• Korean Journal of Health Education and Promotion
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• v.8 no.2
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• pp.74-86
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• 1991

This study tried to clear the characteristics of height growth pattern depending on Peak Height Velocity age in early, average and late groups. And in it, height growth tendency of girl students in age 7 to 18 years old was compared and investigated in order to know influencing factors, menarcheal age relation. The samples were senior girl students at high school in Seoul. Longitudinal data and survey data were collected in August, 1990. The results could be summarized as follows: 1. On distance curve, the height growth line in early group tended to be the highest and in late group the lowest. On the other hand, on velocity curve late group showed the highest peak and early group showed the lowest peak. In late group, velocity curve was too steep. Of course, these early, average and late groups were classified by PHV age. 2. In these three groups, late group showed the most growth amount per year. However, on distance curve, early group showed higher line than late group. Perhaps this means that peak growth amount in late group might have an effect on mean. 3. Growth amount of adolescence spurt age in these three groups was 6.86cm at age 9(early group), 7.27cm at l1(average group) and 7.65cm at 13(late group). In early group, because. PHV age came too early, it was difficult to find exact adolescence spurt period. In early group, the adolescence spurt period is considered to come at about age 7 to 9. In average group, at 9 to 11 and at 12 to 13 in late group. Especially, spurt of late group was remarkable. 4. When the growth amount of PA, before PA and after PA was compared, growth amount of PA in all three groups was about 20%. In early group, growth amount of APV tended to be large and in late group, that of APV tended to be large and in late group, that of BPV was large. In average group, growth amount of BPV was larger than that of APV. 5. For the purpose of comparing total height growth amount of these groups at age 18, the height growth was assumed to be over. And then, the difference of three groups was studied but it's not significant. 6. Although the difference between height growth and family environment, dietary habits, exercise, disease history in these three groups was investigated, only the income was significant. The significance of all the other factors was not approved. 7. When menarcheal age was compared with PA, generally we know menarche appeared after 1∼2 years of PHV age. But in case of early group, the difference between PHV age and menarcheal age was 5.34 years. In average group, 2.45 years and 0.82 years in late group.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.90-97
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• 2022

This study was carried out to investigate the effect of side vent heights on temperature and relative humidity inside and outside the single-span plastic greenhouse (W: 7 m, L: 40 m H: 3.9 m) during natural ventilation. Four different heights (120, 100, 80, 60 cm) of the side vent were used as an experimental condition. Variations of temperature and relative humidity inside and outside the greenhouse and the differences between heights were compared by using one-way ANOVA. In the daytime, the difference in temperature between inside and outside the greenhouse was dropped from 14.0℃ to 7.1℃ as the side vent height increased. The temperature difference in the nighttime was less than 0.2℃ regardless of the height. One-way ANOVA on the temperature difference between heights presented that the statistical significance was founded between all of the combinations of height in the daytime. The difference in relative humidity between inside and outside the greenhouse was grown from -13.8% to -22.2% with a decrease in the side vent height. The humidity difference in the nighttime was less than 1% regardless of the height. One-way ANOVA on the humidity difference revealed that most of the side vent heights showed significance in the daytime but between 100 and 80 cm was not significant. It seemed because the external air became cooler during the experiment with a height of 80 cm. Conclusively, this study empirically demonstrated that the higher side vents resulted in the decrease of differences in temperature and relative humidity between inside and outside the greenhouse, and also the effect of side vent height was statistically significant. This study may be helpful for deciding the height of the side vent effective for controlling temperature and relative humidity in a single-span greenhouse during natural ventilation.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.31-34
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• 2002

In this study, thermal analysis of a thermal capacitor, which is used to cool the current lead in conduction-cooled superconducting systems, was done. The temperature difference across a thermal capacitor was calculated by using heat conduction equation. Effect of heat load, total thickness, height and length of a thermal capacitor on the temperature difference were show. Using the results in this work, total thickness and heat height of a thermal capacitor can be determined for given heat load and given temperature difference. This work can be used practically in design for every superconduction system using a current lead.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.205-208
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• 2002

This study is performed to examine the flowability and filling ability of steel fiber reinforced high performance concrete. For the estimation of the flowability and filling ability, slump flow, box height difference and L-shape filling appearence are measured and compared. The test result shows that the slump flow is $60{\pm}5cm$ to make no difference with containing steel fiber, box height difference is increased with increasing steel fiber and L-shape filling appearence is to bad with increasing steel fiber. But, proper containg of steel fiber is considered to be applied for high performance concrete without decreasing of slump flow and filling ability.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.519-528
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• 2020

Purpose of this study is to analyze the changes in state anxiety, heart rate, and fall efficacy of the elderly through the handle height of walking assistant vehicle (WAV). The subjects were 32 elderlies. WAV was in the form of strollers, and it's handle height was set as 48% of a subject's total height. Also, it's height was divided into 48, 43, 38%. To measure the state anxiety, Korean State-Trait Anxiety Inventory was used and to measure the heart rate, Fitbit Charge 2 wrist heart rate monitor was used. To measure the fall efficacy, Fall Efficacy Scale-Korea was used. As the results of state anxiety and heart rate, the statistically significant increase showed continuously through the decrease of the handle height of WAV. As the results of fall efficacy, the statistically significant decrease showed continuously through the decrease of the handle height of WAV. In all of the post hoc test, the results of the state anxiety and fall efficacy showed significant difference among the each handle height of WAV and the results of the heart rate showed significant difference between the 48, 43% and 38% handle height of WAV. Thus, to decrease the state anxiety and heart rate and increase the fall efficacy of the elderly, the handle height of WAV should be properly positioned and considered to adjust to 48% of the user's total height.

