• Journal of the Korean Geographical Society
• /
• 제40권3호
• /
• pp.285-295
• /
• 2005

This paper was examined distribution and changing trends on occurrence days of Spring Cold(cold surge in the flowering season) from the end of February to early in April during 1973-2004. We defined an occurrence day of Spring Colds as above $10\%$ of the anomalies of mean daily temperature or above $10\%$ of the difference of the daily mean temperature between the day before two days. In the west coastal region, the occurrence days of Spring Colds is higher in the end of February and less frequent in the early in April. In the east coastal region, the occurrence days of Spring Colds is higher in the early in April. Spring Colds is closely related with frequencies and a intensities of Siberian High. The occurrence days of Spring Colds has decreased in the most area except Ulleung island and the east coastal region.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
• /
• pp.210-221
• /
• 1998

In the period from the year 1500 to 1980. at least 14 large earthquake with epicenters in the northeastern China and Yellow Sea were felt or destructive in the Korean Peninsula. The most sigmificant events among them were the 1668 July 25 Tancheng earthquake of mamnitude 8.5, and the 1975 Feb. 4 Haicheng earthquake of magnitude 7.3. The Haicheng earthquake of the year 1975 in am extraordinary one among those occurred in the northeastern China in the 20th century in the sense the Shake of the event affected all over the Korean Peninsula. The tremor was felt even at the southeastern tip of the Korea and northern part of Kyushu 700km far away from the epicenter. In order to see the variation and trend of the effect of the Haicheng earthquake on the Korean Peninsula, the two data sets of the northern and southern parts of the peninsula were merged into one combined data set. The spatial variation of intensity shows smooth decrease from the value 4 of the northwestern region near the source to the value 1 of the Cheju Island and Kjushu. However, there are four regions of locally high intensity value. They are the region along downstream of Abrok(Yalu) River with intensity 5, the region around Shinpo of intensity 4, the area comprising Seoul and Chuncheon Cities of intensity 4, and Pohang-Pusan area of intensity 3. We suppose that there might be three types of possible mechanisms. The first one is concerned with the lateral inhomogeneity of velocity in the crust caused by wide distribution of relatively fractured rock. The second one is related with reflections of surface waves caused by the crestal thinning effect at border regions of the Peninsular in contact with the Ulleung Basin and the Japan Basin. The third possibility is local site effect caused by thick Tertiary or Quaternary rocks and soil layers.

• Korean Journal of Plant Taxonomy
• /
• 제40권3호
• /
• pp.186-191
• /
• 2010

Four unrecorded species (Barbella flagellifera, Isothecium hakkodense, Mnium orientale and Fissidens gardneri) and with one unrecorded genus, Barbella, are reported new to the Korean moss flora. B. flagellifera (Meteoriaceae) was found on a tree at alt. 300-350 m of parasitic Seogeomun-oreum Volcano on Jeju Island. The species are mainly distributed in subtropic regions. I. hakkodense (Lembophyllaceae) was found around the top of Seongin-bong on Ulleung Island. This species is similar to I. subdiversiforme, however, it can be distinguished by the morphologies of branch leaves and alar cells. M. orientale (Mniaceae) was collected from Mt. Jiri. This is similar to M. heterophyllum, however, it can be distinguished by plant size, number of teeth in leaf margin and cell size on leaf. F. gardneri (Fissidentaceae) was found along the valley of Mt. Palyeong, Jeollanam Province. This species is similar to F. obscurirete, but distinguished by the size of the plants and their leaves as well as the costal lengths of the leaves.

• Journal of Navigation and Port Research
• /
• 제26권5호
• /
• pp.511-516
• /
• 2002

Cultural Property Preservation Bureau of Korea excavated the massive shipwreck and her cargo from 1976 to 1984 sunken under Jeungdo Island, Sinan County located in the southwest area of the Korean peninsula. It was the first systematic underwater excavation in Korea, and one of the richest underwater discovery in the world. According to the reference materials, more treasure shipwrecks are assumed to be sunk under seaside of Korean peninsula. Such as, Donskoy near Ulleung Island, Kow Shing near Ul Island, and Yamashita treasure ship off Korean peninsula, etc. The excavations of these treasure ship are likely to raise ownership dispute between private finders and government authority, and between ship owner and excavater due to lack of knowledge and awareness of related laws and regulations. Therefore, this study aims to examine existing legal regimes related to the excavated treasureship. And also it tries to suggest a new proactive measure to prevent the most likely ownership disputes between interested parties.

