• The Journal of Engineering Geology
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• v.25 no.2
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• pp.291-298
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• 2015

For hydrogeological studies, it is of importance to observe hydraulic head in order to interpret groundwater flow, characterize aquifers, and calibrate groundwater flow model. This study analyzed the zonal variation of hydraulic heads at the eight monitoring wells (GM-1~GM-8) installed with multi-packers in a coastal area and verified vertical and lateral trends of the hydraulic gradients. Hydraulic heads were expressed as the depth of water because the monitoring wells have different depths. The hydraulic gradient at the nearest well (GM-5) shows 0.0142 with increasing trend of hydraulic gradient along depth. This fact indicates typical phenomenon of the discharge area. On the other hand, GM-1 and GM-2 wells in coastal area demonstrate constant hydraulic gradient down to the depth of 100 meters while at the zone of deeper than 100 m the hydraulic gradients illustrate 0.0196 and 0.0735, respectively. This indicates that horizontal flow is dominant at shallower zone than 100 m whereas upward flow is dominant at the zone deeper than 100 m. GM-3 well located farther than the other wells from the coast shows a small hydraulic gradient of 0.0046 that evidences a prevalent horizontal flow between the recharge area and the discharge area.

• Journal of the Korean earth science society
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• v.36 no.6
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• pp.520-532
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• 2015

In order to understand the Holocene sea level changes in the eastern Yellow Sea, the west coast of Korea, and to compare the rates of sea level rise in each period of time, the geological proxy records for pre-instrumental era and measurement data for the present day were combined and analysed. The sea level in the Yellow Sea rose fast with a rate of about 10 mm/yr during the early Holocene, and decelerated down to 1 mm/yr since the mid to late Holocene. The rising rates of sea level in the 20th century were slightly higher than those in the late Holocene. The present-day rates of sea level rise, known as the 'rapid' rise, are in fact much lower or similar, compared to the early to mid Holocene sea levels in the study area. Recent tide-gauge data show that sea level rise in the eastern Yellow Sea has been accelerating toward the 21st century. These rising trends coincide well with global rising patterns in sea level. Additionally, the present-day rising trends of sea level in this study are correlated with increased rates of carbon dioxide concentrations and sea surface temperatures, further indicating a signal to global warming associated with the human effect. Thus, the sea level changes induced by current global warming observed in the eastern Yellow Sea and world's oceans can be considered as 'Anthropocene' sea level changes. The changes in sea level are based on instrumental measurements such as tide-gauges and satellite altimetry, meaning the instrumental era. The Holocene changes in sea level can thus be reconstructed from geological proxy records, whereas the Anthropocene sea-level changes can be solely based on instrumental measurements.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.571-580
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• 1985

Based on the data collected by R/V "Shinkai Maru" of the Japan Marine Fishery Resources Research Center during the period from April 1978 to April 1979, seasonal migration of Merluccius hubbsi was studied using the catch per fishing effort (tons/30 min. haul) and gonad maturity index (gonad weight /body weight X $10^3$). Merlurccius hubbsi are found in the area between $36^{\circ}S\;and\;54^{\circ}S$ along the coast of Arzentine and are abundant especially above the 100 fathoms in northern offshore of $48^{\circ}S$. It was observed that critical maturity body lengths (spawning minimum body length) in terms of gonad maturity index are 40 cm and 30cm in female and male respectively, while spawning seasons are from December to January and from November to December for female and male respectively. It was assumed that while the group which distrbutes in the north ($36^{\circ}S{\sim}39^{\circ}S$) in spring moves down south to $42^{\circ}{\sim}46^{\circ}S$ for spawning in summer (from December to January), the group which does not move or a part of this group which comes back to the north spawn in the area north of $42^{\circ}S$ throughout the long period except winter time (from July to August). Southern group as well might move north and spawn after mixing together with northern group at $42^{\circ}{\sim}46^{\circ}S$ area around the period of December to January,

• Journal of the Korean Magnetics Society
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• v.24 no.6
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• pp.197-201
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• 2014

As the importance of rare metal is increasing globally, Japan introduced the concept of Strategic Elements in 2004, and started Strategic Elements Project in 2007. The Goal of this project run by MEXT (Ministry of Education, Culture, Sports, Science and Technology) is to develop high-function materials and components that do not use rare or harmful elements by studying the role and characteristics of the elements that compose materials and components and decide their functions and characteristics. In September 2010, Japanese coast guard arrested a Chinese fishing boat near Senkaku Islands (Diaoyudao Islands by China), which escalated to the territory issue and eventually a big diplomatic and economic conflict. In order to put pressure on Japanese Government, China used an economic option, which is the ban of rare earth export to Japan. This incident doubled Japan's motivation to develop Strategic Elements and put more efforts into this Project. MEXT set the following three research areas in February 2012: Study of alternative materials using sufficient and harmless elements, Study of applications for the high-functions of Strategic Elements, Study of practical design for components using Strategic Elements. Through a course of gathering the opinion of professionals, MEXT settled down with the following 4 research and study areas for the Strategic Elements Project in June 2012. 1. Magnetic materials to replace Dy, Nd. 2. Catalyst/Battery materials to replace Pt, Rh/Li, Co. 3. Electronic materials to replace In, Ta. 4. Structural materials to replace Nb, Mo. This paper deals with the first area and reviews the results of the research and study as of now.

