• Title/Summary/Keyword: High PAE

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Effect of Particle Contamination on Objective Lens in a CD-ROM Drive on Laser Diode Power and Photo Diode RF Signal (CD-ROM 드라이브의 대물렌즈 입자오염이 Laser Diode의 Power와 Photo Diode의 RF Signal에 미치는 영향)

  • Pae, Yang-Il;Hwang, Jung-Ho
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1429-1434
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    • 2003
  • A number of dust particles are intruded into ODD(Optical disk drive) due to the flow caused by disk rotation and are adhered to a lens or disk surface. The space between the disk and the lens is being reduced. Someone indicates the problems of this drive that are relatively small data storing capacity and slow access time. In recent, the problems of this optical disk drive mentioned above are being solved by adding the speed of the disk's revolution, making the actuator high-speed or light, and making the beam spot size smaller than making the space narrow between disk and lens. These particle contamination affects seriously RF Signal, readout signal in an ODD. Especially, the affected parts by a particle contamination in an ODD's readout signal are objective lens and media.

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Integratable Micro-Doherty Transmitter

  • Lee, Jae-Ho;Kim, Do-Hyung;Burm, Jin-Wook;Park, Jin-Soo
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.6 no.4
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    • pp.275-280
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    • 2006
  • We propose Doherty power amplifier structure which can be integrated in Silicon RF ICs. Doherty power amplifiers are widely used in RF transmitters, because of their high Power Added Efficiency (PAE) and good linearity. In this paper, it is proposed that a method to replace the quarter wavelength coupler with IQ up-conversion mixers to achieve 90 degree phase shift, which allows on-chip Doherty amplifier. This idea is implemented and manufactured in CMOS 5 GHz band direct-conversion RF transmitter. We measured a 3dB improvement output RF power and linearity.

Multiresolution Independent Component Analysis for Iris Identification

  • Noh, Seung-In;Kwanghuk Pae;Lee, Chulhan;Kim, Jaihie
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1674-1677
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    • 2002
  • In this paper, the new method to extract the features of iris signals is proposed; Multiresolution ICA (M-ICA) provides good properties to represent signals with time-frequency. The conventional methods were to use the technique of filter bank analysis, while ICA is unsupervised learning algorithm using high-order statistics. M-ICA could make use of strengths of learn- ing method and multiresolution. Also, we performed comparative studies of different feature extraction techniques applied to personal identification using iris pat- tern. To measure goodness of methods, we use Fisher’s discriminant ratio to quantify the class-separability of features generated by various techniques.

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Bromine-Exchange Reaction of Antimony Tribromide with Benzyl Bromide in Nitrobenzene and in 1,2,4-Trichlorobenzene$^*$

  • Choi Sang Up;Pae Young Il;Rhyu Sok Hwan
    • Bulletin of the Korean Chemical Society
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    • v.3 no.2
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    • pp.55-60
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    • 1982
  • The rate of the bromine-exchange reaction of antimony tribromide with benzyl bromide in nitrobenzene or 1,2,4-trichlorobenzene has been measured, using Br-82 labelled antimony tribromide. The result of the study indicates that the exchange reaction is first order with respect to benzyl bromide, and either second or first order with respect to antimony tribromide depending on its concentrations. The second-order kinetics with respect to antimony tribromide have been observed at relatively high $[SbBr_3]$ concentrations, and the first-order kinetics at lower $[SbBr_3]$ concentrations. Reaction mechanisms are proposed for the exchange reaction.

