• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.656-660
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• 2002

The fiber reinforced composite material is widely used in the multi-industrial field where the weight reduction of the infrastructure is demanded because of their high specific modulus and specific strength. Pressure vessels using this composite material in comparison with conventional metal vessels can be applied in the field where lightweight and the high pressure is demanded from the defense and aerospace industry to rocket motor case due to the merits which are energy curtailment by the weight reduction and decrease of explosive damage precede to the sudden explosion which is generated by the pressure leakage condition. In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding composite pressure vessel receiving an internal pressure, the standard interpretation model is developed by using the ANSYS 5.7.1, the general commercial program, which is verified as the accuracy and useful characteristic of the solution based on Auto LISP and ANSYS APDL. Both the preprocessor for doing exclusive analysis of filament winding composite pressure vessel and postprocessor that simplifies result of analysis have been developed to help the design engineers.

• Journal of the Korean Institute of Gas
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• v.10 no.4 s.33
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• pp.23-28
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• 2006

This paper presents the strength safety and the weight reduction analysis of nine gas valve models for a LPG cylinder using a finite element analysis program, MARC and Taguchi's experimental method. The maximum Von Mises stress of a gas valve body represents a safety of a brass valve structure for the given gas pressure of $91kg/cm^2$, which considered a safety factor of a LPG gas cylinder. The weight reduction analysis is very important for reducing a gas flow friction loss and a manufacturing cost as a design parameter. The calculated results present an design model 9 as an optimized design data with 10mm radius of a lower part gas flow pipe A, 6mm radius of an upper part gas flow pipe B and a connecting length 2 mm of tapered pipe D between lower and upper pipes.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.12
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• pp.953-960
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• 2020

This paper presents an optimization of gear web design used in a main gear train of an engine reduction gearbox for a rotorcraft. The optimization involves the minimization of a total weight, transmission error, misalignment, and face load distribution factor. In particular, three design variables such as a gear web thickness, location of rim-web connection, and location of shaft-web connection were set as design parameters. In the optimization process, web, rim and shaft of gears were converted from the 3D CAD geometry model to the finite element model, and then provided as input to the gear simulation program, MASTA. Lastly, NSGA-II optimization method was used to find the best combination of design parameters. As a result of the optimization, the total weight, transmission error, misalignment, face load distribution factor were all reduced, and the maximum stress was also shown to be a safe level, confirming that the overall gear performance was improved.

• Journal of Nutrition and Health
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• v.41 no.7
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• pp.634-664
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• 2008

This study investigated the effects of the nutrition education on body weight, visceral fat and diet quality in the postmenopausal women. The subjects (n = 101) were randomly divided into two groups: Nutrition education + Exercise (NEE) group (n = 51) and Exercise only (EO) group (n = 50). Nutrition education was consisted of counseling in portion control, food selection for low carbohydrate, high fiber food items and for the improvement in micronutrient intakes and diet quality. After 6 months, the reduction in the body weight and visceral fat area was significantly greater in the NEE than in the EO group. The NEE subjects were further divided into two groups according to the amount of visceral fat area reduction; high visceral fat area loss (HVL) group with a visceral fat area reduction 2.35% or greater and low visceral fat area loss (LVL) group with a reduction less than 2.35%. In the HVL group, the reduction in body weight, BMI, percent body fat, waist to hip ratio and visceral fat area was significantly greater than that in the LVL group. We observed a significant increase in the serum HDL-cholesterol level and a decrease in systolic blood pressure, fasting blood sucrose, total and LDL-cholesterol levels in the HVL group compared to the LVL group. The energyadjusted protein, fiber, calcium, vitamin $B_6$, vitamin C, vitamin E intakes were significantly increased in the HVL compared to LVL group. The index of nutritional quality (INQ) and mean adequacy ratio (MAR) were also increased in the HVL group compared to the LVL group. These results show that our nutrition education program was an effective intervention measure for the reduction of body weight and visceral fat, blood pressure, glucose and lipid levels in the blood and also for the improvement of nutrient intake and diet quality in postmenopausal women who are overweight.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.148-159
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• 1998

