• Title/Summary/Keyword: R-peak

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Effect of Pad Surface Characteristics on Within Wafer Non-uniformity in CMP (연마불균일도에 영향을 미치는 패드 표면특성에 관한 연구)

  • Park, Ki-Hyun;Park, Boum-Young;Kim, Hyoung-Jae;Jeong, Hae-Do
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.4
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    • pp.309-313
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    • 2006
  • Pad surface characteristics such as roughness, groove and wear rate of pad have a effect on the within wafer non-uniformity(WIWNU) in chemical mechanical polishing(CMP). Although WIWNU increases as the uniformity of roughness(Rpk: Reduced peak height) becomes worse in an early stage of polishing time, WIWNU decreases as non-uniformity of the Rpk value. Also, WIWNU decreases with the reduction of the pad stiffness, though original mechanical properties of pad are unchanged by the grooving process. In addition, conditioning process causes the inequality of pad wear during in CMP. The profile of pad wear generated by the conditioning process has a significant effect on the WIWNU. These experiments results could help to understand the effect of pad surface characteristics in CMP.

Die-Sinking Electrical Discharge Machining with Dielectric Fluid Ejection System through the Inside of the Electrode (전극봉내 방전유 분산시스템에 의한 형조방전기공)

  • 왕덕현;우정윤
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.1
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    • pp.71-77
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    • 2001
  • Experimental study if die-sinking electrical discharge machining(EDM) was conducted with rotating electrode system including inside hole for increasing the material removal rate(MRR). With the help of dielectric fluid flow through the inside according to the different internal diameter of the hole, the molten workpiece debris could be removed and flushed out during the EDM, Cold die alloy(SKD-1) was executed for different peak current and duty factor. From this study, the MRR was found to be increased with the peak current. The more MRR was obtained for the case of electrode inside diam-eter of 10 mm, but the MRR was decreased as the diameter near at the 4mm and 6mm. The values of surface roughness and roundness were analyzed under various conditions, and these were affected by the inside diameter change of electrode.

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A neural-attenuation model before Mexican extreme events

  • Garcia, Silvia R.;Alcantara, Leonardo
    • Earthquakes and Structures
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    • v.17 no.6
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    • pp.591-598
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    • 2019
  • The most recent shaking experiences have demonstrated that the predictions of the seismic models are not always in agreement with the registered responses, especially in the face of extreme earthquakes. Records collected from 1960 to 2011 at a rock-like site are used to develop a neural network that permits to estimate peak ground accelerations via the magnitude, the focal depth, the site-source distance and a seismogenic zone. The neural model is applied to the 8th and 19th September 2017 events that hit Mexican territory and the obtained results show that the network is flexible enough to work appropriately to various conditions of intensity and sites-sources with remarkably predictive capacity. The neural-attenuation curves are compared with those obtained from Ground Motion Prediction Equations and their performance is assessed for events, in addition to the devastating Mexican events, from Japan, Taiwan, Chile and USA.

A Design of LC-tuned Sinusoidal VCOs Using OTA-C Active Inductors

  • Chung, Won-Sup;Son, Sang-Hee
    • Journal of IKEEE
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    • v.11 no.3
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    • pp.122-128
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    • 2007
  • Sinusoidal voltage-controlled oscillators (VCOs) based on Colpitts and Hartley oscillators are presented. They consist of a LC parallel-tuned circuit connected in a negative-feedback loop with an OTA-R amplifier and two diode limiters, where the inductor is simulated one realized with temperature-stable linear operational transconductance amplifiers (OTAs) and a grounded capacitor. Prototype VCOs are built with discrete components. The Colpitts VCO exhibits less than 1% nonlinearity in its current-to-frequency transfer characteristic from 4.2 to 21.7 MHz and ${\pm}$95 ppm/$^{\circ}C$ temperature drift of frequency over 0 to $70^{\circ}C$. The total harmonic distortion (THD) is as low as 2.92% with a peak-to-peak amplitude of 0.7 V for a frequency-tuning range of 10.8-32 MHz. The Hartley VCO has the temperature drift and THD of two times higher than those of the Colpitts VCO.

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Design of Digital Voltage Regulation System for 200kW Engine-Generator (200kW급 엔진-발전기의 디지털 전압제어 시스템 설계)

  • Kim, Tae-Hyoung;Lee, Dong-Hee;Ahn, Jin-Woo
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.912-913
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    • 2008
  • In this paper, peak detector of generator output voltage and variable gain controller is introduced for the fast dynamic response. The general r.m.s. detecting signal of generator has inherent time delay from the actual signal. So the dynamic response of generator using conventional PID controller has some problem in sudden load change. In order to overcome this problem, the peak detector and signal selector with variable gain controller is used in this paper. The proposed control scheme is verified from experimental test of 200kW diesel engine-generator.

