• Title/Summary/Keyword: Vector Reduce

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Multi-level Vector Error Diffusion for Smear Artifact Reduction in the Boundary Regions (경계 영역에서 색 번짐 감소를 위한 멀티레벨 벡터 오차 확산법)

  • 박태용;조양호;김윤태;하영호
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.461-464
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    • 2003
  • This paper proposes the multi-level vector error diffusion for smear artifact reduction in the boundary regions. Smear artifact mainly results from a large accumulation of quantization error. Accordingly, to reduce these artifacts, the proposed method excludes the large quantization error in the error diffusion process by comparing the magnitude of the error vector with predetermined first threshold. In addition, if the vector norm of the difference between the error adjusted input vector and the primary co]or that has minimum vector norm for the error adjusted input vector is larger than second threshold, the error is excluded. As a result, the proposed method reduce smear artifact in the boundary region and produces visually pleasing halftone pattern.

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A Test Vector Reordering for Switching Activity Reduction During Test Operation Considering Fanout (테스트시 스위칭 감소를 위해 팬 아웃을 고려한 테스트벡터 재 정렬)

  • Lee, Jae-Hoon;Baek, Chul-Ki;Kim, In-Soo;Min, Hyoung-Bok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.1043-1048
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    • 2011
  • Test vector reordering is a very effective way to reduce power consumption during test application. But, it is time-consuming and complicated processes, and it does not consider internal circuit structure, which may limit the effectiveness. In this paper, we order test vectors using fanout count of primary inputs that consider the internal circuit structure, which may reduce the switching activity. Then, we reorder test test vectors again by using Hamming distance between test vectors. We proposed FOVO algorithm to perform these two ideas. FOVO is an effective way to reduce power consumption during test application. The algorithm is applied to benchmark circuits and we get an average of 3.5% or more reduction of the power consumption.

Vector Controlled Inverter for Elevator Drive (ELEVATOR 구동용 VECTOR 제어 인버터)

  • Shin, H.J.;Jang, S.Y.;Lee, S.J.;Lee, S.D.
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.627-630
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    • 1991
  • This study is about vector controlled inverter for high quality elevator drive that is to improve the settling accuracy of elevator car and passenger's comfort in commercial buildings. In this study, an instantaneous space vector control type inverter was used to reduce the torque ripple ant to improve the velocity follow-up. This method calculates Instantaneous actual output torque and flux of induction motor by voltage and current, then compares them with a reference values by a speed regulator. The outputs of comparators select a switching mode, for an optimal voltage vector. Also, this study used IGBT (Insulated Gate Bipolar-Transistor), a high speed switching element, to reduce sound noise level, and DSP (Digital Signal Processor) was used to improve the reliability of the control circuit by fully digitalization.

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Pixel decimation for block motion vector estimation (블록 움직임 벡터의 검출을 위한 화소 간축 방법에 대한 연구)

  • Lee, Young;Park, Gwi-Tae
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.9
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    • pp.91-98
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    • 1997
  • In this paper, a new pixel decimation algorithm for the estimation of motion vector is proposed. In traditional methods, the computational cost can be reduced since only part of the pixels are used for motion vector calculation. But these methods limits the accuracy ofmotion vector because of the same reason. We derive a selection criteria of subsampled pixels that can reduce the probablity of false motion vector detection based on stochastic point of view. By using this criteria, a new pixel decimation algorithm that can reduce the prediction error with similar computational cost is presented. The simulation results applied to standard images haveshown that the proposed algorithm has less mean absolute prediction error than conventional pixel decimation algorithm.

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Double-Objective Finite Control Set Model-Free Predictive Control with DSVM for PMSM Drives

  • Zhao, Beishi;Li, Hongmei;Mao, Jingkui
    • Journal of Power Electronics
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    • v.19 no.1
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    • pp.168-178
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    • 2019
  • Discrete space vector modulation (DSVM) is an effective method to improve the steady-state performance of the finite control set predictive control for permanent magnet synchronous motor drive systems. However, it requires complex computations due to the presence of numerous virtual voltage vectors. This paper proposes an improved finite control set model-free predictive control using DSVM to reduce the computational burden. First, model-free deadbeat current control is used to generate the reference voltage vector. Then, based on the principle that the voltage vector closest to the reference voltage vector minimizes the cost function, the optimal voltage vector is obtained in an effective way which avoids evaluation of the cost function. Additionally, in order to implement double-objective control, a two-level decisional cost function is designed to sequentially reduce the stator currents tracking error and the inverter switching frequency. The effectiveness of the proposed control is validated based on experimental tests.

