• Title/Summary/Keyword: Proportion analysis

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Analysis of Factors That Cause Light Pollution in Islands in Dadohaehaesang National Park (다도해해상국립공원 내 섬 지역의 빛공해 유발 요인 분석)

  • Sung, Chan Yong
    • Korean Journal of Environment and Ecology
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    • v.36 no.4
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    • pp.433-441
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    • 2022
  • Light pollution is one of the factors that disturb coastal and island ecosystems. This study examined the factors causing light pollution in the islands in Daedohaehaesang National Park using nighttime satellite images. This study selected 101 islands with an area of 100,000 m2 or more in Daedohaehaesang National Park, and measured the levels of light pollution of the selected islands by calculating mean nighttime radiance recorded in VIIRS DNB monthly images for January, April, August, and October 2019. Of seven districts of the park, The highest mean nighttime radiance was recorded in Geumodo district (17,666nW/m2/sr), followed by Geonumdo·Baekdo, Narodo, Soando·Cheongsando districts. By season, mean nighttime radiance in October was the highest at 9,509nW/m2/sr, followed by August, January, and April. Regression analyses show that the total floor area and the number of lighthouses in a 5 km buffer area had a statistically significant effect on mean nighttime radiance at all times, but those within the island did not, indicating that light pollution in islands in a national park where land development is strictly restricted is influenced by artificial lights in nearby areas. However, the total floor area of an island significantly affected mean nighttime radiance only in August, which appears to be attributed to the impact of intensive use of artificial light by visitors during summer vacation. The size of an island had a negative (-) effect on nighttime radiance. This negative effect suggests that light pollution is a type of ecological edge effect, i.e., the smaller island is more likely to have a relatively larger proportion of edge area that is affected by light emitted from the neighboring areas. The results of this study indicate that managing artificial lights in nearby areas is necessary to mitigate light pollution in islands in marine and coastal national parks.

Evaluation of Growth Inhibition for Microcystis aeruginosa with Ultrasonic Irradiation Time (초음파 조사시간에 따른 Microcystis aeruginosa의 성장억제 평가)

  • Kang, Eun Byeol;Joo, Jin Chul;Jang, So Ye;Go, Hyeon Woo;Park, Jung Su;Jeong, Moo Il;Lee, Dong Ho
    • Ecology and Resilient Infrastructure
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    • v.9 no.3
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    • pp.183-193
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    • 2022
  • The growth inhibitory effect of Microcystis aeruginosa according to the ultrasonic irradiation time was evaluated using a large algae sample volume (10 L) for various ultrasonic irradiation times (0.5, 1, 1.5, 2, 2.5 and 3 hr) at a laboratory scale. Based on the analysis of Chl-a and cell number of M. aerginosa, algae growth inhibition was observed with the decrease in Chl-a and cell number in all experimental groups after the ultrasonic irradiation. For the experimental group (T_B, T_C, T_D) with an ultrasonic irradiation time of less than 2 hours, rapid regrowth of algae was observed after growth inhibition, but the experimental group (T_E, T_F, T_G) with an irradiation time of more than 2 hours successfully inhibited algal growth lasting one or two more days. Based on the comparison of the recovery time to initial cell number the experimental group (T_B, T_C, T_D) took less than 20 days whereas the experimental group (T_E, T_F, T_G) took about 30 days. Correspondingly, the experimental group showed a high first order decay rate (𝜅) in proportion to the ultrasonic irradiation time during the growth inhibition period. Additionally, the specific growth rates (𝜇) during regrowth in the experimental group with irradiation time of more than 2 hours were relatively low compared to those in the experimental group with less than 2 hours. Therefore, ultrasonic irradiation for more than 2 hours is required for long-term (30 days) inhibition of algal growth in stagnant waters. However, the appropriate ultrasonic irradiation time for algae growth inhibition should be determined according to various field conditions such as the volume of stagnant water, water depth, flow rate, algae concentration, etc. Finally, damages to the algal cell surface and cell membrane were clearly observed, and both destruction and disturbance of gas vesicles of M. aeruginosa in the experimental group were discovered, indicating the growth inhibitory effect of Microcystis aeruginosa according to the ultrasonic irradiation time was confirmed.

