• Proceedings of the Korean Quaternary Association Conference
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• 2004.11a
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• pp.37-43
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• 2004

The response of the CCCma coupled climate model to the imposition of LGM conditions is investigated. The global mean SAT and SST decrease by about $10^{\circ}C$ and $5.6^{\circ}C$ in the coupled model. Tropical SST decreases by $6.5^{\circ}C$, whereas CLIMAP reconstructions suggest that the tropics cool by only about $1.7^{\circ}C$, although the larger tropical cooling is consistent with the more recent proxy estimates. With the incorporation of a full ocean component, the coupled model gives a realistic spatial SST pattern, capturing features associated with ocean dynamics that are seen in the CLIMAP reconstructions. The larger decrease of the surface temperature in the model is associated with a reduction in global precipitation rate (about 15%). The tropical Pacific warm pool retreats to the west and a mean La $Ni\tilde{n}a$-like response is simulated with less precipitation over the central Pacific and more in the western tropical Pacific. The more arid ocean climate in the LGM results in an increase in SSS almost everywhere. This is particularly the case in the Arctic Ocean where large SSS increase is due to a decrease in river discharge to the Arctic Ocean associated with the accumulation of snow over the ice sheet, but in the North Atlantic by contrast SSS decreases markedly. This remarkable reduction of SSS in the North Atlantic is attributed to an increase in fresh water supply by an increase in discharges from the Mississippi and Amazon rivers and an increase in P-E over the North Atlantic ocean itself. The discharges increase in association with the wetter LGM climate south of the Laurentide ice sheet and in South America. The fresh water capping of the northern North Atlantic results in a marked reduction of deep convection and consequently a marked weakening of the North Atlantic overturning circulation. In the LGM, the maximum overturning stream function associated with the NADW formation decreases by about 60% relative to the control run, while in the Southern Ocean, oceanic convection is stronger in the LGM due to reduced stratification associated with an increase in SSS and a decrease in SST and the overturning stream function associated with the formation of AABW and the outflow increases substantially.

• Smart Structures and Systems
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• v.26 no.3
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• pp.291-309
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• 2020

To study oceanic and meteorological problems related to climate change, Korea has been operating several ocean research stations (ORSs). In 2011, the Gageocho ORS was attacked by Typhoon Muifa, and its structural members and several observation devices were severely damaged. After this event, the Gageocho ORS was rehabilitated with 5 m height to account for 100-yr extreme wave height, and the vibration measurement system was equipped to monitor the structural vibrational characteristics including natural frequencies and modal damping ratios. In this study, a mass reallocation method is presented for structural model updating of the Gageocho ORS based on the experimentally identified natural frequencies. A preliminary finite element (FE) model was constructed based on design drawings, and several of the candidate baseline FE models were manually built, taking into account the different structural conditions such as corroded thickness. Among these candidate baseline FE models, the most reasonable baseline FE model was selected by comparing the differences between the identified and calculated natural frequencies; the most suitable baseline FE model was updated based on the identified modal properties, and by using the pattern search method, which is one of direct search optimization methods. The mass reallocation method is newly proposed as a means to determine the equivalent mass quantities along the height and in a floor. It was found that the natural frequencies calculated based on the updated FE model was very close to the identified natural frequencies. In conclusion, it is expected that these results, which were obtained by updating a baseline FE model, can be useful for establishing the reference database for jacket-type offshore structures, and assessing the structural integrity of the Gageocho ORS.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.63-69
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• 2008

It has an important meaning that the maintenance and management of facility for a onshore construction shall be damaged by oceanic environment. A movement and displacement of these shall be investigated by up-to-date machinery tools like GPS and Lidar and MBES & Gyro. In current a lot of tools and methods for investigation shall be used as a displacement and movement on land mainly. For underwater facility it is very difficult to check because of special conditions below the water surface. In this study, a surveying methods for a movement and displacement of underwater facility as caisson shall be used, i.e. multibeam-echo-sounding system. A possibility as basic data for displacement and environmental monitoring shall be studied by MBES to acquire a caisson's inclination.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.559-572
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• 2019

