• Journal of the Korean Electrochemical Society
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• v.24 no.3
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• pp.52-64
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• 2021

The effect of Fe and BO₃ doping on structure, thermal, and electrical properties of Li_1+xFe_xTi_2-x(PO₄)_3-y(BO₃)_y (x = 0.2, 0.5)-based glass and glass ceramics was investigated. In addition, their crystallization behavior during sintering and ionic conductivity were also investigated in terms of sintering temperature. FT-IR and XPS results indicated that Fe²⁺ and Fe³⁺ ions in Li_1+xFe_xTi_2-x(PO₄)_3-y(BO₃)_y glass worked as a network modifier (FeO₆ octahedra) and also as a network former (FeO₄ tetrahedra). In the case of the glass with low substitution of BO₃, boron formed (PB)O₄ network structure, while boron preferred BO₃ triangles or B₃O₃ boroxol rings with increasing the BO₃ content owing to boic oxide anomaly, which can result in an increased non-bridging oxygen. The glass transition temperature (GTT) and crystallization temperature (CT) was lowered as the BO₃ substitution was increased, while Fe²⁺ lowered the GTT and raised the CT. The ionic conductivity of Li_1+xFe_xTi_2-x(PO₄)_3-y(BO₃)_y glass ceramics were 8.85×10^-4 and 1.38×10^-4S/cm for x = 0.2 and 0.5, respectively. The oxidation state of doped Fe and boric oxide anomaly were due to the enhanced lithium ion conductivity of glass ceramics.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.130-138
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• 2011

This study was carried out to investigate growth characteristics and propagation methods of Clerodendron trichotomum for landscape uses. The results are obtained as follows: In the first place, Korean native C. trichotomum was printed in the "Enumeration of plants in Chosun" in 1937 by Tae Hyun Chung. C. trichotomum is a shrub with round shape. This is noted for its late summer flowers, showy fruit and malodorous foliage. White flowers in long-peduncled cymes bloom in the upper leaf axils from late summer into fall. Flowers are followed by small bright blue fruits, each subtended by a fleshy red calyx. C. trichotomum showed high seed germination rate and greater shoot length in plug box than in normal seeding bed. The rooting rate of C. trichotomum according to cutting date was highest on July 7. The optimum date for cutting was on July 7~10 when the shoots were more hardened. Soil acidity ranged from pH 4.58 to 5.52. The most effective method for rooting of C. trichotomum was treatment with 1,000 ppm IBA on July 7 cuttings, which showed rooting rate of over 90%. Korean native C. trichotomum was successfully propagated through soft cutting and seed.

• (The)Study of the Eastern Classic
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• no.72
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• pp.299-327
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• 2018

The objective of this study is to examine the regional distribution of Ssireum(Traditional Wrestling) of South and North Korea in the Japanese colonial era. The conclusions of this study are as follows. First, the "Joseon ui hyangto orak(Folk play in Joseon)" showed the record of performing 272 times of Ssireum in 226 regions of the whole nation. Second, the Ssireum of South Korea could be divided into five regions. Seoul/Gyeonggi-do performed Ssireum the most in Dano, Baekjung, and Chuseok while Chungcheong-do performed Ssireum in Baekjung and Chuseok. Jeolla-do and Gyeongsang-do performed Ssireum in Chuseok while Gangwon-do performed Ssireum in Dano and Chuseok. Third, the Ssireum of North Korea could be divided into three regions. All the Hwanghae-do, Pyeongan-do, and Hamgyeong-do performed Ssireum the most in Dano. Fourth, as the period when Ssireum was held the most in the whole nation, Dano, Baekjung, and Chuseok could be pointed out. Ssireum has the characteristics of large-scale play between village communities or regions, instead of individual game. Thus, the Ssireum that was played as a sport event under certain rules for a long time was settled down as a folk play of regional festivals such as Dano, Baekjung, and Chuseok. Fifth, as a folk play and a representative play of seasonal customs, Ssireum was distributed in the whole nation and handed down till today under the regional deviation of South and North Korea. Sixth, the unidentified regions of South Korea that did not perform Ssireum were six places including five dos such as Gapyeong Gyeonggi-do, Boseong Jeollanam-do, Jeju-do, Gunwi and Cheongsong Gyeongsanbuk-do, and Inje Gangwon-do. The regions of North Korea were six places including three dos such as Pyeongyang, Yangdeok, Gangdong, and Gaecheon of Pyeongannam-do, Bakcheon Pyeonganbuk-do, and Dancheon Hamgyeongnam-do. Total 12 places in eight regions were included. Seventh, the number of total items of play names presented in the "Joseon ui hyangto orak(Folk play in Joseon)" was about 6,400 types. Out of them, about 1,300 types were the items including how to play while about 5,100 types were the items presenting the play names only without explanations. Especially, in case of Ssireum, the periods of the lunar calendar were only specified in each region. Unfortunately, it was not possible to check the contents about the actual performance methods and types of Ssireum as they were omitted.

