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NOx Measurement of Diesel Exhaust Gas by Laser Induced Fluorescence (디젤배기가스의 레이저유기형광법에 의한 NOx 계측)

  • Jun, Yong-Woo;Choe, Joon-Yeong;Ha, Chang-Ho;Park, Won-Zoo;Lee, Kwang-Sik;Choi, Sang-Tae;Youn, Young-Dae
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2256-2258
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    • 1999
  • This paper describes preliminary discussions on spatial distribution of NO density, which is mostly contained in simulated NOx exhaust, between a wire-cylinder geometry discharge gaps by using Laser Induced Fluorescence(LIF) Spectroscopy, Spatial distribution of NO density will be measured with varying NO concentrations from 166 to 644 [ppm] and diameters of central electrode from 6 to 10mm. Pulsed Nd:YAG laser. Optical Parametric Oscillator(OPO), and Frequency Doubler are used to excite NO molecules to their excited state.

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Study on the plastic deformation of a cylinder subjected to localized impulsive pressure (국부충격하중을 받는 원관의 삭성변형에 관한 고찰)

  • ;;Zoo, Young Woo
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.5 no.2
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    • pp.131-138
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    • 1981
  • The effect of axial stress on the plastic deformation of rigid-perfectly plastic cylindrical tube under the impulsive band pressure is investigated. It is assumed that the tube is constructed with the material of Tresca's yield criterion. A closed from sloution is obtained for a rectangular pulse shape of uniform band pressure by using the circumscribed yield surface. The analysis shows that the effect ot exial stress is negligible when the dimensionless axial stress(n$\sub$x/= N$\sub$x/.delta.$\sub$y/H) is less than 0.2 or the dimensionless whdth of band pressure(.xi.=C/.root.RH) is greater than 2, but the effect of axial stress is of considerable importance when the axial stress is greater than 0.3 and the width of band pressure is less than 1.

Plasma-immersion ion Deposition of Hydrogenated Diamond-like Carbon Films on Dielectric Substrates

  • Kon;Chun, Hui-Gon;Cho, Tong-Yul;Nikolay S. Sochugov;You, Yong-Zoo
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.4
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    • pp.143-148
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    • 2002
  • Method of plasma-immersion ion deposition of hydrogenated DLC films on relatively thick flat dielectric substrates from plasma of not-self-sustained low-pressure gas arc discharge is suggested. Coating properties have been investigated experimentally, average energy Per a deposited carbon atom depending on discharge current has been calculated. Optimum deposition parameters lot obtaining sufficiently hard and transparent high-adhesive a-C:H films on a 4-mm thick glass substrates have been determined. Possibility to use these coatings for photo-tools protection from abrasion wear at low operating loads is shown in general.

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LCD Backlight Inverter Drive IC (액정디스플레이 후광 인버터 구동 IC)

  • Jeong, Dong-Youl;Jang, Cheon-Seob;Lee, Seung-Zoo
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2568-2571
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    • 2002
  • A LCD backlight inverter control IC based on the piezoelectric transformer (PZT) for Cold Cathode Fluorescent Lamp (CCFL) lighting is proposed. It is indeed a variable frequency, variable duty (VFVD) controller having dual feedback control loops for achieving both the regulation of lamp current and the maximum efficiency. The PWM controller regulates the lamp current, while the PLL controller tunes the operating frequency to the frequency that the efficiency of the combined LC-PZT resonator becomes maximum. The mixed PLL/PWM control technique lets the backlight inverter operate at the maximum efficiency in spite of the variation of component and environment. The controller features include a protection for an open or broken lamps, and an open lamp regulation.

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The Effect of Pyrogallol on the Pharmacological Action of Ephedrine and Epinephrine (Ephedrine 및 Epinephrine 의 작용(作用)에 미치는 Pyrogallol 의 영향(影響))

  • Lim, Zoo-Taek
    • The Korean Journal of Pharmacology
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    • v.4 no.1 s.5
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    • pp.41-44
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    • 1968
  • Pyrogallol is recently known to be a inhibitor of catechol-o-methyl transferase (COMT) and increase the action of epinephrine on the isolated rabbit atria. In this experiment, the author attempated to investigate the influence of pyrogallol on the effect of ephedrine and epinephrine on the blood pressure of the rabbit and isolated atria and excised intestine of the rabbit. The results obtained were summarized as follows; 1. Pyrogallol tends to increase the blood pressure and respiration of the rabbit. But it has no significant effect on the excised rabbit atria and intestine. 2. The effect of ephedrine on the blood pressure and respiration, isolated atria and excised intestine of the rabbit were not influenced by the pretreatment with pyrogallol. 3. The effect of epinephrine on the blood pressure and isolated atria of the rabbit is potentiated with pyrogallol pretreatment.

