• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.51-58
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• 1983

Off the southwest coast of Korea, changes in hydrographic fields from stratified state of summer to a vertically homogeneous one of winter appeared to occur most actively in November. During this transitional period coincident thermal and salinity fronts are formed along the boundary between the two water masses of cold coastal water with low salinity and of the Tsushima Current Water. Generally frontal zone lies where the bottom depth is about 70-90m except for the central region of the Cheju Strait in which the influence of the Tsushima Current is weak. Result of the drift bottle experiment in November 1930 supports the existence of the westward coastal current.

• Journal of the Korean Geotechnical Society
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• v.29 no.11
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• pp.73-84
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• 2013

When a slope failure or a debris flow occurs, a shear strength on failure plane becomes nearly zero and soil begins to flow like a non-cohesive liquid. A consistency of cohesive soils changes as a water content increases. Even a cohesive soil existing at liquid limit state has a small amount of shear strength. In this study, a water content, at which a shear strength of cohesive soils is zero and then cohesive soils will start to flow, was proposed. Three types of clays (kaolinite, bentonite and kaolinite (50%)+bentonite (50%)) were mixed with three different solutions (distilled water, sea water and microbial solution) at liquid limit state and then their water contents were increased step by step. Then, their undrained shear strength was measured using a portable vane shear device called Torvane. The ranges of undrained shear strength at liquid and plastic limits are 3.6-9.2 kPa and 24-45 kPa, respectively. On the other hand, the water content that corresponds to the value of the undrained shear strength changing most rapidly is called flow water content. The flow limit refers to the water content when undrained shear strength of cohesive soils is zero. In order to investigate the relationship between liquid limit and flow limit, the cohesive index was defined as a value of the difference between flow limit and liquid limit. The new plasticity index was defined as the value of difference between flow limit and plastic limit. The new liquidity index was also defined using flow limit. The values of flow limit are 1.5-2 times higher than those of liquid limit. At the same time, the values of new plasticity index are 2-5.5 times higher than those of original plasticity index.

• Journal of fish pathology
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• v.35 no.2
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• pp.185-193
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• 2022

This study investigated carnival behavior in the nursery stage of Fenneropenaeus chinensis. In order to suppress the carnival behavior and improve the survival rate, it was examined whether there was a carnivalism inhibitory effect according to the rearing water of shrimp. In addition, their blood physiological changes were observed. As a result, in the experimental group with the size difference of F. chinensis, the survival rate was the highest in the biofloc technology (BFT) rearing water of olive flounder (75%), and in the experimental group without the size difference, the survival rate was the highest in the seawater experiment group (93%). In both experimental groups, rate of carnival behavior was observed to be low in the fed experimental group regardless of the size difference of F. chinensis. As a result of blood cell analysis of F. chinensis according to the rearing water, the percentage of granulocytes was the highest in the BFT rearing water of flounder (75%) and the lowest in the filtered seawater group (66%). The proportion of semi-granulocytes was the highest at 11% in the shrimp BFT rearing water, and the lowest at 7% in the filtered seawater. The proportion of hyalinocytes was highest in filtered seawater (27%) and lowest in flounder BFT rearing water (16%). These results suggest that carnival behavior and blood composition of F. chinensis may be different depending on the conditions of the rearing water in the nursery stage.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.460-460
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• 2023

최근 범 지구적인 기후변화로 인해 집중호우가 빈번히 발생하고 침수피해가 증가하고 있다. 이에 따른 침수 피해 위험이 큰 지하상가, 지하 주차장, 반지하 주택 등의 침수 발생이 잦아지며 인명 및 재산 피해 발생이 커지고 있다. 이러한 지역은 인근 하수관로의 수위에 따라 침수 영향을 크게 받게 된다. 이에 따른 강우·유출 관계는 침수피해에 대해 대처하기 위해 시공간적 강우 특성이 반영된 하수관로 수위 예측이 중요하다고 판단된다. 이에 본 연구에서 수위 자료는 서울시 하수관로 수위 현황 자료를 활용하였으며, 강수량 자료는 서울 내 서초구 일대의 강수량 자료를 활용하여 연구를 진행하였다. 대상 지역은 저지대에 위치해 침수가 잦은 서초구 서초동으로 선정하였으며, 분석에 사용된 기간은 2012년부터 2021년까지의 수위 자료를 화용하여 이를 바탕으로 순환 신경망인 RNN의 일종이며, 다른 모델의 구조와 비교하여 더욱 간단하고 효율적인 ESN(Echo State Network) 알고리즘을 사용하여 수위 예측을 진행하였다. 분석을 위해 대상 지역의 강수 사상이 발생하여 하수관로의 수위의 변동이 큰 기간을 선정하여 분석을 실시하였다. 2012년부터 2018년까지의 자료를 학습(training) 자료로 활용하였으며, 모형의 검증 위해 통계분석을 실시하여 검증하였다.

