• Korean Journal of Environment and Ecology
• /
• v.36 no.2
• /
• pp.165-176
• /
• 2022

This study surveyed the characteristics of fish communities in Hwapocheon Wetland, Korea, from May to September 2020. The survey collected 735 objects in 21 species belonging to 7 families from 8 survey stations. The dominant and subdominant species were Hemiculter eigenmanni(23.8%) and Micropterus salmoides(10.3%), respectively. The next most abundant species were Zacco platypus(9.5%), Carassius auratus(9.4%), Pseudorasbora parva(9.0%), Squalidus chankaensis tsuchigae(6.7%), Acheilognathus macropterus(5.4%), Lepomis macrochirus(5.2%), Pseudogobio esocinus(4.1%), Opsariichthys uncirostris amurensis(3.7%), and Carassius cuvieri(3.3%). Among the fish species collected, one species, Culter brevicauda, was class II endangered wildlife designated by the Ministry of Environment, and one species,S. c. tsuchigae(4.8%), was endemic to Korea.Additionally, three exotic species (M. salmoides, L. macrochirus, and C. cuvieri) and one landlocked species (Rhinogobius brunneus) were collected. Compared to previous studies, the proportion of fish living in the running water area tended to decrease, the proportion of fish living in the water purification area tended to increase, and ecosystem-disturbing species (M. salmoides and L. macrochirus) tended to increase gradually. Results of fish community analysis showed that the mainstream stations (St. 1, 3, 4, 5, 6, and 8) had low dominance, but high diversity and richness, and other stations (St. 2 and 7) had high dominance but low diversity and richness. The river health (index of biological integrity) evaluated using fish was assessed as bad (6 stations), normal (1 station), and very bad (1 station). The water quality grade was assessed as slightly bad due to the chemical oxygen demand (COD), total organic content (TOC), suspended solid (SS), and total coliforms (TC). The annual water quality showed a gradually increasing trend of biological oxygen demand (BOD), COD, SS, and chlorophyll-a. The stable life of fish and the improvement of river health in Hwapocheon Wetland require water quality improvement and the systematic management of ecosystem-disturbing species (M. salmoidesand L. macrochirus).

• Journal of Digital Convergence
• /
• v.19 no.11
• /
• pp.575-583
• /
• 2021

This study aims to analyze Taekwondo trends according to news articles by year by applying topic modeling. In order to examine the Taekwondo trend through media reports, articles including news articles and Taekwondo specialized media articles were collected through Big Kinds of the Korea Press Foundation. The search period was divided into three sections: before 2000, 2001~2010, and 2011~2020. A total of 12,124 items were selected as research data. For topic analysis, pre-processing was performed, and topic analysis was performed using the LDA algorithm. In this case, python 3 was applied for all analysis. First, as a result of analyzing the topics of media articles by year, 'World' was the most common keyword before 2000. 'South and North Korea' was next common and 'Olympic' was the third commonest topic. From 2001 to 2010, 'World' was the most common topic, followed by 'Association' and 'World Taekwondo'. From 2011 to 2020, 'World', 'Demonstration', and 'Kukkiwon' was the most common topic in that order. Second, as a result of analyzing news articles before 2000 by topic modeling, topics were divided into two categories. Specifically, Topic 1 was selected as 'South-North Korea sports exchange' and Topic 2 was selected as 'Adoption of Olympic demonstration events'. Third, as a result of analyzing news articles from 2001 to 2010 by topic modeling, three topics were selected. Topic 1 was selected as 'Taekwondo Demonstration Performance and Corruption', Topic 2 was selected as 'Muju Taekwondo Park Creation', and Topic 3 was selected as 'World Taekwondo Festival'. Fourth, as a result of analyzing news articles from 2011 to 2020 by topic modeling, three topics were selected. Topic 1 was selected as 'Successful Hosting of the 2018 Pyeongchang Winter Olympics', Topic 2 was selected as 'North-South Korea Taekwondo Joint Demonstration Performance', and Topic 3 was selected as '2017 Muju World Taekwondo Championships'.