Spot welding palys a key role in increasing productivity and weight reduction of the final products. This paper proposes a systematic approach on the design of spot weld configuration, dealing with the requried number and location of spot weld joints under the given design parameters, such as the applied loads, lap area, and individual spot weld strength. The optimal design of a spot-welded joint is postulated as a state when the safety factors of all spot weld points (i) are evenly distributed and (ii) reach maximum value. A CAD program is developed to arrange the optimal location of each spot weld based on the derived objective function and constraints. The CAD tool integrates the optimization procedure with Finite Element Analysis (FEA) code through an interface. The interface automatically provides geometrical data and mesh configuration for different spot weld locations to FEA model. It also extracts the transmitted load of each spot weld from the FEA code, and allows the optimization code predict an improved arrangement of spot weld locations. The feasibility of the developed approach is demonstrated by the selected examples.

• Journal of the Korean Dietetic Association
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• v.11 no.1
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• pp.125-132
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• 2005

Hypercholesterolemia has been regarded as a major risk factor of coronary heart disease(CHD). CHD is increasing in recent years among Koreans due to westernization of lifestyle and dietary behaviors. In the United States, implementation of the National Cholesterol Education Program(NCEP) had resulted 40% decline in mortality from CHD. This study was designed to evaluate the effect of medical nutrition therapy on serum lipid levels and discuss the effective nutrition education contents. Thirty outpatients(Male 40%, female 60%) with hypercholesterolemia were educated by medical nutrition therapy(MNT) protocol. At first visit and after three months of MNT, we assessed serum lipid profile, body weight and surveyed general characteristics, lifestyle and food habits through questionnaire. After 12 weeks of MNT, there were significant reductions in serum cholesterol and low-density lipoprotein cholesterol(LDL-C). Foods habits and lifestyle were changed to the desirable patterns. These results indicate that lipid profile is improved by changes of dietary behaviors and lifestyle. Especially in case of obesity, cholesterol lowering effect of MNT was more powerful. Consequently, MNT is effective on reduction of serum lipids by behavior change in hypercholesterolemic patients.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.217-220
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• 2003

Due to the lighter weight and the higher freedom of design than metals plastics have been spot lighted in a wide number of applications. In the making plastic parts injection-molding process is one of the most general methods. During the injection molding process, filling-packing-cooling process, plastics have exposed to several external stresses and then plastic parts injected have molding effects which are known as anisotropic properties, orientation, and residual stress. Those molding effects are often shown as unexpected phenomena which are warpage, strength decrease, stiffness reduction, etc. In case of glass fiber filed plastics these effects are more significant than the ufilled ones. Therefore the molding effects have to be considered in the parts design using glass fiber reinforced plastics. We have developed the interface program in order to consider the molding effects in structural analyses of plastic parts using Heirarchical structural searching and layer handling in direction of thickness algorithm. The advantages of this program are the freedom of FE mesh between molding and structural analysis, the variable layer to the thickness direction of parts and the conveniences of data transferring and checking

• Journal of Preventive Medicine and Public Health
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• v.42 no.1
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• pp.42-48
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• 2009

Objectives : This study was conducted to examine the factors implicated when people start smoking again after a 6 month cessation, and was carried out at the smoking cessation clinic of a public health center. Methods : The study subjects were 191 males who had attended the smoking cessation clinic of a public health center for 6 months in an attempt to quit smoking. Data was collected, by phone interview, regarding individual smoking habits, if any, over the 6 month study period. The factors which may have caused an individual to smoke again were examined. This study employed a health belief model as it theoretical basis. Results : Following a 6 month cessation, 24.1% of the study group began to smoke again during the 6 month test period. In a simple analysis, the factors related to individuals relapsing and smoking again included barriers of stress reduction, body weight gain and induction of smoking by surroundings among perceived barriers factor of our health belief model(p<0.05). In multiple logistic regression analysis for relapsed smoking, significant factors included barriers of stress reduction and induction of smoking by surroundings(p<0.05). The most important reason of for an individual to relapse into smoking was stress(60.9%) and the most likely place for a relapse to occur was a drinking establishment(39.1%). Conclusions : Our results indicate that both regular consultations and a follow-up management program are important considerations in a public health center program geared towards maintaining smoking cessation.