• Nutrition Research and Practice
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• v.11 no.1
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• pp.3-10
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• 2017

BACKGROUND/OBJECTIVES: Sargassum horneri is an edible brown alga that grows in the subtidal zone as an annual species along the coasts of South Korea, China, and Japan. Recently, an extreme amount of S. horneri moved into the coasts of Jeju Island from the east coast of China, which made huge economic and environmental loss to the Jeju Island. Thus, utilization of this biomass becomes a big issue with the local authorities. Therefore, the present study was performed to evaluate the anti-inflammatory potential of crude polysaccharides (CPs) extracted from S. horneri China strain in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. MATERIALS/METHODS: CPs were precipitated from S. horneri digests prepared by enzyme assistant extraction using four food-grade enzymes (AMG, Celluclast, Viscozyme, and Alcalase). The production levels of nitric oxide (NO) and pro-inflammatory cytokines, including tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-$1{\beta}$ were measured by Griess assay and enzyme-linked immunosorbent assay, respectively. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), nuclear factor (NF)-${\kappa}B$, and mitogen-activated protein kinases (MAPKs) were measured by using western blot. The IR spectrums of the CPs were recorded using a fourier transform infrared spectroscopy (FT-IR) spectrometer. RESULTS: The polysaccharides from the Celluclast enzyme digest (CCP) showed the highest inhibition of NO production in LPS-stimulated RAW 264.7 cells ($IC_{50}$ value: $95.7{\mu}g/mL$). Also, CCP dose-dependently down-regulated the protein expression levels of iNOS and COX-2 as well as the production of inflammatory cytokines, including TNF-${\alpha}$ and IL-$1{\beta}$, compared to the only LPS-treated cells. In addition, CCP inhibited the activation of NF-${\kappa}B$ p50 and p65 and the phosphorylation of MAPKs, including p38 and extracellular signal-regulated kinase, in LPS-stimulated RAW 264.7 cells. Furthermore, FT-IR analysis showed that the FT-IR spectrum of CCP is similar to that of commercial fucoidan. CONCLUSIONS: Our results suggest that CCP has anti-inflammatory activities and is a potential candidate for the formulation of a functional food ingredient or/and drug to treat inflammatory diseases.

• Journal of The Geomorphological Association of Korea
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• v.21 no.4
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• pp.149-164
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• 2014

The representative landscapes in Jeju Island called as Ten sceneries of Yeongju originates with Ten sceneries of Tamra which were organized in the late seventeenth century by Jeju governor Lee Iktae. In order to compose ten representative sceneries in Jeju Island, he selected four strongholds such as Jocheon, Byeolbang, Seogwi and Myeongwol and six places of scenic beauty such as Seongsan, Baekrokdam, Yeonggok, Cheonjiyeon, Sanbang and Chwibyeongdam, and made a painting named as Ten sceneries of Tamra. Since the scenes of strongholds also exhibit a lot of geomorphic landscapes, the painting could be considered a collection of representative landforms in Jeju Island. The painting depicts several types of landform such as volcano, crater, river, waterfall, pool, wetland, cavern, tor and rocky coast. The volcanic edifice appears most frequently in the painting, reflecting the particular emotion of Jeju people on Mt. Halla and oreums. However, another volcanic landform, a lava tube, was not highly evaluated due to its negative images. Three famous waterfalls in Jeju Island were included in Ten sceneries of Tamra, and it suggests that they are essentially outstanding landforms, and besides, there are few sites related with fresh water in Jeju Island. The ten sceneries were entirely organized in spite of the limitation of selecting places at that time. The landscape images of Jeju Island, which had been shared as collective representation by Jeju people, were firstly externalized through Lee Iktae's painting, and have long been passed down and established a kind of scenic stereotype.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.280-284
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• 1989

The soil texture and the physico-chemical characteristics of 442,000ha reclaimable tide land in the south-western of korean peninsular were analysed. The subsidence which may occur as the soil ripened was studied. The results were as follows : 1. Among the 257,000ha of existing reclaimed tidal land 53.0% was tine silty soil and 36.0% coarse silty, 6.0% coarse loamy and 5.0% sandy soils, respectively. 2. Out of the total 442,000ha of reclaimable tidal land, 51.0% was coarse silty soil, and 20% sandy, 15.0% coarse loamy and 14.0% fine silty textural family, respectively. The coarse silty deposits were mainly distributed in the Gyeong gi and Jeonnam coast, while the coarse deposits(Coarse Loamy-sandy) exist in the Jeonbuk coastal area, but in the Chungnam areas there were various textural grades. 3. Reclaimable tidal Land in the south-western part of the peninsular was Classified into saline and alkaline soil. Electric Conductivity in saturation extract was extremely high that was 46~51 mmhos/cm, E.S.P was more than 25% and pH was ranged around 7.5~8.0 4. Reclaimed to cultivated field the subsidence reclaimable tide land to be expected when was about 18% in Soil and 21% in Sicl soils calculated down to 1.25m of the profile.