In the southeast sea of Korea, the cold water is concentrated in every summer, showing in abnormal oceanic conditions. Cold water occurred in the southeast sea is dominantly influenced by wind, which occurs when the south wind is continuously blowing for 3 to 7 days more. In this study, water temperature, wind speed and direction data of KMA, KHOA and KHNP, Chlorophyll-a of COMS/GOCI, GHRSST Level 4 SST of NASA, and red tide alert data of the National Institute of Fisheries Science were used to analyze the correlation between occurrence and change of the cold water and the red tide of Cochlodinium polykrikoides. The upwelling cold water mass showed a characteristic of moving northward along the current and occurrence a high concentration of chlorophyll along the water mass. Also, when the warm current were strong, the characteristic of red tide showed a northward moving.

• Journal of Coastal Disaster Prevention
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• v.4 no.4
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• pp.189-196
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• 2017

Ocean Research Stations (ORSs) is the ocean platform type observation towers and measured oceanic, atmospheric and environmental data. These station located on the offshore area far from the coast, so they can produce the data without land effect. This study focused to improve the wave data quality of ORS station. The wave observations at ORSs are used by the C-band (5.8 GHz, 5.17 cm) MIROS Wave and Current Radar (MWR). MWR is convenient to maintenance and produce reliability wave data under bad weather conditions. MWR measured significant wave height, peak wave period, peak wave direction and 2D wave spectrum, so it's can provide wave information for researchers and engineers. In order to improve the reliability of MWR wave data, Datawell Waverider Buoy was installed near the one ORS (Socheoncho station) during 7 months and validate the wave data of MWR. This study found that the wave radar tend to be overestimate the low wave height under wind condition. Firstly, this study carried out the wave Quality Control (QC) using wind data, however the quality of wave data was limited. So, this study applied the four filters (Correlation Check, Direction Filter, Reduce White Noise and Phillips Check) of MWR operating software and find that the filters effectively improve the wave data quality. After applying 3 effective filters in combination, the RMSE of significant wave height decreased from 0.81m to 0.23m, by 0.58m and Correlation increased from 0.66 to 0.96, by 0.32, so the reliability of MWR significant wave height was significantly improved.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.6
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• pp.309-318
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• 2020

Besides respiratory infection, COVID-19 has many neurological symptoms not only loss of smell and taste but also fatigue and brain fog. But it is a challenge to treat the neurological symptoms especially of anosmia and ageusia. In order to search for the therapeutic methods, the geographical diversity and pathological mechanisms of the COVID-19 and two symptoms were investigated from the latest clinical studies. Because the environmental conditions of the monsoon climate zone of East Asia and the Mediterranean and Oceanic climate zone of Italy, Britain, United States and tropical Brazil are different, each of diverse etiology and internal milieu should be considered differently in the treatment. SARS-CoV-2 exhibits the dampness-like characteristics and the olfactory and gustatory disorders are particularly more common than other flu or cold. and it tends to show features of damaging the lung qi of olfaction and heart-spleen qi of gustation. The mechanisms of olfactory and gustatory loss are various according to precursory, inflammatory, non-inflammatory and sequelar forms, so the therapeutic method should be designed for each period and pathology. If the process of inflammation arises from nasal and respiratory, olfactory epithelium to the central nervous structure by way of blood brain barrier, the treatment should be corresponded with the stage and depth of pathogen place. And if the olfactory loss is asymptomatic or in the initial stage, it can be applied intranasal topical scent therapy to relieve temporary locking of qi movement, but maybe also used in parallel together with herbs of relieving dampness toxin latent in the lung parenchyma.

• Journal of the Korea Safety Management & Science
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• v.26 no.3
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• pp.51-57
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• 2024

