• Korean Journal of Remote Sensing
• /
• v.38 no.2
• /
• pp.179-188
• /
• 2022

Global warming causes climate change and increases extreme weather events worldwide, and the occurrence of heatwaves and droughts is also increasing in Korea. For the monitoring of extreme weather, various satellite data such as LST (Land Surface Temperature), TCI (Temperature Condition Index), NDVI (Normalized Difference Vegetation Index), VCI (Vegetation Condition Index), and VHI (Vegetation Health Index) have been used. VHI, the combination of TCI and VCI, represents the vegetation stress affected by meteorological factors like precipitation and temperature and is frequently used to assess droughts under climate change. TCI and VCI require historical reference values for the LST and NDVI for each date and location. So, it is complicated to produce the VHI from the recent satellite GK2A (Geostationary Korea Multi-Purpose Satellite-2A). This study examined the retrieval of VHI using GK2A AMI (Advanced Meteorological Imager) by referencing the historical data from VIIRS (Visible Infrared Imaging Radiometer Suite) NDVI and LST as a proxy data. We found a close relationship between GK2A and VIIRS data needed for the retrieval of VHI. We produced the TCI, VCI, and VHI for GK2A during 2020-2021 at intervals of 8 days and carried out the interpretations of recent extreme weather events in Korea. GK2A VHI could express the changes in vegetation stress in 2020 due to various extreme weather events such as heatwaves (in March and June) and low temperatures (in April and July), and heavy rainfall (in August), while NOAA (National Oceanic and Atmospheric Administration) VHI could not well represent such characteristics. The GK2A VHI presented in this study can be utilized to monitor the vegetation stress due to heatwaves and droughts if the historical reference values of LST and NDVI can be adjusted in a more statistically significant way in the future work.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.24 no.4
• /
• pp.267-274
• /
• 2022

The effect of year, varieties, nitrogen application, and transplant time were examined in relation to rice of protein. An experiment was conducted using 12 rice varieties to investigate the effect of management and weather conditions on brown rice protein of during the filling stage. The transplanting time was set to be three groups including early, medium, and late timing. The nitrogen application was set to be 0 N kg / 10a, 9N kg / 10a and 18 N kg / 10a to examine the effect of fertilizer management on protein content. Field experiments were conducted in three growing seasons including 2019, 2020, and 2021. The brown rice of protein content were 5.7%, 5.9%, and 6.6% under early, medium, and late transplanting time conditions, respectively. The protein content differ by variety. For example, Chucheong, Hopum, Ilpum, Mipum, Odae, Saenuri, and Saeilmi had more than 6.1%, and Chindeul, Shindongjin, Samkwang, Unkwang, Younhojinmi were less than 6.1%. Nitrogen content was 5.7% for 0kgN /10a, 6.1% for 9kgN /10a, and 6.8% for 18kgN /10a. The contribution of the characteristics to the protein content was highest in nitrogen content (38.8%), followed by transplanting time (13.7%), variety (8.2%), and year (3.5%). The average temperature for 20 days after heading time was the highest (9.3%), followed by sunshine duration (3.9%) and solar radiation (3.5%). Our results revealed that brown rice protein content was determined to be affected by changes in average temperature, sunshine duration and solar radiation for 20 days after heading time. This suggested that assessment of temperature and solar radiation after heading time would indicate the degree of rice quality in terms of protein.

• Journal of the Korean earth science society
• /
• v.43 no.6
• /
• pp.691-711
• /
• 2022