The association between nutrition label utilization and disease management education among hypertension or diabetes diagnosed in Korea using 2018 Community Health Survey: a cross-sectional study (고혈압·당뇨병 진단자의 영양표시 활용과 질환관리교육의 연관성: 2018년 지역사회건강조사 자료를 활용한 횡단연구)

  • Miran Jin;Jayeun Kim;Kyuhyun Yoon
    • Korean Journal of Community Nutrition
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    • v.28 no.1
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    • pp.38-47
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    • 2023
  • Objectives: This study examined the association between the experience of disease management education and the use of nutrition labels according to the sociodemographic characteristics and health behaviors of people diagnosed with hypertension and diabetes living in the community. Methods: Among the participants from the Community Health Survey (2018), 74,283 individuals diagnosed with hypertension or diabetes were included in the study population. According to gender, this study evaluated nutrition label use by the experience of disease management education, individual sociodemographic characteristics, and health behavior. Finally, using multiple logistic regression analysis, the association between disease management education and nutrition labels was calculated using the odds ratio (OR) and 95% confidence interval (CI). Results: Males (24.5%) experienced more disease management education than females (22.6%). In addition, younger age, higher education level, and higher equalized personal income experienced more disease management education (P < 0.001). The educational experience rate was higher in the male subjects who did not smoke or were involved in high-risk alcohol consumption (P < 0.001). In addition, the rate of disease management education experience was significantly higher for both men and women who exercised by walking (P < 0.001). The use of nutrition labels was higher in females (9.9%) than males (5.8%), and both males and females were significantly higher in young age, high education, high income, and professional and office positions (P < 0.001). The utilization rate of nutrition labels was high in non-smoking male subjects and high-risk-drinking female subjects. In addition, the utilization rate of nutrition labels was significantly higher in males and females who exercised by walking and those who experienced disease management education (P < 0.001). After adjusting for individual sociodemographic characteristics, health behavior, and disease management education, the use of nutrition labels was high among females (OR 3.19, 95% CI 2.85-3.58), high income (Q4; OR 1.62, 95% CI 1.41-1.87, Q5; OR 1.58, 95% CI 1.37-1.84) and highly educated (high school; OR 2.87, 95% CI 2.62-3.14, above college; OR 5.60, 95% CI 5.02-6.23) while it was low in the elderly (OR 0.43, 95% CI 0.40-0.47), and economically inactive (OR 0.86, 95% CI 0.76-0.96). The use of nutrition labels was high in non-smokers (OR 1.29, 95% CI 1.13-1.48), nonhigh-risk drinkers (OR 1.22, 95% CI 1.08-1.38), and subjects who exercised walking (OR 1.44, 95% CI 1.34-1.54). There was no difference in the utilization rate of nutrition labels according to obesity, and the utilization rate of nutrition labels was significantly higher in subjects who had experienced disease education (OR 1.34, 95% CI 1.24-1.44). Conclusions: Education on the use of nutrition labels, which contributes to food selection for healthy eating, might be a tool for dietary management. Moreover, the utilization rate can be a good indicator for predicting the proportion of the population practicing the guide for disease management. Improving the utilization rate of nutrition labels through disease management education can be a useful intervention for people with chronic diseases who need healthy eating habits for disease management and preventing complications, particularly those diagnosed with hypertension and diabetes.

