• 제목/요약/키워드: Structure and function

검색결과 6,626건 처리시간 0.041초

비선형, 비정상 시계열 예측을 위한 RBF(Radial Basis Function) 회로망 구조 (RBF Network Structure for Prediction of Non-linear, Non-stationary Time Series)

  • 김상환;이종호
    • 대한전기학회논문지:전력기술부문A
    • /
    • 제48권2호
    • /
    • pp.168-175
    • /
    • 1999
  • In this paper, a modified RBF(Radial Basis Function) network structure is suggested for the prediction of a time-series with non-linear, non-stationary characteristics. Coventional RBF network predicting time series by using past outputs sense the trajectory of the time series and react when there exists strong relation between input and hidden activation function's RBF center. But this response is highly sensitive to level and trend of time serieses. In order to overcome such dependencies, hidden activation functions are modified to react to the increments of input variable and multiplied by increment(or dectement) for prediction. When the suggested structure is applied to prediction of Macyey-Glass chaotic time series, Lorenz equation, and Rossler equation, improved performances are obtained.

  • PDF

비 측정 상태변수를 갖는 위상 표준형계통에 대한 가변구조 제어기의 설계 (The Design of Variable Structure Controller for the System in Phase Canonical Form with Incomplete State Measurements)

  • 박귀태;최중경
    • 대한전기학회논문지
    • /
    • 제41권8호
    • /
    • pp.902-913
    • /
    • 1992
  • There have been several control schemes for the single input systems with unmeasurable state variables using variable structure control(VSC) theory. In the previous VSC, the systems must be represented in phase canonical form and the complete measurements for each state variable must be assumed. In order to eliminate these restrictions several VSC methods were proposed. And especially for the systems in phase canonical form with unmeasurable state variables, the reduced order switching function algorithm was proposed. But this method has many drawbacks and can not be used in the case of general form (not phase canonical form) dynamic system. Therefore this paper propose new construction method of switching fuction for the systems in phase canonical form, which reduce the restriction of reduced order switching function algorithm. And this algorithm can be realized for any state representation and adopted in the systems where not all states are available for switching function synthesis or control.

  • PDF

모듈화된 웨이블렛 신경망의 적응 구조 (Adaptive Structure of Modular Wavelet Neural Network)

  • 서재용;김용택;김성현;조현찬;전홍태
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
    • /
    • pp.247-250
    • /
    • 2001
  • In this paper, we propose an growing and pruning algorithm to design the adaptive structure of modular wavelet neural network(MWNN) with F-projection and geometric growing criterion. Geometric growing criterion consists of estimated error criterion considering local error and angle criterion which attempts to assign wavelet function that is nearly orthogonal to all other existing wavelet functions. These criteria provide a methodology that a network designer can constructs wavelet neural network according to one's intention. The proposed growing algorithm grows the module and the size of modules. Also, the pruning algorithm eliminates unnecessary node of module or module from constructed MWNN to overcome the problem due to localized characteristic of wavelet neural network which is used to modules of MWNN. We apply the proposed constructing algorithm of the adaptive structure of MWNN to approximation problems of 1-D function and 2-D function, and evaluate the effectiveness of the proposed algorithm.

  • PDF

The Regulatory Domain of Troponin C: To Be Flexible or Not To Be Flexible

  • Gagne, Stephane M.;Sykes, Michael T.;Sykes, Brain D.
    • 한국자기공명학회논문지
    • /
    • 제2권2호
    • /
    • pp.131-140
    • /
    • 1998
  • The calcium-induced structural changes in the skeletal muscle regulatory protein troponin C (NTnC) involve a transition from a ‘closed’to an ‘open’structure with the concomitant exposure of a large hydrophobic interaction site for target proteins. Structural studies have served to define this conformational change and elucidate the mechanism of the linkage between calcium binding and the induced structural changes. There are now several structures of NTnC available from both NMR and X-ray crystallography. Comparison of the calcium bound structures reveals differences in the level of opening. We have considered the concept of a flexible open state of NTnC as a possible explanation for this apparent discrepancy. We also present simulations of the closed-to-open transition which are in agreement with the flexibility concept and with experimental energetics data.

  • PDF

모형의 복잡성, 구조 및 목적함수가 모형 검정에 미치는 영향 (Effects of Model Complexity, Structure and Objective Function on Calibration Process)

  • Choi, Kyung Sook
    • 한국농공학회지
    • /
    • 제45권4호
    • /
    • pp.89-97
    • /
    • 2003
  • Using inference models developed for estimation of the parameters necessary to implement the Runoff Block of the Stormwater Management Model (SWMM), a number of alternative inference scenarios were developed to assess the influence of inference model complexity and structure on the calibration of the catchment modelling system. These inference models varied from the assumption of a spatially invariant value (catchment average) to spatially variable with each subcatchment having its own unique values. Fur-thermore, the influence of different measures of deviation between the recorded information and simulation predictions were considered. The results of these investigations indicate that the model performance is more influenced by model structure than complexity, and control parameter values are very much dependent on objective function selected as this factor was the most influential for both the initial estimates and the final results.

