• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.29-39
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• 1999

An earlier study of the effect of rain found that the capacity of freeway systems was reduced, but did not address the effects of rain on the nature of traffic flows. Indeed, the substantial variation due to the intensity of adverse weather conditions is entirely rational so that its effects must be considered in freeway facility design. However, all of the data in Highway Capacity Manual(HCM) have come from ideal conditions. The primary objective of this study is to investigate the effect of rain on urban freeway traffic flows in Seoul. To do so, the relations between three key traffic variables(flow rates, speed, occupancy), their threshold values between congested and uncontested traffic flow regimes, and speed distribution were investigated. The traffic data from Olympic Expressway in Seoul were obtained from Imagine Detection System (Autoscope) with 30 seconds and 1 minute time periods. The slope of the regression line relating flow to occupancy in the uncongested regime decreases when it is raining. In essence, this result indicates that the average service flow rate (it may be interpreted as a capacity of freeway) is reduced as weather conditions deteriorate. The reduction is in the range between 10 and 20%, which agrees with the range proposed by 1994 US HCM. It is noteworthy that the service flow rates of inner lanes are relatively higher than those of other lanes. The average speed is also reduced in rainy day, but the flow-speed relationship and the threshold values of speed and occupancy (these are called critical speed and critical occupancy) are not very sensitive to the weather conditions.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.93-100
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• 2011

Maintenance of adequate soil water potential during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement within and below the rooting zone can facilitate optimal irrigation scheduling aimed at minimizing the adverse effects of water stress on crop growth and development and the leaching of water below the root zone which can have adverse environmental effects. The objective of this study was to evaluate the feasibility of using a portable irrigation controller with an Watermark sensor for the cultivation of drip-irrigated vegetable crops in a greenhouse. The control capability of the irrigation controller for a soil water potential of -20 kPa was evaluated under summer conditions by cultivating 45-day-old tomato plants grown in three differently textured soils (sandy loam, loam, and loamy sands). Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30 cm depths. Even though a repeatable cycling of soil water potential occurred for the potential treatment, the lower limit of the Watermark (about 0 kPa) obtained in this study presented a limitation of using the Watermark sensor for optimal irrigation of tomato plants where -20 kPa was used as a point for triggering irrigations. This problem might be related to the slow response time and inadequate soil-sensor interface of the Watermark sensor as compared to a porous and ceramic cup-based tensiometer with a sensitive pressure transducer. In addition, the irrigation time of 50 to 60 min at each of the irrigation operation gave a rapid drop of the potential to zero, resulting in over irrigation of tomatoes. There were differences in water content among the three different soil types under the variable rate irrigation, showing a range of water contents of 16 to 24%, 17 to 28%, and 24 to 32% for loamy sand, sandy loam, and loam soils, respectively. The greatest rate increase in water content was observed in the top of 10 cm depth of sandy loam soil within almost 60 min from the start of irrigation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.1
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• pp.63-71
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• 2015

Moisturizers are the most prescribed products in dermatology. Treatment with moisturizers aims to maintain skin integrity and overall well-being by providing a healthy appearance. Moisturizers perform very important functions in baby care; however, there are few studies on the effects of moisturizers on the skin of infants. To investigate the effects of moisturizers on the skin of healthy full-term infants and toddlers, thirty-one healthy, full-term, 6- to 36-month-old infants and toddlers without any dermatologic conditions received moisturizer applied to the whole body except the eyes and diaper area after bathing twice daily for 4 weeks. Clinical assessments were conducted before treatment, immediately after the treatment period, and 1 and 4 weeks after treatment. At all visits, skin hydration, transepidermal water loss (TEWL), skin pH, and skin roughness were measured, the skin surface was photographed, and any adverse events were recorded. After using moisturizer, skin hydration significantly increased and TEWL and roughness significantly decreased. The skin pH was modified to mildly acidic and the skin surface was visually smoother than before treatment. There were no statistical significant differences of effects of moisturizers according to age and sex, and adverse events were not observed. The results of moisturizer application on the skin were increased skin hydration, recovery of barrier function, balancing skin pH within a mildly acidic range, and increasing the smoothness of the skin surface for 4 weeks.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2177-2190
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• 1971

