• 아동학회지
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• 제13권2호
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• pp.129-144
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• 1992

The purpose of this study was to investigate the current status of family child care. The status of family child care was explored in terms of general characteristics, program quality, and child behavior. The subjects were 17 family child care and their 102 children and 60 parents. Harms & Clifford's (1989) FDCRS(Family Day Care Rating Scale) was used to measure program quality. Child behavior was recorded by time sampling in two 30 min observations during the free play session in each facility. A questionnaire for caregiver and parents was used to investigate general characteristics. The data were analysed by frequency, percentage, and Pearson's r. Results showed that (1) a wide range of variable accounted for the general characteristics of family child care, (2) the level of program quality as rated by the FDCRS was below mid-point, (3) children engaged in solitary behavior much more than in peer interactions or caregiver-child interactions.

• 대한가정학회지
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• 제35권2호
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• pp.385-399
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• 1997

The purpose of this study was to investigate the relationship between the quality of caregiver's behaviors and children's social behaviors. the quality of caregiver's behaviors were observed during indoor free-play time in the 8 classes at 7 child care centers. Forty children were selected from two classes of high quality caregivers and 2 of low quality caregivers based on the quality of caregiver's behaviors. Children's social behaviors were measured in terms of social competence, social maladjustment, and social interaction. results of the study were as follows: First, children of high quality caregivers were more socially competent than of low quality caregivers. second, there were no significant differences in social maladjustemnt according to the quality of caregiver's behavior. Third, children of high quality caregivers showed more positive and dependent interaction with caregivers high quality caregivers showed more positive and depedndent interaction with caregivers than of low quality teachers. Also, children of high quality caregivers engaged less in aimless behavior and negative interaction with peers than of low quality caregivers.

• 대한가정학회지
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• 제44권4호
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• pp.159-173
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• 2006

The purpose of this study was to investigate the seating style of children between Korea and USA viewed from activity analysis in child-care centers. Observation and depth-interview method were used for data collection. Ninety-eight children aged from 38 to almost 62 months were observed for five minutes three times during an indoor free play period in Korea and USA in 2003 and 2004. The results of the research were as follows. There were significant differences between the postures of Korean and American children. Korean children maintained floor-seating postures longer than chair-seating and standing postures. The factors such as sex, age and physical environment influenced the children's seating style, while playing-type influenced their posture. This study will contribute to our understanding of the physical environment and children's seating style according to culture.

• 대한음성학회지:말소리
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• 제67호
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• pp.61-77
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• 2008

The purpose of this study is to blow the characteristics of disfluency in childhood. The subjects were 144 normal children at the age of between 3 to 8 years who lived in Seoul. All the subjects provided spontaneous conversational speech samples during free-play interactions with their friends. We investigated the patterns and the frequency of disfluency and its relevance with subject's age, speaking rate and MLU(mean length of utterance). The results of this study can be summarized as follows. (1) There was no difference in the frequency of disfluency with the speaker's age or speaking rate. (2) Interjection was the most frequently occurring pattern of disfluency. (3) Prolongation, revision, interjection increased with age while part-word repetition, single-syllable word repetition, multi-syllable word repetition decreased gradually. (4) A significant effect of MLU on the frequency of disfluencies were demonstrated. The regression analysis has shown that more disfluencies occurred in utterances of children whose MLU is longer.

• The Journal of the Acoustical Society of Korea
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• 제19권1E호
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• pp.38-42
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• 2000

In this paper we studied the reduced subjective timbre space of time-varying tones as well as steady state tones. 45 modified test tones were constructed from the original violin tone in consideration of 4 physical factors: spectrum envelope, inharmonicity, time-varying spectrum and time reversal. The semantic differential (SD) method was used in the listening test. According to the factor analysis, the adjectives can be factorized into 4 groups. The first factor is characterized by the adjectives, 'free', 'broad', 'deep', 'rich', 'strong' and 'reverberant', the second by 'tenor', 'clear', 'bright', 'light' and 'sharp', the third by 'easy', 'smooth', and 'solid', the fourth by 'warm' and 'full'. The first factor, 'richness', seems to be dependent upon the time-varying characteristic of a tone. The second factor, 'sharpness', is shown to play an important role in a time-varying tone as well as in a steady state tone.