• Mycobiology
• /
• 제48권5호
• /
• pp.351-363
• /
• 2020

Here, we investigated fungal microbiota in the understory root layer of representative well-conserved geographically segregated natural wetlands in the Korean Peninsula. We obtained 574,143 quality fungal sequences in total from soil samples in three wetlands, which were classified into 563 operational taxonomic units (OTU), 5 phyla, 84 genera. Soil texture, total nitrogen, organic carbon, pH, and electrical conductivity of soil were variable between geographical sites. We found significant differences in fungal phyla distribution and ratio, as well as genera variation and richness between the wetlands. Diversity was greater in the Jangdo islands wetland than in the other sites (Chao richness/Shannon/Simpson's for wetland of the Jangdo islands: 283/6.45/0.97 > wetland of the Mt. Gariwang primeval forest: 169/1.17/0.22 > wetland of the Hanbando geology: 145/4.85/0.91), and this variance corresponded to the confirmed number of fungal genera or OTUs (wetlands of Jangdo islands: 42/283> of Mt. Gariwang primeval forest: 32/169> of the Hanbando geology: 25/145). To assess the uniqueness of the understory root layer fungus taxa, we analyzed fungal genera distribution. We found that the percentage of fungal genera common to two or three wetland sites was relatively low at 32.3%, while fungal genera unique to each wetland site was 67.7% of the total number of identified fungal species. The Jangdo island wetland had higher fungal diversity than did the other sites and showed the highest level of uniqueness among fungal genera (Is. Jangdo wetland: 34.5% > wetland of Mt. Gariwang primeval forest: 28.6% > wetland of the Hanbando geology: 16.7%).

• Journal of agriculture & life science
• /
• 제44권5호
• /
• pp.15-22
• /
• 2010

Vegetation structure and soil condition were analyzed to provide information for effective management of Acer okamotoanum community. Importance value of A. okamotoanum in upper layer was highest as 120.7, and that of Camellia japonica in middle and lower layer was highest as 61.8 and 15.7, while those of A. okamotoanum were 37.5 and 2.6, respectively. Taxus cuspidata var. latifolia which was designated as vulnerable species by Korea National Arboretum began its existence in lower layer. Species diversity and evenness were 0.674 and 0.706 in upper layer, 0.947 and 0.805 in middle layer, and 1.312 and 0.938 in lower layer, respectively. Soil pH of A. okamotoanum community was 5.79. The contents of organic matter, total N, and available $P_2O_5$ were 7.2%, 0.33%, and 51.1ppm, respectively.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 한국자원식물학회 2019년도 추계학술대회
• /
• pp.25-25
• /
• 2019

Chromosome numbers and karyotypes in flowering plants have been considered to be prominent features in taxonomic and evolutionary context. Despite the increasing numbers of cytological studies in Asteraceae, karyotype analysis of Cirsium Mill. and Carddus L. in Korean population have not been performed carefully. In this study, the chromosome numbers and karyotype analysis of all eight species of the genus Cirsium Mill. and one species of Carddus L. were analyzed. While the chromosome number in Carduus crispus L. was diploid (2n = 2x = 18 or 18+2Bs) with x = 9 as the base chromosome number, all seven species of Cirsium were diploid with x = 17 except for Cirsium lineare (Thunb.) Sch. Bip. (x = 14). The chromosome number in C. pendulum Fisch. ex DC. presented 2n = 2x = 34 from two populations and C. lineare exhibited 2n = 2x = 28 from one population. Aneuploidy was occasionally found in C. japonicum Fisch. ex DC. var. spinossinum Kitam. (2n = 2x = 34, 35, 36), C. rhinoceros (H. $L{\acute{e}}v.$ & Vaniot) Nakai (2n = 2x = 32, 34), C. setidens (Dunn) Nakai (2n = 2x = 30, 31, 32) and C. vlassovianum Fisch. ex DC. (2n = 2x = 31, 32). While Cirsium japonicum Fisch. ex DC. var. japonicum possessed several B-chromosomes (2n = 2x = 34, 35, 36), polyploidy was only encountered in Cirsium nipponicum (Maxim.) Makino. (2n = 4x = 68) from two populations in Ulleung Island. The present cytological data might be contributed to the taxonomic and evolutionary studies in the genus Cirsium.