The state-of-the-art Earth system model as a virtual Earth is required for studies of current and future climate change or climate crises. This complex numerical model can account for almost all human activities and natural phenomena affecting the atmosphere of Earth. The Unified Model (UM) from the United Kingdom Meteorological Office (UK Met Office) is among the best Earth system models as a scientific tool for studying the atmosphere. However, owing to the expansive numerical integration cost and substantial output size required to maintain the UM, individual research groups have had to rely only on supercomputers. The limitations of computer resources, especially the computer environment being blocked from outside network connections, reduce the efficiency and effectiveness of conducting research using the model, as well as improving the component codes. Therefore, this study has presented detailed guidance for installing a new version of the UM on high-performance parallel computers (Linux clusters) owned by individual researchers, which would help researchers to easily work with the UM. The numerical integration performance of the UM on Linux clusters was also evaluated for two different model resolutions, namely N96L85 (1.875° ×1.25° with 85 vertical levels up to 85 km) and N48L70 (3.75° ×2.5° with 70 vertical levels up to 80 km). The one-month integration times using 256 cores for the AMIP and CMIP simulations of N96L85 resolution were 169 and 205 min, respectively. The one-month integration time for an N48L70 AMIP run using 252 cores was 33 min. Simulated results on 2-m surface temperature and precipitation intensity were compared with ERA5 re-analysis data. The spatial distributions of the simulated results were qualitatively compared to those of ERA5 in terms of spatial distribution, despite the quantitative differences caused by different resolutions and atmosphere-ocean coupling. In conclusion, this study has confirmed that UM can be successfully installed and used in high-performance Linux clusters.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.2B
• /
• pp.121-135
• /
• 2010

This study is to assess the effect of potential future climate change on the inflow of agricultural reservoir and its impact to downstream streamflow by reservoir operation for paddy irrigation water supply using the SLURP. Before the future analysis, the SLURP model was calibrated using the 6 years daily streamflow records (1998-200398 and validated using 3 years streamflow data (2004-200698 for a 366.5 $km^2$ watershed including two agricultural reservoirs (Geumgwang8 and Gosam98located in Anseongcheon watershed. The calibration and validation results showed that the model was able to simulate the daily streamflow well considering the reservoir operation for paddy irrigation and flood discharge, with a coefficient of determination and Nash-Sutcliffe efficiency ranging from s 7 to s 9 and 0.5 to s 8 respectively. Then, the future potential climate change impact was assessed using the future wthe fu data was downscaled by nge impFactor method throuih bias-correction, the future land uses wtre predicted by modified CA-Markov technique, and the future ve potentiacovfu information was predicted and considered by the linear regression bpowten mecthly NDVI from NOAA AVHRR ima ps and mecthly mean temperature. The future (2020s, 2050s and 2e 0s) reservoir inflow, the temporal changes of reservoir storaimpand its impact to downstream streamflow watershed wtre analyzed for the A2 and B2 climate change scenarios based on a base year (2005). At an annual temporal scale, the reservoir inflow and storaimpchange oue, anagricultural reservoir wtre projected to big decrease innautumnnunder all possiblmpcombinations of conditions. The future streamflow, soossmoosture and grounwater recharge decreased slightly, whtre as the evapotransporation was projected to increase largely for all possiblmpcombinations of the conditions. At last, this study was analysed contribution of weather, vegetation and land use change to assess which factor biggest impact on agricultural reservoir and stream watershed. As a result, weather change biggest impact on agricultural reservoir inflow, storage, streamflow, evapotranspiration, soil moisture and groundwater recharge.

• Korean Journal of Ecology and Environment
• /
• v.56 no.4
• /
• pp.320-329
• /
• 2023

Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg^-1 Cd, 96% at 1.87 mg kg^-1 Cd, and 93% at 6.09 mg kg^-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg^-1, 13.06 mg kg^-1, and 79.11 mg kg^-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg^-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.

• Genomics & Informatics
• /
• v.21 no.3
• /
• pp.39.1-39.15
• /
• 2023

DNA barcoding without assessing reliability and validity causes taxonomic errors of species identification, which is responsible for disruptions of their conservation and aquaculture industry. Although DNA barcoding facilitates molecular identification and phylogenetic analysis of species, its availability in clariid catfish lineage remains uncertain. In this study, DNA barcoding was developed and validated for clariid catfish. 2,970 barcode sequences from mitochondrial cytochrome c oxidase I (COI) and cytochrome b (Cytb) genes and D-loop sequences were analyzed for 37 clariid catfish species. The highest intraspecific nearest neighbor distances were 85.47%, 98.03%, and 89.10% for COI, Cytb, and D-loop sequences, respectively. This suggests that the Cytb gene is the most appropriate for identifying clariid catfish and can serve as a standard region for DNA barcoding. A positive barcoding gap between interspecific and intraspecific sequence divergence was observed in the Cytb dataset but not in the COI and D-loop datasets. Intraspecific variation was typically less than 4.4%, whereas interspecific variation was generally more than 66.9%. However, a species complex was detected in walking catfish and significant intraspecific sequence divergence was observed in North African catfish. These findings suggest the need to focus on developing a DNA barcoding system for classifying clariid catfish properly and to validate its efficacy for a wider range of clariid catfish. With an enriched database of multiple sequences from a target species and its genus, species identification can be more accurate and biodiversity assessment of the species can be facilitated.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.18 no.4
• /
• pp.117-129
• /
• 2023