A study of Symbolics of Chinese Liturgical Vestments (중국 제복의 상징성에 관한 연구)

  • 이선희
    • Journal of the Korean Society of Costume
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    • v.18
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    • pp.111-131
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    • 1992
  • This thesis was designed to study Symbolics of Chinese Liturgical Vestments. Chinese who regarded the life of human beings as the combination of heaven and earth considered garments as the traditional product of the movement of nature. Accordingly, they thought human beings are the center of the universe composed by heaven and earth and the chief of all things; therefore man only can utilize clothes to distinguish from all of the colours. This views of clothes led to the development of liturgical vestments esteemed courtesy than anything else, especially the thought of courtesy associated with Conficius who regarded courtesy as the highest things and since then the theory of Five Elements and courtesy were inherited by all the adherents of Conficius. Yin and Yang Five Elements in the liturgical vestments was given absolute symbolics in both formative side and in colourful side. results of research studied in this was can be summed up as follows : 1. The crown of rites was made imitating after the system of head, horn, beard, bread of birds and beasts and that form of crown is front-circ-ular and back-rectangular meant to be towards light and dark. That the upper part of faceplace is black represented the way of heaven and lower part of red symbolized the way of earth. 2. Upper vestment of liturgical rites symbolizes heaven and outskirt represented earth. So front of outskirt is YANG and back is Yin. It is why then are going to harmonize positive and negative making front part three width and back part four width. Therefore, emperor who symbolizes heaven made the subjects recognize high and low and wore Dae-gu(大 ), Kon-bok(袞服), Bel-bok, Chui-bok, and Hyonbok according to the object and position of rites so that he may rule the country based on courtesy. 3. As an accessory of liturgical vestments, Bul, Pae-ok, Su, Dae-dai, Hyok-Dai, Kyu, and Hol were used. Before Bul was used man dressed skirt as the first waist-dress in order to conceal intimate part of the body. Pae-ok, as decoration blended with jade was worn by men of virtue, so men of virtue symbolized morality and virtue by Pae-ok. Su began from Yeok, connected with Pae-su , in Chou-dynasty is said to be originated by practical needs and they are divided into large Su and small su, and maintained as decoration to signify the class positions. Dae-dai did the work as not to loose the liturgical vestments and leather belt hang Bul and Su to begin as the function of practical use are in later years it became decoration to symboliz e the class position. Kyu was a jade used when empeor nominated feudal lords and observe ceremony to God and Hol, was held in hands to record everything not to forget. These Kyu and Hol became to offer courtesy during the time of rites and in later years it became used according to class position rather than practical use. 4. As far as colours are concerned, colours based by five colours according to YIN-YANG Five Elements theory and they were divided into a primary colour and a secondary colours. Primary colours corresponded with the theory of Five Elements each other, Blue, Red, Tellow, White, and Black symbolized ive Elements, five hour space, five directions, and five emperors. Secondary colours contradict with Blue, Red, Yellow, White and Black and another as a primary colour and they are Green, Scaret, Indigo, Violet, Hun colour, Chu colour, and Chi colour. This primary colour was used in liturgical vestments, that is, upper-vestments used black colour. This primary colour was used in liturgical vestments, that is, upper-vestments used black colour as primary colour and outskirt was used Hun colour as secondary colours. Thus symbolism in chinese liturgical vestments mainly began with heaven and earth and corresponded with YIN-YANG Five Elements Scool. They were developed as the scholary theory and Conficius and his followers in the later days and continued up to Min-dynasty.

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Fabrication and Characterization of Dielectric Materials of Front and Back Panel for PDP

  • Chang, Myeong-Soo;Pae, Bom-Jin;Lee, Yoon-Kwan;Ryu, Byung-Gil;Park, Myung-Ho
    • Journal of Information Display
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    • v.2 no.3
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    • pp.39-43
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    • 2001
  • The glass compositions of $PbO-SiO_2-B_2O_3$ system and $P_2O_5-PbO-ZnO$ system for the transparent dielectric materials for front panel and $P_2O_5$-ZnO-BaO and $SiO_2-ZnO-B_2O_3$ for the reflective dielectric materials for back panel of PDP (Plasma Display Panel) were investigated. As a result, transparent dielectric materials for front panel showed good dielectric properties, high transparency, and proper thermal expansion matching to soda lime glass substrate. And the reflective dielectric layers for back panel were prepared from two series of parent glass and oxide filler. It was found that these glassceramics are useful materials for dielectric layers in PDP device, as they have similar thermal expansion to soda-lime glass plate, high reflectance, and low sintering temperature. In particular, the addition of $BPO_4$ and $TiO_2$ as fillers to $SiO_2-ZnO-B_2O_3$ system is considered to be the most effective for acquiring good properties of lower dielectric layer for PDP device.

