• 제목/요약/키워드: polynomial functions

검색결과 450건 처리시간 0.025초

Information Granulation-based Fuzzy Inference Systems by Means of Genetic Optimization and Polynomial Fuzzy Inference Method

  • Park Keon-Jun;Lee Young-Il;Oh Sung-Kwun
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • 제5권3호
    • /
    • pp.253-258
    • /
    • 2005
  • In this study, we introduce a new category of fuzzy inference systems based on information granulation to carry out the model identification of complex and nonlinear systems. Informal speaking, information granules are viewed as linked collections of objects (data, in particular) drawn together by the criteria of proximity, similarity, or functionality. To identify the structure of fuzzy rules we use genetic algorithms (GAs). Granulation of information with the aid of Hard C-Means (HCM) clustering algorithm help determine the initial parameters of fuzzy model such as the initial apexes of the membership functions and the initial values of polynomial functions being used in the premise and consequence part of the fuzzy rules. And the initial parameters are tuned effectively with the aid of the genetic algorithms and the least square method (LSM). The proposed model is contrasted with the performance of the conventional fuzzy models in the literature.

x2+ax+c를 이용한 수열 생성 방법의 특성화 (Characteristic of Method of generation sequence using x2+ax+c)

  • 조성진;황윤희;최언숙;허성훈;김진경
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2009년도 춘계학술대회
    • /
    • pp.433-436
    • /
    • 2009
  • 최대 주기를 갖는 의사 난수열을 생성하기 위하여 다양한 방법들이 시도되어 왔다. 가장 일반적인 방법은 원시다항식을 특성다항식으로 갖는 LFSR을 생성기로 이용하는 방법, LFSR보다 랜덤성이 우수한 셀룰라 오토마타를 생성기로 이용하는 방법과 이차함수를 이용하여 최대 주기 수열을 생성하는 방법이 있다. 본 논문에서는 보다 긴 주기를 갖는 수열을 생성하기 위하여 이차함수를 이용한 수열 생성 방법에 관하여 분석하고 특성화한다.

  • PDF

Design of $H_{\infty}$ Controller with Different Weighting Functions Using Convex Combination

  • Kim Min-Chan;Park Seung-Kyu;Kwak Gun-Pyong
    • Journal of information and communication convergence engineering
    • /
    • 제2권3호
    • /
    • pp.193-197
    • /
    • 2004
  • In this paper, a combination problem of controllers which are the same type of $H_{\infty}$ controllers designed with different weighting functions. This approach can remove the difficulty in the selection of the weighting functions. As a sub-controller, the Youla type of $H_{\infty}$ controller is used. In the $H_{\infty}$ controller, Youla parameterization is used to minimize $H_{\infty}$ norm of mixed sensitivity function by using polynomial approach. Computer simulation results show the robustness improvement and the performance improvement.

COEFFICIENT ESTIMATES FOR GENERALIZED LIBERA TYPE BI-CLOSE-TO-CONVEX FUNCTIONS

  • Serap, Bulut
    • Korean Journal of Mathematics
    • /
    • 제30권4호
    • /
    • pp.629-642
    • /
    • 2022
  • In a recent paper, Sakar and Güney introduced a new class of bi-close-to-convex functions and determined the estimates for the general Taylor-Maclaurin coefficients of functions therein. The main purpose of this note is to give a generalization of this class. Also we point out the proof by Sakar and Güney is incorrect and present a correct proof.

KRULL DIMENSION OF HURWITZ POLYNOMIAL RINGS OVER PRÜFER DOMAINS

  • Le, Thi Ngoc Giau;Phan, Thanh Toan
    • 대한수학회보
    • /
    • 제55권2호
    • /
    • pp.625-631
    • /
    • 2018
  • Let R be a commutative ring with identity and let R[x] be the collection of polynomials with coefficients in R. There are a lot of multiplications in R[x] such that together with the usual addition, R[x] becomes a ring that contains R as a subring. These multiplications are from a class of functions ${\lambda}$ from ${\mathbb{N}}_0$ to ${\mathbb{N}}$. The trivial case when ${\lambda}(i)=1$ for all i gives the usual polynomial ring. Among nontrivial cases, there is an important one, namely, the case when ${\lambda}(i)=i!$ for all i. For this case, it gives the well-known Hurwitz polynomial ring $R_H[x]$. In this paper, we completely determine the Krull dimension of $R_H[x]$ when R is a $Pr{\ddot{u}}fer$ domain. Let R be a $Pr{\ddot{u}}fer$ domain. We show that dim $R_H[x]={\dim}\;R+1$ if R has characteristic zero and dim $R_H[x]={\dim}\;R$ otherwise.

