• Atmosphere
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• v.31 no.2
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• pp.215-227
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• 2021

The necessity of the prediction on the Seasonal-to-Subseasonal (S2S) timescale continues to rise. It led a series of studies on the S2S prediction models, including the Global Seasonal Forecasting System Version 5 (GloSea5) of the Korea Meteorological Administration. By extending previous studies, the present study documents sea surface temperature (SST) prediction skill around the Korean peninsula in the GloSea5 hindcast over the period of 1991~2010. The overall SST prediction skill is about a week except for the regions where SST is not well captured at the initialized date. This limited prediction skill is partly due to the model mean biases which vary substantially from season to season. When such biases are systematically removed on daily and seasonal time scales the SST prediction skill is improved to 15 days. This improvement is mostly due to the reduced error associated with internal SST variability during model integrations. This result suggests that SST around the Korean peninsula can be reliably predicted with appropriate post-processing.

• Journal of Preventive Medicine and Public Health
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• v.7 no.2
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• pp.403-415
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• 1974

The author has investigated epidemiological features of human cases of epidemic encephalitis (E. E.) in the Republic of Korea and the status of antibody requisition in pre-and post-epidemic time. And virological and serological studies with regarding the relationship of E. E. infection between human and piglet, and field survey against its vector by means of virus isolation from mosquitoes were carried out. Finally, vaccine field trial against human population has also been evaluated in order to confirm its effectiveness. The results of the studies are summarized as follows : 1. The annual incidence of reported cases during the past 25 years (1949-1973) in the Republic of Korea has shown two patterns, one was typical cyclic incidence and the other one was irregular. Annual average morbidity and mortality rate per 100,000 population were 5.7 and 2.1 and fatality rate was 34.6% in typical cyclic years. 2. With regard to the geographical distribution of E. E., the province of Jeolla-Bug-Do illustrated the highest incidence regardless of the epidemic size. 3. The main epidemic period was between mid-August and mid-September (above 90% of the total number of cases). The first case was reported in middle of July and the epidemic ceased in late of October. 4. An analysis of the age distribution of cases of E. E., has shown that above 90% of the total cases occurred in the age groups under 14 years and it was noted that about its 54% were occurred in the age groups between 5-9 years group. 5. Through the Haemagglutination Inhibition (H-I) test for the laboratory diagnosis of E. E., it was found that higher H-I antibody titer was usually detected in the convalescent phase, 15 days after onset. 6. The H-I antibody survey against 563 healthy population by age groups during the pre-epidemic season showed that 422(75%) were less than H-I titer, 1:20 and 122(21.7%) were positive H-I titer, 1:20. Among the 94 American in Seoul who had not been in E. E. endemic area previously only one person had appeared sero-conversion as a H-I titer of 1:80 after post-epidemic season. 7. The E. E. virus could be isolated from the mosquitos pools-C, tritaeniorhyncus which were caught between late July and middle August. 8. E.E. Virus was also isolated from piglet blood on early August and H-I antibody conversion was occurred mostly on middle of August. 9. H-I antibody sero-conversion rate reached to high level when vaccine purified by mouse brain tissue inoculated, showing 98.9%. Higher antibody titer was acquired when booster inoculation was performed, Four fold rise of H-I add N-T antibodies was confirmed with 93.2% and 82.1% respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.538-545
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• 2020

This study measured the economic impact (from 2012 through the end of 2017) of the KOR-USA FTA (Free Trade Agreement) on the Korean citrus industry according to importing orange from the USA after the implementation of the KOR-USA FTA. Citrus fruits were divided into field citrus grown in open fields, house citrus grown in green houses, and late-maturing citrus (including winter season citrus) based on the cultivation methods and the varieties of citrus. We specified the structural and dynamic recursive demand-supply equilibrium models of three citrus fruits to analyze policy simulations. The results showed that for field citrus, due to the impact of some amounts of TRQ, the annual average of the real gross revenue dropped by 2.39 billion KRW between 2012 and 2017. As for house citrus, due to the impact of oranges and cherries, the annual average of the real gross revenue declined by 3.01 billion KRW between 2012 and 2017, and for late-maturing citrus (including winter season citrus), the annual average of the real gross revenue fell by 15.11 billion KRW between 2012 and 2017. This paper also suggests several policy implications.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.636-644
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• 2014

