• Title/Summary/Keyword: radial basis function(RBF)

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Robust Digital Image Watermarking Algorithm Using RBF Neural Networks in DWT domain

  • Piao, Cheng-Ri;Guan, Qiang;Choi, Jun-Rim;Han, Seung-Soo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.7 no.2
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    • pp.143-147
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    • 2007
  • This paper proposes a new watermarking scheme in which a logo watermark is embedded into the discrete wavelet transform (DWT) domain of the original image using exact radial basis function neural networks (RBF). RBF will learn the characteristics of the image, and then watermark is embedded and extracted by the trained RBF. A watermark is added to the coefficients at the low frequency band of the DWT of an image and a watermark is embedded into the DWT domain using the trained RBF. The trained RBF also used in watermark extracting process. Experimental results show that the proposed method has good imperceptibility and high robustness to common image processing attacks.

Approximation of Green Warranty Function by Radon Radial Basis Function Network (Radon RBF Network에 의해 그린 보증 함수의 근사화)

  • Lee, Sang-Hyun;Lim, Jong-Han;Moon, Kyung-Li
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.123-131
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    • 2012
  • As the price of traditional fuels soar, the alternatives are becoming more viable. And manufacturers are promoting the growing viability of electric and biofuel-powered vehicles through longer warranties. Now, these longer green environment (emission)warranties, sometimes called extended warranties or "super warranties," have been adapted. The main result of this paper is to present a new method to approximate a bivariate warranty function by using Radial Basis Function Network with application of Radon Transform and its inverse which is used to reduce the dimension of the warranty space. This method consist of the following stages: First, by using the Radon Transform, the bivariate warranty function can be reduced to one dimensional function. Second, each of the one dimensional functions is approximated by using neural network technique into neural sub-networks. Third, these neural sub-networks are combined together to form the final approximation neural network. Four, by using the inverse of radon transform to this final approximation neural network we get the approximation to the given function. Also, we apply the above method to some green warranty data of automotive vehicle company.

Development of Direct Optimization Algorithms using Radial Basis Functions (방사상 기본 함수를 사용한 직접최적화 알고리즘에 관한 연구)

  • Hyeon Cheol Gong
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.5
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    • pp.600-607
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    • 1998
  • 일반적인 비선형 동역학 최적화문제를 비선형 프로그래밍 문제로 변환하는데 제어변수들을 방사성 기본 함수로 근사화하는 방법이 사용되었다. 방사성 기본 함수의 계수들을 연속적으로 보정하기 위하여 최소수정기법에 기초를 둔 비선형 프로그래밍 알고리즘이 연구되었다. 이러한 알고리즘을 실제적인 다변수 제어 시스템에 적용하여 성능을 검증하였다.

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Hydrological Forecasting Based on Hybrid Neural Networks in a Small Watershed (중소하천유역에서 Hybrid Neural Networks에 의한 수문학적 예측)

  • Kim, Seong-Won;Lee, Sun-Tak;Jo, Jeong-Sik
    • Journal of Korea Water Resources Association
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    • v.34 no.4
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    • pp.303-316
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    • 2001
  • In this study, Radial Basis Function(RBF) Neural Networks Model, a kind of Hybrid Neural Networks was applied to hydrological forecasting in a small watershed. RBF Neural Networks Model has four kinds of parameters in it and consists of unsupervised and supervised training patterns. And Gaussian Kernel Function(GKF) was used among many kinds of Radial Basis Functions(RBFs). K-Means clustering algorithm was applied to optimize centers and widths which ate the parameters of GKF. The parameters of RBF Neural Networks Model such as centers, widths weights and biases were determined by the training procedures of RBF Neural Networks Model. And, with these parameters the validation procedures of RBF Neural Networks Model were carried out. RBF Neural Networks Model was applied to Wi-Stream basin which is one of the IHP Representative basins in South Korea. 10 rainfall events were selected for training and validation of RBF Neural Networks Model. The results of RBF Neural Networks Model were compared with those of Elman Neural Networks(ENN) Model. ENN Model is composed of One Step Secant BackPropagation(OSSBP) and Resilient BackPropagation(RBP) algorithms. RBF Neural Networks shows better results than ENN Model. RBF Neural Networks Model spent less time for the training of model and can be easily used by the hydrologists with little background knowledge of RBF Neural Networks Model.

