• The Journal of the Petrological Society of Korea
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• v.7 no.2
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• pp.111-131
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• 1998

The migmatitic gneiss in the Odesan Gneiss Complex has small amount of quartzite, amphibolite and marble and the Kuryong Group which contact with migmatitic gneiss unconformitly, also contains some amphibolite. Preview studies of this area had regarded that the amphibolites contact with marble had been produced by metasomatism from the pelitic and calcareous sediments mixtures, but the amphibolite is reinterpreted as igneous origin. $SiO_2$ content of the amphibolite is 45.9~52.7 wt%, which corresponds to basaltic composition. MgO content has narrow range (4.6~6.87 wt%) and major and trace element are plotted against MgO,$TiO_2, P_2O_5$, Hf, Zr are reduced and Cr and Ni are increased their content with increasing MgO. This phenomenon indicates that the basaltic magma as the protolith of the amphibolite had frationated with the crystallization of the pyroxene and/or olivine. REE pattern has smoothly decrease from LREE to HREE. Eu/Eu(0.83~1.19) show the flat Eu anomaly, which indicate small fractional crystallization of plagioclase. HREE is enriched in the garnet-bearing amphibolites. Several discrimination diagram for the basaltic magma show that the amphibolite of the study area is originated tholeiitic basaltic magma indicating continental rift environment. Due to determine the metamorphic condition garnet-hornblende geothermometry and hornblende-plagioclase geobarometry are used. Peak metamorphic temperature range of the amphibolite $788~870^{\circ}C$ and is deduced toward the northeastern part. The calculated temperature from the amphibolite has slightly higher than the temperature of the metapelites but the trend of metamorphic grade which decrease from western to eastern part progradly is similar to each other. The metamorphic pressure calculated by garnet- hornblede-plagioclase geobarometry is 4~5kb. But ilmenite-plagioclase pair enclosed in garnet show 8 kb at $700^{\circ}C$ by garnet-ilmenite-rutile-plagioclase geobarometery. The zonal profile of garnet in sample 84 shows the bell-shape profile, which grossular content decreases whereas pyrope content increases progressively. This means that the amphibolite has undergone the clockwise P-T-t path which is shown in the migmatitic gneiss of the Odesan Gneiss Complex.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.21-28
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• 2007

This study was conducted to investigate how the qualities of the stream water vary during the event in the regrowth and rehabilitation catchments in Yangju, Gyeonggido, from June to September 2005. During the observation periods, we sampled the stream water continuously by an auto-sampler (ISCO, 6712FR). The sampled waters were analyzed for suspended solid concentration, electrical conductivity and pH. The suspended solid concentration during the event increased concurrently with the stream flow. The peak of suspended solid concentration usually precedes the peak flow. The maximum value of suspended solid concentration was 420.89 mg/l in the event 1 at the regrowth catchment. Among the events simultaneously sampled at both catchments, the maximum values of suspended solid concentration were 212.8 mg/l and 58.24 mg/l in the event 3 at the regrowth and rehabilitation catchment respectively. The maximum value of EC in each event showed in the early stage of rising limb. EC decreased during the rising limb, and then showed minimum value at peak flow. EC gradually increased to pre-event value after minimum one. pH varied in similar pattern with EC. The maximum value of suspended solid concentration during each event was 2.8 to 4.3 times higher at the regrowth catchment than at the rehabilitation catchment. And the EC during each event was higher at the regrowth catchment than at the rehabilitation catchment. This results indicate that a disturbed forest soil during clear cutting at regrowth catchment still has been unstable.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.2
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• pp.332-350
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• 2019