This experiment examined the effects of preharvest Ca-chitosan spraying and short-term post-harvest treatment with high $pCO_2$ on the shelf-life of 'Seolhyang' strawberry fruit. Fruit firmness decreased when harvested late in the season and was little affected by Ca-chitosan spray treatments. Short-term treatment with high $pCO_2$ after harvest, however, significantly increased fruit firmness regardless of preharvest treatment. The combined treatment of Ca-chitosan spray and high $pCO_2$ led to an additional increase in shelf-life through delay of skin disorder, fruit decay incidence and firmness loss during simulated marketing. The residual effects of both treatments, however, were reduced when fruit were harvested late in the season. Fruit firmness was more affected by high $pCO_2$ treatment whereas decay and visual quality were affected by preharvest spraying with Ca-chitosan. Although more research is required to determine the optimum concentration of calcium and chitosan, and the optimal spray interval, our results show that the combined treatment of preharvest Ca-chitosan spray and postharvest high $pCO_2$ is effective in improving strawberry fruit shelf-life by increasing firmness and delaying decay.

• Journal of Digital Contents Society
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• v.12 no.3
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• pp.271-277
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• 2011

This research studied 249 patients who has an aneurysm and went through computerized CT angiography at S University Hospital in Northern Kyung-sang area from October 1st 2008 to September 30th 2010, and the results are the following. Among total 249 of research objects, 159 women (63.9%) showed higher distribution than 90 men (36.1%) The order of the distribution of aneurysm classified by blood vessel is the following. Posterior communicating artery 34.9% as the highest, internal carotid artery 21.7%, middle cerebral artery of 15.7%, anterior communicating artery 14.5%, posterior cerebral artery and posterior cerebral artery channel 3.6% each, anterior cerebral artery and vertebral artery 2.4% each, and posterior inferior cerebellar artery 1.2%. As a result of analysis of distribution of aneurysm classified by gender, there was no case of posterior cerebral artery and posterior cerebral artery channel among men, and there was no case of posterior inferior cerebellar artery among women. Distribution of aneurysm classified by vessel according to gender showed no statistic significance. (p<0.05). And distribution of aneurysm classified by vessel according to the age, showed no statistic significance. (p>0.05), After applying post analysis to understand the group with age difference, the significance was the highest among the group of 61-70, (4.21), and the group of the age under 30 was the lowest. (2.0) There was statistic significance on the distribution of aneurysm classified by vessel according to the season. (p<0.05). After applying post-analysis in order to understand the groups with difference between seasons, it was found that fall was the highest (4.55) and spring was the lowest. (2.50)

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.620-628
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• 2012

This study addressed the influence of forest harvesting on seasonal water table dynamics in small headwater riparian areas. Four treatments including potential Best Management Practices(BMPs) for ephemeral and intermittent streams were implemented(BMP1, BMP2, clearcut and reference). Water table measurements were obtained at bi-monthly intervals for 3 years including one year of pre- and two years of post-harvest observations. Overall, water table responses affected largely by rainfall amount. In addition, significant increases in water table levels following harvesting occurred throughout the two post-harvest years. Water table levels increased up to 28.2cm in the clearcut treatment during 2008 and up to 54.2cm in BMP2 during 2009. However, increase in water table elevation was not directly related to basal area removal despite considerable differences in basal area removed between BMP2 and clearcut treatments. Water table rises were apparent in that water table were more elevated during dry season(June through November) than during wet season(December through May). These seasonal fluctuations were presumably driven by changes in evapotranspiration caused by differences in leaf area of overstory canopy and understory following harvest.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.345-356
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• 2012

