• Title/Summary/Keyword: Scaling Function

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Analysis and Auto-tuning of Scale Factors of Fuzzy Logic Controller

  • Lee, Chul-Heui;Seo, Seon Hak
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.51-56
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    • 1998
  • In this paper, we analyze the effects of scaling factors on the performance of a fuzzy logic controller(FLC). The quantitative relation between input and output variables of FLC is obtained by using a qualsi-linear fuzzy model, and an approximate transfer function of FLC is dervied from the comparison of it with the conventional PID controller. Then we analyze in detail the effects of scaling factor using this approximate transfer function and root locus method. Also we suggest an on-line tuning method for scaling factors which employs an sample performance function and a variable reference for tuning index.

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Scale Invariant Single Face Tracking Using Particle Filtering With Skin Color

  • Adhitama, Perdana;Kim, Soo Hyung;Na, In Seop
    • International Journal of Contents
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    • v.9 no.3
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    • pp.9-14
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    • 2013
  • In this paper, we will examine single face tracking algorithms with scaling function in a mobile device. Face detection and tracking either in PC or mobile device with scaling function is an unsolved problem. Standard single face tracking method with particle filter has a problem in tracking the objects where the object can move closer or farther from the camera. Therefore, we create an algorithm which can work in a mobile device and perform a scaling function. The key idea of our proposed method is to extract the average of skin color in face detection, then we compare the skin color distribution between the detected face and the tracking face. This method works well if the face position is located in front of the camera. However, this method will not work if the camera moves closer from the initial point of detection. Apart from our weakness of algorithm, we can improve the accuracy of tracking.

Design of the Adaptive Fuzzy Control Scheme and its Application on the Steering Control of the UCT (무인 컨테이너 운송 조향 제어의 적응 퍼지 제어와 응용)

  • 이규준;이영진;윤영진;이원구;김종식;이만형
    • Journal of Korean Port Research
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    • v.15 no.1
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    • pp.37-46
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    • 2001
  • Fuzzy logic control(FLC) is composed of three parts : fuzzy rule-bases, membership functions, and scaling factors. Well-defined fuzzy rule-base should contain proper physical intuition on the plant, so are needed lots of experiences of the skillful expert. When membership functions are considered, some parameters on the memberships function such as function shape, support, allocation density should be selected well. The rule of scaling factors is 'scaling'(amplifying or reducing) for both input and output signals of the FLC to fit in the membership function support and to operate the plant intentionally. To get a better performance of the FLC, it is necessary to adjust the parameters of the FLC. In general, the adaptation of the scaling factors is the most effective adjustment scheme, compared with that of the fuzzy rule-base or membership function parameters. This study proposes the adaptation scheme of the scaling factors. When the adaptation is performed on-line, the stability of the adaptive FLC should be guaranteed. The stable FLC system can be designed with stability analysis in the sense of Lyapunov stability. To adapt the scaling factors for the error signals, the concept of the conventional MRAC would be introduced into slightly modified form. A tracking accuracy of the control system would be enhanced by the modified shape and support of the membership function. The simulation is achieved on the pilot plant with the hydraulic steering control of a UCT(Unmanned Container Transporter) of which modeling dynamics have lots of severe uncertainties and modeling errors.

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Fuzzy control with auto-tuning scaling factor (스켈링 계수 자동조정을 통한 퍼지제어)

  • 정명환;정희태;전기준
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.123-128
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    • 1992
  • This paper presents an autotuning algorithm of scaling factor in order to improve system performance. We define the scaling factor of fuzzy controller as a function of error and error change. This function is tuned by the output of performance evaluation level utilizing the error of overshoot and rising time. Simulation results show that the proposed algorithm has good tuning performance for a system with parameter change.

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A study on Deep Q-Networks based Auto-scaling in NFV Environment (NFV 환경에서의 Deep Q-Networks 기반 오토 스케일링 기술 연구)

  • Lee, Do-Young;Yoo, Jae-Hyoung;Hong, James Won-Ki
    • KNOM Review
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    • v.23 no.2
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    • pp.1-10
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    • 2020
  • Network Function Virtualization (NFV) is a key technology of 5G networks that has the advantage of enabling building and operating networks flexibly. However, NFV can complicate network management because it creates numerous virtual resources that should be managed. In NFV environments, service function chaining (SFC) composed of virtual network functions (VNFs) is widely used to apply a series of network functions to traffic. Therefore, it is required to dynamically allocate the right amount of computing resources or instances to SFC for meeting service requirements. In this paper, we propose Deep Q-Networks (DQN)-based auto-scaling to operate the appropriate number of VNF instances in SFC. The proposed approach not only resizes the number of VNF instances in SFC composed of multi-tier architecture but also selects a tier to be scaled in response to dynamic traffic forwarding through SFC.

