• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.2
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• pp.161-168
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• 2011

The heating, ventilating, air conditioning (HVAC) system is a very important part of an automotive vehicle: it controls the microclimate inside the passenger's compartment and removes the frost or mist that is produced in cold/rainy weather. In this study, the numerical analysis of the defrost duct in an HVAC system and the de-icing pattern is carried out using commercial CFX-code. The mass flow distribution and flow structure at the outlet of the defrost duct satisfied the duct design specification. For analyzing the de-icing pattern, additional grid generation of solid domain of ice and glass is pre-defined for conductive heat transfer. The flow structure near the windshield, streakline, and temperature fields clearly indicate that the de-icing capacity of the given defrost duct configuration is excellent and that it can be operated in a stable manner. In this paper, the unsteady changes in temperature, water volume fraction, and static enthalpy at four monitoring points are discussed.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.131-144
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• 1997

Traffic jam densified day by day is phenomenon to occur lack of the road capacity in comparison with traffic density, but lack of the road cannot be concluded by main cause of traffic ism. Because the central function of a city would be concentrated upon the downtown and traffic demand would not be evenly distributed by the classification of an hour. Therefore, this study based on the fact that each driver will select the route generating traffic delay very low when path choice from origin to destination in travel plan estimating the quality of passage could be maintained the speed he want will approach to a characteristic grasp of a road, traffic, driver changing every moment by traffic-demand of road increased as a geometrical series with analysis a classification of a street, a intersection along the path on traffic density and highway capacity analysis the path using GIS techniques about complex street network, also will get the path of actual optimum for traffic delay trend creating under various condition the classification per a hour, a day of week and an incident through network such as analysis for traffic generation zone adjacent about street, intersection, afterward will expect the result increasing efficiency of the road-use through a good distribution of traffic by optimum-path choice, accordingly will prepare the scientific, objective, appropriate basis to decide the reasonable time of a road-widen and expansion through section analysis along a rate of traffic volume vs. road capacity.

• Journal of Gifted/Talented Education
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• v.26 no.4
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• pp.699-719
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• 2016

Alternate pictures that are proven to be equivalent are in high demand to assess creative thinking and language skills. This study aimed to investigate the equivalence of three pictures ('Dog owners,' 'Lost Dog,' and 'Overslept') recently developed for use in a creative writing task. Middle school students (N=183) wrote a story in English based on one of the three prompts distributed randomly. Four writing features (fluency, syntactic complexity, lexical diversity, and temporality) were analyzed with Coh-Metrix and MANCOVA. The three prompts were largely equivalent in their capacity to detect differences among writers in all the features of writing. The difficulty levels of the three prompts, however, were not necessarily the same. Two prompts, Dog Owners and Lost Dog, were verified as equivalent prompts, and therefore, they are recommended as alternate forms to assess creative language skills in repeated measurements. The Overslept prompt had greater facility in eliciting diverse words and more temporal connectives in composing stories. The differential difficulty shown among the prompts suggests that the validity of using different picture versions in repeated assessment remains questionable unless those versions undergo equivalence verification.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.171-179
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• 2024

In previous Cost-of-Illness (COI) studies, the economic impact of lost leisure time of patients has been mostly underexplored. Furthermore, few studies have focused on chronic or severe diseases, thereby inadequately addressing the segment of self-care patients who do not fall into the categories of inpatients or outpatients. In the present study, we used a comprehensive approach to calculate the annual cost of leisure loss, incorporating factors such as employment status, self-care options, and total period of leisure activity disruption. This required analyzing data from various sources, including health and labor statistics, and applying methods to accurately assess the leisure time lost due to food poisoning. The findings showed that the annual cost of leisure loss for South Korean patients with food poisoning is significant, amounting to approximately 784.5 billion KRW (702.8 million USD, USD/KRW : 1128.34). This study revealed that overlooking self-care patients and not accounting for the affected time in addition to treatment time and employment status significantly underestimated these costs. This study highlights the importance of considering a wider range of factors, including self-care, employment status, as well as the entire affected period, in assessing the societal impact of diseases such as food poisoning. These findings provide valuable insights for policymakers and healthcare professionals to understand the broader economic implications of illness and allocate healthcare resources more effectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.2
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• pp.159-168
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• 2010