We investigated the changes of fruit quality parameters, polysaccharide contents and cell wall components during maturation and ripening of two Korean pear cultivar 'Hanareum' and 'Manpungbae' compared with 'Niitaka' pear (Pyrus pyrifolia Nakai) which showed different physiological maturity based on days after full bloom (DAFB). Flesh firmness decreased continuously with fruit development and maturation, reaching a final level of 29.4, 33.5, and 27.4N at maturity in 'Hanareum' (127 DAFB), 'Manpungbae' (163 DAFB), and 'Niitaka' (170 DAFB), respectively. The level of ethylene production was very low in early season 'Hanareum' pear which showed at most 0.39 ${\mu}L{\cdot}L^{-1}$ at maturity and no ethylene was detected in 'Manpungbae' and 'Niitaka' at maturity. Fructose was the most abundant soluble sugar during fruit maturation in the pears tested and an increase of sucrose was observed during fruit ripening in the Asian pears commonly. Ethanol insoluble solids (EIS) content decreased gradually with different levels among the pear cultivars as fruit ripens consisted of 10.79, 12.72, and 12.75 $mg{\cdot}g^{-1}$ FW. The amount of total soluble polyuronides was higher in early season cultivars 'Hanareum' than those of mid-season cultivar 'Manpungbae' and 'Niitaka'. In 'Niitaka' which harvested most late season, the level of 4% KOH soluble hemicelluloses was lower than 'Hanareum' and 'Manpungbae' and maintained constantly during fruit ripening period. Cellulosic residues were determined high level in 'Niitaka' which showed 612.33 ${\mu}g{\cdot}mg^{-1}$ EIS at maturity when compared with 'Hanareum' (408.0 ${\mu}g{\cdot}mg^{-1}$ EIS) and 'Manpungbae' (538.67 ${\mu}g{\cdot}mg^{-1}$ EIS). The main constituents of cell wall neutral sugars which consisted of arabinose, xylose, galactose, and glucose were decreased gradually with onset of fruit ripening regardless of cultivar. Arabinose which was predominant in 'Hanareum' pear decreased at the last stage of ripening, but the changes of cell wall neutral sugar during ripening were not occurred in 'Niitaka' pear. The change of molecular mass distribution in water soluble pectin observed dominantly at the early stage of fruit development. Depolymerization of 4% KOH-soluble hemicelluloses and degradation of xyloglucan showed in early-season cultivar 'Hanareum' during fruit maturation, and degradation of those fractions were detected only at the early stage fruit development in mid-season cultivar 'Manpungbae' and 'Niitaka'. The molecular mass profile of CDTA soluble pectin, $Na_2CO_3$-SP and 24% KOH soluble hemicelluloses showed no significant change during fruit maturation regardless of cultivar.

• Korean Journal of Animal Reproduction
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• v.7 no.2
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• pp.57-71
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• 1983

