• Health Policy and Management
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• v.30 no.4
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• pp.493-504
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• 2020

Background: There have been many studies on the associations between body mass index (BMI) and cognitive function. However, no study has ever compared the associations across the methods of categorizing BMI. In this study, we aimed to fill the gap in the previous studies and examine whether the obesity paradox is valid in the risk of cognitive function. Methods: Of the 10,254 people aged 45 and older from the Korean Longitudinal Study of Ageing from 2006 to 2016, 8,970 people were finalized as the study population. The dependent variable was whether a person has a normal cognitive function or not, and the independent variables of interest were BMI categorized by the World Health Organization Western Pacific Regional Office (WHO-WPRO) method, the WHO method, and a 10-group method. Covariates included sociodemographic factors, health behavior factors, and health status factors. A generalized linear mixed model analysis with a logit link was used. Results: In the adjusted model with all covariates, first, in the case of BMI categories of the WHO-WPRO method, underweight (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.15-1.17), overweight (OR, 1.36; 95% CI, 1.35-1.36), and obese (OR, 1.34; 95% CI, 1.33-1.34) groups were more likely to have a normal cognitive function than a normal-weight group. Next, in the case of BMI categories of the WHO method, compared to a normal-weight group, underweight (OR, 1.15; 95% CI, 1.14-1.16) and overweight (OR, 1.06; 95% CI, 1.06-1.07) groups were more likely to have a normal cognitive function; however, obese (OR, 0.62; 95% CI, 0.61-0.63) group was less likely to have it. Lastly, in the case of the 10-group method, as BMI increased, the likelihood to have a normal cognitive function changed like a wave, reaching a global top at group-7 (26.5 kg/㎡ ≤ BMI <28.0 kg/㎡). Conclusion: The associations between BMI and cognitive function differed according to how BMI was categorized among people aged 45 and older in Korea, which suggests that cognitive function may be positively associated with BMI in some categories of BMI but negatively in its other categories. Health policies to reduce cognitive impairment need to consider this association between BMI and cognitive function.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.831-838
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• 2006

An experimental/analytic study has been conducted to understand the adverse effects of low vehicle speed, high axle load and high tire pressure on the performance of asphalt pavements. Of 33 asphalt sections at KHC test road, two sections having different base layer thickness (180 mm versus 280 mm) are adopted for rollover tests. During the test, a standard three-axle dump truck maintains a steady state condition as moving along the wheel path of a passing lane, and lateral offsets and real travel speed are measured with a laser-based wandering system. Test results suggest that vehicle speed affects both longitudinal and transverse strains at the bottom of asphalt layer (290 mm and 390 mm below the surface), and even slightly influences the measured vertical stresses at the top of subbase and subgrade due to the dynamic effect of rolling vehicle. Since the anisotropic nature of asphalt-aggregate mixtures, the difference between longitudinal and transverse strains appears prominent throughout the measurements. As the thickness of asphalt pavement increases, the measured lateral strains become larger than its corresponding longitudinal strains. Over the limited testing conditions, it is concluded that higher axle weight and higher tire pressures induce more strains and vertical stresses, leading to a premature deterioration of pavements. Finally, a layered elastic analysis overestimates the maximum strains measured under the 1st axle load, while underestimating the maximum vertical stress in both pavement sections.

• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.16-22
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• 2019

This study proposed estimation methods for weight and center of gravity of small fishing vessels. Weights loaded on small fishing vessels were divided into fixed weights such as crew, fishing gear, and variable weights such as fuel, fresh water, provision, bait, and fish. Based on statistical analyses with weight data of several small fishing vessels, weight, longitudinal center of gravity (LCG), vertical center of gravity (KG) of each item were represented as linear functions of vessel gross tonnage. In addition, weighting factors of variable weights were added on estimation formulas in accordance with vessel loading conditions, e.g. full load departure condition. Estimation methods were verified using actual small fishing vessel data.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.617-626
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• 2011

