• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.793-796
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• 2008

Recently early strength concrete has been required for economical assurance and the prevention of frost damage in winter through air reduction in construction of concrete structures. This study presented the optimum condition revealing compressive strength 5MPa which has the possibility of removal of form in 24 hours, and researched the changes of unit weight of cement types of high early strength AE water reducing agents, characteristic of compressive strength expression as cure temperature conditions and slump or airspace. Test results showed at $15^{\circ}C$ with compressive strength of 5MPa that premature removal of form was possible in case of using highly early strength PC water reducing agent with unit weight of cement 360 ; 22hours faster than 10, unit weight 360 ; 20hours faster than 7, unit weight 390 ; 18 hours faster than 4 comparing with OP water reducing agent. And at $5^{\circ}C$ in case of using highly early strength PC water reducing agent with unit weight of cement 330 ; 32hours faster than 10, unit weight 360 ; 30hours faster than 7, unit weight390 ; 27hours faster than 4 comparing with OP water reducing agent. Therefore as the temperature rises $10^{\circ}C$, compressive strength of 5MPa reaching hour shortens 10 hours.

• Advances in concrete construction
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• v.5 no.5
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• pp.451-468
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• 2017

The problem of reducing the self-weight of reinforced concrete structures is very important issue. There are two approaches which may be used to reduced member weight. The first is tackled through reducing the cross sectional area by using voids and the second through using light weight materials. Reducing the weight of slabs is very important as it constitutes the effective portion of dead loads in the structural building. Eleven slab specimens was casted in this research. The slabs are made one way though using two simple supports. The tested specimens comprised three reference solid slabs and eight styropor block slabs having (23% and 29%) reduction in weight. The voids in slabs were made using styropor at the ineffective concrete zones in resisting the tensile stresses. All slab specimens have the dimensions ($1100{\times}600{\times}120mm$) except one solid specimens has depth 85 mm (to give reduction in weight of 29% which is equal to the styropor block slab reduction). Two loading positions or cases (A and B) (as two-line monotonic loads) with shear span to effective depth ratio of (a/d=3, 2) respectively, were used to trace the structural behavior of styropor block slab. The best results are obtained for styropor block slab strengthened by minimum shear reinforcement with weight reduction of (29%). The increase in the strength capacity was (8.6% and 5.7%) compared to the solid slabs under loading cases A and B respectively. Despite the appearance of cracks in styropor block slab with loads lesser than those in the solid slab, the development and width of cracks in styropor block slab is significantly restricted as a result of presence a mesh of reinforcement in upper concrete portion.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.3
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• pp.15-23
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• 2013

Weight reduction of a automobile has been steadily tried in automotive industry to improve fuel efficiency, driving performance and the production profits. Since the weight of BIW takes up a large portion of the total weight of the automobile, reducing the weight of BIW greatly contributes to reducing the total weight of the vehicle. To reduce weight, vehicle manufacturers have tried to apply lightweight materials, such as aluminum and high-strength steel, to the components of BIW instead of conventional steel. In this research, material arrangement of an automotive BIW was optimized by formulating a design problem to minimize weight of the BIW while satisfying design requirements about bending and torsional stiffness and perform a metamodel-based design optimization strategy. As a result of the design optimization, weight of the BIW is reduced by 45.7% while satisfying all design requirements.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.610-615
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• 2001

In the interest of improved automotive fuel economy, one solution is reducing vehicle weight. Achieving significant weight reductions will normally require reducing the panel thickness or using alternative materials such as aluminum alloy sheet. These changes will affect the dent resistance of the panel. In this study, the correlation between panel size, curvature, thickness, material properties and dent resistance is investigated. A parametric approach is adopted, utilizing a "design software" tool incorporating empirical equations to predict denting and panel stiffness for simplified panels. The developed design program can be used to minimize panel thickness or compare different materials, while maintaining adequate panel performance.

• Nutrition Research and Practice
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• v.4 no.6
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• pp.499-506
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• 2010

The study aimed to analyze the lifestyles, weight control behavior, dietary habits, and depression of female university students. The subjects were 532 students from 8 universities located in 4 provinces in Korea. According to percent ideal body weight, 33 (6.4%), 181 (34.0%), 283 (53.2%), 22 (4.1%) and 13 (2.5%) were severely underweight, underweight, normal, overweight and obese, respectively, based on self-reported height and weight. As much as 64.1 % and only 2.4%, respectively, overestimated and underestimated their body weight status. Six overweight subjects were excluded from overestimation group for the purpose of this study, resulting in overestimation group consisting of only underweight and normal weight subjects. Compared to those from the normal perception group, significantly more subjects from the overestimation group were currently smoking (P=0.017) and drank more often than once a week (P=0.015), without any significant differences in dietary habits. Despite similar BMIs, subjects who overestimated their own weight statuses had significantly higher weight dissatisfaction (P= 0.000), obesity stress (P= 0.000), obsession to lose weight (P = 0.007) and depression (P = 0.018). Also, more of them wanted to lose weight (P = 0.000), checked their body weights more often than once a week (P=0.025) and had dieting experiences using 'reducing meal size' (P=0.012), 'reducing snacks' (P=0.042) and 'taking prescribed pills' (P = 0.032), and presented 'for a wider range of clothes selection' as the reason for weight loss (P = 0.039), although none was actually overweight or obese. Unlike the case with overestimating one's own weight, being overweight was associated with less drinking 0.035) and exercising more often (P=0.001) and for longer (P=0.001) and healthier reasons for weight control (P=0.002), despite no differences in frequency of weighing and depression. The results showed that weight overestimation, independent of weight status, is associated with risky lifestyles, weight control behaviors, and mental conditions. Preventive interventions should focus not only on obesity, but also on body weight overestimation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1018-1025
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• 2002

