• Title/Summary/Keyword: approximation model

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A Study on 2-D Occluded Objects Recognition and Hidden Edge Reconstruction Using Polygonal Approximation and Coordinates Transition (다각근사화와 좌표 이동을 이용한 겹친 2차원 물체 인식 및 은선 재구성)

  • 박원진;유광열;이대영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.12 no.5
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    • pp.415-427
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    • 1987
  • This paper presents an experimental model-based vision system which can identify and locate objects in scenes containing multiple occluded parts. The objects are assumed to be rigid and planar parts. In any recognition system the-type of objects that might appear in the image dictates the type of knowledge that is needed to recognize the object. The data is reduced to a sequential list of points or pixels that appear on the boundary of the objects. Next the boundary of the objects is smoothed using a polygonal approximation algorithm. Recognition cosists in finding the prototype that matches model to image. Now the hidden edge is reconstructed by transition model objects into occluded objects. The best match is obtained by optimising some similarity measure.

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Advanced Polynomial Neural Networks Architecture with New Adaptive Nodes

  • Oh, Sung-Kwun;Kim, Dong-Won;Park, Byoung-Jun;Hwang, Hyung-Soo
    • Transactions on Control, Automation and Systems Engineering
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    • v.3 no.1
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    • pp.43-50
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    • 2001
  • In this paper, we propose the design procedure of advance Polynomial Neural Networks(PNN) architecture for optimal model identification of complex and nonlinear system. The proposed PNN architecture is presented as the generic and advanced type. The essence of the design procedure dwells on the Group Method of Data Handling(GMDH). PNN is a flexible neural architecture whose structure is developed through learning. In particular, the number of layers of the PNN is not fixed in advance but is generated in a dynamic way. In this sense, PNN is a self-organizing network. With the aid of three representative numerical examples, compari-sons show that the proposed advanced PNN algorithm can produce the model with higher accuracy than previous other works. And performance index related to approximation and generalization capabilities of model is evaluated and also discussed.

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An Analysis of the 1/f Noise Characteristics of Pocket Implanted MOSFETS (포켓 이온 주입된 MOSFET소자의 1/f 잡음 특성)

  • 이병헌;이기영
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.3
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    • pp.1-8
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    • 2004
  • The anomalous behavior of the 1/f noise of halo or pocket ion implanted MOSFETs is investigated. The model for the anomalous 1/f noise behaviors of MOSFETs, which consist of inhomogeneous conductance along the channel is improved within a regional approximation as previous works and presented in a fen directly applicable to halo MOSFETs. The presented model reduces to the previous results, discussed in the linear region operation, for small drain bias. Comparisons with experimental results show that the 1/f model based on the regional approach can be applicable for limited ranges, especially for sufficiently large gate bias voltages.

Sparse Matrix Computation in Mixed Effects Model (희소행렬 계산과 혼합모형의 추론)

  • Son, Won;Park, Yong-Tae;Kim, Yu Kyeong;Lim, Johan
    • The Korean Journal of Applied Statistics
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    • v.28 no.2
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    • pp.281-288
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    • 2015
  • In this paper, we study an approximate procedure to evaluate a penalized maximum likelihood estimator (MLE) for a mixed effects model. The procedure approximates the Hessian matrix of the penalized MLE with a structured sparse matrix or an arrowhead type matrix to speed its computation. In this paper, we numerically investigate the gain in computation time as well as approximation error from the considered approximation procedure.