This study was carried out to investigate the effects of by-product mixing silage feeding on the eating and ruminating behavior of fattening Hanwoo steer. A total of 12 Hanwoo steers (21 months old) were divided into three feeding groups and assigned to 3 dietary treatments: control (C: concentrate + ad libitum feeding of rice straw), and by-product mixing silage groups (T1: concentrate + 1 kg restricted feeding of by-product mixing silage + ad libitum feeding of rice straw, T2: concentrate + ad libitum feeding of by-product mixing silage). Eating behaviors were observed for 48 hours. Total feed intake was high in the order of T1 > C > T2, but not significantly different among the treatments. The eating and chewing time were significantly higher in C than by-product mixing silage treatments (P<0.05). Ruminating and resting time were not significantly different among the treatments. Number of bolus, number of total chews and number of chews per bolus were not significantly different among the treatments. But ruminating time per bolus and FVI (feed value index) were significantly higher in C than T1 and T2 (p<0,01, 0.05). Bolus per minute was the highest in T1 (p<0.01). Number of drinking was significantly higher in T2 than C and T1 (p<0.05), but defecating and urinating were not significantly difference among the treatments. Eating rate was the highest in T2 (p<0.05), but ruminating and chewing efficiency were not significantly difference among the treatments. Consequently, there was no big difference on eating behavior when feed by-product silage comparing with rice straw. Therefore, it is thought that by-product mixing silage could be the alternative for the rice straw.

• Clinical and Experimental Pediatrics
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• v.45 no.11
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• pp.1340-1345
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• 2002

Purpose : We studied the prevalence of snoring and its association with diseases, obesity and environmental factors, as well as sleep disturbance arising from snoring, in school-aged children. Methods : The survey was performed by a special questionnaire on 1,707 children at elementary schools from 1 to 30 July 2001 in Gwangju City. The prevalence of snoring, associated factors, and sleep disturbance were evaluated. Results : 266(16.5%) of the children snored at least once a week. 73(4.3%) of the children snored almost every day. Regarding the associated factors of snoring : There was a statistically significant difference between snoring and nonsnoring groups due to gender, obesity, sinusitis, tonsillar hypertrophy, bronchial asthma and allergic rhinitis. Of them, male gender, tonsillar hypertrophy, and obesity were significant risk factors for development of snoring. Especially, the odds ratio increased to 1.048(CI, 1.004-1.659), 1.748(CI, 1.175-2.599), and 2.266(CI, 1.300-3.950) in children with an obesity index of 20-29%, 30-49%, ${\geq}50%$, respectively. There was a statistically significant association of snoring with decreased sleep duration, sleep talking, and drowsiness during the day as a result of sleep disturbance. Conclusion : 16.5% of school-aged children snored at least once a week. The association of snoring with tonsillar hypertrophy, obesity and gender as risk factors was demonstrated in this study.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.107-115
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• 2001

Development of effective activation protocols is of great importance for improving the success of cloning and subsequent transgenic. Three methods for oocyte activation, including 5$\mu$M ionomycin (5 min) alone, ionomycin + 1.9 mM 6-dimetylaminopurine (DMAP, 3 hrs) and ionomycin + 10 $\mu\textrm{g}$/ml cycloheximide (CHX, 3 hrs) were compared for their effects of pronuclei (PN) formation, development, developmental velocity and ploidy of parthenotes to IVF control in bovine. In group of ionomycin + DMAP, the oocytes having more 3PN were significantly (P<0.05) higher than in groups of ionomycin alone and of ionomycin + CHX (45.5% vs. 0 and 0%, respectively). Activation with the ionomycin alone, ionomycin + DMAP and ionomycin + CHX resulted in cleavage rates of 30, 85.5 and 57.9%, respectively. The blastocysts rate of parthenotes activated by ionomycin + DMAP treatment was significantly higher (12.3%. p<0.05) than those of other treated groups. Chromosome analysis shows that ionomycin + DMAP treatment greatly enhances the incidence of chromosomal abnormality of the parthenotes. From the results, we may conclude that DMAP treatment to the oocytes accelerates developmental velocity resulting in both the higher incidence of chromosome abnormality and of PN formation, and strongly suggest that CHX combined with ionomycin is better than DMAP for the purpose of successful nuclear transplantation. Developmental velocity of parthenotes activated by ionomycin + DMAP treatment was significantly (P<0.05) faster than others.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.1
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• pp.41-49
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• 2016

