• Title/Summary/Keyword: asymmetric methods

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Study on the Case of the Asymmetric War (비대칭전 주요사례 연구)

  • Kim, Sung Woo
    • Convergence Security Journal
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    • v.16 no.6_1
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    • pp.25-32
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    • 2016
  • We can not respond asymmetric warfare effectively. The asymmetric operation is performed in asymmetric methods and means with different characteristics and functions to their enemy. And the character of the asymmetric operation have 'heterogeneity' and 'superiority' in principle. The type of asymmetric strategy is complex and diverse. Since we can classify the type of the asymmetric strategy in many different way and we must study in many ways and aspects. When we study asymmetric war previous cases from modern to ancient era, we can find that the key factors of the victory have superiority of the asymmetric strategy and discriminatory measures. The asymmetry is created when one party has to adapt to the strategic environment. If we want to secure a strategic advantage, we must take a number of case studies and countermeasures for asymmetric warfare.

Rank Scores for Linear Models under Asymmetric Distributions

  • Choi, Young-Hun
    • Communications for Statistical Applications and Methods
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    • v.13 no.2
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    • pp.359-368
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    • 2006
  • In this paper we derived the asymptotic relative efficiency, ARE(ms, rs), of our new score function with respect to the McKean and Sievers scores for the asymmetric error distributions which often occur in practice. We thoroughly explored the asymptotic relative efficiency, ARE(ms, rs), of our score function that provides much improvement over the McKean and Sievers scores for all values of r and s under asymmetric distributions.

New Calibration Methods with Asymmetric Data

  • Kim, Sung-Su
    • The Korean Journal of Applied Statistics
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    • v.23 no.4
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    • pp.759-765
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    • 2010
  • In this paper, two new inverse regression methods are introduced. One is a distance based method, and the other is a likelihood based method. While a model is fitted by minimizing the sum of squared prediction errors of y's and x's in the classical and inverse methods, respectively. In the new distance based method, we simultaneously minimize the sum of both squared prediction errors. In the likelihood based method, we propose an inverse regression with Arnold-Beaver Skew Normal(ABSN) error distribution. Using the cross validation method with an asymmetric real data set, two new and two existing methods are studied based on the relative prediction bias(RBP) criteria.

Charge Balance Control Methods for a Class of Fundamental Frequency Modulated Asymmetric Cascaded Multilevel Inverters

  • Babaei, Ebrahim
    • Journal of Power Electronics
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    • v.11 no.6
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    • pp.811-818
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    • 2011
  • Modulation strategies for multilevel inverters have typically focused on synthesizing a desired set of sinusoidal voltage waveforms using a fixed number of dc voltage sources. This makes the average power drawn from different dc voltage sources unequal and time varying. Therefore, the dc voltage sources are unregulated and require that corrective control action be incorporated. In this paper, first two new selections are proposed for determining the dc voltage sources values for asymmetric cascaded multilevel inverters. Then two modulation strategies are proposed for the dc power balancing of these types of multilevel inverters. Using the charge balance control methods, the power drawn from all of the dc sources are balanced except for the dc source used in the first H-bridge. The proposed control methods are validated by simulation and experimental results on a single-phase 21-level inverter.

Asymmetric Robustness Bounds of Eigenvalue Distribution for Uncertain Linear Systems (불확실한 선형시스템 고유값 배치의 비대칭 강인한계)

  • 이재천
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.7
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    • pp.794-799
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    • 1999
  • This study deals with robustness bounds estimation for uncertain linear systems with structured perturbations where the eigenvalues of the perturbed systems are guaranteed to stay in a prescribed region. Based upon the Lyapunov approach, new theorems to estimate allowable perturbation parameter bounds are derived. The theorems are referred to as the zero-order or first-order asymmetric robustness measure depending on the order of the P matrix in the sense of Taylor series expansion of perturbed Lyapunov equation. It is proven that Gao's theorem for the estimation of stability robustness bounds is a special case of proposed zero-order asymmetric robustness measure for eigenvalue assignment. Robustness bounds of perturbed parameters measured by the proposed techniques are asymmetric around the origin and less conservative than those of conventional methods. Numerical examples are given to illustrate proposed methods.

