• Title, Summary, Keyword: control selection

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A New Field/Frame Mode Selection and Buffer Control Strategy for Interlaced Digtal HDTV Image Coding (비월 주사 방식의 디지탈 HDTV 영상 부호화를 위한 새로운 필드/프레임 모드 선택 및 버퍼 제어 기법)

  • 김중곤;송규익;김덕규;김건일
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.8
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    • pp.109-118
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    • 1994
  • We proposed new field/frame mode selection quantization and buffer control strategy for interlaced digital HDTV image coding system. The field/frame mode selection is performed based on the mean square error and number of generated bits for each superblock. The quantization factor for each superblock is determined by the characteristics of human visual system and buffer status. The statistical characteristics of the number of generated bits for basis block and the prediction of buffer status are used for buffer control. Simulation results show that the proposed field/frame mode selection and rate buffer control. Simulation results show that the proposed field/frame mode selection and rate buffer control strategy have good subjective image quality and have stable buffer status.

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SELECTION PROCEDURES TO SELECT POPULATIONS BETTER THAN A CONTROL

  • Kumar, Narinder;Khamnel, H.J.
    • Journal of the Korean Statistical Society
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    • v.32 no.2
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    • pp.151-162
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    • 2003
  • In this paper, we propose two selection procedures for selecting populations better than a control population. The bestness is defined in terms of location parameter. One of the procedures is based on two-sample linear rank statistics whereas the other one is based on a comparatively simple statistic, and is useful when testing time is expensive so that an early termination of an experiment is desirable. The proposed selection procedures are seen to be strongly monotone. Performance of the proposed procedures is assessed through simulation study.

Trust-based Relay Selection in Relay-based Networks

  • Wu, Di;Zhu, Gang;Zhu, Li;Ai, Bo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.10
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    • pp.2587-2600
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    • 2012
  • It has been demonstrated that choosing an appropriate relay node can improve the transmission rate for the system. However, such system improvement brought by the relay selection may be degraded with the presence of the malicious relay nodes, which are selected but refuse to cooperate for transmissions deliberately. In this paper, we formulate the relay selection issue as a restless bandit problem with the objective to maximize the average rate, while considering the credibility of each relay node, which may be different at each time instant. Then the optimization problem is solved by using the priority-index heuristic method effectively. Furthermore, a low complexity algorithm is offered in order to facilitate the practical implementations. Simulation results are conducted to demonstrate the effectiveness of the proposed trust-based relay selection scheme.

A Fully Differential RC Calibrator for Accurate Cut-off Frequency of a Programmable Channel Selection Filter

  • Nam, Ilku;Choi, Chihoon;Lee, Ockgoo;Moon, Hyunwon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.5
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    • pp.682-686
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    • 2016
  • A fully differential RC calibrator for accurate cut-off frequency of a programmable channel selection filter is proposed. The proposed RC calibrator consists of an RC timer, clock generator, synchronous counter, digital comparator, and control block. To verify the proposed RC calibrator, a six-order Chebyshev programmable low-pass filter with adjustable 3 dB cut-off frequency, which is controlled by the proposed RC calibrator, was implemented in a $0.18-{\mu}m$ CMOS technology. The channel selection filter with the proposed RC calibrator draws 1.8 mA from a 1.8 V supply voltage and the measured 3 dB cut-off frequencies of the channel selection LPF is controlled accurately by the RC calibrator.

Antenna Selection and Power Control Method for Uniform Circular Array Antennas Beamforming (원형 배열 안테나 빔 형성을 위한 안테나 선택 및 제어 방법)

  • Park, Seongho;Park, Chul;Kim, Hanna;Chung, Jaehak
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.1
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    • pp.68-76
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    • 2015
  • This paper proposes the antenna selection scheme and power control algorithms of multiple nodes beamforming when the vehicles equipped with circular array antennas is moving and construct mobile mesh networks. The proposed antenna selection scheme chooses beamforming antenna elements considering antenna radiation gain and allows duplicated antenna selection for multiple adjacent nodes. The proposed power control algorithms maximize SIR for the duplicated antenna selection. The simulation demonstrates that the proposed antenna selection and power control achieve 2.5dB higher SIR gain than that of conventional methods when two nodes are apart from $15^{\circ}$.