• Korean Journal of Heritage: History & Science
• /
• v.55 no.2
• /
• pp.252-271
• /
• 2022

This article examines the characteristics of the royal tombs of the late Silla Dynasty with the statues of the 12 animal deities(Zodiac) and estimates the process of change. The features of the statues show a difference in their combination in terms of continuity and similarity of the object in their hands. In addition, there is a difference in the shape of the face of the stone statue, and differences are observed in the orientation and aspect ratio of the statue according to the sculptural method. The characteristics of these statues are somewhat different from the previously studied protected-stone and manufacturing techniques. For example, the Zodiac statues that are flattened from high relief to low relief are known to be decorated in realistic expressions, but they tend to be treated as separate conditions because they do not match the change of the stone. In addition, there was a characteristic that did not show regular changes, such as appearing and disappearing again when there was no balustrade in the tomb. Summing up the characteristics of each part, the Zodiac statues are largely divided into curved angles and flat angles according to the sculptural technique, and the head orientation and clothing of the statue are related. They are divided into two categories and can be viewed as having temporality according to the aspect ratio. These characteristic changes are consistent with the continuity of features and changes in the object in the hands of the 12 Zodiac statues. Therefore, the number of faces with protected-stone changes were gradually increasing in trend. As a result, there is a possibility that the Gujeongdong Square-shape Tomb and King Jindeok Tomb are earlier royal tombs than the Wonseong Royal Tomb. Therefore, the royal tombs of the late Silla Dynasty have a complete, tomb structure, containing the 12 animal god statues, ceremonial spaces(拜禮空間), Shindo(神道), stone statues(石像), and tombstones. This can be understood as a basic motif for the royal tomb structures of Goryeo and Joseon.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.24 no.1
• /
• pp.13-34
• /
• 2022

Soil moisture data have been collected at 11 agrometeorological stations operated by The Korea Meteorological Administration (KMA). This study aimed to verify the accuracy of soil moisture data of KMA and develop a correction formula to be applied to improve their quality. The soil of the observation field was sampled to analyze its physical properties that affect soil water content. Soil texture was classified to be sandy loam and loamy sand at most sites. The bulk density of the soil samples was about 1.5 g/cm³ on average. The content of silt and clay was also closely related to bulk density and water holding capacity. The EnviroSCAN model, which was used as a reference sensor, was calibrated using the self-manufactured "reference soil moisture observation system". Comparison between the calibrated reference sensor and the field sensor of KMA was conducted at least three times at each of the 11 sites. Overall, the trend of fluctuations over time in the measured values of the two sensors appeared similar. Still, there were sites where the latter had relatively lower soil moisture values than the former. A linear correction formula was derived for each site and depth using the range and average of the observed data for the given period. This correction formula resulted in an improvement in agreement between sensor values at the Suwon site. In addition, the detailed approach was developed to estimate the correction value for the period in which a correction formula was not calculated. In summary, the correction of soil moisture data at a regular time interval, e.g., twice a year, would be recommended for all observation sites to improve the quality of soil moisture observation data.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.42 no.2
• /
• pp.79-88
• /
• 2022

This study was conducted to evaluate the productivity of whole crop silage wheat utilizing the paddy fields during a couple of years from 2019 to 2021 in Suwon, Korea. This investigation was used the two maturity types of wheat cultivar 'Cheongwoo' (early) and 'Taeu' (late). The heading date of 2^nd year (Oct. 2020 to May. 2021) cultivation was delayed about 11 to 13 days by more than 1^st year (Oct. 2019 to May. 2020). The growth characteristics were shown that the plant height was increased in 2^nd cultivation, while the number of culms and the panicle part ratio were decreased. Moreover, the nutritive value of 'Cheongwoo' and 'Taeu' were also decreased in 2^nd cultivation. These changes have thought to a difference of the precipitation by cultivation years. Because, the precipitation during the period from the end of winter dormancy to the harvesting stage in 2^nd (337 mm) cultivation was more about twice than 1st (169.3 mm) cultivation. However, the dry matter yield of 'Cheongwoo' was not shown a statistical difference by cultivation years, while 'Taeu' was shown to decrease tendency. The total dry matter yield regardless of the cultivation years were higher in 'Cheongwoo' than 'Taeu', and especially 'Cheongwoo' was more 3 tons per hectare (15.3 t/ha) than 'Taeu' (12.6 t/ha) at 2^nd cultivation (p<0.01). The trend of dry weight in 'Cheongwoo', early mature type, showed a relatively high ratio of dry matter (p<0.05) was considered that due to a high panicle ratio by a fast heading and an adequate weight of panicles by a sufficient maturing. In conclusion, selecting the early maturity cultivars could achieve a higher and more stable total dry matter yield considering the cropping system in the central region. Furthermore, it also has the advantage of being able to double-cropping system with forage rice, which has considered the maximum whole-crop forage production year-round. These results suggest that the 'Cheongwoo' be optimum cultivar to produce the year-round forage on paddy fields in the central region.

