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Comparison of Seedling Quality of Cucumber Seedlings and Growth and Production after Transplanting according to Differences in Seedling Production Systems (육묘 생산 시스템 차이에 따른 오이 모종의 묘소질과 정식 후 생육 비교)

  • Soon Jae Hyeon;Hwi Chan Yang;Young Ho Kim;Yun Hyeong Bae;Dong Cheol Jang
    • Journal of Bio-Environment Control
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    • v.33 no.2
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    • pp.88-98
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    • 2024
  • This study provides basic data on the growth and production of seedlings produced in plant factories with artificial lighting by comparing seedling quality, growth and fruit characteristics, and production after transplanting cucumber seedlings according to environmental differences between plant factories with artificial lighting and conventional nurseries in greenhouse. The control group consisted of greenhouse seedlings (GH) grown in the conventional nursery before transplanting. Plant factory to greenhouse seedlings (PG) were grown for 9 days in a plant factory with artificial lighting and for 13 days in an conventional nursery. Plant factory seedlings (PF) were grown in a plant factory with artificial lighting for 22 days until planting. In terms of seedling quality, PFs had the highest relative growth rate and compactness and the best root zone development. After transplanting PFs tended to grow faster, the first harvest date was 2 days earlier than that of GHs, and the growing season ended 1 day earlier. The female flower flowering rate of the PFs was high, and the fruit set rate was of PF the lowest. The production per unit area was highest for PFs at 10.23kg Performance index on the absorption basis, the most sensitive chlorophyll fluorescence parameter, was highest at 4.14 for PFs at 4 weeks after transplantation. By comparing the maximum quantum yield of primary PS II photochemistry and dissipated energy flux per PS II reaction center electron at 4 weeks after transplantation, PFs tended to be the least stressed. PFs had the best seedling quality, growth, and production after planting, and fruit quality was consistent with that of greenhouse seedlings. Therefore, plant factory seedlings can be used in the field.

Productivity Evaluation of Rosemary Shoots using Artificial Light Sources in Multi-layer Cultivation (다단재배에서 인공광원을 이용한 로즈마리 어린순의 생산성 평가)

  • Myeong Suk Kim;Jung Seob Moon;Song Hee Ahn;Dong Chun Cheong;Min Sil Ahn;So Ra Choi
    • Journal of Bio-Environment Control
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    • v.33 no.3
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    • pp.163-171
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    • 2024
  • This study was aimed to investigate the effects of layer-by-floor environmental conditions and lower shelf supplemental lighting on the productivity of fresh shoots when growing rosemary in multi-layer cultivation. The 10-cm cuttings from stock plants of common rosemary (Rosemarinus officinalis) were planted in a 128-hole tray, rooted, and then transplanted into pots of 750, 1,300, and 2,000 mL. Afterwards, they were placed on multi-layer shelves (width × length × height: 149 × 60 × 57 cm, 3-layer) in a two-linked greenhouse and cultivated using the sub-irrigation. The productivity of young shoots by layer of the multi-layer shelf was the highest on the third floor (top floor), but productivity decreased sharply after September due to stem lignification caused by excessive light during the summer. Conversely, the lower two layers exhibited faster growth rate of young shoots until the late cultivation period, but the quality decreased due to stem softening and leaf epinasty. To address the excessive light problem on the third floor during the summer, shading was implemented at 30% opacity in July and August, resulting in a 210% increase in rosemary young shoots count and a 162% increase in fresh weight per unit area compared to the unshaded control. To improve the lighting deficiency on the lower layer, supplemental lighting with LED at 30 W increased rosemary young shoot harvest by 168% from June to September compared to no supplemental lighting, but it decreased productivity after September. Therefore, when growing rosemary in multi-layer, it is judged that intensive production of young shoots is possible if the third floor (top layer) is shaded with 30% of light from July to August to prevent stem lignification, and the lower layer is temporarily supplemented with LED 30 W from June to September to increase young shoot growth.

