• Journal of Wetlands Research
• /
• v.25 no.3
• /
• pp.205-212
• /
• 2023

This study was attempted to find out how the ecological niche and interspecies relationship of Quercus aliena and Q. serrata, which are the main constituents of potential natural vegetation along the riverside of mountains in Korea, under climate change conditions. To this end, soil moisture and soil nutrients were treated with 4 grad ients under climate change conditions with elevated CO₂ and temperature, plants we re harvested at the end of the growing season, growth responses of traits were measured, ecological niche breadth and overlap were calculated, and it was compared with that of the control group(ambient condition). In addition, the relationship between the two species was analyzed by principal component analysis using trait values. As a result, the ecological niche breadth of Q. aliena was wider than that of Q. serrata under the moisture environment conditions under climate change. Under nutrient conditions, the ecological niche of the two species were similar. In addition, the ecological overlap for soil moisture of Q. aliena and Q. serrata was wider than the soil nutrient gradient under climate change. The species with traits in which the increase in ecological niche breadth due to climate change occurred more than the decrease was Q. aliena in both water and nutrient gradients. And in the responses of the population level, due to climate change, the adaptability of Q. aliena was higher than that of Q. serrata under the soil moisture condition, but the two species were similar under the nutrient condition. These results mean that the competition between the two species occurs more severely in the water environment under climate change conditions, and at that time, Q. aliena has higher adaptability than Q. serrata.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.5
• /
• pp.417-426
• /
• 2023

Rapid climate change has resulted in glacial retreat and increased meltwater inputs in the Antarctic Peninsula, including King George Island where Marian Cove is located. Consequently, these phenomena are expected to induce changes in the water column light properties, which in turn will affect phytoplankton communities. To comprehend the effects of glacial retreat on the marine ecosystem in Marian Cove, we investigated on phytoplankton biomass (chlorophyll-a, chl-a) and various environment parameters in this area in December 2021 and January 2022. The average temperature at the euphotic depth in January 2022 (1.41 ± 0.13 ℃) was higher than that in December 2021 (0.87 ± 0.17 ℃). Contrastingly, the average salinity was lower in January 2022 (33.9 ± 0.10 psu) than in December 2021 (34.1 ± 0.12 psu). Major nutrients, including dissolved inorganic nitrogen, phosphate, and silicate, were sufficiently high, and thus, did not act as limiting factors for phytoplankton biomass. In December 2021 and January 2022, the mean chl-a concentrations were 1.03 ± 0.64 and 0.66 ± 0.15㎍ L^-1, respectively. The mean concentration of suspended particulate matter (SPM) was 24.9 ± 3.54 mgL^-1 during the study period, with elevated values observed in the vicinity of the inner glacier. However, relative lower chl-a concentrations were observed near the inner glacier, possibly due to high SPM load from the glacier, resulting in reduced light attenuation by SPM shading. Furthermore, the proportion of nanophytoplankton exceeded 70% in the inner cove, contributing to elevated mean fractions of nanophytoplankton in the glacier retreat marine ecosystem. Overall, our study indicated that freshwater and SPM inputs from glacial meltwater may possibly act as main factors controlling the dynamics of phytoplankton communities in glacier retreat areas. The findings may also serve as fundamental data for better understanding the carbon cycle in Marian Cove.

• Journal of International Area Studies (JIAS)
• /
• v.14 no.1
• /
• pp.77-106
• /
• 2010

