• Title/Summary/Keyword: hybrid systems

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Fuzzy Relation-Based Fuzzy Neural-Networks Using a Hybrid Identification Algorithm

  • Park, Ho-Seung;Oh, Sung-Kwun
    • International Journal of Control, Automation, and Systems
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    • v.1 no.3
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    • pp.289-300
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    • 2003
  • In this paper, we introduce an identification method in Fuzzy Relation-based Fuzzy Neural Networks (FRFNN) through a hybrid identification algorithm. The proposed FRFNN modeling implement system structure and parameter identification in the efficient form of "If...., then... " statements, and exploit the theory of system optimization and fuzzy rules. The FRFNN modeling and identification environment realizes parameter identification through a synergistic usage of genetic optimization and complex search method. The hybrid identification algorithm is carried out by combining both genetic optimization and the improved complex method in order to guarantee both global optimization and local convergence. An aggregate objective function with a weighting factor is introduced to achieve a sound balance between approximation and generalization of the model. The proposed model is experimented with using two nonlinear data. The obtained experimental results reveal that the proposed networks exhibit high accuracy and generalization capabilities in comparison to other models.er models.

Performance Analysis of Wired/Wireless Hybrid Network based on Common Industrial Protocol (Common Industrial Protocol 기반의 유무선 하이브리드 네트워크에 관한 성능 분석)

  • Jung, Ji-Won;Lee, Seung-Ki;Kim, Dong-Sung
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.11
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    • pp.1119-1127
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    • 2007
  • This paper is concerned with a performance analysis using a wired/wireless hybrid network based on Common Industrial Protocol(CIP). For the performance analysis, the data transmission time, average end-to-end delay and throughput between DeviceNet and the wireless devices are investigated. The experimental results show the performance in terms of the polling/COS service time of CIP based hybrid network.

Depth Image Based Feature Detection Method Using Hybrid Filter (융합형 필터를 이용한 깊이 영상 기반 특징점 검출 기법)

  • Jeon, Yong-Tae;Lee, Hyun;Choi, Jae-Sung
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.6
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    • pp.395-403
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    • 2017
  • Image processing for object detection and identification has been studied for supply chain management application with various approaches. Among them, feature pointed detection algorithm is used to track an object or to recognize a position in automated supply chain systems and a depth image based feature point detection is recently highlighted in the application. The result of feature point detection is easily influenced by image noise. Also, the depth image has noise itself and it also affects to the accuracy of the detection results. In order to solve these problems, we propose a novel hybrid filtering mechanism for depth image based feature point detection, it shows better performance compared with conventional hybrid filtering mechanism.

Parameter Identification of an Electro-Hydraulic Servo System Using a Modified Hybrid Neural-Genetic Algorithm (전기.유압 서보시스템의 수정된 신경망-유전자 알고리즘에 의한 파라미터 식별)

  • 곽동훈;이춘태;정봉호;이진걸
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.6
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    • pp.442-447
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    • 2003
  • This paper demonstrates that a modified hybrid neural-genetic multimodel parameter estimation algorithm can be applied to structured system identification of an electro-hydraulic servo system. This algorithm is consists of a recurrent incremental credit assignment(ICRA) neural network and a genetic algorithm. The ICRA neural network evaluates each member of a generation of model and genetic algorithm produces new generation of model. The modified hybrid neural-genetic multimodel parameter estimation algorithm is applied to an electro-hydraulic servo system the task to find the parameter values such as mass, damping coefficient, bulk modulus, spring coefficient and disturbance, which minimizes the total square error.

A Hybrid Method for classifying User's Asking Points (하이브리드 방법의 사용자 질의 의도 분류)

  • Harksoo Kim;An, Young Hun;Jungyun Seo
    • Journal of KIISE:Software and Applications
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    • v.30 no.1_2
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    • pp.51-57
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    • 2003
  • For QA systems to return correct answer phrases, it is very important that they correctly and stably analyze users' intention. To satisfy this need, we propose a question type classifier (i.e. asking point identifier) for practical QA systems. The classifier uses a hybrid method that combines a statistical method with a rule-based method according to some heuristic rules. Owing to the hybrid method, the classifier can reduce the time to manually construct rules, yield high precision rate and guarantee robustness. In the experiment, we accomplished 80% accuracy of the question type classification.

