• Title/Summary/Keyword: optimal smoothing

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SMOOTHING APPROXIMATION TO l1 EXACT PENALTY FUNCTION FOR CONSTRAINED OPTIMIZATION PROBLEMS

  • BINH, NGUYEN THANH
    • Journal of applied mathematics & informatics
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    • v.33 no.3_4
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    • pp.387-399
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    • 2015
  • In this paper, a new smoothing approximation to the l1 exact penalty function for constrained optimization problems (COP) is presented. It is shown that an optimal solution to the smoothing penalty optimization problem is an approximate optimal solution to the original optimization problem. Based on the smoothing penalty function, an algorithm is presented to solve COP, with its convergence under some conditions proved. Numerical examples illustrate that this algorithm is efficient in solving COP.

Parameter estimation of mean field annealing technique for optimal boundary smoothing (최적의 Boundary Smoothing을 위한 Mean Field Annealing 기법의 파라미터 추정에 관한 연구)

  • Kwa
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.1
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    • pp.185-192
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    • 1997
  • We propose a method of paramete estimation using order-of-magnitude analysis for optimal boundary smoothing in Mean Field Annealing(MFA) technique in this paper. We previously proposed two boundary smoothing methods for consistent object representation in the previous paper, one is using a constratined regulaization(CR) method and the other is using a MFA method. The CR method causes unnecessary smoothing effects at corners. On the other hand, the MFA method method smooths our the noise without losing sharpness of corners. The MFA algorithm is influenced by several parameters such as standard deviation of the noise, the relativemagnitude of prior ter, initial temperature and final temperature. We propose a general parameter esimation method for optimal boundary smoothing using order-of-magnitude analysis to be used for consistent object representation in this paper. In addition, we prove the effectiveness of our parameter estimation and also show the temperature parameter sensitivities of the algorithm.

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Aggregated Smoothing: Considering All Streams Simultaneously for Transmission of Variable-Bit-Rate Encoded Video Objects

  • Kang, Sooyong;Yeom, Heon Y.
    • Journal of Communications and Networks
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    • v.5 no.3
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    • pp.258-265
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    • 2003
  • Transmission of continuous media streams has been a challenging problem of multimedia service. Lots of works have been done trying to figure out the best solution for this problem, and some works presented the optimal solution for transmitting the stored video using smoothing schemes applied to each individual stream. But those smoothing schemes considered only one stream, not the whole streams being serviced, to apply themselves, which could only achieve local optimum not the global optimum. Most of all, they did not exploit statistical multiplexing gain that can be obtained before smoothing. In this paper, we propose a new smoothing scheme that deals with not an individual stream but the whole streams being serviced simultaneously to achieve the optimal network bandwidth utilization and maximize the number of streams that can be serviced simultaneously. We formally proved that the proposed scheme not only provides deterministic QoS for each client but also maximizes number of clients that can be serviced simultaneously and hence achieves maximum utilization of transmission bandwidth.

Topology Optimization of a Vehicle's Hood Considering Static Stiffness (자동차 후드의 정강성을 고려한 위상 최적화)

  • Han, Seog-Young;Choi, Sang-Hyuk;Park, Jae-Yong;Hwang, Joon-Seong;Kim, Min-Sue
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.1
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    • pp.69-74
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    • 2007
  • Topology optimization of the inner reinforcement for a vehicle's hood has been performed by evolutionary structural optimization(ESO) using a smoothing scheme. The purpose of this study is to obtain optimal topology of the inner reinforcement for a vehicle's hood considering the static stiffness of bending and torsion simultaneously. To do this, the multiobjective optimization technique was implemented. Optimal topologies were obtained by the ESO method. From several combinations of weighting factors, a Pareto-optimal solution was obtained. Also, a smoothing scheme was implemented to suppress the checkerboard pattern in the procedure of topology optimization. It is concluded that ESO method with a smoothing scheme is effectively applied to topology optimization of the inner reinforcement of a vehicle's hood considering the static stiffness of bending and torsion.

Optimal Coefficient Selection of Exponential Smoothing Model in Short Term Load Forecasting on Weekdays (평일 단기전력수요 예측을 위한 최적의 지수평활화 모델 계수 선정)

  • Song, Kyung-Bin;Kwon, Oh-Sung;Park, Jeong-Do
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.2
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    • pp.149-154
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    • 2013
  • Short term load forecasting for electric power demand is essential for stable power system operation and efficient power market operation. High accuracy of the short term load forecasting can keep the power system more stable and save the power market operation cost. We propose an optimal coefficient selection method for exponential smoothing model in short term load forecasting on weekdays. In order to find the optimal coefficient of exponential smoothing model, load forecasting errors are minimized for actual electric load demand data of last three years. The proposed method are verified by case studies for last three years from 2009 to 2011. The results of case studies show that the average percentage errors of the proposed load forecasting method are improved comparing with errors of the previous methods.

