• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.865-870
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• 2001

An effective live load model for analyzing probable maximum live load effects in longitudinal direction such as moment and shear was developed. The main procedure of this live load model is composed of two parts. Firstly, determination of the appropriate influence lines, and secondly, application of the characteristics of vehicles and traffic patterns. Through this procedure, probabilistic distributions of maximum probable load effects are deduced in the form of probability density function (PDF) or cumulative density function (CDF). The proposed live load model is not limited by bridge types(number of spans or girders) and can consider local or global deterioration of bridges in the analysis. Besides, load effects can be determined at any section without restrictions.

• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2077-2082
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• 2015

Based on Deutsch assumption, a calculation method on the electric field over the ground surface under HVDC transmission lines in the wind is proposed. Analyzing the wind effects on the electric field and the space charge density the existing method based on Deutsch assumption is improved through adding the wind speed to the ion flow field equations. The programming details are illustrated. The calculation results at zero wind speed are compared with available data to validate the code program. Then the ionized fields which resulted from corona of ±800kV HVDC lines are analyzed. Both the electric field and the current density on the ground level are computed under different wind direction and speed. The computation results are in good agreement with measurements. The presented method and code program can be used to rapidly predict and evaluate the wind effects in HVDC transmission engineering.

• 소성∙가공
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• 제11권8호
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• pp.701-709
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• 2002

Aluminium foam material is highly porous material, which has the complicated cellular structure defined by randomly distributed pores in metallic matrix. This structure gives the characteristic properties which cannot be achieved by any other conventional processes. As the properties of aluminium foam material significantly depend on its porosity, a desired profile of properties can be tailored by changing the foam density. But various defects lead to undesirable effects on the mechanical properties. Mechanical properties are dependent on cell sizes and aspect ratios. Therefore, this paper presents the effects of various processing parameters of various parameters on the mechanical properties. For the sake of this, combined stirring was used to fabricate aluminum foam materials by the parameters. Compression and bending tests were performed to investigate the effects of cell sizes and aspect ratios on the mechanical properties.

• 아시안잔디학회지
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• 제7권1호
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• pp.13-18
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• 1993

Much attention has been given recently to solve the environmental contamination in golf courses Changing to culture practice rather than chemical practice that depends on pesticides and fertilizers is a hot issue in golf courses or grasslands. Organic soil conditioners improve soil-plant envirormental conditions rich in physical properties. In this study, measuring systems to evaluate soil conditioning effects were set up for on-site purpose. After establishing the methodology for evaluating soil conditioner effects, 2 kinds of organic conditioners were rested for examination. The systems for the methodology included a set of simulating equipment for field capacity, an impact type soil column compactor, and an infiltration-percolation system. Test results using the systems showed bulk density and infiltration rate of mixed soil were decreased at highter rates of conditioner, but total porocities were increased. Increased porocities were most capillary pore space which has a positive effect on soil water potential. The systems and methodology in this study seem to have an efficiency to measure the effects of soil conditioner on site purpose.

• Journal of Multimedia Information System
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• 제9권3호
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• pp.219-226
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• 2022

The advancement of realistic visual effects technology provides increasingly immersive experiences and consumer satisfaction with content. The explosion and destruction effects in live-action films and animations are some of the most frequently used visual effects, but they are relatively difficult to execute, so it is challenging to make them look realistic. This study tested a method of effectively realizing computer-generated explosions and destruction. Experiments for this study are as follows: first, the interlink according to density accumulation of the fluid; second, the interlink according to the temperature accumulation of the fluid; and third, the interlink according to the distance between the fluid and the involved objects. This study was conducted to identify an optimal solution for producing computer-generated explosions and destruction.

• 동의생리병리학회지
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• 제26권2호
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• pp.166-174
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• 2012

To determine the effects of Mahaengeuigam-tang(MHEGT) on obesity, the obesity-related factors (gastrin, CGRP, ghrelin, glucagon-like peptide-1, insulin, orexin, leptin, serotonin, NPY) were investigated in the stomach, pancreas, brain of mice by immunohistochemical methods for 4 weeks after Mahaengeuigam-tang(MHEGT) administration. The change of boy weight decreased in MHEGT administered group than that of control group. The immunohistochemical density of the gastrin and CGRP positive cells on pylorus of stomach increased in MHEGT administered group than that of control group. The number of ghrelin immunoreactive cells on stomach decreased in MHEGT administered groups than that of control group. The immunohistochemical density of GLP-1 in the pancreas decreased in MHEGT administered group than that of control group. The immunohistochemical density of insulin positive cells in the pancreas decreased in MHEGT administered group than that of control group. The immunohistochemical density of orexin and NPY positive neurons in the diencephalon was slightly stronger in MHEGT administered group than that of control group. The immunohistochemical density of serotonin and leptin positive neurons was stronger in MHEGT administered group than that of control group. These results demonstrate that Mahaengeuigam-tang(MHEGT) increased the immunohistochemical density of factors related to appetite inhibitors, and decreased the immunohistochemical density of factors related to stimulator of food intake in stomach, pancreas and brain.