Seven post-tensioned lightweight concrete (LWC) beam specimens were tested under a symmetrical two-point top loading system. The parameters investigated were the amounts of mild longitudinal reinforcement and effective prestressing. The design compressive strength and dry density of the LWC tested were 30 MPa and 1,770 $kg/m^3$, respectively. Similar to post-tensioned normal weight concrete (NWC) beams, the crack propagation and stress increase of the unbonded tendons were significantly affected by the amounts of mild longitudinal reinforcement and effective prestressing. With the increase in the amounts of mild longitudinal reinforcement and effective prestressing, the serviceability and flexural capacity of the beams were enhanced whereas the stress increase in the unbonded tendons decreased. To control the crack width in post-tensioned LWC beams, a minimum amount of mild longitudinal reinforcement specified in ACI 318-08 provision is required. The flexural behavior of post-tensioned LWC beams and stress increase of the unbonded tendons could be rationally predicted by the proposed non-linear two-dimensional analysis. On the other hand, ACI 318-08 flexure provision was too conservative about the post-tensioned LWC beams.

• Korean Journal of Health Education and Promotion
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• v.9 no.1
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• pp.88-102
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• 1992

The exact estimation of physical growth by Obesity level has important meaning to the health care and evaluation on adolescent girls. So this study tried to clear the relationship between weight and body fat by using data for the height, weight of 124 elementary school children and high school student in Seoul. Then this study tried to show the physical growth pattern and various characteristics by Obesity level by using longitudinal for the height, weight of 1113 high school students in Seoul, and it also tried to show what influencing factors on the physical growth of this aged population. The result could be summarized as follows. 1. The relationship between weight and body fat(%) has 0.81475(r) at age 9 and 0.69361(r) at age 18. Also the relationship between weight and lean body muscle(LBM %) has -0.81470(r) at age 9 and -0.64729(r) at age 18. 2. The weakness, normal and obesity groups were classified by Obesity level. In case of weakness group showed the very low Obesity level at age 8 to 11, in case of obesity group showed the high Obesity level at age 15 to 18. Also Rohrer index was decreasing tendency up to age 12 in weakness group and increasing tendency over age 14 in obesity group. 3. When the height and weight growth pattern was compared, height growth was superior to weight growth at age 9 to 14.5 in normal group. But weight growth was inferior to height growth at age 9 to 14.5 in normal group. In obesity group, weight growth was superior to height growth at age 7 to 18. On the other hand the height growth of weakness group was superior to the normal group and the obesity group except age 11 to 12. 4. On height velocity curve by PHV age obesity group showed the most growth amount per year(9.00Cm/yr), and the next is normal group(8.77Cm/yr), weakness group(8.70Cm/yr). Then the difference between PHV age and PWV age was within 1 year in these three groups. 5. In these three groups, height velocity curve by menarcheal age showed the PHV before 2~3 years of menarcheal age. And weight velocity curve by menarcheal age showed the remarkable PWV before 1 year of menarcheal age.

• Journal of the Korean Wood Science and Technology
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• v.46 no.6
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• pp.748-755
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• 2018

Timber from fast-growing tree species is susceptible to by biodeterioration attack, particularly subterranean termites. Impregnation with methyl methacrylate (MMA) potentially increases wood resistance to subterranean termite attack. Four wood species, namely sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), mangium (Acacia mangium), and pine (Pinus merkusii), were impregnated with MMA, and samples of untreated and imidacloprid-preserved wood were prepared for comparison purposes. Small stakes, sized 0.8 cm by 2 cm in cross section by 20 cm in the longitudinal direction, were inserted into the ground for 3 months, and the weight loss of each specimen was determined at the end of the test period. A factorial $4{\times}3$ completely randomized design was used for data analysis; the first factor was wood species, and the second factor was treatment. The results showed that MMA polymer loadings were 27.88%, 24.91%, 14.14%, and 17.81% for sengon, jabon, mangium, and pine, respectively, and amounts of imidacloprid retention were $7.56kg/m^3$, $5.98kg/m^3$, $5.34kg/m^3$, and $9.53kg/m^3$, respectively. According to an analysis of variance, wood species, treatment, and interaction of both factors significantly affected the weight loss of wood specimens. Mangium had the smallest weight loss, followed by pine, sengon, and jabon. MMA impregnation into the wood increased the resistance of wood samples to subterranean termite attack during in-ground testing, but the resistance level was lower than that of imidacloprid-preserved wood. Except for mangium wood, the MMA treatment did not significantly affect resistance.

