• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.240-249
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• 2022

Measuring chlorophyll fluorescence (CF) is a useful tool for assessing a plant's ability to tolerate abiotic stresses such as drought, waterlogging and high temperature. Korean ginseng is highly sensitive to water stress in paddy fields. To evaluate the possibility of non-destructively diagnosing waterlogging stress using chlorophyll fluorescence (CF) imaging techniques, we screened 57 ginseng accessions for waterlogging tolerance. To evaluate waterlogging tolerance among the 2-year-old Korean ginseng accessions, we treated ginseng plants with water stress for 25 days. The physiological disorder rate was characterized through visual assessment (an assigned score of 0-5). The physiological disorder rates of Geumjin, Geumsun and GS00-58 were lower than that of other accessions. In contrast, lines GS97-62, GS97-69 and GS98-1-5 were deemed susceptible. Root traits, chlorophyll content and the reduction rates decreased in most ginseng accessions. Further, these metrics were significantly lower in susceptible genotypes compared to resistant ones. All CF parameters showed a positive or negative response to waterlogging stress, and this response continuously increased over the treatment time among the genotypes. The CF parameter Fv/Fm was used to screen the 57 accessions, and the results showed clear differences in Fv/Fm between the susceptible and resistant genotypes. Susceptible genotypes had an especially low Fv/Fm value of less than 0.8, reflecting damage to the reaction center of photosystem II. It is concluded that Fv/Fm can be used as a CF parameter index for screening waterlogging stress tolerance in ginseng genotypes.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.211-220
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• 2022

Poultry are exposed to extremely high levels of oxidative stress as a consequence of the excessive production of reactive oxygen species (ROS) induced by endogenous and exogenous stressors, such as high-stocking densities, thermal stress, environmental and feed contamination, along with factors associated with intensive breeding systems. Oxidative stress promotes lipid peroxidation, DNA damage, and inflammation, which can have detrimental effects on the health of birds. During the course of evolution, birds have developed antioxidant defense mechanisms that contribute to maintaining homeostasis when exposed to endogenous and exogenous stressors. The primary antioxidant defense systems are enzymatic and non-enzymatic in nature and play roles in protecting cells from ROS attack. Recently, plant flavonoids, which have been established to reduce oxidative stress, have been attracting considerable attention as potential feed additives. Flavonoids are a group of polyphenolic compounds that can be stabilized by binding structural compounds with ROS, and can promote the elimination of ROS by inducing the expression of antioxidant enzymes. However, although flavonoids can contribute to reducing lipid peroxidation and thereby enhance the antioxidant capacity of birds, they have low solubility in the gastrointestinal tract, and consequently, it is necessary to develop a delivery technology that can facilitate the effect intestinal absorption of these compounds. Furthermore, it is important to determine the dietary levels of flavonoids by assessing the exact antioxidant effects in the gastrointestinal tract wherein the concentrations of dietary flavonoids are highest. It is also necessary to examine the expression of transcriptional factors and vitagenes associated with the efficient antioxidant effects induced by flavonoids. It is anticipated that the application of flavonoids as natural antioxidants will become a particularly important field in the poultry industry.

• Maritime Security
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• v.4 no.1
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• pp.57-82
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• 2022

