• Korean journal of food and cookery science
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• v.15 no.1
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• pp.16-22
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• 1999

The relation between food intakes and dental caries was investigated with 211 primary school students (83 boys and 128 girls) in Kumsan area. The results were as follows. The rate of dental caries of the subjects was 65.4%. 83.9% of the subjects had a snack, 69.5% of students having a snack and 44.1% of students having not snack was dental caries (p<0.001). For tooth brushing numbers per day, 38.4% of subjects was one time, and 61.6% was more than two times. For tooth brushing time, 31.8% had before meals and 68.2% after meals. The intake frequency rate of main food was cooked rice 33.30%, ramyun 14.81%, bread 9.57%, rice cake 6.16%, nodule 4.88% in good group, and cooked rice 27.04%, rice cake 12.04%, ramyun 8.50%, bread 8.11%, fried rice 5.49% in dental caries group. The intake frequency rate of a side dish was kimchi 13.88%, egg 6.21%, dried laver 5.51%, fish paste 5.51%, fish 5.03%, kongjaban 0.44% in good group, and potato soup 6.86%, cucumber 6.56%, sprout soup 5.78%, bean curd 5.33%, sesame leaf 5.21%, lettuce 1.23% in dental caries group. The intake frequency rate for snack was ice cream 9.85%, biscuit 7.35%, gum 6.17%, chestnut 6.16%, apple 5.81%, milk 5.56%, yogurt 4.86%, gypo 4.39%, candy 4.15%, chocolete 3.91% in good group, and biscuit 10.00%, ice cream 6.75%, candy 5.88%, fruit canned food 5.70%, milk 5.41%, corn 5.00%, banana 5.00%, peanut 4.42%, fritter 4.39% in dental caries group. The rate of cariogenic food, detergent food, protective food in a side dish were 4.0%, 40.8%, 55.1%o in good group, and 11.5%, 43.9%, 44.6% in dental group respectively (p<0.001). The rate of cariogenic food, detergent food, protective food in a snack 67.8%, 10.4%, 21.7% in good caries group, and 75.3%, 8.8%, 15.9% in dental caries group respectively (p＜0.001).

• Journal of Sericultural and Entomological Science
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• v.47 no.1
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• pp.12-17
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• 2005

To develop technique for the production of P. tenuipes stromata on a large scale, the infection of P. tenuipes and the growth of stroma were investigated by silkworm (Bombyx mori) variety. Also, studied about biological activites of fruiting body formed on silkworm. Infection rate of the 5th instar larvae of the silkworm with P. tenuipes was the highest in Yangwonjam, followed by Hachojam, Baegokjam and Chilbojam in that order. Also, as the inoculation times was increased, infection rate tended to be raised. The rate of fruiting body formation of the silkworm pupae infected with P. tenuipes was the highest in Baegokjam, followed by Yangwonjam and Chilbojam in the order. But, actually the fruiting body formation of the 5th instar larvae of the silkworm tested was good in Chilbojam, followed by Yangwonjam and Baegokjam in that order in 3 times spraying inoculation. The fruiting bodies of Yangwonjam and Chilbojam infected with P. tenuipes had high amount of Mannitol, but Baegokjam and Hachojam had high concentration of Glucose on a dry weight basis. The mean content of total amino acid in the fruiting bodies of P. tenuipes was 1.03 ${\mu}mole/g$. The distribution rate of amino acid components decreased in the order of Arginine (12.2%)>Glycine (10.5%)> Proline (9.6)>Tyrosine (8.9%)>Serine>Leucine>Threonine. The most abundant amino acid in the fruiting bodies of the Baegokjam, Chilbojam and Hachojam infected with P. tenuipes was arginine, while Yangwonjam was Glycine. The most abundant fatty acid in P.tenuipes was Oleic acid on a dry weight basis. The unsaturated fatty acids such as Oleic acid, Linoleic acid and Linolenic acid accounted for more than 78% of the total fatty acids.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.825-832
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• 2020