The purpose of this study is to compare and analyze the impact range of explosion damage due to gas leaks at LPG filling stations, focusing on propane and butane, which are components of vehicle LPG. The scenarios were designed based on the explosion incident at an LPG filling station in Gangwon-do, where an actual gas leak accident occurred, resulting in Scenario I and Scenario II. The ALOHA program, developed by the U.S. National Oceanic and Atmospheric Administration (NOAA), was used as the tool to analyze the impact range of the explosion damage for both substances. The results of the study indicated that, under identical conditions, propane had a wider impact range of damage than butane. This is presumed to be due to the greater explosion energy of propane, attributable to its physicochemical properties. Therefore, when preparing for LPG leak accidents, measures for propane need to be prioritized. As safety measures for propane, two suggestions were made to minimize human casualties. First, from a preventive perspective, it is suggested to educate workers about propane. Second, from the perspective of response measures and damage minimization, it is suggested to thoroughly prepare emergency evacuation and rescue plans, evacuation routes, designated shelters, and emergency response teams. This study compares and analyzes the impact range of radiative heat damage based on LPG components. However, hazardous accidents are critically influenced by the type of leaking substance, the form of the leak, and meteorological factors affecting the diffusion pattern of the substance. Therefore, for future research, it is proposed to model various leakage scenarios for the same substance to conduct a comprehensive risk assessment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.77-85
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• 2002

In the southern sea of Korea and the areas of Tsushima warm currents the relationship between the distributions of eggs and larvae of anchovy (Engraulis japonica) and oceanic conditions was examined on July and August 1997, The south Korean coastal waters, the water temperature of below $20\~23^{\circ}$ and the salinity of above 33.0 (PSU), the mixed waters between the south Korean coastal waters and the Tsushima warm currents, $21\~25^{\circ}$ and $32.0\~32.5$ and the Tsushima warm currents, above $26^{\circ}$ and below 31.5 were distributed at the surface layer. The Tsushima warm currents were distributed at the northeast of Jeju Is. and off the southern sea of Korea. As an appearance of warm streamer, the mixed waters were intruded into the coastal areas of Komun Is.$\~$Sori Is. and Sori Is.$\~$Yokji Is.. Approximate paths of surface water by the drift card experiments were similar with the intrusions of the warm water identified from the water temperature and salinity distributions. The distributions of chlorophyll concentration were consistent with the distributions of water temperature and salinity, Anchovy eggs and larvae were mostly distributed at Komun Is., Yokji Is, and the southwest of Koie Is. where chlorophyll concentrations were high and cyclonic circulations by the warm water intrusions (warm streamers) were formed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.9
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• pp.871-877
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• 2015

Deep-sea equipment such as underwater robots and unmanned submersible vehicles, include various machine components and sensors, and it is important that their reliabilities be tested before use in the fields. This is necessary because they are affected by complex extreme-environment conditions, such as high pressures, extreme temperatures, and tidal forces that are present in the deep sea. We require test equipment that can conduct empirical tests in conditions that mimic these complex oceanic environments. In this study, we propose specifications that should be met, and a design plan for the primary components, which should limit their use to a maximum water pressure of 2.0 MPa, water temperature of $5{\sim}60^{\circ}C$, and a maximum flow velocity of 2 m/s. in work-in type underwater combined environment test equipment and. We present test system development procedures to verify the reliability of products and systems used in deep-sea environments.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.69-78
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• 2005

ARCO and TAO data which supply three dimensional global ocean information are assimilated to the background field from a general circulation model, MOM3. Using a variational Analysis using Filter (VAF), which is a spatial variational filter designed to reduce computational time and space efficiently and economically, observed ARGO and TAO data are assimilated to the OGCM-generated background sea temperature for the generation of initial condition of the model. For the assessment of the assimilation impact, a comparative experiment has been done by integrating the model from different intial conditions: one from ARGO-, TAO-data assimilated initial condition and the other from background state without assimilation. The assimilated analysis field not only depicts major oceanic features more realistically but also reduces several systematic model bias that appear in every current OGCMs experiments. From the 10-month of model integrations with and without assimilated initial conditions, it is found that the major assimilated characteristics in sea temperature appeared in the initial field remain persistently throughout the integration. Such implies that the assimilated characteristics of the reduced sea temperature bias is to last in the integration without rapid restoration to the non-assimilated OGCM integration state by dispersing mass field in the form of internal gravity waves. From our analysis, it is concluded that the data assimilation method adapted in this study to MOM3 is reasonable and applicable with dynamical consistency. The success in generating initial condition with ARGO and TAO data assimilation has significant implication upon the prediction of the long-term climate and weather using ocean-atmosphere coupled model.