• 아동학회지
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• 제22권3호
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• pp.257-270
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• 2001

The present study examined the relation between academic help-seeking behaviors and classroom context based on students' perceptions of various classroom goals stressed by their teachers and their perceived teacher support for seeking help. The 305 subjects were 5th grade students(162 boys and 143 girls) of an elementary school in Gwangyang. The students completed a questionnaire. Data were analyzed by $2{\times}2$ ANOVA. Results showed that students' help-seeking behaviors were influenced by their teachers' goal orientation and perceived teacher support for seeking help. The results of this study suggest that perceived teacher support for seeking help may be expecially important for some students who could use instrumental help to continue task engagement, and teachers' learning-focused goal orientation is an important variable of instrumental help-seeking behavior.

• 제어로봇시스템학회논문지
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• 제8권7호
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• pp.556-562
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• 2002

This paper studies the identification of a combustion model, which is used to design a linear controller of a steam generation quantity and harmful exhaust gases of a Refuse Incineration Plant(RIP). Even though the RIP has strong nonlinearities and complexities, it is identified as a MIMO parametric ARX model from experimental input-output data sets. Unknown model parameters are decided from experimental input-output data sets, using system identification algorithm based on Instrumental Variables(IV) method. It is shown that the identified model well approximates the input-output combustion characteristics.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국제학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.1045-1050
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• 1988

The problem of applying the linear integral filter in analysis and parameter estimation of linear continuous systems is discussed. A discrete-time model, which is equivalent to that obtained using the bilinear z transformation, is derived and employed to predict system output. It is shown that the output error can be controlled through the sampling interval. In order to obtain unbiased estimates, an instrumental variable (IV) method is proposed, where the instrumental variables are constituted using adaptive filtering. Some problems on implementation of the recursive IV algorithm are discussed. Both theoretical analysis and simulation study are given to illustrate the proposed methods.

• 동력기계공학회지
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• 제3권2호
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• pp.34-41
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• 1999

This paper identifies a linear combustion model of Refuse Incineration Plant(RIP) which characterizes its combustion dynamics, where the proposed model has thirteen-inputs and one-output. The structure of the RIP model is given as an ARX model which obtained from the theoretical analysis. And then, some unknown model parameters are decided from experimental input-output data sets, using system identification algorithm based on Instrumental Variables(IV) method. In result, it is shown that the proposed model well approximates the input-output combustion characteristics riven by experimental data sets.

• 아동학회지
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• 제18권2호
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• pp.311-331
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• 1997

This study investigated the relationship between preschool children's social competence and perceived social support. The subjects were 85 children enrolled in 10 kindergartens and nurseries located in Seoul. Social support was assessed by children themselves with a social support dialogue Cask, "My Family and Friends," developed by Reid, Lamdegman, and Jaccard (1989). This task consists of 12 dialogues based on Vygotskian principles. Social competency was assessed by teachers with a slightly modified version of Song's Iowa Social Competency Scale (ISCS). The data were analyzed by frequencies percentiles, mean, one-way ANOVAs, and Pearson's correlations. Results showed that (1) Children perceived parents to be the best multi-purpose social providers: mothers for emotional support and fathers for instrumental support. (2) Children with unemployed mothers perceived higher maternal emotional, informational, and instrumental support than children with employed mothers. (3) Middle-class children perceived higher friendship support than upper-or lower-class children. (4) Friendship support was the one variable most significantly related to children's social competence.

• 한국의류학회지
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• 제26권3_4호
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• pp.548-559
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• 2002

본 연구에서는 소비자 측면에서 영향을 미치는 중요한 요소인 소비자 특성에 따라 소비후 과정이 달라지는 점에 주목하여 쇼핑가치에 따라 만족을 판단하는 과정에 어떠한 차이를 보이고 있는지를 알아보았다. 본 연구의 자료수집은 대학생을 대상으로 설문지 응답방식을 수집하였으며, 총 614부를 최종 자료분석에 사용하였다. 통계분석을 위하여 군집분석, t-test를 실시하였으며, 제시된 인과모형을 검증하기 위하여 공변량구조모형분석을 이용하였다.

• 응용통계연구
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• 제24권1호
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• pp.11-23
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• 2011

Robust unit root tests are developed for dynamic panels consisting of TAR processes. The test statistics are all based on diverse combinations of individual t-type tests for significance of TAR coefficients. Limiting null distributions are established. A Monte-Carlo experiment compares the proposed tests. The tests are applied to a panel data set of Canadian unemployment rates which show asymmetric features as well as having outliers.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1992년도 한국우주과학회보 제2권1호
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• pp.8-8
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• 1993

Long period eclipsing binary 32 Cygni was photometrically observed in 1992 at Yonsei University Observatory. Instrumental differential magnitude and standardized magnitude of this star show some intrinsic light variations. Some possible explanations will be discussed. BVRI photometric observations show that 30 Cyg may be a variable star. A further monitoring of 30 Cyg is therefore called for justification of such evidences.

• KDI Journal of Economic Policy
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• 제40권1호
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• pp.31-43
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• 2018

There is a large amount of empirical literature reporting that people who regularly attend religious services tend to have better health outcomes. However, it remains an unanswered question as to whether the observed correlation reflects any causality. Exploiting exogenous changes in church attendance driven by law changes in 21 states of the U.S., I find tentative but suggestive evidence that the observed strong correlation between religious participation and health is likely to be driven by endogenous selection.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.90.6-90
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• 2002

An active stick which has the variable force-feel characteristics is developed. A combined position and force control strategy is mechanized using a 2-axis built-in force sensor and LVDT. The 2-axis force sensor which measures the stick force felt by the operator is developed by using strain gages and appropriate instrumental amplifiers. A mathematical model of the active stick dynamics is derived, and compared with the experimental results. The frictional torque of the stick due to the mechanical contacts of several parts makes the experimental frequency responses to be dependent on the magnitude of excitation signal, and the precision closed loop control to be difficult. A friction observe...