• Journal of the Korean earth science society
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• v.42 no.6
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• pp.632-645
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• 2021

Satellite sea surface temperature (SST) composites provide important data for numerical forecasting models and for research on global warming and climate change. In this study, six types of representative SST composite database were collected from 2007 to 2018 and the characteristics of spatial structures of SSTs were analyzed in seas around the Korean Peninsula. The SST composite data were compared with time series of in-situ measurements from ocean meteorological buoys of the Korea Meteorological Administration by analyzing the maximum value of the errors and its occurrence time at each buoy station. High differences between the SST data and in-situ measurements were detected in the western coastal stations, in particular Deokjeokdo and Chilbaldo, with a dominant annual or semi-annual cycle. In Pohang buoy, a high SST difference was observed in the summer of 2013, when cold water appeared in the surface layer due to strong upwelling. As a result of spectrum analysis of the time series SST data, daily satellite SSTs showed similar spectral energy from in-situ measurements at periods longer than one month approximately. On the other hand, the difference of spectral energy between the satellite SSTs and in-situ temperature tended to magnify as the temporal frequency increased. This suggests a possibility that satellite SST composite data may not adequately express the temporal variability of SST in the near-coastal area. The fronts from satellite SST images revealed the differences among the SST databases in terms of spatial structure and magnitude of the oceanic fronts. The spatial scale expressed by the SST composite field was investigated through spatial spectral analysis. As a result, the high-resolution SST composite images expressed the spatial structures of mesoscale ocean phenomena better than other low-resolution SST images. Therefore, in order to express the actual mesoscale ocean phenomenon in more detail, it is necessary to develop more advanced techniques for producing the SST composites.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.226-239
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• 2021

Sebastes minor, Sebastes trivittatus, Sebastes owstoni, and Sebastes steindachneri are indigenous fish species inhabiting the central part of the East Sea, Korea. In order to understand the molecular evolution of these four rockfishes, we sequenced the complete mitochondrial genomes (mitogenomes) of S. minor and S. trivittatus. To further analyze the phylogeny of Sebastes species, the mitogenomes of 16 rockfishes were comparatively investigated. The complete mitochondrial DNA (mtDNA) nucleotide sequences of S. minor and S. trivittatus were 16,408 bp and 16,409 bp in length, respectively. A total of 37 genes were found in mtDNA of S. minor and S. trivittatus, including 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, which exhibited similar characters with other Sebastes species in the East Sea, Korea. In addition, we detected a conserved motif "ATGTA" in the control region of the four Sebastes species, but no tandem repeat units. Comparative analyses of the congeneric mitochondrial genomes were performed, which showed that control regions were more variable than the concatenated protein-coding genes. As a result of analysing phylogenetic relationships of four Sebastes species by using concatenated nucleotide sequences of 13 protein-coding genes, S. minor, S. trivittatus, S. owstoni and S. steindachneri were clustered into three clades. The phylogenetic tree exhibited that S. minor and S. steindachneri shared a closer relationship, whereas S. trivittatus and S. vulpes formed another distinct clade. Our results contribute to a better understanding of evolutionary patterns of Sebastes species inhabiting the middle East Sea, Korea.