Study on Hybrid PWM Method under Low Switching Frequency

  • Kekang, Wei;Zheng, Trillion Q.;Wang, Ran;Wang, Chenchen
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.2
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    • pp.64-69
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    • 2012
  • This paper presents a hybrid pulse width modulation (PWM) method under low switching frequency conditions based on space vector PWM (SVPWM) and selective harmonic eliminated PWM (SHEPWM), which use asynchronous carrier modulation SVPWM at low frequency, and SHEPWM at high frequency, a square wave after rated conditions. A transitive strategy is proposed to realize a smooth transition of individual modes including SVPWM, SHEPWM and square waves. Experimental results confirm this hybrid modulation method and their transition are reasonable and proper.

A Hybrid of Evolutionary Search and Local Heuristic Search for Combinatorial Optimization Problems

  • Park, Lae-Jeong;Park, Cheol-Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.1 no.1
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    • pp.6-12
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    • 2001
  • Evolutionary algorithms(EAs) have been successfully applied to many combinatorial optimization problems of various engineering fields. Recently, some comparative studies of EAs with other stochastic search algorithms have, however, shown that they are similar to, or even are not comparable to other heuristic search. In this paper, a new hybrid evolutionary algorithm utilizing a new local heuristic search, for combinatorial optimization problems, is presented. The new intelligent local heuristic search is described, and the behavior of the hybrid search algorithm is investigated on two well-known problems: traveling salesman problems (TSPs), and quadratic assignment problems(QAPs). The results indicate that the proposed hybrid is able to produce solutions of high quality compared with some of evolutionary and simulated annealing.

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Attitiude Control of Helicopter Simulator System using A Hybrid GA-PID WAVENET Controller (Hybrid GA-PID WAVENET 제어기를 이용한 모형 헬리콥터 시스템의 자세 제어)

  • 박두환;성상규;이오걸;이준탁
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2004.04a
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    • pp.168-171
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    • 2004
  • 본 논문에서는 대표적인 비선형 동특성을 가지는 실제 헬리콥터의 회전 및 자세 운동을 근사화한 모형 헬리콥터의 시스템을 소개하고 이 시스템의 정지 자세 제어를 위하여 WAVENET 제어기와 PID 제어기를 설계하였으며, WAVENET의 신경망 연결 가중치(weight) 및 웨이브렛의 신축 및 이동변수와 PID 제어기의 최적 이득 계수를 GA를 사용하여 조정되도록 하였다. 그리고 과도 응답 특성이 우수한 WAVENET 제어기와 정상 상태 특성이 우수한 GA-PID 제어기를 Hybrid 형태로 구성한 Hybrid GA-PID WAVENET 제어기를 비선형 시스템인 모형 헬리콥터 시스템에 적용하여 제안한 제어기 설계 알고리즘의 유효성과 우수성을 입증하고자 한다.

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Hybrid combiner design for downlink massive MIMO systems

  • Seo, Bangwon
    • ETRI Journal
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    • v.42 no.3
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    • pp.333-340
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    • 2020
  • We consider a hybrid combiner design for downlink massive multiple-input multiple-output systems when there is residual inter-user interference and each user is equipped with a limited number of radio frequency (RF) chains (less than the number of receive antennas). We propose a hybrid combiner that minimizes the mean-squared error (MSE) between the information symbols and the ones estimated with a constant amplitude constraint on the RF combiner. In the proposed scheme, an iterative alternating optimization method is utilized. At each iteration, one of the analog RF and digital baseband combining matrices is updated to minimize the MSE by fixing the other matrix without considering the constant amplitude constraint. Then, the other matrix is updated by changing the roles of the two matrices. Each element in the RF combining matrix is obtained from the phase component of the solution matrix of the optimization problem for the RF combining matrix. Simulation results show that the proposed scheme performs better than conventional matrix-decomposition schemes.

Performance Comparison of a Fabric Filter System with Centrifugal Force and a Conventional Fabric Filter System (원심력이 적용된 여과포집진장치와 기존 집진장치의 성능비교)

  • Kim Sang-Do;Park Young-Ok;Kang Yong
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.6
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    • pp.739-748
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    • 2004
  • A hybrid dust-collector combining a fabric filter with centrifugal force was developed to enhance the performance of the conventional fabric filter systems and its performances were evaluated to compare to that of the existing dust collector. The pressure drop rapidly increased with increasing the elapsed time and the face velocity in two filtration systems. But the increasing ratio of a hybrid dust-collector compare to the existing dust collector was lower. This results were confirmed from the performance such as cleaning interval, residual pressure drop and dust loading rate. The overall collection efficiency of the hybrid dust-collector was more than 99.6% and this showed a improvement of 0.6~2% than that of the existing dust collector. Especially, the fractional collection efficiency at the particle size of around 1${\mu}{\textrm}{m}$ is about 4% higher than that of the existing dust collector.