• Korean Journal of Poultry Science
• /
• v.49 no.2
• /
• pp.115-124
• /
• 2022

The objective of this study was to investigate the effects of dietary coenzyme Q10 (CoQ10) sources on the antioxidant defense system in the blood and liver of laying hens. Thirty-six 40-wk old Lohmann Brown hens were randomly assigned to three groups based on body weight, with four cages with three layers each. Laying hens were divided into one of the following groups: control (CON), powdered CoQ10 (PCoQ, 100 mg/kg diet), and emulsified CoQ10 (ECoQ, 100 mg/kg diet). All hens were fed a control diet or a control diet supplemented with powdered or emulsified CoQ10 ad libitum for five weeks. There were no differences in body weight, weight gain, and organ weights among the treatment groups, including the liver and spleen. The blood total antioxidant power (TAP) in the ECoQ group increased (P<0.05) by approximately 2-fold compared to that in the CON group. However, there was no significant difference in blood TAP levels between the PCoQ and ECoQ groups, although a decreasing trend (P<0.13) was observed for levels of TAP in the ECoQ group. The mRNA expression and specific activities of superoxide dismutase, glutathione peroxidase, and catalase in the liver were not affected by dietary CoQ10 or type of CoQ10. However, hepatic lipid peroxidation in the ECoQ group was lower (P<0.05) than in the CON group. In conclusion, emulsified CoQ10 increased blood TAP and decreased hepatic lipid peroxidation without affecting antioxidant enzymes, suggesting that emulsified CoQ10 might be more applicable as an active antioxidant supplement than powdered type in laying hens.

• Korean Chemical Engineering Research
• /
• v.60 no.4
• /
• pp.606-612
• /
• 2022

Relatively high indoor CO₂ concentration (>1,000 ppm) has a negative impact on human health. In this work, indoor CO₂ adsorbent was developed by impregnating KOH or K₂CO₃ on commercial activated carbon, named as KOH/AC and K₂CO₃/AC. Commercial activated carbon (AC) showed relatively high BET surface area (929 m²/g) whereas KOH/AC and K₂CO₃/AC presented lower BET surface area of 13.6 m²/g and 289 m²/g. Two experimental methods of TGA (2,000 ppmCO₂, weight basis) and chamber test (initial concentration: 2,000 ppmCO₂, CO₂ IR analyzer) were used to investigate the adsorption capacity. KOH/AC and K₂CO₃/AC exhibited similar adsorption capacities (145~150 mg_CO2/g), higher than K₂CO₃/Al+Si supports adsorbent (84.1 mg_CO2/g_sample). Similarly, chamber test also showed similar trend. Both KOH/AC and K₂CO₃/AC represented higher adsorption capacities (KOH/AC: 93.5 mg_CO2/g K₂CO₃/AC: 94.5 mg_CO2/g_sample) K₂CO₃/Al+Si supports. This is due to the KOH or K₂CO₃ impregnation increased alkaline active sites (chemical adsorption), which is beneficial for CO₂ adsorption. In addition, the regeneration test results showed both K-based adsorbents pose a good regeneration and reusability. Finally, the current study suggested that both KOH/AC and K₂CO₃/AC have a great potential to be used as CO₂ adsorbent for indoor CO₂ adsorption.

