• Title/Summary/Keyword: center method

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Antiferroelectric Liquid Crystal Display with High Image Quality

  • Yu, Jeong-Seon;Chang, Young-Joo;Yoo, Jeong-Geun;Jeong, Dong-Jin;Park, Sung-Chon;Chae, Su-Yong;Yang, Hong-Geun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.545-547
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    • 2002
  • The antiferroelectric liquid crystal display (AFLCD) is unique display that can show the perfect moving image using the passive matrix driving scheme. We optimized the driving waveform and introduced the dual driving method. Also, by improving this driving method and using line inversion method, we realized AFLC display with high image quality, which has 160(RGB)${\times}$240, 32768colors, crosstalk free and flicker free. The contrast ratio is greater than 60:1, and the brightness is above 200cd/$m^2$.

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High frequency partial discharge measurement by metal foil electrode (박전극을 이용한 고주파 부분방전 측정 연구)

  • Kim, C.S.;Shin, D.S.;Lee, C.Y.;Kim, J.N.;Baek, J.H.;Kim, D.W.;Park, W.K.
    • Proceedings of the KIEE Conference
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    • 1999.11d
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    • pp.1081-1083
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    • 1999
  • The capacitive coupling technique has been used as conventional method for PD detection on the power cable line. Recently, however PD measurement using by high frequency is known to have an excellent sensitivity comparison with low frequency on-site. In this paper, the high frequency characteristic of two type of metal foil sensor was studied and the technique was proved to be more effective diagnostic method than conventional method for qualification of EHV cable and accessories.

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Two-Degree-of-Freedom Controller Designed by Coefficient Diagram Method

  • Isarakorn, Don;Suksariwattanagul, Napatpong;Benjanarasuth, Taworn;Ngamwiwit, Jongkol;Komine, Noriyuki
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.262-267
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    • 2004
  • This paper is concerned with a design method of two-degree-of-freedom controller by Coefficient Diagram Method (CDM). The two-degree-of-freedom control system satisfies both of tracking and disturbance rejection performances, but requires tuning of many parameters. By the proposed design method, these parameters can be obtained properly without any adjustment. Furthermore, the tracking and disturbance rejection performances can be simultaneously designed. The effectiveness of the proposed method is demonstrated by the simulation.

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Improvement of 3-Dimensional Finite-Difference Beam Propagation Method by Combining the Implicit and the Explicit methods (Implicit와 explicit 방법의 결합에 의한 3차원 유한차분 빔전파 방법의 개선)

  • Kim, Hyun-Jun;O, Beom-Hoan;Park, Se-Geun;Lee, El-Hang;Lee, Seung-Gol
    • Korean Journal of Optics and Photonics
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    • v.15 no.6
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    • pp.555-562
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    • 2004
  • We propose a hybrid method combining the implicit with the explicit methods in order to reduce the calculation time and improve the convergence problem of the 3-dimensional finite-difference beam propagation method. The numerical simulation of a directional coupler is carried out by the proposed method. It is found from the simulation results that the calculation speed of our method is 10 times faster than that of direct solving techniques.

LED Delamination Evaluating Method by Thermal Shock Test (열충격시험을 통한 LED 박리 평가법에 관한 연구)

  • Jang, In-Hyeok;Han, Ji-Hoon;Ko, Min-ji;Lee, Young-Joo;Lim, Hong-Woo
    • Journal of Advanced Engineering and Technology
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    • v.6 no.2
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    • pp.121-124
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    • 2013
  • This paper proposed a new concept of estimating method for LED(light-emitting diode) delamination with high accuracy. Usually, The LED is composed several materials which are LED chips, gold wire, phosphor, epoxy resin, adhesive, reflector and lead frame. These different materials are usually delaminated in a trouble conditions which are huge temperature difference, hot and humid or mechanical shocked. When the components are delaminated, a luminance will be lost, moisture be absorbed easily and a thermal resistance be increased attendantly. As a conventional method to estimate a delamination of LEDs, a solution immersing method is usually used in a field of LED manufacturing companies or researching institutes. This method has an advantage of simplicity but it is only shown that the existence of delamination or not. In this paper, we have proposed an estimating method for LEDs delamination using the polishing and the electron microscope. New proposed method has shown the result of confirming delamination without destruction and enabled quantitative analysis for LED delamination.

LC-MS/MS Method for Simultaneous Analysis of Growth Hormone-Releasing Peptides and Secretagogues in Human Urine

  • Min, Hophil;Han, Boyoung;Sung, Changmin;Park, Ju-Hyung;Lee, Kang Mi;Kim, Ho Jun;Kim, Ki Hun;Son, Junghyun;Kwon, Oh-Seung;Lee, Jaeick
    • Mass Spectrometry Letters
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    • v.7 no.3
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    • pp.55-63
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    • 2016
  • Growth hormone (GH)-releasing peptides (GHRPs) and GH secretagogues (GHSs) are listed in the World Anti-Doping Agency (WADA) Prohibited List. In the present study, we developed and validated a method for the simultaneous analysis of seven GHRPs (alexamorelin, GHRP-1, -2, -4, -5, -6, and hexarelin) and three GHSs (anamorelin, ibutamoren, and ipamorelin) in human urine. Method validation was performed at minimum required performance levels specified by WADA technical documents (2 ng/mL) for all substances, and the method was validated with regard to selectivity (no interference), linearity (R2 > 0.9986), matrix effects (50.0%-141.2%), recovery (10.4%-100.8%), and intra- (2.8%-16.5%) and inter-day (7.0%-22.6%) precisions. The limits of detection for screening and confirmation were 0.05-0.5 ng/mL and 0.05-1 ng/mL, respectively.

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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A Novel Digital Driving Method for AM-OLED

  • Lee, Seung-Woo;Choi, Jae-Won;Jang, Jin;Chung, Hoon-Ju
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.837-840
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    • 2007
  • We propose a novel digital driving method for AM-OLED (Active Matrix-Organic Light Emitting Diode) display. Proposed method modulates $V_{DD}$ so that luminance may be weighted in accordance with the bit significance. We can increase the minimum emission time or slower scan circuits are applicable by using proposed method.

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Temperature Compensation Method of Local Dimming LED Backlight System

  • Oh, Won-Sik;Cho, Dae-Youn;Moon, Gun-Woo;Yang, Byung-Choon;Jang, Tae-Seok
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1401-1404
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    • 2008
  • Temperature Compensation Method of Local Dimming LED Backlight System is proposed. The luminance levels of the LED backlight are not stable over temperature and time due to the inherent characteristics of the LED. The characteristics of LED backlight are investigated and a temperature compensation method is presented. The image distortion caused by temperature variation of LED block can be effectively compensated by the proposed temperature compensation method.

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Analysis of 3D Microwave Oven Using Finite Element Method (전자렌지 캐비티의 전자파 해석)

  • Park, Kweong-Soo;Kim, Gweon-Jib;Shon, Jong-Chull;Kim, Sang-Gweon;Park, Yoon-Ser
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1753-1755
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    • 1996
  • This paper presents an analysis of the 3D microwave oven considering its forming. The results were compared with experimental data. Finite Element Method(FEM) using edge clement is employed for the analysis. For solving the large sparse system matrix equation was solved using the parallelized QMR method. Analysis of the 3d cavity has troublesome difficulties such as spurious solutions, too many memory and long computation time. We overcome this difficulties by using edge clement for spurious solutions and the parallelized QMR method by the aid of Paralle Virtual Machine(PVM) for the memory and computation time.

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