• Journal of The Korean Association For Science Education
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• v.38 no.6
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• pp.853-864
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• 2018

In this study, we surveyed the 68 teachers from eight science high school and four science academy for the gifted through questionnaires about research ethics education and ethical research environment in Korea. First, we examined the current state of research ethics education. Half of the responding schools included research ethics education in their curriculum. Although only half of the schools have this in their curriculum, more than half of the total number of teachers surveyed personally taught research ethics in class, and almost 90% of the teachers said they taught the research ethics during students' research activity. However, 63.24% of teachers said that research ethics education was not enough still. Second, we investigated the ethical research environment. In terms of knowledge and experience, the teachers were competent, and they were creating an environment that enabled peers and self-verification. However, research ethics, regulations and verification systems are not well equipped in schools. Since the principals are highly interested in research ethics education, there seems to be enough improvement on the ethical research environment. Finally, teachers said that additional research ethics education, change in student attitude, development and continuous maintenance of the verification system, encouragement to develop ethical environment, and clear guidelines were needed for ethical research of students. The result of this research will be able to provide the following. First, it will help set up a direction for research ethics education at every gifted school. Second, it will provide insights on how schools and teachers can create an ethical research environment for the students of science-gifted students.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.3
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• pp.198-205
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• 2019

The small yellow croaker (Larimichthys polyactis) is one of the representative high-class fish species in Korea. The catch of small yellow croaker in adjacent water fisheries has been continuously decreasing from 59,226 tons in 2011 to 19,271 tons in 2016. The small yellow croaker is caught by gillnet, stow net and bottom trawl, among which about 55~65% is caught by gillnet. For the sustainable use of small yellow croaker, the fishing power of small yellow croaker drift gillnet is very important. Therefore, the change of fishing power index were analyzed to identify the development of the vessel and gear technology that may have improved the fishing efficiency of the small yellow croaker drift gillnet fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. The mesh size was 75.0 mm in the 1960s, but reduced to 60.6 mm in the 1980s and to 51.0 mm in the 2000s. In the 1960s, it was hauled out by manpower. However, the net hauler were modernized and supply rate was also increased since 1970. Due to the mechanization of the net hauler, the number (length) of used net gradually increased from 1.5 km in the 1960s to 7.5 km in the mid-1980s and to 15 km in 2010. Colour fish finders and positioning system were introduced and utilized from the mid-1980s. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the small yellow croaker drift gillnet fishery increased from 1.0 in 1980 to 0.8 in 1970, to 1.1 in 1990, to 1.6 in 2000 and to 1.9 in 2010. The results are expected to contribute to reasonable fisheries stock management of the small yellow croaker drift gillnet fishery.

• Particle and aerosol research
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• v.15 no.2
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• pp.79-90
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• 2019

It is important to control fine particles in children care centers, elementary schools, elderly care facilities and so on where vulnerable children and the aged stay during most of their time. This study has investigated $PM_{2.5}$ and $PM_{10}$ concentrations in two classrooms equipped with an air cleaner and two air cleaners, respectively and they were compared to those in a classroom without an air cleaner as well as those outdoors. Eight air cleaners which have various clean air delivery rates (CADRs) between 9.9 and $21.3m^3/min$ were tested in classrooms in two elementary schools in Seoul. Average $PM_{2.5}$ and $PM_{10}$ were $7.3{\pm}0.7$ and $45.5{\pm}4.1{\mu}g/m^3$ in classrooms equipped with an air cleaner and $4.2{\pm}0.6$ and $24.6{\pm}2.5{\mu}g/m^3$ in classrooms with two air cleaners, whereas they were $22.1{\pm}2.6$ and $109.1{\pm}9.6{\mu}g/m^3$ in classrooms without an air cleaner and $36.9{\pm}5.1$ and $74.1{\pm}10.6{\mu}g/m^3$ outdoors, respectively. $PM_{2.5}$ in classrooms could be reduced effectively by using an air cleaner or two air cleaners, because $PM_{2.5}$ was mainly infiltrated from outdoors, however $PM_{10}$ could not because $PM_{10}$ was mainly caused indoors by students' activities. Air cleaners were more effective for removal of $PM_{2.5}$ and $PM_{10}$ in classrooms with a high airtightness than those in classrooms with a relatively low one. Average $CO_2$ in classrooms was about 1500 to 2000 ppm for class hours dependent on the student number per a classroom, which was about 1.5 to 2 times higher than the standard, regardless of the use of air cleaner.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.234-253
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• 2018