This experiment was made to determienthe effect of various soil moisture contents in simulated drought conditions on different stages of rice growth. The drought conditions were developed at such three rice-growing stages as transplanting, immediately after transplanting and young ear forming. Three different lengths of drought periods, which are ten days, twenty days and thirty days, were applied for each growing stage of rice. The rice variety used this experiment is Nong-rim 29. This experiment was conducted at the university farm of the Kon-Kuk University during the period of $1968{\sim}1970$. Three reprications for each of 12 treatments and split plot design were employed in this study. Bottomless wood square boxes, $1^m{\times}1^m{\times}1^m$, were burried in the test plot and box top was covered with poloyethylene sheets to avoid natural rainfall drops. Standard plots were irrigated continuously with a water depth of 40mm/day and those of drought treatments were irrigated continuously up to the beginning of the planned drought period, and they were irrigated again with a depth of 40mm/day up to the maturing stage of rice. Other methods for rice raising followed those methods developed by the Field Crops Experiment Station of the Office of Rural Development. During this experiments, climatic conditions in regard to rainfalls, sunshine hours, and temperatures were observed. According to this observation, those values measured deviate slightly from the annual means. However the growing condition of rice plants were normal. The pH value of irritation water is nearly neutral, and soils in the test plots are relatively fertile, being similar to ordinary paddy soils. Analysis of variances for number of stalks, plan-height, ear sprouting date, length of stalks, ear length, number of ears per plant, fertility, grain weitght, weight of plant, and yield were carried out. The variances for plant height, ear sprouting date, length of stalk ear length, and yield has statistical significance under drought treatments applied at three different growing stages. The variance showing the effect of lengths of drought period is highly significant for all the treatments studied except that of grain weight. The interaction between drought periods and drought treatments at different growing stages is significant for plant height, stalk length, ear length, number of ears, fertility and yield, these results indicated that droughts at different growing stages have influence on plant height, ear length, yield, and length of drought period also has strong influence on all factors studied except grain weight. The combination of drought treatments at different rice growing stages and lengths of drought periods has different effects on various agronomic characteristics, including yield. Plant height under drought treatment practiced at transplanting stage is the lowest, and drought treatment applied immediately after transplanting resulted in the least number of stalks. The effect of different lengths of drought periods on plant height and number of stalks depends signis ficantly on increasing days of drought. Ear sprouting date tends to be delayed for one or two days undedrought treatments at transplanting period and with increasing days of drought. Better yield is secured in drought treatment applied immediately after transplanting. Adverse effect war observed when drought treatment was applied at ear forming period. These effects may be attributed to the alternation of irrigation and drought causing vigorous root activity. In general, yield linearly decreases as the length of the drought period increases. The results obtained in this study demonstrate that, in order to mimimize damage due to drought, and, to save irrigation water, paddy fields, immediately after transplanting, may be not irrigated, since there is sufficient moisture in the soil, and that sufficient irrigation water should be applied again in the ear forming stage of rice plant.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.286-294
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• 2014

The purpose of this study is to investigate the effects of applying density current generator (hereafter referred to as DCG to large lakes on the operating conditions of DCG, de-stratification, water quality improvement and inhibition of algae occurrence. As a result of a survey conducted to derive the optimum operating parameters of DCG in a condition to minimize eco-toxicity, the following conclusions were obtained. During the survey period, a marked stratification appeared in September to October 2011 and May 2012. At this time, the average depth of water to form thermocline was found to be $5{\pm}2$ m, so the location of discharge port for the operation of DCG was determined to be about 5 m below from the surface. To minimize the adverse effects of benthos and obtain the effect of water mixture at the time of water circulation, the mixing ratio of surface water and deep water was designed to be 3:1 by means of ecotoxicological assessment on the DCG operating characteristics. To select the appropriate operating hours for DCG, DCG was operated by 12 hr, 24 hr, 36 hr and 48 hr. As its result, the formation of thermocline did not occur during the operation of 36 hr. Also, It was effected that start reoperating from 3rd day after stop 2days under the condition of operated during 36 hr with calculated power consumption. Under the above conditions, the results of DO and water temperature analysis during the operation of DCG showed that the stratification, which was distinct previously, appeared to be weak, and relatively lower levels than those before operation were found as a result of water quality analysis on COD and chlorophyll-a, which leads to the conclusion that the water body is maintained at a stable condition due to the circulation of water by the occurrence of density current resulting from the operation of DCG.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.3
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• pp.145-154
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• 2022