The objective of this treatise is to explore the limitations of the current navy manpower utilization system and the ways to improve it from the perspective of Generation Z. As Generation Z, following Millennials, has finally come of age, this new group is constituting a gradually greater proportion of military personnel. Due to the typical characteristics of naval operations, the harmony between Millennials and Generation Z, which is differentiated from Generation X in view of dispositions and traits, is one of the essential issues to be discussed. Generally, in a naval vessel, there are numerous pieces of equipment necessary to carry out a wide range of missions and a large number of crew members who operate them with consistent levels of fighting power. This is all while members are living together within the narrow space throughout the 24 hours of each day. Under such particular circumstances, any inter-generational conflicts may have a disruptive effect on the successful accomplishment of naval missions. Currently, new generations of military personnel are facing social difficulties in different aspects compared with the previous generations, and also have different viewpoints on the military. In this regard, in order to foster true harmony between generations, it is considered necessary to take a closer look at the inter-generational differences from their respective standpoints and to examine whether the military organization has taken adequate steps to respond to such changes. Accordingly, Chapters 1 and 2 cover the environments in which Millennials and Generation Z were raised during their childhood to young adulthood, which are distinct from those of older generations, their viewpoints formed based on such backgrounds, and the need to resolve various conflicts between generations. In Chapter 3, the current actions taken by overseas military powers to enhance the coexistence with Generation MZ are analyzed to find the significant implications they had. Chapter 4 examines the operation environments specific to the navy; identifies the potential barriers to achieving harmony between generations by assessing the current status of personnel utilization in the Korean navy in terms of the seaman, petty officer, and the officer, as well as policy; and outlines the solutions to drive harmony. Finally, Chapter 5 emphasizes the need to establish a genuine empathy between generations based on the understanding of unique inter-generational characteristics. This section also discusses the importance of addressing difficulties in utilizing technology-centered naval manpower, and forecasts a scenario of a naval organization that resolves the problem of utilizing naval personnel and the inter-generational conflicts in the future.

• Korean Journal of School Psychology
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• v.17 no.3
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• pp.401-419
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• 2020

The purpose of this study was to validate the Korean Implementation Fidelity Checklist of Tier 1 School-Wide Positive Behavior Support (KIFC-T1) for use in the Korean educational system. Tier 1 support, which is universal supports, within a multi-tiered, school-wide positive behavior support (SWPBS) model, aims to provide support to and prevent problem behaviors among all students in a school. The initial KIFC-T1 consisted of 48 items and 11 factors and was developed based on a literature review. Its content was validated by experts. The validated KIFC-T1 was introduced to 185 special school teachers who had experience implementing SWPBS and who used the instrument to assess the degree to which their schools had implemented Tier 1 support. Based on their responses, the construct validity of the KIFC-T1 was examined using factor, item, and internal consistency reliability analyses. The concurrent validity of the tool was examined using the PBS Evaluation Tool, School Climate Questionnaire, School Discipline Practice Scale, and PBS Effectiveness Scale. The analyses revealed that KIFC-T1 had a stable five-factor structure with 35 items, had good reliability (Cronbach's α=.956, each factor's Cronbach's α=.834-.951), and its results were statistically significantly correlated with those of the PBS Evaluation Tool, School Discipline Practice Scale, and the PBS Effectiveness Scale. However the KIFC-T1's results were not statistically significantly correlated with the results of the School Climate Questionnaire. These results suggest that KIFC-T1 is a reliable and valid tool for assessing the fidelity of universal support implementations.

• Atmosphere
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• v.32 no.2
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• pp.87-101
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• 2022

In this paper, the performance improvement for the new KMA's Climate Prediction System (GloSea6), which has been built and tested in 2021, is presented by assessing the bias distribution of basic variables from 24 years of GloSea6 hindcasts. Along with the upgrade from GloSea5 to GloSea6, the performance of GloSea6 can be regarded as notable in many respects: improvements in (i) negative bias of geopotential height over the tropical and mid-latitude troposphere and over polar stratosphere in boreal summer; (ii) cold bias of tropospheric temperature; (iii) underestimation of mid-latitude jets; (iv) dry bias in the lower troposphere; (v) cold tongue bias in the equatorial SST and the warm bias of Southern Ocean, suggesting the potential of improvements to the major climate variability in GloSea6. The warm surface temperature in the northern hemisphere continent in summer is eliminated by using CDF-matched soil-moisture initials. However, the cold bias in high latitude snow-covered area in winter still needs to be improved in the future. The intensification of the westerly winds of the summer Asian monsoon and the weakening of the northwest Pacific high, which are considered to be major errors in the GloSea system, had not been significantly improved. However, both the use of increased number of ensembles and the initial conditions at the closest initial dates reveals possibility to improve these biases. It is also noted that the effect of ensemble expansion mainly contributes to the improvement of annual variability over high latitudes and polar regions.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.192-212
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• 2022