• Tribology and Lubricants
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• v.35 no.1
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• pp.44-51
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• 2019

The paper presents the rotordynamic performance measurements and model predictions of a fuel cell electric vehicle (FCEV) air compressor supported on gas foil bearings (GFBs). The rotor has an impeller on one end and a thrust runner on the other end. The front (impeller side) and rear (thrust side) gas foil journal bearings (GFJBs) are located between the impeller and thrust runner to support the radial loads, and a pair of gas foil thrust bearings are located on both sides of the thrust runner to support the axial loads. The test GFJBs have a partial arc shim foil installed between the top foil and bump strip layers to enhance hydrodynamic pressure generation. During the rotordynamic performance tests, two sets of orthogonally installed eddy-current displacement sensors measure the rotor radial motions at the rotor impeller and thrust ends. A series of speed-up and coast-down tests to 100k rpm demonstrates the dominant synchronous (1X) rotor responses to imbalance masses without noticeable subsynchronous motions, which indicates a rotordynamically stable rotor-GFB system. Finite element analysis of the rotor determines the rotor free-free (bending) natural modes and frequencies well beyond the maximum rotating frequency. The predicted damped natural frequencies and damping ratios of the rotor-GFB system reveal rotordynamic stability over the speeds of interest. The imbalance response predictions show that the predicted critical speeds and rotor amplitudes strongly agree with the test measurements, thus validating the developed rotordynamic model.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.219-225
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• 2022

1950-meter-tall goddess is Seolmundae Grandmother with the head of the 1950m Hallasan Mountain Baengnokdam and the body of the mountain ridgeline. Seolmundae Grandmother in Jeju is a folk belief that has been passed down from generation to generation in Jeju. Unlike inland, Seolmundae Grandmother, which had femininity in the customs of Jeju, which was a matrilineal society, developed into an absolute faith in Jeju, metaphorizing that in some way it was inevitable. Seolmundae Grandmother was the only subject that could mentally solve the biggest problem for Jeju residents, even if they were disconnected from the mainland. In other words, Seolmundae Grandmother was unable to make underwear for Seolmundae Grandmother because it was short of 100 bottles of silk, the god of Hallasan, a huge being and a physical symbol. Therefore, Semyungju Grandmother gave up the bridge connecting the mainland and Jeju. In this paper, focusing on the fact that Mt. Halla, covered with snow in winter, is like a skein of silk thread that we usually use in our daily lives, the etymology of Seolmundae has been changed to Saengmyeongju, - Semyungju, which is a skein of fine silk. As a basis for this, there is a custom of tying a thread of silk in 'Semyungju', a shrine to Semyeongju in Halmangdang, 'Hanmosal' along the coast of Pyoseon-myeon. The silk thread is the core of the Packing DNA gene. The summit of Mt. Halla, Ninety-Nine Valleys, and five hundred generals, found in Seolmundae Grandmother or White Silk, expressed the symbols of Jeju. The Packing DNA gene was found to originate in the Jeongnang

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.554-562
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• 2022

Humans technological advancements have resulted in the depletion of whale resources. Accordingly, the International Whaling Commission was established to preserve whale resources and ensure the orderly development of the whaling industry. After a commercial whaling moratorium came into effect, the international trade of whale meat and related products was banned. However, There is a systematic activity through illegal remodeling ships because whales incidentally caught may be distributed in Korea and have a significant economic benefit. Although suspected illegal whaling is actively cracked down, but it is still insufficient to prevent illegal whaling and distribution. To prevent this, stereoscopic crackdowns utilizing air forces and patrol ships are effective, and it is necessary to quickly separate the captured ship and crew to prevent the destruction of evidence. For the transparent distribution of whale meat, it is necessary to advance related technologies such as whale species identification and individual identification of forensic science institutions based on whale DNA database of the National Institute of Fisheries Science. Accordingly, the Korea Coast Guard Research Center is directly conducting research on related national R&D project. To increase the efficiency of identifying whale-related evidence at crime scene, a rapid test kit that responds specifically to whale bloodstrains is developing and evidence transport packs are manufacturing and distributing, while identification technologies are also being advanced.