• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.163-170
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• 2008

According to the rules, a crash cushion is supposed to set up products that is satisfied with the standard of a performance test after performing the car crash test by road safety facilities and management guide. For development of crash cushion, performance should be estimated through the car crash test eventually. However, there is no reasonable design method which considers passenger's safety and only depend on crash test without an alternative plan. Therefore it incurs a loss materially and takes a lot. Therefore, we are asked to create a systematic design of the crash cushion. This study shows that a scientific basis of applying single degree of freedom when it designs the crash cushion after analyzing vehicle crash test data of crash cushion and also represents design of crash cushion through single degree of freedom response spectrum using calculated by crash test data on crash cushion.

• Steel and Composite Structures
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• v.49 no.2
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• pp.245-255
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• 2023

The present paper summarizes the results of an experimental program on the influence of using waste lathe scraps in the concrete mixture on the shear behavior of RC beams with different amounts of shear reinforcement. Three different volumetric ratios (1, 2 and %3) for the scraps and three different stirrup spacings (160, 200 and 270 mm) were adopted in the tests. The shear span-to-depth ratios of the beams were 2.67 and the stirrup spacing exceeded the maximum spacing limit in the building codes to unfold the contribution of lathe scraps to the shear resistances of shear-deficient beams, subject to shear-dominated failure (shear-tension). The experiments depicted that the lathe scraps have a pronounced contribution to the shear strength and load-deflection behavior of RC beams with widely-spaced stirrups. Namely, with the addition of 1%, 2% and 3% waste lathe scraps, the load-bearing capacity escalated by 9.1%, 21.8% and 32.8%, respectively, compared to the reference beam. On the other hand, the contribution of the lathe scraps to the load capacity decreases with decreasing stirrup spacing, since the closely-spaced stirrups bear the shear stresses and render the contribution of the scraps to shear resistance insignificant. The load capacity, deformation ductility index (DDI) and modulus of toughness (MOT) values of the beams were shown to increase with the volumetric fraction of scraps if the stirrups are spaced at about two times the beam depth. For the specimens with a stirrup spacing of about the beam depth, the scraps were found to have no considerable contribution to the load capacity and the deformation capacity beyond the ultimate load. In other words, for lathe scrap contents of 1-3%, the DDI values increased by 5-23% and the MOT values by 63.5-165% with respect to the reference beam with a stirrup spacing of 270 mm. The influence of the lathe scraps to the DDI and MOT values were rather limited and even sometimes negative for the stirrup spacing values of 160 and 200 mm.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.3
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• pp.18-32
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• 2024

This study aims to analyze the summer human thermal environment in Jeju City's outdoor parking lots by measuring microclimate data and comparing pavement and vegetation albedoes and elements through computer simulations. In measured cases, results due to albedo showed no significance, but there was a significant difference between sunny and shaded areas by trees. The sunny area had a PET (physiological equivalent temperature) in the 'very hot' level, while the shaded area exhibited a 2-step lower 'warm' level. UTCI (universal thermal climate index) also showed that the sunny area was in the 'very strong heat stress' level, whereas the shaded area was 1-step lower in the 'strong heat stress' level, confirming the role of trees in reducing incoming solar radiant energy. Simulation results, using the measured albedoes, closely resembled the measured results. Regarding vegetation, scenarios with a wide canopy, high leaf density, and narrow planting spacing were effective in mitigating the human thermal environment, and the differences due to tree height varied across scenarios. The scenario with the lowest PET value was H9W9L3D8 (tree height 9m, canopy width 9m, leaf area index 3.0, planting spacing 8m), indicating a 0.7-step decrease compared to the current landscaping scenario. Thus, it was confirmed that, among landscaping elements, trees have a significant impact on the summer human thermal environment compared to ground pavement.

