• Bulletin of the Korean Space Science Society
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• 2008.04a
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• pp.17.2-17.2
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• 2008

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1691-1707
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• 2022

Cheonji Lake, the caldera of Baekdu Mountain, located on the border of the Korean Peninsula and China, alternates between melting and freezing seasonally. There is a magma chamber beneath Cheonji, and variations in the magma chamber cause volcanic antecedents such as changes in the temperature and water pressure of hot spring water. Consequently, there is an abnormal region in Cheonji where ice melts quicker than in other areas, freezes late even during the freezing period, and has a high-temperature water surface. The abnormal area is a discharge region for hot spring water, and its ice gradient may be used to monitor volcanic activity. However, due to geographical, political and spatial issues, periodic observation of abnormal regions of Cheonji is limited. In this study, the degree of ice change in the optimal region was quantified using a Landsat -5/-7/-8 optical satellite image and a Modified U-Net regression model. From January 22, 1985 to December 8, 2020, the Visible and Near Infrared (VNIR) band of 83 Landsat images including anomalous regions was utilized. Using the relative spectral reflectance of water and ice in the VNIR band, unique data were generated for quantitative ice variability monitoring. To preserve as much information as possible from the visible and near-infrared bands, ice gradient was noticed by applying it to U-Net with two encoders, achieving good prediction accuracy with a Root Mean Square Error (RMSE) of 140 and a correlation value of 0.9968. Since the ice change value can be seen with high precision from Landsat images using Modified U-Net in the future may be utilized as one of the methods to monitor Baekdu Mountain's volcanic activity, and a more specific volcano monitoring system can be built.

• Journal of Gastric Cancer
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• v.2 no.1
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• pp.12-19
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• 2002

Purpose: The H. pylori cagA gene, vacA gene and iceA gene are considered to be important virurence factors that have been implicated in the development of gastric adenocarcinoma. It was reported that the presence of IS605 elements may be responsible for rearrangements and lead to partial or total deletions of the cag pathogenicity island (PAI) and the virulence of cag PAI may be changed. However, different results regarding the association between these virulence factors and clinical disease have been reported from different geographic regions. This study evaluated the relationship between H. pylori virulence factors such as cagA, vacA, iceA, IS605 and gastric adenocarcinoma. Materials and Methods: H. pylori isolates were obtained from 54 infected patients (24 cases of gastric adenocarcinoma, 30 cases of control). H. pylori isolates were identified by PCR with ureC gene and 16S rRNA. PCR was performed to examine cagA, vacA, iceA and IS605 genotypes. Results: Significant difference was found in the negative rates of cagA between gastric adenocarcinoma group and control ($62.5\%\;vs.\;33.3\%$ P=0.033). No significant difference was found in the prevalence of iceA, vacA between gastric adenocar cinoma and control. The genotype of cagA+ vacA s1-m1 iceA1 was predominant in H. pylori isolates irrespective of the clinical outcome. IS605 in PAI was not found in gastric adenocarcinoma gruop and control. The positive rates of IS605 in genome were $33.3\%$ in gastric adenocarcinoma group and $36.7\%$ in control (P>0.05). In gastric carcinoma, the positive rate of $cagA^{+}/IS605$ was lower than in control ($12.5\%\;vs\;40.0\%$, P=0.025) and the positive rate of cagA-/IS605 was higher than in control ($54.2\%\;vs\;23.3\%$, P=0.02). Conclusion: H. pylori virulence factors had not related significantly with gastric adenocarcinoma. Further study is needed to examine the specificity of H. pylori strains.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.69-70
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• 2013

IPCC (International Panel on Climate Change) reported that the arctic sea-ice extent has been decreased by 2.7% per decades since satellite observations in 1978. The decreased sea-ice extent has gained an international attention due to its economical benefits from the NSR (Northen Sea Route). The NRS - not a clearly defined single route, but a number of alternative routes across the top of Russiahas a 37 % reduction in sailing distance, comparing to the SSR (Southen Sea Route) passing thourgh the Suez Canal. Sailing days are consequently reduced from 30 days to 20 days. Also, it is estimated that the Northen Sea has 20 to 25% of world's oil resources and occupies 40% of the world's fishery production. As Republic of Korea was admitted as an observer to the Arctic Council on May 15, 2013, there has been increasing needs to explore new route in the Northen Sea. In this situation, Korea Institute of Ocean Science & Technology (KIOST) is preparing a plan for the development of Arctic-circle Ocean Environmental Information System to support the ice navigation and resource exploration in the Arctic. We will introduce a conceptual design of a satellite-based ice navigation supporting system for the northern sea route.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.21-27
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• 2019

R-404A, which is used widely in small-scale ice makers, is scheduled to be phased out because of its high global warming potential. In this study, drop-in tests were conducted using R-448A and R-449A, which replace R-404A, to modify the outdoor air and supply water temperatures. The results showed that the daily ice production rate of R-404A was 5.3% higher than that of R-448A and 4.2% higher than that of R-449A. This was attributed to the larger vapor density of R-404A, which resulted in a larger mass flow rate in the system. Between R-448A and R-449A, R-448A yielded a larger amount of ice at low air and water temperatures, whereas R-449A yielded a larger amount of ice at high air and water temperatures. The daily power consumption of R-404A was approximately 10% larger than those of R-448A and R-449A. The resulting COPs of R-448A and R-449A was similar, only 3.0% larger than that of R-404A. The literature survey showed that the condensation or evaporation data of R-448A or R-449A are very limited, and research on this issue is recommended.

