• Title/Summary/Keyword: input parameter

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Kernel Poisson regression for mixed input variables

  • Shim, Jooyong
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.6
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    • pp.1231-1239
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    • 2012
  • An estimating procedure is introduced for kernel Poisson regression when the input variables consist of numerical and categorical variables, which is based on the penalized negative log-likelihood and the component-wise product of two different types of kernel functions. The proposed procedure provides the estimates of the mean function of the response variables, where the canonical parameter is linearly and/or nonlinearly related to the input variables. Experimental results are then presented which indicate the performance of the proposed kernel Poisson regression.

Neuro-Fuzzy System and Its Application by Input Space Partition Methods (입력 공간 분할에 따른 뉴로-퍼지 시스템과 응용)

  • 곽근창;유정웅
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.10a
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    • pp.433-439
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    • 1998
  • In this paper, we present an approach to the structure identification based on the input space partition methods and to the parameter identification by hybrid learning method in neuro-fuzzy system. The structure identification can automatically estimate the number of membership function and fuzzy rule using grid partition, tree partition, scatter partition from numerical input-output data. And then the parameter identification is carried out by the hybrid learning scheme using back-propagation and least squares estimate. Finally, we sill show its usefulness for neuro-fuzzy modeling to truck backer-upper control.

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On the Local Identifiability of Load Model Parameters in Measurement-based Approach

  • Choi, Byoung-Kon;Chiang, Hsiao-Dong
    • Journal of Electrical Engineering and Technology
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    • v.4 no.2
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    • pp.149-158
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    • 2009
  • It is important to derive reliable parameter values in the measurement-based load model development of electric power systems. However parameter estimation tasks, in practice, often face the parameter identifiability issue; whether or not the model parameters can be estimated with a given input-output data set in reliable manner. This paper introduces concepts and practical definitions of the local identifiability of model parameters. A posteriori local identifiability is defined in the sense of nonlinear least squares. As numerical examples, local identifiability of third-order induction motor (IM) model and a Z-induction motor (Z-IM) model is studied. It is shown that parameter ill-conditioning can significantly affect on reliable parameter estimation task. Numerical studies show that local identifiability can be quite sensitive to input data and a given local solution. Finally, several countermeasures are proposed to overcome ill-conditioning problem in measurement-based load modeling.

The characteristics of bead welding on steel with process parameter during the laser-arc hybrid welding(II) - Effect of heat input parameters - (강의 레이저-아크 하이브리드 용접시 공정변수에 따른 비드용접특성 (II) - 용접 입열 변수의 영향 -)

  • Kim, Jond-Do;Myung, Gi-Hoon;Park, In-Duck
    • Journal of Welding and Joining
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    • v.33 no.2
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    • pp.91-96
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    • 2015
  • The laser-arc hybrid welding of SS400 steel was carried out with the use of disk laser equipment of 6.6kW maximum power and MAG equipment of pulse mode. Parameter regarding heat input is one of the most important factors that directly affect penetration characteristics and welding defect. Therefore in this study, the effects of laser power, welding speed and current, voltage and pulse correction were investigated. As experiment result, it was found that the lower heat input, the more likely humping bead is formed at the back, and such humping bead could be suppressed by increasing laser power and arc current or decreasing welding speed, thus increasing heat input. Also deep penetration could be achieved by reducing arc voltage or pulse correction parameter in the same welding condition.

A Study on Dual Response Approach Combining Neural Network and Genetic Algorithm (인공신경망과 유전알고리즘 기반의 쌍대반응표면분석에 관한 연구)

  • Arungpadang, Tritiya R.;Kim, Young Jin
    • Journal of Korean Institute of Industrial Engineers
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    • v.39 no.5
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    • pp.361-366
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    • 2013
  • Prediction of process parameters is very important in parameter design. If predictions are fairly accurate, the quality improvement process will be useful to save time and reduce cost. The concept of dual response approach based on response surface methodology has widely been investigated. Dual response approach may take advantages of optimization modeling for finding optimum setting of input factor by separately modeling mean and variance responses. This study proposes an alternative dual response approach based on machine learning techniques instead of statistical analysis tools. A hybrid neural network-genetic algorithm has been proposed for the purpose of parameter design. A neural network is first constructed to model the relationship between responses and input factors. Mean and variance responses correspond to output nodes while input factors are used for input nodes. Using empirical process data, process parameters can be predicted without performing real experimentations. A genetic algorithm is then applied to find the optimum settings of input factors, where the neural network is used to evaluate the mean and variance response. A drug formulation example from pharmaceutical industry has been studied to demonstrate the procedures and applicability of the proposed approach.