• Journal of Haehwa Medicine
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• v.18 no.1
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• pp.117-127
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• 2009

Study on correspondent of eastern and western astrology and Jung's psychological types, we obtain as follow as results. Western astrology is transmitted from China and developed, it influenced on the study of the Four Pillars(四柱學). Comparing assemble, gathering, punishment, destruction, collision, impair of Di-zhi(地支) in the study of Four Pillars with Xing-gong theory(星宮論) in the western astrology, can get the result that the Pillars study has close connection with astronomy and astrology. When we compared Jung's psychological types with astrology, the five elements(五行) and the four major factors, can be summarized like this. (1) intuition-fire sign-wood and fire-fire in the four major factors(四大), (2) sensation-earth sign-earth and metal-earth in the four major factors, (3) thinking-air sign-metal and water-wind in the four major factors, (4) feeling-water sign-water and wood-water in the four major factors. The four major factors of Buddhism is now understood as, earth, water and fire represent the state of solid(earth), liquid(water), gas(fire) and wind can be recognized as energy source help the changes. This is mentioned throughout the books, but only arranging the theory of four major factors.

• Geomechanics and Engineering
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• v.22 no.3
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• pp.245-254
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• 2020

The interaction between the frozen soil and building structures deteriorates with the increasing temperature. A nuclear magnetic resonance (NMR) stratification test was conducted with respect to the unfrozen water content on the interface and a shear test was conducted on the frozen soil-structure interface to explore the shear characteristics of the frozen soil-structure interface and its failure mechanism during the thawing process. The test results showed that the unfrozen water at the interface during the thawing process can be clearly distributed in three stages, i.e., freezing, phase transition, and thawing, and that the shear strength of the interface decreases as the unfrozen water content increases. The internal friction angle and cohesive force display a change law of "as one falls, the other rises," and the minimum internal friction angle and maximum cohesive force can be observed at -1℃. In addition, the change characteristics of the interface strength parameters during the freezing process were compared, and the differences between the interface shear characteristics and failure mechanisms during the frozen soil-structure interface freezing-thawing process were discussed. The shear strength parameters of the interface was subjected to different changes during the freezing-thawing process because of the different interaction mechanisms of the molecular structures of ice and water in case of the ice-water phase transition of the test sample during the freezing-thawing process.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1115-1129
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• 2013

The study area is located on the western coast, and the inner development construction has been ongoing since 2011. The purposes of current study are to effectively simulate and quantitatively predict a temporal and spatial distributions of water temperature and salinity due to the stages of inner development construction in saemangeum reclaimed area. The transient-state numerical modeling using EFDC model is done, and the numerical simulation results are validated reasonably by repetitive numerical model calibration procedures with respect to field measurements of water temperature and salinity. The spatial distributions of water temperature and salinity show similar trends before and after construction of the dikes. In spring season, the salinity has maximum value of 21 psu, while, in summer season, the salinity shows 7 psu in a whole modeling domain. Thus, it is clearly observed that salt water is replaced by freshwater. However, the salinity and temperature reach their initial conditions at the end of the year. The salinity after construction of the dikes is lower than that before construction of them at Mankyeong area. On the other hands, after construction of the dikes, the salinity after dredging operations is higher than that before dredging. Because drastical increasing of water volume in Saemangeum Lake leads to increasing of stagnation time at bottom layer, and salt water is easily intruded to the two estuaries. Therefore, it may be concluded that hydrodynamic characteristics on Saemangeum are dominated by either Mankyeong and Dongjin discharge or sluice gates in/out-flow amounts, and thus they must be properly considered when rigorous and reasonable predictions of water temperature and salinity according to the stages of inner development construction.

