• Title/Summary/Keyword: Fuzzy equation

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Fuzzy Analysis for Consciousness Structure of Core Competency of Manufacturing Workers (현장근로자 핵심역량의 의식구조에 대한 퍼지분석)

  • Gi, Jong-Dai;Hwang, Seung-Gook
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.3
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    • pp.378-382
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    • 2011
  • This paper develops the core competencies of manufacturing workers, analyze the consciousness structure on the core competencies. As the analyzing method of consciousness structure, ISM(Interpretive Structural Modeling) and FSM(Fuzzy Structural Modeling) are used to classify layers and determine the connection state. However, the element of each layer is frequently changed by data. This paper suggests the method with the point of view that the structure is determined basically and the connection state of the structure model is changeable depending on the method; first to determine structure model by ISM, second to determine connection by FSM. By using this method, the objective structure model, analyzing the consciousness on the core competencies of manufacturing workers, is suggested with specialist confirm.

A Case Study on the Evaluation of Environmental Health Status based on Environmental Health Indicators (환경보건지표를 이용한 지역 환경보건수준 평가 사례연구)

  • Jung, Soon-Won;Lee, Young-Mee;Hong, Sung-Joon;Chang, Jun-Young;Yu, Seung-Do;Choi, Kyung-Hee;Park, Choong-Hee
    • Journal of Environmental Health Sciences
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    • v.42 no.5
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    • pp.302-313
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    • 2016
  • Objectives: This study was conducted to assess environmental health status on a local scale using environmental health-related indicators. It demonstrated the possibility of using a structural equation model, a methodological approach to provide synthesized information. Methods: Eighteen indicators were selected from official statistical data published by local governments. Each environmental health-related indicator was classified according to the PSR (pressure-state-response) model. Aggregation methods were performed using principal component analysis and fuzzy sets. Results: The five principal components were classified through principal component analysis (PCA) and obtained eigenvalues >1.0 from the initial 18 indicators. The aggregated index was obtained by condensing the original information into two broad and simple categories through fuzzy sets. Conclusion: This could be useful in that the aggregation procedure may provide a basis for establishing environmental health policies and a decision-making process. However, the availability and quality of indicators, assessment of aggregation method bias, choice of weighted scores for indicators, and other factors should be examined in future studies.

Feature Extraction based FE-SONN for Signature Verification (서명 검증을 위한 특정 기반의 FE-SONN)

  • Koo Gun-Seo
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.6 s.38
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    • pp.93-102
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    • 2005
  • This paper proposes an approach to verify signature using autonomous self-organized Neural Network Model , fused with fuzzy membership equation of fuzzy c-means algorithm, based on the features of the signature. To overcome limitations of the functional approach and Parametric approach among the conventional on-line signature recognition approaches, this Paper presents novel autonomous signature classification approach based on clustering features. Thirty-six globa1 features and twelve local features were defined, so that a signature verifying system with FE-SONN that learns them was implemented. It was experimented for total 713 signatures that are composed of 155 original signatures and 180 forged signatures yet 378 original signatures written by oneself. The success rate of this test is more than 97.67$\%$ But, a few forged signatures that could not be detected by human eyes could not be done by the system either.

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Research on Speed Estimation Method of Induction Motor based on Improved Fuzzy Kalman Filtering

  • Chen, Dezhi;Bai, Baodong;Du, Ning;Li, Baopeng;Wang, Jiayin
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.3
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    • pp.272-275
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    • 2014
  • An improved fuzzy Kalman filtering speed estimation scheme was proposed by means of measuring stator side voltage and current value based on vector control state equation of induction motor. The designed fuzzy adaptive controller conducted recursive online correction of measurement noise covariance matrix by monitoring the ratio of theory residuals and actual residuals to make it approach real noise level gradually, allowing the filter to perform optimal estimation to improve estimation accuracy of EKF. Meanwhile, co-simulation scheme based on MATLAB and Ansoft was proposed in order to improve simulation accuracy. Field-circuit coupling problems of induction motor under the action of vector control were solved and the parameter optimization accuracy was improved dramatically. The simulation and experimental results show that this algorithm has a strong ability to inhibit the random measurement noise. It is able to estimate motor speed accurately, and has superior static and dynamic characteristics.

Intelligent Range Decision Method for Figure of Merit of Sonar Equation (소나 방정식 성능지수의 지능형 거리 판단기법)

  • Son, Hyun Seung;Park, Jin Bae;Joo, Young Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.4
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    • pp.304-309
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    • 2013
  • This paper proposes a intelligent approach on range decision of figure of merit. Unknown range of the underwater target and the non-fixed signal excess make the uncertainty for the tracking process. Using the input data of signal excess related to the range, we establish the rule of the fuzzy set and the original data acquired by sonar can be transformed to the fuzzified data set. To reduce the error arisen from the unexpected data, we use the new data transformed in fuzzy set. The piecewise relations of the min value, max one, and the mean one are calculated. The three values are used for the expected range of the underwater target. By analysing the fluctuation of the data, we can expect the target's position and the characteristics of the maneuvering. The examples are presented to show the performance and the effectiveness of the proposed method.