Study on Horizontal and Vertical Temperature Analysis of Cable Fire in Common Duct using Room Corner Experiment (룸코너 실험을 이용한 공동구 케이블 화재 시 수평·수직 방향 온도 분석에 관한 연구)

  • JaeYeop Kim;SeHong Min
    • Journal of the Society of Disaster Information
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    • v.19 no.3
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    • pp.634-643
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    • 2023
  • Purpose: Underground common duct fires are steadily occurring, and the proportion of property damage is particularly large among property and human casualties caused by fires. Especially, cable fires that occur in common areas can spread vertically quickly and pose a great risk. This paper aims to scientifically analyze the nature of the fire by reproducing the fire through experiments. Method: To analyze the characteristics of cable fires in underground common duct, heat release rate and temperature changes were measured through Room-corner (ISO 9705) test, and the vertical and horizontal propagation of cable fires was quantitatively compared and analyzed. Result: The Room Corner Test (ISO 9705) was used to compare the temperature changes at each data logger point. The results showed that the time it took for the fire to reach the ignition temperature in the horizontal and vertical directions from the center point of the first-tier cable was 589 seconds and 536 seconds, respectively, which means that the vertical fire propagation is 53 seconds faster than the horizontal propagation. This proves that the vertical propagation of fire is relatively faster than the horizontal propagation. The horizontal propagation speed of the fire was also compared for each floor cable tray. The results showed that the third-tier cable propagated at 3.4 times the speed of the second-tier cable, and the second-tier cable propagated at 1.5 times the speed of the first-tier cable. This means that the higher the cable is located, the faster the fire spreads and the larger the fire becomes. Conclusion: This study identified the risks of cable fires and analyzed the risks of vertical fire propagation during cable fires based on the results of the Room Corner Test. Studies to prevent the spread of fire and fire response policies to prevent vertical fire propagation are required. The results of this study are expected to be used to assess the fire risk of common areas and other fires.

A Study on the Current State of Pediatric Dentists and the Adequacy of Supply and Demand Based on Covered Services (소아치과 전문의 인력 현황 및 공급 적정성에 관한 연구 - 급여 진료 항목을 기준으로)

  • Yeo Won Lim;Yong Kwon Chae;Ko Eun Lee;Ok Hyung Nam;Hyoseol Lee;Sung Chul Choi;Mi Sun Kim
    • Journal of the korean academy of Pediatric Dentistry
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    • v.50 no.3
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    • pp.360-372
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    • 2023
  • The aim of this study was to identify the current state of pediatric dentists, evaluate the adequacy of pediatric dentist supply and demand, and find out the perception of all pediatric dentists on the current state of pediatric dentists and policy establishment. An Online survey was conducted among pediatric dentists. The questionnaire was subdivided into 'general characteristics', 'number of dental treatments and working days per year', 'proportion of covered services', 'perceptions of supply and demand of pediatric dentists'. Through the Korean Academy of Pediatric Dentistry, the Health Insurance Review and Assessment Services, the National Health Insurance Service (NHIS), and the Korean Statistical Information Service, the current state of pediatric dentists, the number of claims for covered services, and the decrease in births per year were investigated. Dental clinics claiming to be pediatric dentistry reached half of all medical institutions, but only 3.78% of pediatric dentists actually worked. 61.36% of all pediatric dentists were concentrated in the metropolitan area, showing a national imbalance. Although the population of children and adolescents have continuously decreased over the past 20 years, the number of NHIS-covered services has shown a continuous increase. Over the past 10 years, the optimal supply of pediatric dentists has been maintained at around 4,000. According to the analysis, 92.15% of pediatric dentists thought that it was necessary to prepare policies and support measures at the government level. This study is expected to be used as basic data for establishing a demand estimation method for pediatric dentistry specialists in the future.

Phytoplankton Variability in Response to Glacier Retreat in Marian Cove, King George Island, Antarctica in 2021-2022 Summer (하계 마리안 소만 빙하후퇴에 따른 식물플랑크톤 변동성 분석)

  • Chorom Shim;Jun-Oh Min;Boyeon Lee;Seo-Yeon Hong;Sun-Yong Ha
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.5
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    • pp.417-426
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    • 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.

