• Proceedings of the KSME Conference
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• 2004.04a
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• pp.840-845
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• 2004

In many applications, piezoelectric motor has been used in the areas where excellent controllability, fine position resolution are required or magnetic field noise should be eliminated. However the piezoelectric motor has two major demerits. One is difficulty in maintaining vibration amplitude constantly with temperature rise and wear, and the other is heat generation induced by dielectric and mechanical loss. In this thesis, piezoelectric motor to overcome these problems is proposed. And proposed piezoelectric motor is operated using momentum exchange between bimorph and rotor. To maximize steady state velocity and static torque of proposed motor, the guideline is established using two bimorph models. Then the guideline is partially proved by comparison between simulation and experiment. There was no heat generation in the few hours of experiments.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1337-1341
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• 2005

Purpose : This study aimed to evaluate the usefulness of Korean Infant Development Screening Test in predicting delayed development in premature infants. Methods : A total of 74 children with histories of prematurity, who visited the pediatric neurology clinic of Korean University Ansan Hospital from August, 2002 to July, 2004, were examined, using the Korean Infant Development Screening Test. They were divided into two groups; a normal group and a patient(neurologically compromised) group. Results : At 7 months of conceptional age, the normal and patient groups differed significantly in the fine motor, cognitive-adaptive sections. At 12 months of conceptional age both group, differed significantly in the gross motor, fine motor, personal-social, language and cognitive-adaptive sections. At 18-24 months, the group, differed significantly in gross motor, fine motor, personal-social, language and cognitive-adaptive sections. Conclusion : The Korean Developmental Screening Test was useful in predicting developmental delay in premature infants.

• Child Health Nursing Research
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• v.13 no.1
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• pp.51-57
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• 2007

Purpose: The purpose of this study was to look for physical growth and developmental retardation of the disabled children in registered educational institutions. Method: The participants in this study were 103 children. The data was collected from January to September 2006. Body weight, height and head circumference were measured and the Denver II developmental screening tool was used to measure personal-social development. Results: For 40.8% of the children body weight was less than the average for Korean children of the same age, for 49.5% height was lower than average and for 44.7% head circumference was lower. For 84.5% of the children there was a delay in personal-social development, for 87.4% a delay in fine motor-adaptive development, for 80.6% a delay in speech development and for 81.6% a delay in gross motor development. Conclusion: Based on the findings of this study, it is necessary to develop an individual developmental programs for these children based on their growth and development status.

• Korean Journal of Child Studies
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• v.37 no.3
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• pp.83-93
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• 2016

Objective: This study examined that general characteristics such as gender, age, period of stay at an institution, size of facility, and temperament and attachment affect young children's development under institutional care. Methods: A total of 94 young children (ages 2-4years), who live in 32 institutions in Seoul were assessed on their development using the Korean-Age & Stage Questionnaire. Pearson productmoment correlation analysis, and multiple regression analyses were used for data analysis. Results: The major findings of this study were as follows: first, a longer period of stay at an institution had more positive effects on the development of communication. Facilities with more than 60 children had lower communication, gross motor, and fine motor development compared to facilities with less than 60 children. Second, social temperament had positive effects on communication, problem solving, and personal-social development. Emotional temperament had no effects on all development areas. Third, attachment had positive effects on all development areas. Lastly, social temperament and attachment had interactive effects on communication, gross motor, problem solving, and personal-social development. Conclusion: These results imply that caretakers in institutions should give developmental mediation services for considering temperament and facilitation of attachment.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.158-161
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• 2005

For low power motor control, there are increasing demands for compactness, cost effective and built in many functions. Hence Intelligent Power Module(IPM) is considered as an important technology in inverter-driven motor applications. Regarding BID-IPM(Built In DC/DC converter, Intelligent Power Module) newly developed to integrate NPT-IGBT, HVIC and Flyback converter in a compact package, this paper discussed design of BID-IPM and presented the experimental results by using signal source board and equivalent load test board.

• Korean Journal of Child Studies
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• v.27 no.4
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• pp.39-53
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• 2006

The Korean version of the Child Development Inventory (K-CDI) is a developmental screening test for children functioning in the one-six year range. Based on parent-report, the inventory assesses child developmental functioning in the areas of social, self-help, gross motor, fine motor, expressive language, language comprehension, letter and number skills, general development, and various symptoms and behavior problems. Participants were recruited from childcare centers and private groups and finally 1,143 children and their mothers from 4 locations nationwide participated in this study. Through analysis of item response rate of 270 items in 9 areas, new norm was formed. Reliability determined by internal consistency were relatively high (Cronbach ${\alpha}=.95$). Intercorrelations among sub-scales (range: .49-.96) indicated the construct validity, and the correlation between K-CDI and other screening tests supported the concurrent validity.