• Journal of Environmental Science International
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• v.21 no.9
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• pp.1097-1113
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• 2012

Ozone is the secondary photochemical pollutant formed from ozone precursor such as nitrogen dioxide and non-methane volatile organic compounds(VOCs). The ambient concentration of ozone depends on several factors: sunshine intensity, atmospheric convection, the height of the thermal inversion layer, concentrations of nitrogen oxides and VOCs. Busan is located in the southeast coastal area of Korea so the ozone concentration of Busan is mainly affected from the meteorological variables related to the sea such as sea breeze. In this study the ozone concentrations of Busan in 2008~2010 were used to analyse the cause of the regional ozone difference in eastern area of Busan. The average ozone concentration of Youngsuri was highest in Busan however the average ozone concentration of Gijang was equal to the average ozone concentration of Busan in 2008~2010. The two sites are located in eastern area of Busan but the distance of two sites is only 9km. To find the reason for the difference of ozone concentration between Youngsuri and Gijang, the meteorological variables in two sites were analyzed. For the analysis of meteorological variables the atmospheric numerical model WRF(Weather Research and Forecasting) was used at the day of the maximum and minimum difference in the ozone concentration at the two sites. As a result of analysis, when the boundary layer height was lower and the sea breeze was weaker in Youngsuri, the ozone concentration of Youngsuri was high. Furthermore when the sea breeze blew from the south in the eastern area of Busan, the sea breeze at Youngsuri turned into the southeast and the intensity of sea breeze was weaker because of the mountain in the southern region of Youngsuri. In that case, the difference of ozone concentration between Youngsuri and Gijang was considerable.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.2
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• pp.167-173
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• 1998

Many workers like welders work in squatting postures with the object on the ground during an entire work shift. It is suspected that such prolonged squatting without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is to examine the physical stress caused by the prolonged squatting and to recommend a safe work/rest schedule for a welding task with squatting posture based on the lab experiments. In this study, 8 healthy student subjects participated in the experiment. They maintained a squatting work posture for 16 minutes with 4 different stool height conditions: no stool; 10cm height; 15cm height; and 20cm height. Every 2 minutes, the discomfort was subjectively assessed with the magnitude estimation method for the whole body, lower back, upper leg and lower leg. Based on discomfort ratings, we found that a 10cm height stool relieved the workload most. Discomfort rating results also indicated that a 20cm height stool showed the highest workload, and the there were no difference in workload between a 15cm height stool and no stool. We recommend to use low height stools and to maintain such working postures no longer than 6 minutes for prolonged squatting tasks.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.295-306
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• 1994

The object of this experiment was to suggest the suitable cutting frequency and cutting height for orchardgrass (0G)-red clover(RC) mixtures under the intensive system of short-term pasture utilization. The fields trials were conducted over 3-year period(1991-1993) to evaluate dry matter yield, botanical composition, chemical composition and CP, DDM yield on the cutting frequency (30, 40 and 50 days) and cutting height(5, 7 and 9cm) With decreasing the cutting frequency, the DM yield of OG in the OG-RC mixtures was significantly increased(P

• Journal of Digital Contents Society
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• v.7 no.1
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• pp.9-14
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• 2006

In this paper, we propose the algorithm that automatically measures the height of the object to move on the base plane by using the geometric information. To extract a moving object from images, we use the difference image and morphology operation. The top and bottom point of an object are extracted by the histogram vertical projection in the extracted region. The two points, top and bottom, are used for measuring the height. Given the vanishing line of the ground plane, the vertical vanishing point, and at least one reference height in the scene; then the height of any point from the ground may be computed by specifying the image of the point and the image of the vertical intersection with the ground plane at that point. Through a confidence valuation of the height to be measured, we confirmed similar actual height and result in the simulation experiment.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.1 s.29
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• pp.49-58
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• 1989

A clothing-erogonomics study was performed to investigate the difference of the upper arm skin skin surface and the relationship among the three aspects of upper arm (height of sleeve rap, sleeve width and armhole girth) by changing arm movements. Plaster cast was used for this experimental research. Arm movements consist of 9 types; just carmly standing on ($0^{\circ}$), and each 4 types ($45^{\circ},\;90^{\circ},\;135^{\circ},\;180^{\circ}$) to the vertical direction in front and in side. The results were as follows; 1) As the arm-movement angle increased, the height of sleeve cap decreased and that ratio was largest in the portion A-B3. 2) The steeve width was enlarged with the increment of movement angle in all portions of upper arm except B1-B5. 3) As increasing the movement angle, the whole armhole girth decreased and the ratio o(front armhole girth (F-A) was larger than that of back. 4) In the vertical direction in front, the height o( the sleeve caps was larger, the sleeve widths were smaller than in the vertical direction in side in all movement types, but there was no significant difference in arm-hole girth between the two cases. 5) There were significantly negative relationships between measurements in height of sleeve cap and those in sleeve width, and also between those in height of sleeve cap and in arm-hole girth. And significantly positive relationships were found between neasurements in height of sleeve cap and those in arm-hole girth.