• Journal of Popular Narrative
• /
• v.26 no.2
• /
• pp.251-276
• /
• 2020

The purpose of this article is to critically read Globalizing Borderlands Studies in Europe and North America to examine trends in border studies conducted so far in Europe and North America and to discuss the expandability and limitations of the narrative. It introduces a variety of case studies covering the borderlands of Europe and North America from ancient to modern times. It consists of a total of 10 chapters, in addition to the introduction chapter to clarify the purpose and definition of the collaboration and the short conclusion chapter on the prospects for the future of borderlands studies. This volume has some important implications for current borderland research in two main respects. First, it can introduce us we the areas and targets that the leading researchers from European and North American academia (usually the United States') have paid attention to. It also examines the current status of borderland research and predicts whether it will be possible to study various border areas where exist in other regions (especially in Asia) based on accumulating academic achievements, as well as the possibility of expansion of so-called 'globalization'. Second, it introduces the borderland as a conceptual space, beyond the border area as a physical space that is commonly thought of when it comes to 'border'. Cases of "conceptual borderlands" can be applied to a number of topics ranging from an individual's identities to the methods of governance, religions, economies, social institutions, families, labor issues, public health services and gender issues. There are, however, also some questions to be noted in the volume: the lack of consistent use of terminology, which can be considered general problems of collaboration studies; the fact that the authors still tend to understand borderlands within the imperialist discourse, perhaps because of their academic background is situated mainly in Europe and North America; the borderlands cases described here as the areas of conflict and struggle only. Nevertheless, the book is of significance in that it suggests a possibility of various borderlands studies and helps us to have better understanding of the current geopolitical situation imposed on the Korean Peninsula, which is located on the borderland between the continental and maritime powers.

• Journal of Conservation Science
• /
• v.37 no.6
• /
• pp.689-700
• /
• 2021

This study aims to optimize the measurement conditions of handmade Hanji paper to reduce the time required for measurement while meeting folding endurance standards, for various basis weights. Thirteen types were selected, including 12 types of Hanji with grammages of 17 g/m², 30 g/m², and 45 g/m², and one type of 75 g/m² copy paper, and 24 sheets were prepared in the laid and chain directions. Subsequently, folding endurance experiments at different load (14.72 N, 9.81 N, 4.91 N) and specimen width conditions (15 mm, 10 mm, 5 mm) were performed, using a 4-MIT folding endurance tester. The results showed that, for specimen widths of 15 mm and 10 mm under a load of 4.91 N, the folding endurance falls within the reference range (10~10000 times). In particular, reduced folding endurance range and measurement time were observed at a width of 10 mm under a load of 4.91 N. Moreover, the endurance trend lines based on the average values of load and specimen width ranges enabled the prediction of the folding endurance within those ranges, according to the decreasing slope. Furthermore, for a specimen width of 15 mm under a load of 4.91 N, the folding endurance in the comparison group (35 to 17723 times) significantly exceeds the upper limit of the reference range (10~10000 times). Therefore, the measurement conditions of 4.91 N with a specimen width of 10 mm are proposed.

• Journal of The Korean Association For Science Education
• /
• v.42 no.1
• /
• pp.127-147
• /
• 2022

Pre-service science teacher education is important to elaborate the quality of science teaching and learning in schools. Therefore, many pre-service science teacher education researches have been done in Korea. However, almost no research has comprehensively reviewed those literatures including secondary teacher education context. This study reviewed 410 pre-service science teacher education researches in Korea, from 1995 to 2021 published by 17 journals in KCI. The trends were analyzed with respect to the number of article according to period, keyword frequency, and qualitative features. The qualitative features were coded in multiple aspects of pre-service teachers' type, major, subject-matter in research context, research approach, data type, and the number of participants. The results indicate that the number of research articles has increased by about 40 for every 5-year period. JKASE has published most articles, and the diversity of journals has increased since 2010. Keyword frequency revealed that scientific concepts, science teaching efficacy, nature of science, and other teaching and learning contexts were emphasized. In qualitative features, the most frequent pre-service type was secondary in 'general' science context. For research topic, 'pre-service teacher education program' and 'perception and cognitive domain' were the most frequent. Most of the articles have 'analyzed' the phenomena or consequence of educational issue. Most research was conducted with 11 to 30 participants. These patterns of qualitative features have differed according to period, and types of pre-service teacher. Suggestions for the future pre-service science teacher education research topic were explored, such as policy-administrative research, integrated science teacher education, teacher agency, and environmental education.