• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.8
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• pp.42-47
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• 2006

In this paper, we propose a sliding mode control with the bound estimation for robot manipulators without requiring exact knowledge of the robot dynamics. For the bound estimation, the upper bound of the uncertain nonlinearities of robot dynamics is represented as a Fredholm integral equation of the first kind and we propose an adaptive scheme which is only dependent on the sliding surface function. Also, we prove the asymptotic stability for the robot systems using two important properties in the robot dynamics: skew-symmetry and positive-definiteness of robot parameters.

• Bulletin of the Korean Mathematical Society
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• v.36 no.3
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• pp.543-564
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• 1999

Consider a symmetric bilinear form defined on $\prod\times\prod$ by $_{\lambda\mu}$ = $<\sigma,fg>\;+\;\lambdaL[f](a)L[g](a)\;+\;\muM[f](b)m[g](b)$ ,where $\sigma$ is a quasi-definite moment functional, L and M are linear operators on $\prod$, the space of all real polynomials and a,b,$\lambda$ , and $\mu$ are real constants. We find a necessary and sufficient condition for the above bilinear form to be quasi-definite and study various properties of corresponding orthogonal polynomials. This unifies many previous works which treated cases when both L and M are differential or difference operators. finally, infinite order operator equations having such orthogonal polynomials as eigenfunctions are given when $\mu$=0.

• Annual Conference on Human and Language Technology
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• 2001.10d
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• pp.457-461
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• 2001

본 논문은 동사의 의미표상과 명사의 한정성의 강호관계를 중심으로 목적어의 생략현상을 검토하였다. 한국어는 영어 같은 언어와 달리 주어, 목적어 등이 자주 생략된다. 이 연구는 한국어의 목적어 생략이 단순히 인간성 (humanness), 주체성 (agency), 한정성(definiteness) 등 명사의 의미자질에 의해서만 결정되는 것이 아니라, 다음 두 가지 제약이 결정적으로 작용함을 제안하고자 한다. 첫째, 목적어 생략은 행동양상 (mold of agent act)과 원인 (cause)을 심층적으로 포함하는 소위 '핵심 타동사 (core transitive)'와 선행사의 한정성 정도에 의해 결정되는데, 구체적으로 목적어 생략은 한정성 자질을 가진 선행사가 없는 담화에서는 허용되지 않는다는 제약이다. 둘째, 타동사와 명사의 한정성과는 독립적으로, 한국어의 목적어 생략은 또한, 추론에 의거하여 보다 더 적절히 해석될 수 있는 경우를 실증적으로 보이고자 한다.

• Language and Information
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• v.19 no.1
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• pp.1-18
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• 2015

Korean marks case for subjects and objects, but it is well known that case-markers can be dropped in certain contexts. Kwon and Zribi-Hertz (2008) establishes the phenomenon of Korean case drop on a single factor of f(ocus)-structure visibility and claims that both subject and object case drop can fall under a single linguistic generalization of information structure. However, the supporting data is not empirically substantiated and the tenability of the f-structure analysis is still under question. In this paper, an experiment was conducted to show that the specific claims of Kwon and Zribi-Hertz's analysis that places exclusive importance on information structure cannot be adequately supported by empirical evidence. In addition, the present study examines H. Lee's (2006a, 2006c) multi-factor analysis of object case drop and investigates whether this approach can subsume both subject and object case drop under a unified analysis. The present findings indicate that the multi-factor analysis that involves the interaction of independent factors (Focus, Animacy, and Definiteness) is also compatible with subject case drop, and that judgments on case drop are not categorical but form gradient statistical preferences.

• Communications for Statistical Applications and Methods
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• v.24 no.1
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• pp.81-96
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• 2017

Cumulative logit random effects models are typically used to analyze longitudinal ordinal data. The random effects covariance matrix is used in the models to demonstrate both subject-specific and time variations. The covariance matrix may also be homogeneous; however, the structure of the covariance matrix is assumed to be homoscedastic and restricted because the matrix is high-dimensional and should be positive definite. To satisfy these restrictions two Cholesky decomposition methods were proposed in linear (mixed) models for the random effects precision matrix and the random effects covariance matrix, respectively: modified Cholesky and moving average Cholesky decompositions. In this paper, we use these two methods to model the random effects precision matrix and the random effects covariance matrix in cumulative logit random effects models for longitudinal ordinal data. The methods are illustrated by a lung cancer data set.

