• Korean Journal of Remote Sensing
• /
• v.37 no.6_1
• /
• pp.1589-1597
• /
• 2021

Submarine groundwater discharge (SGD) in coastal areas is gaining importance as a major transport route that bring nutrients and trace metals into the ocean. This paper describes the analysis of the seasonal changes and spatiotemporal characteristicsthrough the modeling monthly SGD for 35 years from 1986 to 2020 for the Nakdong river basin. In this study, we extracted 210 watersheds and SGD estimation points using the SRTM (Shuttle Radar Topography Mission) DEM (Digital Elevation Model). The average annual SGD of the Nakdong River basin was estimated to be 466.7 m²/yr from the FLDAS (Famine Early Warning Systems Network Land Data Assimilation System) recharge data of 10 km which is the highest resolution global model applicable to Korea. There was no significant time-series variation of SGD in the Nakdong river basin, but the concentrated period of SGD was expanded from summer to autumn. In addition, it was confirmed that there is a large amount of SGD regardless of the season in coastal area nearby large rivers, and the trend has slightly increased since the 1980s. The characteristics are considered to be related to the change in the major precipitation period in the study area, and spatially it is due to the high baseflow-groundwater in the vicinity of large rivers. This study is a precedentstudy that presents a modeling technique to explore the characteristics of SGD in Korea, and is expected to be useful as foundational information for coastal management and evaluating the impact of SGD to the ocean.

• Korean Journal of Remote Sensing
• /
• v.38 no.6_1
• /
• pp.1191-1205
• /
• 2022

Particulate matter(PM) among air pollutants with complex and widespread causes is classified according to particle size. Among them, PM_2.5 is very small in size and can cause diseases in the human respiratory tract or cardiovascular system if inhaled by humans. In order to prepare for these risks, state-centered management and preventable monitoring and forecasting are important. This study tried to predict PM_2.5 in Seoul, where high concentrations of fine dust occur frequently, using two ensemble models, random forest (RF) and extreme gradient boosting (XGB) using 15 local data assimilation and prediction system (LDAPS) weather-related factors, aerosol optical depth (AOD) and 4 chemical factors as independent variables. Performance evaluation and factor importance evaluation of the two models used for prediction were performed, and seasonal model analysis was also performed. As a result of prediction accuracy, RF showed high prediction accuracy of R² = 0.85 and XGB R² = 0.91, and it was confirmed that XGB was a more suitable model for PM_2.5 prediction than RF. As a result of the seasonal model analysis, it can be said that the prediction performance was good compared to the observed values with high concentrations in spring. In this study, PM_2.5 of Seoul was predicted using various factors, and an ensemble-based PM_2.5 prediction model showing good performance was constructed.

• Atmosphere
• /
• v.17 no.2
• /
• pp.207-216
• /
• 2007

The Moving-nest Typhoon Model (MTM) was installed on the Korea Meteorological Administration (KMA)'s CRAY X1E in 2006 and started its test operation in August 2006 to provide track and intensity forecasts of tropical cyclones. In this study, feasibility of the MTM forecast is compared with the Global Data Assimilation and Prediction System (GDAPS) of the KMA and the operational typhoon forecast models in the Japan Meteorological Agency (JMA), from the sixth tropical cyclone to the twentieth in 2006. Forecast skills in terms of the storm position error of the two KMA models were comparable, but MTM showed a slightly better ability. While both GDAPS and MTM produced larger errors than JMA models in track forecast, the predicted intensity was much improved by MTM, making it comparable to the JMA's typhoon forecast model. It is believed that the Geophysical Fluid Dynamics Laboratory (GFDL) bogus initialization method in MTM improves the ability to forecast typhoon intensity.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.20 no.2
• /
• pp.77-84
• /
• 2000