This study aimed to assess the prevalence of weight control behaviors and their association with food and nutrient intake among Korean adults. Study subjects were 7,340 Koreans aged 20 years and older in the 1998 Korean Health and Nutrient Survey. Cross-sectional data were collected on weight control behavior and diet using structured questionnaire by interview. Analysis of variance following after Duncan's multiple range test was used to test the differences in food and nutrient intake among three different weight control behavior groups(weight reducing attempt, weight gaining attempt, none). Current weight control behaviors were reported by 32% of the study subjects. There were significant differences in weight control behaviors between male and female subjects; weight reducing practices were 7 times greater than weight gaining practices among female subjects while it was only 1.5 times among male subjects. Weight control behaviors were not consistently associated with food and nutrient intake among male and female subjects. Moreover, greater food and nutrient intake were observed among those who trying to reducing weight than those who did not try. Therefore, it Is necessary to educate the Korean adults that balanced food and nutrient intake with sustaind weight control effort is the ideal way to achieve healthy weight.

• Journal of Korean Medicine for Obesity Research
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• v.16 no.2
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• pp.116-123
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• 2016

Objectives: The purpose of this study was to investigate the effects of modified fasting therapy on the changes of body compositions. Methods: We analyzed the medical records of 33 patients, who carried out modified fasting therapy at Dunsan Korean Medicine Hospital of Daejeon University from January 1st, 2011 to December 30th, 2015. They went through reducing food intakes period (7 days), fasting period (14 days) and refeeding period (14 days). Body compositions (weight, body mass index, skeletal muscle mass, percent body fat, basal metabolic rate, waist-hip ratio, visceral fat area) were reviewed at each state. And then the data was analyzed. Results: The body composition values (weight, body mass index [BMI], skeletal muscle mass, percent body fat, basal metabolic rate, waist-hip ratio, visceral fat area) decreased during the fasting therapy period, as a whole. The weight, BMI, percent body fat and visceral fat area decreased during the reducing food intakes period, the fasting period and the refeeding period. The skeletal muscle mass and basal metabolic rate significantly decreased during the reducing food intakes period and the fasting period, and insignificantly increased during the refeeding period. Conclusions: Results from this investigation showed that modified fasting therapy using fermented herbal medicine have positive effects on changes of body compositions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.2
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• pp.213-221
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• 2011

In this study, we discussed the weight reducing of a urban railway-car body, in particular, of the Korean EMU, by optimizing topology and size of aluminum extrusion profiles. The heaviest parts of aluminum railway-car bodies, i.e., the base plate of underframe and side panels of side frame composed of double skin structures are considered for optimization. Topology optimization process is applied to obtain get an optimized rib structure for the base plate. The thickness of ribs and plates of the topologically optimized base plate and the existing side panel are also optimized by employing the size optimization process. The results are verified by comparing the maximum von Mises stresses and maximum deformation in the case of the existing design with those in the case of the optimized design. It is shown that the weight of a base plate and side panel can be reduced by 12% and that the weight of the whole car body can be reduced by 8.5%.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.169-173
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• 2008

This study is concerned with adopting the hydroforming method in the front axle of the commercial vehicle. Generally the front axle of the commercial vehicle is made bγ the several operations of press forging. This product supports the big weight of the vehicle and load. The weight of the press forging parts is also so more than it of the press parts of the passenger car. So, we have studied the hydroforming method to lessen the weight of the front axle of the commercial vehicle. To apply the hydroforming method in the commercial vehicle, we had to use the operation of reducing the diameter of the used tube prior to the hydorforming operation.

• Korean Journal of Pharmacognosy
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• v.38 no.2 s.149
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• pp.152-156
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• 2007

Protein-bound polysaccharide is derived from Acanthopananx senticosus by the cold water extraction. The aim of the study was to evaluate the effects of PS against weight loss and hematological change as a indication of toxicity produced by the treatment of cisplatin. PS protected the weight loss caused by cisplatin (6 mg/kg) and significantly recovered hematological change. Treatment of PS showed the recovery on the weight loss and hematological change as indicators of toxicity of cisplatin treatment. By increasing lymphocyte proliferation and cytokine production, PS may be highly effective in protecting against cisplatin-induced toxicity. The results suggest PS might have a role in reducing toxicity or permitting larger dose of cisplatin to be given.