• Communications for Statistical Applications and Methods
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• v.21 no.2
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• pp.169-181
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• 2014

Marginalized random effects models (MREM) are commonly used to analyze longitudinal categorical data when the population-averaged effects is of interest. In these models, random effects are used to explain both subject and time variations. The estimation of the random effects covariance matrix is not simple in MREM because of the high dimension and the positive definiteness. A relatively simple structure for the correlation is assumed such as a homogeneous AR(1) structure; however, it is too strong of an assumption. In consequence, the estimates of the fixed effects can be biased. To avoid this problem, we introduce one approach to explain a heterogenous random effects covariance matrix using a modified Cholesky decomposition. The approach results in parameters that can be easily modeled without concern that the resulting estimator will not be positive definite. The interpretation of the parameters is sensible. We analyze metabolic syndrome data from a Korean Genomic Epidemiology Study using this method.

• Language and Information
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• v.11 no.2
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• pp.23-47
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• 2007

In this paper I discuss two markers for specificity, etten and han, in Korean. First, I discuss their structural properties and claim that etten is a determiner, and han is a numeral preceded by an implicit existential quantifier. Then I discuss four uses of etten and two uses of han, and show when they are used as specificity markers. There are various properties of the two specificity markers, some of which they have in common. I take them as properties of specificity markers in general. The properties only one of them has are taken to come from the original meanings of the two morphemes. I claim that specific indefinites range over individual concepts, which lead to the properties they have in common.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.471-474
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• 2007

A domain/boundary decomposition technique is applied to carry out efficient finite element analyses of 3-D contact problems. Appropriate penalty functions are selected for connecting an interface and contact interfaces with neighboring subdomains that satisfy continuity constraints. As a consequence, all the effective stiffness matrices have positive definiteness, and computational efficiency can be improved to a considerable degree. If necessary, any complex-shaped 3-D domain can be divided into several simple-shaped subdomains without considering the conformity of meshes along the interface. With a set of numerical examples, the basic characteristics of computational efficiency are investigated carefully.

• Management & Information Systems Review
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• v.19
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• pp.199-221
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• 2006

The purpose of this study is to expand businesses' adoption of the Enterprise Resource Planning System (E.R.P.S.). In order to accomplish the objective, the following conditions need to be fulfilled. 1) Clearness of the goal and expected effect of E.R.P.S. adoption 2) Definiteness of the extent of E.R.P.S. construction 3) The management's will to E.R.P.S. adoption If the E.R.P.S is adopted, the following effects are expected. 1) Speedy quality decision-making is possible. 2) Time taken from the order of the product to its release can be curtailed (from 40days to 10days). 3) Time taken for the development of the product can be shortened (from 24 months to 10 months). 4) Cost reduction is possible by using necessary information in real time.

• Macromolecular Research
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• v.9 no.3
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• pp.164-170
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• 2001

Recently in order to describe the complex rheological behavior of polymer melts with long side branches like low density polyethylene, new constitutive equations called the pom-pom equations have been derived by McLeish and Larson on the basis of the reptation dynamics with simplified branch structure taken into account. In this study mathematical stability analysis under short and high frequency wave disturbances has been performed for the simplified differential version of these constitutive equations. It is proved that they are globally Hadamard stable except for the case of maximum constant backbone stretch (λ = q) with arm withdrawal s$\_$c/ neglected, as long as the orientation tensor remains positive definite or the smooth strain history in the now is previously given. However this model is dissipative unstable, since the steady shear How curves exhibit non-monotonic dependence on shear rate. This type of instability corresponds to the nonlinear instability in simple shear flow under finite amplitude disturbances. Additionally in the flow regime of creep shear flow where the applied constant shear stress exceeds the maximum achievable value in the steady now curves, the constitutive equations will possibly violate the positive definiteness of the orientation tensor and thus become Hadamard unstable.