As for the matter of guardianship-benefit network which has been at the heart of the discussion of power elites and clan politics in Kazakhstan, it has been often maintained that it is basically formed by the framework of the regional and descent connection net called Zhuz or at least it has been heavily under Zhuz's influence. But it is pointed out that the controversy of Zhuz suffers from a lot of limitations in explaining the surface of power elites in the recent process of political changes and the rearrangement of power relations. Consequently, this paper tried to take a closer look at the matter focusing on the social backgrounds of elites from Junior zhuz, who have been estimated to be relatively pushed back in terms of the advancement into the central power. As a result, it was found that the backgrounds of clan and tribe origin within Zhuz couldn't have any foundation to be seen as a decisive element through which they could grow into power elites. The phenomenon of Kazakhstani elites is a legacy of concrete historic situations. The important consideration points for analyzing the emergence of elites which could be applied to a nomadic and traditional society can hardly be an invariable framework for analyzing modern elites since independence. Since 2000, Kazakhstan has experienced economic changes including privatization due to the absolute strengthening of presidential influence which turned into a foundation for a new authoritarian system, the rearrangement of the inner circle of power, and their decisions. These changes in situations have had profound effects on the character of power elites. The phenomenon that clandestine connections have shown their appearances as they have gotten intertwined with various factors, in particular, in the economic field which has been heavily under Junior zhuz makes us convinced that the elite organization in Kazakhstan has always been the product of political and economic changes. In reality, the behaviors of elites were the outcome continuously reflecting environmental situations surrounding them, and those situations lie in a complicated and multiple-layered connection net. Therefore, it is believed that having interests in elites' social backgrounds and maintaining many pieces of information on them will be able to be a more useful approach to analyzing the elite society in the future in that interests in their social backgrounds become an informant of various network formation nets which reflect real situations.

• Economic Analysis
• /
• v.26 no.1
• /
• pp.84-132
• /
• 2020

A central bank infers market expectations of future yields based on yield curves. The central bank needs to precisely understand the changes in market expectations of future yields in order to have a more effective monetary policy. This need explains why a range of models have attempted to produce yield curves and market expectations that are as accurate as possible. Alongside the development of bond markets, the interconnectedness between them and macroeconomic factors has deepened, and this has rendered understanding of what macroeconomic variables affect yield curves even more important. However, the existence of various theories about determinants of yields inevitably means that previous studies have applied different macroeconomics variables when estimating yield curves. This indicates model uncertainties and naturally poses a question: Which model better estimates yield curves? Put differently, which variables should be applied to better estimate yield curves? This study employs the Dynamic Nelson-Siegel Model and takes the Bayesian approach to variable selection in order to ensure precision in estimating yield curves and market expectations of future yields. Bayesian variable selection may be an effective estimation method because it is expected to alleviate problems arising from a priori selection of the key variables comprising a model, and because it is a comprehensive approach that efficiently reflects model uncertainties in estimations. A comparison of Bayesian variable selection with the models of previous studies finds that the question of which macroeconomic variables are applied to a model has considerable impact on market expectations of future yields. This shows that model uncertainties exert great influence on the resultant estimates, and that it is reasonable to reflect model uncertainties in the estimation. Those implications are underscored by the superior forecasting performance of Bayesian variable selection models over those models used in previous studies. Therefore, the use of a Bayesian variable selection model is advisable in estimating yield curves and market expectations of yield curves with greater exactitude in consideration of the impact of model uncertainties on the estimation.

• Journal of the Korean Geotechnical Society
• /
• v.25 no.4
• /
• pp.91-103
• /
• 2009

Slope failure depends upon the climatic features related to related rainfall, structural geology and geomorphological features as well as the variation of the mechanical behaviors of soil constituting a slope. In this paper, among many variables, effects of soil layer thickness on the slope failure process, and variations of matric suction and volumetric water content were observed. When the soil layer is relatively thick, the descending wetting front decreases matric suction and the observed matric suction reaches to "0" value. When the wetting front reaches to the impermeable boundary, the bottom surface of steel soil box, ascending wetting front was observed. This observation can be postulated to be the effects of various sizes of pores. When macro size pores exist, the capillary effects can be reduced and infilling of pore will be limited. The partially filled pores would be filled with water during the ascending of the wetting front, which bounces from the impermeable boundary. This assumption has been assured from the observation of variation of the volumetric water contents at different depth. When the soil layer is thick (thickness = 20 cm), for granular material, erosion is a cause triggering the slope failure. It has been found that the initiation of erosion occurs when the top soil is fully saturated. Meanwhile, when the soil layer is shallow (thickness = 10 cm), slope slides as en mass. The slope failure for this condition occurs when the wetting front reaches to the interface between the soil layer and steel soil box. As the wetting front approaches to the bottom of soil layer, reduction of shear resistance along the boundary and increase of the unit weight due to the infiltration occur and these produce complex effects on the slope failure processes.