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Blind Nonlinear Channel Equalization by Performance Improvement on MFCM (MFCM의 성능개선을 통한 블라인드 비선형 채널 등화)

  • Park, Sung-Dae;Woo, Young-Woon;Han, Soo-Whan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.11
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    • pp.2158-2165
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    • 2007
  • In this paper, a Modified Fuzzy C-Means algorithm with Gaussian Weights(MFCM_GW) is presented for nonlinear blind channel equalization. The proposed algorithm searches the optimal channel output states of a nonlinear channel from the received symbols, based on the Bayesian likelihood fitness function and Gaussian weighted partition matrix instead of a conventional Euclidean distance measure. Next, the desired channel states of a nonlinear channel are constructed with the elements of estimated channel output states, and placed at the center of a Radial Basis Function(RBF) equalizer to reconstruct transmitted symbols. In the simulations, binary signals are generated at random with Gaussian noise. The performance of the proposed method is compared with those of a simplex genetic algorithm(GA), a hybrid genetic algorithm(GA merged with simulated annealing(SA): GASA), and a previously developed version of MFCM. It is shown that a relatively high accuracy and fast search speed has been achieved.

A Study on Three Phase Partial Discharge Pattern Classification with the Aid of Optimized Polynomial Radial Basis Function Neural Networks (최적화된 pRBF 뉴럴 네트워크에 이용한 삼상 부분방전 패턴분류에 관한 연구)

  • Oh, Sung-Kwun;Kim, Hyun-Ki;Kim, Jung-Tae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.4
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    • pp.544-553
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    • 2013
  • In this paper, we propose the pattern classifier of Radial Basis Function Neural Networks(RBFNNs) for diagnosis of 3-phase partial discharge. Conventional methods map the partial discharge/noise data on 3-PARD map, and decide whether the partial discharge occurs or not from 3-phase or neutral point. However, it is decided based on his own subjective knowledge of skilled experter. In order to solve these problems, the mapping of data as well as the classification of phases are considered by using the general 3-PARD map and PA method, and the identification of phases occurring partial discharge/noise discharge is done. In the sequel, the type of partial discharge occurring on arbitrary random phase is classified and identified by fuzzy clustering-based polynomial Radial Basis Function Neural Networks(RBFNN) classifier. And by identifying the learning rate, momentum coefficient, and fuzzification coefficient of FCM fuzzy clustering with the aid of PSO algorithm, the RBFNN classifier is optimized. The virtual simulated data and the experimental data acquired from practical field are used for performance estimation of 3-phase partial discharge pattern classifier.

Optimization of FCM-based Radial Basis Function Neural Network Using Particle Swarm Optimization (PSO를 이용한 FCM 기반 RBF 뉴럴 네트워크의 최적화)

  • Choi, Jeoung-Nae;Kim, Hyun-Ki;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.11
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    • pp.2108-2116
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    • 2008
  • The paper concerns Fuzzy C-Means clustering based Radial Basis Function neural networks (FCM-RBFNN) and the optimization of the network is carried out by means of Particle Swarm Optimization(PSO). FCM-RBFNN is the extended architecture of Radial Basis Function Neural Network(RBFNN). In the proposed network, the membership functions of the premise part of fuzzy rules do not assume any explicit functional forms such as Gaussian, ellipsoidal, triangular, etc., so its resulting fitness values directly rely on the computation of the relevant distance between data points by means of FCM. Also, as the consequent part of fuzzy rules extracted by the FCM - RBFNN model, the order of four types of polynomials can be considered such as constant, linear, quadratic and modified quadratic. Weighted Least Square Estimator(WLSE) are used to estimates the coefficients of polynomial. Since the performance of FCM-RBFNN is affected by some parameters of FCM-RBFNN such as a specific subset of input variables, fuzzification coefficient of FCM, the number of rules and the order of polynomials of consequent part of fuzzy rule, we need the structural as well as parametric optimization of the network. In this study, the PSO is exploited to carry out the structural as well as parametric optimization of FCM-RBFNN. Moreover The proposed model is demonstrated with the use of numerical example and gas furnace data set.

