• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.721-730
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• 2021

Maritime air pollutants around port cities have gained a great deal of attention due to their direct impacts on regional air quality. This study aims to determine the geographical properties of sea/land breezes in different areas to discover overall ranges of maritime emission dispersion. The HOTMAC-RAPTAD modeling program was used to simulate regional-scale air dispersion considering non-linear and unsteady states during the general summer period for the target areas of the Yellow Sea (Incheon Port and Pyeongtaek·Dangjin Ports), archipelago region (Mokpo Port), South and East Sea (Busan and Masan Ports) and East Sea with mountainous area (Donghae·Mukho Ports). The resulting dispersion lengths of vessel emissions into the onshore regions around the target ports shed light on portal air quality management, because vessel emissions from the Incheon, Mokpo, Busan, and Donghae·Mukho ports were transported 27-31km (Western Seoul), 21-24km (Southern Muan), 20-26km (Gimhae and Yangsan), and 22-25km (Taebeak Mountains), respectively. Therefore, the results of this study provide useful data for regional air quality management and marine air pollution mitigation to improve the sustainability of port cities.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.6
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• pp.1-16
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• 2021

Global warming due to climate change is expected to significantly affect the hydrological cycle of agriculture. Therefore, in order to predict the magnitude of climate impact on agricultural water resources in the future, it is necessary to estimate the water demand for irrigation as the climate change. This study aimed at evaluating the future changes in water demand for irrigation under two Shared Socioeconomic Pathways (SSPs) (SSP2-4.5 and SSP5-8.5) scenarios for paddy rice in Gimje, South Korea. The APEX-Paddy model developed for the simulation of paddy environment was used. The model was calibrated and validated using the H₂O flux observation data by the eddy covariance system installed at the field. Sixteen General Circulation Models (GCMs) collected from the Climate Model Intercomparison Project phase 6 (CMIP6) and downscaled using Simple Quantile Mapping (SQM) were used. The future climate data obtained were subjected to APEX-Paddy model simulation to evaluate the future water demand for irrigation at the paddy field. Changes in water demand for irrigation were evaluated for Near-future-NF (2011-2040), Mid-future-MF (2041-2070), and Far-future-FF (2071-2100) by comparing with historical data (1981-2010). The result revealed that, water demand for irrigation would increase by 2.3%, 4.8%, and 7.5% for NF, MF and FF respectively under SSP2-4.5 as compared to the historical demand. Under SSP5-8.5, the water demand for irrigation will worsen by 1.6%, 5.7%, 9.7%, for NF, MF and FF respectively. The increasing water demand for irrigating paddy field into the future is due to increasing evapotranspiration resulting from rising daily mean temperatures and solar radiation under the changing climate.

• Journal of Climate Change Research
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• v.2 no.2
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• pp.79-91
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• 2011

In order to study interactions between climate change and air quality, a modeling system including the downscaling scheme has been developed in the integrated manner. This research focuses on the development of a downscaling method to utilize CCSM3 outputs as the initial and boundary conditions for the regional climate model, MM5. Horizontal/vertical interpolation was performed to convert from the latitude/longitude and hybrid-vertical coordinate for the CCSM3 model to the Lambert-Conformal Arakawa-B and sigma-vertical coordinate for the MM5 model. A variable diagnosis was made to link between different variables and their units of CCSM and MM5. To evaluate the dynamic downscaling performance of this study, spatial distributions were compared between outputs of CCSM/MM5 and NRA/MM5 and statistic analysis was conducted. Temperature and precipitation patterns of CCSM/MM5 in summer and winter showed a similar pattern with those of observation data in East Asia and the Korean Peninsula. In addition, statistical analysis presented that the agreement index (AI) is more than 0.9 and correlation coefficient about 0.9. Those results indicate that the dynamic downscaling system built in this study can be used for the research of interaction between climate change and air quality.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.405-414
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• 2021

This study predicted waxy corn harvest date in South Korea using 30-year (1991-2020) hindcasts (1-6 month lead) produced by the Pusan National University Coupled General Circulation Model (PNU CGCM)-Weather Research and Forecasting (WRF) chain. To estimate corn harvest date, the cumulative temperature is used, which accumulated the daily observed and predicted temperatures from the seeding date (5 April) to the reference temperature (1,650~2,200℃) for harvest. In terms of the mean air temperature, the hindcasts with a bias correction (20.2℃) tends to have a cold bias of about 0.1℃ for the 6 months (April to September) compared to the observation (20.3℃). The harvest date derived from bias-corrected hindcasts (DOY 187~210) well simulates one from observation (DOY 188~211), despite a slight margin of 1.1~1.3 days. The study shows the possibility of obtaining the gridded (5 km) daily temperature and corn harvest date information based on the cumulative temperature in advance for all regions of South Korea.