• Elastomers and Composites
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• 제50권1호
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• pp.13-17
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• 2015

A study of the effects of MWCNT as a nucleating agent on the formation reactions of the rigid polyurethane foams (RPUFs) was carried out. Sample PUFs, formulated with grease-type master batch of MWCNT/surfactant, were fabricated by free-rising method. Temperature changes with time during foaming process were measured using a digital thermometer. RPUF foaming process was observed to undergo 2-step processes with temperature inflection around 60 sec after the start of reaction, and then reached slowly the max. temperature. While the max. temperature of neat PUF was measured as ca. $120^{\circ}C$, that of the samples with MWCNT were as higher value as ca. $130^{\circ}C$, and, even the time to reach that temperature was reduced by about 15 sec. Average cell size of PUF samples decreased from 185.1 for the neat PUF to $162.9{\mu}m$ for the sample of 0.01 phr of MWCNT. As the result, it was considered that MWCNT in RPUF foaming process could play a roll both as a nucleating agent and as a catalyst.

• Toxicological Research
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• 제20권1호
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• pp.31-36
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• 2004

Against environmental stress, ceruloplasmin which is a plasma protein, are believed to play central roles in antioxidant- or peroxidase-activity in blood stream to remove free radicals, which may be caused by exposing of $\gamma$-irradiation. In human U-937 cells exposed to $\gamma$-irradiation, the levels of mRNA in ceruloplasmin gene were measured on 0, 4, 12, 24 hr after exposing by using comparative RT-PCR (Reverse transcriptase-polymerase chain reaction) which was achieved to compare with house keeping genes such as $\beta$-actin and hprt. After $\gamma$-irradiation of 100 rads or 200 rads, the total quantities of RNA were increased as dose and time dependent manner. On the contrary, the variation of mRNA expression in ceruloplasmin was not found until 4 hr after irradiation. After 12 hr and 24 hr of irradiation, the levels of mRNA in ceruloplasmin were significantly increased as dose and time dependent manner than un-exposed cells.

• Biomolecules & Therapeutics
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• 제21권6호
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• pp.411-422
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• 2013

G-protein-coupled receptors (GPCR) are the largest superfamily of receptors responsible for signaling between cells and tissues, and because they play important physiological roles in homeostasis, they are major drug targets. New technologies have been developed for the identification of new ligands, new GPCR functions, and for drug discovery purposes. In particular, intercellular lipid mediators, such as, lysophosphatidic acid and sphingosine 1-phosphate have attracted much attention for drug discovery and this has resulted in the development of fingolimod (FTY-720) and AM095. The discovery of new intercellular lipid mediators and their GPCRs are discussed from the perspective of drug development. Lipid GPCRs for lysophospholipids, including lysophosphatidylserine, lysophosphatidylinositol, lysophosphatidylcholine, free fatty acids, fatty acid derivatives, and other lipid mediators are reviewed.

• 아동학회지
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• 제26권6호
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• pp.173-187
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• 2005

This study examined relations between infants' strategies for emotional regulation and maternal responsiveness. Fifty 24-month-olds were observed for six kinds of emotional regulation strategy during four negative emotion-eliciting tasks; their mothers were observed for five styles of maternal responsiveness during toy-centered free play. Infants used different strategies according to the kinds of negative emotioneliciting tasks; their strategies correlated with maternal responsive styles. In the anger-eliciting tasks, infants used "distraction" and "self soothing." In the fear-eliciting tasks, they used "avoidance" and "problem solving." Infants who received more negative feedback from their mothers used the "irritation" strategy. Infants who got received more positive feedback from their mother used the "getting reference" strategy.

• 아동학회지
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• 제28권5호
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• pp.109-126
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• 2007

A sample of 322 18-month-old infants and their mothers were assessed longitudinally at 24 and 30 months. Maternal utterances and styles of linguistic interaction were measured during a 10 minute free play session. Mothers completed a vocabulary checklist for infants. Longitudinal data were analyzed by multilevel modeling. Results indicated that vocabulary increased with age of infants and the growth rate was highly predictable by the size of vocabulary at 18 months. The growth rate was strongly influenced by maternal questioning and feedback. The effect of the maternal linguistic input was constant with age. Gender differences in size of vocabulary did not vary systematically with age.