• 제목/요약/키워드: Improved linearity

검색결과 233건 처리시간 0.022초

디지털 신호처리기를 이용한 고분해능 온도측정 시스템 설계 (A Design of High Resolution Temperature Measurement System Using Digital Signal Processor)

  • 김태훈;임주현;김덕영;고한우;김성환
    • 대한전기학회논문지:시스템및제어부문D
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    • 제51권7호
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    • pp.317-322
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    • 2002
  • This paper presents a linear temperature/voltage relation over a temperature range(0~100$^{\circ}C$) with high-resolution, reasonably god response linearity, reliability, and overall improved performance. A notable feature of the proposed method is that the whole temperature span is divided by 16 subbands thus the variation span of measured voltage is narrowed. Therefore noise characteristic has been improved. The output voltage is amplified after the uniformed DC voltage component is eliminated by offset. We proposed circuit using median value and mean value of digital signal in order to reduce the noise effect. The proposed circuit offers linear temperature/voltage conversion over a wide dynamic range using DSP(TMS320C31) and steinhart equation.

Improved Direct Torque Control for Sensorless Matrix Converter Drives with Constant Switching Frequency and Torque Ripple Reduction

  • Lee Kyo-Beum;Blaabjerg Frede
    • International Journal of Control, Automation, and Systems
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    • 제4권1호
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    • pp.113-123
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    • 2006
  • In this paper, an improved direct torque control (DTC) method for sensorless matrix converter drives is proposed which enables to minimize torque ripple, to obtain unity input power factor, and to achieve good sensorless speed-control performance in the low speed operation, while maintaining constant switching frequency and fast torque dynamics. It is possible to combine the advantages of matrix converters with the advantages of the DTC strategy using space vector modulation and a flux deadbeat controller. To overcome the phase current distortion by the non-linearity of a matrix converter drive, the simple non-linearity compensation method using PQR power theory are presented in the proposed scheme. Experimental results are shown to illustrate the feasibility of the proposed strategy.

Feedback Loop Design for Micro Gyroscope

  • Sung, Woon-Tahk;Song, Jin-Woo;Lee, Jang-Gyu;Taesam Kang
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.39.4-39
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    • 2002
  • This paper presents a design and implementation of a PID feedback control loop for micro gyroscope. The feedback control loop improves the gyroscope performance such as linearity, bandwidth, and bias stability for micro gyroscope which is basically a high-Q system and exhibits a low performance with an open loop control. The designed and implemented feed-back control loop is applied to the SNU-Bosch MEMS gyroscope to demonstrate the improvement with the feedback control loop. The bandwidth is improved to 60Hz from 25Hz of open loop control. The linearity becomes 0.5% from 1%. The bias stability is improved to 0.03 deg/sec from 0.06 deg/sec.

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자기센서를 이용한 위치추정 정밀도 향상 방안에 관한 연구 (A Study on the Method for Improving the Localization Accuracy using the Magnetic Sensors)

  • 김정태;김무선;홍재성
    • 한국정밀공학회지
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    • 제31권2호
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    • pp.133-139
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    • 2014
  • Magnetic Sensors can be employed to localize the unmanned vehicle which is running a predefined path where magnets are embedded for certain spaces. Among various sensor types, sensor arrays of 1-dimensional magnetic sensor have the merit of easy elimination of external magnetic component such as terrestrial magnetism. However, interpolation should be considered in the array sensors in order to increase the precision level because there is a limit in arranging sensors in close interval. We propose the novel interpolation method which can be performed with simple computation and represents the improved accuracy by increasing the linearity of the interaction formula. Demonstration of the linearity and simulation results show the proposed method exhibits the improved accuracy compared to the conventional method.

dB-선형적 특성을 가진 GPS 수신기를 위한 CMOS 가변 이득 증폭기 (dB-Linear CMOS Variable Gain Amplifier for GPS Receiver)

  • 조준기;유창식
    • 대한전자공학회논문지SD
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    • 제48권7호
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    • pp.23-29
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    • 2011
  • 본 논문에서는 GPS 수신기를 위한 dB-선형 특성이 개선된 가변 이득 증폭기 회로를 제안한다. 제안된 dB-선형 전류 발생기는 dB-선형성 오차가 ${\pm}0.15$dB 이내로 개선되었다. 개선된 dB-선형 전류 발생기를 사용하여 GPS 수신기를 위한 가변 이득 증폭기를 설계였다. GPS 수신기의 IF 주파수는 4MHz를 가정하였고, 선형성 요구조건을 도출하여 만족하기 위해 최소 이득일때 24dBm의 IIP3를 만족하도록 하였다. 가변이득 증폭기는 3단으로 구성되어 있으며 DC-오프셋 제거 루프를 통하여 회로의 오프셋 전압을 보상하였다. 설계된 가변 이득 증폭기의 이득은 -8dB~52dB의 범위를 가지며 이득의 dB-선형성은 ${\pm}0.2$dB 이내를 충족한다. 3-dB 주파수 대역폭은 이득에 따라 35MHz~106MHz를 보인다. 가변 이득 증폭기는 CMOS 0.18${\mu}m$ 공정을 이용하여 설계되었으며 전력은 1.8V 전원 전압에서 3mW를 소비한다.