Zonal hydrographic section measurements at $39.7^{\circ}N$ were conducted between $129.0^{\circ}E$ and $131.3^{\circ}E$ from August 7 to 25 in 2017 using an underwater glider. The glider traveled about 440 km for about 18 days along the 106 line of the regular shipboard measurements in the National Institute of Fishery Science (NIFS) and obtained twice a hydrographic section with high horizontal resolution. Even under the strong East Korea Warm Current with maximum speed of 0.8 m/s across the section, the glider successfully maintained the designated path within an RMS distance of 400 m. By comparing with the NIFS shipboard hydrographic section, it is confirmed that high spatial resolution measurements obtained from a glider were necessary to properly observe front and eddy variability in the East Sea where a typical spatial scale is smaller than the open oceans. From the glider section measurements, a new lens-shaped eddy was found in the thermocline. The lens-shaped anticyclonic eddy had 10~13 km in horizonal width and about 200 m in height like a typical submesoscale eddy resided within the thermocline, which was firstly named as Korea intrathermocline eddy (Keddy). The Keddy has the distinguishing characteristics of a typical intrathermocline eddy, such as a central core with anomalously weak stratification, a convex shaped lens bounded by the stratification anomaly, an interior maximum of velocity at 170 m, no surface appearance of the geopotential field, a small or comparable horizontal width relative to the first baroclinic Rossby radius of deformation, and the Rossby nubmer of 0.7.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.461-472
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• 2022

Natural and anthropogenic factors cause forest types to continuously change. Since the ratio of forest area by forest type is important information for identifying the characteristics of national forest resources, an accurate understanding of the prospect of forest type change is required. The study aim was to use National Forest Inventory (NFI) time-series data to understand the characteristics of forest type change and to estimate future prospects of nationwide forest type change. We used forest type change information from the fifth and seventh NFI datasets, climate, topography, forest stand, and disturbance variables related to forest type change to analyze trends and characteristics of forest type change. The results showed that the forests in Korea are changing in the direction of decreasing coniferous forests and increasing mixed and broadleaf forests. The forest sites that were changing from coniferous to mixed forests or from mixed to broadleaf forests were mainly located in wet topographic environments and climatic conditions. The forest type changes occurred more frequently in sites with high disturbance potential (high temperature, young or sparse forest stands, and non-forest areas). We used a climate change scenario (RCP 8.5) to establish a forest type change model (SVM) to predict future changes. During the 40-year period from 2015 to 2055, the SVM predicted that coniferous forests will decrease from 38.1% to 28.5%, broadleaf forests will increase from 34.2% to 38.8%, and mixed forests will increase from 27.7% to 32.7%. These results can be used as basic data for establishing future forest management strategies.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.40-50
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• 2024

Pine forests are continuously declining due to competition with broadleaf trees, such as oaks, as a consequence of changes in the natural dynamics of forest ecosystem. This natural decline creates a risk of losing the various benefits pine trees have provided to people in the past. Therefore, it is necessary to prepare future forest management directions by considering the state of pine tree decline in each region. The goal of this study is to understand the characteristics of pine forest changes according to forest dynamics and to predict future regional changes. For this purpose, we evaluated the trend of change in pine forests and extracted various variables(topography, forest stand type, disturbance, and climate) that affect the change, using time-series National Forest Inventory (NFI) data. Also, using selected key variables, a model was developed to predict future changes in pine forests. As a results, it showed that the importance of pine trees in forests across the country has decreased overall over the past 10 years. Also, 75% of the sample points representing pine trees remained unchanged, while the remaining 25% had changed to mixed forests. It was found that these changes mainly occurred in areas with good moisture conditions or disturbance factors inside and outside the forest. In the next 10 years, approximately 14.2% of current pine forests was predicted to convert to mixed forests due to changes in natural forest dynamics. Regionally, the rate of pine forest change was highest in Jeju(42.8%) and Gyeonggi(26.9%) and lowest in Gyeongbuk(8.8%) and Gangwon(13.8%). It was predicted that pine forests would be at a high risk of decline in western areas of the Korean Peninsula, including Gyeonggi, Chungcheong, and Jeonnam. This results can be used to make a management plan for pine forests throughout the country.

• Journal of Korean Home Economics Education Association
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• v.36 no.2
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• pp.65-88
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• 2024

This study aims to explore the knowledge structure of the field of home economics education. To achieve this, the knowledge network of the field of home economics education was analyzed using social network analysis on 758 articles published between 2004 and 2023, focusing on those in the Journal of Home Economics Education Research. The main findings of the study are as follows: First, the knowledge network exhibited characteristics of a small-world network. Papers on children, family, and career maturity significantly influenced the knowledge structure. Second, the knowledge structure is centered around the home economics subject and curriculum and is organized into four groups. A temporal analysis revealed that the influence of core keywords such as perception, content, unit, home economics teachers, practice, behavior, and influence has decreased, while the influence of curriculum, textbook, and development has shown a trend of increasing. Third, the sub-knowledge structures were identified as seven categories. The study found that the influence of 'perception and demand for home economics education' is decreasing, whereas the influence of 'home economics curriculum and textbooks' and 'application of home economics teaching and learning process' is increasing. Additionally, 'adolescent self-esteem and family relationships' and 'home economics curriculum and textbooks' were found to be the most influential in the knowledge structure of home economics education. This research is significant as it demonstrates the temporal changes in the core keywords and sub-structures of the knowledge structure within the field, thereby providing a foundation for understanding and expanding the research knowledge structure in the field of home economics education.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.227-234
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• 2009