The Effect of Empathy Value of Chinese Female University Students on Affection with Sustainable Fashion Products on Affection and Purchase Intention (중국 여대생의 지속가능한 패션제품에 대한 공감가치가 호감도와 구매의사에 미치는 영향)

  • Yi-Fei Wu;Young-Sook Lee
    • Journal of Internet of Things and Convergence
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    • v.10 no.3
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    • pp.35-48
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    • 2024
  • This study analyzed the value empathy of environmentally sustainable fashion products, encompassing environmental, economic, and social values, drawing from existing literature. We sought to verify the relationship between empathic value and the likability and purchase intention towards these products. To validate these relationships, we formulated research hypotheses and conducted an online survey targeting female college students residing in Guangzhou, Guangdong Province, China, who have experience purchasing environmentally sustainable fashion products. The survey was conducted from August 10th to August 20th, 2023, with a total distribution of 352 questionnaires. Among the collected responses, 313 valid responses were utilized for data analysis. The collected survey data underwent frequency analysis, exploratory factor analysis, reliability and validity analysis, correlation analysis, and multiple regression analysis using SPSS 26.0 software. The analysis yielded the following results. First, the empathy value of environmentally sustainable fashion products was classified into environmental protection values, economic values, and social values. Second, the economic and social values of environmentally sustainable fashion products were found to have a positive effect on favorability. Third, it was found that the environmental protection value and social value of environmentally sustainable fashion products had a positive effect on purchase intention. Fourth, it was found that Chinese female college students' favorability toward environmentally sustainable fashion products had a positive effect on their purchase intention. Based on these results, it is judged that companies need to emphasize the characteristics of products such as environmental protective value, economic value, and social value in order to promote consumers' purchase of environmentally sustainable fashion products. The purpose of this study is to help develop marketing strategies for environmentally sustainable fashion products by providing basic data, development ideas, and methods useful for environmentally sustainable fashion-related industries and companies by analyzing the relationship between empathy value, favorability, and purchase intention.

Association between physical activity and periodontitis according to depression among Korean adults (한국 성인의 우울증 여부에 따른 신체활동과 치주질환 간 관련성)

  • Hye-Rim Jeon;Soo-Myoung Bae;Hyo-Jin Lee
    • Journal of Korean Dental Hygiene Science
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    • v.7 no.1
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    • pp.69-81
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    • 2024
  • Background: This study aimed to investigate the association between physical activity and periodontitis based on depression status in a representative sample of Korean adults. Methods: A total of 12,689 subjects who participated in the 7th Korea National Health and Nutrition Examination Survey (2016-2018) were examined. Depression was defined as a PHQ-9 score ≥ 10. Periodontal status was assessed using the community periodontal index, with periodontitis defined as a code ≥ 3. Physical activity categories were divided into a physical activity group and a non-physical activity group, considering the number of days and minutes spent on moderate and vigorous activities. Moderate activity was defined as causing slight breathlessness or a slightly elevated heart rate, while vigorous activity was defined as causing significant breathlessness or a rapid heart rate. Multivariable logistic regression analyses were adjusted for sociodemographic variables (age, sex, education level, and household income), oral and general health behaviors (use of floss and interdental proximal brush, current smoking), and systemic health status (diabetes and hypertension). All analyses utilized a complex sampling design, and subgroup analysis was performed to estimate associations stratified by depression (PHQ-9 ≤ 9 and ≥ 10). Results: Multivariable regression analysis revealed that among participants with depression, those who did not engage in physical activity were 2.65 times more likely to have periodontitis (odds ratio = 2.65, 95% confidence interval = 1.17-6.01). Conclusion: The study findings suggest that individuals who participate in any form of physical activity may be significantly less likely to develop periodontitis, particularly within the group experiencing depression.

A Study on Hydrogeological Characteristics of Deep-Depth Rock Aquifer by Rock Types in Korea (국내 암종별 고심도 암반대수층 수리지질특성 연구)