1. Diluted chicken semen can be preserved at 2 to 5$^{\circ}C$ for 24 to 48 hr with resultant fertility of greater than 90% of that of fresh semen. Turkey semen can be preserved at 10 to 15$^{\circ}C$ for 6 to 24 hr and provide economical fertility. 2. Frozen chicken semen has given variable results; a 21 to 93% fertility ranges as compared to 92 to 94% expected with fresh semen. Highest fertility levels obtained with frozen turkey semen intravaginally inseminated have been 61 and 63% using DMSO and glycerol, respectively, as cryoprotectants. 3. The use of glycerol as a cryoprotectant reauires that its concentration in semen be reduced to less than 2% either by dialysis or centrifugation after thawing and before intravaginal insemination if optimal fertility is to be obtained. 4. The temperature at which cryoprotectants are added to semen and the time allowed for equilibration are important for subsequent fertility pre- and post-freezing. 5. The type of container used for packaging the semen, freeze or cooling rates, thaw rates and level of cryoprotectant all interact in affecting cell survival. 6. Plastic freeze straws as a packaging device for semen offers the following advantages: easy to handle, require minimal storage space, offer a wide range of freeze and thaw rates, and insemination can be made directly from them upon thawing. 7. Controlled slow cooling rates of 1 to 8$^{\circ}C$/min have thus far provided the best results for cooling chicken semen throught the transition phase change (liquid to solid) or critical temperature range of ＋5 to -20 or -35$^{\circ}C$. 8. Highest fertilities have been achieved with frozen chicken semen where a slow thaw rate (2。 to 5$^{\circ}C$) has been used regardless of the freeze rate. 9. To maintain a constant high level of fertility throughout a breeding season with frozen semen, a higher absolute number of spermatozoa must be inseminated (2 to 3 times as many) as compared to fresh semen since a, pp.oximately 50% are destroyed during processing and freezing. 10. The quality of semen may vary with season and age of the male. Such changes in sperm quality could be accentuated by storage effects. Thus, the correct number of spermatozoa may very well vary during the course of a breeding period. 11. As to time of insemination, it is best to avoid inseminating chicken hens within 1-2 hr after or 3-5 hr before oviposition; and turkey hens during or 7-10 hr before oviposition. 12. The physiological receptiveness of the oviduct at the time of insemination is a very important biological factor influencing fertility levels throughout the breeding season.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.99-107
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• 1989

The study was conducted to obtain some basic information to establish the system of performance-tests and selection of honeybee queens(Apis mellifera) under Korean circumstances, Colony performances were tested with thirty colonies of Apis mellifera at two apiaries in Taegu, Korea from September, 1988 to August 1989. The results of performance-testing on the colonies are summarized as follows : The colony weight measured before wintering was averaged $23.6{\pm}1.90kg$ and the colony weight was decreased by $2.9{\pm}0.82kg$ in average during winter season. Thirteen colonies were entered in two story hive from thirty single box colonies from April 17 to May 5, 1989 with increase of bee population and, consequently, the ability of enter-supers of the colonies apperared to be low. The ability of collecting pollen was measured to be $14.8{\pm}2.15gr$ per colony during 24 hours in April, and the number of swarm cells was counted $12.5{\pm}3.43$ cells per colony in aveage. Tendency to use propolis appeared to be moderate, and the number of returning foragers for a minute per colony was counted $108.7{\pm}18.31$ bees in average. Brood area was measured $2,464{\pm}628,67cm^2$ per colony in the post nectar flow season of acasia, and 30.8 percent of the colonies appeared to be infected with chalkbrood disease, The amount of honey production was $14.9{\pm}8.49kg$ per colony, which was harvested two times during the main nectar flow season of acasia.

• The Korean Journal of Malacology
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• v.28 no.3
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• pp.215-223
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• 2012

The ecophysiological characteristics of the oyster Crassostrea gigas in Taean area, west coast of Korea, were investigated after main spawning season from September 2011 to January 2012 to confirm the recovery process of condition. The cupped oysters, from 4 different off-bottom culture areas were compared the gonad indices, histological analysis combined with measurement of RNA/DNA contents and ratios in gonad of each sex were undertaken. To evaluate the health condition of oyster after spawning, the RNA/DNA ratio in adductor muscle, fatness and condition index (CI) were used. The results showed that cupped oysters cultured in Uihang coastal area were different physiological aspects than other experiment areas, namely continuously decreasing RNA/DNA content and ratio in adductor muscle, lowest CI and fatness. Oysters cultured in Iwon Station 1 and 2 showed fast recovery in RNA/DNA, increase in fatness and CI during post-spawning stage until October rapidly and there after it decreased. Oysters in Shinduri showed rapidly decrease in fatness and CI until October. On the contrary to this factors, RNA/DNA ratio in adductor muscle increased as like protein until October. Partially spawning season could be observed until December in Shinduri and Iwon Station 1.