Eight-week old perennial ryegrass (Lolium perenne L. cv. Reveille) plants were exposed to different NO3-concentrations or osmotic stress with NaCI. Previously labeled "N was chased during 14 days of non-labeled'NO3 feeding in order to investigate NO3 metabolism in relation to osmoregulation. The short termmeasurement of osmotic potential showed that the extemal concentration of Nos- had not great effect on theosmotic potential, but that osmotic adjustment was observed in NaCl-treated plants. Total uptake of NO 3 - waslargely increased by increasing supply level of NO3 while it was depressed by exposing to osmotic stress.Nitrate reduction increased to more than 29% by increasing extemal NO,- concentration from 1 mM to 10mM. When osmotically stressed with NaCI, nitrate reduction was depressed to about 37% as compared to thecontrol. The decrease in translocation of reduced N into leaves was also observed in NaCl exposed plants. Inthe medium exposed to 10 mM NO,., osmotic contribution of nitrate to cumulative osmotic potential wasdecreased, and it was osmotically compensated with soluble carbohydrate. When osmotically stressed withNaC1, the contribution of chloride was much higher than that of nitrate. The present data indicate that N03-in plant tissues, factually affected by the assimilation of this ion, plays an active role in osmotic regulation incorrelation with other osmotica such carbohydrate and chloride.(Key words : Nitrate metabolism, Osmotic stress, Nitrate supply level, Osmoregulation)ate supply level, Osmoregulation)

• ETRI Journal
• /
• v.20 no.1
• /
• pp.55-73
• /
• 1998

In this paper we analyze the technological accumulation processes in the Korean semiconductor industry from the institutional approach. Institutional approach, which is closely connected with Neo-Schumpeterian tradition, has emerged as an alternative theoretical framework to neoclassical approach to understand the process of producing technological knowledge. Traditional wisdom of neoclassical approach revealed the limitation to explain the complex nature of knowledge creation and diffusion. US patent data are analyzed in terms of the increasing trend of numbers and its content to measure the rate and direction of technological capability accumulation. This analysis shows that semiconductor technologies are one of the fastest growing fields among Korean technological activities. Moreover, the analysis of patent content suggests that fabrication technologies are the most important area within the technological development of semiconductors, whilst circuit design and testing technologies are beginning to increase in significance. In addition, it is examined how private sectors and public institutions have contributed to generate technological capabilities, and the relationship between them has been changed during the development processes. It is found that Korean firms enhanced their technological capabilities from the learning and assimilation of imported technology to enhanced in-house R&D capabilities in the later stage. The support of public institution and government policy also played significant role to this successful transformation in conjunction with vigorous R&D investment of public sector.

• Korean Journal of Poultry Science
• /
• v.41 no.4
• /
• pp.313-322
• /
• 2014

Evaluation of energy in the diet is very important in animal nutrition because food intake is strongly influenced by the energy content of the diet. This means that the intake of other nutrients, such as amino acids, is affected by their ratio to energy content. Poultry can control their energy intake over a range of energy: protein ratios. Energy: protein ratio also affects the growth and body composition. Therefore we need to know what extent the relationship between energy and dietary protein influences the bird's performance. To predict the energy value of the diet or its chemical constituents, researchers have been working on modelling using the equations of the major biochemical pathways in terms of ATP generation and utilization. The activity of feeding and the metabolism caused by digestion and assimilation of food increase the animal's heat production and it can be measured by calorimetry technique. Theoretically, surplus amino acids which are not needed for protein synthesis stimulate an additional increase in metabolic rate and lead to increased energetic costs of catabolism and excretion. However, it has sometimes been shown that there was no measurable diet-induced thermoregulatory effect when an imbalanced amino acid mixture was fed. All these aspects are discussed in this review.