On Practical Choice of Smoothing Parameter in Nonparametric Classification (베이즈 리스크를 이용한 커널형 분류에서 평활모수의 선택)

  • Kim, Rae-Sang;Kang, Kee-Hoon
    • Communications for Statistical Applications and Methods
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    • v.15 no.2
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    • pp.283-292
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    • 2008
  • Smoothing parameter or bandwidth plays a key role in nonparametric classification based on kernel density estimation. We consider choosing smoothing parameter in nonparametric classification, which optimize the Bayes risk. Hall and Kang (2005) clarified the theoretical properties of smoothing parameter in terms of minimizing Bayes risk and derived the optimal order of it. Bootstrap method was used in their exploring numerical properties. We compare cross-validation and bootstrap method numerically in terms of optimal order of bandwidth. Effects on misclassification rate are also examined. We confirm that bootstrap method is superior to cross-validation in both cases.

MULTI-OBJECTIVE OPTIMIZATION OF THE INNER REINFORCEMENT FOR A VEHICLE'S HOOD CONSIDERING STATIC STIFFNESS AND NATURAL FREQUENCY

  • Choi, S.H.;Kim, S.R.;Park, J.Y.;Han, S.Y.
    • International Journal of Automotive Technology
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    • v.8 no.3
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    • pp.337-342
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    • 2007
  • A multi-objective optimization technique was implemented to obtain optimal topologies of the inner reinforcement for a vehicle's hood simultaneously considering the static stiffness of bending and torsion and natural frequency. In addition, a smoothing scheme was used to suppress the checkerboard patterns in the ESO method. Two models with different curvature were chosen in order to investigate the effect of curvature on the static stiffness and natural frequency of the inner reinforcement. A scale factor was employed to properly reflect the effect of each objective function. From several combinations of weighting factors, a Pareto-optimal topology solution was obtained. As the weighting factor for the elastic strain efficiency went from 1 to 0, the optimal topologies transmitted from the optimal topology of a static stiffness problem to that of a natural frequency problem. It was also found that the higher curvature model had a larger static stiffness and natural frequency than the lower curvature model. From the results, it is concluded that the ESO method with a smoothing scheme was effectively applied to topology optimization of the inner reinforcement of a vehicle's hood.

The Family Approach to Nonparametric Estimation of the Regression Function (비모수적 회귀함수 추정에 대한 Family Approach)

  • 정성석
    • Journal of Korean Society for Quality Management
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    • v.25 no.4
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    • pp.106-114
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    • 1997
  • The smoothing parameter or bandwidth is crucial to performance of the kernel based regression estimator. So the choice of a "optimal" smoothing parameter produce a single curve estimate. If a single estimate is replaced by a family of estimates, it become easy that we understand what varies with choice of the smoothing parameter. This paper suggests the threshold of the maximum bandwidth and the number of the family members in the regression context.n context.

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A Note on Smoothing Distribution Function Estimation

  • Chu, In-Sun;Choi, Jae-Ryong
    • Communications for Statistical Applications and Methods
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    • v.4 no.3
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    • pp.911-915
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    • 1997
  • The purpose of this paper is to consider the problem of selection of optimal smoothing parameter for kernel-type distribution function estimator, which asymptotically minimizes mean Hellinger distance.

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Path-smoothing for a robot arm manipulator using a Gaussian process

  • Park, So-Youn;Lee, Ju-Jang
    • Journal of the Korean Society of Industry Convergence
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    • v.18 no.4
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    • pp.191-196
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    • 2015
  • In this paper, we present a path-smoothing algorithm for a robot arm manipulator that finds the path using a joint space-based rapidly-exploring random tree. Unlike other smoothing algorithms which require complex mathematical computation, the proposed path-smoothing algorithm is done using a Gaussian process. To find the optimal hyperparameters of the Gaussian process, we use differential evolution hybridized with opposition-based learning. The simulation result indicates that the Gaussian process whose hyperparameters were optimized by hybrid differential evolution successfully smoothed the path generated by the joint space-based rapidly-exploring random tree.