A Study on Speaker-Independent Speech Recognition Using a Hybrid System of Semi-Continuous HMM and RBF (반연속 HMM과 RBF 혼합 시스템을 이용한 화자독립 음성인식에 관한 연구)

  • Moon Yun Joo;June Sun Do;Kang Chul Ho
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.36-39
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    • 1999
  • 본 논문에서는 기존의 반연속 HMM과 신경망 알고리즘인 RBF(Radial Basis Function)를 혼합한 형태를 음성인식에 적용한다. 기존의 반연속 HMM은 학습 과정에서 모든 모델과 상태에서 공유되는 L개의 가우시안 확률 밀도들과 각가우시안 확률 밀도들의 가중치를 결정하는 흔합 밀도계수 의해 입력 음성의 특징을 확률적으로 모델링하는 혼합 확률을 얻고 또 Maximum likelihood와 Baum-Welch 알고리즘을 이용해 초기확률, 전이확률, 관측확률, 평균벡터 $\mu$, 공분산 행렬 $\Sigma$을 학습해 나간다. 그러나 제안한 RBF/반연속 HMM 혼합형태는 RBF의 변형된 방식을 첨가해 반연속 HMM 관측 파라미터를 RBF에 의해 결정함으로써 보단 분별릭 있는 화자독립 인식 시스템이 된다. 그래서 인식 실험결과 인식률에 있어서 기존의 반연속 HMM보다 향상된 인식률을 얻는다.

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An On-line Construction of Generalized RBF Networks for System Modeling (시스템 모델링을 위한 일반화된 RBF 신경회로망의 온라인 구성)

  • Kwon, Oh-Shin;Kim, Hyong-Suk;Choi, Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.37 no.1
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    • pp.32-42
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    • 2000
  • This paper presents an on-line learning algorithm for sequential construction of generalized radial basis function networks (GRBFNs) to model nonlinear systems from empirical data. The GRBFN, an extended from of standard radial basis function (RBF) networks with constant weights, is an architecture capable of representing nonlinear systems by smoothly integrating local linear models. The proposed learning algorithm has a two-stage learning scheme that performs both structure learning and parameter learning. The structure learning stage constructs the GRBFN model using two construction criteria, based on both training error criterion and Mahalanobis distance criterion, to assign new hidden units and the linear local models for given empirical training data. In the parameter learning stage the network parameters are updated using the gradient descent rule. To evaluate the modeling performance of the proposed algorithm, simulations and their results applied to two well-known benchmarks are discussed.

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A vibration-based approach for detecting arch dam damage using RBF neural networks and Jaya algorithms

  • Ali Zar;Zahoor Hussain;Muhammad Akbar;Bassam A. Tayeh;Zhibin Lin
    • Smart Structures and Systems
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    • v.32 no.5
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    • pp.319-338
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    • 2023
  • The study presents a new hybrid data-driven method by combining radial basis functions neural networks (RBF-NN) with the Jaya algorithm (JA) to provide effective structural health monitoring of arch dams. The novelty of this approach lies in that only one user-defined parameter is required and thus can increase its effectiveness and efficiency, as compared to other machine learning techniques that often require processing a large amount of training and testing model parameters and hyper-parameters, with high time-consuming. This approach seeks rapid damage detection in arch dams under dynamic conditions, to prevent potential disasters, by utilizing the RBF-NNN to seamlessly integrate the dynamic elastic modulus (DEM) and modal parameters (such as natural frequency and mode shape) as damage indicators. To determine the dynamic characteristics of the arch dam, the JA sequentially optimizes an objective function rooted in vibration-based data sets. Two case studies of hyperbolic concrete arch dams were carefully designed using finite element simulation to demonstrate the effectiveness of the RBF-NN model, in conjunction with the Jaya algorithm. The testing results demonstrated that the proposed methods could exhibit significant computational time-savings, while effectively detecting damage in arch dam structures with complex nonlinearities. Furthermore, despite training data contaminated with a high level of noise, the RBF-NN and JA fusion remained the robustness, with high accuracy.