• Korean Medical Education Review
• /
• v.22 no.2
• /
• pp.77-84
• /
• 2020

This study introduces cognitive constructivism in reference to its emergence in the development of medical education. The main concepts of cognitive constructivism as they relate to knowledge construction and the learner's process were described, and cognitive constructivism as a learning theory was examined in its capacity to help interpret the phenomenon of medical education. Piaget's theory of cognitive constructivism and Ausubel's meaningful learning theory were applied in an attempt to explore the role of students and educators, curriculum, and teaching and learning in medical education from a cognitive constructivist perspective. When faced with new information, learners compare it with the existing schema to understand, and in order to resolve conflicts caused by inconsistencies in the information, learners incorporate assimilation and accommodation to help maintain equilibration. Therefore, instructors must meaningfully connect new content to the learner's existing schema and make endless efforts to satisfy learners' intellectual curiosity. The basic premises of medical education content is a suitable subject of meaningful learning. A learner who already possesses well-structured knowledge is likely to experience meaningful learning and a richer intellectual experience. Therefore, it is necessary to organize the curriculum strategically and elaborately so that learners can have an improved and effective learning experience.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2011.11a
• /
• pp.20-27
• /
• 2011

A system for fine-resolution long-range weather forecast is introduced in this study. The system is basically consisted of a global-scale coupled general circulation model (CGCM) and Weather Research and Forecast (WRF) regional model. The system makes use of a data assimilation method in order to reduce the initial shock or drift that occurs at the beginning of coupling due to imbalance between model dynamics and observed initial condition. The long-range predictions are produced in the system based on a non-linear ensemble method. At the same time, the model bias are eliminated by estimating the difference between hindcast model climate and observation. In this research, the predictability of the forecast system is studied, and it is illustrated that the system can be effectively used for the high resolution long-term weather prediction. Also, using the system, fine-resolution climatological data has been produced with high degree of accuracy. It is proved that the production of agrometeorological variables that are not intensively observed are also possible.

• Atmosphere
• /
• v.30 no.4
• /
• pp.319-333
• /
• 2020

Aircraft observations constitute one of the major sources of temperature observations which provide three-dimensional information. But it is well known that the aircraft temperature data have warm bias against sonde observation data, and therefore, the correction of aircraft temperature bias is important to improve the model performance. In this study, the algorithm of the bias correction modified from operational KMA (Korea Meteorological Administration) global model is adopted in the preprocessing of aircraft observations, and the effect of the bias correction of aircraft temperature is investigated by conducting the two experiments. The assimilation with the bias correction showed better consistency in the analysis-forecast cycle in terms of the differences between observations (radiosonde and GPSRO (Global Positioning System Radio Occultation)) and 6h forecast. This resulted in an improved forecasting skill level of the mid-level temperature and geopotential height in terms of the root-mean-square error. It was noted that the benefits of the correction of aircraft temperature bias was the upper-level temperature in the midlatitudes, and this affected various parameters (winds, geopotential height) via the model dynamics.

• Journal of Family Resource Management and Policy Review
• /
• v.14 no.4
• /
• pp.151-171
• /
• 2010

Multi-culturalization in our society may be the cause of many problems, but if appropriately dealt with, diversity brought on by multi-culturalization could resolve chronic abuses in education and create a new culture, thereby contributing greatly to national development. The purpose of this study was to examine the current research on multi-cultural education and to provide a normative orientation to multi-cultural education. The literature research was conducted between March 2008 and September 2009. The followings are the findings of this study. First, the results reveal that the appropriate target of a multi-cultural society should not be assimilation, but rather, multi-culturalism. Multi-culturalism has greater adaptability, and the key lies in its respect for human rights, its strengthening of multi-cultural capacity, and its consideration for the minority by moving toward corporate multi-culturalism that aims for equality in results. Second, the first form of multi-cultural education emphasizes neutrality and argues that it is the best way to respect different cultures. This form of multi-cultural education emphasizes neutrality toward "sameness." In this context, sameness means equality of the rights of human beings. The other form of multi-cultural education emphasizes diversity and argues that it is the best way to respect different cultures. It focuses on the recognition of particularity. But it reveals its shortcomings when it excludes interaction not only between an individual and the culture, but also between the insider and outsider of the culture and its social institutions. Thus, multi-cultural education for mutual understanding is suggested. Third, it has been found that pure homogeneous nationalism must be destroyed, but nationalism needs to transform itself rather than be abolished in a globalized and multi-cultural society. Moreover, on behalf of pursuing open nationalism, the self-transformation of nationalism is advisable, in order to for it to overcome its antagonistic and exclusive nature.