• 제목/요약/키워드: reference pulse

검색결과 326건 처리시간 0.022초

H-브릿지 멀티레벨 인버터의 전압 지연 해석 및 전류 제어 보상 (Analysis of Voltage Delay and Compensation for Current Control in H-Bridge Multi-Level Inverter)

  • 박영민;유한승;이현원;정명길;이세현
    • 전력전자학회논문지
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    • 제15권1호
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    • pp.43-51
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    • 2010
  • 본 논문에서는 고전압 전동기 가변속 장치인 H-브릿지 멀티레벨(H-Bridge Multi-Level; HBML) 인버터를 이용한 유도 전동기 벡터 제어시 인버터의 출력 전압 위상 지연 현상을 해석하고 전류 제어기의 보상 기법을 제시하였다. Phase-Shifted Pulse Width Modulation (PSPWM) 기법을 적용한 HBML 인버터는 개별 인버터 모듈이 독립적으로 동작할 수 있어서 확장성과 모듈화 능력이 향상되는 장점이 있다. 그러나 이러한 PSPWM을 적용한 HBML 인버터는 기준 전압과 실제 전압 사이에 위상 차이가 있기 때문에 출력 주파수에 대한 샘플링 주파수의 비율이 충분하지 않은 고속 영역에서 전류 제어기를 불안정하게 하는 원인이 된다. 전류 제어기의 불안정성은 기준 전압과 출력 전압의 위상 차이를 보상하는 제안된 방법을 추가함으로써 제거하였다. 본 방법은 인버터의 스위칭 주파수가 낮고, 전동기 속도가 높은 조건에서 PSPWM을 이용한 HBML 인버터 시스템에 효과적이며, 13레벨로 구성된 HBML 인버터로 구동되는 6,600[V] 1,400[kW] 유도전동기 실험을 통해 제안된 방법의 타당성을 입증하였다.

광용적맥파 신호를 이용한 수면 중 호흡 추정 (Estimation of Respiration Using Photoplethysmograph During Sleep)

  • 박종욱;이전;이효기;김호중;이경중
    • 대한의용생체공학회:의공학회지
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    • 제34권3호
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    • pp.105-110
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    • 2013
  • Respiratory signal is one of the important physiological information indicating the status and function of the body. Recent studies have provided the possibility of being able to estimate the respiratory signal by using a change of PWV(pulse width variability), PRV(pulse rate variability) and PAV(pulse amplitude variability) in the PPG (photoplethysmography) signal during daily life. But, it is not clear whether the respiratory monitoring is possible even during sleep. Therefore, in this paper, we estimated the respiration from PWV, PRV and PAV of PPG signals during sleep. In addition, respiration rates of the estimated respiration signal were calculated through a time-frequency analysis, and errors between respiration rates calculated from each parameter and from reference signal were evaluated in terms of 1 sec, 10 sec and 1 min. As a result, it showed the errors in PWV(1s: $36.38{\pm}37.69$ mHz, 10s: $36.53{\pm}38.16$ mHz, 60s: $30.35{\pm}38.72$ mHz), in PRV(1s: $1.45{\pm}1.38$ mHz, 10s: $1.44{\pm}1.37$ mHz, 60s: $0.45{\pm}0.56$ mHz), and in PAV(1s: $1.05{\pm}0.81$ mHz, 10s: $1.05{\pm}0.79$ mHz, 60s: $0.56{\pm}0.93$ mHz). The errors in PRV and PAV are lower than that of PWV. Finally, we concluded that PRV and PAV are more effective than PWV in monitoring the respiration in daily life as well as during sleep.

『의학입문(醫學入門)』의 인용서적으로 살펴본 요통(腰痛)의 분류와 기준 (The Classification and Criterion for Low Back Pain Examined from Reference Books of Yi Xue Ru Men(醫學入門))

  • 조학준
    • 대한한의학원전학회지
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    • 제28권1호
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    • pp.35-53
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    • 2015
  • Objectives : In order to find how reference books of Yi Xue Ru Men reflect the classification and criterion for low back pain(LBP). Methods : From reference books of Yi Xue Ru Men, select the texts on classification and criterion for LBP. Results : According to the causes of LBP, Chao Yuan Fang(巢元方) in Sui Dynasty assorted to 5 types of LBP at the very first. Chen Wu Ze(陳無擇) in Song Dynasty made 7 divisions by external, internal, and non-external, non-internal causes. According to the pulse of LBP, Yan Yong He(嚴用和) first categorized 4 groups, Zhu Zhen Heng(朱震亨) added another 4 groups. Aside from this standard, Zhu(朱震亨) adopted the cause standard. Depending on Yunqi(運氣), Lou Ying(樓英) classified 5 types. But his classification had been not adopted by any TCM books. According to symptom of 6 varieties(六變), Zhang Jie Bin(張介賓) assorted external(表), internal(裏), deficiency(虛), sufficiency(實), cold(寒) and heat(熱), add 2 groups besides them. But his categorization did not reflect Yi Xue Ru Men. Li Chan(李梴), the author of this book chose causes and pulse classification standards that Zhu Zhen Heng had adopt. Conclusions : In the side of classification and criterion for LBP, Li Chan first divided 2 group, external and internal injury. After it he subdivided both groups to 10 subgroup. His classification is similar to Chen(陳無擇)'s, but actually followed the classification for external and internal injury that was invented by Li Dong Yuan(李東垣).

