• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.223-231
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• 2012

The purpose of this study is to investigate basically the mechanism of heat transfer by the resolution of complex fluid flow inside a sophisticated designed screw dryer for the treatment of sewage sludge by using numerical analysis and experimental study. By doing this, the result was quite helpful to obtain the design criteria for enhancing drying efficiency, thereby achieving the optimal design of a multiple screw type dryer for treating inorganic and organic sludge wastes. One notable design feature of the dryer was to bypass a certain of fraction of the hot combustion gases into the bottom of the screw cylinder, by the fluid flow induction, across the delicately designed holes on the screw surface to agitate internally the sticky sludges. This offers many benefits not only in the enhancement of thermal efficiency even for the high viscosity material but also greater flexibility in the application of system design and operation. However, one careful precaution was made in operation in that when distributing the hot flue gas over the lump of sludge for internal agitation not to make any pore blocking and to avoid too much pressure drop caused by inertial resistance across the lump of sludge. The optimal retention time for rotating the screw at 1 rpm in order to treat 200 kg/hr of sewage sludge was determined empirically about 100 minutes. The corresponding optimal heat source was found to be 150,000 kcal/hr. A series of numerical calculation is performed to resolve flow characteristics in order to assist in the system design as function of important system and operational variables. The numerical calculation is successfully evaluated against experimental temperature profile and flow field characteristics. In general, the calculation results are physically reasonable and consistent in parametric study. In further studies, more quantitative data analyses such as pressure drop across the type and loading of drying sludge will be made for the system evaluation in experiment and calculation.

• Journal of Nutrition and Health
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• v.48 no.3
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• pp.258-268
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• 2015

Purpose: The aim of this study was to explore the relationship of ready-to-eat cereal (RTEC) consumption with nutrition and health status. Examination of health status for this project included obesity, abdominal obesity, hypertension, hypertriglyceridemia, hypercholesterolemia, low-HDL-cholesterolemia, diabetes, anemia, and metabolic syndrome. Methods: Two groups, RTEC consumers and those who did not consume RTEC, were identified using 24-hour dietary recall data from the 2012 Korea National Health and Nutrition Examination Survey (KNHANES). Nutritional intakes and risk factors of the two groups were compared using covariates-adjusted statistical procedures. Statistical analyses were performed using SAS survey procedures, and strata, cluster, and weight were considered. Subjects of analysis of nutritional intake were between the ages of 1 and 75, and those considered in the risk factor analysis were between the ages of 19 and 75. Results: Results showed that 3.8% of the Korean population was RTEC consumers. Compared to the subjects who did not intake RTEC, RTEC consumers exhibited significantly higher intakes of calcium, thiamin, riboflavin, and vitamin C. It was also discovered that the percentage of people whose intakes were less than EAR decreased with RTEC consumption. RTEC consumption showed significant association with decreased systolic blood pressure, diastolic blood pressure, serum triglyceride, and serum total cholesterol. Consequently, prevalence of hypertension among RTEC consumers was significantly lower than that among non-consumers, and the odds ratio for hypertension was 0.19 after adjusting the models for covariates. Conclusion: Results of this study clearly suggest an association of RTEC consumption with improved nutritional status and cardiometabolic risk profile in Korean adults. Conduct of additional studies will be necessary in order to determine the nature of these relationships.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.105-110
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• 2009

The effects of heat treated and herb added garlic (Allium sativum L.) on the antioxidant activities were investigated. Boiling ($100^{\circ}C$, 60 min), steaming ($100^{\circ}C$, 30 min), baking ($120^{\circ}C$, 10 min), or high temperature and high pressure (HTHP, $120^{\circ}C$, 20 min, 1.5 kgf/$cm^2$) were applied, and several herbs were added to garlic. Hunter color L-value of heated garlic was significantly decreased, compared to that of control (fresh garlic), whereas a-value and b-value were increased (p<0.05). In the texture profile analysis, hardness, chewiness and gumminess of heated garlic were decreased, whereas adhesiveness was increased. The antioxidant activities determined by DPPH and hydroxyl radical scavenging activities were decreased in HTHP garlic. The pungent taste and garlic odor were the weakest in HTHP garlic. Especially, the pungent taste of HTHP garlic was not detectable. Green tea among several herbs (bay leaf, cinnamon bark, pine needles) showed the highest DPPH radical scavenging activity. Addition of green tea to HTHP garlic was appropriate for decreasing antioxidative activity of HTHP garlic compared to fresh garlic. Based on these results, it was suggested that high temperature and high pressure treated garlic with green tea might be very useful as a substitute for odorless functional garlic products.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.160-168
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• 2008

