• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.7
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• pp.591-598
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• 2015

Pool boiling heat transfer coefficients of a LiBr solution were obtained for seven low fin tubes having different fin pitch and fin height. The test range covered saturation pressure from 7.38kPa to 101.3kPa, heat flux from $20kW/m^2$ to $40 kW/m^2$ and LiBr concentration from 0% to 50%. The optimum fin geometry for the present experimental range turned out to be 26 fpi with 0.18 mm fin height.The advantage of added heat transfer area and the disadvantage of slower bubble growth and departure appear to have yielded an optimum fin pitch. The heat transfer coefficient decreased as saturation pressure decreased and Libr concentration increased. The reason may be attributed to the low saturation pressure, which increased the bubble departure diameter and decreased the bubble departure frequency. As the LiBr concenreation increased, the saturation temperature increased and the mass diffusion rate decreased, which resulted in a reduced heat transfer coefficient. The heat transfer coefficients of the low fin tube were greater than those of the smooth tube. Correlations were developed based on the present data.

• Journal of Korean Society of Forest Science
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• v.95 no.5
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• pp.614-620
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• 2006

To study the chlorophyll contents and photosynthetic characteristics of 4 tree species of deciduous hardwoods; Betula platyphylla var. japonica, Zelkova serrata, Acer mono and Prunus sargentii were treated in 3 stages of shading; the full sun treatment, the medium shade treatment with 30% of transmittance comparing to full sun, the intense shade treatment with 8% of transmittance and their changes in chlorophyll contents and photosynthetic characteristics were examined and analyzed. Most hardwoods showed differences in the total chlorophyll contents in the order of May < September < July, however, that in Prunus sargentii increased progressively along with the lapse of time. Concerning the degree of shading, total chlorophyll contents increased in proportion to the level of shading. Betula platyphylla var. japonica and Prunus sargentii showed more than 2-3 times difference between the full sun treatment and the intense shade treatment. The changes in photosynthetic characteristics, the range of the light saturation point of the trees was $1,000{\sim}1,100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in May, before the shading was applied, and the intensity was shown in the order of Betula platyphylla var. japonica > Zelkova serrata > Acer mono > Prunus sargentii. The photosynthetic rate was $6.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}{\sim}27.1{\mu}mol{\cdot}CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of Betula platyphylla var. japonica > Prunus sargentii > Acer mono > Zelkova serrata that there were differences between species. Concerning the changes in light saturation point in each growth period after shading treatment, the light saturation point in the full sun treatment was found in the range of $560{\sim}1,100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and the level of intensity was shown in the order of May > July > September. The light saturation point decreased as the level of shading intensified and the level of changes in light compensation point in the full sun treatment for Betula platyphylla var. japonica and Prunus sargentii was shown in the range of $2.9{\sim}27.1{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of May > July > September, however, for Zelkova serrata and Acer mono was shown in the range of $3.9{\sim}11.7{\mu}mol{\cdot}CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of July > May > September that there were differences between species.

• Journal of Korea Water Resources Association
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• v.54 no.12
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• pp.1205-1214
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• 2021

Precipitation is one of a major causes of landslides by rising of pore water pressure, which leads to fluctuations of soil strength and stress. For this reason, precipitation is the most frequently used to determine the landslide thresholds. However, using only precipitation has limitations in predicting and estimating slope stability quantitatively for reducing false alarm events. On the other hand, Soil Moisture (SM) has been used for calculating slope stability in many studies since it is directly related to pore water pressure than precipitation. Therefore, this study attempted to evaluate the appropriateness of applying soil moisture in determining the landslide threshold. First, the reactivity of soil saturation level to precipitation was identified through time-series analysis. The precipitation threshold was calculated using daily precipitation (P_daily) and the Antecedent Precipitation Index (API), and the hydrological threshold was calculated using daily precipitation and soil saturation level. Using a contingency table, these two thresholds were assessed qualitatively. In results, compared to P_daily only threshold, Goesan showed an improvement of 75% (P_daily + API) and 42% (P_daily + SM) and Changsu showed an improvement of 33% (P_daily + API) and 44% (P_daily + SM), respectively. Both API and SM effectively enhanced the Critical Success Index (CSI) and reduced the False Alarm Rate (FAR). In the future, studies such as calculating rainfall intensity required to cause/trigger landslides through soil saturation level or estimating rainfall resistance according to the soil saturation level are expected to contribute to improving landslide prediction accuracy.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.203-215
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• 2016

