• Title/Summary/Keyword: High brightness

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Physical Characteristics of Small Space Objects at High Orbits Based on Optical Methods

  • El-Hameed, Afaf M. Abd;Attia, Gamal F.;Abdel-Aziz, Yehia
    • Journal of Astronomy and Space Sciences
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    • v.34 no.1
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    • pp.31-35
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    • 2017
  • Optical observation is one of the most common techniques used for characterizing the physical properties of unknown objects and debris in space. This research presents measurements and properties of the new object 96019 from ground-based optical methods. Optical observations of this small object were performed using a charge-coupled device (CCD) camera and the Santel-500 telescope at the Zvenigorod Observatory. The orbital elements and physical properties of this object, such as area-to-mass ratio, have been determined. The results show that this small object has a low area-to-mass ratio, between 0.009 and $0.12m^2/kg$. The light curve of object 96019 is given: Over the time intervals, variations in brightness are analyzed and the maximum brightness was found to be 12.4 magnitudes. The observational results show that, this object brightens by about three magnitudes over a time span of three minutes. Based on these observations, the characteristics and physical properties of this object are discussed.

Analysis of back "mura" in prism light guide plate for high brightness LCD's (고휘도용 프리즘 도광판의 암선연구)

  • Oh, Young-Sik;Yoon, Dae-Keun;Bae, Kyung-Woon;Kim, Youn-Ho;Lim, Young-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05a
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    • pp.165-168
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    • 2004
  • We have analyzed the cause of black "mura" and measured it in prism light-guide plate (LGP). Properties of components used in a back light. unit (BLU) have changed by Simulation Tool. We get major factor of black "mura" for improvement in prism LGP. For the improvement of black "mura", removal of brightness "mura" at input light part must precede preferentially because of reflection characteristics of the prism LGP. Removal of brightness "mura" is improved by changing of input light part in LGP and dispersion treatment.

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A Dual In-Plane Electrode Structure for Better Brightness in a Helix-Deformed FLCD

  • You, Doo-Hwan;Lee, Sin-Doo;Lee, Ju-Hyun;Na, Do-Jun
    • Journal of Information Display
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    • v.2 no.1
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    • pp.1-4
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    • 2001
  • We propose a dual in-plane parallel electrode structure of a vertical configuration of a helix-deformed ferroelectric liquid crystal (HDFLC) mode for better brightness than a single in-plain electrode case. This structure provides high brightness in addition to the analog gray scale capability, fast response, and wide-viewing characteristics. In contrast to a conventional HDFLC in a planar geometry, smectic layers arrange themselves parallel to the substrates and thus extremely uniform alignment of molecules in a large area is naturally achieved in our new configuration.

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3D Image Representation Using Color Correction Matrix According to the CCT of a Display (디스플레이 상관 색온도에 따른 색 보정 매트릭스를 이용한 3D 영상 재생)

  • Song, Inho;Kwon, Hyuk-Ju;Kim, Tae-Kyu;Lee, Sung-Hak
    • Journal of Korea Multimedia Society
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    • v.22 no.1
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    • pp.55-61
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    • 2019
  • Almost all 3D displays have a brightness reduction in the 3D mode comparing to the 2D mode. When the brightness is reduced, one of the color attributes, the colorfulness, is decreased. In this case, the viewer feels that the image quality is deteriorated. In this paper, we proposed a method to compensate for the degradation of colorfulness due to brightness reduction in 3D mode for high quality 3D image viewing using the CIECAM02 model and the color correction matrix. As a result of applying the proposed method, we can confirm that the colorfulness is improved in 3D mode.

Single-Image Dehazing based on Scene Brightness for Perspective Preservation

  • Young-Su Chung;Nam-Ho Kim
    • Journal of information and communication convergence engineering
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    • v.22 no.1
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    • pp.70-79
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    • 2024
  • Bad weather conditions such as haze lead to a significant lack of visibility in images, which can affect the functioning and reliability of image processing systems. Accordingly, various single-image dehazing (SID) methods have recently been proposed. Existing SID methods have introduced effective visibility improvement algorithms, but they do not reflect the image's perspective, and thus have limitations that distort the sky area and nearby objects. This study proposes a new SID method that reflects the sense of space by defining the correlation between image brightness and haze. The proposed method defines the haze intensity by calculating the airlight brightness deviation and sets the weight factor of the depth map by classifying images based on the defined haze intensity into images with a large sense of space, images with high intensity, and general images. Consequently, it emphasizes the contrast of nearby images where haze is present and naturally smooths the sky region to preserve the image's perspective.

Characterizations of Luminance for Varied LED Based Surface Lighting Designs (LED 면광원에서 패키지 수량에 따른 휘도변화 특성)

  • Lee, Tae-Hoon;Choi, Seong-Dae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.6
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    • pp.70-76
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    • 2016
  • Commercialization of surface lighting using Light Emitting Diodes (LED) has embraced the advance to Organic Light Emitting Diode (OLED) technology. This is necessary to achieve light-efficiency-improvement and longer component life. The range of application of LED lighting for both interior and outdoor lights has been gradually expanding. Automobiles and home appliances are now included. In the case of LED surface lighting in a domestic refrigerator, achieving high efficiency requires optimization of the number of LEDs in a pack. Optimization is also required in the design stage of development with regard to the conversion of the light source type from point light sources to the surface light type. This paper addresses these design problems. It presents a study of brightness variations for design solutions that differ from the existing technology in both the number of LED packages and use of Light Gathering Power (LGP) information. The intention is to facilitate production of high brightness LED surface lighting for domestic refrigerators.