Purpose: This study was designed to characterize the nutritional status and assess obesity to determine the relationship between obesity and serum lipid profiles in 6~7 year old children. Methods: In 2007, we surveyed 483 children (233 boys and 250 girls) aged 6~7 years. The total cholesterol, triglyceride levels and HDL-cholesterol were measured in the fasting state. Dietary information was obtained by a questionnaire. Results: The prevalence of obesity was 9.9%. There was no significant difference between genders. The mean caloric intake was 1,781 kcal in boys and 1,640 kcal in girls. The prevalence of excessive calories was 33% in boys and 30% in girls. The prevalence of a total cholesterol ${\geq}$200 mg/dL was 8.4%, TG ${\geq}$130 mg/dL was 5.0%, LDL-cholesterol ${\geq}$130 mg/dL was 3.1%, and HDL-cholesterol <35 mg/dL was 4.4%. The prevalence of hypertension was 2.1%. There was no significant difference between genders. The systolic blood pressure, triglyceride levels and LDL-cholesterol were significantly related to an increased obesity index (p<0.05). The mean caloric intake and nutritive component were not related to the obesity index. The obesity group was compared to the control group: for triglycerides ${\geq}$130 mg/dL the odds ratio was 4.08; for LDL-cholesterol ${\geq}$130 mg the odds ratio was 2.85; for a TC/HDL-cholesterol ${\geq}$4.0 the odds ratio was 1.16. The BMI and triglyceride levels in the group with hypertension were higher than control group (p<0.05). There were significant positive correlations between the BMI and blood pressure as well as the LDL-cholesterol and triglycerides (p<0.05). The BMI was not correlated with the mean caloric intake or nutrition. Conclusion: The prevalence of hypertension and hyperlipidemia in 6~7 year old children was significantly related to an increased obesity index. The management of obesity in 6~7 year old children should include a reduction in the risk for hyperlipidemia and hypertension.

• Journal of Life Science
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• v.19 no.12
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• pp.1750-1757
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• 2009

The purpose of this study was to investigate the effects of regular walking exercise on health-related parameters in the elderly with chronic diseases - apoplexy, overweight, impaired fasting glucose, and overweight + impaired fasting glucose. A total of 85 subjects, 27, 17, 21 and 20 in apoplexy (A), overweight (O), impaired fasting glucose (IFG), overweight + impaired fasting glucose group (O_IFG), respectively, completed a 12-week walking exercise. The health-related parameters were measured before and at the completion of the exercise program including anthropometric measurements, functional physical fitness levels, blood pressure, fasting glucose, blood lipid profiles and chronic inflammatory markers (CRPs). Significant improvements in body weight, BMI, %body fat, blood pressure, all blood lipid measurements and all measured physical fitness items were shown in A; those in %body fat, TC, HDL-C and LDL-C in O; those in body weight, BMI, %body fat, fasting glucose, TC, TG and HDL-C in IFG; and those in body weight, HDL-C and LDL-C in O_IFG (p<0.05). The results of the present study demonstrated that a 12-week walking exercise brought positive effects on body weight, bloody lipid profiles, fasting glucose and functional physical fitness levels in the elderly with chronic diseases. In conclusion, this study suggested that walking regularly is very effective in lowering the risks of developing chronic diseases.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.57-70
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• 2009