The pattern cognition and classification used neural network

  • Son, Jun-Hyug;Seo, Bo-Hyeok
    • Proceedings of the KIEE Conference
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    • 2004.07d
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    • pp.2525-2527
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    • 2004
  • This paper classify using Adaptive Resonance Theory 1(ART1) as a vigilance parameter of pattern clustering algorithm. Inherent characteristics of the model are analyzed. In particular the vigilance parameter $\rho$ and its role in classification of patterns is examined. Our estimates show that the vigilance parameter as designed originally does not necessarily increase the number of categories with its value but can decrease also. This is against the claim of solving the stability-plasticity dilemma. However, we have proposed a modified vigilance parameter setting criterion which takes into account the problem of subset and superset patterns and stably categorizes arbitrarily many input patterns in one list presentation when the vigilance parameter is closer to one. And this paper goal is the input pattern cognition and classification using neural network.

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Control and Parameter Estimation of Uncertain Robotic Systems by An Iterative Learning Method (불확실한 로보트 시스템의 제어와 파라미터 추정을 위한 반복학습제어)

  • 국태용;이진수
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.40 no.4
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    • pp.427-438
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    • 1991
  • An iterative learning control scheme for exact-tracking control and parameter estimation of uncertain robotic system is preented. In the learning control structure, the control input converges globally and asymtotically to the desired input as iteration increases. Since convergence of parameter errors depends only on the persistent exciting condition of system trajectories along the iteration independently of the time-duration of trajectories, it may be achieved with system trajectories with small duration. In addition, the proposd learning control schemes are applicable to time-varying parametric systems as well as time-invariant systems, because the parameter estimation is performed at each fixed time along the iteration. In the parameter estimator, the acceleration information as well as the inversion of estimated inertia matrix are not used at all, which makes the proposed learning control schemes more feasible.

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Generation of 3D STEP Model from 2D Drawings Using Feature Definition of Ship Structure (선체구조 특징형상 정의에 의한 2D 도면에서 3D STEP 선체 모델의 생성)

  • 황호진;한순흥;김용대
    • Korean Journal of Computational Design and Engineering
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    • v.8 no.2
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    • pp.122-132
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    • 2003
  • STEP AP218 has a standard schema to represent the structural model of a midship section. While it helps to exchange ship structural models among heterogeneous automation systems, most shipyards and classification societies still exchange information using 2D paper drawings. We propose a feature parameter input method to generate a 3D STEP model of a ship structure from 2D drawings. We have analyzed the ship structure information contained in 2D drawings and have defined a data model to express the contents of the drawing. We also developed a QUI for the feature parameter input. To translate 2D information extracted from the drawing into a STEP AP2l8 model, we have developed a shape generation library, and generated the 3D ship model through this library. The generated 3D STEP model of a ship structure can be used to exchange information between design departments in a shipyard as well as between classification societies and shipyards.

Design of the optimal inputs for parameter estimation in linear dynamic systems (선형계통의 파라미터 추정을 위한 최적 입력의 설계)

  • 양흥석;이석원;정찬수
    • 제어로봇시스템학회:학술대회논문집
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    • 1986.10a
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    • pp.73-77
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    • 1986
  • Optimal input design problem for linear regression model with constrained output variance has been considered. It is shown that the optimal input signal for the linear regression model can also be realized as an ARMA process. Monte-Carlo simulation results show that the optimal stochastic input leads to comparatively better estimation accuracy than white input signal.

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Development and performance evaluation of a test particle generator for a field inspection equipment of PM-2.5 sensors (미세먼지 간이측정기 현장 검사용 시험 입자 발생기 개발 및 성능 평가)

  • Chung, Hyeok;Park, Jin-Soo
    • Particle and aerosol research
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    • v.18 no.3
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    • pp.61-68
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    • 2022
  • In this study, a fluidized bed particle generator was developed to generate an aerosol without supply of compressed air and to increase portability. It was assumed that the mixing ratio of the test particles and beads, the input amount, and the air flow rate supplied to the generator would have effect on the aerosol generation characteristics. The product of these three parameters was set as a characteristic parameter and particle generation characteristics according to the change of the characteristic parameter were observed. As a result, it was confirmed that the input amount of test particles and beads was not suitable as a characteristic parameter and a characteristic parameter expressed as a product of the mass mixing ratio and the air flowrate was newly defined. When the new characteristic parameter is applied, it can be confirmed that the total amount of particles generated from the particle generator is a function of the characteristic parameter. As a result of measuring the amount of particle generation by adjusting the characteristic parameter, it was confirmed that the performance required for the test particle generator for the field inspection equipment of PM-2.5 sensors could be satisfied.