• Journal of the Korean GEO-environmental Society
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• v.7 no.5
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• pp.49-55
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• 2006

Quick lime made from limestone that are deposited abundantly in Korea has excellent potentials for stabilization of clayey soils. If Korea is able to take advantage of its abundant supply, economical efficiency could be achieved through mass production as well as being able to take advantage of utilization of natural resources. For stabilizing of clayey soil with lime, it is necessary to determine the required quantities of lime firstly and to evaluate the degree of stabilization with lime content. In this test, the quantity of lime required for 2 clayey soils which located in Seunggok and Bugok province respectively, and for 2 clay minerals-kaolinite and montmorillonite-were determined by ASTM C 977-92 and were evaluated for solidification of each samples with changing lime contents by Atterberg limit test and pH test. It was also evaluated for the improvement of each sample with lime content and curing time. The sample which added lime content determined by ASTM C 977-92 increased plastic limit, unconfined compression strength, and decreased pH in increasing trend.

• KIEAE Journal
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• v.8 no.4
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• pp.11-18
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• 2008

This research case-study places are chosen Seoul Metropolitan City and Yong-In City where the distinction characteristics of outdoor spaces are introduced in Apartment Complex. In this study, the standard of waterscape facilities will be set through preliminary researches and detail design factors are prepared for each characteristics. Analyze and research the characteristics of design factors through the field research of places. The Group data from Cluster Analysis, which is about waterscape facilities, is analyzed and classified by types of waterscape facilities in common residence. and then each type of characteristics and representatives of waterscape facilities founded. Waterscape facilities are charactered in 4 main types. I Type is appeared to the natural artificially mountain stream, slope and a rest space type, and feelings type. This type has twenty sites. II Type is appeared to the fewest sites(11 sites). This type is appeared to the Eco-pond, Border planting next to the waterscape facilities. III Type is appeared to the largest sites(28 sites), that is, play style water facilities of no-plantation patterns. IV Type is appeared to the retaining wall type, the rest space of bench type. Research result led, detailed plan element 64 are selected with design elements Seoul Metropolitan City and the Yong-In City at the time of the fact that well is only reflected commonly from external spaces, the type by quality which leads a statistical analysis the type quality was well reflected relatively was judged.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.533-545
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• 1994

The bleeding of 39 Acer mono trunks by wounding was investigated at the altitudes of 400m, 500m, 800m, and 1100m on Wangsirobong (1,214m), Mt. Chiri area (127°34'E., 35°14'N.) from February 4 to March 21, 1993 and from February 23 to March 23, 1994. The amount of sap in a day was clodely related to the change of air temperature and wind speed. Especially, the abundant sap was exudated at the ranges of -4~13℃ in the daily range of temperature and it was below 0.14m/s in wind speed. The most abundant bleeding was exudated from Acer mono trunk located south facing slope in 800m altitude. Also the amount of sap increased with incereasing suface area of crown. The maximum bleeding of sap was collected from the hole punctured at 80cm height from the ground surface at southern part of the trunks. And the number of exudation holes had an important effect on bleeding of sap but the number of holes should be controlled by DBH of trunks. These results suggested that the exudation was influenced by the daily range of temperature and wind speed. And the altitude, direction of sloped where the trees occurred, surface area of crown, the number of exudation holes, height form the ground surface and the direction of the hole was 91.6% when germicide (Dimethyl-4,4' -ophenylene bis 3-thio alonate) was treated from April to October after bleeding of sap in the year.

• Physical Therapy Korea
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• v.10 no.1
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• pp.109-128
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• 2003

This study tested whether repeated measurement of median frequency (MDF)-related variables could express the muscle power changes during a 12-week DeLome strengthening program, by using consecutive overlapping FFT (Fast Fourier transformation) and integrated EMG (IEMG) from surface EMG data for isometric and isotonic exercise. To evaluate the effect of training, the following were recorded every 3 weeks for the elbow flexors and knee extensors of 5 healthy male volunteers: MVC, lRM, limb circumference, and surface EMG during isometric MVC or isotonic contraction at 10RM load. From the EMG data, IEMG and variables from a regression analysis between MDF and time were obtained. MVC, lRM, IEMG, and initial MDF increased linearly over the training period. The fatigue index and slope of the regression line increased temporarily until the 6th week and decreased thereafter. From these results, there appeared to be enhanced neural recruitment of fast twitch fibers in the first 6 weeks and continued enhancement in the recruitment and hypertrophy of fast twitch fibers, which led to increased fatigue resistance, over the last 6 weeks. Accordingly, the MDF and IEMG analysis technique could demonstrate the effect of the program detected significant changes in both isometric and isotonic contractions. EMG analysis methods can be used to estimate the electrophysiological and histological changes in skeletal muscles during a strengthening program.

