• Journal of the Korean Statistical Society
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• 제21권2호
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• pp.153-166
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• 1992

Consider an unknown regression function f of the response Y on a d-dimensional measurement variable X. It is assumed that f belongs to a tensor Sobolev space. Let T denote a differential operator. Let $\hat{T}_n$ denote an estimator of T(f) based on a random sample of size n from the distribution of (X, Y), and let $\Vert \hat{T}_n - T(f) \Vert_2$ be the usual $L_2$ norm of the restriction of $\hat{T}_n - T(f)$ to a subset of $R^d$. Under appropriate regularity conditions, the optimal rate of convergence for $\Vert \hat{T}_n - T(f) \Vert_2$ is discussed.

• Journal of the Korean Statistical Society
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• 제26권1호
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• pp.1-22
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• 1997

In the linear regression model $y_{i}$ = .alpha. $x_{i}$ $^{T}$ .beta. + .epsilon.$_{i}$ , i = 1,2,...,n, the weighted pairwise absolute deviation (WPAD) estimator was defined by minimizing the dispersion function D (.beta.) = .sum..sum.$_{{i $w_{{ij}}$$\mid$ $r_{j}$ (.beta.) $r_{i}$ (.beta.)$\mid$, where $r_{i}$ (.beta.)'s are residuals and $w_{{ij}}$'s are weights. This estimator can achive bounded total influence with positive breakdown by choice of weights $w_{{ij}}$. In this paper, we consider a more general type of dispersion function than that of D(.beta.) and propose a pairwise GM-estimator based on the dispersion function. Under some regularity conditions, the proposed estimator has a bounded influence function, a high breakdown point, and asymptotically a normal distribution. Results of a small-sample Monte Carlo study are also presented. presented.

• Journal of the Korean Statistical Society
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• 제29권3호
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• pp.351-360
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• 2000

This paper considers the problem of testing a variance change in infinite order autoregressive models. A cusum of squares test based on the residuals from an AR(q) model is constructed analogous to Inclan and Tiao (1994)'s test statistic, where q is a sequence of positive integers diverging to $\infty$. It is shown that under regularity conditions the limiting distribution of the test statistic is the sup of a standard Brownian bridge. Simulation results are given to illustrate the performance of the test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.124-126
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• 2002

The general capacitor placement problem is a combinatorial optimization problem having an objective function composed of power losses and capacitor installation costs subject to bus voltage constraints. In this paper, the method employing the chaos search algorithm is proposed to solve optimal capacitor placement problem with reducing computational effort and enhancing optimality of the solution. Chaos method in optimization problem searches the global optimal solution on the regularity of chaotic motions and easily escapes from local or near optimal solution than stochastic optimization algorithms. The chaos optimization method is tested on 9 buses and 69 buses system to illustrate the effectiveness of the proposed method.

• Journal of the Korean Statistical Society
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• 제26권4호
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• pp.507-520
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• 1997

In this paper we propose a robust Wald-type test which is based on an efficient Mallows-type one-step GM-estimator. The proposed estimator based on the weight function of Song, Park and Nam (1996) has a bounded influence function and a high breakdown point. Under some regularity conditions, we compute the finite-sample breakdown point, and drive asymptotic normality of the proposed estimator. The level and power breakdown points, influence function and asymptotic distribution of the proposed test statistic are main points of this paper. To compare the performance of the proposed test with other tests, we perform some Monte Carlo simulations.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.729-731
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• 2008

Three-dimensional unsteady simulation using RNG $\kappa-\varepsilon$ turbulence model is used in full flow passage of model Kaplan turbine. Then the pressure pulsation is obtained. Monitoring data of pressure pulsation in the turbine is obtained through experiment and is compared with the numerical simulation. And a good coherence is shown between the simulation and the experiment. Then the regularity of the pressure pulsation s distribution and transmission in the turbine is discussed in detail.