Fish Community Structures and Distribution Characteristics of Fisheries Resources in the Osip Stream and Wangpi Stream, Fishery Resources Protection Areas (내수면 수산자원보호구역 오십천 및 왕피천의 어류군집 구조 및 수산자원 분포특성)

  • Kyung-hoon Kim;Jin-wang Lee;Young-bin Jo;Jae-Hyun Lim;Ji-Woong Choi
    • Korean Journal of Ecology and Environment
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    • v.56 no.1
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    • pp.57-69
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    • 2023
  • The objectives of this study were to analyze the fish community structures and distribution characteristics of fisheries resources in the Osip Stream and Wangpi Stream, fishery resources protection areas. For the study, we conducted fish samplings four times in the two streams from April to October 2019. In Osip Stream and Wangpi Stream, we sampled 31 species and 29 species and the dominant species were Zacco platypus (28.6%) and Squalidus multimaculatus(41.7%), respectively. According to the life type of fish species, primary freshwater species were collected 18 species(58.1%) and 21 species(72.4%), and migration fishes were sampled 4 species (12.9%) and 6 species (20.7%) in Osip Stream and Wangpi Stream, respectively. Fisheries resources species showed high relative abundance in June, and the fish biomass was highest in October. As a results of comparing the previous studies with this study, both rivers showed high biodiversity and were found to maintain stable populations of fishes. According to analysis of tolerance guilds, the proportion of tolerant species, based on the number of individuals, was composed of 14.4% and 1.1% in Osip Stream and Wangpi Stream, respectively. This very low ratio of tolerant species confirmed that both streams have very good physiochemical environment conditions. From the above results, it was judged that the fishery resource protection areas of Osip Stream and Wangpi Stream have high ecological function and preservation value. For sustainable use and management of fishery resource protection areas of Osip Stream and Wangpi Stream, it is suggested that biological disturbance management, fish discharge projects considering environmental capacity, efforts to improve the habitat environment, and establishing a fishery resource protection areas management system were necessary as considerations.

Comparison of Habitat Quality by the Type of Nature Parks (자연공원 종류별 서식지질 비교)

  • Jung-Eun Jang;Min-Tai Kim;Hye-Yeon Kwon;Hae-Seon Shin;Byeong-Hyeok Yu;Sang-Cheol Lee;Song-Hyun Choi
    • Korean Journal of Environment and Ecology
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    • v.36 no.6
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    • pp.553-565
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    • 2022
  • Awareness of the ecological value and importance of protected areas has increased as climate change accelerates, and there is a need for research on ecosystem services provided by nature. The natural park, which is a representative protected area in Korea, has a system of national parks, provincial parks, and county parks. National parks are managed systematically by the Korea National Park Service, but local governments manage provincial parks and county parks. There may be the same hierarchical differences in naturalness (habitat quality) depending on the hierarchy of the natural parks, but it has not been verified. To identify differences, we examined 22 mountain-type natural parks using habitat quality using the INVEST model developed by Stanford University. The analysis of the habitat quality, regardless of the type and area of the natural park, showed that it was higher in the order of Taebaeksan National Park (0.89), Juwangsan National Park (0.87), Woongseokbong County Park (0.86), and Gayasan National Park (0.85). The larger the area, the higher the value of habitat quality. A comparison of natural parks with similar areas showed that the habitat quality of national parks was higher than that of provincial parks and parks. On the other hand, the average habitat quality of county parks was 0.83±0.02, which was 0.05 higher than that of provincial parks at 0.78±0.03. Furthermore, the higher the proportion of forest areas within the natural park, the higher the habitat quality. The results confirmed that the naturalness of natural parks was independent of their hierarchy and that there are differences in naturalness depending on land use, land coverage, and park management.