• Korean Journal of Poultry Science
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• v.6 no.1
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• pp.12-23
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• 1979

This experiment was carrid out to investigate the interaction between boilelr strains and nutrition levels, and the performances of four broiler strains such as Han Hyup 603, Hubbard, Anak and Filch when they were fed by four different nutrition levels (High Protein and energy; HP. HE., Medium Protein and energy; MP. ME., Low Protein ana energy; LP. LE., and low protein and energy; LLP. LLE.). The data used in this study were obtained from a total of 1200 broiler type chicks in Poultry Testing Station, Korean Poultry Association from June 16, to August 11, 1978. Differences of all characters among four nutrition levels were significant except viability and carcass rate. HP. HE and MP. ME treatments showed nearly the same performances in body weight, feed efficiency and point, spread but they were significantly superior to those of LP. LE and LLP. LLE. There were not significant differences among four strains in feed efficiency and viability but other characters, body weight, point spread and carcass rate were observed that the performance of the best strain B was significantly superior to strain D but it was not recognized significance compared with strain A, C in tile result of statisticel analysis. In the interaction between strains and nutrition levels, body weight at high and levels showed significantly differences but at low and low nutrition levels were nearly same among four strains. Therefore this study demonstrated that comparision of body weights between strains should be performed at medium nutrition level or above. Also point spread calculated as index of body weight and feed efficiency was observed that strain B at low nutrition level is excellently higher than other strains and there were little differences at low nutrition level among all strains. It was found that ]it tie differences between performances of high arid medium levels seemed to be as the reason of high fat addition for energy source to high mutrition feed, and in general superior strain showed good performance at all the nutrition levels in$.$all characters but in body weight and point spread there were significantly different responses with different nutrition level, The most superior strain B among four strains earned the most profit per bird, Although performances of high and medium nutrition levels were nearly the same, medium nutrition level also showed the most profit because the feed cost of high nutrition level was higher than that of medium nutrition level.

• Journal of Nutrition and Health
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• v.34 no.6
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• pp.637-644
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• 2001

The purpose of this study was to examine the effect of exercise and diet control program on nitrogen balance in obese children. The subjects of this study were five obese boys aged from 8 to 12 participating in the control period(C) for 3 days, exercise without energy deficit period(EEN) for one week, and exercise with energy deficit period(EED) far another one week, consecutively. The intensity of the exercise was 60-70% of HRmax and the energy was restricted at 493 kcal/day. Daily mean total energy intake was 2,152 $\pm$ 138kca1, 1,861 $\pm$ 138kca1, and 1,368 $\pm$ 87kca1 for the period C, EEN and EED, respectively. The body weight for EEN and EED decreased compared with the period C by average 1.2 $\pm$ 0.2kg and 1.8 $\pm$ 0.3kg, respectively. Of the body weight loss, the fat mass decreased bur 1.0 $\pm$ 0.3kg and 1.5 $\pm$ 0.5kg and the lean body mass by 0.2 $\pm$ 0.4kg and 0.3 $\pm$ 0.4kg, respectively. Of the daily mean nitrogen consumption was 9.1 $\pm$ 0.7g, 9.1 $\pm$ 0.8g and 7.1 $\pm$ 0.5g, the daily mean nitrogen excretion from feces was 1.3 $\pm$ 0.2g, 0.9 $\pm$ 0.1g and 0.7 $\pm$ 0.1g, and from urine was 6.7 $\pm$ 0.6g, 6.6 $\pm$ 0.5g and 6.7 $\pm$ 0.6g, for the period C, EEN and EED, respectively. Daily mean nitrogen balance excluding nitrogen excretion firm feces and urine indicated + 1.1 $\pm$ 1.0, +1.6 $\pm$ 0.6 and - 0.3 $\pm$ 0.9 for the period C, EEN and EED, respectively. Despite the negative indication during EED, there was no statistical signifiranre. The daily mean creatinine excretion was 0.5 $\pm$ 0.0g, 0.7 $\pm$ 0.1g and 0.6 $\pm$ 0.0g and the creatinine-height index(CHl) was 85.1 $\pm$ 6.7%, 83.8 $\pm$ 6.6% and 81.0 $\pm$ 6.5%, for the period C, EEN and EED, respectively, indicating little significant difference among the periods. Taking above results into consideration, it seems the exercise program conducted for this study did not substantially affect the nitrogen balance of the obese children, and may be used far the body weight control. Howeever, the adequacy of the energy restriction and amount of exercise applied to this study need to be further investigated as the nitrogen balance indicated negative and increasing tendency of the creatinine excretion showed during the EED compared with period C, despite the statistical insignificance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.948-957
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• 2016