• Korean Journal of Community Nutrition
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• v.17 no.3
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• pp.271-279
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• 2012

The prevalence of atopic dermatitis (AD) has increased recently all over the world. Several studies worldwide reported growth retardation associated with AD, but few studies were reported in Korea. Therefore, the objective of this study was to identity the differences in growth and nutrient intakes between Korean children with and without AD. The participants were 71 AD children and age, gender-matched 81 control children aged 10 to 36 months. Demographic information was gathered by questionnaires. Height and weight were measured at clinic and health centers. Height and weight for age, and weight for height were converted as deviation in Z scores using World Health Organization Standard. A 24 hour dietary recall method was performed to estimate nutrient intakes. A higher percentage of AD children had insufficient energy and intakes of calcium, phosphorus, iron, zinc and vitamin B2, defined as intakes lower than 75% of the Dietary Reference Intakes for Korean, compared to the control group (P < 0.001, P < 0.001, P = 0.003, P = 0.001, P = 0.014, P = 0.001, respectively). The percentages of children with height and weight for age Z score below than-1 (stunted) were significantly higher in the AD group (P < 0.001 and P < 0.001, respectively). Multiple food restriction, defined as ${\geq}$ 3 food elimination, was associated with insufficient energy and intakes of calcium, phosphorus, iron, zinc, vitamins A and B2. In conclusion, children with AD need regular nutrient assessment and education about alternative food choices to avoid r food elimination in order to prevent growth retardation or inadequate nutrient intakes. Further longitudinal studies for growth and nutrient intakes should be performed to understand the patterns of growth in children with AD.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.106-111
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• 2005

After many casualties of conventional bulk carriers in recent years, a double hull bulk carrier was proposed to enhance the structural safety of a side shell and a transverse bulkhead. In this paper, two alternative structural designs of a double hull bulk carrier were carried out based on the Lloyd's rule. One has the double sided hull with longitudinal stiffeners and the other has that with a girder. The final structural design was examined in comparison with an existing single hull bulk carrier from the viewpoints of cargo hold capacity and the increases of weight and construction cost. Generally, the construction cost of a ship consists of the costs of material, labor and overhead cost. But, in this study, the relative construction cost concept was introduced to compare the economical validity more precisely. In this concept, fixed overhead cost is excluded in the assessment of construction cost, and only the variable overhead cost is added up to labor cost. As the result of this study, a double hull bulk carrier can be constructed within 1% increase of weight and construction cost.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.2
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• pp.94-103
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• 1998

Recently, many researches are carried for high-speed and light craft. In this study, the optimum structural design procedure and the computer program are developed to minimize the hull weight of SES(Surface Effect Ship) built of composite materials. Three types of composite materials-Sandwich, Single Skin and Hybrid type- are considered and the efficiency of each type is investigated. In design process, the optimum design of main members is performed at first considering longitudinal strength. And then, the transverse member design is performed considering torsional strength SSDP(Structural Synthesis Design program) of U.S. Navy is adopted for design algorithm and DnV classification nile for design loads and strength criteria. For optimum structural design, ES 1+1 optimization technique is used.

• Journal of Nutrition and Health
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• v.28 no.8
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• pp.782-790
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• 1995

The longitudinal changes in protein secretion from 27 lactating women(primiparae = 10, multiparae=17) and protein intake of infants have been studied from 0.5 to 6 months postpartum in Chungju and Anseong area. The protein contents o breast milk in primiparae appeared significantly higher than in multipaae at 0.5 and 1 month postpartum. The protein secretion of primiparae and multiparae was not significantly different. In breast-feeding period, there was a tendency that protein secretion from 0.5 to 2 months postpartum was higher than thereafter. Average protein intake of boys from milk from 0.5 to 6 months postpartum was significantly higher than that of girls(p<0.05), because volume of milk intake of boys was much more than that of girls. In the amount of protein intake per infant weight, there was no significant difference between boys and girls. Protein intakes per infant weight decreased during lactation. Mean energy consumption of lactating women was 2,327㎉/day, which was 93.1% of recommended energy allowance for Koreans. Mean dietary protein consumption of lactating women was 81g/day, which was 101.3% of recemmended protein allowance for Koreans. Energy ratio of carbohydrate : protein : lipid was appeared to 68.8 : 13.9 : 17.3.