• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.2
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• pp.298-317
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• 2019

The physical characteristics of the Ulleung Warm Eddy (UWE) and its relationship with the East Korea Warm Current (EKWC) were analyzed using the CMEMS (Copernicus Marine Environment Monitoring Service) satellite altimetry data and the CTD data of the National Institute of Fisheries Science (NIFS) near the Ulleung Basin from 1993 to 2017. The distribution of the UWEs coupled with EKWC accounts for 81% of the total number of the UWEs. Only 7% of the total eddies are completely separated from the EKWC. The UWE has the characteristics of high temperature and high salinity water inside of it when it is formed from the EKWC. However, when the UWE is wintering, its internal structure changes greatly. In the winter, surface homogeneous layer of $10^{\circ}C$ and 34.2 psu inside of the UWE is produced by vertical convection from sea-surface cooling, and deepened to a maximum depth of approximately 250 m in early spring. In summer, the UWE changes into a structure with a stratified structure in the upper layer within a depth of 100 m and a homogeneous layer made in winter in the lower layer. 62 UWEs were produced for 25 years from 1993 to 2017. on average, 2.5 UWEs were formed annually, and the average life span was 259 days (approximately 8.6 months). The average size of the UWEs is 98 km in the east-west direction and 109 km in the north-south direction. The average size of UWE using satellite altimetric data is estimated to be 1~25 km smaller than that using water temperature cross-sectional data.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.61-70
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• 2019

"Jungmo2510", a rye cultivar, Secale cereal L., was developed by National Institute of Crop Science, RDA in 2015. It was developed from open pollination from within 10 rye cultivars or lines including "Chochun" in 1995. The line "SR95POP-S1-523-1-5-5-4-7-3-B-16-3-19" was selected for its excellent agronomic appearance and was placed in yield trials for two years from 2011 to 2012. The line was designated "Homil55" and was placed in regional yield trials at the four locations around Korea from 2013 to 2015, during which time the name "Jungmo2510" was given. This cultivar is an erect plant type and leaves of short and broad size with a green color, a yellow colored, medium-diameter culm, and a yellowish brown-colored, medium-size grain. The heading date of "Jungmo2510" was April 16, which were 2 days earlier than that of "Gogu". "Jungmo2510" also showed similar to winter hardiness and greater resistance to lodging compared to those of the check cultivar. Over three years, the average dry matter yield of "Jungmo2510" was 802 kg 10a^-1 , which was harvested in late April and was lower than that of the check cultivar "Gogu" (825 kg). The seed productivity of "Jungmo2510" was approximately 481 kg 10a^-1 , which was 2.4% less than that of the check. "Jungmo2510" was higher to than "Gogu" in term of protein content (9.1% and 8.0%, respectively), total digestible nutrients(TDN)(57.5% and 55.5%, respectively), and TDN yield 10a^-1(419 kg and 392 kg, respectively). This cultivar is recommended as a fall sowing crop in areas where the average daily minimum-mean temperatures are higher than -12 ℃ in January, and as a winter crop for whole-crop forage before the planting of rice or green manure around Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.29 no.1
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• pp.28-41
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• 2024