• 한국초등과학교육학회지:초등과학교육
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• 제36권3호
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• pp.256-272
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• 2017

The purpose of this research is to study and learn more features how this type of distribution for communication in $6^{th}$ grade first semester elementary science and mathematics according to communicative expression by 2009 revised curriculum. For this study, based on an analysis standard presented in previous research on the types of communication. The results of this research are as follows. First, because the mathematics presents the number of ways to communicate twice more than science, mathematics go through with much more problems to solve than science. Second, in mathematics, spoken method and written method have similar proportion, less in physical activity method. Third, Science showed balanced proportion among four areas; earth, life, energy, and material. On the other hand, mathematics only showed small numbers in the area of geometry but similar numbers in number and operations, regularity, measurement. Fourth, there is no common feature or relevance about communicative approach for convergence thinking in 2009 revised curriculum, it seems that it doesn't consider it as a revised.

• 한국식생활문화학회지
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• 제28권3호
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• pp.282-292
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• 2013

The purpose of this study is to identify a suitable organizational diagnostic model for analyzing the management efficiency of food service firms. We used the three-iteration Delphi technique on a panel of 19 business employees, 7 industry experts, and 4 employees in the food service industry. A total of 36 assessment indicators were developed through this panel, with numerous major findings. First, it is important to evaluate the leadership qualities of employees in terms of their motivation and competency. Second, it is important to evaluate the ability of employees to interface well with other employees. Third, it is important to evaluate and manage the brand image recognized by customers. Fourth, it is important to evaluate the fairness and regularity of the rewards given for an excellent job performance. Fifth, it is important to evaluate the level of communication and information distribution in the organizational culture. Last, but not least, it is important to evaluate the transparency and fairness of an organization in its human resource management (HRM) and the efficiency of its organizational structure. In conclusion, this study empirically shows how food service firms can develop an organizational diagnostic model to increase their managerial efficiency.

• The Journal of Asian Finance, Economics and Business
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• 제5권3호
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• pp.157-167
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• 2018

This research aims to generalize the conceptual basis of precariousness of employment, study the factors and scale of unsustainable of employment in the countries of the Eurasian Economic Union (EAEU). The concept of precariousness of employment is formed in social and economic studies about 40 years ago, but objective and subjective conditions and forms of unsustainable employment existed before. This study proposes a classification of forms of precariousness of employment on 16 criteria: the duration and timing of agreements, contract terms, the nature of income; the degree of labor autonomy; the level of formality; the level of openness; the level of vulnerability; the conditions of growth of qualification; the level of flexibility; the level of stability; regularity; the severity of the danger of work; in relation to the workplace; the quality of employment, the level of social security. In this research highlighted factors (globalization, demography, migration, structure factors, shadow and informal economy, social development and living standards, unemployment), and systematized certain trends of precariousness of employment, channels and means, forms of manifestation. The empirical analysis identified of the labor potential of the Eurasian countries and new quantitative estimates of the levels of unsustainable employment in the Eurasian Economic Space.

• Journal of the Korean Data and Information Science Society
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• 제22권5호
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• pp.839-847
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• 2011

이 연구에서는 다중 선형회귀 모형에서 자기공분산에 근거한 회귀 계수의 추정량을 도출하였다. 자기공분산에 근거한 방법은 Park (2009)에 제시된 방법으로 직관적으로 매혹적이지는 않지만, 이것에 근거한 추정량이 회귀 계수의 불편추정량이 된다. 설명변수 벡터가 어떤 정칙조건을 만족한다면, 오차가 자기회귀이동평균 모형을 따르면 만족되는 약한 조건 하에서 이 추정량이 최소제곱 추정량과 점근적으로 동일한 분포를 가지며 또한 회귀 계수에 확률 상 수렴한다는 것을 보였다. 마지막으로 모의실험을 통해 이 성질들이 소표본에서도 성립하는 것을 보였다.