• Journal of the Korean Geotechnical Society
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• v.33 no.4
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• pp.25-34
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• 2017

The soil-water characteristics is the most important state parameter for understanding changes in suction and water contents of unsaturated soil slopes. In the field, the hysteretic behaviors of drying and wetting soil-water characteristic curve are real and the adoption of path-dependent suction-water content is needed to predict the hydro-mechanical analysis of unsaturated soils. In this study, in-situ monitored hydraulic behavior of various soil slopes are compared with the data from numerical analysis with the laboratory soil water characteristic curve. Then, the verifications are performed based on the field monitored data respectively. Therefore, the use of path-dependent soil-water characteristic curves could be more rational for design and analysis of unsaturated soil slopes under rainfall conditions.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.14-14
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• 2011

Groundwater in the Waikatoregion is a valuable resource for agriculture, water supply, forestry and industries. The 434,000 ha study area comprises the upper Waikato River catchment from the outflow of Lake Taupo (New Zealand's largest lake) through to Lake Karapiro (a man-made hydro lake with high recreational value) (Figure 1). Water quality in the area is naturally high. However, there are indications that this quality is deteriorating as a result of land use intensification and deforestation. Compounding this concern for decision makers is the lag time between land use changes and the realisation of effects on groundwater and surface water quality. It is expected that the effects of land use changes have not yet fully manifested, and additional intensification may take decadesto fully develop, further compounding the deterioration. Consequently, Environment Waikato (EW) have proposed a programme of work to develop a groundwater model to assist managing water quality and appropriate policy development within the catchment. One of the most important and critical decisions of any modelling exercise is the choice of the modelling platform to be used. It must not inhibit future decision making and scenario exploration and needs to allow as accurate representation of reality as feasible. With this in mind, EW requested that two modelling platforms, MODFLOW/MT3DMS and FEFLOW, be assessed for their ability to deliver the long-term modelling objectives for this project. The two platforms were compared alongside various selection criteria including complexity of model set-up and development, computational burden, ease and accuracy of representing surface water-groundwater interactions, precision in predictive scenarios and ease with which the model input and output files could be interrogated. This latter criteria is essential for the thorough assessment of predictive uncertainty with third-party software, such as PEST. This paper will focus on the attributes of each modelling platform and the comparison of the two approaches against the key criteria in the selection process. Primarily due to the ease of handling and developing input files and interrogating output files, MODFLOW/MT3DMS was selected as the preferred platform. Other advantages and disadvantages of the two modelling platforms were somewhat balanced. A preliminary regional groundwater numerical model of the study area was subsequently constructed. The model simulates steady state groundwater and surface water flows using MODFLOW and transient contaminant transport with MT3DMS, focussing on nitrate nitrogen (as a conservative solute). Geological information for this project was provided by GNS Science. Professional peer review was completed by Dr. Vince Bidwell (of Lincoln Environmental).

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.1
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• pp.15-25
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• 2013

The RIMGIS(River Information Management GIS) has been developed since 2000 for public service and practical applications of related works after the standardization of national river data such as the river facility register report, river survey map, attached map, and etc. The RIMGIS has been improved in order to respond proactively to change in the information environment. Recently, Smart River-based river information services and related data have become so large as to be overwhelming, making necessary improvements in managing big data. In this study a plan was suggested both to respond to these changes in the information environment and to provide a future Smart River-based river information service by understanding the current state of RIMGIS, improving RIMGIS itself, redesigning the database, developing distribution, and integrating river information systems. Therefore, primary and foreign key, which can distinguish attribute information and entity linkages, were redefined to increase the usability of RIMGIS. Database construction of attribute information and entity relationship diagram have been newly redefined to redesign linkages among tables from the perspective of a river standard database. In addition, this study was undertaken to expand the current supplier-oriented operating system to a demand-oriented operating system by establishing an efficient management of river-related information and a utilization system capable of adapting to the changes of a river management paradigm.