• Title, Summary, Keyword: Waveform

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A Study of Negative Waveform in ac PDP during Reset and Address Periods (ac PDP에서의 Reset과 Address 구간에서 Negative Waveform특성에 관한 연구)

  • Eom, Cheol-Hwan;Kang, Jung-Won
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.1
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    • pp.27-31
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    • 2009
  • A characteristic of new waveform, called a negative waveform, was studied during reset and address periods. IR distribution, black luminance and time delay were measured to compare the negative waveform with the conventional positive waveform. Based on the analysis of IR measurement, the negative waveform could accumulate more wall charges than the positive waveform. Also the black luminance of negative waveform was lower than that of positive waveform under the same bias and ramp-slope conditions. During address period, the discharge time lag was measured. The negative waveform was showed 0.25 us faster formative time lag and 0.1 us faster average time lag than those of positive waveform.

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Characteristic of a Negative Driving Waveform in ac PDPs

  • Kang, Jung-Won
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.97-100
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    • 2009
  • A negative waveform was studied to improve the driving characteristics of reset and address periods in ac PDP. Comparative experiments between negative and conventional positive waveforms were performed with 42-inch XGA PDP module. The negative waveform showed lower breakdown voltage than the conventional positive waveform in reset period. Due to its weak and stable discharge during reset period, the contrast ratio was improved by decreasing the black luminance. During address period, the discharge time-lag was measured. The formative time lag ($=T_f$) of negative waveform was improved about 22.8% than $T_f$ of conventional positive waveform.

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Simulation of the Blood Pressure Estimation Using the Artery Compliance Model and Pulsation Waveform Model

  • Jeon, Ahyoung;Ro, Junghoon;Kim, Jaehyung;Baik, Seongwan;Jeon, Gyerok
    • Journal of Sensor Science and Technology
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    • v.22 no.1
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    • pp.38-43
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    • 2013
  • In this study, the artery's compliance model and the pulsation waveform model was proposed to estimate blood pressure without applying HPF (High Pass Filter) on signal measured by the oscillometric method. The method proposed in the study considered two ways of estimating blood pressure. The first method of estimating blood pressure is by comparing and analyzing changes in pulsation waveform's dicrotic notch region during each cardiac period. The second method is by comparing and analyzing morphological changes in the pulsation waveform during each cardiac period, which occur in response to the change in pressure applied on the cuff. To implement these methods, we proposed the compliance model and the pulsation waveform model of the artery based on hemodynamic theory, and then conducted various simulations. The artery model presented in this study only took artery's compliance into account. Then, a pulsation waveform model was suggested, which uses characteristic changes in the pulsation waveform to estimate blood pressure. In addition, characteristic changes were observed in arterial volume by applying artery's pulsation waveform to the compliance model. The pulsation waveform model was suggested to estimate blood pressure using characteristic changes of the pulsation waveform in the arteries. This model was composed of the sum of sine waves and a Fourier's series in combination form up to 10th harmonics components of the sinusoidal waveform. Then characteristic of arterial volume change was observed by inputting pulsation waveform into the compliance model. The characteristic changes were also observed in the pulsation waveform by mapping the arterial volume change in accordance with applied cuff's pressure change to the pulsation waveform's change according to applied pressure changes by cuff. The systolic and diastolic blood pressures were estimated by applying positional change of pulsation waveform's dicrotic notch region.

An Experimental Study on the Effect of Troubles of Solenoid Injector on Fuel Injection Quantity of CRDI Diesel Vehicle (CRDI 디젤 엔진의 솔레노이드 인젝터 불량이 연료 분사량에 미치는 영향에 관한실험적 연구)

  • Kang, Sung-Gu;Yoo, Jong-Sik;Kim, Chul-Soo
    • Journal of the Korean Society of Mechanical Technology
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    • v.19 no.6
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    • pp.809-814
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    • 2017
  • This paper investigates the relationship between the waveform area and fuel injection quantity. It is on developing on analysis method of waveform the effect of waveform area on fuel injection quantity of CRDI Diesel engine. The experimental methods using Pico oscilloscope and fuel injection tester are employed to measure current and voltage waveform and fuel injection quantity of solenoid injector. The one normal and two abnormal solenoid injectors are used. The experiment is carried out during no-load condition. A summary of the important results are as follows. 1) The area of the voltage and current waveform of the abnormal injector becomes larger than the that of normal injector, and the area of the current and voltage waveform is inversely proportional to the fuel injection quantity. 2) The area of the current waveform can be obtained more accurate results than that of voltage waveform. 3) It is possible to infer the fuel injection quantity by measuring the current waveform and calculating the area.

Comparative Studies between the Negative Waveform and the Conventional Positive Waveform during Reset Period.