• Journal of Marine Life Science
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• v.8 no.1
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• pp.8-31
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• 2023

To understand the distribution and formation mechanism of benthic foraminiferal assemblages, grain size analysis, ¹⁴C radiocarbon dating, and benthic foraminifera analysis were conducted on thirty-two surface sediments collected from the continental shelf of the northern East China Sea, respectively. Surface sediment was composed of sandy mud~muddy sand facies with an average of 52.04% of sand, 13.72% of silt, and 34.20% of clay. These sedimentary facies are palimpsest sediment. Benthic foraminifera was classified into a total of 48 genera and 104 species, including agglutinated foraminifera, calcareous-hyaline, and calcareous-porcelaneous foraminifera. The production rate of agglutinated foraminifera increased toward the Yangtze River area while that of planktonic foraminifera increased toward Jeju Island. Dominant species are Ammonia ketienziensis, Bolivina robusta, Eggella advena, Eilohedra nipponica, Pseudorotalia gamardii, Pseudoparrella naraensis. ¹⁴C radiocarbon datings of Bolivina robusta and Pseudorotalia gamardii with the highest production rate were 2,360±40 yr B.P. and 2,450±40 yr B.P., respectively. In the result of cluster analysis, three assemblages composed of P. gaimardii, B. robusta, and A. ketienziensis-P. naraensis were classified broadly. P. gaimardii assemblage is thought to be formed from about 2.5 yr B.P. at the sea area of the Yangtze River to 50 m in water depth affected by fresh water. B. robusta assemblage is thought to be formed from about 2.4 yr B.P. at the sea area of Jeju Island to 50~100 m affected by offshore water. And then, A. ketienziensisP. naraensis assemblage was formed in the northwest sea area (Central Yellow Sea Mud). These distributions and composition of benthic foraminiferal assemblages formed from about 2.5 yr B.P. in the northern East China Sea are thought to be due to the change of benthic ecology environment that occurred by the sea level increase during the late Holocene.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.1
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• pp.59-70
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• 2024

As urbanization progresses, the demand for parks and green space is increasing. Park green spaces in the city are important spaces in the city because they are recognized as spaces where people can freely engage in outdoor activities. The park service area is a measure that shows the extent to which services are provided based on distance. In this process, the concept of accessibility plays an important role, and walking, in particular, as the most basic means of transportation for people and has a great influence on the use of parks. However, the current park service area analysis focuses on discovering underprivileged areas, so detailed evaluation of beneficiary areas is insufficient. This study seeks to evaluate park service areas based on the pedestrian accessibility and the pedestrian network. Park services are services that occur when users directly visit the park, and accessibility is expected to be reflected in terms of usability. To quantify the pedestrian network, this study used space syntax to analyze pedestrian accessibility based on integration values. The integration values are an indicators that quantify the level of accessibility of the pedestrian network, and in this study, the higher the integration value, the higher the possibility of park use. The results of the study are as follows. First, Bundang-gu's park service area accounts for 43%, and includes most sections with high pedestrian accessibility, but some sections with good pedestrian accessibility are excluded. This can be seen as a phenomenon that occurs when residential areas and commercial and business areas are given priority during the urban planning process, and then park and green areas are selected. Second, based on Bundang-gu, the park service area and pedestrian accessibility within the park service area were classified by neighborhood unit. Differences appear for each individual neighborhood unit, and it is expected that the availability of the park will vary accordingly. In addition, even in areas created during the same urban planning process, there were differences in the evaluation of park service areas according to pedestrian accessibility. Using this, it is possible to evaluate individual neighborhood units that can be reflected in living area plans, and it can be used as a useful indicator in park and green space policies that reflect this in the future.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.2
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• pp.69-79
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• 2009

Major and trace elements were analyzed in three core sediments to investigate geochemical characteristics of East Sea sediments and provenance changes during late Quaternary in Ulleung Basin. Comparing with Yellow and South Sea sediments, contents of major elements were generally similar while contents of trace elements were significantly different. Furthermore, within this basin, there were some variabilities in trace element compositions. In the western slope sediments (WS), Mo was enriched over 6 times as much as other sites. On the other hand, Zr, Nb, Hf and Ta were enriched in basin sediments (Basin), and Ca and Cs were enriched in southern slope sediments (SS). After excluding elements derived from biogenic, authigenic and diagenetic origins, the lithogenic elements (K, Ti, Cs, Zr, Nb, Hf and Ta) could be classified into three groups from the comparison of element/Al ratios among cores. The first group consisted of elements (K and Ti) that showed the nearly similar element/Al ratios among three cores. The second group contained Cs which showed significant difference between two slope sediments. The third group elements (Zr, Nb, Hf and Ta) showed highly enriched in basin relative to both slope areas. The depth profiles of metal/Al ratios in basin sediments provided the following interpretation for the compositions of sediment and their variation. From 10,000 yr B.P. to 7,000 yr B.P. two lithogenic components (volcanic ashes and western slope sediments) were mixed and deposited in the basin. After 7,000 yr B.P., however, southern slope sediments were mixed with volcanic ashes and deposited in basin area. This event of source change is nearly close to inflow period of the Tsushima Warm Current to Ulleung Basin. Thus, it might be suggested that element geochemistry in Ulleung basin sediment indicate the change of current system in the study area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.27-41
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• 2008