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Effect of the Substrate Temperature on the Copper Oxide Thin Films

  • Park, Ju-Yeon;Gang, Yong-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.71-71
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    • 2010
  • Copper oxide thin films were deposited on the p-type Si(100) by r.f. magnetron sputtering as a function of different substrate temperature. The deposited copper oxide thin films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The SEM and SE data show that the thickness of the copper oxide films was about 170 nm. AFM images show that the surface roughness of copper oxide films was increased with increasing substrate temperature. As the substrate temperature increased, monoclinic CuO (111) peak appeared and the crystal size decreased while the monoclinic CuO (-111) peak was independent on the substrate temperature. The oxidation states of Cu 2p and O 1s resulted from XPS were not affected on the substrate temperature. The contact angle measurement was also studied and indicated that the surface of copper oxide thin films deposited high temperature has more hydrophobic surface than that of deposited at low temperature.

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Experimental Study of DC Coronas in Point-to-Plane Short Gap (지간적 직류Corona의 실질적 검토)

  • 오철한;이성만
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.32 no.5
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    • pp.157-163
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    • 1983
  • Positive and negative coronas in point-to-plane short gap have been investigated with the variations of point radius and gap length. Mainly the onset potentials and current pulses under various conditions were measured with a 70 MHz C.R.O. and a precise-controllable D.C. power supply. In the case of negative corona, the Trichel pulse corona, glow corona and spark regions were distinguished apparently and the critical gap lengths between them were also found clearly. In the case of positive corona, there are streamer corona, spark regions and the critical gap length between them, too. The current pulse forms of Trichel pulse corona of negative and streamer pulse corona of positive are similar in rising time, peak-to-peak time and pulse width. The glow corona current shows D.C. component in form.

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A Current-mode peak detector circuit

  • Riewruja, V.;Linthong, A.;Kaewpoonsuk, A.;Guntapong, R.;Supaph, S.
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.512-512
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    • 2000
  • In this article, a current mode peak detector circuit is presented. The simple circuit configuration comprises four MOS transistors and one external capacitor. The realization method is suitable fur fabrication using CMOS technology and all transistors are operated in their saturation region. The proposed circuit exhibits a very low drop rate and provides high accuracy, high-speed and wide dynamic range. The proposed circuit has very low power dissipation and operates using a single 2.5V supply. Simulation results confirmed the characteristic of the proposed circuit are also included.

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Real time gait analysis using acceleration signal (가속도 신호를 이용한 실시간 보행 분석)

  • Kang, G.T.;Park, K.T.;Kim, G.R.;Choi, B.C.;Jung, D.K.
    • Journal of Sensor Science and Technology
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    • v.18 no.6
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    • pp.449-455
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    • 2009
  • In this paper, we developed a digital gait analyzer using the triaxial accelerometer(TA). An approach for normal gait detection employing decay slope peak detection(DSPD) algorithm was presented. The TA was attached to the center of the waist of a subject. The subject walked a bare floor at 60, 92 and 120 steps/minute. We analyzed vertical axis acceleration signal for gait detection. At 60, 92, 120 steps/minute walking, detection accuracy of gait events were over 99 % accuracy.

Effect of CaO Addition on Age Hardening Behavior of AZ91 Alloy (AZ91 합금의 시효경화 거동에 미치는 CaO 첨가의 영향)

  • Jun, Joong-Hwan
    • Journal of the Korean Society for Heat Treatment
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    • v.24 no.4
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    • pp.193-198
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    • 2011
  • Effect of CaO addition on age hardening response has been studied by using optical microscopy, scanning electron microscopy and differential thermal analysis in AZ91 and CaO-containing ECO-AZ91 alloys. After solution treatment, the ${\beta}$($Mg_{17}Al_{12}$) phase formed during solidification mostly disappeared in the microstructure in the AZ91 alloy, whereas numerous ${\beta}$ precipitates containing Ca were still observed in the ECO-AZ91 alloy due to its enhanced thermal stability. The ECO-AZ91 alloy showed the delayed peak aging time and higher peak hardness compared with those of the AZ91 alloy. The activation energies for ${\beta}$ precipitation calculated by means of Kissinger method increased from 71.4 to 85.6 kJ/mole by the addition of CaO, which implies that CaO plays a role in reducing ${\beta}$ precipitation rate in the AZ91 alloy.