• 한국치위생학회지
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• 제12권6호
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• pp.1071-1081
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• 2012

Objectives : This study were to find out differences in mother's oral health knowledge and oral health care behaviors and to find out factors that affected mothers' oral health care behavior for their young children. Methods : The survey was carried out with questionnaire about personal factor, cognitive factor, psychological factor and behavioral factor to 227 mothers. They had children from 3 to 5 years. The collected data was analyzed by SPSS WIN 12.0. Results : There were statistically significant differences in oral health knowledges as mother's educational background, importance of oral health, experience of oral health education, and oral health locus of control. There were statistically significant differences in mother's oral health care behaviors as mother's job, interest of oral health, importance of oral health, experience of oral health education, and oral health locus of control. And mother' oral health care behavior for herself, interest of oral health, and oral health locus of control were found as important variables in mothers's oral health care behavior for their children. Conclusions : Mother's oral health care behavior for herself was the powerful factor that affected mother's oral health care behavior for her children.

• 대한통합의학회지
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• 제8권1호
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• pp.159-168
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• 2020

Purpose : To provide data on exercise prescription for obesity management and prevention of cardiovascular disease in girl's high school and to prepare basic data for more effective exercise program for lifestyle improvement and prevention of lifestyle-related diseases. This study examines the effects on brain nerve growth factor and inflammatory factors, and the relationship between obesity factor and brain neuron cell production factor and inflammatory factor changes by complex exercise. Methods : The subjects of the study were obese students with a body fat percentage of 30 % or higher after obtaining body fat percentage of high school girls in C-city. Among them, 20 students who wanted to participate in the program of this study and did not participate in special exercise and diet therapy within the last 6 months were radio-sampled into groups of exercise group and control group, but attendance rate was low and The final exercise group (9) and control group (9) were measured, except for one student who did not respond. Results : Analysis of the range of variation in body composition, BMI, lean body mass, and the interaction between the groups showed significant differences (p<.05). TC, TG, HDL-C, and LDL-C as variables of blood lipids, TC and TG were not significantly different and TG was significantly different (p<.05) in interactions. HDL-C showed a significant difference (p<.01) in interactions, an increase in exercise group, and a significant decrease in control group (p<.05). There was a significant difference (p<.05) in BDNF interaction, an increase in the exercise group and a decrease in the control group, but no significant difference. NGF tended to increase in both exercise and control groups. IL-6 had a significant difference in timing (p<.05) and significantly decreased (p<.01) in the exercise group, and TNF-α interacted with timing (p<.05), and a significant increase in the control group. Conclusion : This study confirmed 12-week compound exercise program was effective in increasing the expression of basal fitness or CNS factor, but not enough to actually improve brain function. Fat mass and obesity are also affecting vascular inflammatory factors.

• 대한의생명과학회지
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• 제11권1호
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• pp.23-29
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• 2005

Molecular imaging with targeted contrast agents enables tissues to be distinguished by detecting specific cell-surface receptors. In the present study, a ligand-targeted acoustic nanoparticle system is used to identify angioplasty-induced expression of tissue factor by smooth muscle cell within carotid arteries. Pig carotid arteries were overstretched with balloon catheters, treated with tissue factor-targeted or a control nanoparticle system, and imaged with intravascular ultrasound before and after treatment. Tissue factor-targeted emulsion bound and increased the echogenicity and gray-scale levels of overstretched smooth muscle cell within the tunica media, versus no change in contralateral control arteries. Expression of stretch-induced tissue factor in carotid artery media was confirmed by immunohistochemistry. The potential for abnormal thrombogenicity of balloon-injured arteries, as reflected by smooth muscle expression of tissue factor, was imaged using a novel, targeted, nanoparticulate ultrasonic contrast agent.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권2호
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• pp.65-72
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• 2004

Switching power supply systems are widely used in many industrial fields. Power factor correction (PFC) circuits have a tendency to be applied in new power supply designs. The input active power factor correction (APFC) circuits can be implemented in either the two-stage approach or the single-stage approach. The two-stage approach can be classified into boost type PFC circuit and dc/dc converter. The power factor correction circuit with a boost converter used as an input power source is studied in this paper. In a boost power factor correction circuit there are two feedback control loops, which are a current feedback loop and a voltage feedback loop. In this paper, the regulation performance of output voltage and compensator to improve the transient response presented at the continuous conduction mode (CCM) of the boost PFC circuit is analyzed. The validity of designed boost PFC circuit is confirmed by MATLAB simulation and experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.163-167
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• 2000

