• Title/Summary/Keyword: 슬라이딩 알고리즘

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Multipath Search Algorithm based on Sliding Window (슬라이딩 윈도우를 이용한 다중 경로 탐색 알고리즘)

  • 유현규;권종현;전형구;홍대식;강창언
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.69-72
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    • 2000
  • In CDMA systems, the performance of the typical multipath searcher degrades much according as the signal to noise ratio becomes low. In this paper, multipath searcher algorithm is proposed based on sliding window to overcome this drawback. In searcher systems, correlation values between incoming and local PN sequences are used to acquire multipath components. Therefore more accurate distributions of correlation values obtained through this proposed algorithm enables to get higher detection probability. In computer simulations, it is verified that proposed algorithm has better performances in Rayleigh fading channel and Gaussian channel.

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fuzzy sliding controller design using genetic algorithm (유전 알고리즘을 이용한 퍼지 슬라이딩 제어기 설계)

  • 한종길;유병국;함운철
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.964-967
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    • 1996
  • In this paper, we present a fuzzy-sliding controller design using genetic algorithm. We can suppress chattering and enhance the robustness of controlled system by using this controller and do that genetic algorithm can easily find out a nearly optimal fuzzy rule performance of this controller is tested by simulation of car system with two pole.

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The Control of Z-Source Inverter for using DC Renewable Energy (직류 대체에너지 활용을 위한 Z-원 인버터 제어)

  • Park, Young-San;Bae, Cherl-O;Nam, Taek-Kun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.13 no.2 s.29
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    • pp.169-172
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    • 2007
  • This paper presents circuit models and control algorithms of distributed generation system(DGS) which consists of Z-type converter and PWM inverter. Z-type converter which employs both the L and C passive components and shoot-through zero vectors instead qf the conventional DC/DC converter in order to step up DC-link voltage. Discrete time sliding mode control with the asymptotic observer is used for current control. This system am be used for power conversion of DC renewable energy.

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Phase Portrait Analysis-Based Safety Control for Excavator Using Adaptive Sliding Mode Control Algorithm (적응형 슬라이딩 모드 제어를 이용한 위상 궤적 해석 기반 굴삭기의 안전제어 알고리즘 개발)

  • Oh, Kwang Seok;Seo, Ja Ho;Lee, Geun Ho
    • Journal of Drive and Control
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    • v.15 no.3
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    • pp.8-13
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    • 2018
  • This paper presents a phase portrait analysis-based safety control algorithm for excavators, using adaptive sliding mode control. Since working postures and material types cause the excavator's rotational inertia to vary, the rotational inertia was estimated, and this estimation was used to design an adaptive sliding mode controller for collision avoidance of the excavator. In order to estimate the rotational inertia, the recursive least-squares estimation with multiple forgetting was applied with the information of the swing velocity of the excavator. For realistic evaluation, an actual working scenario-based performance evaluation was conducted. Based on the estimated rotational inertia and an analysis of estimation errors, sliding mode control inputs were computed. The actual working scenario-based performance evaluation of the designed safety algorithm was conducted, and the results showed that the developed safety control algorithm can efficiently avoid a collision with an object in consideration of rotational inertia variations.

Tracking Control of Variable Structure System with a New Variable Boundary Layer (새로운 가변 경계층을 갖는 가변 구조 제어 시스템의 추적 제어)

  • Lee, Hui-Jin;Kim, Eun-Tae;Kim, Dong-Yeon
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.37 no.3
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    • pp.19-32
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    • 2000
  • This paper suggests the variable structure controller with a new variable boundary layer for the accurate tracking control of the variable structure systems. Up to now, variable structure controller (VSC) applying the variable boundary layer did not remove chattering from an arbitrary initial state of the system trajectory because VSC has the limited initial state according to the fixed sliding surface. But, by using the linear time-varying sliding surfaces, the scheme has the robustness against chattering from all states. The suggested method can be applied to the second-order nonlinear systems with parameter uncertainty and extraneous disturbances, and has better tracking performance than the conventional method. To demonstrate the advantages of the proposed algorithm, it is applied to a two-link manipulator.

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Stream Data Processing based on Sliding Window at u-Health System (u-Health 시스템에서 슬라이딩 윈도우 기반 스트림 데이터 처리)

  • Kim, Tae-Yeun;Song, Byoung-Ho;Bae, Sang-Hyun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.4 no.2
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    • pp.103-110
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    • 2011
  • It is necessary to accurate and efficient management for measured digital data from sensors in u-health system. It is not efficient that sensor network process input stream data of mass storage stored in database the same time. We propose to improve the processing performance of multidimensional stream data continuous incoming from multiple sensor. We propose process query based on sliding window for efficient input stream and found multiple query plan to Mjoin method and we reduce stored data using backpropagation algorithm. As a result, we obtained to efficient result about 18.3% reduction rate of database using 14,324 data sets.