MLP 층을 갖는 CNN의 설계 (Design of CNN with MLP Layer)

  • 박진현;황광복;최영규
    • 한국기계기술학회지
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    • 제20권6호
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    • pp.776-782
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    • 2018
  • After CNN basic structure was introduced by LeCun in 1989, there has not been a major structure change except for more deep network until recently. The deep network enhances the expression power due to improve the abstraction ability of the network, and can learn complex problems by increasing non linearity. However, the learning of a deep network means that it has vanishing gradient or longer learning time. In this study, we proposes a CNN structure with MLP layer. The proposed CNNs are superior to the general CNN in their classification performance. It is confirmed that classification accuracy is high due to include MLP layer which improves non linearity by experiment. In order to increase the performance without making a deep network, it is confirmed that the performance is improved by increasing the non linearity of the network.

Linearity-Distortion Analysis of GME-TRC MOSFET for High Performance and Wireless Applications

  • Malik, Priyanka;Gupta, R.S.;Chaujar, Rishu;Gupta, Mridula
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제11권3호
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    • pp.169-181
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    • 2011
  • In this present paper, a comprehensive drain current model incorporating the effects of channel length modulation has been presented for multi-layered gate material engineered trapezoidal recessed channel (MLGME-TRC) MOSFET and the expression for linearity performance metrics, i.e. higher order transconductance coefficients: $g_{m1}$, $g_{m2}$, $g_{m3}$, and figure-of-merit (FOM) metrics; $V_{IP2}$, $V_{IP3}$, IIP3 and 1-dB compression point, has been obtained. It is shown that, the incorporation of multi-layered architecture on gate material engineered trapezoidal recessed channel (GME-TRC) MOSFET leads to improved linearity performance in comparison to its conventional counterparts trapezoidal recessed channel (TRC) and rectangular recessed channel (RRC) MOSFETs, proving its efficiency for low-noise applications and future ULSI production. The impact of various structural parameters such as variation of work function, substrate doping and source/drain junction depth ($X_j$) or negative junction depth (NJD) have been examined for GME-TRC MOSFET and compared its effectiveness with MLGME-TRC MOSFET. The results obtained from proposed model are verified with simulated and experimental results. A good agreement between the results is obtained, thus validating the model.

뉴로모픽 시스템 향상을 위한 RRAM 기반 시냅스 소자 리뷰 (A Review of RRAM-based Synaptic Device to Improve Neuromorphic Systems)

  • 박건우;김제규;최건우
    • 반도체디스플레이기술학회지
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    • 제21권3호
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    • pp.50-56
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    • 2022
  • In order to process a vast amount of data, there is demand for a new system with higher processing speed and lower energy consumption. To prevent 'memory wall' in von Neumann architecture, RRAM, which is a neuromorphic device, has been researched. In this paper, we summarize the features of RRAM and propose the device structure for characteristic improvement. RRAM operates as a synapse device using a change of resistance. In general, the resistance characteristics of RRAM are nonlinear and random. As synapse device, linearity and uniformity improvement of RRAM is important to improve learning recognition rate because high linearity and uniformity characteristics can achieve high recognition rate. There are many method, such as TEL, barrier layer, NC, high oxidation properties, to improve linearity and uniformity. We proposed a new device structure of TiN/Al doped TaOx/AlOx/Pt that will achieve high recognition rate. Also, with simulation, we prove that the improved properties show a high learning recognition rate.

마이크로파 거리계의 VCO 비선형성에 의한 시스템 특성 분석 및 개선 방안 연구 (Improved Design of the Microwave Level Meter upon VCO Nonlinearity)

  • 전중창;김정목임종수
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.331-334
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    • 1998
  • In this paper, we have presented an improved design of the microwave level meter based on the principle of FM-CW radar. First, we have analyzed the effect of VCO nonlinearity on the spectral broadening of the beat signal, and presented a new type of design theory to linearize VCO tuning curve adopting FFT algorithm. Simulation results for a VCO having the linearity of 25% have been presented, which show the usefulness of the design algorithm.

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AN IMPROVED LOWER BOUNDS OF UNIVARIATE BONFERRONI-TYPE INEQUALITY

  • Lee, Min-Young;Jo, Moon-Shik
    • 충청수학회지
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    • 제22권2호
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    • pp.171-175
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    • 2009
  • Let $A_1,\;A_2,\;{\cdots},\;A_n$ be a sequence of events on a given probability space. Let $m_n$ be the number of those $A_{i}{^{\prime}}s$ which occur. We establish an improved lower bounds of Univariate Bonferroni-Type inequality by using the linearity of binomial moments $S_1,\;S_2,\;S_3,\;S_4$ and$S_5$.

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