The detection of estrus is very important for the successful reproductive efficiency of cattle. This has prompted the development of electronic estrus detection techniques by using the characterization of estrus behavior. The objective of this study was to investigate the changes in physical activity, mounting behavior and vocalization during estrus in Hanwoo (Korean native cattle). Bio-telemetry devices were attached to 4 multiparous Hanwoo and physical activity was compared, namely mounting behavior and vocalization for 6 days (from 2 days before the day of estrus to 3 days after the day of estrus). Physical activity rapidly increased on the day of estrus (p<0.001) and was frequently observed at night time. Mounting behavior gradually increased, starting from 2 days before the day of estrus and reached its highest level on the day of estrus (p<0.01). The circadian rhythm showed irregularities during this entire period (p>0.05). There was no significant difference in vocalization during the experiment period (p>0.05). In conclusion, we assumed that mounting behavior is an early indicator to detect estrus in Hanwoo and if both mounting behavior and physical activity are considered together it would be possible to detect estrus with a higher probability. Further studies with more information from different sources regarding the measuring of estrus in Hanwoo are needed.

• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.26-31
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• 2008

This experiment were conducted to investigate the response of growth and yield of potato after transplanting of plug seedlings 'Superior' and 'Dejima' produced at different plug cell size (105, 162, and 288) and photoperiod (8/16, 12/12, and 16/8, day/night) for 20 days in controlled plant growth system. Growth and relative growth rate of plug seedling 'Superior' was affected by plug cell size and photoperiod at 7weeks after transplanting. Tuber weight of 'Superior' was increased as cell size and photoperiod increased. That of 'Dejima' was highest in 105 cell and different with photoperiod. At 90 days after transplanting, tuber weight ($258.9{\sim}471.9\;g/plant) of 'Superior' was high in 105 and 162 cell size and 16/8 hr photoperiod. That ($278.2{\sim}428.0\;g/plant$) of 'Dejima' was high in 105 cell size, but was not different with photoperiod. The number of tuber per plant was $2.6{\sim}6.9$ of 'Superior' and $2.2{\sim}3.6$ 'Dejima'. Tuber number per plant was not significantly different with cell size and photoperiod. The large tuber over 80 g was $32.0{\sim}50.9%$ of 'Superior' and $41.0{\sim}56.7%$ of 'Dejima'. The large tuber in 'Superior' and 'Dejima' lowered as the cell size decreased. The large tuber of 'Superior' increased as photoperiod increased, but that of 'Dejima' was not differed. As the results, the optimal plug cell size and photoperiod of potato seedling is considered to be below 162 cell and over 12 hr of photoperiod.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.47-57
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• 2006

This study was carried out to select the Eco-tree for successful phytoremediation of abandoned metalliferous mines. We examined vegetation and heavy metal concentrations of woody plants in abandoned mining areas, and also conducted seed germination and seedling growth experiment on contaminated soils from Gahak and Geumjeong mines. Pinus densiflora, Robinia pseudoacacia, Lespedeza bicolor and Alnus japonica showed high frequency in the survey areas and had high heavy metal concentrations compared to other species. Heavy metal concentrations were higher in roots than in leaves and stems. The seed germination rate was in the order of P. densiflora, L. bicolor, R. pseudoacacia, and Alnus japonica from the incubactor and greenhouse experiment. In the incubator experiment germination rate was highest in the control soil for P. densiflora and A. japonica. Germination rate of P. densiflora was highest on the 100% contaminated soil for Gahak mine while germination rate decreased with increased percentage of contaminated soil for Geumjeong mine. In the greenhouse experiment germination rate was lowest on the 40% contaminated soil for Gahak mine while germination rate was lowest on the 20% contaminated soil for Geumjeong mine and increased with increased percentage of contaminated soil. Shoot growth was highest for L. bicolor while root growth was highest for R. pseudoacacia except for 20% contaminated soil in Geumjeong mine.

