentrated on the effect of different laser beams on the microstructure and dielectric properties of $BaTiO_3$ nanoparticles at different calcinations times during the gelling preparation step. The nanoparticles were prepared by the sol-gel method. A green (1000 mW, 532 nm) and red laser beam (500 mW, 808 nm), were applied vertically at the center of stirring raw materials. The samples were sintered at $1000^{\circ}C$ for 2, 4, and 6 h. X-ray diffraction (XRD) analysis showed that samples prepared under the green laser have the highest purity. The FT-IR spectra showed that the stretching and bending vibrations of TiO bond without any other bonds, which are compatible to the X-ray diffraction (XRD) results. Samples were characterized by transmission electron microscopy (TEM), Scan electron microscopy (SEM), and UV-Visible spectrophotometer. Characterization showed the samples prepared under the green laser to have the highest particle size (~ 50 nm) and transparency for all sintering durations. Laser beam effects on electrical characterization were studied. BT nanoparticles prepared under the green laser show the higher dielectric constant, which was found to increase with sintering temperature.

Application of Laser Slit Beam to Characterize Yarn Irregularity

  • You Huh;Kim, Jong S.;Do W. Kwack;M.W. Suh
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.77-78
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    • 2003
  • The surface evenness and texture of textile products are closely related with the irregularity of yarn thickness which has an important role to influence the quality and the process efficiency. For measuring yam thickness the capacitive method is known to dominate the market, delivering results that are in a close relation with the mechanical properties of yarn, while the optical method offers information that seems related rather with the apparent quality of yarn. If a thin light beam is applied for the optoelectrical measurement, it is very possible that this method can provide us with important information which is not obtainable from the capacitive type measurement. This paper reports the results of a study about the yarn thickness and its variation on the basis of a new measurement system using a laser slit beam. Analysis of the new system confirms that we can extract new information on the yarn irregularity ranging into much short wavelengths. Even the visual shade created by the yam doubling and twisting can be measured and represented well. Depending on the yam types, the thickness measurements show their own characteristics.

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Localization of Acoustic Sources on Wind Turbine by Using Beam-forming Techniques (빔-형성 기법을 이용한 풍력 터빈 음원의 국부화)

  • Lee, Gwang-Se;Shin, Su-Hyun;Cheong, Cheol-Ung;Jung, Sung-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.04a
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    • pp.63-67
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    • 2009
  • The previous work (Cheong et al., 2006) where the characteristics of acoustic emissions of wind turbines has been investigated according to the methods of power regulation, has showed that the acoustic power of wind turbine using the stall control for power regulation is more correlated with the wind speed than that using the pitch control. In this paper, basically extending this work, the noise generation characteristics of large modern upwind wind turbines are experimentally indentified according to the power regulation methods. To investigate the noise generation mechanisms, the distribution of noise sources in the rotor plane is measured by using the Beam-forming measurement system (B&K 7768, 7752, WA0890) consisting of 48 microphones. The array results for the 660 kW wind turbine show that all noise is produced during the downward movement of the blades. This result show good agreement with the theoretical result using the empirical formula with the parameters: the convective amplification; trailing edge noise directivity; flow-speed dependence. This agreement implies that the trailing edge noise is dominant over the whole frequency range of the noise from the 660 kW wind turbine using the pitch control for power regulation.

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Reliability analysis of simply supported beam using GRNN, ELM and GPR

  • Jagan, J;Samui, Pijush;Kim, Dookie
    • Structural Engineering and Mechanics
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    • v.71 no.6
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    • pp.739-749
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    • 2019
  • This article deals with the application of reliability analysis for determining the safety of simply supported beam under the uniformly distributed load. The uncertainties of the existing methods were taken into account and hence reliability analysis has been adopted. To accomplish this aim, Generalized Regression Neural Network (GRNN), Extreme Learning Machine (ELM) and Gaussian Process Regression (GPR) models are developed. Reliability analysis is the probabilistic style to determine the possibility of failure free operation of a structure. The application of probabilistic mathematics into the quantitative aspects of a structure and improve the qualitative aspects of a structure. In order to construct the GRNN, ELM and GPR models, the dataset contains Modulus of Elasticity (E), Load intensity (w) and performance function (${\delta}$) in which E and w are inputs and ${\delta}$ is the output. The achievement of the developed models was weighed by various statistical parameters; one among the most primitive parameter is Coefficient of Determination ($R^2$) which has 0.998 for training and 0.989 for testing. The GRNN outperforms the other ELM and GPR models. Other different statistical computations have been carried out, which speaks out the errors and prediction performance in order to justify the capability of the developed models.

The Effect of Cross Beam on the strength and Stiffness of the Frame in Shuttle Car for LMIT (LMTT용 Suhttle Car의 Frame 강도 및 강성에 미치는 Cross Beam의 영향)

  • Lim J. H.;Han G. J.;Lee K. S.;Han D. S.;Shim J. J.;Lee S. W.;Jeon Y. H.
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.11a
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    • pp.323-328
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    • 2004
  • According as the quantity of goods transported by ship is increasing about $7\%$ per year, a port environment is rapidly changing. To meet this situation successfully, the development of the next generation port loading and unloading system (LMTT) is studied. A Frame of shuttle car for LMTT(Linear Motor-based Transfer Technology) consist of three parts which are outer beam inner beam and cross boom. Outer boom supports a container and inner boom is a framework and cross boom reinforces outer and inner boom. In this study, we carried out the finite element analysis for the effect of cross boom on the strength and stiffness qf the frame according to the number if cross beam leading position of container, the distance ratio if inner boom from center.

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6MV Photon Beam Commissioning in Varian 2300C/D with BEAM/EGS4 Monte Carlo Code

  • Kim, Sangroh;Jason W. Sohn;Cho, Byung-Chul;Suh, Tae-Suk;Choe, Bo-Yong;Lee, Hyoung-Koo
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.113-115
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    • 2002
  • The Monte Carlo simulation method is a numerical solution to a problem that models objects interacting with other objects or their environment based upon simple object-object or object-environment relationships. In spite of its great accuracy, It was turned away because of long calculation time to simulate a model. But, it is used to simulate a linear accelerator frequently with the advance of computer technology. To simulate linear accelerator in Monte Carlo simulations, there are many parameters needed to input to Monte Carlo code. These data can be supported by a linear accelerator manufacturer. Although the model of a linear accelerator is the same, a different characteristic property can be found. Thus, we performed a commissioning process of 6MV photon beam in Varian 2300C/D model with BEAM/EGS4 Monte Carlo code. The head geometry data were put into BEAM/EGS4 data. The mean energy and energy spread of the electron beam incident on the target were varied to match Monte Carlo simulations to measurements. TLDs (thermoluminescent dosimeter) and radiochromic films were employed to measure the absorbed dose in a water phantom. Beam profile was obtained in 40cm${\times}$40cm field size and Depth dose was in 10cm${\times}$10cm. At first, we compared the depth dose between measurements and Monte Carlo simulations varying the mean energy of an incident electron beam. Then, we compared the beam profile with adjusting the beam radius of the incident electron beam in Monte Carlo simulation. The results were found that the optimal mean energy was 6MV and beam radius of 0.1mm was well matched to measurements.

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