Due to abnormal weather conditions caused by climate change, natural disasters and damages are gradually increasing around the world. Global climate change as accompanied by warming is projected to exert adverse impact on production of potato, which is known as cool season crop. Even though, role of potato as a food security crop is expected to increase in the future, the climate change impacts on potato and adaption strategies are not sufficiently established. Therefore, this study was conducted to analyze the damage pattern of potatoes due to high temperature treatment and to evaluate the response of cultivars. T he high temperature treatment (35~38℃) induced heat stress by sealing the plastic house in midsummer (July), and the quantity and quality characteristics of potatoes were compared with the control group. T otal yield, marketable yield (>80 g) and the number of tubers per plants decreased when heat treatment was performed, and statistical significance was evident. In the heat treatment, 'Jayoung' cultivar suffered a high heat damage with an 84% reduction in yield of >80 g compared to the control group. However, in Jopung cultivar, the decrease was relatively small at 26%. Tuber physiological disturbances (Secondary growth, Tuber cracking, Malformation) tended to increase in the heat stress. Under heat conditions, the tubers were elongated overall, which means that the marketability of potatoes was lowered. T he tuber firmness and dry matter content tended to decrease significantly in the heat-treated group. T herefore, the yield and quality of tubers were damaged when growing potatoes in heat conditions. T he cultivar with high heat adaptability was 'Jopung'. T his result can be used as basic data for potato growers and breeding of heat-resistant cultivars.

• Journal of Life Science
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• v.19 no.4
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• pp.429-435
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• 2009

Oxidative stress is a consequence of an imbalance of the defense system against cellular damage generated by reactive oxygen species (ROSs) such as superoxide anions (menadione; MD). Most organisms have evolved a variety of defense systems to protect cells from adverse conditions. In order to evaluate stress tolerance against oxidative stress generating MD, comparative analyses of antioxidant capacity, or free radical scavenger ability, were performed between S. cerevisiae KNU5377 (KNU5377) and three wild-type S. cerevisiae strains. In a medium containing 0.4 mM MD, the KNU5377 strain showed higher cell viability and antioxidant ability, and contained higher levels of trehalose, superoxide dismutase, thioredoxin system, glucose-6-phosphate dehydrogenase, and some heat shock proteins. The KNU5377 strain also produced a lower level of oxidative stress biomarker than the other three yeast strains. These results indicate that S. cerevisiae KNU5377 has a higher level of tolerance to oxidative stress due to the increased expression of cell rescue proteins and molecules, thus alleviating cellular damage more efficiently than other S. cerevisiae strains.

• Toxicological Research
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• v.18 no.1
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• pp.87-98
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• 2002

This study was conducted to evaluate the safety of a recombinant human Factor VIII(GC-$\gamma$ AHF) manufactured by Korea Green Cross Company with different technology according to the Regulation of Korean Food and Drug Administration (l 998. 12. 3). In acute toxicity test, both genders of Sprague-Dawley rats and Beagle dogs were administered intravenously with GC-$\gamma$ AHF of three doses (3,125, 625 and 125 IU/kg), and single dose of 3,125 IU/kg, respectively. No dead animal and abnormal autopsy findings were found in Control and GC-$\gamma$ AHF treated group. Therefore, the 50% lethal dose ($LD_{50}$) of GC-$\gamma$ AHF was conidered to be higher than 3,125 IU/kg in rats and dogs. In the four weeks repeated intravenous toxicity study, GC-$\gamma$ AHF was administrated intravenosly to both genders of rats and dogs with 3 doses (500, 150, 50 IU/kg). There were neither dead animals nor significant changes of body weights during the experimental Period. In addition, no significant GC-$\gamma$ AHF related changes were found in clinical sign, urinalysis and other finding. Statistically changes were observed in hematological, biochemical and organ weight parameters of treated groups: however these changes were not dose dependent. No histopathological lesion were observed in both control and treated animals. Above data suggest that no observed adverse effect level of test materials in rats and dogs might be over 500 IU/kg/day in this study. In ocular irritation test, any injury on iris, conjunctiva and cornea in rabbits were not observed. The acute ocular irritation index (A.O.I.), mean ocular irritation index (M.O.I.) and Day-7 individual ocular irritation Index (I.O.I.) of GC-$\gamma$ AHF were 0. In the primary skin Irritation test, the primary irritation index (P.I.I.) oj GC-$\gamma$ AHF were 0. Therefore, the GC-$\gamma$ AHF is considered not to have the primary skin and eye toxicity in rabbits. In active systemic anaphylaxis (ASA) test, GC-$\gamma$ AHF and GC-$\gamma$ AHF emulsified with Freund's complete adjuvant (FCA) did not induce any symptom of anaphylactic shock in guinea pigs. In passive cutaneous anaphylxis (PCA) test, after sensitization with antisera of GC-$\gamma$ AHF sensitized mice, blue spots were observed on the hypodermis of back of rats, but diameter of each spot was smaller than 5 mm in each test groups except the positive control group. Based on the results of this study, GC-$\gamma$ AHF is not conidered to have any antigenic potential. In conclusion, at levels of up to 500 IU/kg, GC-$\gamma$ AHF did not produce treatment-related toxicity under the conditions of these acute-, four week repeated-toxicity, primary skin and eye toxicity, and antigenicity test.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.952-961
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• 2003