Nonlinear intelligent control systems subjected to earthquakes by fuzzy tracking theory

  • Z.Y. Chen;Y.M. Meng;Ruei-Yuan Wang;Timothy Chen
    • Smart Structures and Systems
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    • v.33 no.4
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    • pp.291-300
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    • 2024
  • Uncertainty of the model, system delay and drive dynamics can be considered as normal uncertainties, and the main source of uncertainty in the seismic control system is related to the nature of the simulated seismic error. In this case, optimizing the management strategy for one particular seismic record will not yield the best results for another. In this article, we propose a framework for online management of active structural management systems with seismic uncertainty. For this purpose, the concept of reinforcement learning is used for online optimization of active crowd management software. The controller consists of a differential controller, an unplanned gain ratio, the gain of which is enhanced using an online reinforcement learning algorithm. In addition, the proposed controller includes a dynamic status forecaster to solve the delay problem. To evaluate the performance of the proposed controllers, thousands of ground motion data sets were processed and grouped according to their spectrum using fuzzy clustering techniques with spatial hazard estimation. Finally, the controller is implemented in a laboratory scale configuration and its operation is simulated on a vibration table using cluster location and some actual seismic data. The test results show that the proposed controller effectively withstands strong seismic interference with delay. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings, sustainable human settlement planning and manage. Simulation results is believed to achieved in the near future by the ongoing development of AI and control theory.

Filling of Incomplete Rainfall Data Using Fuzzy-Genetic Algorithm (퍼지-유전자 알고리즘을 이용한 결측 강우량의 보정)

  • Kim, Do Jin;Jang, Dae Won;Seoh, Byung Ha;Kim, Hung Soo
    • Journal of Wetlands Research
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    • v.7 no.4
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    • pp.97-107
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    • 2005
  • As the distributed model is developed and widely used, the accuracy of a rainfall measurement and more dense rainfall observation network are required for the reflection of various spatial properties. However, in reality, it is not easy to get the accurate data from dense network. Generally, we could not have the proper rainfall gages in space and even we have proper network for rainfall gages it is not easy to reflect the variations of rainfall in space and time. Often, we do also have missing rainfall data at the rainfall gage stations due to various reasons. We estimate the distribution of mean areal rainfall data from the point rainfalls. So, in the aspect of continuous rainfall property in time, we should fill the missing rainfall data then we can represent the spatial distribution of rainfall data. This study uses the Fuzzy-Genetic algorithm as a interpolation method for filling the missing rainfall data. We compare the Fuzzy-Genetic algorithm with arithmetic average method, inverse distance method, normal ratio method, and ratio of distance and elevation method which are widely used previously. As the results, the previous methods showed the accuracy of 70 to 80 % but the Fuzzy-Genetic algorithm showed that of 90 %. Especially, from the sensitivity analysis, we suggest the values of power in the equation for filling the missing data according to the distance and elevation.

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The Digital Loyalty Equation in Distribution Science: A Multi-method Exploration of E-commerce Success Factors

  • Vu Hiep HOANG;Quoc Dung NGO;Anh Kiet MAI;Huynh Mai LE
    • Journal of Distribution Science
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    • v.22 no.9
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    • pp.13-25
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    • 2024
  • Purpose: This study explores the complex interplay between service quality, customer engagement, and loyalty in the e-commerce sector, examining the moderating effect of technological adoption on these crucial relationships. Research design, data and methodology: Employing a robust multi-method approach, the research analyzes data from 481 e-commerce users, leveraging the complementary strengths of partial least squares structural equation modeling (PLS-SEM) and fuzzy-set qualitative comparative analysis(fsQCA). Acomprehensive multi-group analysisis conducted to uncover differences between experienced and non-experienced users. Results: PLS-SEM reveals that service quality significantly influences customer engagement, which in turn drives loyalty. Technological adoption positively moderates the service quality-engagement relationship. The multi-group analysis uncovers notable differences between user segments. fsQCA identifies two distinct configurational paths consistently leading to high customer loyalty: high customer engagement and high service quality. Conclusions: This study's innovative integration of PLS-SEM and fsQCA contributes to a deeper understanding of the intricate dynamics driving e-commerce success. Findings provide actionable insights for e-commerce businesses to enhance service quality, foster engagement, and cultivate loyalty. This research lays the groundwork for further exploration of these critical relationships in different contexts, offering a nuanced perspective on the complex interplay of factors shaping customer behavior in the digital marketplace.

A study on the Adaptive Controller with Chaotic Dynamic Neural Networks

  • Kim, Sang-Hee;Ahn, Hee-Wook;Wang, Hua O.
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.7 no.4
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    • pp.236-241
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    • 2007
  • This paper presents an adaptive controller using chaotic dynamic neural networks(CDNN) for nonlinear dynamic system. A new dynamic backpropagation learning method of the proposed chaotic dynamic neural networks is developed for efficient learning, and this learning method includes the convergence for improving the stability of chaotic neural networks. The proposed CDNN is applied to the system identification of chaotic system and the adaptive controller. The simulation results show good performances in the identification of Lorenz equation and the adaptive control of nonlinear system, since the CDNN has the fast learning characteristics and the robust adaptability to nonlinear dynamic system.

Verification of a hybrid control approach for spacecraft attitude stabilization through hardware-in-the-loop simulation

  • Kim, Sung-Woo;Park, Sang-Young
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.32.2-32.2
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    • 2011
  • State dependent Riccati equation (SDRE) control technique has been widely used in the control society. Although it solves nonlinear optimal control problems, which minimizes state error and control efforts simultaneously, it has drawbacks when it is to be applied to the real time systems in that it requires much computational efforts. So the real time system whose computational ability is limited (for example, satellites) cannot afford to use SDRE controller. To solve this problem, a hybrid controller which is based on MSDRE (Modified SDRE) and ANFIS (Adaptive Neuro-Fuzzy Inference System) has been proposed by Abdelrahman et al. (2010). We propose a hybrid controller based on SDRE and ANFIS, and apply the hybrid controller to the hardware attitude simulator to perform a HIL (Hardware-In-the-Loop) simulation. Through HIL simulation, it is demonstrated that the hybrid controller satisfies the control requirement and the computation load is reduced significantly. In addition, the effects of statistical properties of the ANFIS training data to the performance of the ANFIS controller have been analyzed.

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