The purpose of this study is to analyze scientific attitude and its components in the general remarks and in the particulars of one government-designated and seven authorized elementary school science teacher's guides for the 3rd~4th grades which were developed according to the 2015 national science curriculum, and to derive implications for future development of teacher's guide. The results of the study are as follows: First, in their general remarks, five of eight teacher's guides (62.5%) give a very brief explanation on the components of scientific attitude, and the remaining three teacher's guides give a relatively detailed explanation on the components but they lack practical information on teaching and assessing of the components; Second, in the case of unit objective in the four units of the area of 'Earth and Universe', five of eight teacher's guides (62.5%) contain 3~4 components among 'curiosity', 'cooperation', 'objectivity', 'critical mindedness', or 'respect for evidence', and one of the remaining three teacher's guides contains only the component of 'curiosity', another guide doesn't have any component, and the other guide doesn't have unit objective itself; Third, in the case of unit assessment, only one of eight teacher's guide (12.5%) has independent unit assessment, includes several components of scientific attitude in the unit assessment, and is broadly consistent between the components of scientific attitude in unit objective and in unit assessment; Fourth, in case of lesson objective, three teacher's guide (37.5%) contain 3~4 components among 'curiosity', 'cooperation', 'objectivity' and 'critical mindedness', and the remaining five teacher's guide (62.5%) include only 'curiosity'; Fifth, in the case of lesson assessment, among eight teacher's guides, five (62.5%) evaluate 3~4 components of scientific attitudes, two (25.0%) evaluate only 'curiosity' and 'cooperation', and one (12.5%) does not evaluate anything.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.274-284
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• 2022

Through sample-size-based rarefaction analyses, we tried to suggest the appropriate degree of sample concentration and sub-sample extraction, as a way to estimate more accurate zooplankton species diversity when assessing biodiversity. When we collected zooplankton from three reservoirs with different environmental characteristics, the estimated species richness (S) and Shannon's H' values showed different changing patterns according to the amount of sub-sample extracted from the whole sample by reservoir. However, consequently, their zooplankton diversity indices were estimated the highest values when analyzed by extracting the largest amount of sub-sample. As a result of rarefaction analysis about sample coverage, in the case of deep eutrophic reservoir (Juam) with high zooplankton species and individual numbers, it was analyzed that 99.8% of the whole samples were represented by only 1 mL of sub-sample based on 100 mL of concentrated samples. On the other hand, in Soyang reservoir, which showed very small species and individual numbers, a relatively low representation at 97% when 10 mL of sub-sample was extracted from the same amount of concentrated sample. As such, the representation of sub-sample for the whole zooplankton sample varies depending on the individual density in the sample collected from the field. If the degree of concentration of samples and the amount of sub-sample extraction are adjusted according to the collected individual density, it is believed that errors that occur when comparing the number of species and diversity indices among different water bodies can be minimized.

• Korean Journal of Environment and Ecology
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• v.37 no.4
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• pp.289-301
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• 2023

Forests within watersheds are essential in maintaining ecosystems and are the central infrastructure for constructing an ecological network system. However, due to indiscriminate development projects carried out over past decades, forest fragmentation and land use changes have accelerated, and their original functions have been lost. Since a forest's structural pattern directly impacts ecological processes and functions in understanding forest ecosystems, identifying and analyzing change patterns is essential. Therefore, this study analyzed structural changes in the forest landscape according to the time-series land cover changes using the FRAGSTATS model for the dam watershed of the Geum River upstream. Land cover changes in the dam watershed of the Geum River upstream through land cover change detection showed an increase of 33.12 square kilometers (0.62%) of forests and 67.26 square kilometers (1.26%) of urbanized dry areas and a decrease of 148.25 square kilometers (2.79%) in agricultural areas from the 1980s to the 2010s. The results of no-sampling forest landscape analysis within the watershed indicated landscape percentage (PLAND), area-weighted proximity index (CONTIG_AM), average central area (CORE_MN), and adjacency index (PLADJ) increased, and the number of patches (NP), landscape shape index (LSI), and cohesion index (COHESION) decreased. Identification of structural change patterns through a moving window analysis showed the forest landscape in Sangju City, Gyeongsangbuk Province, Boeun County in Chungcheongbuk Province, and Jinan Province in Jeollabuk Province was relatively well preserved, but fragmentation was ongoing at the border between Okcheon County in Chungcheongbuk Province, Yeongdong and Geumsan Counties in Chungcheongnam Province, and the forest landscape in areas adjacent to Muju and Jangsu Counties in Jeollabuk Province. The results indicate that it is necessary to establish afforestation projects for fragmented areas when preparing a future regional forest management strategy. This study derived areas where fragmentation of forest landscapes is expected and the results may be used as basic data for assessing the health of watershed forests and establishing management plans.