• Journal of Naturopathy
• /
• v.8 no.1
• /
• pp.29-39
• /
• 2019

Purposes: The purpose of this study was to investigate the satisfaction of each activity in the high school students (568 students) after school career education (Career and vocation, Curriculum-related career education, Special lecture related to career, Entrance exam session, Career psychology test, Internet lecture), and then to analyze the career decision-making self-efficacy of the items Goal selection, Job information, Problem solving and Future plan by high, middle, and low group. Methods: Questionnaires administered to subjects after career education counseling education. Results: Career decision - making self - efficacy was significantly higher in the high group than in the middle and low groups in the goal selection, job information, problem-solving and future planning by the educational satisfaction on career and vocation, curriculum-related lectures, entrance examination session (p<.001). The level of satisfaction of special career lectures was in the order of low group> high group> middle group in career decision self - efficacy, and the values of high and low groups were significantly higher than those of the middle group. The effect of satisfaction on career decision self - efficiency in Career psychological examination education was in the order of top> middle> low groups in goal choice and job information, and the high group values were significantly higher than the middle and low groups. In the problem solving and future planning, there was a difference between high, middle, and low group values, but there was no significant difference. The effect of the satisfaction of the internet course on the career decision self - efficacy was not significant, but there was a difference between the high, middle, and low groups. Satisfaction with the internet course was low and did not affect the decision - making self - efficacy significantly. Conclusion: The higher the satisfaction of career education, the higher self - determination efficacy of goal selection, job information, problem solving and future plan. This study suggests the direction of career education.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.25 no.2
• /
• pp.12-19
• /
• 2023

This study conducted an experiment with EC 1.0ms/cm ratio and excellent soil conditions for germination in ICT-based ginseng process cultivation. The first growth survey was conducted before transplantation of ginseng 1-year roots grown by seeding ginseng in the process cultivation, conventional cultivation and a second growth comparison survey was conducted after 3 months of growth. In the results, it was confirmed that ginseng grown in the process cultivation grew more than in the field. As a result of comparing the contents of 11 ginsenosides of 1-year and 2-year-old ginsenosides in the process cultivation and conventional cultivation ginseng, it was confirmed that the content of the process cultivation ginseng was higher than that of practice cultivation ginseng. In conclusion, conventional cultivation ginseng grows due to various factors under the natural cultivation environment, but process cultivation can secure the growth stability of ginseng by allowing stable soil and environmental control, so continuous research is needed in the future.

• Korean Journal of Plant Resources
• /
• v.36 no.4
• /
• pp.369-380
• /
• 2023

Developing and breeding improved legume-based food resources require collecting useful genetic traits with heritability even though requiring some time-consuming, costly, and labor intensive. We attempted to infer heritability of nine genetic traits-days to flowering, days to maturity, period from flowering to maturity, the number of seeds per pod, 100-seeds weight, and four contents such as crude protein, crude oil, crude fiber, and dietary fiber-using 455 homologous chloroplast gene sets of six species of legumes. Correlation analysis between genetic trait differences and phylogenetic distance of homologous gene sets revealed that days to flowering, the number of seeds per pod, and crude oil content were influenced by genetic factors rather than environmental factors by 62.86%, 69.45%, 57.14% of correlated genes (P-value ≤ 0.05) and days to maturity showed intermediate genetic effects by 62.42% (P-value ≤ 0.1). The period from flowering to maturity and 100-seeds weight showed different results compared to those of some previous studies, which may be attributed to highly complicated internal (epistatic or additive gene effects) and external effects (cultural environment and human behaviors). Despite being slightly unexpected, our results and method can widely contribute to analyze heritability by including genetic information on mitochondria, nuclear genome, and single nucleotide polymorphisms.

