• Journal of the Korean Geotechnical Society
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• v.23 no.3
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• pp.111-121
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• 2007

The paper presents a reliability-based method that can capture the impact of uncertainty of seismic loadings. The proposed method incorporates probabilistic concepts into the classical limit equilibrium and the Newmark-type deformation techniques. The risk of damage is then computed by Monte Carlo simulation. Random process and RMS hazard method are introduced to produce seismic motions and also to use them in the seismic slope analyses. The geotechnical variability and sampling errors are also considered. The results of reliability analyses indicate that in a highly seismically active region, characterization of earthquake hazard is the more critical factor, and characterization of soil properties has a relatively small effect on the computed risk of slope failure and excessive slope deformations. The results can be applicable to both circular and non-circular slip surface failure modes.

• Applied Microscopy
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• v.46 no.2
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• pp.83-88
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• 2016

Structural differentiation of the connective stalk in giant duckweed, Spirodela polyrhiza, was examined to reveal the anatomical and ultrastructural characteristics within reduced shoot. The study focuses primarily on structural features of the connective stalk (CT), which connect offspring to their mother fronds. Photoautotrophic offspring fronds remained connected by stalks to mother fronds in the reproductive pockets until separation. The CT originated from the meristematic region of the abaxial frond and joined the fronds laterally with two abscission layers. The most notable features of the CT were polymorphic mitochondria, random occurrences of fibrillar structures in intercellular spaces, and great variability in cell wall thickness. Vascular tissues in CTs were highly reduced, demonstrating only a central vascular strand. Grana with 2 to 4 thylakoids and starch grains were found in the chloroplasts. A chlorophyll assay indicated high chlorophyll concentrations in daughter fronds and low concentrations in CTs. The frond and CT, while physically connected to each other, functioned independently. Despite great reduction in S. polyrhiza, the CT has proven to be very efficient for separating offspring from the mother frond, which lends to its capacity for rapid vegetative reproduction. The ultrastructural aspects of CTs in S. polyrhiza were characterized for the first time in this study.

• Atmosphere
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• v.28 no.2
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• pp.153-162
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• 2018

The statistical prediction model for wintertime surface air temperature, that is based on snow cover extent and Arctic sea ice concentration, is updated by considering $El-Ni{\tilde{n}}o$ Southern Oscillation (ENSO) and Quasi-Biennial Oscillation (QBO). These additional factors, representing leading modes of interannual variability in the troposphere and stratosphere, enhance the seasonal prediction over the Northern Hemispheric surface air temperature, even though their impacts are dependent on the predicted month and region. In particular, the prediction of Korean surface air temperature in midwinter is substantially improved. In December, ENSO improved about 10% of prediction skill compared without it. In January, ENSO and QBO jointly helped to enhance prediction skill up to 36%. These results suggest that wintertime surface air temperature in Korea can be better predicted by considering not only high-latitude surface conditions (i.e., Eurasian snow cover extent and Arctic sea ice concentration) but also equatorial sea surface temperature and stratospheric circulation.

• Journal of the Korean Wood Science and Technology
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• v.33 no.1 s.129
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• pp.21-28
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• 2005

Tracheid length and width, microfibril angle, compressive, bending, and impact strengths between the south and north sides of stem pith in Larix kaemferi were measured. Sample trees were 30 years old which had planted in the central region of Korea. In general, there were no difference in the tracheid length and width, microfibril angle, and strengths between the two sides. And no difference in tangential shrinkage and strengths between the two sides was thought to be due to identical microfibril angle between the two sides.

• Journal of the Korean earth science society
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• v.34 no.1
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• pp.102-106
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• 2013

The intensity of the East Asian summer monsoon has a negative correlation with that of the western North Pacific summer monsoon. Based on the relationship, we suggest the potential predictability of Northeast Asian summer precipitation by using the relationship. The western North Pacific subtropical high (WNPSH) properly represents the intensity of the western North Pacific summer monsoon. It also dominates climate anomalies in the western North Pacific-East Asian region in summertime. The estimates of the Northeast Asian summer rainfall anomalies using WNPSH variability have a greater benefit than those using the western North Pacific monsoon index.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.44.2-44.2
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• 2017

We obtained near-infrared spectra of 26 SDSS quasars at 0.7${\sim}10^{{\wedge}{10}}M{\odot}$ to critically examine the systematic effects involved with their mass estimations. We find that active galactic nuclei (AGNs) heavier than $10^{{\wedge}{10}}M{\odot}$ often display double-peaked $H{\alpha}$ emission, extremely broad FeII complex emission around MgII, and highly blueshifted and broadened CIV emission. The weight of this evidence, combined with previous studies, cautions against the use of MBH values based on any emission line with a width over 8000 km/s. Also, the MBH estimations are not positively biased along the presence of ionized narrow line outflows, anisotropic radiation, or the use of line FWHM instead of ${\sigma}$ for our sample, and unbiased with variability, scatter in broad line equivalent width, or obscuration for general type-1 quasars. Removing the systematically uncertain MBH values, ${\sim}10^{{\wedge}{10}}M{\odot}$ BHs in 1${\sim}10^{{\wedge}{9.5}}M{\odot}$ BHs, although current observations support they are intrinsically most massive, and overmassive to the host's bulge mass.