This paper presents the digital control of single-phase power factor correction(PFC) converter which has the variable gain according to the condition of inner control loop error. Generally the gain of inner current control loop in single-stage PFC converter has a constant magnitude. This has a bad influence on the power factor because current loop doesn't operate smoothly in the condition that input voltage is low In particular a digital controller has more time delay than an analog controller and degrades This drops the phase margin of the total digital PFC system,. It causes the problem that the gain of current control loop isn't increased enough. In addition the oscillation happens in the peak value of the input voltage open loop PFC system gain changes according to ac input voltage. These aspects make the design of the digital PFC controller difficult The digital PFC controller presented in this paper has a variable gain of current control loop according to input voltage. The 1kW converter was used to verify the efficiency of the digital PFC controller.

• 아동학회지
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• 제19권2호
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• pp.115-132
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• 1998

The present study investigated the construction of the moral concepts of 3-, 4-, and 5- year old Korean children. Instruments were the Maternal Behavior Research Instrument by Schaefer for mother and feather nurturing attitudes, and the Domain Distinctiveness Model for children's moral judgments. Maternal and teacher attitudes were categorized by the affection-rejection factor consisting of affection-affection, affection-rejection, rejection-affection, and rejection-rejection dimensions, and by the permissive, -control factor consisting of permissive-permissive, permissive-control, control-permissive, and control-control dimension. Children's data were collected with an individualized interview in which children were asked to judge moral and social conventional transgression events. 30 children were assigned to each of the maternal/teacher attitude dimensions; thus, there were 120 children for each factor. Results showed that (1) the affection-affection cohort was must strongly related to moral rules using both the seriousness criterion and deserved punishment criterion, and (2) the permissive-permissive cohort was most strongly related to reasoning and action. However, this cohort did not break out of children's structural limitation (limited responses to the intangible).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.635-636
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• 2006

A pulse with modulation(PWM) that keeps a constant angle of dwell and adjust duty ratio is a good method to control a speed of SRM. And a method of one pulse control is proper a operation on range of high speed in SRM for a good energy efficiency. Because PWM method is more safety than one pulse method, conversion of those is best choice according the speed range. So, some algorithm is need for smooth conversion of the mode of control. This paper presents a factor of conversion that proper the conversion of control mode between PWM and one pulse method This factor is from estimation of torque and proper at the variable range of conversion and show the better conversion characteristic than constant factor of conversion.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.234-236
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• 2003

In this paper, a new control scheme of Class-E inverter for reducing the crest factor of electronic ballasts for fluorescent lamps using Pulse-Frequency-Modulation (PFM) is introduced The lifetime of the lamps is guaranteed by decreasing the lamp crest factor and voltage stress of the switch is significantly decreased by a new scheme although conventional Class-E inverter is used in this paper The proposed PFM control scheme doesn't used any auxiliary circuit. The proposed control strategy is executed by feeding back the input current. and the Zero-Voltage-Switching (ZVS) is ensured by operating beyond resonant frequency. Therefore, the control principles of proposed method are explained in detail and its validity is verified through several simulated results.

• 전력전자학회논문지
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• 제21권2호
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• pp.144-149
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• 2016

This paper presents a power control method of high-speed single-phase BLDC motor. Most electric appliances require a power factor corrector (PFC) to mitigate grid current harmonics. However, the reactive components and power semiconductors in the PFC increase system cost and dimension. In this paper, a new motor drive system for a high-speed single-phase BLDC motor is proposed, which can decrease grid current harmonics without PFC by directly manipulating motor power and eliminating bulky electrolytic dc-link capacitor. Given that the proposed motor power control method does not require motor current controller, no current sensor is necessary. Moreover, the proposed algorithms can be easily implemented using a low-cost micro-controller. The effectiveness of the proposed power control method is verified by experiments.

• Journal of Power Electronics
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• 제14권4호
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• pp.712-721
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• 2014

This paper introduces a simple grid-voltage-sensorless control scheme for single-phase power factor correction (PFC) boost converters. The grid voltage waveform is obtained based on the dc output voltage, the switching duty ratio, and a phase-lead compensator. In addition, the duty ratio feedback is utilized to obtain the unity input power factor and the zero harmonic current. The proposed control scheme is designed and mathematically analyzed based on a small-signal model of PFC boost converters. To verify the effectiveness of the proposed control scheme, several simulations and experiments are carried out in two applications: an industrial power system with a 60 Hz grid frequency and a commercial aircraft application with a 400 Hz grid frequency.