• Title/Summary/Keyword: Basic Characterization

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Signal Processing(I)-Mathematical Basis and Characterization of Signals by Covariance Functions (신호처리(I)-수학기초.Covariance로서 나타난 한 신호의 특질)

  • 안수길
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.16 no.6
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    • pp.1-10
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    • 1979
  • Recent progresses in the signal processing technique in digital domain as well as that of analogue, impose a heavy burden on scientists and engineers intending to study this dis cipline, we surveyed basic tools for these vast branches to help those who have concerns on this field without being buried in detailed techniques. The first article is naturally confined to the basic tools namely random process analysis and characterization of random signal by covariance function.

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Threshold-Based Camera Motion Characterization of MPEG Video

  • Kim, Jae-Gon;Chang, Hyun-Sung;Kim, Jin-Woong;Kim, Hyung-Myung
    • ETRI Journal
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    • v.26 no.3
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    • pp.269-272
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    • 2004
  • We propose an efficient scheme for camera motion characterization in MPEG-compressed video. The proposed scheme detects six types of basic camera motions through threshold-based qualitative interpretation, in which fixed thresholds are applied to motion model parameters estimated from MPEG motion vectors (MVs). The efficiency and robustness of the scheme are validated by the experiment with real compressed video sequences.

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Characterization of Via Etching in $CHF_3/CF_4$ Magnetically Enhanced Reactive Ion Etching Using Neural Networks

  • Kwon, Sung-Ku;Kwon, Kwang-Ho;Kim, Byung-Whan;Park, Jong-Moon;Yoo, Seong-Wook;Park, Kun-Sik;Bae, Yoon-Kyu;Kim, Bo-Woo
    • ETRI Journal
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    • v.24 no.3
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    • pp.211-220
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    • 2002
  • This study characterizes an oxide etching process in a magnetically enhanced reactive ion etching (MERIE) reactor with a $CHF_3/CF_4$ gas chemistry. We use a statistical $2^{4-1}$ experimental design plus one center point to characterize the relationships between the process factors and etch responses. The factors that we varied in the design include RF power, pressure, and gas composition, and the modeled etch responses were the etch rate, etch selectivity to TiN, and uniformity. The developed models produced 3D response plots. Etching of $SiO_2$ mainly depends on F density and ion bombardment. $SiO_2$ etch selectivity to TiN sensitively depends on the F density in the plasma and the effects of ion bombardment. The process conditions for a high etch selectivity are a 0.3 to 0.5 $CF_4$ flow ratio and a -600 V to -650 V DC bias voltage according to the process pressure in our experiment. Etching uniformity was improved with an increase in the $CF_4$ flow ratio in the gas mixture, an increase in the source power, and a higher pressure. Our characterization of via etching in a $CHF_3/CF_4$ MERIE using neural networks was successful, economical, and effective. The results provide highly valuable information about etching mechanisms and optimum etching conditions.

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Distribution of Chitinases in Rice (Oryza sativa L)Seed and Characterization of a Hull-Specific Chitinase

  • Baek, Je-Hyun;Han, Beom-Ku;Jo, Do-Hyun
    • BMB Reports
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    • v.34 no.4
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    • pp.310-315
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    • 2001
  • The uneven distribution of acidic and basic chitinases in different parts of rice seed, and also the characterization of hull-specific chitinases, are reported here. After extraction of chitinases from polished rice, bran, and rice hulls, the chitinases were separated into acidic and basic fractions, according to their behavior on an anion exchanger column. Both fractions from different parts of rice seed showed characteristic activity bands on SDS-PAGE that contained 0.01% glycol chitin. The basic chitinases from rice hulls were further purified using chitin affinity chromatography. The chitinase, specific to rice hulls (RHBC), was 88-fold purified with a 1.3% yield. RHBC has an apparent molecular weight of 22.2 kDa on SDS-PAGE. The optimal pH and temperature were 4.0 and $35^{\circ}C$, respectively. With [$^3H$]chitin as a substrate, RHBC has $V_{max}$ of 13.51 mg/mg protein/hr and $K_m$ of 1.36 mg/ml. This enzyme was an endochitinase devoid of ${\beta}$-1,3-glucanase, lysozyme, and chitosanase activities.

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Fabrication and characterization of a carbon nanotube-based point electron source

  • Choi, Ha-Kyu;Kim, G.Y.;Song, Y.I.;Jeong, H.J.;Lim, S.C.;Lee, Y.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1536-1537
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    • 2005
  • We have made point electron sources using carbon nanotubes (CNTs). For the fabrication of point electron sources, CNTs were dispersed in a solution and attached on electrochemically etched W tips using electrophoresis. In our study, we have utilized various CNTs such as single-walled CNT (SWCNT), multiwalled CNT (MWCNT), and thin-MWCNT and threshold current, turn-on voltage, filed enhancement factor of each emitter have been studied upon a tube/bundle diameter and length. In addition, fieldemitted electron energy distribution of various CNT emitters is characterized.

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Electrical Characterization of Nanoscale $Au/TiO_2$ Schottky Diodes Probed with Conductive Atomic Force Microscopy

  • Lee, Hyunsoo;Van, Trong Nghia;Park, Jeong Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.290.1-290.1
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    • 2013
  • The electrical characterization of Au islands on TiO2 at nanometer scale (as a Schottky nanodiode) has been studied with conductive atomic force microscopy in ultra-high vacuum. The diverse sizes of the Au islands were formed by using self-assembled patterns on n-type TiO2 semiconductor film using the Langmuir-Blodgett process. Local conductance images showing the current flowing through the TiN coated AFM probe to the surface of the Au islands on TiO2 was simultaneously obtained with topography, while a positive sample bias is applied. The boundary of the Au islands revealed a higher current flow than that of the inner Au islands in current AFM images, with the forward bias presumably due to the surface plasmon resonance. The nanoscale Schottky barrier height of the Au/TiO2 Schottky nanodiode was obtained by fitting the I-V curve to the thermionic emission equation. The local resistance of the Au/TiO2 nanodiode appeared to be higher at the larger Au islands than at the smaller islands. The results suggest that conductive atomic force microscopy can be used to reveal the I-V characterization of metal size dependence and the electrical effects of surface plasmon on a metal-semiconductor Schottky diode at nanometer scale.

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