• Title/Summary/Keyword: CRT-A

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A Psychophysical Approach to the Evaluation of Perceived Focusing Quality of CRT Displays

  • Yoon, Kwang-Ho;Kim, Sang-Ho;Chang, Sung-Ho
    • Journal of Information Display
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    • v.5 no.3
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    • pp.35-40
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    • 2004
  • In this study, we collected data used to formulate the relationship between quantitative metrological parameters in CRT display and the perceived focus quality. Human perception of the focusing quality was evaluated in terms of user feedback scores regarding the character legibility from four highly trained inspectors. Thirteen CRT monitors from five different manufacturers were compared relatively with respect to the norm monitor. The profile of electron beam such as spot size and the shape of distribution made by electron beam, contrast, convergence of RGB beams, and luminance characteristics were measured using a precision measurement system. Linear regression analysis and artificial neural network models were used to formulate the relationship between human perception and the quantitative measurements. The accuracy of the formulated linear regression model ($R^2$=0.515) was not satisfactory but the nonlinear neural network model ($R^2$=0.716) was fairly convincing and robust even the utilized data included subjective differences.

A Study on digital color proofing method considering the printing characteristics of output device (출력장치의 인쇄특성을 고려한 디지털 컬러교정에 관한 연구)

  • 송경철;강상훈
    • Journal of the Korean Graphic Arts Communication Society
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    • v.18 no.2
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    • pp.69-82
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    • 2000
  • Recently, as the prepress mainstream is changed to the digital workflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. CRT monitors are also often used as a soft proofing device. However, it is very difficult to match the color image displayed on CRT monitors to the actual images printed on papers, because the color space of CRT monitors is RGB color system, and it is different with the CMY color system of the printing devices. Therefore, proper color compensations are needed to match the colors between hard-copy proofs on the printing device and soft copy proofs on CRT monitors. This paper shows the LUT and gamut mapping method considering the printing characteristics of output device is useful for the compensation.

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Color reproduction algorithm considering background effect on a CRT display (CRT 디스플레이의 바탕 화면 영향을 고려한 색 재현 알고리즘)

  • 박승옥;김홍석;조대근
    • Korean Journal of Optics and Photonics
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    • v.9 no.1
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    • pp.38-46
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    • 1998
  • In this study, the color reproduction algorithm considering both of luminace and chromaticity of the background light is presented and tested to BT-H 1450 monitor(Panasonic). In the case of neglecting the background effect, the Macbeth ColorChecker's 24 colors are reproduced with the average color difference ${\Delta}E_{ab}^{*}$ more than 9.0. By using this method, the average color difference ${\Delta}E_{ab}^{*}$ is decreased less than 1.0. From this study, we can find that both of luminance and chromaticity of background light are very important factors in the color reproduction on a CRT display.

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Optimized TOF-PET detector using scintillation crystal array for brain imaging

  • Leem, Hyuntae;Choi, Yong;Jung, Jiwoong;Park, Kuntai;Kim, Yeonkyeong;Jung, Jin Ho
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2592-2598
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    • 2022
  • Research groups in the field of PET instrumentation are studying time-of-flight(TOF) technology to improve the signal-to-noise ratio of PET images. Scintillation light transport and collection plays an important role in improving the coincidence resolving time(CRT) of PET detector based on a pixelated crystal array. Four crystal arrays were designed by the different optical reflection configuration such as external reflectors and surface treatment on the CRT and compared with the light output, energy resolution and CRT. The design proposed in the study was composed of 8 × 8 LYSO crystal array consisted of 3 × 3 × 15 mm3 pixels. The entrance side was roughened while the other five surfaces were polished. Four sides of all crystal pixels were wrapped with ESR-film, and the entrance surface was covered by Teflon-tape. The design provided an excellent timing resolution of 210 ps and improved the CRT by 16% compared to the conventional method using a polishing treatment and ESR-film. This study provided a method for improving the light output and CRT of a pixelated scintillation crystal-based brain TOF PET detector. The proposed configuration might be an attractive detector design for TOF brain PET requiring fast timing performance with high cost-effectiveness.

Comparison of Visual Task Performance between CRT and TFT-LCD

  • Kim, Sang-Ho;Chang, Sung-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.1064-1067
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    • 2002
  • The effects of different optical characteristics between desktop CRT and TFT-LCD were compared in terms of visual performance during a 4-hr visual text and icon search tasks. The result showed that CRT is more suitable for presenting graphic information whereas TFT-LCD is suitable for presenting text information at the state of the art display technology.

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The Security Analysis of Previous CRT-RSA Scheme on Modified Opcode and Operand Attack (연산자 조작 공격과 피연산자 조작 공격에 대한 기존 CRT-RSA Scheme의 안전성 분석)

  • Hur, Soon-Haeng;Lee, Hyung-Sub;Rhee, Hyun-Seung;Choi, Dong-Hyun;Won, Dong-Ho;Kim, Seung-Joo
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.6
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    • pp.185-190
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    • 2009
  • As the use of RSA based on chinese remainder theorem(CRT-RSA) is being generalized, the security of CRT-RSA has been important. Since Bellcore researchers introduced the fault attacks on CRT-RSA, various countermeasures have been proposed. In 1999, Shamir firstly proposed a countermeasure using checking procedure. After Shamir's countermeasure was introduced, various countermeasures based on checking procedure have been proposed. However, Shamir's countermeasure was known to be vulnerable to the modified operand attack by Joey et al. in 2001, and the checking procedure was known to be vulnerable to the modified opcode attack by Yen et al. in 2003. Yen et al. proposed a new countermeasure without checking procedure, but their countermeasure was known to be also vulnerable to the modified operand attack by Yen and Kim in 2007. In this paper, we point out that pre, but countermeasures were vulnerable to the modified operand attack or the modified opcode attack.