Organizations must seek change in order to adapt to environmental changes and achieve better performance. However, despite this obvious statement, empirical analysis has been almost non-existent due to the difficulty of manipulating organizational performance or change. In this study, we overcame these limitations and analyzed the causes and effects of organizational change by assuming a professional sports team as a venture company, which is relatively easy to objectively measure and evaluate organizational change or performance. We systematically collected and preprocessed traditional and advanced metrics of National Basketball Association (NBA) statistics along with preprocessed trade data from eight years of regular seasons (2014~2015-2021~2022) to analyze our research model. Assessment of process macro model 7 derives the following empirical result. The results of the empirical analysis depict that NBA teams with low organizational performance in the previous season are more likely to make organizational changes through player trades to improve performance. Into the bargain player trades mediate the static relationship between the winning percentage in the previous season and the winning percentage in the current season. However, the indirect effect of a team's previous season's performance on player trades appears to vary depending on the current situations and context of each NBA team. Teams that made the playoffs in the previous season tend to make fewer trades than teams that did not and the previous season's performance is highly correlated with the current season's performance. On the other hand, teams that did not make the playoffs in the previous season tend to make a relatively larger amount of player trades in total, and the mediating effect of trades vanishes in this case. In other words, teams that did not make the playoffs in the previous season experience a larger change in performance due to trades than teams that made the playoffs, even if they achieved the same winning percentage. This empirical analysis of the inverse relationship between organizational change and the performance of professional sports teams has both theoretical and practical implications in the field of sports industry and management by analyzing the fundamentals of organizational change and the performance of professional sports teams.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.12 no.1
• /
• pp.9-23
• /
• 2007

To investigate the degree of pollution using the species composition of benthic community and environments, the present study was conducted in Jinhae Bay, May of 1998. In Jinhae Bay, benthic macrofaunal community was investigated on the base of the samples from 67 stations. The main facies of the surface sediment was silty clay and clay. The total species number and the mean density of macrobenthic animals were 255 species and 984 $ind./m^2$, respectively. There were 90 species and 773 $ind./m^2$ of polychaetes as the most major faunal group in Jinhae Bay. At the region between the eastern mouth of Jinhae Bay and Gadeok Is., the species number and density were higher, while lower at the western area of Jinhae Bay. The most dominant benthic macrofauna in Jinhae Bay was the polychaetes, Lumbrineris longifolia(16.9%), and followed by polychaetes Tharyx sp.(6.7%), Clone teres(4.7%), Glycinde sp.(4.2%), bivalves Theora fragilis(4.0%), crustaceans Corophium sp.(4.0%) and so on. The most of the predominant species appeared mainly on the region between the eastern mouth of Jinhae Bay and Gadeok Is. Cluster analysis based on the macrobenthic faunal composition showed that Jinhae Bay could be divided into three station groups: The western Jinhae Bay(Station group A), the mouth of Jinhae Bay(Station groupe B), and offshore area between Gadeok Is. and Geoje Is.(Station group C). The mouth of Jinhae Bay had the highest mean species number and the mean density, and its important species was Lumbrineris longifolia. The offshore area between Gadeok Is. and Geoje Is. had medium mean species number and the mean density. The western Jinhae Bay had the lowest mean species number and the mean density. The distribution of BPI and BC values, used to assess benthic pollution, showed similar patterns. According to the classification proposed by Borja et al.(2000), the stations of the western inner-bay were heavily polluted sites, the stations between mouth of the bay and the offshore area were slightly polluted sites, and the stations of the other area were meanly polluted sites. Benthic community healthiness of the western Jinhae Bay was classified to 'Transitional to pollution' by BC values. The degree of pollution in Jinhae Bay may have extended gradually from the western Jinhae Bay to the mouth of the bay.