• Ocean and Polar Research
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• v.31 no.2
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• pp.177-187
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• 2009

This study examined the multi-scale variabilities of sea surface temperature (SST) and salinity in the Japan/East Sea (JES) based on statistical analyses of observational data, with a focus on the northwestern part of the sea. The regionality of JES SST variability was estimated for different frequency ranges on semimonthly (11-17 days), monthly to seasonal (30-90 days), quasi-semiannual (157-220 days), and quasi-biennial (1.5-3 years) time scales using cluster analyses of daily gridded SST data for 1996 to 2007 from the Japan Meteorological Agency (JMA). Several significant peaks and regional cores were found in each frequency range of the SST anomaly (SSTA) oscillations. Quasi-semiannual SSTA oscillations with high amplitude were found in the south-southwestern part of the Japan Basin ($41-43^{\circ}N$) and were amplified in the area adjacent to Peter the Great Bay. Oscillations with periods of 79 and 55 days also prevailed over the southwest Japan Basin between the Yamato Rise and the continental slope. A similar method was applied to classify SST and the annual cycle of surface salinity using Generalized Digital Environmental Model (GDEM) gridded data. The Tatarskii Strait and adjacent area showed the most specific annual cycles and variability in salinity on interannual to interdecadal time scales. The most significant inverse relationship between surface salinity in the Tatarskii Strait and southern JES areas was found on the interdecadal time scale. Linkages of sea water salinity in the Tatarskii Strait with Amur River discharge and wind velocity over Amurskii Liman were also revealed.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.654-661
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• 2019

The soybean cyst nematode, Heterodera glycines, is a major plant-parasitic nematode that has caused important economic losses to Korea's soybean production. Four species of cyst nematodes, H. schachtii, H. glycines, H. trifolii, and H. sojae, all belong to schachtii group are coexist in field soil in Korea. The rapid identification of the nematode is crucial for preventing crop damage and in decision making for controlling this nematode. This study aimed to develop a species-specific primer set for quantitative PCR (qPCR) assay of H. glycines. The specific primer set (HGF1 and HGR1) for H. glycines was designed based on the cytochrome c oxidase subunit I (COI) sequence of mitochondrial DNA. After optimization, it is possible to identify the H. glycines using a qPCR assay with DNA extracted from a single cyst and single second-stage juvenile (J2). The specificity was confirmed by the absence of SYBR fluorescent signals of three other Heterodera species. A serial dilution of DNA extracted from a single cyst was obtained for the sensitivity test. The result showed that the standard curve of the test had a highly significant linearity between DNA concentration and Ct value (R² = 0.996, slope = -3.49) and that the detection limit concentration of DNA of the primer set was 10 pg of DNA per reaction. Our findings suggested that H. glycines could be distinguished from H. sojae and other Heterodera species when a qPCR assay is used with a specific primer set.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.272-272
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• 2017

Recently, consumer's demands are increasing for new natural functional and healthful food. These demands have encouraged a better understanding of the biochemical, chemical and nutritional composition of plant products. Superhongmi rice variety was derived from a cross between CG2-3-5-2-6-2 (Heugjinju/Suwon 425) having reddish brown color and Daeribbyeo 1 having a large grain size. Superhongmi rice headed on Sep. 5th and has 94.7 cm culm length. Taxifolin, a phenolic compound in superhongmi rice extract had high ${\alpha}-glucosidase$ inhibitory activity. The ${\alpha}-glucosidase$ inhibitory activity of the superhongmi rice extracts correlated to the taxifolin content and antioxidant activity of the extracts. A new method for quantitative determination of taxifolin in superhongmi rice variety by high performance liquid chromatography was established. A reversed-phase system with Tosoh TSK-gel $C_{18}$ column using 60% methanol in water(pH 2.4) as a mobile phase was developed. Taxifolin was detected at 280 nm and the analysis was successfully carried out within 40 min. In ripening phase, the amount of taxifolin showed a mild decreasing slope. The highest contents was 59.27mg in 100g seed on the 30 days after heading(DAH). The optimum harvesting time, considering taxifolin content, maturity rate and thousand seed weight(TSW) was DAH 50. These results suggest that superhongmi rice which has high taxifolin content has the potential to contribute as a dietary supplement for controlling hyperglycemia and oxidative stress-linked diabetes complications.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.232-236
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• 2000