Modeling of Positive Selection for the Development of a Computer Immune System and a Self-Recognition Algorithm

  • Sim, Kwee-Bo;Lee, Dong-Wook
    • International Journal of Control, Automation, and Systems
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    • v.1 no.4
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    • pp.453-458
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    • 2003
  • The anomaly-detection algorithm based on negative selection of T cells is representative model among self-recognition methods and it has been applied to computer immune systems in recent years. In immune systems, T cells are produced through both positive and negative selection. Positive selection is the process used to determine a MHC receptor that recognizes self-molecules. Negative selection is the process used to determine an antigen receptor that recognizes antigen, or the nonself cell. In this paper, we propose a novel self-recognition algorithm based on the positive selection of T cells. We indicate the effectiveness of the proposed algorithm by change-detection simulation of some infected data obtained from cell changes and string changes in the self-file. We also compare the self-recognition algorithm based on positive selection with the anomaly-detection algorithm.

Voltage Vector Selection Area of the Direct Torque Control for Permanent Magnet Synchronous Motor

  • Li, Yaohua;Ma, Jian;Yu, Qiang;Liu, Jingyu
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.2
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    • pp.23-29
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    • 2012
  • The control of stator flux, torque angle, excitation torque, reluctance torque and total torque of the direct torque control (DTC) for a permanent magnet synchronous motor (PMSM) are studied in this paper. Simplified expressions to represent the changes of these variables due to the application of a voltage vector are given. Finally, a voltage vector selection area and the implementation of a voltage vector selection strategy are proposed.

Optimal Voltage Vector Selection Method for Torque Ripple Reduction in the Direct Torque Control of Five-phase Induction Motors

  • Kang, Seong-Yun;Shin, Hye Ung;Park, Sung-Min;Lee, Kyo-Beum
    • Journal of Power Electronics
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    • v.17 no.5
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    • pp.1203-1210
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    • 2017
  • This paper presents an improved switching selection method for the direct torque control (DTC) of five-phase induction motors (IMs). The proposed method is conducted using optimal switching selection. A five-phase inverter has 32 voltage vectors which are divided into 30 nonzero voltage vectors and two zero voltage vectors. The magnitudes of the voltage vectors consist of large, medium, and small voltage vectors. In addition, these vectors are related to the torque response and torque ripple. When a large voltage vector is selected in a drive system, the torque response time decreases with an increased torque ripple. On the other hand, when a small voltage vector is selected, the torque response time and torque ripple increase. As a result, this paper proposes an optimal voltage vector selection method for improved DTC of a five-phase induction machine depending on the situation. Simulation and experimental results verify the effectiveness of the proposed control algorithm.

A Study on Selection Criterions for Selection Diversity in WAVE Systems (WAVE 시스템에서 선택 다이버시티를 위한 선택 기준에 대한 연구)

  • Hong, Dae-Ki
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.2
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    • pp.9-16
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    • 2015
  • In this paper, selection criterions on selection diversity are researched. The diversity is applied to the multiple antenna system based on wireless access in vehicular environment (WAVE) standard for rapid varying channel. Least squares (LS) based decision feedback equalizer (DFE) are used for channel equalization. Received signal is regenerated by means of the decision feedback path. In the selection diversity, the regenerated signal as well as the received signal is selected according to selection criterion. The decision feedback algorithm can follow the fast speed of WAVE fading channel. To control the tracking speed of the time-varying channel, simple low pass filter is used. Finally, the estimated channel value recovers the distorted payloads. Signal power before automatic gain control (AGC) in analog stage can be used as a selection criterion. In the digital stage, signal power after AGC, noise power after AGC, signal to noise ratio after AGC and cross-correlation method can be used as selection criterions. According to the simulation results, the performance of the selection diversity is improved in comparison with that of the combining diversity for the WAVE fading channel.

Optimal actuator selection for output variance constrained control

  • 김재훈
    • 제어로봇시스템학회:학술대회논문집
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    • pp.565-569
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    • 1993
  • In this paper, a specified number of actuators are selected from a given set of admissible actuators. The selected set of actuators is likely to use minimum control energy while required output variance constraints are guaranteed to be satisfied. The actuator selection procedure is an iterative algorithm composed of two parts; an output variance constrained control and an input variance constrained control algorithm. The idea behind this algorithm is that the solution to the first control problem provides the necessary weighting matrix in the objective function of the second optimization problem, and the sensitivity information from the second problem is utilized to delete one actuator. For variance constrained control problems, by considering a dual version of each control problem an efficient algorithm is provided, whose convergence properties turn out to be better than an existing algorithm. Numerical examples with a simple beam are given for both the input/output variance constrained control problem and the actuator selection problem.

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