• Communications for Statistical Applications and Methods
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• 제19권2호
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• pp.247-256
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• 2012

In this paper we prove the complete convergence for weighted sums of pairwise negatively quadrant dependent random variables. Some results on identically distributed and negatively associated setting of Liang and Su (1999) are generalized and extended to the pairwise negative quadrant dependence case.

• 충청수학회지
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• 제24권4호
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• pp.783-793
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• 2011

In this paper we introduce the concept of extended linear negative quadrant dependence and obtain some exponential inequalities, complete convergence and almost sure convergence for extended linear negative quadrant dependent random variables.

• 전기학회논문지
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• 제59권2호
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• pp.338-343
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• 2010

Low cost motor drives are being sought for high volume energy efficient home appliances. Key to the realization of such low cost motor drives is to reduce the power electronic converter in terms of its components, particularly the active devices, finding the motor with least complexity for manufacturing and a controller that could extract the desired performance from the machine and converter combination. These and other factors such as self-starting, speed control over a wide range and most of all the crowning aspect of a four quadrant operation with bare minimum number of controllable switch (or switches) remain as formidable challenges for low cost motor drive realization. In this paper, a four quadrant switched reluctance motor (SRM) drive with only one controllable switch is realized by using a two-phase machine. The theory and operation of the proposed four-quadrant SRM drive with the proposed control algorithm for its realization are described. The motor drive is modeled, simulated and analyzed to verify its feasibility for self-starting, speed control and for four quadrant operation and the simulation results are presented. Experimental results confirm the validity of the proposed control algorithm for four quadrant control of the SRM drive. The focus of the paper is mainly directed toward the control algorithm for realizing the four-quadrant operation of the two-phase SRM drive with a single controllable switch converter.

• 한국정밀공학회지
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• 제20권6호
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• pp.20-26
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• 2003

This study proposes the construction of attractor quadrant method for high-precision cutting characteristics evaluation of non-ferrous metals. Also this paper aims to find the optimal cutting conditions of diamond turning machine by measuring surface form and roughness to perform the cutting experiment of non-ferrous metals, which are aluminum, with diamond tool. As well, according to change cutting conditions such as feed rate, using diamond turning machine to Perform cutting Processing, by measuring cutting force and surface roughness and according to cutting conditions the aluminum about cutting properties. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics and attractor quadrant characteristics. In quantitative quadrant feature extraction, 1,309 point in the case of A17075 (one quadrant) and 1,406 point (one quadrant) in the case of brass were proposed on the basis of attractor reconstruction. Proposed attractor quadrant method can be used for high-precision cutting characteristics evaluation of non-ferrous metals.

• 한국콘텐츠학회논문지
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• 제14권5호
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• pp.498-511
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• 2014

본 연구는 컨설팅장학 생활지도 영역 컨설턴트의 역량에 관심을 가지고 생활지도 영역 컨설턴트의 어떤 역량이 가장 중요한지, 그리고 어떤 역량을 우선적으로 강화시켜야 하는지에 대한 우선 순위를 찾는데 목적을 두었다. 조사대상은 17개 시도교육청 생활지도 영역 관련 의뢰인과 컨설턴트로, 온라인 설문조사를 실시하였다. 의뢰인 총 318명, 컨설턴트 총 118명의 자료가 최종 분석자료였으며, 이들의 자료로 IPA 분석을 실시하였다. IPA 분석을 통한 영역별 결과에서, 의뢰인의 경우 2사분면(우선 시정 노력)에 컨설팅장학 능력과 내용전문성이, 4사분면(과잉노력 지양)에는 방법전문성이 포함되었다. 컨설턴트의 경우 1사분면(지속 유지)에 방법전문성이, 2사분면(우선 시정 노력)에 내용전문성이, 그리고 3사분면(낮은 우선 순위)에는 컨설팅장학 능력이 포함되었다. 항목별로 살펴본 결과는 의뢰인의 경우 1사분면(지속 유지)에는 어떤 항목도 포함되지 않았다. 한편 2사분면(우선 시정 노력)에는 10개, 3사분면(낮은 우선 순위)에는 1개가 포함되었으며, 4사분면(과잉노력 지양)에는 4개 항목이 포함되었다. 컨설턴트의 경우 1사분면(지속 유지)에 5개 항목이 2사분면(우선 시정 노력)에는 3개, 3사분면(낮은 우선 순위)에는 3개, 4사분면(과잉노력 지양)에는 4개 항목이 포함되어 의뢰인의 인식과는 다른 형태를 보였다.

• 충청수학회지
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• 제23권4호
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• pp.721-730
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• 2010

In this paper we consider some results on convergence for arrays of rowwise and pairwise negatively quadrant dependent random variables.

• 한국보육지원학회지
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• 제19권5호
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• pp.65-79
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• 2023

Objective: The purpose of this study was to identify the importance and performance of the evaluation indicators of the childcare center evaluation system among childcare center staff and to find ways to improve the evaluation indicators of the childcare center evaluation system. Methods: A survey was conducted among 296 directors and teachers of childcare centers located in Busan and Gyeongnam. The collected data were analyzed using a paired sample t-test and an IPA analysis with SPSS 23.0 and Excel 2010. Results: There was a difference between the perceived importance and performance of childcare staff for the overall evaluation indicators, and significant differences were found in all areas and nine evaluation indicators except for "childcare environment and operation management". According to the IPA analysis, Health and Safety fell into quadrant 1, Staff into quadrant 2, and Child Care Process, Interaction, Child Care Environment, and Operations into quadrant 3. This distribution resulted in 6 indicators in quadrant 1, 4 in quadrant 2, 7 in quadrant 3, and 1 in quadrant 4. Conclusion/Implications: This study provides essential data for exploring ways to enhance the evaluation indicators of the childcare center evaluation system, with the goal of improving the quality of childcare services. Additionally, it offers policy implications.

• 대한수학회논문집
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• 제10권3호
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• pp.707-714
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• 1995

In this note, we extend the concepts of linearly positive quadrant dependence to the random vectors and prove a functional central limit theorem for positively quadrant dependent sequence of $R^d$-valued or separable Hilbert space valued random elements which satisfy a covariance summability condition. This result is an extension of a functional central limit theorem for weakly associated random vectors of Burton et al. to positive quadrant dependence case.

• 대한전기학회논문지
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• 제39권4호
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• pp.349-356
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• 1990

In order to control DC motors for electric cars by chopper system, four quadrant operations - forward powering, forward regenerative braking, reverse powering, reverse regenerative braking - are needed. For the four quadrant operations, the separately - excited DC motors are used in this study. The conversion of each quadrant operation has been obtained by 1) adopting the two phase chopper system with combined output for the armature control, and 2) the single phase chopper system for the field control.

• Journal of applied mathematics & informatics
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• 제5권2호
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• pp.553-564
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• 1998

In this paper we introduce a new concept of more weakly quadrant dependence of hitting times of stochastic processes. This concept is weaker than the more positively quadrant dependence of hitting times of stochastic processes. This concept is weaker than the more positively quadrant dependence and it is closed under some statistical operations of weakly positive quadrant dependence(WPQD) ordering.