• KIEAE Journal
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• v.16 no.3
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• pp.95-101
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• 2016

Purpose: Recently, high-rise buildings are popular in korea due to high rate of land usage and cost performance in urban area. However, high-rise building causes several problems such as safety issues, cooling/heating load, stack effect, disaster prevention etc. The stack effect is one of the representative problems. Even though there are many researches on stack effect, there are few studies on design guideline considering local condition. Method: This study focuses on the change of pressure distribution according to the design factors which affects the airflow in high-rise residential buildings by simulation analysis. In this study, city, building floor, stairwell door leakage area, elevator door leakage area and changes of layout were considered ad the design factor. Result: The simulation results indicate that building height and ambient air temperature are significant design factor for stack effect.

• The Journal of Internal Korean Medicine
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• v.33 no.1
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• pp.26-38
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• 2012

Objectives : The aim of this study was to investigate the effect of partial pyloric obstruction on body weight, gastric juice, gastric surface area and gastric edema in normal intact and/or vagotomized rats. Methods : Partial pyloric obstruction was performed by wrapping a non-absorbable rubber ring (D:6 mm, W:4 mm, T:1 mm) around the 1st portion of the duodenum. Vagotomy was performed by resecting the branches around the esophagogastric junction. Pre-post body weight differential, fasting gastric juice volume, gastric surface area and gastric edema were measured at 8 weeks and 20 weeks. For the effect of pyloric reperfusion the rubber ring was removed after 8 weeks and then an additional 12 weeks of observation was performed to the end of the 20-week experimental period. Results : In the initial 8 weeks observation, the effect of pylorus obstruction and/or vagotomy was significantly remarkable in the pylorus obstructed and vagotomized group; slowdown of weight gain, increase of fasting gastric juice volume, dilatation of gastric surface area and severe gastric edema were shown. In the remaining 12 weeks observation, the effect of reperfusion was significantly remarkable in the ring-removed antral dilated group; recovery of weight gain, decrease of gastric surface area and decrease of gastric edema were shown. However, gastric juice volume was not significantly different from the other group. Conclusions : Partial pyloric obstruction plays a aggravating role and the vagus nerve plays a protective role in body weight, gastric juice, gastric surface area, and gastric edema. Furthermore, pyloric valve dysfunction as an aggravating factor strengthened in defect of the vagus nerve. These results suggest that patients with both functional pyloric outlet obstruction and hypofunction of vagus nerve need to be diagnosed in good time and treated properly.

• Journal of dental hygiene science
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• v.22 no.4
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• pp.199-205
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• 2022

Background: The use of dental floss is associated with a reduction in dental caries and periodontal disease. According to personal preference, not only thread type but also C type and Y type floss are used. Although the effectiveness of dental floss for removing dental plaque has been proven, plaque removal effect of C type and Y type floss has not been well reported. In this study, the plaque removal effect of C type and Y type floss compared to thread type floss was experimentally verified. Methods: Thread type, C type and Y type floss were used to remove dental plaque. Ten people in each flossing group participated, and by applying dental floss to the 6 incisors of the maxilla and mandible, the degree of dental plaque was analyzed by QLF-D. To evaluate the removal degree of dental plaque before and after flossing, Simple Plaque Score (SPS), Area R30, Area R70, and Area R120 score were measured. Results: In the analysis using the Area R30 fluorescence score of the QLF-D system, the degree of plaque removal according to the application of dental floss was effective in all the thread type (p=0.018), C-type (p=0.012), and Y-type (p=0.012) floss groups compared to before the application of the floss. Among them, C type floss was more effective in removing plaque than thread type and Y type floss. However, the plaque removal effect between the three floss types was not significantly different in ∆SPS (p=0.674), ∆Area R30 (p=0.726), ∆Area R70 (p=0.504), and ∆Area R120 scores (p=0.423). Conclusion: Thread type, C type, and Y type floss were all effective in removing dental plaque, but there was no significant difference in dental plaque removal effect according to the type of floss.