• Journal of Environmental Impact Assessment
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• v.25 no.6
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• pp.514-524
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• 2016

The Bio-Climatic impact Assessment System, BioCAS was utilized to produce analysis maps of daily maximum perceived temperature ($PT_{max}$) and excess mortality ($r_{EM}$) over the entire Seoul area on a heat wave event. The spatial resolution was 25 m and the Aug. 5, 2012 was the selected heat event date. The analyzed results were evaluated by comparing with observed health impact data - mortality and morbidity - during heat waves in 2004-2013 and 2006-2011,respectively. They were aggregated for 25 districts in Seoul. Spatial resolution of the comparison was equalized to district to match the lower data resolution of mortality and morbidity. Spatial maximum, minimum, average, and total of $PT_{max}$ and $r_{EM}$ were generated and correlated to the health impact data of mortality and morbidity. Correlation results show that the spatial averages of $PT_{max}$ and $r_{EM}$ were not able to explain the observed health impact. Instead, spatial minimum and maximum of $PT_{max}$ were correlated with mortality (r=0.53) and morbidity (r=0.42),respectively. Spatial maximum of $PT_{max}$, determined by building density, affected increasing morbidity at daytime by heat-related diseases such as sunstroke, whereas spatial minimum, determined by vegetation, affected decreasing mortality at nighttime by reducing heat stress. On the other hand, spatial maximum of $r_{EM}$ was correlated with morbidity (r=0.52) but not with mortality. It may have been affected by the limit of district-level irregularity such as difference in base-line heat vulnerability due to the age structure of the population. Areal distribution of the heat impact by local building and vegetation, such as spatial maximum and minimum, was more important than spatial mean. Such high resolution analyses are able to produce quantitative results in health impact and can also be used for economic analyses of localized urban development.

• Journal of Astronomy and Space Sciences
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• v.25 no.1
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• pp.33-42
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• 2008

By analyzing the observations from a number of ground- and space-based instruments, including ionosonde, magnetometers, and ACE interplanetary data, we examine the response of the ionospheric TEC over Korea during 2003 magnetic storms. We found that the variation of vertical TEC is correlated with the southward turning of the interplanetary magnetic field $B_z$. It is suggested that the electric fields produced by the dynamo process in the high-latitude region and the prompt penetration in the low- latitude region are responsible for TEC increases. During the June 16 event, dayside TEC values increase more than 15%. And the ionospheric F2-layer peak height (hmF2) was ${\sim}300km$ higher and the vertical $E{\times}B$ drift (estimated from ground-based magnetometer equatorial electrojet delta H) showed downward drift, which may be due to the ionospheric disturbance dynamo electric field produced by the large amount of energy dissipation into high-latitude regions. In contrast, during November 20 event, the nightside TEC increases may be due to the prompt penetration westward electric field. The ionospheric F2-layer peak height was below 200km and the vertical $E{\times}B$ drift showed downward drift. Also, a strong correlation is observed between enhanced vertical TEC and enhaaced interplanetary electric field. It is shown that, even though TEC increases are caused by the different processes, the electric field disturbances in the ionosphere play an important role in the variation of TEC over Korea.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.329-336
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• 2014

As an abiotic stress, chilling stress is one of the major factors limiting plant growth and increasing susceptibility to pathogens. Therefore, enhancing stress tolerance in plants is an important strategy for their survival under unfavorable environmental conditions. The objective of this study was to determine the effects of the exogenous application of salicylic acid (SA) or nitric oxide (NO) on chilling tolerance in pepper seedlings. Pepper (Capsicum annuum L. 'kidaemanbal') seedlings were grown under normal growing conditions ($20/25^{\circ}C$, 15 hours photoperiod, $145{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, fluorescence lamps) for 23 days after transplanting. The solution (3 mL) of 1 mM SA and 0.3 mM NO with surfactant triton 0.1% were sprayed two times a week, respectively. Right after the completion of chemical application, seedlings were subjected to chilling condition at $4^{\circ}C$ for 6 hours under dark condition and then the seedlings were recovered at the normal growing conditions for 2 days. In order to assess plant tolerance against chilling stress, growth characteristics, chlorophyll fluorescence (Fv/Fm), and membrane permeability were determined after chilling stress imposition. Total phenolic concentration and antioxidant capacity were measured during the whole experimental period. Disease incidence for pepper bacterial spot and wilt was also analyzed. Pepper seedlings treated with SA or NO were maintained similar dry mass ratio, while the value in control increased caused by chilling stress suggesting relatively more water loss in control plants. Electrolyte leakage of pepper seedlings treated with SA or NO was lower than that of control 2 days after chilling treatment. Fv/Fm rapidly decreased after chilling stress in control while the value of SA or NO was maintained about 0.8. SA increased higher total phenolic concentration and antioxidant capacity than NO and control during chemical treatment. In addition, increase in total phenolic concentration was observed after chilling stress in control and NO treatment. SA had an effect on the reduction of bacterial wilt in pepper seedlings. The results from this study revealed that pre-treatment with SA or NO using foliar spray was effective in chilling tolerance and the reduction of disease incidence in pepper seedlings.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.300-308
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• 2014