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Control of HVDC-MMC Considering the Switching Device's Current Capacity and Circulating Current under Unbalanced Voltage Conditions (불평형 전압 조건에서 스위칭 소자의 전류 용량과 순환전류를 고려한 HVDC-MMC 제어기법)

  • Moon, Ji-Woo;Pae, Deuk-Woo;Park, Jung-Woo;Kang, Dea-Wook;Yoo, Dong-Wook;Kim, Jang-Mok
    • The Transactions of the Korean Institute of Power Electronics
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    • v.18 no.3
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    • pp.270-278
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    • 2013
  • This paper proposes a control method for high voltage direct current(HVDC) with modular multilevel converter (MMC) under unbalanced voltage conditions considering the submodule(SM)'s current capacity and circulating current. It is aimed to propose a control method in which the current peak value does not exceed the maximum value of HVDC-MMC by considering the current capacity of the SM under unbalance voltage conditions. And it analyzes the effect of the unbalanced voltage on circulating currents in MMC and then proposes a control method considering each component of circulating currents under unbalanced voltages. The effectiveness of the proposed controlling method is verified through simulation results using PSCAD/EMTDC.

Design and fabrication of Power Amplifier with HBT for IMT-2000 Handsets (IMT-2000 단말기용 HBT 전력증폭기 설계 및 제작)

  • 정동영;박상완;정봉식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.2
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    • pp.276-283
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    • 2003
  • In this paper, a 2-stage power amplifier(PA) for IMT-2000 handset has been designed and fabricated using SiGe HBT, which has excellent frequency characteristics and linearity, to reduce size and weight instead of existing linearization techniques. DC I-V characteristics and S-parameter of SiGe HBT were simulated by Agilent circuit simulator(ADS), with large signal Gummel-Poon nonlinear circuit model. Then the output and interstage matching circuits were designed to satisfy the high power condition and the high gain condition, respectively. The experimental results showed output power of 27.1dBm and ACLR of 20dB, PAE of 34%, and linear power gain of 18.9dB over frequency ranges from 1920MHz to 1980MHz.

A Two-Stage Power Amplifier with a Latch-Structured Pre-Amplifier (래치구조의 드라이브 증폭단을 이용한 2단 전력 증폭기)

  • Choi Young-Shig;Choi Heyk-Hwan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.2
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    • pp.295-300
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    • 2005
  • In this paper we have designed a two-stage Class I power amplifier operated at 2.4CHz for Class-1 Bluetooth application. The power amplifier employs class-I topology to exploit its soft-switching property for high efficiency. The latch-structured pre-amplifier with amplifiers makes its output signal as sharp as possible for soft switching of the next power amplifier. It improves the overall efficiency of the proposed power amplifier. It shows 65.8$\%$ PAE, 20dB power gain and 20dBm output power.

Linearity Improvement of Class E Amplifier Using Digital Predistortion (디지털 사전왜곡을 이용한 마이크로파 E급 증폭기의 선형성 개선)

  • Park, Chan-Hyuck;Koo, Kyung-Heon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.3 s.357
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    • pp.92-97
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    • 2007
  • Switching mode amplifiers have been studied widely for use at microwave frequency range, and the class E amplifier which is a type of switching mode amplifier offers very high efficiency approaching 100%. In this paper, 2.4GHz microwave class E amplifier with 66% power added efficiency (PAE) and 17.6dBm output has been linearized for use at wireless LAN transmitter, and digital predistortion technique with look up table is applied. With -3dBm input power of wireless LAN, measured output spectrum can meet the required IEEE 802.11g standard spectrum mask, and the digital predistortion output spectrum has been improved by 5dB of ACPR at 20MHz offset from center frequency.