• Atmosphere
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• v.31 no.5
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• pp.577-592
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• 2021

This study evaluates the predictability of the number of days of heat and cold damages by growth stages of rice in South Korea using the hindcast data (1986~2020) produced by Pusan National University Coupled General Circulation Model-Weather Research and Forecasting (PNU CGCM-WRF) model chain. The predictability is accessed in terms of Root Mean Square Error (RMSE), Normalized Standardized Deviations (NSD), Hit Rate (HR) and Heidke Skill Score (HSS). For the purpose, the model predictability to produce the daily maximum and minimum temperatures, which are the variables used to define heat and cold damages for rice, are evaluated first. The result shows that most of the predictions starting the initial conditions from January to May (01RUN to 05RUN) have reasonable predictability, although it varies to some extent depending on the month at which integration starts. In particular, the ensemble average of 01RUN to 05RUN with equal weighting (ENS) has more reasonable predictability (RMSE is in the range of 1.2~2.6℃ and NSD is about 1.0) than individual RUNs. Accordingly, the regional patterns and characteristics of the predicted damages for rice due to excessive high- and low-temperatures are well captured by the model chain when compared with observation, particularly in regions where the damages occur frequently, in spite that hindcasted data somewhat overestimate the damages in terms of number of occurrence days. In ENS, the HR and HSS for heat (cold) damages in rice is in the ranges of 0.44~0.84 and 0.05~0.13 (0.58~0.81 and -0.01~0.10) by growth stage. Overall, it is concluded that the PNU CGCM-WRF chain of 01RUN~05RUN and ENS has reasonable capability to predict the heat and cold damages for rice in South Korea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.201-217
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• 2022

The United States is one of the largest producers of major crops such as wheat, maize, and soybeans, and is a major exporter of these crops. Therefore, it is important to estimate the crop production of the country in advance based on reliable long- term weather forecast information for stable crops supply and demand in Korea. The purpose of this study is to improve the seasonal predictability of the agro-climatic indices over the United States by using regional-scale daily temperature. For long-term numerical weather prediction, a dynamical downscaling is performed using Weather Research and Forecasting (WRF) model, a regional climate model. As the initial and lateral boundary conditions of WRF, the global hourly prediction data obtained from the Pusan National University Coupled General Circulation Model (PNU CGCM) are used. The integration of WRF is performed for 22 years (2000-2021) for period from June to December of each year. The empirical quantile mapping, one of the bias correction methods, is applied to the timeseries of downscaled daily mean, minimum, and maximum temperature to correct the model biases. The uncorrected and corrected datasets are referred WRF_UC and WRF_C, respectively in this study. The daily minimum (maximum) temperature obtained from WRF_UC presents warm (cold) biases over most of the United States, which can be attributed to the underestimated the low (high) temperature range. The results show that WRF_C simulates closer to the observed temperature than WRF_UC, which lead to improve the long- term predictability of the temperature- based agro-climatic indices.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.447-454
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• 2020

The purpose of this study was to determine the clinical effects of blood flow regulation exercise for improving patients' health care and its usefulness as a rehabilitation model for various diseases by analyzing and examining the existing literature. A literature review of Korean academic journals published over a 10-year period, from 2010 to 2019, was conducted using words such as "blood flow regulation," "blood flow restriction," "low-intensity exercise," and "Kaatsu." Kaatsu is a blood flow regulation exercise developed in 1966 by Dr. Yoshiaki Sato of Japan. It is an efficient and effective exercise method that uses blood flow regulation bands that increase the secretion of growth hormones to develop muscles within a short time, improves blood circulation and metabolism to prevent and improve adult diseases, shortens the rehabilitation period, and improves cardiovascular function. The study participants consisted of 10 patients, of whom four were elderly, four had obesity, one was a stroke patient, and one was a trauma patient. The results of this study show that the blood flow regulation exercise, which is a low-intensity exercise, has the same effect as high-intensity exercise, which supports the evidence that it is a highly efficient exercise method for muscle development and rehabilitation of the elderly, adolescents, and patients with injuries who have difficulty in general exercising. For future studies, further reviews are necessary to verify the effectiveness of the exercise method according to blood flow regulation site and type of disease.