This study was performed in order to investigate the effect of breast milk on pain relief in newborn during heel lancing. Nonequivalent control group pretest-posttest design by double blinded experiment was used. 50 neonates were randomized to receive breast milk (experimental group, n=25) or no treatment (control group, n=25) before undergoing heel lancing. Informed consent was obtained from parents of 50 neonates. Neonatal infant pain scale (NIPS), respiration rate, heart rate, oxygen saturation, and crying duration were used to assess subjects' pain reaction. Data were analyzed using SPSS 18.0. The experimental and control group showed a statistically significant differences in NIPS score (F=28.89, p<.001), heart rate (F=14.03, p<.001), respiration rate (F=4.79, p=.001), oxygen saturation (F=2.69, p=.027), and crying duration (t=-8.78, p <.001) at each time points (during heel lancing, right after heel lancing, 1, 2, 3 minutes after heel lancing). The result suggest that oral administration of expressed breast milk is safe and natural agents for reducing procedural pain of neonates. Another clinical trial study with more samples is recommended.

• Korean Journal of Acupuncture
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• v.27 no.2
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• pp.203-216
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• 2010

Objectives : The purpose of this study is to identify the effect of tonifying or sedative manipulation on LI4 and KI7 for sweet deficiency under cold environment. Methods : The participants were divided into 4 groups; intact group without acupuncture(Intact), acupuncture group inserting straightly with LI4 & KI7 method((LI4-straight KI7-straight), acupuncture group inserting twisting with LI4 tonificaton & KI7 tonificaton method(LI4-tonify KI7-tonify) and acupuncture group inserting twisting with LI4 sedation & KI7 sedation method(LI4-purge KI7-purge). We obtained the baseline data under cold condition with the temperature $14{\pm}1^{\circ}C$. After making the participant staying under cold condition for 10 minute, we measured sweating rate on skin surface and biological responses such as body temperature, oxygen saturation, pulse rate, systolic blood pressure, diastolic blood pressure, deoxy-Hb and oxy-Hb in subcutaneous. Results : The sweating rate on skin surface was not different in all treatment groups compared to the intact group. The body temperature was significantly increased in LI4-straight KI7-straight group compared to the intact group. The oxygen saturation significantly increased in LI4-purge KI7-purge group compared to the intact group. The systolic blood pressure was significantly increased in LI4-purge KI7-purge group compared to the intact group. The deoxy-Hb was significantly decreased in LI4-purge KI7-purge group compared to the intact group. Conclusions : The above results, the effect of LI4, KI7 acupuncture due to the tonifying or sedative manipulation on sweating control could be observed. However, other biological responses with the acupuncture of tonifying or sedative manipulation were giving different expressions. We suggest that continued research of tonifying or sedative manipulation is of importance order to find these expressions.

• Journal of Ginseng Research
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• v.26 no.2
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• pp.85-88
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• 2002

This study was carried out to obtain information of the photosynthetic rate at various temperature and light intensity, stomata, chlorophyll, specific leaf weight, characteristics of aerial part and root in ginseng new cultivars developed by pure line selection. The light saturation point of leaves in new cultivars and Jakyungjong were 15,000 lux, and the optimum air temperature on the photosynthesis of new cultivars and Jakyungjong were 20$\^{C}$. The photosynthetic rates were increased in order of Jakyungjong, Gopoong, Chunpoong and Yunpoong. The dark respiration rate of leaves in ginseng cultivars were increased according to the increasing of temperature, and the dark respiration rate of leaves of Yunpoong was the highest among cultivars. The specific leaf weight (SLW) were increased in order of Jakyungjong, Yunpoong, Gopoong, Chunpoong, but total chlorophyll contents were not different among cultivars. Stomata frequency of Yunpoong was the highest being 69.2ea among cultivars, while the length of stomata was reverse. Yunpoong was superior in aerial part among ginseng cultivars : the number of stem was 1.8ea, the number of palmately leaves was 7.7ea, the number of leaflets was 41.0ea, leaf area was 12.3 dm$^2$ The root weight were increased in order of Jakyungjong, Gopoong, Chunpoong and Yunpoong. Chunpoong and Gopoong hove good root shape the length of tap root in Chunpoong and Gopoong were the longest being 6.5 cm and 6.8 cm respectively, but that in Yunpoong was the shortest being 4.4 cm.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.22 no.1
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• pp.29-62
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• 2018