A Theory on Phase Behaviors of Diblock Copolymer/Homopolymer Blends

  • 윤경섭;박형석
    • Bulletin of the Korean Chemical Society
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    • v.16 no.9
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    • pp.873-885
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    • 1995
  • The local structural and thermodynamical properties of blends A-B/H of a diblock copolymer A-B and a homopolymer H are studied using the polymer reference interaction site model (RISM) integral equation theory with the mean-spherical approximation closure. The random phase approximation (RPA)-like static scattering function is derived and the interaction parameter is obtained to investigate the phase transition behaviors in A-B/H blends effectively. The dependences of the microscopic interaction parameter and the macrophase-microphase separation on temperature, molecular weight, block composition and segment size ratio of the diblock copolymer, density, and concentration of the added homopolymer, are investigated numerically within the framework of Gaussian chain statistics. The numerical calculations of site-site interchain pair correlation functions are performed to see the local structures for the model blends. The calculated phase diagrams for A-B/H blends from the polymer RISM theory are compared with results by the RPA model and transmission electron microscopy (TEM). Our extended formal version shows the different feature from RPA in the microscopic phase separation behavior, but shows the consistency with TEM qualitatively. Scaling relationships of scattering peak, interaction parameter, and temperature at the microphase separation are obtained for the molecular weight of diblock copolymer. They are compared with the recent data by small-angle neutron scattering measurements.

A Study on Application of Reverse Engineering for Technical Surfaces (기능성곡면의 역공학 적용에 관한 연구)

  • 황종대;정종윤;정윤교
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.319-325
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    • 2002
  • Reverse Engineering is to find CAD model through measured data of a physical model which is not available in CAD model. The measured data are obtained from measuring with Coordinate Measuring Machine or Laser Scanner. This paper introduces efficient methods of reconstruction through the applicating process of the Reverse Engineering with technical surfaces.

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Nonlinear Control of General System based on a Model with Coefficients of State-Depended Representation

  • Nakamura, Masatoshi;Zhang, Tao
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.76.1-76
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    • 2002
  • This paper addresses a method for nonlinear controller construction for a general nonlinear system with the separation of controller construction and manipulated values generation. The nonlinear system model is firstly expressed with the coefficients of state-depended representation. The nonlinear control is designed without any approximation based on the model with state-depended representation. At the stage of controller implementation for the nonlinear system, the manipulated values are calculated accurately by use of an algorithm of the numerical analysis. The numerical error for calculating the manipulated value can be reduced to zero by selecting the sampling interval being a small val...

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CMBR FLUCTUATIONS IN THE BIANCHI TYPE I SPACETIME: THE EFFECTS OF GRAVITATIONAL WAVES (비앙키 I 형 시공간 속의 CMBR 흔들림: 중력파의 영향)

  • Song, D.J.
    • Publications of The Korean Astronomical Society
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    • v.18 no.1
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    • pp.1-9
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    • 2003
  • In the framework of linear perturbation theory and linear approximation of spacetime anisotropy, we investigated the formulae for the CMBR temperature anisotropy and fluctuation spectrum which have their origin in the primordial tensor perturbations of the perturbed Bianchi type I universe model. The resulting formulae were compared with those of the flat Friedmann model.

Frequency-Domain Balanced Stochastic Truncation for Continuous and Discrete Time Systems

  • Shaker, Hamid Reza
    • International Journal of Control, Automation, and Systems
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    • v.6 no.2
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    • pp.180-185
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    • 2008
  • A new method for relative error continuous and discrete time model order reduction is proposed. The reduction technique is based on two recently developed methods, namely frequency domain balanced truncation within a frequency bound and inner-outer factorization techniques. The proposed method is of interest for practical model order reduction because in this context it shows to keep the accuracy of the approximation as high as possible without sacrificing the computational efficiency. Numerical results show the accuracy and efficiency enhancement of the method.

Discrete model reduction over disc-type analytic domains (디스크형태의 해석적영역을 가지는 이산모델 차수축소)

  • 오도창;정은태;이갑래;박홍배
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.5
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    • pp.27-34
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    • 1998
  • This paper is on the discrete model reduction method over disc-type analytic domains. We define hankel singular value over the disc that is mapped by standard bilinear mapping. And the generalized singular perturbation approximation and the direct truncation are generalized to GSPA and DT over a disc. Furthermore, it is shown that the reduced order model over a smaller domaing has a smaller .inf.-norm error bound. And the poposed reduction method is used to obtain the regional pole placement property.

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