• 통합자연과학논문집
• /
• 제13권4호
• /
• pp.147-151
• /
• 2020

In this paper, we propose a method to detect concept drift by applying Convolutional Neural Network (CNN) in a data stream environment. Since the conventional method compares only the final output value of the CNN and detects it as a concept drift if there is a difference, there is a problem in that the actual input value of the data stream reacts sensitively even if there is no significant difference and is incorrectly detected as a concept drift. Therefore, in this paper, in order to reduce such errors, not only the output value of CNN but also the probability vector are used. First, the data entered into the data stream is patterned to learn from the neural network model, and the difference between the output value and probability vector of the current data and the historical data of these learned neural network models is compared to detect the concept drift. The proposed method confirmed that only CNN output values could be used to reduce detection errors compared to how concept drift were detected.

• 컴퓨터교육학회논문지
• /
• 제5권3호
• /
• pp.117-126
• /
• 2002

많은 학생들이 전류에 대한 오개념을 가지고 있고, 이러한 오개념은 전통적인 교육방법에 의해 쉽게 교정되지 않는다. 본 논문은 전류에 대한 오개념 교정을 위한 멀티미디어 타이틀을 개발하여, 학생들에게 적용하여, 오개념 교정의 효과를 분석하였다. 실험 대상은 중학생 32명을 대상으로 하였고, 실험집단은 개발된 멀티미디어 타이틀을 적용하였고, 비교집단은 전통적 강의 수업을 실시하였다. 실험 결과는 SPSS 프로그램을 이용하여 t-검증을 통해 분석하였다. 분석 결과 전류 소모 개념은 수업 방식에 관계없이 비교적 쉽게 교정될 수 있는 오개념임을 보여주고 있다. 전류의 분배 개념은 전통적인 수업 방법으로는 잘 교정되지 않았으며, 멀티미디어 타이틀을 가장 효과적으로 활용될 수 있는 오개념이라고 할 수 있다. 전류의 저항 무관 개념은 가장 적은 학생들이 오개념으로 가지고 있었지만, 전통적인 수업 방식이나 멀티미디어 타이틀을 적용한 학습으로도 교정되기 어렵다는 분석 결과이다.

• 아동학회지
• /
• 제13권2호
• /
• pp.145-160
• /
• 1992

The purpose of this study was to investigate the relationships between children's self-concepts and (1) types of functional family systems. (2) family cohesion and adaptability levels, and (3) the satisfaction of children with their current family systems. The subjects of this study were 347 middle S. E. S. children (168 boys, 179 girls) in grade 6. Analysis of functional family systems was by The Family Adaptability and Cohesion Evaluation Scales III(1985) of the Circuplex Model (Olson et al., 1979). The Self-concept Inventory (Lim Jae Leun, 1987) was used to assess children's self-concepts. The data were analyzed with one-way ANOVA, $Scheff{\acute{e}}$ and Pearson correlation. It was found that there were no differences in children's self-concepts by types of functional systems. There were differences in children's self-concepts by family cohesion and adaptability levels. That is, the higher the level of cohesion and adaptability the more positive the child's self-concept. The more the child was satisfied with his/her current family system, the more positive the child's self-concept. Children whose family systems were at a high level of family cohesion and adaptability were more satisfied with their current family systems.

• 대한기계학회논문집A
• /
• 제31권1호
• /
• pp.43-49
• /
• 2007

A new electric coil design methodology using the notion of topology optimization is developed. The specific design problem in consideration is to find optimal coil configuration that maximizes the Lorentz force under given magnetic field. Topology optimization is usually formulated using the finite element method, but the novel feature of this method is that no such partial differential equation solver is employed during the whole optimization process. The proposed methodology allows the determination of not only coil shape but also the number of coil turns which is not possible to determine by any existing topology optimization concept and to perform single coil strand identification algorithm. The specific applications are made in the design of two-dimensional fine-pattern focusing coils of an optical pickup actuator. In this method, the concept of equivalent magnetizing current is utilized to calculate the Lorentz force, and the optimal coil configuration is obtained without any initial layout. The method is capable of generating the location and shape of turns of coil. To confirm the effectiveness of the proposed method in optical pickup applications, design problems involving multipolar permanent magnets are considered.