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A Study on the Characteristic of the Inductively Coupled $SF_6$ Plasma (유도 결합형 $SF_6$플라즈마 특성에 관한연구)

  • Ha, Jang-Ho;Jun, Yong-Woo;Song, Hyun-Jig;Park, Won-Zoo;Lee, Kwang-Sik;Lee, Dong-In
    • Proceedings of the KIEE Conference
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    • 1999.11d
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    • pp.1111-1113
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    • 1999
  • This paper represents the characteristic analysis for the etching in $SF_6$ plasma and the plasma itself, based on the specific knowledges on the discharge mechanism of $SF_6$ plasma which is widely used for the applications of dry etching, using Radio Frequency Inductively Coupled Plasma (RFICP) by measuring electron density, electron temperature then observing their relationship to find the effect of discharge mechanism of $SF_6$ plasma to the etching in contrast to the existing method of finding optimal discharge condition by heuristic.

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Depressor Responses to Intravenously Administered Perrillae Folium Juice (PFJ) in Cats (임엽(荏葉)(Perillae Folium)의 혈압강하 작용)

  • Sohn, Young-Zoo;Shin, Hong-Kee;Kim, Kee-Soon
    • The Korean Journal of Physiology
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    • v.16 no.2
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    • pp.147-152
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    • 1982
  • The present study was undertaken to investigate effects of Perillae Folium juice on the respiration and blood pressure in cats. Also studied was the mechanism of depressor action of PFJ. The results obtained are as follows; 1) Following administration of 0.2 ml/kg, 0.4 ml/kg and 0.6 ml/kg PFJ into cats the maximum depressor responses observed were 48.5+3.6 mmHg, 56.8+4.3 mmHg and 71.1+2.9 mmHg respectively. 2) Depressor responses to PFJ were blocked makedly by atropine and partially by propranolol. Therefore it is strongly suggested that depressor action of PFJ results mainly from cholinergic effect and partly from activity of ${\beta}-receptor$. 3) After administration of PFJ into cats tachypnea preceded by a short period of apnea was observed invariably.

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The Effect of Metal Back-reflective Layers on the Performance of Transfer Printed GaAs Solar Cells (금속 후면 반사막이 GaAs 태양전지의 효율에 미치는 영향)

  • Choi, Wonjung;Kim, Chang Zoo;Kang, Ho Kwan;Jo, Sungjin
    • Current Photovoltaic Research
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    • v.2 no.2
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    • pp.73-77
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    • 2014
  • To investigate the effect of metal back-reflective layers (MBLs) on the performance of GaAs solar cells, we fabricated GaAs solar cells on Al and Ag metal layers using the transfer printing technique. We also investigated the effect of MBL texturing on the performance of transfer printed GaAs solar cells. Transfer printed solar cells with MBLs exhibited improved photovoltaic performance compared to solar cells without MBLs due to light trapping. We demonstrated GaAs solar cells with MBLs on a flexible substrate and performed systematic bending tests. All the measured characteristics of solar cells showed little change in performance.

Pathophysiological Roles of AMP in Hypertrophied Heart

  • Chunhua Cao;Han, Jeong-Hee;Kim, Sung-Zoo;Cho, Kyung-Woo;Kim, Suhn-Hee
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.31-31
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    • 2003
  • Cardiac atrium is now well-known as an endocrine organ which secretes atrial natriuretic peptide (AMP), participating in the regulation of body fluid and blood pressure. ANP is released mainly from cardiac muscle cells in response to various physiological and pathological conditions to induce atrial stretch. Ca$\^$2+/ may be one of the most important factors affecting ANP secretion even though controversy still persists. The aim of the present study is to investigate the effect of lysophosphatidylcholines (LPCs) and moxonidine on atrial hemodynamics and ANP secretion in hypertrophied atria. LPC is an endogenous phospholipid released from cell membrane during ischemia, and moxonidine is a imidazoline 1 (Il) receptor agonoist.

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An Electronic Domain Chromatic Dispersion Monitoring Scheme Insensitive to OSNR Using Kurtosis

  • Kim, Kyoung-Soo;Lee, Jae-Hoon;Chung, Won-Zoo;Kim, Sung-Chul
    • Journal of the Optical Society of Korea
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    • v.12 no.4
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    • pp.249-254
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    • 2008
  • In this paper we present an electronic domain solution for chromatic dispersion (CD) monitoring algorithm based on the estimated time domain channel in electronic domain using channel estimation methods. The proposed scheme utilizes kurtosis as a CD measurement, directly computed from the estimated inter-symbol-interference (ISI) channel due to the CD distortion. Hence, the proposed scheme exhibits robust performance under OSNR variation, in contrast to the existing electronic domain approach based on minimum mean squared error (MMSE) fractionally-spaced equalizer taps [1]. The simulation results verify the CD monitoring ability of the proposed scheme.