Multi-regression statistical analyses were applied for the water quality data of shallow alluvial ground water (n = 47) collected from the Youngdeok area, in order to quantitatively generalize the natural (non-anthropogenic) causes of regional water quality variation. Seven samples having the high contamination index ( $C_{a}$ > 3) reflect the striong effects by anthropogenic activity. Most of the alluvial groundwaters have acquired their quality primarily due to the dissolution of carbonate minerals. The results of multi-regression analysis show that chlorine is mainly derived from seawater effect. Sulfur isotopic compositions of dissolved sulfur and the S $O_4$/Cl ratio also enable us to discriminate the samples (n = 18) which are affected by atmospheric input of marine aerosol (sea-spray) and also by mixing between freshwater and seawater. Hydrogen and oxygen isotope data of the samples collected lie close to the local meteoric water line obtained from nearby Pohang city but has lower slope (5.45) on the $\delta$D-$^{18}$ O plot, indicating that alluvial groundwater was recharged from infiltrated meteoric water which has undergone some degree of kinetic evaporation. The estimated initial isotopic composition of the recharged water ($\delta$D = -74.8$^{0}$ /$_{00}$, $\delta$$^{18}$ O = -10.8$^{[-1000]}$ /$_{[-1000]}$ ) suggests that the alluvial ground water recharge largely occurs during summer storm events.s.s.

• Ocean Science Journal
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• v.40 no.2
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• pp.67-78
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• 2005

Complex physical, chemical and biological interactions off the Korean coast created several striking patterns in the phytoplankton blooms, which became conspicuous during the measurements of ocean color from space. This study concentrated on analyzing the spatial and temporal aspects of phytoplankton chlorophyll variability in these areas using an integrated dataset from a Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Advanced Very High Resolution (AVHRR) sensor, and Conductivity Temperature Depth (CTD) sensor. The results showed that chlorophyll concentrations were elevated in coastal and open ocean regions, with strong summer and fall blooms, which appeared to spread out in most of the enclosed bays and neighboring waters due to certain oceanographic processes. The chlorophyll concentration was observed to range between 3 and $54\;mg\;m^{-3}$ inside Jin-hae Bay and adjacent coastal bays and 0.5 and $8\;mg\;m^{-3}$ in the southeast sea offshore waters, this gradual decrease towards oceanic waters suggested physical transports of phytoplankton blooms from the shallow shelves to slope waters through the influence of the Tsushima Warm Current (TWC) along the Tsushima Strait. Horizontal distribution of potential temperature $(\theta)$ and salinity (S) of water off the southeastern coast exhibited cold and low saline surface water $(\theta and warm and high saline subsurface water $({\theta}>12^{\circ}C; S>34.4)$ at 75dBar, corroborating TWC intrusion along the Tsushima Strait. An eastward branch of this current was called the East Korean Warm Current (EKWC), tracked with the help of CTD data and satellite-derived sea surface temperature, which often influenced the dynamics of mesoscale anticyclonic eddy fields off the Korean east coast during the summer season. The process of such mesoscale anticyclonic eddy features might have produced interior upwelling that could have shoaled and steepened the nutricline, enhancing phytoplankton population by advection or diffusion of nutrients in the vicinity of Ulleungdo in the East Sea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.1
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• pp.18-23
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• 2004

This study was conducted to provide a national forest management method for natural Pinus densiflora forest stands in central South Korea based on growth characteristics and water relations. Average stand volume per hectare was 259.3㎥ in the pine study site. Basal area, volume, annual mean increment and periodic annual increment of DBH for 10 years at each slope aspect appeared to decrease as the aspect shifts from north to south. Stems per hectare showed the lowest value at the northern aspect. Maximum water potentials measured between 12 and 14 o'clock were analyzed by aspect and elevation. Water potential of pine decreased as the aspect changed from north to south, and water potential increased at lower elevations. Soil water content for the pine stands tended to decrease as the aspect shifted from north to south. Water potential and soil moisture content were highly correlated. Soil water deficits indicate that pines have a higher moisture requirement on the ridge and the southern aspect.