• Korean Journal of Geomatics
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• v.2 no.1
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• pp.37-46
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• 2002

Accurate classification of water area is an preliminary step to accurately analyze the flooded area and damages caused by flood. This step is especially useful for monitoring the region where annually repeating flood is a problem. The accurate estimation of flooded area can ultimately be utilized as a primary source of information for the policy decision. Although SAR (Synthetic Aperture Radar) imagery with its own energy source is sensitive to the water area, its shadow effect similar to the reflectance signature of the water area should be carefully checked before accurate classification. Especially when we want to identify small flood area with mountainous environment, the step for removing shadow effect turns out to be essential in order to accurately classify the water area from the SAR imagery. In this paper, the flood area was classified and monitored using multi-temporal RADARSAT SAR images of Ok-Chun and Bo-Eun located in Chung-Book Province taken in 12th (during the flood) and 19th (after the flood) of August, 1998. We applied several steps of geometric and radiometric calculations to the SAR imagery. First we reduced the speckle noise of two SAR images and then calculated the radar backscattering coefficient $(\sigma^0)$. After that we performed the ortho-rectification via satellite orbit modeling developed in this study using the ephemeris information of the satellite images and ground control points. We also corrected radiometric distortion caused by the terrain relief. Finally, the water area was identified from two images and the flood area is calculated accordingly. The identified flood area is analyzed by overlapping with the existing land use map.

• Journal of the Korean Society of Costume
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• v.58 no.6
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• pp.54-68
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• 2008

The purpose of this study is to investigate the effect of dot pattern size(0.8, 1.8, 2.5, 5, 8), color combination(BG/R, Y/B), area-ratio on image formation. Sets of stimulus and response scales(7 point semantic) were used as experimental materials. The stimuli were 20 color pictures manipulated with the combination of dot pattern size, color combination, and area-ratio using computer simulation. The subjects were 240 female undergraduates living in Gyeongnam-do. Image factor of the stimulus was composed of 5 different components, visibility, attractiveness, cuteness, stability and high class image. In the cuteness, color combination, dot pattern size showed independent effect. In the stability, area-ratio, dot pattern size showed independent effect. Interaction effects of color and area-ratio combination was significant on cuteness. For visibility image 8cm yellow dot/blue background, for attractiveness image BG/R coloration, for cuteness image Y/B coloration and for stability image 0.8cm yellow dot/blue background were effective. According to the variation of dot pattern size, color combination and area-ratio, it was investigated that the images for a dress wearer were expressed diversely, were shown differently in image dimensions, and could be produced to different images.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.107-117
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• 2012

We estimated the potential area roof greening in Gyeonggi-do that will mitigate the heat island effect. The estimation was based on building age, roof shape, and building use which were recorded in the building register from "Sewoomteo, the Building Administration System in the Ministry of Land, Transport and Maritime Affairs. The estimated potential roof greening area in Gyeonggi-do was approximately $102.5km^2$ assuming that the buildings for residence, public, education(school), office, shopping mall are appropriate for roof greening. The area occupied by apartment buildings over six-story was 76.3% of the potential roof greening area 10.2% for individual houses, 5.9% for under five-story apartment buildings, and 3.7% for school buildings. The result indicated that it is residential buildings that we need to pay attention for roof greening, especially high-rise buildings over six-story. Greening of the whole estimated area, $102.5km^2$, in Gyeonggi-do will result in the increase of green space per capita by $8.74m^2$. This is 1.65 times greater than the area of current urban parks, and 1.97 times greater than the total area of neighborhood parks, children's parks, and pocket parks. Greening of the estimated roof area will increase green coverage of urban area by twice, adding to current green coverage of the urban areas, 11.3%, in 10 major cities. In particular, the effect of roof greening would be remarkable in inceasing the green space of Anyang City, Gwangmyeong City, and Guri City where neighborhood park area falls short.

