• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.1
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• pp.10-17
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• 2002

Due to the development of information communication field, the interest of the SMPS(Switched Mode Power Supply) is increased. The size and weight of SMPS are decided by inductor, capacitor and transformer. Thus, the low loss converter which is operated in high speed switching is required. The resonant FB DC-DC converter is able to operate in high speed switching and apply to high power field because the switching loss is low. In this thesis, it is proposed to control strategy for constant output power of resonant FB DC-DC converter in variable input voltage. The proposed control system is a digital I-PD type control and apply to phase-shift resonant type controller. The output voltage tracks reference without steady state error in variable input voltage. The validity of proposed control strategy is verified from results of simulation and experiment.

• Journal of Ocean Engineering and Technology
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• v.19 no.1 s.62
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• pp.95-99
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• 2005

This paper presents the optimum design of cylindrical shell under external pressure loading. Two kinds of material, Al7075-T6, Ti-6Al-4V, are considered. For each material, the design variable is a thickness of the unstiffened parallel middle body shell, and the state variable, constraint, is hoop stress and the object .function is total weight of the cylindrical shell. Optimization is performed by conventional FE Program, ANSYS. In addition, buckling analysis is performed for the middle body of the cylindrical shell. Finally, we calculates the payload of the cylindrical shell to keep neutral buoyancy with optimized thickness in deep-sea applications.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.644-649
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• 1994

Recent studies reveal that grip forces due to repeated mechanical vasocompressions are most significant for the genesis of vibration-induced which finger syndrome (VWF). Therefore, exerted grip force was regarded as a dependent variable in 2 experiments and the effects of noise and vibrations of different weighted acceleration levels were studied. Neither grip forces nor peripheral blood flow as indicated by finger skin temperature were influenced by noise or vibrations. the cause of VWF is therefore presumed to be a concomitant variable which correlates with weighted accelerations and with grip forces as well. A possible factor is the weight of hand-held vibrating tools.

• Journal of Nutrition and Health
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• v.29 no.9
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• pp.991-1002
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• 1996

The objectives of this study were to obtain normative data for 45 mother-daughter pairs on spine, femur(neck, ward's triangle, trochanter) and total body BMD (bone mineral density) measured by dual energy X-ray absorptiometry, anthropometric measurement, body composition, biochemical markers, nutrient intakes and energy expenditure, to determin the interrelations of these factors within each group, to measure familial resemblance for each variable. We observed significantly positive correlations between height, weight, head, hip and calf circumferences, tricep, femur and calf skinfold thickness, total lean body mass(=weight-total fat body mass-bone mineral content), protein and fat intakes, Ca index, serum total protein and albumin of monter-daughter pairs(p<.05-p<.001). Among mothers, age, osteocalcin, higher, weight, Ca and energy intakes were predictors of BMDs. Among daughters, weight and energy intake were predictors of BMDs. The BMD in lumbar spine(r=.48, p<.01), femoral neck(r=.38, p<.05), ward's triangle(r=.36, p<.05) of the mothers were significantly correlated with those of the daughters, after adjustment for mother's age, hight, weight, osteocalcin, Ca and energy intakes and daughter's weight, energy intake. In regression analyses, mother's BMD also were positively associated with daughter's BMD in lumbar spine, femoral neck, ward's triangle. Our findings support that mothers with low BMD tended to have daughters with low BMD. In the age groups studied, as well genetic factors as environmental factors may have an important role in determining BMD. This study suggests that women may successfully enhance their genetically determined BMD through adequate nutrient intakes and weight bearing exercise.

• Journal of Families and Better Life
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• v.25 no.3 s.87
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• pp.77-87
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• 2007