맥파 전달 속도(PWV) 측정을 위한 특징점 검출 알고리즘 개발 (Development of Feature Points Detection Algorithm for Measuring of Pulse Wave Velocity)

  • 최정현;조욱현;박준호;김남훈;성향숙;조종만
    • 센서학회지
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    • 제20권5호
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    • pp.343-350
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    • 2011
  • The compliance and stiffness of artery are closely related with disease of arteries. Pulse wave velocity(PWV) in the blood vessel is a basic and common parameter in the hemodynamics of blood pressure and blood flow wave traveling in arteries because the PWV is affected directly by the conditions of blood vessels. However, there is no standardized method to measure the PWV and it is difficult to measure. The conventional PWV measurement has being done by manual calculation of the pulse wave transmission time between coronary arterial proximal and distal points on a strip chart on which the pulse wave and ECG signal are recorded. In this study, a pressure sensor consisting of strain gauges is used to measure the blood pressure of arteries in invasive method and regular ECG electrodes are used to record the ECG signal. The R-peak point of ECG is extracted by using a reference level and time windowing technique and the ascending starting point of blood pressure is determined by using differentiation of the blood pressure signal and time windowing technique. The algorithm proposed in this study, which can measure PWV automatically, shows robust and good results in the extraction of feature points and calculation of PWV.

광디스크 드라이브에서 ref_T. E신호 와 샘플펄스 신호를 이용한 평균 탐색시간 개선에 관한 연구 (A study on the improvement of average seek time which use ref_T. E signal and sample pulse signal in optical disk drive)

  • 이시현;김계국;김형래
    • 한국음향학회지
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    • 제14권4호
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    • pp.5-11
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    • 1995
  • 본 논문에서는 광디스크 드라이브가 디스크상의 데이터를 탐색하는데 소요되는 평균탐색 시간 (Average Seek Time)을 개선하기 위한 방법으로 트랙추적 기준신호 (ref_T. E)와 샘플펄스 신호를 사용하여 평균탐색시간을 줄일수 있는 새로운 알고리즘을 제안 하였다. ref_T. E신호와 샘플펄스 신호를 사용하여 트랙을 탐색할 경우 목적트랙으로 이동한 다음 다시 위치를 확인하고 보상할 필요가 없도록하여 평균탐색시간을 개선하였다. 실험결과 28sec의 평균탐색시간을 보였다.

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A New DPWM Method to Suppress the Low Frequency Oscillation of the Neutral-Point Voltage for NPC Three-Level Inverters

  • Lyu, Jianguo;Hu, Wenbin;Wu, Fuyun;Yao, Kai;Wu, Junji
    • Journal of Power Electronics
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    • 제15권5호
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    • pp.1207-1216
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    • 2015
  • In order to suppress the low frequency oscillation of the neutral-point voltage for three-level inverters, this paper proposes a new discontinuous pulse width modulation (DPWM) control method. The conventional sinusoidal pulse width modulation (SPWM) control has no effect on balancing the neutral-point voltage. Based on the basic control principle of DPWM, the relationship between the reference space voltage vector and the neutral-point current is analyzed. The proposed method suppresses the low frequency oscillation of the neutral-point voltage by keeping the switches of a certain phase no switching in one carrier cycle. So the operating time of the positive and negative small vectors is equal. Comparing with the conventional SPWM control method, the proposed DPWM control method suppresses the low frequency oscillation of the neutral-point voltage, decreases the output waveform harmonics, and increases both the output waveform quality and the system efficiency. An experiment has been realized by a neutral-point clamped (NPC) three-level inverter prototype based on STM32F407-CPLD. The experimental results verify the correctness of the theoretical analysis and the effectiveness of the proposed DPWM method.