• Environmental Analysis Health and Toxicology
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• v.20 no.4 s.51
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• pp.365-374
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• 2005

Ambient air particulate matters are classified into two distinct modes in sire distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effect on human populations has long been recognized. However, the toxicology of these adverse efforts has not been clarified. We investigated the genotoxic effect of PM 2.5 collected from urban area in Seoul by comet assay (A549 cells), CBMN assay (CHO-K1 cells) and EROD-microbioassay (H4IIE cells). Results from in vitro micronucleus assay and comet assay showed that PM 2.5 samples collected from traffic area, residential area and indoor air induced chromosomal damage and DNA breakage in a non-cytotoxic dose. The complex mixture effect of these PM 2.5 extracts was quantified by EROD-microbioassay in terms of its bio-TEQ (biologiral -TCDD equivalent concentration) which was 70.87$\pm$28.07, 93.55$\pm$21.80 and 14.31 $\pm$ 1.10 ng/g-PM 2.5 in traffic area, residental area and indoor air samples, respectively. Conclusively, we suggested that PM 2.5 collected from traffic area and residential area contains CYPIA inducer and genotoxic materials.

• Journal of Plant Biology
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• v.12 no.2
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• pp.28-42
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• 1969

Field studies were conducted with the split plot design of 20 treatment with a combination of 4 levels of 3, 5, 7 and 9 plants per hill and 5 levels of 60, 80, 100, 120 and 140 hills per 3.3$m^2$ on non-, low- and high-salty areas. Rice variety, Kusabue was grown under jthe standard fertilization and cultivating. Investigation was made on the productive structure of plant population, leaf-area index, light intensity curve by stratum of crop population at the panicle differentiation stage. The competition density effect on the photosynthetic capacity was low as the salt concentration became higher. This seemed to suggest the possiblity of an increased yielding capacity by closer planting in the salty areas. The effect of an increased number of hills per unit area was greater than that of an increased unmber of plants per hill due to the total leaf area and space distribution of the actie assimilation parts of rice plants. The number of ppanicle per unit area in the salty areas were increased when the number of hill per 3.3$m^2$ increased over an increased number of plants per hill, and the panicle weight was reduced by close planting in the non-lalty area, while it was not reduced so much in the salty areas. The number of grains per panicle was significantly decreased by close planting in the salty areas as in the non-salty area, and ratio of matured grain was not decreased even by close planting in the salty areas, while it was significantly decreased by close planting in the non-salty area. An increase in the rice yield was possible by close planting and greatly related to leaf area index in the salty areas but not in the non-salty area. Increasing the number of hills per unit area showed greater effect on the increase of the rice yield than an increased number of plants per hill in the salty areas. Relationships between the growth characteristics and the rice population affected by plant spacing mode for maximum production were discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.622-629
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• 2011

We investigated the effect of the discharged water from Bong Stream, which is located in the drainage area of Gangjinman area on the bacteriological water quality in the coastal area after rainfall events. Following 12.5 mm of rainfall, water discharged from Bong Stream had a very limited effect on bacteriological water quality in adjacent area and the affected area did not extend to the designated area. On the other hand, after 23 mm rainfall, the density of fecal coliform at stations located in the designated area was higher than at stations located in the adjacent area. The degree of bacteriological contamination at the surveyed stations in the coastal area after rainfall events did not show a relationship with distance from the shoreline. These results indicate that the direction of spread and the range of contaminants from the drainage area were affected by tides at the time of the survey. Therefore, a detailed survey of the effects of tides on the diffusion characteristics of the contaminants from Bong Stream is needed to establish a proper management plan for the surveyed area.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.65-73
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• 2007

The use of an Exhaust Gas Recirculation(EGR) for a diesel engine with variable geometry turbocharger(VGT) has confronted how to obtain the amount of EGR for NOx reduction requirement at wide operating range and less side effect. Through a combined effort of modeling(wave action simulation) and experiment, an investigation into the effect of EGR area ratio and pipe length on EGR characteristics of common rail diesel engine with VGT has been performed. For accurate computation, calibration of constants involved in empirical and semi-empirical correlations has been performed at a specific operating point, before of its use for engine simulation. From the results of this study, it was found that EGR rate is sharply increased with increasing EGR area ratio until area ratio of 0.3. However, the effect of EGR area ratio on EGR rate is negligible beyond this criteria. This study also investigates the effect of EGR pipe length on a EGR amount and pulsating flow characteristics at EGR junction. The results showed that the longer EGR pipe length, the lower EGR amount was achieved due to the flow loss resulting in lower amplitude of pressure wave.