Lyman-alpha radiative transfer through outflowing halo models to understand both the observed spectra and surface brightness profiles of Lyman-alpha halos around high-z star-forming galaxies

  • Song, Hyunmi;Seon, Kwang-il
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.59.3-59.3
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    • 2018
  • With a recent observational study of extended Lyman-alpha halos around individual high-z star-forming galaxies by Leclercq et al. (2017) using MUSE, we perform radiative transfer calculations to see if Lyman-alpha scattering can explain the spatial extents of the halos together with their spectra. We adopt a spherically-symmetric halo model in which Lyman-alpha sources and neutral hydrogen (HI) medium have exponential density distributions. The HI medium is set to have outflowing motion based on a momentum-driven wind scenario in a gravitational potential well. We run our Lyman-alpha radiative transfer code, LaRT, upon this halo model for various sets of parameters regarding the HI medium such as temperature, optical depth, density scale radius, outflow velocities, and dust content. We analyze simulation results to see the impact of each parameter on Lyman-alpha spectra and surface brightness profiles, and degeneracies between the parameters. We also find a parameter set that best reproduces simultaneously the observed spectra and surface brightness profiles of the MUSE Lyman-alpha halos.

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Brightness Property by Applied Frequency for External Electrode Fluorescent Lamp (EEFL) (External Electrode Fluorescent Lamp (EEFL)의 입력 주파수에 따른 휘도특성)

  • Lee, Seonh-Jin;Yang, Jong-Kyong;Choi, Yong-Sung;Lee, Sang-Hern;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2005.11a
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    • pp.223-225
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    • 2005
  • An external electrode fluorescent lamps (EEFLs) have the advantage of a long lifetime in the early stages of the study on plasma discharge, interest in the lamp continues. Studies on the operation of external electrode fluorescent lamps have focused mainly on its use of a type of high frequency (MHz). By performing high brightness using a square wave operation method with the low frequency below 100kHz, which is applied to a narrowed tube type lamp that has several mm of lamp diameter, an EEFL presented the possibility of using it as a light source for backlights. However, because an EEFL generates plasma using wall charges, which considers the impedance characteristics of glass based on the structural principle in discharge, it can be significantly affected by frequency. Thus, this study verifies the change in the characteristics of electromagnetic fields according to the change in frequency through a Maxwell's electromagnetic field simulation and examines the relationship between the change in the EEFL frequency and brightness by measuring the optical characteristics. In addition, the characteristics of the transformation of energy orbits were verified by investigating the characteristics of the wavelength according to the change in frequency through the OES.

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NEAR-IR PHOTOMETRIC AND OPTICAL SPECTROSCOPIC STUDY OF THE FU ORIONIS OBJECT V582 AURIGAE

  • OH, HYUNG-IL;YOONY, TAE SEOG;SUNG, HYUN-IL
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.269-270
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    • 2015
  • We carried out near-IR photometric and optical spectroscopic observations of V582 Aur, which is a FU Orionis type object, to investigate any periodic and/or aperiodic variations. We obtained light curves on the scale of a night and a year, in J, H and Ks bands with KASINICS (KASI Near Infrared Camera System) attached to the BOAO (Bohyun-san Optical Astronomy Observatory) 1.8-m reflector in Youngcheon, South Korea and examined photometric variations on the two time scales. So far we have not found any periodic brightness variations on the scale of a night. On the other hand, we have found that there seems to be a periodic brightness variation with a period of approximately 45 days. In addition, high-resolution optical spectroscopic observations of V582 Aur were performed from February 2013 to May 2014 with the high-resolution echelle spectrograph BOES attached to the BOAO 1.8-m reflector. We analyzed several spectral lines to understand the physical state of V582 Aur. The P Cyg profiles are clearly shown in the $H{\alpha}$ line and Na I D line.

Fabrication and Characterization of Film Type Light Guide Plates by UV Imprint Lithography (UV 임프린팅법에 의한 필름형 광도광판의 제조 및 특성 연구)

  • Kim, Hyeong-Gwan;Kim, So-Won;Lee, Hee-Chul
    • Journal of the Korean institute of surface engineering
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    • v.49 no.2
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    • pp.178-185
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    • 2016
  • In this study, we have fabricated light guide plates (LGPs) in thin film form for edge type back light unit (BLU) by using UV imprint lithography. In the LGPs, the pattern of functional resins on PC and PMMA substrates were successfully transferred from original master mold through PVC stamp. Optimized pattern arrays with slowly-sloped density were designed to obtain high brightness and uniformity. We could obtain a relatively improved brightness of $950cd/m^2$ and a uniformity of 87.3% by using the NP-S20 functional resins at an input power of 1.3 W because NP-S20 resin could show high formability after UV hardening process. The LGP prepared on polymethylmethacrylate (PMMA) substrate exhibited higher brightness than that on polycarbonate (PC) substrate because PMMA has lower refractive index resulting in more refraction toward the vertical direction.