Molecular Cloning and Overexpression of Phytoene Desaturase (CrtI) from Paracoccus haeundaensis

  • Choi, Seong-Seok;Seo, Yong Bae;Lim, Han Kyu;Nam, Soo-Wan;Kim, Gun-Do
    • Microbiology and Biotechnology Letters
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    • v.46 no.2
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    • pp.145-153
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    • 2018
  • Among the carotenoid biosynthesis genes, crtI gene encodes the phytoene desaturase (CrtI) enzyme, and phytoene desaturase convert phytoene to lycopene. Phytoene desaturase is involved in the dehydrogenation reaction, in which four single bonds in the phytoene are introduced into a double bond, eliminating eight hydrogen atoms in the process. Phytoene desaturase is one of the key regulating enzyme in carotenoid biosynthetic pathway of various carotenoid biosynthetic organisms. The crtI gene in genomic DNA of Paracoccus haeundaensis was amplified and cloned into a T-vector to analyze the nucleotide sequence. As a result, the crtI gene coding for phytoene desaturase from P. haeundaensis consists of 1,503 base pairs encoding 501 amino acids residues. An expression plasmid containing the crtI gene was constructed, and Escherichia coli cells containing this plasmid produced the recombinant protein of approximately 55 kDa, equivalent to the molecular weight of phytoene desaturase. The expressed protein in cell lysate showed enzymatic activity similar to phytoene desaturase. Phytoene and lycopene were analyzed by HPLC and measured at wavelength of 280 nm and 470 nm, respectively. The $K_m$ values for phytoene and NADPH were $11.1{\mu}M$ and $129.3{\mu}M$, respectively.

Correlation of Caries Experience and Activity between Mothers and Their Children Using a Colorimetric Test (비색법을 이용한 모자간 우식 경험 및 활성의 상관성)

  • Jang, So-young;Lee, Koeun;Song, Je Seon;Kim, Seong-Oh;Lee, Jaeho;Choi, Hyung-Jun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.45 no.2
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    • pp.162-169
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    • 2018
  • The purpose of this study was to compare the validity of $Cariview^{(R)}$, a new colorimetric caries activity test, with $CRT^{(R)}$ bacteria, a conventional bacterial culture method. In addition, this study assesses the correlation between the dental caries experience and activity between mothers and their children. 34 pairs of mothers and their children under the age of 6 years participated in this study with informed consent. After filling out a questionnaire and oral examination, the two caries activity tests above were performed on each subject. In the results, $Cariview^{(R)}$ scores were statistically significant with children's caries experience (r = 0.598, p < 0.01) and showed higher correlation than $CRT^{(R)}$ bacteria scores. $Cariview^{(R)}$ scores showed statistically significant correlation with the number of decayed teeth in both mothers and children (p < 0.05). In both $Cariview^{(R)}$ and $CRT^{(R)}$ bacteria tests, there was no statistically significant correlation between caries experience and caries activity (p > 0.05). $Cariview^{(R)}$ colorimetric test will be clinically useful for predicting future caries risk and establishing a preventative strategy in pediatric dentistry.

measurement for optical engine of CRT rear projection HDTV (HDTV용 CRT 프로젝션 광학엔진의 MTF 측정 연구MTF)

  • Song, Jong-Sup;Lee, Ji-Young;Lee, Yun-Woo;Lee, Hoi-Youn;Lee, In-Won;Jo, Jae-Heung;Kim, Jin-Ho;Park, Sang-Kyung
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.34-35
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    • 2002
  • Large-screen projectors for video applications and computer monitors are convenient instruments for conference presentations as well as for TV use at home. Recently, CRT and LCD projectors have achieved higher resolutions and luminance in the projection TV The large surface of the CRT compared to the LCD allows a great number of pixels to be displayed, while simultaneously providing maximum brightness of the final picture. (omitted)

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Electron Reflecting Layer with the WO3-ZnS:Cu.Al-PbO-SiO2 System Concerned in Doming Property of Shadow Mask in CRT

  • Kim, Sang-Mun;Cho, Yoon-Lae
    • Journal of the Korean Ceramic Society
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    • v.39 no.12
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    • pp.1124-1127
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    • 2002
  • In this paper, we studied the effects of the electron reflection on shadow mask on which the electron reflecting materials with $WO_3-ZnS:Cu.Al-PbO-SiO_2$ system were screen-printed and we evaluated the variation of the electron beam mislanding in CRT. As a result, the green emitted spectra on the electron reflecting layer are observed due to the transformation of the electron energy, when the electron impacted on shadow mask. The beam mislanding is reduced about 40% in comperision with that of CRT made by the conventional method.