• 치위생과학회지
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• 제17권3호
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• pp.257-266
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• 2017

This study investigated factors affecting the subjective experience of oral symptoms among 2,285 elementary school students in the fourth and sixth grades using the Korean survey on the Health of Youth and Children in 2010. After conducting chi-square and Mann-Whitney U tests, we performed multiple logistic regression analysis to determine the factors affecting children's experience of oral symptoms. We found that the factors most frequently associated with the subjective experience of more oral symptoms were lower tooth brushing frequency, greater intake of foods that cause dental caries, higher stress levels, and lower levels of support from friends. In conclusion, determinants of children's oral health, such as children's oral health behaviors and psychological factors must be considered in a multifaceted approach to developing programs to promote oral health among children.

• 아동학회지
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• 제26권6호
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• pp.1-15
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• 2005

The purposes of this study were to assess children's emotional competence, to examine whether there was a difference in children's emotional competence according to their gender, and to investigate the relationship between children's emotional competence and their play behavior. The subjects of this study were 104 four-year-old children(56 boys, 48 girls). Collected data were analyzed by frequency, percentage, means, standard deviation and Pearson's correlation. The results were as follows : First, there was meaningful correlation among the emotional competence measured by teacher, the understanding and expression of emotion and the emotional regulation measured by mother. Second, there was difference in children's emotional competence according to gender. Specifically, girls showed better competence in the socio-behavioral emotional competence and the understanding and expression of emotion than boys. Third, the dramatic play and the group play had some meaningful correlation with the emotional competence measured by teacher and the understanding and expression of emotion measured by mother.

• Agribusiness and Information Management
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• 제1권1호
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• pp.3-18
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• 2009

This research aims to examine consumers' general types of information search and their unsatisfactory factors in purchasing agricultural products on electronic commerce and analyze consumers' behavioral characteristics. As study subjects, 802 consumers who have visited the home pages of 14 households or companies, whose home pages are actively managed, were sampled. As a research tool, pop-up post and e-mail were used as research tools and questionnaires were asked three times. The date on research result were analyzed using SPSS 13 statistics package in terms of frequency, percentage, descriptive statistics, one-way ANOVA and correlation analysis.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권3호
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• pp.122-129
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• 2001

Exact simulation of conducted EMI in switched mode power supplies is proposed. In order to achieve exact simulation, PSPICE active component ABM model and modified transformer model are proposed. Each model parameter is extracted from measurements and data-books. PSPICE simulation results with high frequency PCB pattern model are accordant with EMI measurements for a 50[W] isolated flyback converter. EMI relations of each component and EMI patterns are analyzed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1876-1878
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• 1998

For an analysis and simulation of the conducted EMI of switching converters, an accurate simulation model for MOSFET is needed. This paper presents a new modeling approach, which incorporates DC output characteristics and AC dynamics especially the parasitic capacitances. It uses Pspice ABM(Analog Behavioral Model) and the MOSFET parameters can be obtained from the Data sheet in the frequency range of interest for EMI analysis. The model verified with an experimental setup and the EMI for a test converter is analyzed with respect to the MOSFET switching waveforms.

• 대한인간공학회지
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• 제24권1호
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• pp.19-26
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• 2005

Mobile internet access using such devices as PDAs and cellular phones becomes popular as mobile technologies grow. However, the characteristics of small screen devices such as small screen size and pen-based input cause many usability problems. In this study, a human factors experiment was conducted to identify the factors affecting the usability of information search on a PDA. Factors manipulated in the experiment included use of wheel equipment, scroll dimension, and screen orientation. Task completion time, error frequency, and subjective satisfaction level were measured. In addition, various users' behavioral patterns such as scanning routes and mainly used scrolling methods were analyzed. Scroll dimension has a significant effect on task completion time. Scroll equipment and screen orientation affect subjective satisfaction level. The results could be applied to designing information structure of web sites for mobile use by providing vertical scroll and using external scroll equipments.

• 아동학회지
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• 제30권3호
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• pp.55-69
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• 2009

The purpose of this study was to describe preschoolers' perceptions of fear from their own perspective. Qualitative data from 213 preschoolers 4 to 6 years of age were obtained by semi-structured interviews. The fear inventory was analyzed by content analysis and frequency. The most common fears of preschoolers in this study were fear of ferocious animals and imaginary figures, such as tigers, lions, snakes, spirits and ghosts. Fear of ghosts was the primary fear of both boys and girls. Results showed that most fears were caused by disgust-related visual images. Worry about injury and pain was another common pathway to fear. At-risk preschoolers scored significantly higher than normal preschoolers on fears of criticism and getting an injection.

• 한국주거학회논문집
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• 제15권1호
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• pp.75-84
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• 2004

As the advent of an aging society, housing for the elderly has been of greater concern. Since the majority of the elderly prefers to live in their own familiar houses rather than moving to new ones, this study is concerned with the ways of the effective use and maintenance of exiting houses from the viewpoint of their independent living. The data was analyzed with frequency, percentage, mean, correlation, and multiple regression using the SPSS 10.0 for Windows. The findings from the study are: The general satisfaction rate of Interior Design Affordance(IDA) was-evaluated about the average. Among the items of IDA, behavioral facilitation was found most satisfactory, and perceptual maintenance, physilogical maintenance, and social facilitation were followed in satisfaction level. Although there had been many elements of serious safety dangers, no home modification was made in the elderly households who live alone or/with spouse.

• ETRI Journal
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• 제30권4호
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• pp.535-545
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• 2008

This paper introduces a systematic top-down and bottom-up design methodology to assist the designer in the implementation of continuous-time (CT) cascade sigma-delta (${\Sigma}{\Delta}$) modulators. The salient features of this methodology are (a) flexible behavioral modeling for optimum accuracy-efficiency trade-offs at different stages of the top-down synthesis process, (b) direct synthesis in the continuous-time domain for minimum circuit complexity and sensitivity, (c) mixed knowledge-based and optimization-based architectural exploration and specification transmission for enhanced circuit performance, and (d) use of Pareto-optimal fronts of building blocks to reduce re-design iterations. The applicability of this methodology will be illustrated via the design of a 12-bit 20 MHz CT ${\Sigma}{\Delta}$ modulator in a 1.2 V 130 nm CMOS technology.

• 전기학회논문지
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• 제61권5호
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• pp.721-725
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• 2012

In this paper, a novel analysis on the nonlinear response of a power amplifier (PA) with the intermodulation distortion (IMD) asymmetry is proposed based on the mutislice behavioral model. The coefficients of the odd-order and even-order polynomial of that model are represented with the PA practical circuit parameters such as intercept points, gain and amplitudes of excitation inputs. We also develop the analytic expressions to distinguish baseband frequency effect from second harmonic effect on the IMD asymmetry. We also validate the derived analytic expressions through measurements.