Evolutionary Optimized Fuzzy Set-based Polynomial Neural Networks Based on Classified Information Granules

  • Oh, Sung-Kwun;Roh, Seok-Beom;Ahn, Tae-Chon
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
    • /
    • pp.2888-2890
    • /
    • 2005
  • In this paper, we introduce a new structure of fuzzy-neural networks Fuzzy Set-based Polynomial Neural Networks (FSPNN). The two underlying design mechanisms of such networks involve genetic optimization and information granulation. The resulting constructs are Fuzzy Polynomial Neural Networks (FPNN) with fuzzy set-based polynomial neurons (FSPNs) regarded as their generic processing elements. First, we introduce a comprehensive design methodology (viz. a genetic optimization using Genetic Algorithms) to determine the optimal structure of the FSPNNs. This methodology hinges on the extended Group Method of Data Handling (GMDH) and fuzzy set-based rules. It concerns FSPNN-related parameters such as the number of input variables, the order of the polynomial, the number of membership functions, and a collection of a specific subset of input variables realized through the mechanism of genetic optimization. Second, the fuzzy rules used in the networks exploit the notion of information granules defined over systems variables and formed through the process of information granulation. This granulation is realized with the aid of the hard C- Means clustering (HCM). The performance of the network is quantified through experimentation in which we use a number of modeling benchmarks already experimented with in the realm of fuzzy or neurofuzzy modeling.

  • PDF

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

  • 박병준;오성권;김현기
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
    • /
    • pp.372-372
    • /
    • 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.

  • PDF

A High Image Compression for Computer Storage and Communication

  • 장종환
    • 자연과학논문집
    • /
    • 제4권
    • /
    • pp.191-220
    • /
    • 1991
  • Human Visual System(HVS)의 특성과 image의 textural regions의 roughness을 이용하여 image segmentation을 행하여 high compression에서도 고화질을 나타내는 새로운 image coder를 이 논문에서 논한다. 제안된 image coder는 constant segments를 가진 segmentation-based image coding technique의 문제들을 다음과 같은 방법론을 제안함으로써 해결하였다. Image를 HVS으로 보았을 때 degree of roughness에 관하여 textually homogeneous regions으로 segmentation하였다. Fractal dimension을 roughness of textural regions을 측정하기 위하여 사용하였다. Segmentation은 fractal dimension을 thresholding하여 textural regions이 three texture classes로 분류하였다(perceived constant intensity, smooth texture, and rough texture). High compression을 가지는 고질화의 image coder는 각각의 segment boundary와 각각의 texture class에 효율적인 coding technique를 적용 함으로 얻었다.

  • PDF

데이터 정보입자 기반 퍼지 추론 시스템의 최적화 (Optimization of Fuzzy Inference Systems Based on Data Information Granulation)

  • 오성권;박건준;이동윤
    • 대한전기학회논문지:시스템및제어부문D
    • /
    • 제53권6호
    • /
    • pp.415-424
    • /
    • 2004
  • In this paper, we introduce and investigate a new category of rule-based fuzzy inference system based on Information Granulation(IG). The proposed rule-based fuzzy modeling implements system structure and parameter identification in the efficient form of “If..., then...” statements, and exploits the theory of system optimization and fuzzy implication rules. The form of the fuzzy rules comes with three types of fuzzy inferences: a simplified one that involves conclusions that are fixed numeric values, a linear one where the conclusion part is viewed as a linear function of inputs, and a regression polynomial one as the extended type of the linear one. By the nature of the rule-based fuzzy systems, these fuzzy models are geared toward capturing relationships between information granules. The form of the information granules themselves becomes an important design features of the fuzzy model. Information granulation with the aid of HCM(Hard C-Means) clustering algorithm hell)s determine the initial parameters of rule-based fuzzy model such as the initial apexes of the membership functions and the initial values of polynomial function being used in the Premise and consequence Part of the fuzzy rules. And then the initial Parameters are tuned (adjusted) effectively with the aid of the improved complex method(ICM) and the standard least square method(LSM). In the sequel, the ICM and LSM lead to fine-tuning of the parameters of premise membership functions and consequent polynomial functions in the rules of fuzzy model. An aggregate objective function with a weighting factor is proposed in order to achieve a balance between performance of the fuzzy model. Numerical examples are included to evaluate the performance of the proposed model. They are also contrasted with the performance of the fuzzy models existing in the literature.