In the first part of the study, rates of estrus occurrence and success of A.I. service in the Thai-native and Friesian crossbred, and purebred Friesian cows fed in the National Dairy Training and Applied Research Institute in Chiang Mai, Thailand were traced monthly throughout a year. An electric fan and a water sprinkler cooled the stall for the purebred cows during the hot season (March-September). Both rates in pure Friesians were at their highest in the cold-dry season (October- February), but they decreased steadily during the hot-dry season (March-May) and were at their lowest in the hot-wet season (June-September). Seasonal change of a similar pattern was observed in the incidence of estrus, but not in the success rate of insemination in the crossbred cows. By the use of reproductive data, compiled in the same institute, on the 75 % cross- and purebred Friesian cows, and climatological data in Chiang Mai district, effects of ambient temperature and humidity on the reproductive traits of cows were examined by regression analysis in the second half of the study. Significant relationships in the crossbred, expressed by positive-linear and parabola regressions, were found between reproductive parameters such as days to the first estrus (DTFE), A.I. service (DTFAI), and conception, the number of A.I. services required for conception and some climatic factors. However, regarding this, no consistent or intelligible results were obtained in purebred cows, perhaps because electric fans and water sprinklers were used for this breed in the hot season. Among climatic factors examined, the minimum temperature (MINT) in early lactation affected reproductive activity most conspicuously. As the temperature during one or two months prior to the first estrus and A.I. service rose, DTFE and DTFAI steadily became longer, although, when MINT depleted below $17-18^{\circ}C$, the reproductive interval tended to be prolonged again on some occasions. The maximum temperature also affected DTFE and DTFAI, but only in limited conditions. The effect of humidity was not clear, although the inverse relationship between DTFE and minimum humidity during 2 months before the first estrus in the crossbred seemed to be significant. Failure to detect any definite effect of climate on the reproductive traits of pure Friesians seemed to indicate that forced ventilation by electric fans and water sprinklers were effective enough to protect the reproductive ability of this breed from the adverse effects of a hot climate.

• Korean Journal of Medicinal Crop Science
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• v.26 no.2
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• pp.157-169
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• 2018

Background: Cassia tora L., an annual or perennial plant of the Fabaceae family, is traditional medicine with various biological activities, including anti-constipation and, anti-inflammation. Chemical compounds such as anthraquinone glycoside and naphthalene derivatives have been isolated from this plant. Cassia tora L. is a common contaminant of agricultural commodities, but is toxic to cattle and poultry. Methods and Results: To investigate the potential toxicity, Cassia tora L. aqueous extract (CO) was administered orally to rats for 26 weeks at 0 (control), 300, 1,500 and 3,000 mg/kg/day (n = 10 for male rats for each dose). The positive control comprised animals orally administered anthraquinone 100 mg/kg/day. There was no treatment-related mortality. An increase in the kidney weight was observed at 3,000 mg/kg/day of CO and anthraquinone 100 mg/kg/day. Macrophage infiltration in the colon was observed at CO 1,500 and 3,000 mg/kg/day and anthraquinone 100 mg/kg/day, but there were no significant toxicological changes in the incidence and severity of the finding. Conclusions: The oral no-observed-adverse-effect level (NOAEL) of CO was 3,000 mg/kg/day in male rats and no target organs were identified. In addition, 300 mg/kg was found to be the no-observed-effect level (NOEL) for systemic toxicity under the conditions of the study.