A Study on Non-Metric Multidimensional Scaling Using A New Fitness Function (새로운 적합도 함수를 사용한 비계량형 다차원 척도법에 대한 연구)

  • Lee, Dong-Ju;Lee, Chang-Yong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.34 no.2
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    • pp.60-67
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    • 2011
  • Since the non-metric Multidimensional scaling (nMDS), a data visualization technique, provides with insights about engineering, economic, and scientific applications, it is widely used for analyzing large non-metric multidimensional data sets. The nMDS requires a fitness function to measure fit of the proximity data by the distances among n objects. Most commonly used fitness functions are nonlinear and have a difficulty to find a good configuration. In this paper, we propose a new fitness function, an absolute value type, and show its advantages.

Wavelet Generation and It's Application in Gravity Potential (중력 포텐셜에서의 웨이브렛 생성과 응용)

  • Kim, Sam-Tai;Jin, Hong-Sung;Rim, Hyoung-Rae
    • Journal of the Korean earth science society
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    • v.25 no.2
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    • pp.109-114
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    • 2004
  • A wavelet method is applied to the analysis of gravity potential. One scaling function is proposed to generate wavelet. The scaling function is shown to be replaced to the Green’s function in gravity potential. The upward continuation can be expressed as a wavelet transform i.e. convolution with the scaling function. The scaling factor indicates the height variation. The multiscale edge detection is carried by connecting the local maxima of the wavelet transform at scales. The multiscale edge represents discontinuity of the geological structure. The multiscale edge method is applied to gravity data from Masan and Changwon.

Design of the Structure for Scaling-Wavelet Neural Network Using Genetic Algorithm (유전 알고리즘을 이용한 스케일링-웨이블릿 복합 신경회로망 구조 설계)

  • 김성주;서재용;연정흠;김성현;전홍태
    • Proceedings of the IEEK Conference
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    • 2001.06c
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    • pp.25-28
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    • 2001
  • RBFN has some problem that because the basis function isn't orthogonal to each others the number of used basis function goes to big. In this reason, the Wavelet Neural Network which uses the orthogonal basis function in the hidden node appears. In this paper, we propose the composition method of the actual function in hidden layer with the scaling function which can represent the region by which the several wavelet can be represented. In this method, we can decrease the size of the network with the pure several wavelet function. In addition to, when we determine the parameters of the scaling function we can process rough approximation and then the network becomes more stable. The other wavelets can be determined by the global solutions which is suitable for the suggested problem using the genetic algorithm and also, we use the back-propagation algorithm in the learning of the weights. In this step, we approximate the target function with fine tuning level. The complex neural network suggested In this paper is a new structure and important simultaneously in the point of handling the determination problem in the wavelet initialization.

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A Study on Performance Analysis for Error Probability in SWSK Systems

  • Jeong, Tae-Il;Moon, Kwang-Seok;Kim, Jong-Nam
    • Journal of information and communication convergence engineering
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    • v.9 no.5
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    • pp.556-561
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    • 2011
  • This paper presents a new method for shift keying using the combination of scaling function and wavelet named scaling wavelet shift keying (SWSK). An algorithm for SWSK modulation is carried out where the scaling function and the wavelet are encoded to 1 and 0 in accordance with the binary input, respectively. Signal energy, correlation coefficient and error probability of SWSK are derived from error probability of frequency shift keying(FSK). The performance is analyzed in terms of error probability and it is simulated in accordance with the kind of the wavelet. Based on the results, we can conclude that the proposed scheme is superior to the performance of the conventional schemes.

Analysis and Tuninig of Scaling Factors of Fuzzy Logic Controller (퍼지논리 제어기의 scaling factor의 분석 및 동조)

  • Lee, Chul-Heui;Kim, Kwang-Ho
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.717-719
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    • 1995
  • In this paper, we analyze the effects of scaling factors on the performance of a fuzzy controller and propose the tuning method for them. The quantitative relation between input and output variables of a fuzzy controller is obtained by using a quasi-linear fuzzy model. An approximate transfer function of a fuzzy controller is derived from the comparison a fuzzy controller with the conventional PID controller. We analyze the effects of scaling factor using this approximate transfer function and propose a fuzzy tuning method based on that of Maeda et al[4].

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