The objective of this study was to determine the effect of different pregnancy stages on the eating and ruminating behavior of Hanwoo heifers (Bos taurus coreanae). A total of twelve Hanwoo heifers were divided into four groups depending on pregnancy stage: C: before pregnancy, 9 months old, T1: 3 months pregnant, 16 months old, T2: 6 months pregnant, 19 months old, T3: 9 months pregnant, 22 months old (3 replicates per group). Concentrate of 1% of the body weight was fed to them. Roughage was provided at ad libitum to all treatments. Our results revealed that the intake of roughage was the highest in the T3 group (at 3.68 kg) and the lowest in the C group (at 1.02 kg, p<0.05). Total intake in the order from high to low was: T3 > T2 > T1 > C (p<0.05). The rate of dry matter intake compared to body weight (DMI/BW, %) from high to low order was: T3 > T2 > T1 > C (p<0.05). Eating time, ruminating time, and chewing time were the highest in T3 group (p<0.05). Resting time was the highest in C group (p<0.05). The number of bolus and the number of total chews were significantly higher in T3 compared to those in other groups. However, ruminating time per bolus was not significantly difference among groups. The number of chews per bolus from high to low order was: C > T1 > T3 > T2 (p<0.05). The number of bolus per minute was not significantly different among groups. The number of drinking and the number of defecating were significantly higher in C and T1, respectively (p<0.05). However, the number of urinating had no effect according to pregnancy stage. Eating rate and chewing efficiency were significantly higher (p<0.05) in accordance with pregnancy stage (T3 > T2 > T1 > C). Ruminating efficiency was significantly (p<0.05) higher T1 than that in other groups.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.219-226
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• 1986

A study was conducted to provide direct comparisons of the effect of variations in herbage use, grazing and social behaviour upon the flat, slope and forest grassland with a total 30 Korean Native Cattle and 5 Korean Native Goats under 4-year old grassland established by intensive sowing method in Daecheon. The results obtained are summarized as follows; 1. Relative intake index, dry matter intake per animal and dry matter digestibility by Korean Native Goats in flat, slope and forest grassland were 35.2%-462g-63.7%, 35.0%-459g-63.0% and 29.8%-391g-62.1%, respectively. 2. Grazing time by Korean Native Cattle was not different among the grassland types, but ruminating time was increased in slope grassland, whereas in forest grassland was decreased. Resting time was increased in forest grassland, whereas in slope grassland was decreased. Walking time was increased in flat grassland, but loafing time was increased in forest grassland. The number of rumination, chews per bolus and defecation number were decreased in forest grassland. The number of drinks, total drinking water and walking distance were increased in slope grassland. 3. Animal distance, occupied area per animal and sub group formation by Korean Native Cattle in flat, slope and forest grassland were $3.4m-11.9m^2-3.6head$, $3.56m-11.0m^2-3.7head$ and $3.70m-14.6m^2-3.4head$, respectively. The order of grazing movement was similar to the pear-shaped grazing formation, but the relations of dominance between first grazer and last grazer upon different grassland types was not clear.

• Journal of Korean Society of Transportation
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• v.17 no.4
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• pp.99-110
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• 1999

With a growing awareness, transportation is the maior source of urban air pollution. Planners and policy-makers are strongly urged to care the impacts of transportation management strategies on environment. Since transport-related air Pollution can be regarded as negative externalities of transport, it is indispensable to evaluate chanties in air quality which seems to occur when proposed transport measures are implemented. In addition, transport measures should be integrated in a set of combined Paradigm regarding transport and environment. Based on the integrated Paradigm between transportation demand management(TDM) and environmental planning, the main focus is given to apply environment cost internalizing measures to the short-term congestion management Program(SCMP) in Seoul, that has been developed in 1998 by Seoul Development Institute. Three modules are analyzed: without and/or with ￦500, ￦1000 emission plus gas tax, respectively. From the empirical applications on Seoul city, one of the most exemplary findings in SCMP program is that, emission plus gas tax can be a very useful measure to reduce vehicular emissions by targeting major Pollutants differently, rather than by dealing with pollutants collectively. Further research that provides (1)showing the spatial variation of pollution levels along the intersections, (2)more developing combined Paradigm between transport, land use, and environment, (3)using environmental road capacity rather than Physical-aspects of road capacity, and (4)continuing R&D on air quality constrained TDM, can contribute significantly to applications of the real and efficient environment-constrained transportation planning.