• Atmosphere
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• v.30 no.3
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• pp.311-318
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• 2020

Impacts on the atmospheric circulation and ocean system over the Mediterranean during boreal summer are investigated using Coupled Model Intercomparison Project Phase 5 (CMIP5) historical simulations (from 1911 to 2005). As the climate warms, global and remote effects lead to a strengthening in descending motion, an increase in sea surface temperature (SST) and surface dryness, but a decrease in marine primary production over the Western Mediterranean. The global effect is estimated from interannual variability over the global mean SST and the remote effect is driven by diabatic forcing generated from the South and East Asian summer monsoons. On the other hand, a local contribution leads to the strengthened descending motion and increased surface dryness over the Eastern Mediterranean, whereas the marine primary production over this region tends to increase due to possibly the urban wastewater and sewage. Our result suggests that particular attention needs to be paid to conserve the marine ecosystem over the Mediterranean.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.453-458
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• 2001

The Rural Development Administration (RDA) of Korea now operates a system called Rice Variety Selection Tests (RVST), which are now being implemented in eight Agricultural Research and Extension Services located in eight province RVST's objective is to provide accurate yield estimates and to select well-adapted varieties to each province. Systematic evaluation of entries included in RVST is a highly important task to select the best-adapted varieties to specific location and to observe the performance of entries across a wide range of test sites within a region. The rice yield data in RVST for ordinary transplanting in Kangwon province during 1997-2000 were analyzed. The experiments were carried out in three replications of a random complete block design with eleven entries across five locations. Additive Main effects and Multiplicative Interaction (AMMI) model was employed to examine the interaction between genotype and environment (G$\times$E) in the biplot form. It was found that genotype variability was as high as 66％, followed by G$\times$E interaction variability, 21％, and variability by environment, 13％. G$\times$E interaction was partitioned into two significant (P＜0.05) principal components. Pattern analysis was used for interpretation on G$\times$E interaction and adaptibility. Major determinants among the meteorological factors on G$\times$E matrix were canopy minimum temperature, minimum relative humidity, sunshine hours, precipitation and mean cloud amount. Odaebyeo, Obongbyeo and Jinbubyeo were relatively stable varieties in all the regions. Furthermore, the most adapted varieties in each region, in terms of productivity, were evaluated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.1
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• pp.49-63
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• 2016

In this study, we analyzed the effects of regional hydrologic variability during warm season (June-September) in South Korea due to ENSO (El $Ni{\tilde{n}}o$-Southern Oscillation) pattern changes over the Tropical Pacific Ocean (TPO). We performed composite analysis (CA) and statistical significance test by Student's t-test using observed hydrologic data (such as, precipitation and streamflow) in the 113 sub-watershed areas over the 5-Major River basin, in South Korea. As a result of this study, during the warm-pool (WP) El $Ni{\tilde{n}}o$ year shows a significant increasing tendency than normal years. Particularly, during the cold-tongue (CT) El $Ni{\tilde{n}}o$ decaying years clearly decreasing tendency compared to the normal years was appeared. In addition, the La $Ni{\tilde{n}}a$ years tended to show a slightly increasing tendency and maintain the average year state. In addition, from the result of scatter plot of the percentage anomaly of hydrologic variables during warm season, it is possible to identify the linear increasing tendency. Also the center of the scatter plot shows during the WP El $Ni{\tilde{n}}o$ year (+17.93%, +26.99%), the CT El $Ni{\tilde{n}}a$ year (-8.20%, -15.73%), and the La $Ni{\tilde{n}}a$ year (+8.89%, +15.85%), respectively. This result shows a methodology of the tele-connection based long-range water resources prediction for reducing climate forecasting uncertainty, when occurs the abnormal SSTA (such as, El $Ni{\tilde{n}}o$ and La $Ni{\tilde{n}}a$) phenomenon in the TPO region. Furthermore, it can be a useful data for water managers and end-users to support long-range water-related policy making.

• Journal of fish pathology
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• v.17 no.3
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• pp.159-169
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• 2004

Bacterial wihte enteritis ocurred by infection of V. ichthyoenteri is a devastating disease in olive flounder (Paralichthys olivaceus) hatcheries in Korea. Since white enteritis has been a problem in aquqtic industries, necessity of a rapid detection method is increased. In an attempt to develop rapid PCR method the detection of V. ichthyoenteri, we examined the 16S-23S rRNA intergenic spacer region(ISR) of V. ichthyoenteri and developed species-specific primer for V. ichthyoenteri. The intergenic spacers were amplified by primers complementary to conserved region of 16S and 23S rRNA genes. The intergenic spacer region between the 16S and 23S rRNA genes of V. ichthoenteri were investigated by PCR fragment length typing and DNA sequencing. Analysis of the ISR sequences showed that V. ichthyoenteri contains one types of polymorphic ISRs. The size of ISRs ranged 348bp length and not contains tRNA genes. Mutiple alignment of representative sequences from different Vibrio species revealed several domains of high sequence variability, and allowed to design species-specific primer for detection of Vibrio ichthyoenteri. PCR. The specific of the primer was examined using genomic DNA prepared from 19 different Vibrio species, isolated 18group Vibrio species. The results showed that the PCR reaction using species-specific primer designed in this study can be used to detect V. ichthyoenteri.