• Journal of Navigation and Port Research
• /
• 제43권2호
• /
• pp.79-85
• /
• 2019

Climate change is a very vital issue that can be no longer avoided. Korea has been a top-level country Iin dealing with carbon dioxide emissions since 1960. Many studies have been conducted to suppress or eliminate carbon dioxide emissions, which account for a large portion of greenhouse gases. Carbon Capture and Storage (CCS), the most practical method of them, plays a significant role. However, these methods have the disadvantage of the limits of geographical distribution and high possibility of re-emission into the atmosphere. Recently, ocean storage has been studied using Accelerated Weathering of Limestone (AWL), a technique for storing carbon dioxide in the ocean as an alternative to CCS, an underground storage. AWL is a method of converting carbon dioxide into concentrated water in the form of bicarbonate ion and discharging it to the ocean to dilute and store it. It does not cause re-emission to the atmosphere, and the discharged concentrated water increases the alkalinity of the ocean to prevent marine acidification. The objective of this study was to understand the behavior of DIC (Dissolved Inorganic Carbon) including carbon dioxide during the ocean discharge of bicarbonate ion concentrated water in AWL method. This study area was set near Ulleung-do where sufficient water depth and operational efficiency were secured. CORMIX model was used to calculate the material diffusion by submerged discharge using ship.

• Journal of the Korea Organic Resources Recycling Association
• /
• 제26권4호
• /
• pp.5-10
• /
• 2018

In this study, the effect of physico-chemical factors (e.g., pressure, electrolyte, and organic matter) in the gas hydrate deposit on CH4-CO2 replacement process was investigated experimentally. The higher initial pressure during gas injection led the higher reaction rate at the first time, but finally it did not. Electrolytes and organic matter have some effects on reforming process after dissociation of gas hydrate. It is expected that further research using real marine sediments with actual gas hydrate will enable the development of technologies applicable to the characteristics of domestic seabed geology. Ultimately, it is expected that it will be possible to recover and utilize methane as an organic resource through application of domestic gas hydrate deposit in the Ulleung Basin, East Sea.

• Korean Journal of Medicinal Crop Science
• /
• 제27권3호
• /
• pp.194-201
• /
• 2019

Background: The Ministry of Environment, Korea recognizes Cotoneaster wilsonii Nakai as a second-class endangered plant. It is a native species that grows in Ulleung-do, Korea. To our knowledge, the bioactivity of this plant has not yet been reported. Therefore, in this study, we have reported the bioactivity of C. wilsonii Nakai. Methods and Results: The anti-oxidant activities of C. wilsonii methanolic extract were investigated in vitro. The anti-oxidant activity was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay, and the total phenolic and flavonoid content were measured. The leaf methanolic extract had the highest DPPH radical scavenging activity ($IC_{50}$; $15.74{\mu}g/m{\ell}$), and it also had the highest total phenolic and flavonoid content ($220.95mg{\cdot}GAE/g$, and $36.46mg{\cdot}QE/g$ extract respectively). Through high performance liquid chromatography (HPLC) analysis, chlorogenic acid was found to be the predominant among all phenolic compounds, showing a concentration of 84.24 mg/g extract. More than 60% decrease in nitric oxide (NO) production was found in the leaf methanolic extract. Conclusions: To the best of our knowldege, this is the first report of the bioactivities of C. wilsonii. The results demonstrate that the leaf methanolic extract of C. wilsonii shows potent anti-oxidant, and anti-inflammatory activities.