First report of Telenomus remus Nixon(Scelionidae), an egg parasitoid of Spodoptera frugiperda(J.E. Smith)(Noctuidae) in Korea and its biological characteristics (한국에서 열대거세미나방 알기생벌 Telenomus remus Nixon (가칭: 밤나방검정알벌)[검정알벌과]의 첫 보고 및 생물적 특성 연구)

  • Jum Rae Cho;Bo Yoon Seo;June Yeol Choi;Gwan Seok Lee;Meeja Seo;Jeong Hwan Kim
    • Korean Journal of Environmental Biology
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    • v.40 no.2
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    • pp.187-198
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    • 2022
  • In this study, Telenomus remus Nixon (Hymenoptera: Scelionidae) was first reported as a natural enemy of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) egg collected from corn fields in Korea, and its biological characteristics was studied. Based on morphological and molecular analysis, the parasitoid emerged from S. frugiperda eggs was identified as T. remus. We found that T. remus can attack the eggs of S. frugiperda, Spodoptera litra and Spodoptera exigua under a laboratory condition. The longevity of T. remus female adult was longer than that of male adult. The egg-to-adult period of T. remus was not affected by the host age and sex. T. remus female adult laid at least 1-3 eggs a day to a maximum of 37 or more eggs, and the most oviposited on the 3rd to 4th day after emergence. The host preference for oviposition of T. remus adult was high in the order of S. litura>S. exigua>S. frugiperda. T. remus preferred to parasitize 1- and 2-day-old host egg rather than 3-day-old host egg. When compared to the sex ratio of T. remus progeny, the rate of female progeny was higher at the initiation time of oviposition, while the proportion of male progeny increased significantly with female adult age, especially after 8-day-old adult. This information may be useful for improving T. remus mass rearing system and developing a biological control program to control S. frugiperda.

Jeonghyesa Temple reconstructed at Yesan by Mangong and the meaning of the creation of the stone standing Avalokiteśvara statue during the Japanese colonial period (일제강점기 만공(滿空)의 예산 정혜사 중창과 석조관음보살입상 조성의 의미)

  • Lee Jumin
    • Korean Journal of Heritage: History & Science
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    • v.56 no.1
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    • pp.22-43
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    • 2023
  • This paper deals with the stone standing Avalokitesvara statue in Jeonghyesa Temple that was created by Mangong in 1924. The stone standing Avalokitesvara statue of Jeonghyesa Temple is the earliest extant Buddha statue produced by Mangong, and symbolism was given to Jeonghyesa in the process of its reconstruction. So far, there has been no study that has approached ideas and beliefs through Buddhist studies led by Mangong and specific relics. In order to proceed with this study, Mangong's legal words and anecdotes and newspaper articles during the Japanese colonial era were used to trace the dynamics of Jeonghyesa and Sudeoksa during Mangong's reign, and to investigate the effects obtained from the creation of the large Bodhisattva statue and the meaning of its location. In addition, an interview was attempted with the descendants of master, who were in charge of the sculpture at the time, to confirm the exact construction period and the list of craftsmen. It is judged that the stone standing Bodhisattva statue of Gwanchoksa Temple has been influenced by the double covering and square crown seen in the standing stone statue of Avalokitesvara Bodhisattva of Jeonghyesa Temple, the large hands compared to the body, the proportion between the head and the body, and the sense of enormity felt in the body like a stone pillar. Therefore, we looked at how the standing stone Bodhisattva statue of Gwanchoksa Temple, which was produced in the early Goryeo Dynasty, could have influenced the creation of the Bodhisattva statue in the modern period. A multilateral analysis was attempted on how the image of the Gwanchoksa Bodhisattva statue, which was used as a symbol representing Chungcheongnam-do in the Chosun Exposition held in 1929 and the visit to Gwanchoksa Temple, which began with the laying of the railroad during the Japanese colonial period, was used from the viewpoint of the succession and transformation of the style. With this study as an opportunity, it is hoped that the understanding of the prehistoric Mangong representing the modern period and the horizon of Korean Buddhist sculpture research in the modern period will be broadened.