• Korean Journal of Environment and Ecology
• /
• v.37 no.2
• /
• pp.151-162
• /
• 2023

This study investigated the characteristics of fish communities and inhabiting status of the endangered species, Rhodeus pseudosericeus, in the Geumdang Stream in Korea from March to October 2021. A total of 1,698 fish in 5 families and 25 species were collected from 7 survey stations during the survey period. The dominant species was Zacco platypus (relative abundance, 46.5%), and the subdominant species was Squalidus gracilis majimae (16.7%), followed by Rhynchocypris oxycephalus (12.0%), Z. koreanus (5.7%), Pungtungia herzi (3.2%), R. pseudosericeus (2.0%), R. notatus (1.9%), and Acheilognathus rhombeus (1.8%). Nine Korean endemic species (36.0%) were collected, including R. pseudosericeus, R. uyekii, Sarcocheilichthys variegatus wakiyae, Microphysogobio yaluensis, S. gracilis majimae, Z. koreanus, Cobitis nalbanti, Iksookimia koreensis, and Odontobutis interrupta. An exotic species, Micropterus salmoides, designated as an invasive alien species (IAS), was collected downstream. The investigation of the habitat patterns of the endangered species (class II), Rhodeus pseudosericeus, showed a habitat range of about 6 to 7 km in the middle of Geumdang Stream (RP-1 to RP-4), and this species inhabited the edge with water depths of 0.3 through 1.0 m with slow water flow and many aquatic plants. According to the community analysis results, the overall dominance and evenness indexes were low, while diversity and richness indexes were high, and the cluster structure was largely divided into upstream and middle-downstream areas. The river health (fish assessment index) evaluated using fish was assessed as good (3 stations), normal (3 stations), and bad (1 station), and water quality was evaluated as good both upstream and downstream. Compared to previous studies, the number of species was relatively similar, and among the species that appeared in the past, 13 species did not appear in this survey, while 6 species appeared for the first time in this survey. Disturbance factors included river construction, many weirs, and the appearance of the ecosystem-disturbing species, M. salmoides. Since Geumdang Strem has high conservation value because it is home to many species in the Acheilognathinae subfamily, including the endangered species R. pseudosericeus, continuous attention and systematic conservation measures are required.

• Maritime Security
• /
• v.4 no.1
• /
• pp.1-56
• /
• 2022

Why has India become a key actor in the maritime-configured Indo-Pacific region? There are some external factors, but for India, its geo-strategic frontier encompassing its geopolitical and maritime interests is expanding rapidly beyond its territorial space across both the Indian and Pacific oceans amidst an increasingly arduous geopolitical and security environment. India must, therefore, acquire the ability to influence events within this strategic arena using all facets of national power, including maritime-military power. Lately, therefore, New Delhi has invested much intellectual capital to review its maritime-security strategy. India's new strategy is premised on the concept of holistic security involving the 'softer' aspects of maritime-security, and a rekindling of maritime consciousness in India, a nation that has traditionally been beset by 'sea-blindness'. The strategy adopts a region-wide, inclusive, and a more proactive approach than hitherto, as is evident in its title 'Ensuring Secure Seas: Indian Maritime Security Strategy'. While it deals with the growing concern of new non-traditional threats in the Indian littoral and the need for military deterrence and preparedness, it also addresses the imperatives for India to seek a favorable and rules-based benign environment in its immediate and extended maritime periphery, including through multi-vectored strategic partnerships dictated by its enduring principle of strategic autonomy. For a more profound and comprehensive understanding of India's maritime-security strategy, this paper examines the key unstated and implicit factors that underpin the strategy. These include India's historical and cultural evolution as a nation; its strategic geography; its geopolitical and security perceptions; and the political directions to its security forces. The paper deals specifically with India's response to maritime threats ranging from natural disasters, crime and state-sponsored terrorism to those posed by Pakistan and China, as well as the Indian Navy's envisaged security role East of the Malacca Straits. It also analyzes the aspects of organizational restructuring and force planning of India's maritime-security forces.