Nafion-Tetren-Glycerol이 수식된 유리탄소전극에서 납(II) 이온의 정량 (Determination of Lead(II) at Nation-Coated Glassy Carbon Electrodes Modified by Tetren-Glycerol)

  • 반옥기;박은희;정근호
    • 한국환경보건학회지
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    • 제29권2호
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    • pp.62-68
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    • 2003
  • Differential pulse voltammetry (DPV) using nafion-coated glassy carbon electrodes modified with Tetren(tetraethylene pentamine)-glycerol showed sensitivity for determining lead (II) at low concentration. The Lead (II) was accumulated on the electrode surface by the formation of the complex in an open circuit, and the resulting surface was characterized by medium exchange, electrochemical reduction, and differential pulse voltammetry. Various experimental parameters, such as the composition of modifier, preconcentration time, pH of electrolyte (0.1 M acetate buffer), and parameters of differential pulse voltammetry, were optimized. The initial potential was applied for 50 s, the electrode was scanned from -0.9 to -0.3 V, and the anodic peak current was measured at -0.604 V $\pm$ 0.015 V (vs. Ag/AgCl). The calibration plot was obtained in the range 1.0$\times$10$^{-8}$ M~l.0$\times$10$^{-6}$ M with pH 4.5 buffer solution. The detection limit (3$\sigma$) it as low as 5.0$\times$ 10$^{-9}$ M. This method is applied to the determination of lead(II) in a certified reference material and the result agrees satisfactorily with the certified value.

Comparison of Clinical Laboratory Data and Prevalence according to Arterial Stiffness in Stroke Patients

  • Jin, Bok Hee;Han, Min Ho
    • 대한임상검사과학회지
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    • 제46권4호
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    • pp.143-149
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    • 2014
  • Pulse wave velocity (PWV) is used to non-invasively estimate the severity of arteriosclerosis by measuring the patient's arterial stiffness comparing with each normal reference range according to their ages. Increased arterial stiffness is closely related to both atherosclerosis and arteriosclerosis, which have been known for causes of cardiovascular disease and stroke, also negatively affects the prognosis and the re-occurrence in patients with stroke. The study is focused on how brachial-ankle pulse wave velocity (baPWV) is related to cardiovascular disease risk factors in patients with acute stroke. There were 114 subjects, 69 males and 45 females, all in their 60's and had PWV test for acute stroke. The results are as follows: the group with increased arterial stiffness showed significant increase in HbAlc, total cholesterol, RSBP (resting systolic blood pressure), CSBP (central systolic blood pressure) and CDBP (central diastolic blood pressure). Cross tabulation test showed that there was a significant relationship only between the group with increased arterial stiffness and diabetes mellitus (DM). Therefore, it might be useful for preventing re-occurrence and making a favorable prognosis to promptly adjust DM and hypertension-related risk factors in patients with acute stroke.

Analysis and Implementation of PS-PWAM Technique for Quasi Z-Source Multilevel Inverter

  • Seyezhai, R.;Umarani, D.
    • Journal of Electrical Engineering and Technology
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    • 제13권2호
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    • pp.688-698
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    • 2018
  • Quasi Z-Source Multilevel Inverter (QZMLI) topology has attracted grid connected Photovoltaic (PV) systems in recent days. So there is a remarkable research thrust in switching techniques and control strategies of QZMLI. This paper presents the mathematical analysis of Phase shift- Pulse Width Amplitude Modulation (PS-PWAM) for QZMLI and emphasizes on the advantages of the technique. The proposed technique uses the maximum and minimum envelopes of the reference waves for generation of pulses and proportion of it to generate shoot-through pulses. Hence, it results in maximum utilization of input voltage, lesser switching loss, reduced Total Harmonic Distortion (THD) of the output voltage, reduced inductor current ripple and capacitor voltage ripple. Due to these qualities, the QZMLI with PS-PWAM emerges to be the best suitable for PV based grid connected applications compared to Phase shift-Pulse Width Modulation (PS-PWM). The detailed math analysis of the proposed technique has been disclosed. Simulation has been performed for the proposed technique using MATLAB/Simulink. A prototype has been built to validate the results for which the pulses were generated using FPGA /SPARTAN 3E.

DSP를 이용한 직접구동형 AC모터 위치제어기의 설계 (Design of Direct Drive AC Motor Position Controller Using DSP)

  • 박성언;김갑일;이광무;이창섭;장태성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 B
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    • pp.846-848
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    • 1995
  • Recently, direct drive AC servo motor and DSP is widely used in the factory automation and related field due to the enhanced control and digital technology. In this paper, position control of direct drive AC servo motor and numerical interpolation algorithms are studied using DSP for the future applications. In the direct drived motor control, encoder pulse is divided into the quadruple pulse for the higher resolution and high speed pulse(10MHz) is used as reference for the slower speed motor control (M/T method). As for the general position control, PI controller is adapted for position control. In the trajectory tracking numerical algorithm, interpolation of straight line and curve algorithms are studied for the realization of path following capabilities of XY table. As for the DSP, ADSP 2105 is selected for the economy and performance points of view.

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