The carbon balance serves as a valuable indicator of a plant's physiological status under diverse environmental conditions. We investigated the photosynthetic and respiratory responses of the Asian surfgrass Phyllospadix iwatensis along the northeast coast of the Korean peninsula in response to changing water temperature (ranging from 5℃ to 30℃) to estimate the seasonal whole-plant carbon balance through a series of incubation experiments. The maximum gross photosynthetic rate (P_max) showed a significant difference among the temperature treatments, while there was no significant difference in photosynthetic efficiency (α). The maximum gross photosynthetic rate of P. iwatensis reached its peaks at 20℃ treatment (101.65 μmol O₂ g^-1 DW h^-1) but decreased rapidly at 30℃. The saturation irradiance (I_k), compensation irradiance (I_c), and respiration rate (R) of P. iwatensis exhibited significant differences among the temperature treatments. The saturation irradiance increased up to 20-25℃ (121.59-124.50 μmol photons m^-2 s^-1) and sharply decreased at 30℃. The compensation irradiance and respiration rate increased steadily with rising water temperature. The ratio of P_max to R (P_max:R ratio) was the highest at 5℃ but dramatically decreased at 30℃. The whole-plant carbon balance, calculated based on photosynthetic parameters, respiration rates, and biomass, exhibited distinct seasonal variation, increasing during winter and spring and decreasing during summer and fall, which is consistent with the highest in situ growth in spring and severely limited growth at the highest water temperature conditions. Phyllospadix iwatensis displayed a negative carbon balance during late summer, fall, and winter, but demonstrated a positive carbon balance during spring and early summer. Our findings suggest that the rising seawater temperatures associated with climate change may lead to significant alterations in the seagrass ecosystem functioning along the rocky shores of the Korean east coast.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.88-99
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• 1996

In recent years dry direct-seeding of rice has been encouraged by the government and increasingly practiced by farmers in Korea. This has been bringing up an increased occurrence of weedy rites. Some farmers in the southern region dare to sow the rice before winter after harvest, while most farmers wish to sow as early as possible in the spring to secure the growing period, and to disperse the intensive labor in early May. The purpose of this study was to determine the feasibility of moving the sowing of rice to an earlier date under dry direct-seeding, and to elucidate the nature of emergence of an old strain of rice, weedy rites, and barnyardgrasses tinder this farming practice and their adaptive competence over present cultivate. The presently recommended rice cultivar, Dongjinbyo and an old rice strain, Dadajo which prevailed in early 1900s, almost could not emerge from soil deeper than 6cm and could emerge to only 5.3% at best from 1cm deep loamy soil field when the seeds were sown on Nov. 28. However, two strains of weedy rites being weedy for over 200 years emerged by 17.0 to 63.0% from the loamy and sandy clay loam field 1 to 6cm deep. Emergence of the weedy rites was greater in the loamy soil and at a shallow depth, and negligible from the soil depth of 9cm. Barnyardgrasses sown on Nov. 28 emerged by 13.4 to 51 % from the 1 to 3cm deep loamy soil, and 8.6 to 46.7% from the 1cm deep sandy clay loam. Echinochloa crus-galli var. crus-galli emerged more than var. praticola, and var. oryzicola least. Most of the non-emerged barnyardgrasses seem to have entered secondary dormancy. Seeding rice a month earlier than the season lowered the emergence of Dongjinbyo by ca. 10, 18, and 26%, respectively at 1, 3, and 6cm soil depths, indicating that moving the seeding date a month earlier is impractical. The old strain, Dadajo sown in the soil at a depth of 6cm responded similarly. However, the strain has shown a significantly higher ability in emergence from 9cm deep soil. Weedy rices sown a month earlier A month earlier sown weedy rices have shown very similar emergence rates at various soil depths to those sown on May 1. Barnyardgrasses have also shown similar emergence rates when sown between April 3 and May 1. Like barnyardgrasses, the old strain and weedy rices apparantly posessed a greater adaptability to emerge under lower temperatures, and from deeper soil ; Dongjinbyo${\leq}$ Echinochloa species in that order. However, emergence- speed under lower temperature(sown on April 3) was faster in the order of weedy rice

• Korean Journal of Veterinary Service
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• v.38 no.3
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• pp.155-162
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• 2015

