• Title/Summary/Keyword: Quadratic Loss

Search Result 118, Processing Time 0.026 seconds

A Double Cantilever Sandwich Beam Method far Evaluating Frequency Dependence of Dynamic Modulus and Damping Factor of Rubber Materials (고무의 동탄성계수와 손실계수의 주파수 의존성을 평가하기 위한 양팔 샌드위치보 시험법의 연구)

  • 김광우;박진택;이덕보;최낙삼
    • Composites Research
    • /
    • v.14 no.3
    • /
    • pp.69-76
    • /
    • 2001
  • This paper proposes a double cantilever sandwich-beam method fur evaluating the frequency dependence of dynamic characteristics of rubbers. The flexural vibration of a double cantilever sandwich-beam specimen with an inserted rubber layer was studied using a finite element simulation in combination with the sine-sweep test. Quadratic relationships of dynamic elastic modulus and material loss factor of rubbers with frequency were suggested employing the least square error method.

  • PDF

Estimators Shrinking towards Projection Vector for Multivariate Normal Mean Vector under the Norm with a Known Interval

  • Baek, Hoh Yoo
    • Journal of Integrative Natural Science
    • /
    • v.11 no.3
    • /
    • pp.154-160
    • /
    • 2018
  • Consider the problem of estimating a $p{\times}1$ mean vector ${\theta}(p-r{\geq}3)$, r = rank(K) with a projection matrix K under the quadratic loss, based on a sample $Y_1$, $Y_2$, ${\cdots}$, $Y_n$. In this paper a James-Stein type estimator with shrinkage form is given when it's variance distribution is specified and when the norm ${\parallel}{\theta}-K{\theta}{\parallel}$ is constrain, where K is an idempotent and symmetric matrix and rank(K) = r. It is characterized a minimal complete class of James-Stein type estimators in this case. And the subclass of James-Stein type estimators that dominate the sample mean is derived.

Constrained Bayes and Empirical Bayes Estimator Applications in Insurance Pricing

  • Kim, Myung Joon;Kim, Yeong-Hwa
    • Communications for Statistical Applications and Methods
    • /
    • v.20 no.4
    • /
    • pp.321-327
    • /
    • 2013
  • Bayesian and empirical Bayesian methods have become quite popular in the theory and practice of statistics. However, the objective is to often produce an ensemble of parameter estimates as well as to produce the histogram of the estimates. For example, in insurance pricing, the accurate point estimates of risk for each group is necessary and also proper dispersion estimation should be considered. Well-known Bayes estimates (which is the posterior means under quadratic loss) are underdispersed as an estimate of the histogram of parameters. The adjustment of Bayes estimates to correct this problem is known as constrained Bayes estimators, which are matching the first two empirical moments. In this paper, we propose a way to apply the constrained Bayes estimators in insurance pricing, which is required to estimate accurately both location and dispersion. Also, the benefit of the constrained Bayes estimates will be discussed by analyzing real insurance accident data.

A Computation Method of B-coefficient With Static Voltage Dependent Load Model (정적 전압의존형 부하모델을 적용한 B계수 산정법)

  • Lee, Myung-Hwan;Chae, Myung-Suk;Shin, Joong-Rin
    • Proceedings of the KIEE Conference
    • /
    • 1997.11a
    • /
    • pp.218-220
    • /
    • 1997
  • In power system, economic dispatch problem is to minimize fuel cost with inequality constraints of generator output. To solve this problem it is very important to express power loss equation that have Quadratic function of generator power included B-coefficient. This paper presents a method in determining B-coefficient by use A-matrix that is calculated by power flow considering voltage dependent static load model. The proposed algorithm is tested with IEEE 6 bus sample system, which shows the result in each cases by the change of load component factor.

  • PDF

An Economic Selective Assembly Procedure for Two Mating Components (짝이 되는 두 부품의 경제적 선택조립 절차)

  • 권혁무;김광재
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.24 no.1
    • /
    • pp.39-48
    • /
    • 1999
  • An economic procedure of selective assembly is proposed when a product is composed of two mating components. The major qualify characteristic of the product is the clearance between the two components. The components are divided into several classes prior to assembly. The component characteristics are assumed to be independently and normally distributed with equal variance. The procedure is designed so that the proportions of both components in their corresponding classes are the same. A cost model is developed based on a quadratic loss function and methods of obtaining the optimal class limits as well as the optimal number of classes are provided. Formulas for obtaining the proportion of rejection and the unavailability of mating components are also provided. The proposed model is compared with the equal width and the equal area partitioning methods using a numerical example.

