• Title/Summary/Keyword: fuzzy time series

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On Chaotic Behavior of Fuzzy Inferdence Rule Based Nonlinear Functions

  • Ikoma, Norikazu
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.861-864
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    • 1993
  • This research provides the results of a trial to generate the chaos by using nonlinear function constructed by fuzzy inference rules. The chaos generation function or chaotic behavior can be obtained by using Takagi-Sugeno fuzzy model with some constraint of the relationship of its parameters. Two examples are shown in this research. The first is simple example that construct of logistic image by fuzzy model. The second is more complicated one that provide the chaotic time series by non-linear autoregression based on fuzzy model. Simulated results are shown in these examples.

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Real-Time Peak Shaving Algorithm Using Fuzzy Wind Power Generation Curves for Large-Scale Battery Energy Storage Systems

  • Son, Subin;Song, Hwachang
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.14 no.4
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    • pp.305-312
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    • 2014
  • This paper discusses real-time peak shaving algorithms for a large-scale battery energy storage system (BESS). Although several transmission and distribution functions could be implemented for diverse purposes in BESS applications, this paper focuses on a real-time peak shaving algorithm for an energy time shift, considering wind power generation. In a high wind penetration environment, the effective load levels obtained by subtracting the wind generation from the load time series at each long-term cycle time unit are needed for efficient peak shaving. However, errors can exist in the forecast load and wind generation levels, and the real-time peak shaving operation might require a method for wind generation that includes comparatively large forecasting errors. To effectively deal with the errors of wind generation forecasting, this paper proposes a real-time peak shaving algorithm for threshold value-based peak shaving that considers fuzzy wind power generation.

3D Radar Objects Tracking and Reflectivity Profiling

  • Kim, Yong Hyun;Lee, Hansoo;Kim, Sungshin
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.12 no.4
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    • pp.263-269
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    • 2012
  • The ability to characterize feature objects from radar readings is often limited by simply looking at their still frame reflectivity, differential reflectivity and differential phase data. In many cases, time-series study of these objects' reflectivity profile is required to properly characterize features objects of interest. This paper introduces a novel technique to automatically track multiple 3D radar structures in C,S-band in real-time using Doppler radar and profile their characteristic reflectivity distribution in time series. The extraction of reflectivity profile from different radar cluster structures is done in three stages: 1. static frame (zone-linkage) clustering, 2. dynamic frame (evolution-linkage) clustering and 3. characterization of clusters through time series profile of reflectivity distribution. The two clustering schemes proposed here are applied on composite multi-layers CAPPI (Constant Altitude Plan Position Indicator) radar data which covers altitude range of 0.25 to 10 km and an area spanning over hundreds of thousands $km^2$. Discrete numerical simulations show the validity of the proposed technique and that fast and accurate profiling of time series reflectivity distribution for deformable 3D radar structures is achievable.

Fuzzy PID Control of Warranty Claims Time Series (보증 클레임 시계열 데이터를 위한 퍼지 PID 제어)

  • Lee, Sang-Hyun;Lee, Sang-Joon;Moon, Kyung-Il;Cho, Sung-Eui
    • Journal of Information Technology Services
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    • v.8 no.4
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    • pp.175-185
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    • 2009
  • Objectifying claims filed during the warranty period, analyzing the current circumstances and improving on the problem in question is an activity worth doing that could reduce the likelihood of claims to occur, cut down on the costs, and enhance the corporate image of the manufacturer. Existing analyses of claims are confronted with two problems. First, you can't precisely assess the risks of claims involved by means of the value of claims per 100 products alone. Second, even in a normal state, the existing approach fails to capture the probabilistic conflicts that escape the upper control limit of claims, thus leading to wrong control activities. To solve the first problem, this paper proposed that a time series detection concept where the claim rate is monitored based on the date when problems are processed and a hazard function for expression of the claim rate be utilized. For the second problem, this paper designed a model whereby to define a normal state by making use of PID (Proportion, Integral, Differential) and infer by way of a fuzzy concept. This paper confirmed the validity and applicability of the proposed approach by applying methods suggested in the actual past data of warranty claims of a large-scaled automotive firm, unlike hypothetical simulation data, in order to apply them directly in industrial job sites, as well as making theoretical suggestions for analysis of claims.