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Construction of bivariate asymmetric copulas

  • Mukherjee, Saikat;Lee, Youngsaeng;Kim, Jong-Min;Jang, Jun;Park, Jeong-Soo
    • Communications for Statistical Applications and Methods
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    • v.25 no.2
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    • pp.217-234
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    • 2018
  • Copulas are a tool for constructing multivariate distributions and formalizing the dependence structure between random variables. From copula literature review, there are a few asymmetric copulas available so far while data collected from the real world often exhibit asymmetric nature. This necessitates developing asymmetric copulas. In this study, we discuss a method to construct a new class of bivariate asymmetric copulas based on products of symmetric (sometimes asymmetric) copulas with powered arguments in order to determine if the proposed construction can offer an added value for modeling asymmetric bivariate data. With these newly constructed copulas, we investigate dependence properties and measure of association between random variables. In addition, the test of symmetry of data and the estimation of hyper-parameters by the maximum likelihood method are discussed. With two real example such as car rental data and economic indicators data, we perform the goodness-of-fit test of our proposed asymmetric copulas. For these data, some of the proposed models turned out to be successful whereas the existing copulas were mostly unsuccessful. The method of presented here can be useful in fields such as finance, climate and social science.

Use of Lèvy distribution to analyze longitudinal data with asymmetric distribution and presence of left censored data

  • Achcar, Jorge A.;Coelho-Barros, Emilio A.;Cuevas, Jose Rafael Tovar;Mazucheli, Josmar
    • Communications for Statistical Applications and Methods
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    • v.25 no.1
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    • pp.43-60
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    • 2018
  • This paper considers the use of classical and Bayesian inference methods to analyze data generated by variables whose natural behavior can be modeled using asymmetric distributions in the presence of left censoring. Our approach used a $L{\grave{e}}vy$ distribution in the presence of left censored data and covariates. This distribution could be a good alternative to model data with asymmetric behavior in many applications as lifetime data for instance, especially in engineering applications and health research, when some observations are large in comparison to other ones and standard distributions commonly used to model asymmetry data like the exponential, Weibull or log-logistic are not appropriate to be fitted by the data. Inferences for the parameters of the proposed model under a classical inference approach are obtained using a maximum likelihood estimators (MLEs) approach and usual asymptotical normality for MLEs based on the Fisher information measure. Under a Bayesian approach, the posterior summaries of interest are obtained using standard Markov chain Monte Carlo simulation methods and available software like SAS. A numerical illustration is presented considering data of thyroglobulin levels present in a group of individuals with differentiated cancer of thyroid.

Correlation between the Asymmetric Ratio of Occlusal Force and the Thickness of the Middle Scalene Muscle (교합력 비대칭률과 중간 목갈비근 근육 두께의 비대칭률 상관관계)

  • Chae, Jung-Byung;Cho, Hyun-Rae
    • PNF and Movement
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    • v.14 no.1
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    • pp.53-57
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    • 2016
  • Purpose: This study aimed to examine the correlation between the asymmetric ratio of occlusal force of the temporomandibular joint and the thickness of the middle scalene muscle. Methods: The study measured the occlusal force of the right and left temporomandibular joints in 30 subjects (12 males and 18 females). Pearson's correlation analysis was performed to examine the effect of occlusal force on the asymmetric ratio of the thickness of their middle scalene muscles by measuring the force using ultrasound after the break. Results: The correlation between the asymmetric ratio of occlusal force and muscle thickness is 0.41, according to Pearson's correlation coefficient. Therefore, the result shows a moderate correlation with the asymmetric ratio of the temporomandibular joint depending on differences in the thickness of the middle scalene muscle. Conclusion: Based on the above results, the asymmetric ratio of occlusal force was found to correlate with the thickness of the middle scalene muscle. Thus, therapeutic intervention is required for the middle scalene muscle in the case of temporomandibular joint disorder.

Modified Modal Methods for Sensitivity Analysis of Asymmetric Damped System (비대칭 감쇠 시스템의 민감도 해석을 위한 개선된 모드법)

  • Moon, Yeong-Jong;Jo, Ji-Seong;Oh, Ju-Won;Lee, In-Won
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.530-533
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    • 2004
  • It is well known that many real systems have asymmetric mass, damping and stiffness matrices. In this case, the method for calculating eigenpair sensitivity is different from that of symmetric system. To determine the derivatives of the eigenpairs in asymmetric damped case, a modal method was recently developed by Adhikari. When a dynamic system has many degrees of freedom, only a few lower modes are available, and because the higher modes should be truncated to use the modal method, the errors may become significant. In this paper a procedure for determining the sensitivities of the eigenpairs of asymmetric damped system using a few lowest set of modes is proposed. Numerical examples show that proposed method achieves better calculating efficiency and highly accurate results when a few modes are used.

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A Modified Definition on the Process Capability Index Cpk Based on Median

  • Park, Hyo-Il
    • Communications for Statistical Applications and Methods
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    • v.18 no.4
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    • pp.527-535
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    • 2011
  • This study proposes a modified definition about $C_{pk}$ based on median as the centering parameter in order to more easily control the process since the mean does not represent any quantile of the asymmetric process distribution. Then we consider an estimate and derive the asymptotic normality for the estimate of the modified $C_{pk}$. In addition, we provide an example with asymmetric distributions and discuss the estimation for the limiting variance that are followed by some concluding remarks.