  • Hangbok Lee;Chan Park;Dae-Sung Cheon;Junhyung Choi;Eui-Seob Park
    • Tunnel and Underground Space
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    • v.34 no.4
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    • pp.374-392
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    • 2024
  • In order to successfully select a site for deep geological disposal of high-level radioactive waste, it is important to perform the stepwise approach along with the systematic selection and survey of evaluation parameters of geological environmental characteristics suitable for the domestic geological environment. In this study, we evaluated the characteristics of hydraulic conductivity, which is considered the most important evaluation parameter in the field of hydrogeology, targeting a deep-depth rock aquifer where actual disposal facilities are expected to be located. In particular, for the first time in Korea, we obtained in-situ pressure-flow data by directly conducting hydraulic tests in boreholes at depths ranging from 500 m to 750 m in various rock types distributed in Korea (granite/volcanic rock/gneiss/mudstone). And we derived hydraulic conductivity values by rock types and depth using verified analytical methods. For this purpose, precision hydraulic testing equipment developed in-house through this study was used, and detailed investigation procedures based on standard test methods were applied to field tests. As a result of the analysis, the average hydraulic conductivity value was found to be in the range of 10-9 m/s in all granite/volcanic rock/gneiss areas. In the mudstone area, an average hydraulic conductivity value of 10-11 m/s was derived, which was about 100 times (2 orders of magnitude) lower than that of the fractured rock aquifers. Moreover, permeability tended to slightly decrease with depth in fractured rock aquifers (granite and volcanic rock areas) containing many rock fractures. The gneiss area tended to have large local differences in permeability according to the composition of the stratum and the development of fracture zones rather than depth. In mudstone areas with weak fracture development, there was no significant variation in rock permeability according to depth. The hydraulic conductivity results by various rock types and depth presented in this study are expected to be utilized in building a foundational database for the site selection, design, and construction of disposal facilities in Korea.

Association between the usage of dental floss and interdental brushes and the prevalence of systemic diseases (치실 및 치간칫솔 사용과 전신질환 유병률의 연관성)

  • Seon-Jip Kim;Hye-Jin Kwon;Hyun-Jae Cho
    • Journal of Korean Dental Hygiene Science
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    • v.7 no.1
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    • pp.17-28
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    • 2024
  • Background: Oral health has a significant impact on systemic health, and the close association between oral and systemic diseases has been continuously reported. To prevent oral diseases, the role of oral hygiene products such as dental floss and interdental brushes, in addition to tooth brushing, is becoming increasingly important. This study aims to analyze the effect of using oral hygiene products on the lifetime prevalence of systemic diseases among Korean adults. Methods: This study utilized data from the 7th Korea National Health and Nutrition Examination Survey (2016-2018). The study population consisted of 13,199 adults aged 19 years and older. The independent variable was the use of oral hygiene products, and the dependent variable was the prevalence of systemic diseases diagnosed by a physician. Demographic variables, health status, and behavioral variables were included as covariates, and multivariable logistic regression analysis was performed. Results: The use of dental floss showed no significant association with the prevalence of systemic diseases. However, those who did not use interdental brushes had a 22% lower likelihood of dyslipidemia (OR 0.777, 95% CI 0.660-0.913). Among participants with periodontal disease, those who did not use dental floss had a significantly higher risk of myocardial infarction (OR 11.488, 95% CI 1.438-91.772). Conversely, those who did not use interdental brushes had lower risks of dyslipidemia, myocardial infarction, and angina, particularly among women and individuals under 65 years of age. Conclusion: This study found a low overall association between the use of oral hygiene products and the prevalence of systemic diseases, but there was a notable association with cardiovascular diseases. To reduce the risk of myocardial infarction, the prevention and treatment of periodontal disease, along with proper oral hygiene management, are crucial. Future prospective studies are needed to clearly establish the causal relationship between oral hygiene and systemic diseases.

A Study on Carbon Stocks Estimation Methods Using Utilizing Both Biotope Maps - A Case Study on Forests in Suji-gu, Yongin City - (도시생태현황지도를 활용한 탄소저장량 추정 방법에 관한 연구 - 용인시 수지구 산림을 사례로 -)