Design of Neuro-Fuzzy-based Predictive Controller for Nonlinear Systems with Time Delay (지연시간을 갖는 비선형 시스템을 위한 퍼지-신경망 기반 예측제어기 설계)

  • Kim, Sung-Ho;Kim, Joo-Whan;Lee, Young-Sam
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.2
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    • pp.144-150
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    • 2002
  • In this paper a design of neuro-fuzzy-based predictive controller for nonlinear systems with time-delay is proposed. The proposed control system contains two neuro-fuzzy systems called ANFIS(Adaptive Neuro-Fuzzy Inference System). One is run as a series-parallel mode and the other is run as a parallel mode. An ANFIS running in series-parallel mode emulates the response of the nonlinear system with time-delay. Another ANFIS running in parallel mode generates the predicted output of the nonlinear system to compensate for the time-delays. Therefore, the proposed control system can be thought of as an extension of Smith-predictor scheme to the nonlinear systems with time-delay. A detailed design Procedure is presented and finally computer simulations are executed for the effectiveness of the proposed control scheme.

A Study on development of short term electric load prediction system with the genetic algorithm and the fuzzy system (유전자알고리즘과 퍼지시스템을 이용한 단기부하예측 시스템 개발에 관한 연구)

  • Kang, Hwan-Il;Jang, Woo-Seok
    • Journal of the Korean Institute of Intelligent Systems
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    • v.16 no.6
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    • pp.730-735
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    • 2006
  • This paper proposes a time series prediction method for the short term electrical load will) the fuzzy system and the genetic algorithm. At first, we obtain the optimal fuzzy membership function using the genetic algorithm. With the optimal fuzzy rules and its input differences, a better time prediction system may be obtained. We obtain good results for the time prediction of the short term electric load by the proposed algorithm. In addition we implement the graphic user interface for the proposed algorithms. Finally, we implement the regional prediction system for the electric load.

Development of Fuzzy Network Performance Manager for Token Bus Factory Automation Networks (퍼지기법을 이용한 공장자동화용 토큰버스 네트워크의 성능관리)

  • 이상오
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.04b
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    • pp.471-476
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    • 1995
  • This paper focues on development and implementation of a perfomance management algorithm for IEEE802.4 token bus networks to serve large-scale integrated manufacturing systems. Such factory automation networks have to satisfy delay constraints imposed on time-critical messages while maintaining as much network capacity as possible for non-time-critical messages. This paper presents the structure of a network performance manager that possesses the knowledge about perfomance management in a set of fuzzy rules and deriving its action through fuzzy inference mechanism. The efficacy of the performance management has been demonstrated by a series of simulation experiments.

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Nonlinear Behavior Analysis in Love Model with closing awareness of Human (사람 인식에 근접한 외력을 가진 사랑 모델에서 비선형 거동 분석)

  • Bae, Young-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.1
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    • pp.201-208
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    • 2017
  • This paper propose triangular fuzzy membership function to make model that based on awareness of human in the love model that with external force, which have the basic love model of Romeo and Juliet. This paper represents the phenomena of behaviors by time series and phase portraits after using this fuzzy triangular membership function as an external force and also confirms existence of nonlinear characteristics.

Robust Fuzzy Control of a Class of Nonlinear Descriptor Systems with Time-Varying Delay

  • Yan Wang;Sun, Zeng-Qi;Sun, Fu-Chun
    • International Journal of Control, Automation, and Systems
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    • v.2 no.1
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    • pp.76-82
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    • 2004
  • A robust fuzzy controller is designed to stabilize a class of solvable nonlinear descriptor systems with time-varying delay. First, a new modeling and control method for nonlinear descriptor systems is presented with a fuzzy descriptor model. A sufficient condition for the existence of the fuzzy controller is given in terms of a series of LMIs. Then, a less conservative fuzzy controller design approach is obtained based on the fuzzy rules and weights. This method includes the interactions of the different subsystems into one matrix. The effectiveness of the presented approach and the design procedure of the fuzzy controller are illustrated by way of an example.

Intelligent Digital Redesign for Uncertain Nonlinear Systems Using Power Series (Powrer Series를 이용한 불확실성을 갖는 비선형 시스템의 지능형 디지털 재설계)

  • Sung Hwa Chang;Park Jin Bae;Go Sung Hyun;Joo Young Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.7
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    • pp.881-886
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    • 2005
  • This paper presents intelligent digital redesign method of global approach for hybrid state space fuzzy-model-based controllers. For effectiveness and stabilization of continuous-time uncertain nonlinear systems under discrete-time controller, Takagi-Sugeno(TS) fuzzy model is used to represent tile complex system. And global approach design problems viewed as a convex optimization problem that we minimize the error of the norm bounds between nonlinearly interpolated linear operators to be matched. Also, by using the power series, we analyzed nonlinear system's uncertain parts more precisely. When a sampling period is sufficiently small, the conversion of a continuous-time structured uncertain nonlinear system to an equivalent discrete-time system have proper reason. Sufficiently conditions for the global state-matching of tile digitally controlled system are formulated in terms of linear matrix inequalities (LMIs). Finally, a TS fuzzy model for the chaotic Lorentz system is used as an example to guarantee the stability and effectiveness of the proposed method.