Distribution characteristics of phytoplankton community were investigated by HPLC and flow cytometry in Jeju Strait and the Northern East China Sea (NECS) in May 2004, in order to understand the relationship between physical environmental factors and distribution pattern of phytoplankton communities. Based on temperature and salinity data, three distinct water masses were identified; warm and saline Tsushima Warm Current (TWC), which is flowing from northwest of Jeju Island, warm and low saline water at the center of Jeju Strait, which is originated from China Coastal Water (CCW) and relatively cold and high saline water originated from Yellow Sea at the bottom of the Jeju Strait. At Jeju Strait, less saline water (<33 psu) of 15 km width occupied surface layer up to 20 m which located at 20 km offshore and strong thermal front between warm and saline water and cold and less saline water was found in the middle of the Jeju Strait. Vertical transect of temperature and salinity at the NECS also showed that low saline (<33 psu) water occupied the upper 20 m layer and cold and saline water was present at the eastern part. Chl a was measured as $0.06{\sim}3.07\;{\mu}g/L$. Spring bloom of phytoplankton was recognized by the high concentrations of Chl a at the low saline water masses influenced by the CCW and subsurface chlorophyll maximum layer appeared between $20{\sim}30\;m$ depth, which was at thermocline depth or below. Abundances of Synechococcus and picoeukaryote were $0.2{\sim}9.5{\times}10^4\;cells/mL$ and $0.43{\sim}4.3{\times}10^4\;cells/mL$, respectively. Dinoflagellate, diatom and prymnesiophyte were major groups and minor groups were chlorophyte+prasinophyte, chrysophyte, cryptophyte and cyanophyte. Especially high abundance of dinoflagellate was identified by high concentration (>1\;{\mu}g/L$) of peridinin at the bottom of the thermocline, which showed an outbreak of red tide by high density of dinoflagellates. Abundances of picoeukaryote in Jeju Strait were about $5{\sim}10$ times higher than abundance measured in Kuroshio water and showed a good correlation with Chl b (Pras+Viola), which implies the most of population of picoeukaryote was composed of prasinophytes. Prochlorococcus was not detected at all, which suggests that Kuroshio Current did not directly influenced on the study area. Based on the strong negative correlations between biomass of phytoplankton (Chl a) and temperature+salinity, the primary production and biomass of phytoplankton in the study area were controlled by the nutrients supply from CCW.

• Journal of the Korean earth science society
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• v.45 no.2
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• pp.136-146
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• 2024

This paper introduces the seismic facies classification and mapping of igneous bodies found in the sedimentary sequences of the Yellow Sea shelf area of Korea. In the research area, six extrusive and three intrusive types of igneous bodies were found in the Late Cretaceous, Eocene, Early Miocene, and Quaternary sedimentary sequences of the northeastern, southwestern and southeastern sags of the Gunsan Basin. Extrusive igneous bodies include the following six facies: (1) monogenetic volcano (E.mono) showing cone-shape external geometry with height less than 200 m, which may have originated from a single monogenetic eruption; (2) complex volcano (E.comp) marked by clustered monogenetic cones with height less than 500 m; (3) stratovolcano (E.strato) referring to internally stratified lofty volcanic edifices with height greater than 1 km and diameter more than 15 km; (4) fissure volcanics (E.fissure) marked by high-amplitude and discontinuous reflectors in association with normal faults that cut the acoustic basement; (5) maar-diatreme (E.maar) referring to gentle-sloped low-profile volcanic edifices with less than 2 km-wide vent-shape zones inside; and (6) hydrothermal vents (E.vent) marked by upright pipe-shape or funnel-shape structures disturbing sedimentary sequence with diameter less than 2 km. Intrusive igneous bodies include the following three facies: (1) dike and sill (I.dike/sill) showing variable horizontal, step-wise, or saucer-shaped intrusive geometries; (2) stock (I.stock) marked by pillar- or horn-shaped bodies with a kilometer-wide intrusion diameter; and (3) batholith and laccoliths (I.batho/lac) which refer to gigantic intrusive bodies that broadly deformed the overlying sedimentary sequence.