  • Lee, Hak-Gi;Han, Bong-Ho;Park, Seok-Cheol
    • Journal of the Korean Institute of Landscape Architecture
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    • v.52 no.5
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    • pp.27-41
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    • 2024
  • The current method of calculating the carbon stocks of Korea's forests is to multiply the forest standing crop by basic wood density, biomass expansion factor, and carbon fraction, but it does not sufficiently reflect forest vegetation. This study attempted to present a method of calculating carbon stocks using the biotope map and Biomass Allometric Equations for forests in Suji-gu, Yongin City. The biotope map is prepared every five years and contains detailed information on vegetation, including the actual vegetation and land cover status. The forest biotope of Suji-gu was extracted from the Yongin City biotope map, and the tree species, height, and breast height diameter of 24 representative types of forest vegetation sampled in Yongin City were analyzed in detail. To calculate the carbon stocks of trees and shrubs, the Biomass Allometric Equations developed by the National Institute of Forest Science was used, and to calculate the carbon stocks of shrubs, the previous research result of 0.457 kg per m2 was applied. First, carbon storage was calculated for each types of forest vegetation sampled in Yongin City, and in order to apply this to the entire area, the 125 forest vegetation types in Suji-gu, Yongin City were retyped into 50. As a result, the Quercus mongolica community occupied the largest area, followed by the Pinus rigida community, the Quercus acutissima community, and the Quercus serrata community. The community with the highest carbon stocks per unit area (m2) was the Cornus controversa-Quercus mongolica community, and the community with the lowest was the oak-Betula dahurica community. The carbon stocks amount of forests in Suji-gu, Yongin City, calculated by applying the biotope map and Biomass Allometric Equations, was relatively higher than the carbon stocks amount calculated by multiplying existing forest standing crop by basic wood density, biomass expansion factor, and carbon fraction. This is because the currently officially used forest standing crop in Yongin City (144.44 m3/ha) does not sufficiently reflect the actual forest vegetation, and trees with a breast height diameter of less than 6 cm were excluded when surveying forest standing crop, resulting in a lower carbon stocks amount than the actual amount. This study complements the limitations of existing carbon stocks calculation methods by utilizing a biotope map with detailed information on vegetation, such as existing vegetation maps and land cover status, and a Biomass Allometric Equations developed by the National Institute of Forest Science, and provides higher precision when assessing carbon stocks of forests. It is meaningful in suggesting a method for calculating carbon stocks.

Recent Changes and Prospects in the China-Russia-North Korea triangle and the three bilateral relationships (북중러 삼각관계와 3개의 양자관계의 최근 변화와 전망)

  • Jae-kwan Kim
    • Analyses & Alternatives
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    • v.8 no.3
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    • pp.7-44
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    • 2024
  • This article attempts to analyze the changes and prospects of the Northeast Asian security environment in the era of New-Cold War & multipolarity that has been spreading since the outbreak of the US-China strategic competition and the war in Ukraine. Since the war in Ukraine, changes in the new strategic triangle between the United States, China, and Russia have begun to have an unprecedented impact on the Northeast Asian security environment. This article analyzes how the two factors, the U.S.-China strategic competition and the war in Ukraine, have led to changes in the Northeast Asian security environment. More specifically, the recent changes and prospects of the China-Russia-North Korea triangle and the three bilateral relationships, China-Russia, China-North Korea, and Russia-North Korea. To analyze this research topic, the research design is based on three variables: independent, mediating, and dependent variables. The independent variables are changes in U.S.-China relations and changes in U.S.-Russia relations. The mediating variables are the US-China strategic competition and the war in Ukraine. On the one hand, the confrontation between the U.S.-China relationship led to a strategic competition, and on the other hand, the conflict between the U.S.-Russia relationship led to the war in Ukraine. In addition, the two independent variables can only be influenced by the two mediating variables. In particular, we assume that the domestic political factors of the three major powers, the United States, China, and Russia, played a significant role in causing the two mediating variables. The independent variables and mediating variables work together to promote the Northeast Asian security crisis. As a result, threats to the Northeast Asian security environment have emerged as the dependent variable. The dependent variables are the North Korea-China-Russia triangle, changes in the three bilateral relationships within the triangle, and the confrontation of Northern Triangle versus Southern Triangle. The first mediating variable, strategic competition, has led to several changes in the Northeast Asian security environment: the quasi-alliance of Sino-Russian relations, the restoration and strengthening of North Korea-China relations, the strengthening of trilateral security cooperation between the United States, Japan and South Korea, and the increasing necessity of Sino-Russian-North Korean trilateral cooperation. The second mediating variable, the war in Ukraine, has led to the strengthening of Sino-Russian relations, re-alignment of North Korea-Russia relations, the promotion of the US-Japan-ROK triangular alliance, and the emergence of the China-Russia-North Korea triangular cooperation.

