• 제목/요약/키워드: High-order polynomial model

검색결과 89건 처리시간 0.041초

하이브리드 퍼지뉴럴네트워크의 알고리즘과 구조 (Algorithm and Architecture of Hybrid Fuzzy Neural Networks)

  • 박병준;오성권;김현기
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.372-372
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    • 2000
  • In this paper, we propose Neuro Fuzzy Polynomial Networks(NFPN) based on Polynomial Neural Network(PNN) and Neuro-Fuzzy(NF) for model identification of complex and nonlinear systems. The proposed NFPN is generated from the mutually combined structure of both NF and PNN. The one and the other are considered as the premise part and consequence part of NFPN structure respectively. As the premise part of NFPN, NF uses both the simplified fuzzy inference as fuzzy inference method and error back-propagation algorithm as learning rule. The parameters such as parameters of membership functions, learning rates and momentum coefficients are adjusted using genetic algorithms. As the consequence part of NFPN, PNN is based on Group Method of Data Handling(GMDH) method and its structure is similar to Neural Networks. But the structure of PNN is not fixed like in conventional Neural Networks and self-organizing networks that can be generated. NFPN is available effectively for multi-input variables and high-order polynomial according to the combination of NF with PNN. Accordingly it is possible to consider the nonlinearity characteristics of process and to get better output performance with superb predictive ability. In order to evaluate the performance of proposed models, we use the nonlinear function. The results show that the proposed FPNN can produce the model with higher accuracy and more robustness than any other method presented previously.

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PATCHWISE REPRODUCING POLYNOMIAL PARTICLE METHOD FOR THICK PLATES: BENDING, FREE VIBRATION, AND BUCKLING

  • Kim, Hyunju;Jang, Bongsoo
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제17권2호
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    • pp.67-85
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    • 2013
  • Reproducing Polynomial Particle Method (RPPM) is one of meshless methods that use meshes minimally or do not use meshes at all. In this paper, the RPPM is employed for free vibration analysis of shear-deformable plates of the first order shear deformation model (FSDT), called Reissner-Mindlin plate. For numerical implementation, we use flat-top partition of unity functions, introduced by Oh et al, and patchwise RPPM in which approximation functions have high order polynomial reproducing property and the Kronecker delta property. Also, we demonstrate that our method is highly effective than other existing results for various aspect ratios and boundary conditions.

전치왜곡기로 인한 고속이동통신의 성능향상기법 (Performance improvement of the high speed mobile communication by the predistorter)

  • 이강미;신덕호;김백현;이준호
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.173-174
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    • 2006
  • High power amplifier (HPA), which is used in transmitter of wireless communication systems, usually works in near saturation point in order to achieve maximum efficiency. In this region, HPA can introduce undesirable nonlinear effects. In this paper, we present a polynomial modeling method for efficient techniques to compensate for nonlinear distortion introduced by nonlinear HPA. Proposed polynomial predistorter inverses actual amplifier. Namely, we derive polynomials of amplifiers from analytical method and the electrical parameters in the data sheet of an actual amplifier and then can derive polynomial predistorter by inversing them. It is an effective and a simple method to compensate nonlinear distortion. SSPA(Solid-state power amplifier) is considered. We also analyze the effects of predistortion on the SER performance of communication system with 16-QAM modulation format. The results have shown the efficiency of this model.

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반응표면법을 이용한 DTF의 석탄 연소 안전성 평가 (Assessment of Coal Combustion Safety of DTF using Response Surface Method)

  • 이의주
    • 한국안전학회지
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    • 제30권1호
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    • pp.8-13
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    • 2015
  • The experimental design methodology was applied in the drop tube furnace (DTF) to predict the various combustion properties according to the operating conditions and to assess the coal plant safety. Response surface method (RSM) was introduced as a design of experiment, and the database for RSM was set with the numerical simulation of DTF. The dependent variables such as burnout ratios (BOR) of coal and $CO/CO_2$ ratios were mathematically described as a function of three independent variables (coal particle size, carrier gas flow rate, wall temperature) being modeled by the use of the central composite design (CCD), and evaluated using a second-order polynomial multiple regression model. The prediction of BOR showed a high coefficient of determination (R2) value, thus ensuring a satisfactory adjustment of the second-order polynomial multiple regression model with the simulation data. However, $CO/CO_2$ ratio had a big difference between calculated values and predicted values using conventional RSM, which might be mainly due to the dependent variable increses or decrease very steeply, and hence the second order polynomial cannot follow the rates. To relax the increasing rate of dependent variable, $CO/CO_2$ ratio was taken as common logarithms and worked again with RSM. The application of logarithms in the transformation of dependent variables showed that the accuracy was highly enhanced and predicted the simulation data well.

다항식 뉴럴 네트워크의 최적화: 진화론적 방법 (Optimization of Polynomial Neural Networks: An Evolutionary Approach)

  • 김동원;박귀태
    • 대한전기학회논문지:시스템및제어부문D
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    • 제52권7호
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    • pp.424-433
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    • 2003
  • Evolutionary design related to the optimal design of Polynomial Neural Networks (PNNs) structure for model identification of complex and nonlinear system is studied in this paper. The PNN structure is consisted of layers and nodes like conventional neural networks but is not fixed and can be changable according to the system environments. three types of polynomials such as linear, quadratic, and modified quadratic is used in each node that is connected with various kinds of multi-variable inputs. Inputs and order of polynomials in each node are very important element for the performance of model. In most cases these factors are decided by the background information and trial and error of designer. For the high reliability and good performance of the PNN, the factors must be decided according to a logical and systematic way. In the paper evolutionary algorithm is applied to choose the optimal input variables and order. Evolutionary (genetic) algorithm is a random search optimization technique. The evolved PNN with optimally chosen input variables and order is not fixed in advance but becomes fully optimized automatically during the identification process. Gas furnace and pH neutralization processes are used in conventional PNN version are modeled. It shows that the designed PNN architecture with evolutionary structure optimization can produce the model with higher accuracy than previous PNN and other works.