• The Korea Journal of Herbology
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• v.31 no.1
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• pp.17-23
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• 2016

Objectives : This study was designed to protect effect on atherosclerosis through regulation of low density lipoprotein(LDL) by 70 % ethanol extract Ganoderma lucidum (GL) in LDL receptor knockout mouse (LDLr ko mice) fed Western diet.Methods : The LDLr ko mice were divided into 3 groups ; Control, GL100, and GL300. After grouping, LDLr ko mice were fed Western diet. The GL (100 or 300 mg/kg body weight/day, p.o.) was administered every day for 8 weeks. The body weight and food intake were measured every day. The changes in the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, triglyceride (TG), total cholesterol (TC), and high-density lipoprotein (HDL) in serum were analyzed after experiment.Results : The LDLr ko mice fed Western diet were increased body weight gain and blood biochemistry parameters such as ALT, AST, TG, TC, and LDL. However GL300 group significantly reduced the body weight. Also TG, TC, and LDL level did not increase. The levels of ALT, AST, HDL were not changed. Also, LDLr ko mice model liver were observed lipid drop, but GL groups did not appear. Futhermore, histological analysis of GL groups aorta tissue were similar to NOR groups.Conclusions : We confirmed that whether GL administration is protect atherosclerosis or not. As the results, blood biochemistry and histological analysis did not changed much in GL administration groups. This study provides scientific evidence that GL protect the atherosclerosis through the reduction of LDL cholesterol. Therefore GL has potential medicine inhibition of atherosclerosis.

• Nutrition Research and Practice
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• v.8 no.4
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• pp.469-475
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• 2014

BACKGROUND/OBJECTIVE: The goal of the present study was to investigate the effects of moderate caloric restriction on ${\beta}$-cell function and insulin sensitivity in middle-aged obese Korean women. SUBJECTS/METHODS: Fifty-seven obese pre-menopausal Korean women participated in a 12-week calorie restriction program. Data on total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), and fasting serum levels of glucose, insulin, C-peptide, blood pressure, leptin and anthropometrics were collected. A dietary intake assessment was based on three days of food recording. Additionally, ${\beta}$-cell function [homeostasis model assessment of ${\beta}$-cell (HOMA-${\beta}$), insulinogenic index (ISI), C-peptide:glucose ratio, and area under curve insulin/glucose ($AUC_{ins/glu}$)] and insulin sensitivity [homeostasis model assessment for insulin resistance (HOMA-IR), Quantitative insulin-sensitivity check index (QUICKI) and Matsuda index (MI)] were recorded. RESULTS: When calories were reduced by an average of 422 kcal/day for 12 weeks, BMI (-2.7%), body fat mass (-10.2%), and waist circumference (-5%) all decreased significantly (P < 0.05). After calorie restriction, weight, body fat percentage, hip circumference, BP, TC, HDL-C, LDL-C, plasma glucose at fasting, insulin at fasting and 120 min, $AUC_{glu}$ and the insulin area under the curve all decreased significantly (all P < 0.05), while insulin sensitivity (HOMA-IR, QUICKI and Matsuda index) measured by OGTT improved significantly (P < 0.01). CONCLUSIONS: Moderate weight loss due to caloric restriction with reduction in insulin resistance improves glucose tolerance and insulin sensitivity in middle-aged obese women and thereby may help prevent the development of type 2 diabetes mellitus.