This study purports to understand the direct and indirect effects between eating disorder behavior of female adolescents and their body-related variables(concerning the degree of diet regime, weight control, body satisfaction, and obesity), self-esteem and internal control, by checking three sub-categorized behavior of eating disorders of diet behavior, bulimia behavior, and eating control behavior. The sample group used for the study consisted of 190 female high school students and 292 female university students; measurement devices used for the study were those of body-related variables, self esteem and internal control, and eating disorder behavior; and data analysis was performed using ${\chi}2$, t-test, Pearson's correlation, regression analysis and path analysis. The results are as follows. First, there is a significant difference between university students and high school students regarding their body satisfaction, weight control experience, and self esteem. University students are more satisfied with their body, have higher self esteem, and control their weight better than high school students. Second, diet behavior shows a correlation with the degree of diet interest, weight control experience, and body satisfaction. Body satisfaction and internal control proved to be correlated with bulimia behavior, while weight control experience, obesity, and self esteem were correlated with eating control behavior. Third, the variables that showed a direct influence on diet behavior as an eating disorder are diet interest, weight control experience, body satisfaction and obesity, in that the explanatory power of the variables is 60.7% with the highest mark on obesity. The variables that showed effects on bulimia are body satisfaction and internal control with an explanatory power of 2.8%. Indirect variables effecting bulimia include objects, diet interest, body satisfaction, and self esteem. The variable with a direct influence on eating control behavior was self esteem with and explanatory power of 4%, whereas the variables of objects, diet interest, body satisfaction, weight control experience, and internal control were all indirectly correlated with eating control behavior.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.413-421
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• 2011

The present study was carried out to summarize the effect of garlic in the hyperlipidemia rats by meta-analysis related studies. The association measure to test effect of garlic was the mean difference (MD). In this particular fixed-effect model of mean difference, body weight, liver weight, kidney weight and heart weight were significantly decreased (p < 0.05). Also, blood glucose, plasma total cholesterol, plasma triglycerides, LDL-cholesterol, liver cholesterol, liver triglycerides were significantly decreased. HDL-cholesterol was significantly increased. In this case of heterogeneous variable, random effect model was applied. In this model, liver weight, blood glucose, plasma total cholesterol, plasma triglycerides, LDL-cholesterol, liver cholesterol, liver triglycerides were significantly decreased. HDL-cholesterol was significantly increased. According to the meta-regression analysis, duration of injection was significantly for kidney weight, testis weight, plasma total cholesterol, plasma triglycerides, HDL-cholesterol, LDLcholesterol, liver cholesterol, liver triglycerides.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.40-44
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• 2019

Purpose Glomerular filtration rate (GFR) is an important index for evaluation of renal function, renal disease diagnosis and progress monitoring. Therefore, accurate measurement of GFR is clinically important. Among the factors that affect the GFR result, there have been many discussions on the methods such as the correction of the kidney depth, net syringe count, and the method of setting the ROI. However there has been no consideration of counting in the most basic factors like height and weight measurement. In this study, we investigate how height and weight changes affects the result of GFR and review the importance of standardized body measurements. Materials and Methods Fifty patients who underwent GFR test were randomly sampled and examined for changes in height and body weight within one month. From the normal patients without renal disease to the patients with severely decreased GFR, we applied the GFR formula of Gate with varying height and weight. Results: The result showed variation of the height at maximum three centimeters and six kilograms of weight. The first calculation of GFR was done with fixed height value and control variable as weight. Weight was incremented by one kilogram each time up to six kilograms. The GFR showed increased result with increasing weight. The result of GFR showed ten percent increase with six kilograms of weight increase. On the other hand, when height value was incremented by one centimeter up to three centimeters showed decreased GFR result with fixed weight value. Up to three centimeters of height increase showed two percent of decreased GFR with fixed weight. Conclusion This study showed varying GFR result when height and weight changes. Therefore it is clinically crucial not only to maintain and manage body measuring instrument but also to have a standardized measurement methods to derive accurate measured values and to achieve reproducibility.

• Journal of Korean Public Health Nursing
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• v.19 no.1
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• pp.95-107
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• 2005