  • Eom, Cheol-Hwan;Lim, Hyun-Muk;Lee, Jun-Young;Kong, Byoung-Goo;Park, Hyun-Il;Moon, Sung-Hak;Kang, Jung-Won
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.388-391
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    • 2008
  • A new reset waveform with negative ramp pulse was proposed. Comparative experiments between the negative and positive waveforms were performed. During reset period, IR distributions and luminance of black and white conditions were measured with the 42-inch XGA PDP module. The negative waveform improved contrast ratio about 15.4 ~ 22.5 % than the positive waveform by lowing the black luminance in reset period. Z bias (= Vbb) of the positive waveform was 27 V higher than the negative waveform.

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A Sequential LiDAR Waveform Decomposition Algorithm

  • Jung, Jin-Ha;Crawford, Melba M.;Lee, Sang-Hoon
    • Korean Journal of Remote Sensing
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    • v.26 no.6
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    • pp.681-691
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    • 2010
  • LiDAR waveform decomposition plays an important role in LiDAR data processing since the resulting decomposed components are assumed to represent reflection surfaces within waveform footprints and the decomposition results ultimately affect the interpretation of LiDAR waveform data. Decomposing the waveform into a mixture of Gaussians involves two related problems; 1) determining the number of Gaussian components in the waveform, and 2) estimating the parameters of each Gaussian component of the mixture. Previous studies estimated the number of components in the mixture before the parameter optimization step, and it tended to suggest a larger number of components than is required due to the inherent noise embedded in the waveform data. In order to tackle these issues, a new LiDAR waveform decomposition algorithm based on the sequential approach has been proposed in this study and applied to the ICESat waveform data. Experimental results indicated that the proposed algorithm utilized a smaller number of components to decompose waveforms, while resulting IMP value is higher than the GLA14 products.

Comparative study for height accuracy of Full waveform LiDAR data (Full waveform LiDAR의 높이 정확도 비교 분석)

  • Ryu, Joong-Hi;Lee, Jae-Hwan;Koh, Seung-Bum;Kim, Back-Seok;Seo, Hae-Soo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.3
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    • pp.257-263
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    • 2011
  • There are many previous researches such as verification of accuracy, application, and change detection of discrete return LiDAR data, but no researches for full waveform LiDAR data. In this study, we selected the forest area and urban area as case study areas and compared the height accuracy of full waveform LiDAR data with field surveying data. As a result, we got an RMSE of 3.lcm in urban area, 4.7cm in forest area, and it is verified that height accuracy of full waveform LiDAR is high. We think that it is very usefull in aerial photogrammetry.

A study on fatigue crack growth with loading waveform and analysis method for all loading waveform at elevated temperature in SUS 304 stainless steel (SUS 304강의 하중파형에 따른 고온피로균열전파속도 및 전체하중파형의 평가방법의 연구)

  • 이상록;이학주;허정원;임만배
    • Journal of Ocean Engineering and Technology
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    • v.6 no.1
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    • pp.122-130
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    • 1992
  • The effect of loading waveform on elevated temperature low-cycle fatigue crack growth behavior in a SUS 304 stainless steel have been investigated under symmetrical trangular (fast-fast), trapezoidal and asymmetrical(fast-slow, slow-fast) waveforms at 650.deg. C. It was found that the crack growth rate in fast-slow loading waveform appeared to be higher a little and the crack growth rate in slow-fast loading waveform much higer than that in fast-fast loading waveform, and difference in crack growth rate between fast-show and slow-fast waveforms nearly didn't appear in the region of da/dN>10/sup -2/ The crack growth rate in the trapezoidal loading waveform with t/sub h/=500sec appeared to be faster than that in slow(500sec)-fast(1sec). In addition, parameter modified J-integral could be considered as useful parameter for fatigue crack growth rate in all waveforms. The result obtained are as follow. da/dN=4.91*10/sup -3/ (.DELTA. J/sub c/)/sup 0.565/.

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A New Single Sustain Waveform with Auxiliary Address Pulse in ac PDP

  • Park, Woong-Hee;Lim, Hyun-Muk;Lee, Jun-Young;Kang, Jung-Won
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.392-395
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    • 2008
  • To improve the luminance in ac PDP, a new single sustain waveform with auxiliary address pulse is proposed. The new single sustain waveform was examined with 2 dimensional fluid codes and related experiments were performed with 42-inch XGA PDP module. At the same sustain level (= 180 V), the new waveform showed 3.6 times higher IR emission than the general waveform without auxiliary address pulse.

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Arbitrary Waveform Generation via Spectral Line-by-Line Pulse Shaping on Mode-Locked Pulses

  • Seo, Dong-Sun;Jiang, Zhi;Weiner, Andrew M.
    • Journal of IKEEE
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    • v.10 no.2
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    • pp.116-122
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    • 2006
  • We have built a grating-based, high-resolution, spectral line-by-line pulse shaper. By controlling individual spectral lines of a mode-locked laser output, we demonstrate the interesting functionalities of the pulse shaper for arbitrary waveform generation, such as width tunable pulse generation, phase controlled waveform generation, microwave waveform generation, etc.

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