• Korean Journal of Exercise Nutrition
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• v.16 no.2
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• pp.65-71
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• 2012

Oxygen is the final acceptor of electron transport from fat and carbohydrate oxidation, which is the rate-limiting factor for cellular ATP production. Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate for the shortfall caused by reduced fatty acid oxidation [1]. Therefore, training at altitude is expected to strongly influence the human metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting diabetes or related metabolic problems. However, most people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness (AMS) and insulin resistance corresponding to a increased levels of the stress hormones cortisol and catecholamine [2]. Thus, less stringent conditions were evaluated to determine whether glucose tolerance and insulin sensitivity could be improved by moderate altitude exposure (below 4000 M). In 2003, we and another group in Austria reported that short-term moderate altitude exposure plus endurance-related physical activity significantly improves glucose tolerance (not fasting glucose) in humans [3,4], which is associated with the improvement in the whole-body insulin sensitivity [5]. With daily hiking at an altitude of approximately 4000 M, glucose tolerance can still be improved but fasting glucose was slightly elevated. Individuals vary widely in their response to altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity is not apparent in those individuals with low baseline DHEA-S concentration [6]. In addition, hematopoietic adaptation against altitude hypoxia can also be impaired in individuals with low DHEA-S. In short-lived mammals like rodents, the DHEA-S level is barely detectable since their adrenal cortex does not appear to produce this steroid [7]. In this model, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can still improve insulin sensitivity, secondary to an effective suppression of adiposity [8]. Genetically obese rats exhibit hyperinsulinemia (sign of insulin resistance) with up-regulated baseline levels of AMP-activated protein kinase and AS160 phosphorylation in skeletal muscle compared to lean rats. After prolonged hypoxia training, this abnormality can be reversed concomitant with an approximately 50% increase in GLUT4 protein expression. Additionally, prolonged moderate hypoxia training results in decreased diffusion distance of muscle fiber (reduced cross-sectional area) without affecting muscle weight. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on changing body composition. Conclusion: Prolonged moderate altitude hypoxia (rangingfrom 1700 to 2400 M), but not acute high attitude hypoxia (above 4000 M), can effectively improve insulin sensitivity and glucose tolerance for humans and antagonizes the obese phenotype in animals with a genetic defect. In humans, the magnitude of the improvementvaries widely and correlates with baseline plasma DHEA-S levels. Compared to training at sea-level, training at altitude effectively decreases fat mass in parallel with increased muscle mass. This change may be associated with increased perfusion of insulin and fuel towards skeletal muscle that favors muscle competing postprandial fuel in circulation against adipose tissues.

• Korean journal of communication and information
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• v.53
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• pp.29-52
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• 2011

The purpose of this study is to explore the influence exerted by integration of newsroom upon creation, organization, and operation of news, efficiency during the process of creating news, and the qualitative level of journalism. This study has also utilized a quantitative and qualitative survey method that compares the results of survey on perception of media personnel with the results of case studies. The survey on perception is based on a questionnaire survey separately conducted on changes to organizational operation after integration among executives of top 170 newspapers in USA selected based on circulation. The details of survey include the influence of 1) Change in the system of news coverage and reporting, 2) Qualitative change to journalism, and 3) The differing backgrounds of constituent members upon operation of the integrated newsroom. Moreover, to find out whether the quantitative index shown by the perception survey is actually reflected on the media which operates an integrated newsroom, this study has conducted an in depth interview with related personnel of New York Times and Media General in USA, TMG of UK, Nordjyske of Denmark, and CBS in Korea and also engaged in literature survey. The results of the surveys are as follows. First, this study found that unlike the assertions of many earlier studies, integration of the newsroom generally exerts positive influence upon the organizational operation of a media corporation. Second, after integration, inefficiency of the past for the organization in general including coverage and reporting system, communication within and outside the organization, output of journalists, etc. decreased, and synergistic effect was created. Third, integration of the newsroom generally exercised positive influence upon enhancing the qualitative level of journalism. Fourth, while the current personnel of media generally offered positive assessment of integrating constituent members of differing backgrounds as one newsroom, the case study also showed that there are many negative aspects to it.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.2
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• pp.34-44
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• 2020

The purpose of this study was to investigate the difference in perceptions between gardens and park functions as recognized by two groups, Group A and Group B, in order to confirm the distinction between concepts and functions and then establish the importance of individual functions. The AHP was used to analyze the importance of each group's perceptions by dividing them into garden and park, Group A and non-Group A, respectively. In Group A, the importance of garden functions were considered in descending order of importance to be cultural function, ecological function, and social function. In the general group, ecological function, cultural function, and social function also appeared, but in a different order of importance. As for the park functions, Group A recognized the importance of functions in a similar order of importance to the gardens: cultural function, ecological function, and social function. Group B thought that social function, ecological function, and cultural function have the same significance. At the major classification level, Group A and Group B emphasized the social function of the parks. Group A recognized the importance of the garden's cultural function as the most important, whereas the general group emphasized the importance of the garden's ecological function. As for the mid-class level, Group A recognized the aesthetic beauty, health, ecological environment protection, and water circulation as important functions of the garden. For Group B, the ecological environment protection, aesthetic beauty, water cycle, and health were important. The concepts and functions of gardens and parks are still largely mixed but are gradually becoming differentiated. As a follow-up study, it is important to systematically manage the functions of gardens by establishing design, construction, and monitoring DB techniques for the garden type and examine the hierarchy of various other gardens.