• The Korean Journal of Applied Statistics
• /
• v.26 no.4
• /
• pp.635-647
• /
• 2013

Imputation is a commonly used method to handle missing survey data. The performance of the imputation method is influenced by various factors, especially an outlier. The removal of the outlier in a data set is a simple and effective approach to reduce the effect of an outlier. In this paper in order to improve the precision of multiple imputation, we study a imputation method which reduces the effect of outlier using various weight adjustment methods that include the removal of an outlier method. The regression method in PROC/MI in SAS is used for multiple imputation and the obtained final adjusted weight is used as a weight variable to obtain the imputed values. Simulation studies compared the performance of various weight adjustment methods and Monthly Labor Statistic data is used for real data analysis.

• Applied Microscopy
• /
• v.48 no.3
• /
• pp.62-72
• /
• 2018

This study investigated the anti-obesity effect of a pear (Fructus Pyri Pyrifoliae) extract fermented by lactic-acid bacteria on obesity induced by a high-fat diet in rats. Body-weight measurement, blood analysis, and light microscope observation of adipose tissue in liver and epididymis were conducted after 8 weeks. Gene expression of leptin, adiponectin, and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) in liver cells were also investigated. Compared to CON, PFA and PFB showed 8% weight reduction along with weight reduction of adipose tissue in liver and epididymis. Observing the microstructure of liver cells showed that lipid droplets were smaller in PFA and PFB than in CON. We confirmed that Fructus Pyri Pyrifoliae extract fermented by lactic-acid bacteria can affect gene expression of leptin, adiponectin, and $TNF-{\alpha}$ in liver cells, showing an obesity treatment effect. From the results above, it was observed that weight gain from increased gene expression in adipose cells as well as from the increased proportion of adipose cells caused by a high-fat diet can be statistically significantly reduced by taking Fructus Pyri Pyrifoliae extract fermented by lactic-acid bacteria. Therefore, Fructus Pyri Pyrifoliae extract fermented by lactic-acid bacteria can be effective for preventing and treating obesity by reducing weight and adipose cells.

• Food Science and Biotechnology
• /
• v.18 no.1
• /
• pp.197-201
• /
• 2009

This study evaluated the effect of biocellulose and the diet formulation on reducing body weight gain of obese rats induced by high-fat diet for 10 weeks. Thirty male Sprague-Dawley rats were randomly assigned to high-fat diet group (OB-CON), high-fat diet group containing 5% biocellulose (OB-BIO), and high-fat diet group containing 5% dietary formulation (OB-DF). After feeding each diet for additional 10 weeks, body weight gains of OB-BIO and OB-DF groups were lower by 3.3 and 4.8%, respectively as compared with that of OB-CON group. Although not significant, measured values of the perirenal and visceral fat pads of OB-BIO and OB-DF groups were lower than those of the OB-CON group. The weight of interscapular brown adipose tissue did not show significant difference in all groups. The size of adipocyte in rats was lower in both OB-BIO and OB-DF groups. Thus, biocelluose and the diet formulation showed the anti-obesity effect.

• Korean Journal of Health Education and Promotion
• /
• v.21 no.2
• /
• pp.133-146
• /
• 2004

Purpose： The purpose of this study was to investigate the actual conditions of obesity, and the factors related to children's obesity. Method： The subjects were 568 students (5th, 6th grades) of ten elementary schools in a small city of about 350,000. Subjects self-reported after being instructed by researchers to identify health habits and attitudes toward obesity. The Rohrer index was calculated by using annual physical examinations preformed by the schools. Result： 17.5％ of the subjects were under weight, 22.2％ were overweight, and 60.3％ were normal. In girls, the under weight group was much larger, in boys the overweight group was larger. 46.2％ of overweight children had a familial tendency to obesity. 60.6％ of boys and 60％ of girls were on a diet in order to improve their looks or to prevent ridicule from mends. On average, one-third of the subjects misunderstood their own weight level. Subjects spent 3-4hours on weekdays, and over 6hours on the weekend watching TV or using personal computers. The overweight group enjoyed eating meat, fish, beans and vegetables, while the normal group tended to prefer fruit. Conclusion： Health education programs which guide elementary school students to form better health habits, more accurate perceptions of their own body weight, and better attitudes toward obesity and which make students aware of the importance of exercise, a healthy diet, and reducing time spent in front of TVs and computers may help them to keep at their appropriate weight.

