• Title/Summary/Keyword: Fuzzy control

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A Study on Number Setting of Competitive Layer using fuzzy Control Method for Enhanced Counterpropagation Algorithm (개선된 Counterpropagation 알고리즘에서 퍼지 제어 기법을 이용한 경쟁층의 수 설정에 관한 연구)

  • Kim, Tae-Hyung;Cho, Jae-Hyun;Woo, Young-Woon;Kim, Kwang-Baek
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.05a
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    • pp.359-365
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    • 2008
  • CP(Counterpropagation)알고리즘은 서로 다른 두 개의 신경망이 하나로 결합 된 혼합형 모델로서, 다른 신경망 모델에 비해 비교적 단순하고 빠른 학습 속도를 보인다. 그러나 CP 알고리즘은 다양한 패턴이 입력되면 충분한 경쟁층의 수가 설정되지 않아 학습이 불안정하고, 출력층에서 연결강도를 조정할 때 일반적인 학습률 조정방법으로 불안정한 학습 결과를 보인다. 이러한 문제점을 해결하기 위해 다수의 경쟁층을 설정하여 경쟁층에서 패턴 분류의 정확성을 높이고, 입력 벡터와 승자 뉴런의 대표 벡터간의 차이와 승자 빈도수를 반영하여 학습률을 동적으로 조정하여 경쟁층에서의 학습이 안정적으로 진행되도록 하고, 출력층에서 연결강도를 조정할 때 모멘텀(momentum)학습법을 적용한 개선된 CP 알고리즘이 제안되었다. 본 논문에서는 개선된 CP 알고리즘에서 경쟁층의 수를 효율적으로 설정하기 위해 퍼지 제어 기법을 이용하여 경쟁층의 수를 결정하는 방법을 제안한다. 제안된 방법은 CP 알고리즘에 입력되는 패턴의 정보를 이용하여 퍼지 소속 함수를 설계하고 입력에 대한 소속도를 계산한 후, 퍼지 제어 규칙을 적용하고, Mamdani의 Min_Max 추론 방법으로 추론한다. 퍼지 추론을 통해 최종적으로 얻어진 값을 무게 중심법으로 비퍼지화 하여 최종적으로 개선된 CP 알고리즘의 경쟁층의 수를 결정하는데 적용한다. 제안된 방법의 학습 및 인식 성능을 평가하기 위해, 숫자, 영어 등과 같이 다양한 패턴을 실험에 적용한 결과, 제안된 방법이 경쟁층의 수를 결정하는데 효과적임을 확인할 수 있었다.

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New Dynamic WRR Algorithm for QoS Guarantee in DiffServ Networks (DiffServ 망에서 QoS를 보장하기 위한 새로운 동적 가중치 할당 알고리즘 개발)

  • Chung Dong-Su;Kim Byun-Gon;Park Kwang-Chae;Cho Hae-Seong
    • The Journal of the Korea Contents Association
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    • v.6 no.7
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    • pp.58-68
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    • 2006
  • There are two traditional scheduling methods known as PQ and WRR in the DiffServ network, however, these two scheduling methods have some drawbacks. In this paper, we propose an algorithm that can be adopted in WRR scheduler with making up for weak points of PQ and WRR. The proposed algorithm produces the control discipline by the fuzzy theory to dynamically assign the weight of WRR scheduler with checking the Queue status of each class. To evaluate the performance of the proposed algorithm, We accomplished a computer simulation using NS-2. From simulation results, the proposed algorithm improves the packet loss rate of the EF class traffic to 6.5% by comparison with WRR scheduling method and that of the AF4 class traffic to 45% by comparison with PQ scheduling method.

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Pedestrian crosswalk fused sensor data and time information in the Safety Assistive systems research (센서 데이터 및 시간 정보를 융합한 횡단보도 내 보행자 안전 보행 보조 시스템 연구)

  • Lim, Shin-Teak;Park, Jong-Ho;Chong, Kil-To
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.12
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    • pp.6040-6045
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    • 2012
  • In this study, by utilizing the information fusion of multi sensor data and time within the crosswalk safety Assistive gait secondary to the safety of pedestrians on the system design and system performance verification through support to. Environmental awareness, and time information in addition to leveraging the default behavior for pedestrian safety design of the secondary system performed a study on the scenario and the behavior of a system for fuzzy control was performed for each sensor data processing, median filtering, including filters processing leveraging, and was attached by the time we complete the final algorithm, the system behavior. In addition, taking advantage of the sensor measurements, so basically uncertainties and sensor results, and you want to give at least the reliability of the data fusion experiment equipment using this simple verification.

A dynamic WRR Algorithm for QoS Guarantee in DiffServ Networks (DiffServ 망에서 QoS를 보장하기 위한 동적 가중치 할당 알고리즘)

  • Chung, Dong-Su;Kim, Byun-Gon;Cho, Hae-Seong;Chung, Kyung-Taek;Kim, Nam-Hee;Lee, Jong-In
    • Proceedings of the Korea Contents Association Conference
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    • 2006.05a
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    • pp.128-131
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    • 2006
  • There are two traditional scheduling methods known as PQ and WRR in the DiffServ network, however, these two scheduling methods have some drawbacks. In this paper, we propose an algorithm that can be adopted in WRR scheduler with making up for weak points of PQ and WRR. The proposed algorithm produces the control discipline by the fuzzy theory to dynamically assigns the weight of WRR scheduler with checking the Queue status of each class. To evaluate the performance of the proposed algorithm, We accomplished a computer simulation using NS-2. In result, the proposed algorithm enhances the packet discard rate at the EF class than WRR scheduling method and the AF4 class than PQ scheduling method.