• Korean Journal of Environmental Biology
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• v.41 no.1
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• pp.18-30
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• 2023

Forest destruction is an inevitable result of the development processes. According to the environmental impact assessment, over 10% of the destroyed trees need to be recycled and transplanted to minimize the impact of forest destruction. However, the rate of successful transplantation is low, leading to a high rate of tree death. This is attributable to a lack of consideration for environmental factors when choosing a temporary site for transplantation and inadequate management. To monitor transplanted trees, a field survey is essential; however, the spatio-temporal aspect is limited. This study evaluated the applicability of remote sensing for the effective monitoring of transplanted trees. Vegetation indices based on satellite remote sensing were derived to detect time-series changes in the status of the transplanted trees at three temporary transplantation sites. The mortality rate and vitality of transplanted trees before and after the transplant have a similar tendency to the changes in the vegetation indicators. The findings of this study showed that vegetation indices increased after transplantation of trees and decreased as the death rate increased and vitality decreased over time. This study presents a method for assessing newly transplanted trees using satellite images. The approach of utilizing satellite photos and the vegetation index is expected to detect changes in trees that have been transplanted across the country and help to manage tree transplantation for the environmental impact assessment.

• Korean Journal of Remote Sensing
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• v.39 no.3
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• pp.325-338
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• 2023

Korean fir (Abies koreana Wilson) is one of the most important environmental indicator tree species for assessing climate change impacts on coniferous forests in the Korean Peninsula. However, due to the nature of alpine and subalpine regions, it is difficult to conduct regular field surveys of Korean fir, which is mainly distributed in regions with altitudes greater than 1,000 m. Therefore, this study analyzed the vegetation change trend of Korean fir using regularly observed remote sensing data. Specifically, normalized difference vegetation index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS), land surface temperature (LST), and precipitation data from Global Precipitation Measurement (GPM) Integrated Multi-satellitE Retrievalsfor GPM from September 2003 to 2020 for Hallasan and Jirisan were used to analyze vegetation changes and their association with environmental variables. We identified a decrease in NDVI in 2020 compared to 2003 for both sites. Based on the NDVI difference maps, areas for healthy vegetation and high mortality of Korean fir were selected. Long-term NDVI time-series analysis demonstrated that both Hallasan and Jirisan had a decrease in NDVI at the high mortality areas (Hallasan: -0.46, Jirisan: -0.43). Furthermore, when analyzing the long-term fluctuations of Korean fir vegetation through the Hodrick-Prescott filter-applied NDVI, LST, and precipitation, the NDVI difference between the Korean fir healthy vegetation and high mortality sitesincreased with the increasing LST and decreasing precipitation in Hallasan. Thissuggests that the increase in LST and the decrease in precipitation contribute to the decline of Korean fir in Hallasan. In contrast, Jirisan confirmed a long-term trend of declining NDVI in the areas of Korean fir mortality but did not find a significant correlation between the changes in NDVI and environmental variables (LST and precipitation). Further analyses of environmental factors, such as soil moisture, insolation, and wind that have been identified to be related to Korean fir habitats in previous studies should be conducted. This study demonstrated the feasibility of using satellite data for long-term monitoring of Korean fir ecosystems and investigating their changes in conjunction with environmental conditions. Thisstudy provided the potential forsatellite-based monitoring to improve our understanding of the ecology of Korean fir.