Considerable advance has been made on research on effect of steel pipe Umbrella Arch Method (UAM) and mechanical reinforcement mechanism through numerical analyses and experiments. Due to long analysis time of three-dimensional analysis and its complexity, un-quantitative two-dimensional analysis is dominantly used in the design and application, where equivalent material properties of UAM reinforced area and ground are used, For this reason, development of reasonable, theoretical, quantitative and easy to use design and analysis method is required. In this study, both field UAM tests and laboratory tests were performed in the residual soil to highly weathered rock; field tests to observe the range of reinforcement, and laboratory tests to investigate the change of material properties between prior to and after UAM reinforcement. It has been observed that the increase in material property of neighboring ground is negligible, and that only stiffness of steel pipe and cement column formed inside the steel pipe and the gap between steel pipe and borehole contributes to ground reinforcement. Based on these results and concept of Convergence Confinement Method (CCM), two dimensional axisymmetric analyses have been performed to obtain the longitudinal displacement profile (LDP) corresponding to arching effect of tunnel face, UAM effect and effect of supports. In addition, modified load distribution method in two dimensional plane-strain analysis has been suggested, in which effect of UAM is transformed to internal pressure and modified load distribution ratios are suggested. Comparison between the modified method and conventional method shows that larger displacement occur in the conventional method than that in the modified method although it may be different depending on ground condition, depth and size of tunnel, types of steel pipe and initial stress state. Consequently, it can be concluded that the effect of UAM as a beam in a longitudinal direction is not considered properly in the conventional method.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.5
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• pp.335-347
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• 2013

In February 2008, high storm waves due to a developed atmospheric low pressure system propagating from the west off Hokkaido, Japan, to the south and southwest throughout the East Sea (ES) caused extensive damages along the central coast of Japan and along the east coast of Korea. This study consists of two parts. In the first part, we estimate extreme storm wave characteristics in the Toyama Bay where heavy coastal damages occurred, using a non-hydrostatic meteorological model and a spectral wave model by considering the extreme conditions for two factors for wind wave growth, such as wind intensity and duration. The estimated extreme significant wave height and corresponding wave period were 6.78 m and 18.28 sec, respectively, at the Fushiki Toyama. In the second part, we perform numerical experiments on wave-structure interaction in the Fushiki Port, Toyama Bay, where the long North-Breakwater was heavily damaged by the storm waves in February 2008. The experiments are conducted using a non-linear shallow-water equation model with adaptive mesh refinement (AMR) and wet-dry scheme. The estimated extreme storm waves of 6.78 m and 18.28 sec are used for incident wave profile. The results show that the Fushiki Port would be overtopped and flooded by extreme storm waves if the North-Breakwater does not function properly after being damaged. Also the storm waves would overtop seawalls and sidewalls of the Manyou Pier behind the North-Breakwater. The results also depict that refined meshes by AMR method with wet-dry scheme applied capture the coastline and coastal structure well while keeping the computational load efficiently.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.93-100
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• 2011

Maintenance of adequate soil water potential during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement within and below the rooting zone can facilitate optimal irrigation scheduling aimed at minimizing the adverse effects of water stress on crop growth and development and the leaching of water below the root zone which can have adverse environmental effects. The objective of this study was to evaluate the feasibility of using a portable irrigation controller with an Watermark sensor for the cultivation of drip-irrigated vegetable crops in a greenhouse. The control capability of the irrigation controller for a soil water potential of -20 kPa was evaluated under summer conditions by cultivating 45-day-old tomato plants grown in three differently textured soils (sandy loam, loam, and loamy sands). Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30 cm depths. Even though a repeatable cycling of soil water potential occurred for the potential treatment, the lower limit of the Watermark (about 0 kPa) obtained in this study presented a limitation of using the Watermark sensor for optimal irrigation of tomato plants where -20 kPa was used as a point for triggering irrigations. This problem might be related to the slow response time and inadequate soil-sensor interface of the Watermark sensor as compared to a porous and ceramic cup-based tensiometer with a sensitive pressure transducer. In addition, the irrigation time of 50 to 60 min at each of the irrigation operation gave a rapid drop of the potential to zero, resulting in over irrigation of tomatoes. There were differences in water content among the three different soil types under the variable rate irrigation, showing a range of water contents of 16 to 24%, 17 to 28%, and 24 to 32% for loamy sand, sandy loam, and loam soils, respectively. The greatest rate increase in water content was observed in the top of 10 cm depth of sandy loam soil within almost 60 min from the start of irrigation.