With the aim of diagnostic research on health education. the health promoting behaviors related to elementary school students' weight control. life satisfaction. health state. self-efficacy. parent's interest and knowledge about weight control and school health education of weight control were investigated on the basis of the PRECEDE model. The data for this study were collected from a sample at an elementary school in Chongju for 5 days in July. 2004. In analyzing the data. t-test. one-way ANOVA. chi-square test and multiple regression analysis were done by using SPSS 10.1 The results were as follows : 1. The elementary school students' level of life satisfaction was above half of the full point. The score difference of life satisfaction was statistically significant by grade and academic achievement(F=4.646. p=.010. F=16.042. p=.000). 2. The perceived level of health state was moderate for all students. Normal weight students' level was significantly higher than obese students' (t=3.667. p=.000). 3. The perceived level of health promoting behaviors related to weight control was above the moderate. The perceived level of health promoting behaviors related to weight control in the obese students was significantly higher than that in normal weight students(t=-2.225. p=.027). The students used computer for 1.48 hours and watched TV for 2.52 hours a day. 4. The score of health promoting behavior self-efficacy in this subject was 70.61. 5. The parents' level of interest in the obese students' weight control was significantly higher than that in the normal weight students(t=-4.86. p=.000). 6. Sixty-six percent of the students learned about weight control education in school. 7. The health promoting behavior self-efficacy among the educational diagnostic variables was the most influential variable in students' health promoting behaviors related to weight control. This research diagnosed the needs of weight control education in elementary school by assessing various factors related to weight control behaviors. The research findings suggest that we can enhance the prevention of childhood obesity by strengthening the related factors such as parents' knowledge and interest, health promoting behaviors and self-efficacy related to weight control in school health education.

• Journal of Preventive Medicine and Public Health
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• v.31 no.2 s.61
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• pp.199-214
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• 1998

This study was undertaken to explain weight control behavior and intention of obese children and adolescents as measured by the elements of the health belief model. A total of 732 obese students from 28 schools in Seoul metropolitan area and their mothers were assessed with a self-administered questionnaire. The analyzed results are as follows; 1. Among obese students, 45.3% of male students and 57.2% of female students, a significantly higher portion than male students, reported that they had tried to lose weight within the recent year. Exercise was the most frequently used method to lose weight followed by diet control, drug use, and specialized clinic visits, in descending order. 2. Male students were more likely to try to lose weight if they perceived a low threat level and their mother had a job, and female students were more likely to try to lose weight if they were younger in age, perceived a low threat level and had strong external motivating factors. 3. Female students showed a significantly higher level of intention to obesity control than male students, and the intention level of their mothers also showed the same trend. 4. In male students, the degree of weight dissatisfaction, weight control experience, the level of obesity related beliefs of students, the educational level of the mother and economic status of the family were significant predictors of intention to obesity control, and in females, age, the level of obesity related beliefs of students and intention of their mothers were significant. In the mothers of male students, obesity index of students, age of the mother and the level of obesity related beliefs of the mother were significant predictors of intention of the mother, and in the mothers of female students, obesity index of students, occupational status of the mother and obesity related beliefs of the mother were significant. 5. According to the path model of intention to obesity control, the degree of weight dissatisfaction had the most powerful effect in male students, and perceived net benefit level was the most important variable in female students. Since the weight control behavior and intention of obese students were more predictable by the degree of weight dissatisfaction than the obesity index, we can conclude that only the students dissatisfied with their weight are well motivated for obesity control. There can be a discrepancy between the mother and her child's beliefs and intention status(especially in male students), so the therapists should also assess the student's opinion as well as the mother's. In female students, the perceived net benefit level wag the most important predictor of intention to obesity control, therefore the intervention program should pay particular attention to the positive benefits of weight control rather than negative aspects(threats) of obesity.

• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.137-144
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• 2004

ECG signals are often contaminated with high-frequency noise such as muscle artifact, power line interference, and others. In the ECG signal processing, especially during a pre-processing stage, numerous noise removal techniques have been used to reduce these high-frequency noise without much distorting the original signal. This paper proposes a new type of digital filter with a continuously variable cutoff frequency to improve the signal quality This filter consists of a cutoff frequency controller (CFC) and variable cutoff frequency lowpass filter (VCF-LPF). From the noisy input ECG signal, CFC produces a cutoff frequency control signal using the signal slew rate. We implemented VCF-LPF based on two new filter design methods called convex combination filter (CCF) and weight interpolation fille. (WIF). These two methods allow us to change the cutoff frequency of a lowpass filter In an arbitrary fine step. VCF-LPF shows an excellent noise reduction capability for the entire time segment of ECG excluding the rising and falling edge of a very sharp QRS complex. We found VCF-LPF very useful and practical for better signal visualization and probably for better ECG interpretation. We expect this new digital filter will find its applications especially in a home health management system where the measured ECG signals are easily contaminated with high-frequency noises .