• Journal of the Korean earth science society
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• v.42 no.6
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• pp.677-687
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• 2021

In this study, we analyzed diatoms from core RS15-GC41 collected in Iselin Bank, Ross Sea. A total of 24 genera and 35 species of diatoms are identified, and the having valve abundance of diatoms varies from 0.2 to 28.6×10⁶/g. Four diatom assemblage zones are established by the vertical distribution of diatoms, and changed with a cycle of 100 kyrs. RS15-GC41 were deposited over the last 400 kyrs (corresponding to Marine Isotope Stages 1-11). The open-water species Fragilariopsis kerguelensis, Rhizosolenia styliformis, and Thalassionema nitzschioides abundantly occurred in interglacial periods. Whereas, Actinocyclus actinochilus abundantly dominant during the glacial periods. The distribution of these diatoms indicated, it can be seen that the sea-ice extent was larger and lasted longer during MIS 7, 9, and 11 than that of MIS 1, 3, and 5. Moreover, Paralia sulcata was abundantly predominant in MIS 7, 9, and 11; this finding suggests likely indicating that P. sulcata was transported from the coastal/inner shelf area to the study site, during accumulated in the sediments, reworked with the influx of ice-rafted debris by the currents

• Korean Journal of Plant Resources
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• v.35 no.5
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• pp.652-658
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• 2022

This study was conducted to induce somatic embryogenic callus (SEC) derived from petals in rose. The petal explants of 3 cultivars ('Ice Wing', 'Orange Eye' and 'Pink Beauty') with different flower colors were placed on three types media (MS, SH and WPM) supplemented with 11 mg/L 2,4-D, respectively, and then cultured in the dark for 47 days. Calluses were formed at explants of all three cultivars. Also, 'Ice Wing', which were cultured in the SH as the basal medium, showed the highest callus formation rate. However, somatic embryos were generated from only petal-derived callus of 'Ice Wing', which were induced on the WPM as the basal medium, transferred it to SH basal medium supplemented with 3 mg/L 2,4-D, and 300 mg/L L-proline, and cultured for 5 weeks. The SEC has been proliferated every four weeks at the subculture interval. In addition, as a results of making a comparison of expression of RhSERK3 and RhSERK4, which is used as signal for generation of somatic embryo from callus in rose, between the SEC and petal-derived callus from 'Ice Wing' by RT-qPCR, the former showed 10 times higher RhSERK3 expression and 700 times higher RhSERK4 expression than the latter.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.183-188
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• 1978

In this study, gas chromatographic analysis was carried out on volatile constituents of cooked squid for the object of obtaining information on the characteristic flavor of the cooked squid meat. The results obtained are as follows: 1) Methanol was the most effective solvent for the extraction of volatile constituents of squid meat. 2) Twenty five and thirty two peaks were detected from the condensate collected in cold traps which were immersed in ice water and dry ice-acetone, respectively. In these compounds, five kinds of volatile organic acids such as acetic acid, butyric acid, iso-valeric acid, valeric acid, and caproic acid were identified. 3) Eleven peaks were detected from the head space vapor collected in cold trap which is immersed in liquid nitrogen. Volatile amines identified in these components are as follows; methylamine, trimethylamine, dimethylamine, ethylamine, and iso-propylamine.

• Journal of the Korean Geotechnical Society
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• v.32 no.12
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• pp.33-43
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• 2016

In order to analyze ground relaxation and cavity formation mechanism due to deteriorated sewer pipe, field test was carried out and a numerical assessments were compared with the field test results. An artificial underground cavity was intended using the ice block overlaying the buried pipe and confirmed that the cavity and relaxation of the surrounding ground were gradually formed as the ice block starts to melt down. Such mechanism was highly suspected to be involved with soil particle interlocking as a soil compaction was a typical process for the buried pipes. In exploring such mechanism numerically, commercially available DEM (Discrete Element Method) code PFC2D was used and the interlocking induced cavern behaviors were successfully simulated and compared with field test results by utilizing the clump logic imbedded in PFC code.

• World Technopolis Review
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• v.3 no.3
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• pp.139-152
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• 2014

The current transportation regime is largely based on two alternatives: (1) fixed route public transit, and (2) private ownership of internal combustion engine (ICE) powered vehicles per households. This paper analyzes one possible transportation alternative, Micro Electric Vehicles or MEVs, and compares with the ICE vehicles in terms of social, economic and environmental benefits, especially emphasizing its environmental advantage over ICE vehicles for future sustainability. While some representative models of MEVs exist in a limited market capacity, but global technical standards are generally insufficient and non-homogenous across nations, which restricts the development of the proposed transportation sector. The focus of this paper is to analyze the characteristics and potential benefits of MEVs in economical and environmental perspectives, including development status and technical standards, with a particular focus in the E.U., the U.S., Japan, and Korea. Based on the data of analysis, this paper aims to derive and propose a cooperative and adaptive global policy framework designed to speed up adoption and expansion of the global MEV market, including passenger and utility vehicles. We propose MEV to be a new mobility segment in the global transportation market because of their advantage in environmental impact, sustainability, overall cost of ownership, and safety.