We previously developed an herbal composition (HemoHIM) based on the water extracts of Angelica gigas radix, Cnidium officinale rhizoma, and Paeonia japonica radix to protect and recover hematopoietic and intestinal tissues against radiation injuries. In this study, to develop a composition with improved activities based on enhanced fat-soluble polyphenol contents, we prepared a new herbal composition, MH-30, from the above three herbs by 30% ethanol extraction and hot water extraction. HPLC analysis of the ethanol fractions of MH-30 and HemoHIM revealed that MH-30 had higher contents of many fat-soluble polyphenol compounds than HemoHIM (8.7-fold increase for decursin), whereas contents of water-soluble polyphenol compounds showed little differences between the two compositions. Then, we evaluated MH-30 and HemoHIM for their in vitro antioxidant and immune cell-stimulating activities as well as in vivo protective effects against radiation injuries in hematopoietic and self-renewal tissues. In antioxidant activity assays, MH-30 showed higher hydroxyl radical scavenging activity than HemoHIM (1.4- to 1.9-fold for compositions and 2.3- to 4.5-fold for ethanol fractions). On the other hand, MH-30 and HemoHIM exhibited similar immune cell-stimulating activities as measured by in vitro lymphocyte proliferation. MH-30 increased endogenous spleen colony formation, decreased bone marrow cell apoptosis, and enhanced survival of intestinal crypts in irradiated mice, demonstrating effective protection of MH-30 against radiation-induced injuries in hematopoietic and self-renewal tissues. The 30-day survival rate of lethally irradiated mice, a comprehensive index for radioprotective efficacy, was also elevated by MH-30. Noticeably, MH-30 showed higher protective effects than HemoHIM in all mouse experiments. These results demonstrate that MH-30 can protect hematopoietic and self-renewal tissues against radiation injuries more effectively than HemoHIM. Therefore, MH-30 can be a good candidate to reduce radiation injuries in hematopoietic and self-renewal tissues incurred by radiation accidents or cancer radiation therapy.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.187-194
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• 2011

In compliance with an international law about the ocean dumping of the sludge, the proper sewage treatment process which occurs from the wastewater treatment process has been becoming problem. Generally the sewage and the sludge are controlled from anaerobic condition when the sewage is treated and land filled, where the methane$(CH_{4})$ and the nitrous oxide $(N_{2}O)$ from this process are discharged. Because these gases have been known as one of the responsible gases for global warming, the wastewater treatment process is become known as emission sources of green house gases(GHG). This study is to suggest a new approach of estimate and environmental assessment of greenhouse gas emissions and sludge emissions from wastewater treatment processes. It was carried out by calculating the total amounts of GHG emitted from biological wastewater treatment process and the amount of the sludgegenerated from the processes. Four major biological wastewater treatment processes which are Anaerobic/Anoxic/Oxidation$(A_{2}O)$, Bardenpho, Virginia Initiative Plant(VIP), University of Cape Town(UCT)are used and GPS-X software is used to model four processes. Based on the modeling result of four processes, the amounts of GHG emissions and the sludge produced from each process are calculated by Intergovernmental Panel on Climate Change(IPCC) 2006 guideline report. GHG emissions for water as well as sludge treatment processes are calculated for environmental assessment has been done on the scenario of various sludge treatments, such as composting, incineration and reclamation and each scenario is compared by using a unified index of the economic and environmental assessment. It was found that Bardenpho process among these processes shows a best process that can emit minimum amount of GHG with lowest impact on environment and composting emits the minimum amount of GHG for sludge treatment.