• Journal of Power Electronics
• /
• 제8권4호
• /
• pp.332-344
• /
• 2008

High frequency AC (HFAC) power distribution systems delivering power through a high frequency AC link with sinusoidal voltage have the advantages of simple structure and high efficiency. In a multiple module system, where multiple resonant inverters are paralleled to the high frequency AC bus through connection inductors, it is necessary for the output voltage phase angles of the inverters be controlled so that the circulating current among the inverters be minimized. However, the phase angle of the resonant inverters output voltage can not be controlled with conventional phase shift modulation or pulse width modulation. The phase angle is a function of both the phase of the gating signals and the impedance of the resonant tank. In this paper, we proposed a pulse phase modulation (PPM) concept for the resonant inverters, so that the phase angle of the output voltage can be regulated. The PPM can be used to minimize the circulating current between the resonant inverters. The mechanisms of the phase angle control and the PPM were explained. The small signal model of a PPM controlled half-bridge resonant inverter was analyzed. The concept was verified in a half bridge resonant inverter with a series-parallel resonant tank. An HFAC power distribution system with two resonant inverters connected in parallel to a 500kHz, 28V AC bus was presented to demonstrate the applicability of the concept in a high frequency power distribution system.

• International Journal of Human Ecology
• /
• 제7권1호
• /
• pp.131-144
• /
• 2006

This study examined the impact of childhood physical abuse on the self-concept of older adolescents and assessed perceptions of parental relationships as a mediator for consequences of abuse. Sixty-college undergraduates (aged 18-23 yrs.) completed this study. (1) The Self-Description Questionnaires, a multidimensional measure of self-concept, (2) the parent scales of the inventory parent and Peer Attachment, a measure of perceived parental support, and (3) the Assessing Environments, a retrospective report of family environment and parenting practices. Analyses, controlling for SES and education, showed that a history of physical abuse was a strong predictive of adolescence current self-concept. Further analyses would lend support to a mediation model, suggesting that physical abuse had a negative impact on self-concept through its negative effect on parent-child relationships.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.171-173
• /
• 2001

Conventional potential concept does not allow different currents before and after the electric load. Experimental examples in case of bioloads show a lot of different currents before and after the bioload, which means that the true potential concept is not the conventional concept from Coulomb attraction energy but the new concept from Gibb's free energy. Gibb's free energy is a kind of potential heat energies and also they are rotating electromagnetic waves. We might think that electric current is not a flow of electrons but a flow of rotating electromagnetic waves, which induces electrons' vibrations. A new measuring method for integral electrical power is suggested for the new Gibb's free energy concept.

• 한국치위생학회지
• /
• 제18권3호
• /
• pp.399-410
• /
• 2018

Objectives: The purpose of this study was to examine the current status of the relationship between clinical practice stress, satisfaction and self-concept of dental hygiene department students in order to effectively implement the clinical practice, which is a necessary course for professional dental hygienists. Methods: The subjects in this study were 299 dental hygiene department students who participated in clinical practice. The survey was conducted from November 1, 2017 to December 31, using self-filling questionnaire (INJE 2017-08-004-002). Statistical analysis was conducted to identify the clinical practice characteristics, clinical practice stress, satisfaction and self-concept and the results according to clinical practice characteristics were compared through t-test and ANOVA. The regression analysis was conducted to identify the effects on self concept. Results: Clinical practice stress, satisfaction and self concept were identified to be significant(p<0.01). Multiple regression analysis results of the factors affecting self concept of study subjects showed that self concept was statistically significant in grade, education programs and satisfaction. Conclusions: Self-concept, clinical practice stress and satisfaction were significantly correlated. In order to raise the quality of clinical practice and to become a professional dental hygienist, it is necessary to continue research on the measures to improve the stress management and satisfaction in clinical practice for establishing self-concept.

• 기술혁신학회지
• /
• 제6권3호
• /
• pp.306-327
• /
• 2003

The importance of technology assessment(TA) is increasingly emphasized, however, the question of what is TA is ambiguous yet. This article traces the concept of TA, and tries to identify the its meaning and current issues. It argues that the ambiguity of TA concept is not tragedy, but blessing in its growth. We came to know that one should consider for a successful TA some issues : institutional conditions, methodology, functions and timeliness. And they should also be considered in the TA-building process of Korea which is now on.

• 대한수학교육학회지:수학교육학연구
• /
• 제20권4호
• /
• pp.529-546
• /
• 2010

이 연구의 목적은 닮음 개념의 변천 과정에 대한 수학사 고찰을 바탕으로, 현재 수학 교과서에 나타난 닮음 정의를 분석하고 비판하는 것이다. 우선, 피타고라스학파의 닮음 정의, Euclid ${\ll}$원론${\gg}$의 닮음 정의, Clairaut의 ${\ll}$기하학원론${\gg}$의 닮음 정의, Birkhoff와 Beatly의 ${\ll}$기초기하학${\gg}$, SMSG의 ${\ll}$기하학${\gg}$의 닮음 정의를 분석하고, 현재 수학 교과서에 제시된 닮음 정의를 분석하였다. 수학사 고찰 결과를 바탕으로 교과서의 닮음 정의를 세 가지 측면에서 비판적으로 논의하고, 확인된 문제점에 대한 교육적 제언을 하였다.