Investigation on Effects of Aging on the Formation and Physicochemical Properties of Hydrothermally Synthesized Magnesium Aluminum-Layered Double Hydroxide/Rice Husk Hydrochar Nanocomposites for Effective Remediation of Arsenic-Contaminated Soil (비소 오염토양의 효과적 정화를 위한 열수합성 마그네슘알루미늄-이중층수산화물/왕겨 하이드로차 나노복합체의 형성 및 이화학적 특성에 미치는 에이징 효과 규명)

  • Seon Yong Lee;Chul-Min Chon;Gil-Jae Yim;So-Jeong Kim;Sue A Kang;Young Jae Lee
    • Economic and Environmental Geology
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    • v.57 no.5
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    • pp.577-592
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    • 2024
  • This study presents the synthesis and characterization of MgAl-layered double hydroxide (LDH)/rice husk hydrochar (RHH) nanocomposites (MgAl-LDH/RHHs) via an in situ one-pot hydrothermal route at 150 ℃, utilizing Mg:Al molar ratio of 2:1 for arsenic remediation. The formation of MgAl-LDH/RHHs and their physicochemical properties were evaluated under varying hydrothermal aging times systematically. Prolonging the aging period to 12 hrs significantly enhanced the crystallinity and crystal size of the LDHs, resulting in a 3D hierarchical structure with the highest specific surface area (27.98 m2/g) formed on the hydrochar surface. The hexagonal crystal structure (d003 = 0.8246 nm) was characterized by a rhombohedral unit cell with lattice parameters a = 0.3049 nm and c = 2.4738 nm, and a high positive charge density of 4.284 e/nm2. These properties were found to be favorable for the sorption of arsenic oxyanions. Batch adsorption experiments were conducted to assess the potential of MgAl-LDH/RHHs-12h for the remediation of arsenic-contaminated soils. The original soil sample (CY) was mechanically sieved into fine-grained (CYF, < 75 ㎛) and coarse-grained (CYC, 75 ㎛-2 mm) fractions. When these soil samples were reacted with deionized water, arsenate was identified as the dissolved arsenic species, with concentrations of 2.85 mg/L for CY, 4.02 mg/L for CYF, and 2.55 mg/L for CYC, respectively. Kinetic sorption experiments, conducted at pH 5.0 and 8.0 in the presence and absence of 0.1 M NaCl as a background electrolyte, revealed that arsenic sorption onto MgAl-LDH/RHHs-12h was inhibited at pH 8 in the presence of NaCl. These findings suggest that effective arsenic sorption requires low pH conditions with minimal background electrolytes in soils.

A comparison of the Features of External Representations Presented in Paper Textbooks and Digital Textbooks: Focused on the 'Force' Related Units of Middle School in the 2009 and 2015 National Science Curricula (서책형교과서와 디지털교과서에 제시된 외적 표상의 특징 비교: 2009 및 2015 개정 교육과정의 중학교 '힘' 관련 단원을 중심으로)

  • 김노아;장진아 ;송진웅
    • School Science Journal
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    • v.12 no.3
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    • pp.309-330
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    • 2018
  • Digital textbooks will be an important media for expanding learning materials and ways of communicating in the classroom in a 'hyper-connected society'. The purpose of this study is to compare the types and features of external representations presented in paper textbooks and digital textbooks to see how they were constructed meaningful in a different way. In particular, through comparison of digital textbooks that were approved by the 2009 and 2015 national science curricula, this study intended to diagnose large or small changes depending on the curriculum and seek directions for future developments. As a result, digital textbooks provided quantitative extended data and representations in space beyond physical limits, but these representations were focused on linguistic representations. This tendency was the same in both curricula textbooks, but more diverse types of representations were found in the 2015 national science curriculum. In addition, in th1 digital textbooks, illustrative and explanatory representations was used the most, such as the paper textbooks. However, in the digital textbooks, complementary representations were much bigger than the paper textbooks and summative and performative representations were added. In the digital textbooks of the 2015 national science curriculum, the complementary representations were slightly reduced, and summative and performative representations were relatively more used. Also, in the digital textbooks, space was used as a way of presenting various representations through the pop-up and screen switching functions by click. In particular, in the 2015 national science curriculum, many screen switching functions were presented. Finally, this study suggested implications for the improvement of digital textbooks and science classroom.