Fast LBG Algorithm to Reduce the Computational Complexity

  • Kim Dong-Hyun;Kang Chul-Ho
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.4E
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    • pp.123-127
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    • 2005
  • In this paper, we propose a new method for reducing the number of distance calculations in the LBG (Linde, Buzo, Gray) algorithm, which is widely used method to construct a codebook in vector quantization of speech recognition system. The proposed algorithm can reduce the distance calculation between input vector and codeword by utilizing the observation that codewords are quickly stabilized as the number of iteration increases. From the simulation results, it is shown that we can reduce the running times over $43.77\%$ on average in comparison with current LBG algorithm without sacrificing the performance of codebook.

A New Reduced Common-mode Voltage SVM Method for Indirect Matrix Converters with Output Current Ripple Minimization

  • Tran, Quoc-Hoan;Lee, Hong-Hee
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.383-384
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    • 2015
  • This paper presents a new space vector modulation (SVM) method for indirect matrix converters (IMCs) to reduce commonmode voltage as well as minimize output current ripple in a high voltage transfer ratio. In the proposed SVM, the three-vector modulation scheme is used in the rectifier stage, while the nonzero state modulation technique, where the three nearest active vectors are selected to synthesize the desired output voltage, is applied to inverter stage to reduce the CMV. The proposed SVM method can significantly reduce the output current ripple and common-mode voltage of the IMC without any extra hardware. Simulated results are provided to demonstrate the effectiveness of the proposed SVM method.

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Efficient Motion Refinement Algorithm based on ASW for Reduced Frame-Rate Video Transcoder (시간해상도 감소 트랜스코딩을 위한 ASW움직임벡터 정밀화 알고리즘에 관한 연구)

  • 서동완;권혁민;최윤식
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.2044-2047
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    • 2003
  • In this paper, we propose efficient motion vector refinement algorithm for frame-rate reduction transcoding. The proposed algorithm is to set the search range for motion refinement based on the incoming motion vector. The algorithm calculates the importance of motion vector of the skipped frame and then selects two motion vector to set search range. Through this process, we determine the accuracy of incoming motion vector and set the search range lot refinement adaptively by means of the accuracy. In experiments, we show efficiency of our algorithm to reduce the search points for refinement.

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Concept Drift Based on CNN Probability Vector in Data Stream Environment

  • Kim, Tae Yeun;Bae, Sang Hyun
    • Journal of Integrative Natural Science
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    • v.13 no.4
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    • pp.147-151
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    • 2020
  • In this paper, we propose a method to detect concept drift by applying Convolutional Neural Network (CNN) in a data stream environment. Since the conventional method compares only the final output value of the CNN and detects it as a concept drift if there is a difference, there is a problem in that the actual input value of the data stream reacts sensitively even if there is no significant difference and is incorrectly detected as a concept drift. Therefore, in this paper, in order to reduce such errors, not only the output value of CNN but also the probability vector are used. First, the data entered into the data stream is patterned to learn from the neural network model, and the difference between the output value and probability vector of the current data and the historical data of these learned neural network models is compared to detect the concept drift. The proposed method confirmed that only CNN output values could be used to reduce detection errors compared to how concept drift were detected.

Optimal Zero Vector Selecting Method to Reduce Switching Loss on Model Predictive Control of VSI (전압원 인버터의 모델 예측 제어에서 스위칭 손실을 줄이기 위한 최적의 제로 벡터 선택 방법)

  • Park, Jun-Cheol;Park, Chan-Bae;Baek, Jei-Hoon;Kwak, Sang-Shin
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.3
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    • pp.273-279
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    • 2015
  • A zero vector selection method to reduce switching losses for model predictive control (MPC) of voltage source inverter is proposed. A conventional MPC of voltage source inverter has not been proposed, and a method to select the redundancy of the zero vector is required for this study. In this paper, the redundancy of the zero vectors is selected with generating a zero sequence voltage to reduce switching losses. The zero vector of 2-level inverter is determined by determining sign of the zero sequence voltage. In the proposed method, the quality of the current is retained and switching loss can be reduced compared with the conventional method. This result was verified by P-sim simulation and experiments.