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A Study on the System Dynamics Analysis for Human Factors in Ship′s Collision Accidents (시스템 다이내믹스에 의한 선박충돌사고의 인적요인 분석에 관한 연구)

  • Keum, Jong-Soo;Yang, Weon-Jae;Jang, Woon-Jae
    • Journal of Navigation and Port Research
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    • v.27 no.5
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    • pp.493-498
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    • 2003
  • Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, An analysis on the ship's collision muses is very important to prepare countermeasures which will ensure the safe navigation. And the analysis confirmed that ship's collision is occurred most frequently and the muse is closely related with human factor. The main purpose of this study is to build a model of human factors in ship's collision muse using SD(System Dynamics} approach and to measure a effect which is risk control countermeasures of ship's collision. To achieve this aim, the structure analysis on the muses of ship's collision using FSM are performed, and the structure was changed by quantitative, qualitative factors and their feedback loops in casual map. This model was performed over 20 years(1993-2012) in a standard simulation model and 8 policy simulation models.

A study on the Urban Growth Model of Gimhae City Using Cellular Automata (셀룰라 오토마타를 이용한 김해시의 도시성장모형에 관한 연구 - 1987~2001년을 중심으로 -)

  • Lee, Sung Ho;Yun, Jeong Mi;Seo, Kyung Chon;Nam, Kwang Woo;Park, Sang Chul
    • Journal of the Korean Association of Geographic Information Studies
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    • v.7 no.3
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    • pp.118-125
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    • 2004
  • The purpose of this study is to decide an appropriate neighborhood and a transition rule of cellular automata by analyzing the past growth process of urban areas in Gimhae. With cellular automata which can manage the change based on the dynamic model and time, this study analyzes the urban growth of Gimhae from 1987 to 2001. Also, through the simulation of different types for neighborhood and transition rules, we can find the appropriate neighborhood and the transition rule for Gimhae. In conclusion, the forecast of physical urban growth pattern is more accurate under conditions when the number of matrixes for the neighborhood is small, the shape of the neighborhood is rectangular, "${\alpha}$" value, which control the pace of urban growth, is low and the transition possibility ($P_{ij}$) is high.

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Face Detection for Automatic Avatar Creation by using Deformable Template and GA (Deformable Template과 GA를 이용한 얼굴 인식 및 아바타 자동 생성)

  • Park Tae-Young;Kwon Min-Su;Kang Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.1
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    • pp.110-115
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    • 2005
  • This paper proposes the method to detect contours of a face, eyes and a mouth in a color image for making an avatar automatically. First, we use the HSI color model to exclude the effect of various light condition, and we find skin regions in an input image by using the skin color is defined on HS-plane. And then, we use deformable templates and Genetic Algorithm(GA) to detect contours of a face, eyes and a mouth. Deformable templates consist of B-spline curves and control point vectors. Those can represent various shape of a face, eyes and a mouth. And GA is very useful search procedure based on the mechanics of natural selection and natural genetics. Second, an avatar is created automatically by using contours and Fuzzy C-means clustering(FCM). FCM is used to reduce the number of face color As a result, we could create avatars like handmade caricatures which can represent the user's identity, differing from ones generated by the existing methods.

Segment-based Buffer Management for Multi-level Streaming Service in the Proxy System (프록시 시스템에서 multi-level 스트리밍 서비스를 위한 세그먼트 기반의 버퍼관리)

  • Lee, Chong-Deuk
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.11
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    • pp.135-142
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    • 2010
  • QoS in the proxy system are under heavy influence from interferences such as congestion, latency, and retransmission. Also, multi-level streaming services affects from temporal synchronization, which lead to degrade the service quality. This paper proposes a new segment-based buffer management mechanism which reduces performance degradation of streaming services and enhances throughput of streaming due to drawbacks of the proxy system. The proposed paper optimizes streaming services by: 1) Use of segment-based buffer management mechanism, 2) Minimization of overhead due to congestion and interference, and 3) Minimization of retransmission due to disconnection and delay. This paper utilizes fuzzy value $\mu$ and cost weight $\omega$ to process the result. The simulation result shows that the proposed mechanism has better performance in buffer cache control rate, average packet loss rate, and delay saving rate with stream relevance metric than the other existing methods of fixed segmentation method, pyramid segmentation method, and skyscraper segmentation method.

Control Performance Evaluation of Smart Mid-story Isolation System with RNN Model (RNN 모델을 이용한 스마트 중간층 면진시스템의 제어성능 평가)

  • Kim, Hyun-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.774-779
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    • 2020
  • The seismic response reduction capacity of a smart mid-story isolation system was investigated using the RNN model in this study. For this purpose, an RNN model was developed to make a dynamic response prediction of building structures subjected to seismic loads. An existing tall building with a mid-story isolation system was selected as an example structure for realistic research. A smart mid-story isolation system was comprised of an MR damper instead of existing lead dampers. The RNN model predicted the seismic responses accurately compared to those of the FEM model. The simulation time of the RNN model can be reduced significantly compared to the FEM model. After the numerical simulations, the smart mid-story isolation system could effectively reduce the seismic responses of the existing building compared to the conventional mid-story isolation system.