• Journal of the Korean Applied Science and Technology
• /
• v.41 no.2
• /
• pp.484-497
• /
• 2024

Neonicotinoid pesticides, widely used worldwide as potent insecticides, have been found to have detrimental effects on the environment and living organisms due to their persistent residues. This study aimed to investigate the neonicotinoid pesticides, imidacloprid, and clothianidin, focusing on their impact on honey bee toxicity and foliar residue levels. Alfalfa was selected as control crop while bell peppers, and cucumbers were chosen as representative application crops, respectively. The investigation involved comparing the toxicity and foliar residue levels resulting from soil and foliar treatments, with a focus on identifying potential shortcomings in conventional foliar residue toxicity testing methods. Imidacloprid and clothianidin were applied to crops or soil at recommended rates and through irrigation. The honey bee mortality rate (RT₂₅) over time was determined, and pesticide residues on leaves were quantified using High-Performance Liquid Chromatography (HPLC). The results revealed that foliar treatment with imidacloprid on alfalfa resulted in an RT₂₅ of less than 1 day, with residues ranging from 1.07 to 19.27 mg/kg. In contrast, application on bell peppers showed RT₂₅ within 9 days, with residues ranging from 1.00 to 45.10 mg/kg. Clothianidin foliar treatment displayed RT₂₅ within 10 days on alfalfa, with residues between 0.61 and 2.57 mg/kg. On bell peppers, RT₂₅ was within 28 days, with residues ranging from 0.13 to 2.85 mg/kg. Soil treatment with imidacloprid and clothianidin in alfalfa exhibited minimal impact on honey bees and residues of 0.05 to 0.37 mg/kg. However, in applied crops, imidacloprid showed RT₂₅ within 28 days and residues ranging from 4.47 to 130.43 mg/kg, while clothianidin exhibited RT₂₅ within 35 days and residues between 5.96 and 42.32 mg/kg. In conclusion, when comparing honey bee toxicity and foliar residues among crops, application crops had a more significant impact on honey bee mortality and higher residue levels compared to control crops. Moreover, soil treatment for application crops resulted in higher RT₂₅ and residue levels compared to foliar treatment. Therefore, to ensure pesticide safety and environmental sustainability, diverse research approaches considering different crops and application methods are necessary for the safety assessment of imidacloprid and clothianidin.

• Journal of Nutrition and Health
• /
• v.57 no.1
• /
• pp.136-152
• /
• 2024

Purpose: A comprehensive evaluation item was developed to assess adolescent dietary habits and nutritional practices, considering food intake, eating behaviors, and food culture, such as social support and food environment. Methods: The 59 candidate items of the evaluation checklist were obtained based on the results of the eighth Korea National Health and Nutrition Examination Survey data, Korea Dietary Reference Intakes, dietary guidelines for adolescents, Youth Risk Behavior Survey data, national nutrition policies and dietary guidelines, and literature reviews. Four hundred and three middle and high school students residing in metropolitan areas participated in a survey using the 58-item checklist, which was selected through expert evaluation and content validity ratio analysis. The construct validity of the assessment tool for the quality of adolescent diets was assessed by exploratory factor analyses to determine if the checklist items were organized properly and whether the responses to each item were distributed adequately. Results: The Bartlett sphericity test was significant for each area (p <0.001), and the eigen values were greater than one. The Kaiser-Meyer-Olkin and cumulative proportions by areas were food intake (0.765 and 56.8%, respectively), eating behaviors (0.544 and 64.8%, respectively), and food environment (0.699 and 62.4%, respectively). Twenty-two checklists were determined for the final evaluation items for the adolescents' dietary habits and nutritional practices and were categorized into three distinct factors: food intake (10 items), eating behaviors (4 items), and food environment (8 items). Conclusion: The evaluation items for adolescent dietary habits and nutritional practices is a useful checklist for easily and quickly assessing the dietary qualities and reflecting Korean adolescents and their food environmental factors related to a sustainable diet.