The incidence of second-grade milk production in 9 dairy farms of South Korea was investigated from May 2011 to March 2012, and the serum composition of cows producing first- and second-grade milk in 14 farms including the 9 farms was analyzed. The incidence rate of second-grade milk production of 402 cows in nine dairy farms located in the central and southwestern regions of Korea was 15.4% with the highest rate being 34.4%. Seasonal morbidity was higher during late winter (February) and early summer (June) with the highest rate observed in February (32.6%) followed by November (33.3%). Second-grade milk was most frequently found within one month postpartum (34.1%) while only 3.5% was found during the first 60~90 days of lactating period (n=785, 5 herds). The morbidity increased thereafter (P<0.05) with the highest observed between 270~300 days of lactation (36.1%). The acidity was not significantly different between second-grade ($0.159{\pm}0.026%$) and first-grade milk ($0.158{\pm}0.027%$). Blood serum analysis of 371 cows in the 14 dairy farms indicated that aspartate aminotransferase (AST) level was significantly higher (P<0.001) in cows producing second-grade milk while albumin was significantly lower (P<0.001) than cows producing first-grade milk. Total protein and triglyceride was also significantly low along with glucose, non-esterified fatty acid and blood urea nitrogen in cows producing second-grade milk. Statistical analysis including sensitivity, specificity and positive/negative prediction values showed that lactating cows with high AST, low albumin, total protein and triglyceride levels in the serum tended to produce second-grade milk. It was concluded that serological parameters, especially live functional and metabolic-related serum compositions (AST, albumin, total protein and triglyceride), were significantly influenced in cows producing second-grade milk.

• Korean Journal of Veterinary Research
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• v.27 no.2
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• pp.321-330
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• 1987

In the endemic area of bovine piroplasmosis in Chonbuk Province, total of 486 heads of Holstein cow selected from 14 farms randomly were examined the infection status of piroplasma and their blood values. The results obtained were summarized as follows: 1. The etiological agent was only Theileria sergenti and none of the Babesia sp. infection. 2. All of the 486 heads of examined cow were infected with Theileria sergenti (100%). 3. In the initial examination of 11 farms in early summer, the means of blood values were as follows; RBC:$526{\pm}84(10^4/mm^3$), Ht:$27.9{\pm}2.8%$, SP:$7.5{\pm}0.6g/dl$, WBC: $11586{\pm}354/mm^3$, and Fibrinogen: $578.5{\pm}164.1mg/dl$. 4. In the second examinations in slimmer season, the blood values of examined cows had little varieties. But in the winter season, cows housed in the barn, the blood values were greatly increased; RBC: $601{\pm}77(10^4/mm^3)$, (F-value: 37.186**), Ht: $30.5{\pm}1.3%$(F-value: 15.626**) Hb: $12.2{\pm}1.3g/dl$(F-value: 5.899**), SP: $7.4{\pm}0.6g/dl$(F-value: 5.05**). 5. To determine the piroplasma infection in the many herds of cow, the measurement of Ht, Hb, and SP values etc. were more effective and helpful to find the weak cow because the examined process are not only to be easily carry out many samples but also to be done very simple and rapidly. 6. The indications of therapeutic standard values were stablished as follows; the less than 20% in the Ht value, below the 10g/dl in the Hb value, and less than 6g/dl in SP value. When the one among the therapeutic standard values, Ht, Hb, and SP was below the therapeutic standard value, the cow was treated with nutriments. When more than two among them were below the therapeutic standard, the cow was treated with Berenil, at once. In this way, there was no one head which represented clinical signs of piroplasmosis among 486 heads of cow at 14 farms during the year of 1986. 7. In a Korean native cattle infected with Thieleria sergenti seriously, the recovery of blood values was very prolonged by the treatment of Berenil only. But by the transfusion of 300ml blood collected from normal cow, the blood values were recovered rapidly.