Using a finite volume ocean circulation model based on an unstructured grid (FVCOM), we studied the structure of a fresh water bulge that influences on the Region Of Freshwater Influence. Fresh water discharged a river forms a coastal boundary current to the righthand side and a cyclonically circulation freshwater bulge that grows with time. In the middle of the bulge, vertical motions bring fresh water to the bottom. When tidal motions are included, the bulge disappears while the boundary currents becomes wider. Through a simple comparison of areas occupied low salinity water we quantified vertical and horizontal mixing due to the tide and showed that the tidal motion enhances the vertical mixing. During the first few tidal cycles right after the onset of the river discharge, due to tidal excursion the horizontal mixing becomes stronger. The vertical mixing by the tide mixes the fresh water After a certain time the water around the river mouth is well mixed and the horizontal excursion of the fresh water near the river mouth does not have much effect on the horizontal mixing. When there is no tidal motion horizontal mixing is mainly by the inertial instability at the surface and the horizontal mixing becomes stronger over time.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.3
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• pp.149-157
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• 2005

Typical water quality (WQ) parameters defined in the governing equation of the WQ model are the pollutant loads from atmosphere and watersheds, pollutant release rates from sediment, diffusion coefficient and reaction coefficient etc. The direct measurement of these parameters is very difficult as well as requires high cost. In this study, the pollutant budget equation including these parameters was used to construct the linear simultaneous equations. Based on these equations, the inverse problems were constructed and WQ parameter estimation method minimizing the sum of squared errors between the computed and observed amounts of the mass changes was suggested. WQ parameters, i.e., the atmospheric pollutant loads, sediment release rates, diffusion coefficients and reaction coefficient, were estimated using .this method by utilizing the vertical concentration profile data which has been observed in Cheonsu Bay and Ulsan Port. Values of the estimated parameters show a large temporal variation. However, this technique is persuasive in that the RHS (root mean square) error was less than $5.0\%$ of the observed value ranges and the agreement index was greater than 0.95.

• Journal of Service Research and Studies
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• v.6 no.2
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• pp.99-116
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• 2016

The purpose of this paper is to see what the problem is and what the direction of the strategy of asset management after this study has analyzed asset management status of domestic life insurance companies according to interest rate trends, analyzing in time series management asset lists, asset distribution state, and securities list of life insurance companies during 2000~2014. It has carried correlation analysis and regression analysis between yield and bond interest KOSPI index. As the study result, life insurance companies have managed assets in stability than profitability. The correlation coefficient between interest rate and performance rates of total asset, management asset and securities is highly plus, correlation of management asset performance rate is higher than that of total asset performance rate, and the correlation of securities performance rate is higher than that of management asset performance rate. The correlation coefficient of KOSPI and performance rate shows minus. The suggestion is that the change of asset management is required as the interest decline rises up a reverse margin risk because of the asset management of stability.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4D
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• pp.613-622
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• 2011

The aim of this study is to provide fundamental references for the establishment of environmental policies by using and evaluating EPI (Environmental Performance Index). Data of EPI for this study come from the 2010 World Economic Forum. By using these variables, we have comparison analysis of EPI of 163 countries. Next, the object of similarity analysis using MDS is the OECD countries and shown on PREMAP, drawing the position of each nation in environmental category and environmental policy index. The result of this study shows that there are differences in environmental policy index according to each nation's income and furthermore, similarity analysis makes it possible to locate environmental policy index of each nation in an awareness, which would help to set directions of policies concerning environment through the comparison with other advanced countries. But it could be more worth investigating time-series analysis for the change of environment-related variables because EPI has been just four times published since its first announcement in 2002. Despite, such limits would be overcome through continuous data collected over time.