다항식 뉴럴 네트워크의 최적화 : 진화론적 방법 (Optimization of Polynomial Neural Networks: An Evolutionary Approach)

  • 김동원;박귀태
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권7호
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    • pp.424-424
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    • 2003
  • Evolutionary design related to the optimal design of Polynomial Neural Networks (PNNs) structure for model identification of complex and nonlinear system is studied in this paper. The PNN structure is consisted of layers and nodes like conventional neural networks but is not fixed and can be changable according to the system environments. three types of polynomials such as linear, quadratic, and modified quadratic is used in each node that is connected with various kinds of multi-variable inputs. Inputs and order of polynomials in each node are very important element for the performance of model. In most cases these factors are decided by the background information and trial and error of designer. For the high reliability and good performance of the PNN, the factors must be decided according to a logical and systematic way. In the paper evolutionary algorithm is applied to choose the optimal input variables and order. Evolutionary (genetic) algorithm is a random search optimization technique. The evolved PNN with optimally chosen input variables and order is not fixed in advance but becomes fully optimized automatically during the identification process. Gas furnace and pH neutralization processes are used in conventional PNN version are modeled. It shows that the designed PNN architecture with evolutionary structure optimization can produce the model with higher accuracy than previous PNN and other works.

위성영상의 DEM 생성을 위한 영상분할 방법의 적합성 평가 (Evaluation of The Image Segmentation Method for DEM Generation of Satellite Imagery)

  • 이효성;송정헌;김용일;안기원
    • 대한원격탐사학회지
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    • 제19권2호
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    • pp.149-157
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    • 2003
  • 본 연구에서는 향후 지속적으로 제공되어질 고해상도 위성영상의 효율적인 대체 센서모델링을 위하여 SPOT-3호의 위성영상으로부터 대상영역에 영상분할을 실시하고 분할된 영상으로부터 분모항이 없는 RFM 즉, 3차 다항식 모델의 적용성을 고찰하였다. 대상영역 전체에 적용한 분모항이 있는 기존 RFM의 적합도와 비교한 결과, 평면오차는 3차 다항식 모델링 방법이 0.8m 정도 낮게 산출된 반면 표고오차는 기존의 RFM이 1.0m 정도 낮게 산출되었다.

고해상도 인공위성 영상데이터의 기하보정을 위한 RFM의 적용 (The Application of RFM for Geometric Correction of High-Resolution Satellite Image Data)

  • 안기원;임환철;서두천
    • 한국측량학회지
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    • 제20권2호
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    • pp.155-164
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    • 2002
  • 본 연구에서는 상업용 고해상도 위성인 IKONOS 위성 영상의 기하보정 방법에 대해 알아보기 위해 기존에 쓰여왔던 다항식모델과 위성의 보조데이터 없이 기하보정이 가능한 RM을 적용하여 각각의 차수와 기준점의 수에 따른 정확도를 비교 분석하였다. 또한 RFM 계수산출을 위한 최소제곱법의 수치적 불안정성을 극복하기 위하여 Tikhonov 정규화기법을 도입하여 적용하였다. RFM 적응 결과, 기존의 2차원 다항식 모델에 비해 평균제곱근오차를 2 pixel 이상 감소시킬 수 있었다.

비선형 공정을 위한 최적 다항식 뉴럴네트워크에 관한 연구 (A Study on Optimal Polynomial Neural Network for Nonlinear Process)

  • 김완수;오성권;김현기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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    • pp.149-151
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    • 2005
  • In this paper, we propose the Optimal Polynomial Neural Networks(PNN) for nonlinear process. The PNN is based on Group Method of Data Handling(GMDH) method and its structure is similar to feedforward Neural Networks. But the structure of PNN is not fixed like in conventional Neural Networks and can be generated. The each node of PNN structure uses several types of high-order polynomial such as linear, quadratic and modified quadratic, and is connected as various kinds of multi-variable inputs. The conventional PNN depends on experience of a designer that select No. of input variable, input variable and polynomial type. Therefore it is very difficult a organizing of optimized network. The proposed algorithm identified and selected No. of input variable, input variable and polynomial type by using Genetic Algorithms(GAs). In the sequel the proposed model shows not only superior results to the existing models, but also pliability in organizing of optimal network. Medical Imaging System(MIS) data is simulated in order to confirm the efficiency and feasibility of the proposed approach in this paper.

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경쟁적 퍼지 다항식 뉴론을 가진 자기 구성 네트워크의 설계 (Design of Self-Organizing Networks with Competitive Fuzzy Polynomial Neuron)

  • 박호성;오성권;김현기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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    • pp.800-802
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    • 2000
  • In this paper, we propose the Self-Organizing Networks(SON) based on competitive Fuzzy Polynomial Neuron(FPN) for the optimal design of nonlinear process system. The SON architectures consist of layers with activation nodes based on fuzzy inference rules. Here each activation node is presented as FPN which includes either the simplified or regression Polynomial fuzzy inference rules. The proposed SON is a network resulting from the fusion of the Polynomial Neural Networks(PNN) and a fuzzy inference system. The conclusion part of the rules, especially the regression polynomial uses several types of high-order polynomials such as liner, quadratic and modified quadratic. As the premise part of the rules, both triangular and Gaussian-like membership functions are studied. Chaotic time series data used to evaluate the performance of our proposed model.

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