• Weed & Turfgrass Science
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• v.3 no.4
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• pp.370-377
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• 2014

Research was initiated to evaluate cool-season grass (CSG) overseeding effects on coverage and species transition in Korean lawngrass (Zoysia japonica Steud.) and to determine CSGs and their seeding rate for a practical overseeding. Treatments were comprised of Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), tall fescue (TF, Festuca arundinacea Schreb.) and their mixtures. Significant differences were observed in turfgrass coverage and species transition. Since overseeding, the coverage was highest in PR, followed by TF and lowest in KB. The highest coverage in polystand was associated with Mixture IV (TF 50 + PR 50) at a seeding rate of $150gm^{-2}$ which had highest PR and TF, but without KB. Regarding turfgrass transition, zoysiagrass recovery continued to come back up to 80% from late March. But it reduced after early October. Zoysiagrass in monostand was greatest in KB and lowest in TF, but variable in polystand. For the fast and great coverage in winter, it would be the best to apply with PR at $100gm^{-2}$ and equal combination of PR and TF by 1/2 in the mixture at $150gm^{-2}$. For the smooth spring transition to zoysiagrass, however, KB application at $50gm^{-2}$ is recommended.

• Korean journal of applied entomology
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• v.47 no.3
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• pp.201-208
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• 2008

Spring phonology of the oriental fruit moth, Grapholita molesta, was monitored using sex pheromone traps in apple cultivating areas. Their occurrence was earlier in southern areas and their population sizes were significantly different among orchards even in a local cultivating zone. The overwintering populations appeared to move between local orchards, based on the fact that monitoring data obtained at the sites between orchards were similar to those of nearby orchards. However, within orchards, these adult movements appeared to decrease and showed skewed occurrences at the side of upwind direction or close to neighboring orchards. At initial occurrence peak(April 20-25), the ovenvintering populations of the different localities were collected and analyzed in their genetic distances. PCR-RAPD analysis indicated that there were significant genetic differences among the overwintering populations of G. molesta. This genetic differentiation of overwinterin populations may be due to genetic bottleneck following differential selection pressures against the subpopulations of G. molesta during winter on the basis of the RAPD analysis that each early spring population was significantly different to its previous fall population in the same locality.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.149-155
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• 2017

In this research, the surface covered curing method using the double-layered bubble sheet was evaluated. This double-layered bubble sheet has outstanding insulating performance with its low heat conductivity and high economic feasibility with its high durability. However, in the case of wall-typed building construction, the area of exposed rebar is curious on curing performance with the double-layered bubble sheet in spite of the double-layered bubble sheet showed favorable performance for slab. Therefore, in this research, regarding the actually constructed wall-typed apartment building, the most efficient curing method was suggested based on the evaluation of curing performance depending on temperature distribution depending on various location of covered or exposed rebar. As a result, the D method was determined as the most efficient curing method without any concern of early-age frost damage. However, by considering easiness of construction, the B method of covering the pieced double-layered bubble sheet on gap between rebars can be another option of desired result.

• Journal of the Korean Geographical Society
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• v.36 no.3
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• pp.233-246
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• 2001

Topography and soil characteristics of earth hummocks are examined in the summit crater of Mt. Halla in order to evaluate their morphoclimatic significance as an indicator of a periglacial environment. The hummocks are generally oval in outline, and they have a diameter of 42 to 200 cm and a height of 9 to 27 cm Seventeen hummocks are distributed In a 5$\times$5 m quadrat at an interval of 20 to 40 cm Excavation reveals the cryoturbated soil profiles which consist of upper dark brown layer and lower brown layer. The dark brown layer has 61.8% total clay and silt content, implying Its high frost susceptibility Earth hummocks have the dry density of 0.761 to 1.009 g/㎤ the void ratio of 1420 to 2.008, and the moisture content of 24.2 to 68.8% by weight, respectively. The hummocky soils become compacted and desiccated downward. Earth hummocks are frozen as a hard solid mass during winter and early spring, and freezing fronts reach about 45 cm below their apices. The layer with high lute content appears in the upper horizon of dark brown soil. but Ice lenses are not so much segregated The moisture content of hummocky soils generally increases up to 73.9 to 118.80% for dark brown layer and 49.9 to 82.8% for brown layer during thins period Because the cohesive soil of earth hummocks indicates 72.8% of the moisture content as a liquid limit, the dark brown layer is highly fluid and consequently subject to cryoturbation processes.