• Journal of Korean Academy of Nursing
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• v.13 no.3
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• pp.51-60
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• 1983

Currently changing trends of child health care is demand total health assessment of child including growth and development. This study concentrates on the growth & developmental status of low birth weight infant for help their growth & development. Thus it can be provide a direction for scientific health education and counseling materials by investigating factor of growth & development. The subjects for this study were made up of 40 low birth weight infant who attended the well baby clinic of E university Hospital. The study method used was a questionnaire ＆ anthropometric assessment and DDST for normative data of development. The period for data collection was from July 1st to August 31th, 1982. Analysis of the data was done using percentages, $\chi$$^2$-test Stepwise Multiple Regression. The results of study were as follows. 1. The mean weight of birth was 2,068gm and mean of gestational period was 35.65 weeks. 2. The age at which weight ; 32.5%, head circumference : 67,5% chest circumference : 55.0%, height : 50. 0％ was normal range of physical growth. 3. The reverse age at which social development ; 87.5%, fine motor & adaptive development ; 70.0%, gross motor development ; 72.5% of children Passed by DDST to determine of normal range of development. 4. In the among variables, it was found that the infant who were the higher emotional & verbal response of mother and stimulus environment was the more normal range of weight & development than who was not. 5. The stepwise Multiple Regression between developmental status and predictors-birth order, weight at birth, sex, antenatal care, gestational period-are accounts for 34.1%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.104-107
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• 2005

Recently, according to the development of semiconductor industry, needed to high-integration and high-functionality. These changes are required for silicon wafer of large scale diameter and precision of TTV (Total Thickness variation). So, in this research, suggest that the method of monitoring system is using motor current. This method is needed for observation of silicon wafer grinding process. Motor current sensor is consisted of hall sensor. Hall sensor is known to catching of change of current. Received original signal is converted to the diginal, then, it is calculated RMS values, and then, it is analysed in computer. Generally, the change of force is relative to the change of current, So this reason, in this research tried to monitoring of motor current change, and then, it will be applied to analysis for silicon wafer grinding process. using motor current sensor.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.43-50
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• 2006

Recently, with rapid development of semiconductor and flat panel display, the manufacturing equipments are required to have large travel range, high productivity, and high accuracy. In this paper, an ultra precision decoupled dual servo (DDS) system is proposed to meet these requirements. And a control scheme for the DDS is studied. The proposed DDS consists of a $XY{\Theta}$ fine stage for handling work-pieces precisely and a XY coarse stage for large travel range. The fine stage consists of four voice coil motors (VCM) and air bearing guides. The coarse stage consists of linear motors and air bearing guides. The DDS is mechanically decoupled between coarse stage and fine stage. Therefore, both stages must be controlled independently and the performance of the DDS is mainly determined by the fine stage. For high performance tracking, the controller of fine stage consists of time delay control (TDC) and perturbation observer while the controller of coarse stage is TDC alone. With these individual controllers, two kinds of dual-servo control strategies are suggested: master-slave type and parallel type. By simulations and experiments, the performances of two dual-servo control strategies are compared.

• The Journal of Korean Academy of Sensory Integration
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• v.17 no.2
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• pp.18-30
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• 2019

Objective : The purpose of this study was to investigate the effect of Ayres's sensory integration (ASI) intervention on the sensory processing ability and motor development in children with Developmental Delay. Methods : 9 children in the experimental group and 8 children in the control group participated in this study for Developmental Delay children aged 3-5 years. For research tool, the Short Sensory Profile (SSP), Peabody Developmental Motor Scale-2 (PDMS-2) are used. In the experimental group, individual sensory integration therapy according to principle of ASI was performed for twice a week, 40 minutes, and 16 times for 8 weeks. Methods for the data analysis included Mann Whitney U test, Chi-square test, Wilcoxon's signed rank test, Cohen's d test of SPSS 24.0. Results : In the ASI Intervention group, the sensory processing ability showed statistically significant difference in total score, movement sensitivity, auditory filtering and low energy/weak compared to the control group without ASI intervention (p<.05). In the ASI Intervention group, the motor development showed statistically significant difference in Gross Motor Quotient, Fine Motor Quotient and Total Motor Quotient compared to the control group without ASI intervention (p<.05). Conclusions : In this study, ASI intervention had a positive effect on the sensory processing and motor development in children with Developmental Delay.