• Tribology and Lubricants
• /
• v.39 no.3
• /
• pp.94-101
• /
• 2023

Automotive wheel bearings are a critical component of vehicles that support their weight and facilitate rotation. Life and stiffness are significant performance characteristics of wheel bearings. Designing wheel bearings involves finding optimal design variables that satisfy both performances. CO₂ emission reduction and fuel efficiency regulations attribute to the recent increase in design requirements for lightweight and compact automotive parts while maintaining performance. However, achieving a design that maintains performance while reducing weight poses challenges, as performance and weight are generally inversely proportional. In this study, we perform design optimization of automotive wheel bearings considering life and stiffness. We develop a program that calculates the basic rated life and modified rated life based on international standards for evaluating the life of wheel bearings. We develop a regression equation using regression analysis to address the time-consuming stiffness analysis during repetitive analysis. We perform ANOVA and main effect analyses to understand the statistical characteristics of the developed regression equation. Furthermore, we verify its reliability by comparing the predicted and test results. We perform design optimization using the developed life prediction program, stiffness regression equation and weight regression equation. We select bearing specifications and geometry as design variables, weight as the cost function, and life and stiffness as constraints. Through design optimization, we investigate the influence of design variables on the cost function and constraints by comparing the initial and optimal design values.

• Journal of Preventive Medicine and Public Health
• /
• v.37 no.4
• /
• pp.306-311
• /
• 2004

Background : The roles of antioxidants in the placenta and genetic susceptibility to oxidant chemicals in relation to neonatal birth weight have not been elucidated. We determined whether the level of placental manganese superoxide dismutase (MnSOD) and its genetic polymorphism plays any role in oxidative stress and neonatal birth weight. Methods : We measured placental MnSOD and determined MnSOD genetic polymorphism among 108 pregnant women who were hospitalized for delivery and their singleton live births in Korea. Main outcome measurements are maternal urinary malondialdehyde (MDA) and birth weight. Results : Maternal urinary concentrations of MDA were significantly associated with neonatal birth weight (P=0.04). The enzyme level of placental MnSOD was also significantly associated with MDA concentration (P=0.04) and neonatal birth weight (p<0.01). We observed dose-response relationships between placental MnSOD and maternal urinary MDA, and neonatal birth weight after adjusting for maternal weight, height, age, and neonatal sex. After controlling for covariates, MnSOD variant genotype increased maternal urinary MDA concentrations (p<0.01) and reduced birth weight by 149 gm (P=0.08). Conclusions : This study demonstrates that the placental level of MnSOD during pregnancy significantly affects fetal growth by reducing oxidative stress, and that genetic polymorphism of MnSOD probably modulate the effects of oxidants on fetal growth.

• Journal of Dairy Science and Biotechnology
• /
• v.28 no.1
• /
• pp.53-59
• /
• 2010

The milk product is one of the major foods which provide calcium for nutritional requirement. In addition to calcium, it supplies diverse nutrients including protein, potassium, vitamin A, vitamin $B_1$, and vitamin $B_2$. Adequate calcium intake throughout lifetime ensures optimum bone density and prevents osteoporosis in old age by reducing loss of bone mineral during growth and aging. The nutritional deficiency of calcium intake and spreading of osteoporosis in Korean population accentuated necessity of adequate calcium intake through milk consumption. Obstruction of milk consumption due to lactose intolerance should be overcome by educational programs for adequate milk consumption and low-lactose milk product developments. Consumption of milk products was reported to prevent high blood pressure in clinical studies and epidemiological investigations. As the feeding of milk increased, the body weight and fat of animal decreased in animal studies. The epidemiological investigations revealed that there was a negative correlation between the amount of milk consumption and the body fat. When calcium was provided as dietary supplement in the clinical trials, the body weight and body fat of subjects decreased. When calcium was particularly supplied as a part of milk, the body weight reduction rate was augmented. Calcium, vitamin D, and conjugated linoleic acid have been reported to exert a role in reducing cancer. The paramount importance of milk in nutrition as a source of calcium and other invaluable nutrients emphasizes consistent supply of milk products to adults as well as adolescents by dairy industry.