Optimization for the Initial Designed Structure by Localization Using Genetic Algorithm

  • Kim, Seong-Joo;Kim, Yong-Taek;Ko, Jae-Yang;Jeon, Hong-Tae
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2002년도 ITC-CSCC -3
    • /
    • pp.1650-1653
    • /
    • 2002
  • In this paper, we propose the initial optimized structure of the Radial Basis function Networks that is simple in the part of the structure and fast converges more than neural networks with the analysis method using Time- Frequency Localization. We construct the hidden node with the Radial Basis functions their localization are similar with approximation target function in the plane of the Time and Frequency. We finally make a good decision of the initial structure for function approximation using genetic algorithm

  • PDF

디지털 실험장치를 이용한 판의 모우드 해석 (Model Analysis of Plate using by Digital Test System)

  • 홍봉기;배동명;배성용
    • 수산해양기술연구
    • /
    • 제29권1호
    • /
    • pp.39-55
    • /
    • 1993
  • Modal Analysis is the process of characterizing the dynamic properties of an elastic structure by identifying its modes of vibration. A mode of vibration is a global property of an elastic structure. That is, a mode has a specific natural frequency and damping factor which can be identified from response data at practically any point on a structure, and it has a characteristic mode shape which identifies the mode spatially over the entire structure. Modal testing is able to be performed on structural and mechanical structure in an effort to learn more about their elastic behavior. Once the dynamic properties of a structure are known its behavior can be predicted and therefore controlled or corrected. Resonant frequencies, damping factors and mode shape data can be used directly by a mechanical designer to pin point weak spots in a structure design, or this data can also be used to confirm or synthesize equations of motion for the elastic structure. These differential equations can be used to simulate structural response to know input forces and to examine the effects of pertubations in the distributed mass, stiffness and damping properties of the structure in more detail. In this paper the measurement of transfer functions in digital form, and the application of digital parameter identification techniques to identify modal parameters from the measured transfer function data are discussed. It is first shown that the transfer matrix, which is a complete dynamic model of an elastic plate structure can be written in terms of the structural modes of vibration. This special mathematical form allows one to identify the complete dynamics of the structure from a much reduced set of test data, and is the essence of the modal approach to identifying the dynamics of a structure. Finally, the application of transfer function models and identification techniques for obtaining modal parameters from the transfer function data are discussed. Characteristics on vibration response of elastic plate structure obtained from the dynamic analysis by Finite Element Method are compared with results of modal analysis.

  • PDF

뉴런의 기능을 모사한 3×3배열구조의 디지털 회로에서의 오류위치 확인 및 복구 알고리즘 (An Error position detection and recovery algorithm at 3×3 matrix digital circuit by mimicking a Neuron)

  • 김석환;허창우
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2016년도 추계학술대회
    • /
    • pp.101-104
    • /
    • 2016
  • 본 연구에서는 뉴런이 지니는 기능 및 결합구조를 모사하여 3x3 배열의 기능별로 분리시킨 후 디지털회로에서 동작 중 발생할 수 있는 일시적 또는 영구적인 오류 위치를 정확히 찾아내어 복구 시키는 알고리즘을 제안한다. 결합된 세포에서 어느 특정 일부분이 문제가 발생할 경우 그 기능을 다른 세포로 분화되어 동일 기능을 수행하며 오류가 발생한 세포는 주변 세포에 의해 사멸시키는 단계를 거친다. 이런 세포가 지니는 기능 및 구조를 디지털 회로내부에 기능 블록구조로 설계하여 알고리즘을 제안한다.

  • PDF

NON-DEVELOPABLE RULED SURFACES WITH TIMELIKE RULING IN MINKOWSKI 3-SPACE

  • YANG, YUN;YU, YANHUA
    • 대한수학회보
    • /
    • 제52권4호
    • /
    • pp.1339-1351
    • /
    • 2015
  • In this paper, using pseudo-spherical Frenet frame of pseudo-spherical curves in hyperbolic space, we define the notion of the structure functions on the non-developable ruled surfaces with timelike ruling. Then we obtain the properties of the structure functions and a complete classification of the non-developable ruled surfaces with timelike ruling in Minkowski 3-space by the theories of the structure functions.

유전 알고리즘과 시간-주파수 지역화를 이용한 방사 기준 함수망의 초기 최적화 (Initial Optimization of the RBFN with Time-Frequency Localization Using Genetic Algorithm)

  • 김성주;서재용;김용택;조현찬;전홍태
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
    • /
    • pp.221-224
    • /
    • 2001
  • In this paper, we propose the initial optimized structure of the Radial Basis Function Network which is more simple in the part on the structure and converges more faster than Neural Network with the analysis method using Time-Frequency Localization and genetic algorithm. When we construct the hidden node with the Radial Basis Function whose localization is similar with an approximation target function in the plane of the Time and Frequency, we have initial structure of RBFN, After that, we evaluate the parameters of RBF in the network and the parameters needed for the network is more a few. Finally, we make a good decision of the initial structure having an ability of approximation.

  • PDF