• The Korean Journal of Food And Nutrition
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• v.16 no.3
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• pp.197-202
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• 2003

The purpose of this study was to investigate basic factors of obesity, nutrient intakes, behaviors of dietary life, daily energy expenditure and emphasize on the necessity of school education. Because the growing prevalence of obesity have required a need for health education in school. The results were as follows. 1. The average height of boys and girls was l59${\pm}$13cm(boys), l54${\pm}$11cm(girls). The average weight of them was 68${\pm}$16kg(boys), 70${\pm}$13kg(girls). BMI(body mass index) of them was 26.9${\pm}$3.4(boys), 29.5${\pm}$2.9(girls). 2. For energy and protein, the average intakes of subjects were higher than recommended dietary allowances for Koreans(7th Ed). The average intakes of vitamin A and ascorbic acid were much lower than the recommended dietary allowances. 3. Most of subjects prefer fast food, rich snacks and overeating, irregular meal amount and these dietary behaviors were severe problems. 4. Total energy expenditure was 1,933kcal in boys and 1,789kcal in girls. To reduce weight and treat obesity, the required energy intake to subjects was 1,546kcal(boys) and 1,431kcal(girls). If we prepared the effective program for obesity, school education should be integrated within the larger community. Parents of students and students may be educated to make good health changes in the home. Nutrition education has a direct impact on their life style of their food intake and nutritional status. The use of multi-component obesity treatments will be effective in a school setting. It is more effective to encourage health habits in school, house and it should be integrated within the larger community.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.419-428
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• 2021

In order to develope a mobile-based greenhouse energy calculation program, firstly, the overall thermal transmittance of 10 types of major covers and 16 types of insulation materials were measured. In addition, to estimate the overall thermal transmittance when the cover and insulation materials were installed in double or triple layers, 24 combinations of double installations and 59 combinations of triple installations were measured using the hotbox. Also, the overall thermal transmittance value for a single material and the thermal resistance value were used to calculate the overall thermal transmittance value at the time of multi-layer installation of covering and insulating materials, and the linear regression equation was derived to correct the error with the measured values. As a result of developing the model for estimating thermal transmittance when installing multiple layers of coverings and insulating materials based on the value of overall thermal transmittance of a single-material, the model evaluation index was 0.90 (good when it is 0.5 or more), indicating that the estimated value was very close to the actual value. In addition, as a result of the on-site test, it was evaluated that the estimated heat saving rate was smaller than the actual value with a relative error of 2%. Based on these results, a mobile-based greenhouse energy calculation program was developed that was implemented as an HTML5 standard web-based mobile web application and was designed to work with various mobile device and PC browsers with N-Screen support. It had functions to provides the overall thermal transmittance(heating load coefficient) for each combination of greenhouse coverings and thermal insulation materials and to evaluate the energy consumption during a specific period of the target greenhouse. It was estimated that an energy-saving greenhouse design would be possible with the optimal selection of coverings and insulation materials according to the region and shape of the greenhouse.

• The Journal of Engineering Geology
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• v.24 no.2
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• pp.247-260
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• 2014

Rock masses at the site for the $2^{nd}$ step construction of the KAERI Underground Research Tunnel (KURT) are divided into six units to establish a rock mechanics model that is dependent on the geological characteristics and degree of joint development. The site primarily consists of three granitic units (G1, G2, and G3), two dykes (D1 and D3), and a fault zone of poor rock mass quality (F3). The F3 unit crosses the tunnel at the beginning of the site of $2^{nd}$ step construction. The rock masses of each unit are classified by RMR (Rock Mass Rating), Q-system, and RMi (Rock Mass Index), all based on borehole logging data. The deformation modulus, rock mass strength, cohesion, and friction angle for each unit are calculated using established empirical relationships. The representative rock mass classification and geotechnical parameters for the rock mass units are established, and a rock mechanics model for the site is proposed, which will be useful in the design and stability analysis of the $2^{nd}$ step construction of KURT.