• Structural Engineering and Mechanics
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• 제3권4호
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• pp.373-382
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• 1995

The weighting strategy has received a great attention and has been widely applied to multicriterion optimization. This gaper examines a global criterion method (GCM) with the weighting objectives strategy in fuzzy structural engineering problems. Fuzziness of those problems are in their design goals, constraints and variables. Most of the constraints are originated from analysis of engineering mechanics. The GCM is verified to be equivalent to fuzzy goal programming via a truss design. Continued and mixed discrete variable spaces are presented and examined using a fuzzy global criterion method (FGCM). In the design process a weighting parameter with fuzzy information is introduced into the design and decision making. We use a uniform machine-tool spindle as an illustrative example in continuous design space. Fuzzy multicriterion optimization in mixed design space is illustrated by the design of mechanical spring stacks. Results show that weighting strategy in FGCM can generate both the best compromise solution and a set of Pareto solutions in fuzzy environment. Weighting technique with fuzziness provides a more relaxed design domain, which increases the satisfying degree of a compromise solution or improves the final design.

• 한국수학교육학회지시리즈A:수학교육
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• 제50권1호
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• pp.103-118
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• 2011

The study examined whether the relation between mathematics self-efficacy and mathematics achievement was partially mediated by the learning strategies, using latent growth model analyses. It was also examined the auto-regressive, cross-lagged (ARCL) panel model for testing the stability and change in the relation of mathematics self-efficacy and learning strategy over time. The study analyzed the first-year to the third-year data of the Korean Educational Longitudinal Survey (KELS). The result of ARCL panel model analysis showed that earlier mathematics self-efficacy could predict later learning strategy use. There were linear trends in mathematics self-efficacy, learning strategy, and mathematics achievement. Specifically, mathematics achievement was increased over the three time points, whereas mathematics self-efficacy and learning strategies were significantly decreased. In the analyses of latent growth models, the mediating effects of learning strategies were overall supported. That is, both of initial status and change rate of rehearsal strategy partially mediated the relation of mathematics self-efficacy and mathematics achievement. However, in elaboration and meta-cognitive strategies, only the initial status of each variable showed the indirect relationship.

• 가족자원경영과 정책
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• 제2권1호
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• pp.15-31
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• 1998

The purpose of study is to understand the home management strategy to cope with rapid changing environments and to verify that how personal value orientation affect home management strategy. The research results are summarized below. First, variables that affect the value orientation of Korean urbanite are sex, area of dwelling, degree of information using and degree of stress recognition in case of material orientation, degree of information using in case of environmental orientation, academic career, sex, degree of information using, degree of stress recognition in cases of fate control orientation, number of children, sex, degree of information using in case of equilibrium orientation, sex, degree of stress recognition in case of present orientation and academic career, degree of stress recognition in case of individualistic orientation. Second, value orientation variables that affect overall home management strategy of Korean urbanite are material orientation, environmental orientation, fate control orientation and individualistic orientation. Third, variables that affect overall home management strategy of Korean urbanite are age, academic career, degree of information using, degree of stress recognition, perception level of living relative to others, environmental orientation and fate control orientation and it is shown that degree of information using is domineering variable.

• 가족자원경영과 정책
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• 제2권2호
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• pp.1-19
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• 1998

The purpose of study is to understand the home management strategy to cope with rapid changing environments and to verify that how personal value orientation affect home management strategy. The research results are summarized below. First, variables that affect the value orientation of Korean urbanite are sex, area of dwelling, degree of information using and degree of stress recognition in case of material orientation, degree of information using in case of environmental orientation, academic career, sex, degree of information using, degree of stress recognition in cases of fate control orientation, number of children, sex, degree of information using in case of equilibrium orientation, sex, degree of stress recognition in case of present orientation and academic career, degree of stress recognition in case of individualistic orientation. Second, value orientation variables that affect overall home management strategy of Korean urbanite are material orientation, environmental orientation, fate control orientation and individualistic orientation. Third, variables that affect overall home management strategy of Korean urbanite are age, academic career, degree of information using, degree of stress recognition, perception level of living relative to others, environmental orientation and fate control orientation and it is shown that degree of information using is domineering variable.

• 대한가정학회지
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• 제48권8호
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• pp.13-26
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• 2010

This study tested the path model with regard to how certain variables (control attribution, demand-control-support of activity, and control strategy) affected the elderly workers' subjective well-being(swb). In the path model, the exogenous variables were internal and external control attribution. We used demand-control-support of activity, and primary and secondary control strategies as mediating variables. The endogenous variable was each elderly worker's swb. Study participants were 205 elders participating in an "education activity". We used descriptive statistical analysis, Pearson's correlation and hierarchical multiple regression to examine data collected from structured interviews with the participants. Path analysis revealed the followings: First, secondary control strategy was the strongest predictor of participants' swb but internal control attribution, demand of activity, and support of activity also positively affected participants' swb. Second, internal control attribution indirectly affected the participants' swb. Finally primary control strategy negatively affected on the participants' swb.

• 한국통신학회논문지
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• 제15권5호
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• pp.384-398
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• 1990

本 硏究는 電壓源 인버어터의 펄스信號를 發生시키기 위한 PWM 方式의 特性 및 長短點을 比較하여 提示하였다. 電壓源 인버어터를 PTR로 設計하여 VSD을 構成한 후 各 PWM 方式으로 誘導電動機를 可變速 運轉시켜 騷音레벨, 線間電壓 및 電流 波形, 電流 高周波 스펙트럼을 測定하였다. 그 結果, Suboptimal PWM 方式은 高周波 影響이 Optimal PWM 方式과 類似한 結果로 良好하게 나타나며 microprocessor 應用이 可能하였고, TP PWM 方式은 3相中 2相만 制御하기 때문에 CPO에 要하는 處理負擔을 줄일 수 있으며 出力電壓을 擴大시킬 수 있는 優秀한 方式임을 알 수 있었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.84-88
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• 1997

A robust position control system for a BLDC motor using new sliding mode control strategy is presented. Using the new variable structure system, reaching phase problem is eliminated and performance is largely improved. The simulation results show the validity of proposed scheme.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2004년도 제3회 정기총회 및 추계학술대회
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• pp.12-17
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• 2004

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.596-600
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• 1987

• Journal of Electrical Engineering and Technology
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• 제1권3호
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• pp.338-342
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• 2006

This paper analyzed the power loss of transformers considering the magnetic component. For this, each winding strategy and the effect of air gap between the ferrite core have been an important variable for optimal parameter calculation. Inductors are very well known design rules to devise, but the performance of the flyback converter as a function of transformer winding strategy has not been fully developed. The transformer analysis tool used was PExpert. The influence of the insulator thickness, effect of the air gap, how the window height and variation of the capacitive value effects the coil and insulator materials are some of parameters that have been analyzed in this work. The parameter analysis is calculated to a high frequency of 48[kHz]. Therefore, the final goal of this paper was to calculate and adjust the parameters according to the method of winding array and air gap minimizing the power loss.