• Journal of Nutrition and Health
• /
• v.34 no.4
• /
• pp.417-425
• /
• 2001

The purpose of this study was to confirm that regular physical exercise habit and calcium intake play a role in reducing the risk of cardiovascular disease, particularly to confirm that regular exercise is important in reducing serum lipid levels in postmenopausal women. Subjects were classified into regular exercise group(more than 3 times/wk, more than 30 min per exercise) and non-regular exercise group. A convenient frequency method was used to assess the nutritional intake of subjects. Anthropometric measurement such as body weight and height, and blood pressure were measured. There was no significant difference between non-regular exercise group and regular exercise group in energy intake and calcium intake. The total cholesterol and LDL-cholesterol concentrations in non-regular exercise group were significantly higher than those in regular exercise group. There were no significant correlations between age or weight with blood lipids and blood pressure in regular exercise group, while there were significant positive correlations between age or weight with blood lipids and blood pressure in non-regular exercise group. The levels of serum cholesterol, triglyceride, blood pressure and atherogenic index increased with age in non-regular exercise women. The blood pressure in low total Ca intake/plant Ca intake ratio group was significantly higher than that in high total Ca intake/plant Ca intake ratio group. There was a highly significant positive correlation between Ca intake and HDL-cholesterol in non-regular exercise women. And, there was a highly significant negative correlation between Ca intake and blood pressure in regular exercise women. The results suggest that increased habitual physical activity and calcium intake should be recommended by way of decreasing blood lipids and blood pressure in postmenopausal women. (Korean J Nutrition 34(4) : 417∼425, 2001)

• Journal of Adhesion and Interface
• /
• v.14 no.1
• /
• pp.21-27
• /
• 2013

Cellulose-based rayon fibers or fabrics can be thermally decomposed very fast within a narrow temperature window during stabilization process. Therefore the stabilization stage is critically important for producing rayon-based carbon fibers. Consequently, in the present study the effects of isothermal stabilization and ultrasonic cleaning on the weight loss, chemical composition, microstructure, and fabric texture of cellulose-based rayon fabrics were explored. The temperature of the isothermal stabilization process performed in the range of $200{\sim}240^{\circ}C$ influenced the processing time, carbon and oxygen contents, cellulose structural change, and fabric texture. The ultrasonic cleaning, which was conducted prior to the stabilization process, played a role in shortening the stabilization time, increasing the carbon contents, decreasing the oxygen contents, and changing the XRD pattern. Also, it was considered that the ultrasonic cleaning contributed to retarding the weight loss, to reducing the thermal shrinkage, and further to reducing the fast physical change of rayon fabrics.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.27 no.5
• /
• pp.107-113
• /
• 2000

The purpose of this study is to investigate the effects of soil amendments for reducing soil compaction at heavy traffic area in golf course. Major results of this research are summarized at follows: 1. In the Lab. experiment, the porosity was improved significantly when the materials, such as peatmoss, charcoal, and tire chip mixtures were used respectively. Especially mixture of sand and 20% peatmoss showed higher effectiveness (10%) in porosity, comparing with ordinary sand. This soil mixture(sand 80%+peatmoss 20%) was observed the best in water retention, soil hardness and hydrauric conductivity. 2. In the greenhouse experiment, traffic pressure was given 7 times a day on several combination of mixture treatments to see the top dry weight. The soil mixture of 20% peatmoss showed the highest in the top dry weight. When the more traffic pressure(15 time/day) were given on the different treatment, the top dry weight was significantly reduced. However, the mixture of 20% peatmoss also had the least influence on this type of heavy traffic. 3. In the field experiment, the soil amendments were treated in traffic area f golf course, and observed at 30days, 60days, 90days, 120days after treatment. Visual turf quality(color), root length and soil compaction were compared to those of control. As a result, overall treatments with soil amendments were effective, which showed better turf quality and less soil compaction. 4. In the field test, physical characters of soil (such as soil hardness and hydrauric conductivity) in sand+tire chip+peatmoss(60:20:20, %, v/v) treatment was significantly improved. Also in the slow increasing of traffic, the soil compaction was the most effective in reducing soil hardness.