• Title/Summary/Keyword: Comb Type

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A Study on the Hair Ornaments in the Period of the Three Kingdom States (삼국시대 머리 장신구에 대한 연구)

  • 김문자
    • The Research Journal of the Costume Culture
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    • v.9 no.5
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    • pp.712-722
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    • 2001
  • The purpose of this study is to classify of the Hair ornaments in old tombs of the Three Kingdom States. Hair ornaments was divided into Combs, Rod-like hairpins, Chae[;釵], Boyo[;步搖] Combs were 2 type in according to the tooth's space, wide-tooth comb[;梳] and fine-tooth comb(;比). The general name of two type was called Jeul(;櫛). Combs were excavated from the only ancient Silla tombs. Rod-like hairpins were called Gha(叉) or Jam(:簪). They were found in most of the old tombs in Goauryeo, Baekje, ancient Silla tombs. The style was L-type and embellished circular head-type. Chae(;釵) was understand Cha(:叉) that had two tongs. Chae(:釵) was generally U-type and rarely hairtweezers -type. Jakchae(;爵釵) was understand distinctive Chae(;釵) hanged with phoenix. This type was excavated from the only Baekje tombs of King of Muryeong. Boyo(;步搖) was originally a hair decoration of the northern nomadic tribes which had been introduced to the Wijin period. Boyo gained its popularity by the women in Dang Dynasty, hair ornaments were considered indicators of status and wealth. Boyo(;步搖) hair accessory features of which are suspended from a elaborate hairpin structure. Such pieces were designed to sway as their wearer walked. The bequest was not found, but we catch the Boyo(; 步搖) that was women'head decoration in painting of old tombs in Goguryeo.

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Iterative OFDM channel estimation scheme based on comb-type pilot (Comb-type pilot 을 이용한 OFDM 시스템 반복 채널 추정 기법)

  • Park, Hye-Mi;Lee, Jae-Hong
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.297-300
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    • 2005
  • 본 논문은 빠른 페이딩 환경에서의 OFDM 시스템 채널 추정 기법에 대하여 소개한다. 기존의 OFDM 채널 추정 기법은 준 정적인 채널 환경을 가정하여 전개되었다. 이러한 환경에 대한 가정을 기반으로 하는 채널 추정 기법은 OFDM 블록내에서 채널이 변하는 빠른 페이딩 환경에서 심각한 에러 플로어를 겪게된다. 따라서 본 논문에서는 OFDM 블록내에서도 채널이 변한다는 가정하에 시간과 주파수 두개의 차원에서의 상관성를 이용하여 ICI 를 제거하여 반복적으로 채널을 추정하는 기법을 제안한다.

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Modified MMSE Estimator based on Non-Linearly Spaced Pilots for OFDM Systems

  • Khan, Latif Ullah
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.1
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    • pp.35-39
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    • 2014
  • This paper proposes a Modified Minimum Mean Square Error (M-MMSE) estimator for an Orthogonal Frequency Division Multiplexing (OFDM) System over fast fading Rayleigh channel. The proposed M-MMSE estimator considered the effects of the efficient placement of pilots based on the channel energy distribution. The pilot symbols were placed in a non-linear manner according to the density of the channel energy. Comparative analysis of the MMSE estimator for a comb-type pilot arrangement and M-MMSE estimator for the proposed pilot insertion scheme revealed significant performance improvement of the M-MMSE estimator over the MMSE estimator.

Analysis of Transmission Spectrum Characteristics of Second-Order Fiber Flexible Comb Filter Based on Polarization-Diversity Loop (편광상이 고리 기반 2차 광섬유 유연 빗살 필터의 투과 스펙트럼 특성 분석)

  • Park, Kyoungsoo;Lee, Yong Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.12
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    • pp.1-7
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    • 2015
  • In this paper, we propose a second-order fiber flexible comb filter based on a polarization-diversity loop(PDL). The proposed filter consists of a polarization beam splitter, four half-wave plates(HWPs), and three high birefringence fiber(HBF) segments. In the previous Solc-type second-order filter based on the PDL, HBF segments were fusion-spliced with a fixed angle offset between their principal axes with each other. But, the proposed filter implemented by inserting two HWPs between three HBF segments has a great flexibility in adjusting relative angular difference between the principal axes of two adjacent HBF segments. Owing to this flexibility, second-order transmission spectra, which had a channel spacing of ~0.8nm, could be interleaved by controlling the orientation angles of four HWPs. The output transmission spectra of the proposed filter were theoretically analyzed and experimentally verified.

Development of Plasma Confinement by Applying Multi-Polar Magnetic Fields in an Internal Inductively Coupled Plasma System (선형 유도결합 플라즈마 시스템에서 자장에 의한 플라즈마의 Confinement 효과에 관한 연구)

  • Lim, Jong-Hyeuk;Kim, Kyong-Nam;Yeom, Geun-Young
    • Journal of the Korean institute of surface engineering
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    • v.39 no.3
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    • pp.142-146
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    • 2006
  • A novel internal-type linear inductive antenna, which we refer to as a double comb-type antenna, was developed for a large-area plasma source with substrate size of $880\;mm{\times}660\;mm$ ($4^{th}$ generation glass size). In this study, effect of plasma confinement by applying multi-polar magnetic field was investigated. High density plasmas of the order of $3.18{\times}10^{11}\;cm^{-3}$ could be obtained with a pressure of 15 mTorr Ar at an inductive power of 5000 W with good plasma stability. This plasma density is higher than that obtained for the conventional double comb-type antenna, possibly due to the plasma confinement, low rf voltage, resulting in high power transfer efficiency. Also, due to the remarkable reduction in the antenna rf voltage and length, a plasma uniformity of less than 3% could be obtained within a substrate area of $880\;mm{\times}660\;mm$ as rf power increased.