  • PDF

Variable selection in censored kernel regression

  • Choi, Kook-Lyeol;Shim, Jooyong
    • Journal of the Korean Data and Information Science Society
    • /
    • v.24 no.1
    • /
    • pp.201-209
    • /
    • 2013
  • For censored regression, it is often the case that some input variables are not important, while some input variables are more important than others. We propose a novel algorithm for selecting such important input variables for censored kernel regression, which is based on the penalized regression with the weighted quadratic loss function for the censored data, where the weight is computed from the empirical survival function of the censoring variable. We employ the weighted version of ANOVA decomposition kernels to choose optimal subset of important input variables. Experimental results are then presented which indicate the performance of the proposed variable selection method.

A Conceptual Thesis on the Quality and Quality Control under Recent Manufacturing Environment (최근 기업 여건 하(下)의 품질 및 품질관리에 대한 개념정립에 관한 고찰)

  • Jeon, Tae Bo
    • Journal of Industrial Technology
    • /
    • v.11
    • /
    • pp.125-133
    • /
    • 1991
  • A study to synthesize the recent concept and significance of quality and quality control has been performed in this paper. With understanding the recent market and manufacturing environment, we first discuss the significance of quality from the system view point. Then the existing definitions of quality have been rigourously examined and some significant features embeded in them have been derived. Through this examination, we specifically address "endless-effort for improvement" with three key elements required for successful implementation in quality control programs. Taguchi's quadratic loss function with regard to the addressed quality concept has also been discussed. Finally, we conclude this study with providing a view toward the development of new models.

  • PDF

Hydrodynamic analysis of a floating body with an open chamber using a 2D fully nonlinear numerical wave tank

  • Uzair, Ahmed Syed;Koo, Weon-Cheol
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.4 no.3
    • /
    • pp.281-290
    • /
    • 2012
  • Hydrodynamic analysis of a surface-piercing body with an open chamber was performed with incident regular waves and forced-heaving body motions. The floating body was simulated in the time domain using a 2D fully nonlinear numerical wave tank (NWT) technique based on potential theory. This paper focuses on the hydrodynamic behavior of the free surfaces inside the chamber for various input conditions, including a two-input system: both incident wave profiles and forced body velocities were implemented in order to calculate the maximum surface elevations for the respective inputs and evaluate their interactions. An appropriate equivalent linear or quadratic viscous damping coefficient, which was selected from experimental data, was employed on the free surface boundary inside the chamber to account for the viscous energy loss on the system. Then a comprehensive parametric study was performed to investigate the nonlinear behavior of the wave-body interaction.

An Optimization Method using Evolutionary Computation in Large Scale Power Systems (진화연산을 이용한 대규모 전력계통의 최적화 방안)

  • You, Seok-Ku;Park, Chang-Joo;Kim, Kyu-Ho;Lee, Jae-Gyu
    • Proceedings of the KIEE Conference
    • /
    • 1996.07b
    • /
    • pp.714-716
    • /
    • 1996
  • This paper presents an optimization method for optimal reactive power dispatch which minimizes real power loss and improves voltage profile of power systems using evolutionary computation such as genetic algorithms(GAs), evolutionary programming(EP). and evolution strategy(ES). Many conventional methods to this problem have been proposed in the past, but most these approaches have the common defect of being caught to a local minimum solution. Recently, global search methods such as GAs, EP, and ES are introduced. The proposed methods were applied to the IEEE 30-bus system. Each simulation result, compared with that obtained by using a conventional gradient-based optimization method, Sequential Quadratic Programming (SQP), shows the possibility of applications of evolutionary computation to large scale power systems.

  • PDF

A Risk Metric for Failure Cause in FMEA under Time-Dependent Failure Occurrence and Detection (FMEA에서 고장발생 및 탐지시간을 고려한 고장원인의 위험평가 척도)

  • Kwon, Hyuck Moo;Hong, Sung Hoon;Lee, Min Koo
    • Journal of Korean Society for Quality Management
    • /
    • v.47 no.3
    • /
    • pp.571-582
    • /
    • 2019
  • Purpose: To develop a risk metric for failure cause that can help determine the action priority of each failure cause in FMEA considering time sequence of cause- failure- detection. Methods: Assuming a quadratic loss function the unfulfilled mission period, a risk metric is obtained by deriving the failure time distribution. Results: The proposed risk metric has some reasonable properties for evaluating risk accompanied with a failure cause. Conclusion: The study may be applied to determining action priorities among all the failure causes in the FMEA sheet, requiring further studies for general situation of failure process.