The purpose of this study was to investigate the night eating habits of middle schoolers. A total of 705 middle school students residing in Gyeonggi were surveyed about their dietary habits related to night eating. Among the total subjects, 59.9% (n=422) had night eating more than once a week and were classified into a night eating group (NEG). The main reason for night eating was hunger (79.1% of NEG) and the highest proportion of night eating was related to food purchased by family (39.3% of NEG). Most of the NEG had night eating in their home with family members, and the time with highest frequency of night eating was between 10 p.m. and 11 p.m.. About 33% of the NEG went to bed within an hour after night eating and 69.2% of the NEG did not report any change after night eating. The most common factors considered when choosing a night eating menu, in order of frequency, were taste, hygiene, and amount. The favorite items on the night eating menu were frozen desserts, fresh fruits, chicken, fruit juice, Ramen, pizza, and Jajangmyeon. The most frequent menu choices were fresh fruits, frozen desserts, Ramen, chicken, yogurt, and fruit juice. The NEG had higher scores for picky eating (P<0.01), overeating (P<0.01), salty eating (P<0.01), and irregular meal times (P<0.001) compared to the non-NEG. Consequently, the NEG had more dietary problems than the non-NEG and their night eating behaviors were related to family habits. Night eating was mainly dominated by a diet of carbohydrates and fats, and the intake frequency and preference for foods with low nutritional value were high; thus, a practical and systematical nutrition education is required. Seasonal and comparative studies on night eating status according to various times and amounts of night eating are also required.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.2
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• pp.70-80
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• 2003

We report the first direct measurement of $CO_2$ flux over Kwangneung broadleaf deciduous forest, one of the tower flux sites in KoFlux network. Eddy covariance system was installed on a 30 m tower along with other meteorological instruments from June to August in 2002. Although the study site was non-ideal (with valley-like terrain), turbulence characteristics from limited wind directions (i.e., 90$\pm$45$^{\circ}$) was not significantly different from those obtained at simple, homogeneous terrains with an ideal fetch. Despite very low rate of data retrieval, preliminary results from our analysis are encouraging and worthy of further investigation. Ignoring the role of advection terms, the averaged net ecosystem exchange (NEE) of $CO_2$ ranged from -1.2 to 0.7 mg m$^{-2}$ s$^{-1}$ from June to August in 2002. The effect of weak turbulence on nocturnal NEE was examined in terms of friction velocity (u*) along with the estimation of storage term. The effect of low uf u* NEE was obvious with a threshold value of about 0.2 m s$^{-1}$ . The contribution of storage term to nocturnal NEE was insignificant; suggesting that the $CO_2$ stored within the forest canopy at night was probably removed by the drainage flow along the hilly terrain. This could be also an artifact of uncertainty in calculations of storage term based on a single-level concentration. The hyperbolic light response curves explained ＞80% of variation in the observed NEE, indicating that $CO_2$ exchange at the site was notably light-dependent. Such a relationship can be used effectively in filling up the missing gaps in NEE data through the season. Finally, a simple scaling analysis based on a linear flow model suggested that advection might play a significant role in NEE evaluation at this site.