• Journal of Nutrition and Health
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• v.40 no.5
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• pp.451-462
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• 2007

This study was conducted to investigate breakfast consumption pattern in relation to diet quality and health outcomes of Korean adults. Data are from 2001 National Health and Nutrition Survey. Dietary information of 3406 adults aged $30{\sim}49$ years and their socio-demographic characteristics, blood lipid profile, fasting blood glucose, blood pressure, anthropometric measurements were analyzed. According to the breakfast consumption of the subjects, they were classified to breakfast skippers and eaters and the eaters' breakfast staple types were defined as RICE, BREAD, NOODLES, MIXED (mixed types including several grain-based dishes), and OTHERS. The proportions of breakfast consumption patterns were 18.4% for skippers, 71.1% for RICE, 2.6% for BREAD, 1.6% for NOODLES, 4.0% for MIXED, and 2.4% for OTHERS. Breakfast skippers had lower daily nutrients intake than breakfast eaters but their health outcomes did not differ from those of eaters. Instead, men with BREAD pattern had higher blood cholesterol and women in NOODLE pattern had higher blood glucose and lower HDL cholesterol. The BREAD pattern breakfast had higher energy contribution from fat and lower nutrient densities and the subjects in BREAD pattern had higher level of household income. Men's BREAD pattern breakfast consisted more animal products than that of women. There was high probability of undernutrition among women in NOODLE pattern and their mean household income was the lowest. From these results, in Korea, breakfast staple types have different food patterns and there was need for developing healthy food patterns appropriate to each staple type. The breakfast consumption pattern had influences on nutrient adequacy of the diet and health outcomes and seemed to represent socio-economic status. These could be used in doing nutrition education in community.

• Clinical and Experimental Pediatrics
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• v.50 no.10
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• pp.987-994
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• 2007

Purpose : This study investigated the clinical significance of AN in children and adolescents with obesity induced metabolic complications. Methods : Forty-nine patients who had obesity induced metabolic complications were participated in this cross-sectional study. Obesity induced metabolic complications are as follows: hypertension, dyslipidemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), nonalcoholic steatohepatitis (NASH), homeostasis model assessment of insulin resistance (HOMA-IR)>3.16. Clinical characteristics, such as, age, percentage-weight-for-height (PWH), pubertal status, blood pressure (BP), fasting plasma insulin level, fasting and post-oral glucose tolerance test 2-hour glucose levels, liver function test, lipid profile, HOMA-IR were compared according to the presence of AN. Results : Sixty-five percent of patients had AN, 57.1% NASH, 57.1% dyslipidemia, 55.1% hypertension, 46.9% IFG, 24.5% HOMA-IR>3.16 and 16.2% IGT. The patients who were moderately to severely obese with AN had higher incidence of IGT and HOMA-IR>3.16. The patients with AN had significantly higher diastolic BP ($79.4{\pm}6.9$ vs $75.4{\pm}5.6mmHg$), fasting levels of plasma insulin ($10.6{\pm}6.0$ vs $6.2{\pm}5.4{\mu}IU/mL$), HOMA-IR index ($2.6{\pm}1.4$ vs $1.4{\pm}1.3$) and PWH ($42.4{\pm}13.0$ vs $34.3{\pm}1.8%$). The increasing tendency for the presence of AN was significantly related to the cumulative number of obesity induced metabolic complications. Binary logistic regression analysis revealed that the presence of AN was significantly associated with fasting plasma insulin level, PWH and IFG. Conclusion : AN could be useful as a clinical surrogate of obesity induced metabolic complications.