• Title/Summary/Keyword: random variable

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Nonlinear control system using universal learning network with random search method of variable search length

  • Shao, Ning;Hirasawa, Kotaro;Ohbayashi, Masanao;Togo, Kazuyuki
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.235-238
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    • 1996
  • In this paper, a new optimization method which is a kind of random searching is presented. The proposed method is called RasVal which is an abbreviation of Random Search Method with Variable Seaxch Length and it can search for a global minimum based on the probability density functions of searching, which can be modified using informations on success or failure of the past searching in order to execute intensified and diversified searching. By applying the proposed method to a nonlinear crane control system which can be controlled by the Universal Learning Network with radial basis function(R.B.P.), it has been proved that RasVal is superior in performance to the commonly used back propagation learning algorithm.

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Variable Selection in Linear Random Effects Models for Normal Data

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.27 no.4
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    • pp.407-420
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    • 1998
  • This paper is concerned with selecting covariates to be included in building linear random effects models designed to analyze clustered response normal data. It is based on a Bayesian approach, intended to propose and develop a procedure that uses probabilistic considerations for selecting premising subsets of covariates. The approach reformulates the linear random effects model in a hierarchical normal and point mass mixture model by introducing a set of latent variables that will be used to identify subset choices. The hierarchical model is flexible to easily accommodate sign constraints in the number of regression coefficients. Utilizing Gibbs sampler, the appropriate posterior probability of each subset of covariates is obtained. Thus, In this procedure, the most promising subset of covariates can be identified as that with highest posterior probability. The procedure is illustrated through a simulation study.

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Reducing the PAPR of OFDM Systems by Random Variable Transformation

  • Taher, Montadar Abas;Singh, Mandeep Jit;Ismail, Mahamod Bin;Samad, Salina Abdul;Islam, Mohammad Tariqul
    • ETRI Journal
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    • v.35 no.4
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    • pp.714-717
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    • 2013
  • Peak power reduction techniques in orthogonal frequency division multiplexing (OFDM) has been an important subject for many researchers for over 20 years. In this letter, we propose a side-information-free technique that is based on the concept of random variable (RV) transformation. The suggested method transforms RVs into other RVs, aiming to reshape the constellation that will consequently produce OFDM symbols with a reduced peak-to-average power ratio. The proposed method has no limitation on the mapping type or the mapping order and has no significant effect on the bit error rate performance compared to other methods presented in the literature. Additionally, the computational complexity does not increase.

A STRONG LAW OF LARGE NUMBERS FOR AANA RANDOM VARIABLES IN A HILBERT SPACE AND ITS APPLICATION

  • Ko, Mi-Hwa
    • Honam Mathematical Journal
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    • v.32 no.1
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    • pp.91-99
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    • 2010
  • In this paper we introduce the concept of asymptotically almost negatively associated random variables in a Hilbert space and obtain the strong law of large numbers for a strictly stationary asymptotically almost negatively associated sequence of H-valued random variables with zero means and finite second moments. As an application we prove a strong law of large numbers for a linear process generated by asymptotically almost negatively random variables in a Hilbert space with this result.

Sub-gaussian Techniques in Obtaining Laws of Large Numbers in $L^1$(R)

  • Lee, Sung-Ho;Lee, Robert -Taylor
    • Journal of the Korean Statistical Society
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    • v.23 no.1
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    • pp.39-51
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    • 1994
  • Some exponential moment inequalities for sub-gaussian random variables are studied in this paper. These inequalities are used to obtain laws of large numbers for random variable and random elements in $L^1(R)$.

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On Estimating of Kullback-Leibler Information Function using Three Step Stress Accelerated Life Test

  • Park, Byung-Gu;Yoon, Sang-Chul;Cho, Ji-Young
    • International Journal of Reliability and Applications
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    • v.1 no.2
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    • pp.155-165
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    • 2000
  • In this paper, we propose some estimators of Kullback- Leibler Information functions using the data from three step stress accelerated life tests. This acceleration model is assumed to be a tampered random variable model. Some asymptotic properties of proposed estimators are proved. Simulations are performed for comparing the small sample properties of the proposed estimators under use condition of accelerated life test.

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A Dynamic Discount Approach to the Poisson Process

  • Shim, Joo-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.271-276
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    • 1997
  • A dynamic discount approach is proposed for the estimation of the Poisson parameter and the forecasting of the Poisson random variable, where the parameter of the Poisson distribution varies over time intervals. The recursive estimation procedure of the Poisson parameter is provided. Also the forecasted distribution of the Poisson random variable in the next time interval based on the information gathered until the current time interval is provided.

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A New Estimator for Seasonal Autoregressive Process

  • So, Beong-Soo
    • Journal of the Korean Statistical Society
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    • v.30 no.1
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    • pp.31-39
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    • 2001
  • For estimating parameters of possibly nonlinear and/or non-stationary seasonal autoregressive(AR) processes, we introduce a new instrumental variable method which use the direction vector of the regressors in the same period as an instrument. On the basis of the new estimator, we propose new seasonal random walk tests whose limiting null distributions are standard normal regardless of the period of seasonality and types of mean adjustments. Monte-Carlo simulation shows that he powers of he proposed tests are better than those of the tests based on ordinary least squares estimator(OLSE).

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Minimum Variance Unbiased Estimation for the Maximum Entropy of the Transformed Inverse Gaussian Random Variable by Y=X-1/2

  • Choi, Byung-Jin
    • Communications for Statistical Applications and Methods
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    • v.13 no.3
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    • pp.657-667
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    • 2006
  • The concept of entropy, introduced in communication theory by Shannon (1948) as a measure of uncertainty, is of prime interest in information-theoretic statistics. This paper considers the minimum variance unbiased estimation for the maximum entropy of the transformed inverse Gaussian random variable by $Y=X^{-1/2}$. The properties of the derived UMVU estimator is investigated.