We investigate a class of HIV infection models with two kinds of target cells: $CD4^+$ T cells and macrophages. We incorporate three distributed time delays into the models. Moreover, we consider the effect of humoral immunity on the dynamical behavior of the HIV. The viruses are produced from four types of infected cells: short-lived infected $CD4^+$T cells, long-lived chronically infected $CD4^+$T cells, short-lived infected macrophages and long-lived chronically infected macrophages. The drug efficacy is assumed to be different for the two types of target cells. The HIV-target incidence rate is given by bilinear and saturation functional response while, for the third model, both HIV-target incidence rate and neutralization rate of viruses are given by nonlinear general functions. We show that the solutions of the proposed models are nonnegative and ultimately bounded. We derive two threshold parameters which fully determine the positivity and stability of the three steady states of the models. Using Lyapunov functionals, we established the global stability of the steady states of the models. The theoretical results are confirmed by numerical simulations.

• Journal of radiological science and technology
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• v.11 no.1
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• pp.33-41
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• 1988

This study was measured the radiation-induced current - X-ray dose, dose rate, X-ray quality, time, temperature, electric field characteristics and the dependence of gap length in insulating oil under of D.C. Voltage before, during and after X-ray irradiation. The obtained results can be summarized as following. 1. The radiation - induced current is more the dependence of X-ray quality (tube voltage) than quantity (tube current), the dependence of quantity is appeared at the high than low X-.ay tube voltage. 2. The dependence of dose rate is appeared at the more dose rate, and ${\triangle}\;=\;0.64{\sim}0.74$. 3. The higher temperature of insulating oil and X-ray tube voltage (X-ray quality) is increased, at the low electric field, the more radiation-induced current. 4. $G_{eq}-G_{o}(={\triangle}G)$ is increased at the low than high temperature, high than low X-ray quality. 5. The dependence of temperature is appeared before than during X-ray irradiation. 6. The RIC saturation region is appeared at the high than low insulating oil temperature during (1000 V/cm above) than before (4000 V/cm above) X-ray irradiation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.214-222
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• 1998

These experiments were conducted to investigate water uptake, electrical conductivity, germination percentage, seedling growth, and seedling establishment rate in direct seeding cultivation of rice. The rice seeds of six japonica type varieties were coated with 12 kinds of polymers in a standard concentration of 0.2% using seed coating machine. The water absorption of the polymer-coated seeds under saturation conditions was not different among varieties, and was the highest in kulcel, maltrin, and waterlock on the polymer-coated seeds. The electrical conductivity with waterlock (55.0 $\mu scm^{-1}g^{-1}$) was higher than the control plot (45.6 $\mu scm^{-1}g^{-1}$) and other treatments. The germination of the polymer-coated seeds was 95.9% at control plot, 92.7% at low temperature and 35.7% at high temperature. The total dry weight of seed decreased in the order of low temperature, control plot, and high temperature, and was effective in pvp (polyvinyl pyrrolidone), opadry, and sacrust. The seedling establishment rate in direct seeding cultivation ranged from 74.9 to 81.0% in flooded paddy surface, and ranged from 64.7 to 76.6% in dry paddy. In both cases, it decreased in the order of early, medium and medium-late varieties, but was enhanced in daran 8600, sepirect, and sacrust. According to this study the recommended polymers for direct seeding cultivation of rice are daran 8600, sepirect, and sacrust.

• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.342-347
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• 1993

It was proved that the cell growth followed a photo-inhibition model in light-limited turbidostat cultivation, having 1.06 (1/h) of maximum specific growth rate and 0.00094(kcal/$cm^2$/h) and 0.063 (kcal/$cm^2$/h) as half saturation and light inhibition constants, repectively. ${\beta}$-carotene production showed a growth related porcess. And the activation energy of Dunaliella salina was roughly estimated as 12.36 (kcal/mole) in employing Arrhenius relationship. It should also point out that relatively much porduction of ${\beta}$-carotene was observed at hight light intensity with yieding 1.04 (mg-carotene/g-dry cell/day) of specific product production rate while the cell growth was decreased. The optimal conditions of producing ${\beta}$-carotene in turbiodostat cultivation were as follows: $7.5{\times}10^{-3}$(kcal/$cm^2$/h)of light intensity, 2 (mM) and 50(mM) of nitrate and sodium bicarbonate concentrations and 100(ml/h) of $CO_2$ flow rate.