A Study on Startup-Characteristic of Sensorless Controlled IPMSM Employing Sliding Mode Observer (슬라이딩 모드 관측기를 이용한 IPMSM의 센서리스 제어의 기동특성에 관한 연구)

  • Kim, Sang-Hun;Kwon, Soon-Jae;Kim, Marn-Go;Jung, Young-Seok
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.1
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    • pp.38-43
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    • 2011
  • This paper presents the improvement of start-up characteristic of sensorless controlled IPMSM(Interior Permanent Magnet Synchronous Motor) with SMO(Sliding Mode Observer). It is difficult to utilize the rotor position information at starting point for the back EMF estimation based sensorless control. For this reason, open loop control is normally used during start-up period. However, changing from open loop to closed loop control might bring a problem on the transient characteristics for difference load conditions. To solve this problem, we add another rotor angle controller. Simulation results and experimental results are presented to verify proposed method.

Robust control of a heave compensation system for offshore cranes considering the time-delay (시간 지연을 고려한 해상 크레인의 상하 동요 보상 시스템의 강인 제어)

  • Seong, Hyung-Seok;Choi, Hyeong-Sik
    • Journal of Advanced Marine Engineering and Technology
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    • v.41 no.1
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    • pp.105-110
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    • 2017
  • This paper introduces a heave compensation system for offshore crane when it subjected to unexpected disturbances such as ocean waves, tidal currents or winds and their external force. The dynamic model consists of a crane which is considered to behave in the same manner as a rigid body, a hydraulic driven winch, an elastic rope and a payload. To keep the payload from moving upwards and downwards, PD(Proportional-Derivative) control was applied by using linearization. In order to achieve a better performance, the sliding mode control and the nonlinear generalized predictive control algorithm was applied according to the time-delay. As a result, the oscillating amplitude of the payload was reduced by the control algorithm. Considering the time-delay involved in the system to be one second, nonlinear generalized predictive controller with a robust controller was a suitable control algorithm for this heave compensation system because it made the position of te payload reach the desired position with the minimum error. This paper presented a control algorithm using the robust control and its simulation results.

(Turbo Decoder Design with Sliding Window Log Map for 3G W-CDMA) (3세대 이동통신에 적합한 슬라이딩 윈도우 로그 맵 터보 디코더 설계)

  • Park, Tae-Gen;Kim, Ki-Hwan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.9 s.339
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    • pp.73-80
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    • 2005
  • The Turbo decoders based on Log-MAP decoding algorithm inherently requires large amount of memory and intensive complexity of hardware due to iterative decoding, despite of excellent decoding efficiency. To decrease the large amount of memory and reduce hardware complexity, the result of previous research. And this paper design the Turbo decoder applicable to the 3G W-CDMA systems. Through the result of previous research, we decided 5-bits for the received data 6-bits for a priori information, and 7-bits for the quantization state metrics. The error correction term for $MAX^{*}$ operation which is the main function of Log-MAP decoding algorithm is implemented with very small hardware overhead. The proposed Turbo decoder is synthesized in $0.35\mu$m Hynix CMOS technology. The synthesized result for the Turbo decoder shows that it supports a maximum 9Mbps data rate, and a BER of $10^{-6}$ is achieved(Eb/No=1.0dB, 5 iterations, and the interleaver size $\geq$ 2000).

A Design of Collision Avoidance System of an Underwater Vehicle (수중운동체의 충돌회피시스템에 대한 연구)

  • Nam-Sun Son;Key-Pyo Rhee;Sang-Mu Lee;Dong-Jin Yeo
    • Journal of the Society of Naval Architects of Korea
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    • v.38 no.4
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    • pp.23-29
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    • 2001
  • An Obstacle Avoidance System(OAS) of Underwater Vehicle(UV) in diving and steering plane is investigated. The concept of Imaginary Reference Line(IRL), which acts as the seabed in the diving plane, is introduced to apply the diving plane avoidance algorithm to the steering plane algorithm. Furthermore, the distance to the obstacle and the slope information of the obstacle are used for more efficient and safer avoidance. As for the control algorithm, the sliding mode controller is adopted to consider the nonlinearity of the equations of motion and to get the robustness of the designed system. To verify the obstacle avoidance ability of the designed system, numerical simulations are carried out on the cases of some presumed three-dimensional obstacles. The effects of the sonar and the clearance factor used in avoidance algorithm are also investigated. Through these, it is found that the designed avoidance system can successfully cope with various obstacles and the detection range of sonar is proven to bea significant parameter to the performance of the avoidance.

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