Acquirement of cross-sectional image by using wavelength swept laser within the two SOAs parallel configuration (병렬 SOA 구조의 파장가변 레이저를 이용한 단면 영상획득)

  • Kim, Hoon-Sup;Eom, Jin-Seob
    • Journal of Industrial Technology
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    • v.28 no.B
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    • pp.239-244
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    • 2008
  • We have realized the swept source optical coherence tomography(SS-OCT) by using the self-fabricated wavelength swept laser(wavelength tuning range : 80nm, line-width : 0.12nm, wavelength sweeping rate : 50Hz). In addition, we have used the dual balanced detector that could make a mirror image in OCT display suppressed. We can also fabricate the comb filter of Michelson interferometer type for fast-signal processing in OCT. Using this SS-OCT system for measuring an mirror, a 1mm-depth glass and an onion, we confirmed that the in vivo epidermal cross-sectional images for them can be obtained appropriately.

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Goniotrichopsis reniformis (Kajimura) Kikuchi comb. nov. (Stylonematales, Rhodophyta) from Japan

  • Kikuchi, Norio;West, John A.;Kajimura, Mitsuo;Shin, Jong-Ahm
    • ALGAE
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    • v.21 no.2
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    • pp.185-191
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    • 2006
  • The morphology and life history of Stylonema reniforme Kajimura (Stylonematales, Rhodophyta) from Japan were investigated and its taxonomic placement was discussed. This species has 6-30 discoid chloroplasts devoid of a pyrenoid in each cell. This is a typical feature of the genus Goniotrichopsis. The species reproduced only by monospores, which were formed by the direct transformation of the vegetative cells similar to the type species Goniotrichopsis sublittoralis Smith. Goniotrichopsis reniformis (Kajimura) Kikuchi comb. nov. was proposed. The asexual life history of the present species was completed in 3-10 weeks at $15-20^{\circ}C$ in culture.

Novel Channel Estimation Method in Fast Fading Channels Applied to LTE-Advanced (LTE-Advanced에 적용되는 빠른 페이딩 채널의 새로운 채널 추정 방법)

  • Malik, Saransh;Portugal, Sherlie;Moon, Sang-Mi;Kim, Bo-Ra;Kim, Cheol-Sung;Hwang, In-Tae
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.5
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    • pp.51-58
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    • 2012
  • Accurate transmission and estimation of the channel statistics affected by high Doppler spread is one of the main issues of concern for the latest and future mobile communication systems. Therefore, it is important to research in novel channel estimation techniques that overcome the limitations of conventional methods. In this paper, we propose a novel channel estimation method that, after a simple estimation in the first OFDM symbol, uses Kalman filter to predict the channel in the rest of OFDM symbols with pilot subcarriers. Our method is designed considering the lattice-type arrangement of pilot subcarriers in LTE-Advanced, since most of the studies so far focus on block-type or comb-type pilot arrangements. In addition, to optimize the results, we use the filtering of channel impulse response and Wiener Filter for the estimation of the channel frequency response in the rest of the subcarriers.

Two New Records of Peyssonnelia Species and Sonderophycus cauliferus Comb. Nov. within the Family Peyssonneliaceae (Peyssonneliales) from Korea

  • Jeong, So Young;Bustamante, Danilo E.;Lee, Jin Gyo;Won, Boo Yeon;Kim, Seung Hee;Cho, Tae Oh
    • Korean Journal of Environmental Biology
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    • v.35 no.3
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    • pp.345-353
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    • 2017
  • Detailed morphological studies and molecular analyses based on plastid-encoded rbcL gene sequences were undertaken on Peyssonnelia species, a poorly known genus from Korea. We report new records for the Korean coast, Peyssonnelia harveyana and P. rumoiana. Peyssonnelia harveyana is chiefly characterized by P. rubra-type anatomy, closely packed perithallial filaments in firm matrix, hypothallial filaments arranged in parallel rows, thalli with appressed margins, hypobasal calcification, and unicellular rhizoids. Peyssonnelia rumoiana is principally characterized by two vegetative features, hypothallial filaments arranged in a polyflabellate layer, and perithallial filaments arising from the whole upper surface of each hypothallial cell (Peyssonnelia rubra-type anatomy). Our rbcL analyses revealed that P. harveynana and P. rumoiana were placed within a clade of Peyssonnelia. We also propose the new combination, Sonderophycus cauliferus comb. nov., for previous Peyssonnelia caulifera. Phylogenetic analyses revealed that our S. cauliferus was placed within a clade of Sonderophycus.

Study on Analysis of Output Polarization of Lyot-Type High-Order Fiber Comb Filter Based on Polarization-Diversity Loop Structure (편광상이 고리 구조 기반 Lyot형 고차 광섬유 빗살 필터의 출력 편광 분석에 관한 연구)

  • Jo, Songhyun;Lee, Yong Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.10
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    • pp.17-24
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    • 2015
  • In this paper, we investigated the output polarization of a Lyot-type optical fiber comb filter based on a polarization-diversity loop structure. It was found that the output state of polarization (SOP) of the filter made a wavelength-dependent evolution, and the spectral periods of the output SOP variation in flat-top and lossy flat-top band modes were the channel separation of the filter and its half, respectively. For a certain input SOP, the filter could pass or reject specific spectral sections by adding and controlling an output analyzer. In particular, it was theoretically anticipated that the filter with the output polarizer could provide the fine continuous tuning of its pass band center in a wavelength range corresponding to the ${\pm}9.5%$ of channel spacing(0.8nm) when the input SOP was properly adjusted. It is expected that this tuning function can be effectively applied to suppress unwanted spectral portions in modulated optical signals.