• 대한기계학회논문집B
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• 제21권9호
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• pp.1165-1173
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• 1997

The steady state close-contact melting phenomenon occurring between a phase change material and an isothermally heated flat plate with relative motion is investigated analytically, in which the effects of vertical convection in the liquid film and solid-liquid density difference are incorporated simultaneously. Not only the scale analysis is conducted to estimate a priori qualitative dependence of system variables on characteristic parameters, but also an analytical solution to a set of simplified model equations is obtained to specify the effects under consideration. These two results are consistent with each other, in that the vertical convection affects both the solid descending velocity and the film thickness, and that the density difference alters only the solid descending velocity. While the effect of vertical convection can be characterized conveniently by a newly introduced temperature gradient factor which asymptotically approaches the unity/zero with decreasing/increasing the Stefan number, that of density difference is represented by the liquid-to-solid density ratio. It is shown that the solid descending velocity depends linearly on the density ratio, and that the ratios of solid descending velocity, film thickness and friction coefficient to the conduction solution are proportional to 3/4, 1/4 and -1/4 powers of the temperature gradient factor, respectively. Also, established is the fact that the effect of convection can be legitimately neglected in the analysis for the range of the Stefan number less than 0.1.

• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.57-63
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• 2015

Effects of rearing density on growth and survival of the polychaete rockworm Marphysa sanguinea have been investigated in order to develop rearing techniques for this species. This study was examined over a nine-month period in the Fisheries Science and Technology Center of Pukyong National University. Three rockworm densities, 500, 1,000 and $2,000worms{\cdot}m^{-2}$ with weight ranges of < 0.5 g, 0.6-1.5 g, and 1.6-2.5 g, and the no feed control treatment, were stocked in triplicate $0.10m^2$ boxes with sand bottoms. Growth rates were checked with 15 randomly sampled rockworms from each box at months 3, 6 and 9. Results showed that SGRs in all treatments were higher during the first period (0-3 months) than the second (3-6 months) and third periods (6-9 months) for all treatment densities, while SGRs decreased with increasing density. However, survival and growth of worms at high density was not better than low density, but daily biomass production in medium and high density groups was $6.28gm^{-2}day^{-1}$ for the rockworms of 0.6-1.5 g with $2,000inds{\cdot}m^{-2}$, and $12.6gm^{-2}day^{-1}$ for group between 1.6-2.5 g with $2,000inds{\cdot}m^{-2}$, and $14.7gm^{-2}day^{-1}$ for the group of individuals <0.5 g with $1,000inds{\cdot}m^{-2}$. Results showed that M. sanguinea can be one of the most suitable species to commercially exploit in a farming system. In particular, specified densities permit elevated pure production.

• 한국수산과학회지
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• 제44권1호
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• pp.58-63
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• 2011

This study investigated the effects of stocking density and feeding frequency (three and five times per week) on the growth of Pacific cod, Gadus macrocephalus. In the first experiment, experimental groups of fish (mean weight $167.8{\pm}41.4\;g$) were reared at three stocking densities (4, 8 and 12 kg/$m^3$) for 16 weeks. The total weight gain was 17.8, 17.1 and 35.4% at 4, 8 and 12 kg/$m^3$, respectively. The specific growth rates, survival rates and feeding efficiency increased with the density, but there were no significant differences (P>0.05). The daily feed intake decreased as the stocking density increased, whereas the condition factors increased with the stocking density (P<0.05). In the second experiment, groups of fish ($194.1{\pm}68.3\;g$) were fed either three or five times a week. The total wight gain was 14.4 and 18.5% for the fish fed three and five times per week, respectively. The specific growth rates of Pacific cod fed to satiation increased with the feeding frequency, although the difference was not significant (P>0.05). The survival rates, daily feed intake, feed efficiency, and condition factors of the Pacific cod were not significantly different (P>0.05). Based on these results, the optimum stocking density for juvenile cod is above 12 kg/$m^3$, and the best feeding frequency is three times a week, under the conditions used in this experiment.

• Nutrition Research and Practice
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• 제4권5호
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• pp.414-420
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• 2010

This study examines the combined effects of caloric restriction on body composition, blood lipid, and satiety in slightly overweight women by varying food density and aerobic exercise. Twenty-three women were randomly assigned to one of two groups for a four-week weight management program: the high-energy density diet plus exercise (HDE: n = 12, $22{\pm}2$ yrs, $65{\pm}7$ kg, $164{\pm}5$ cm, $35{\pm}4%$ fat) and low-energy density diet plus exercise (LDE: n = 11, $22{\pm}1$ yrs, $67{\pm}7$ kg, $161{\pm}2$ cm, $35{\pm}4%$ fat) groups. Subjects maintained a low-calorie diet (1,500 kcal/day) during the program. Isocaloric ($483{\pm}26$ for HDE, $487{\pm}27$ kcal for LDE) but different weight ($365{\pm}68$ for HDE, $814{\pm}202$ g for LDE) of lunch was provided. After lunch, they biked at 60% of maximum capacity for 40 minutes, five times per week. The hunger level was scaled (1: extremely hungry; 9: extremely full) at 17:30 each day. Before and after the program, the subjects' physical characteristics were measured, and fasting blood samples were drawn. The daily energy intake was $1,551{\pm}259$ for HDE and $1,404{\pm}150$ kcal for LDE (P > 0.05). After four weeks, the subjects' weights and % fat decreased for both LDE (-1.9 kg and -1.5%, P < 0.05) and HDE (-1.6 kg and -1.4%, respectively, P < 0.05). The hunger level was significantly higher for HDE ($2.46{\pm}0.28$) than for LDE ($3.10{\pm}0.26$) (P < 0.05). The results suggest that a low-energy density diet is more likely to be tolerated than a high-energy density diet for a weight management program combining a low-calorie diet and exercise, mainly because of a reduced hunger sensation.