Within the Gyeongju Basin lies the central an ancient tombs (Wolseongbuk tombs), which are seen to be the core tombs of the Silla ruling class. An accurate understanding of the location of the ancient tombs, commonly known as a flatland area, provides a clue to understanding the contrast process and direction of the ancient tombs. This in turn requires an accurate understanding of the surrounding landscape, including where the ancient tombs are located. In other words, it must be possible to restore as much of the highland area as possible within the basin in which the ancient tombs are located. All data were analyzed as deeply as possible in order to identify the topographical features of the ancient tombs. As a result, it appears that the ancient tombs are located at the end of a fan or at the end of the line, and a large number of springs and wetlands are distributed around the area. This area is relatively low and unsuitable for generating high levels of moisture on the ground. These topographical features are directly related with the distribution of polymers, and solids were completely formed to avoid wetlands. Meanwhile, the ancient tombs are divided into several zones by springs and wetlands, and each area also has the characteristics of large groups where the boundaries are protruding and isolated. Also, this aspect was found to be true for the Oreung around Namcheon. After all, the location and distribution of Silla in the Daerungwon area are the result of the reflection of the fine geographical features of the Gyeongju basin, which are the key factors of springwater and wetlands.

• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.402-407
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• 2019

In this study, we investigated the habitat characteristics of a reservoir in Gyeongju City, Gyeongbuk, in which a large group of Mauremys reevesii (endangered species Class II and natural monument No. 453 in Korea) was discovered. We examined the biotic and abiotic factors that directly and indirectly threaten the survival of M. reevesii within the habitat. The reservoir where M. reevesii was discovered was built for agriculture and surrounded by submerged trees, dam, forests, reeds, and farmland (paddy field). All of the M. reevesii were found only in the submerged trees on the north side of the reservoir. We found 28 M. reevesii (8 juveniles) and 21 M. reevesii (16 juveniles) from field surveys on May 10th and August 9th, 2018, respectively. A number of red-eared sliders (Trachemys scripta elegans) and American bullfrogs (Rana catesbeiana), which threaten the survival of M. reevesii, were also found in and around the reservoir. Moreover, there were signs of excavation of cultural asset, chemical fertilizer, and household garbage, all of which are considered to be major threats to the survival of M. reevesii, all over the reservoir. Newborn turtles in this year were not observed. However, we estimated that natural breeding had sufficiently occurred since we observed many young turtles in the reservoir. Furthermore, the presence of young T. s. elegans individuals can be a persistent problem for M. reevesii as they are competing species. In conclusion, in-situ conservation method should be considered for protecting the endangered turtle and their habitat.

• Journal of Korea Water Resources Association
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• v.52 no.1
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• pp.35-49
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• 2019

This study proposes a new method for categorizing the hydrological soil groups by considering the recent revision results of soil series. Also, the proposed method is evaluated by comparing the categorizing result with those based on existing three different methods. As an example, the proposed method is applied to Jeju Island to estimate the CN value, which is then compared with CN values estimated by applying the existing three different methods. Summaries of the results are as follow. (1) The revision result since 2007 shows that the soil texture has been changed in the 43 soil series, the drainage class in the 1 soil series, the permeability in the 15 soil series, and the impermeable layer in the 26 soil series. (2) The categorizing result of hydrological soil groups by applying the proposed method shows that the group B is the most dominant group covering up to 49.25%. On the other hand, one of the existing method of 1987 provides the group C as the most dominant group (46.43%). Method of 1995 defines the group B as the most dominant group (27.69%). The other method of 2007 distinguishes the group D (35.82%) to be the most dominant group. (3) Also, the CN value estimated by applying the proposed method to Jeju Island is found to be smaller than those based on existing three methods. This result indicates the possible overestimation of the CN value when applying the existing three methods.

• Korean Journal of Optics and Photonics
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• v.33 no.6
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• pp.295-302
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• 2022

In this paper, a wedge prism application method was studied to design a full-high-definition (FHD)-class high-resolution flexible endoscope. In the case of the conventional flexible endoscope optical system, the F number is made large or a liquid lens is applied to obtain the same imaging performance in a wide depth of field. However, there is a problem in that the diameter of the optical system increases because an additional light guide and equipment are required. To solve this problem, two wedge prisms were applied to the flexible endoscope optical system to adjust the image distance for each object distance. First, two wedge prisms were symmetrically placed on the designed endoscopic optical system. An image distance satisfying the target imaging performance according to each objective distance was derived. Next, the wedge prism decenter value for controlling the image distance was derived. By combining these two data, a wedge prism decenter value that satisfied the target imaging performance at each object distance was applied in multi configurations. As a result of the optimal design applied with the wedge prism, a target imaging performance of more than 20% of the modulation transfer function for a resolution of 178 cycles/mm was satisfied in the entire depth of field of 100 mm-7 mm.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.52-67
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• 2020

Recently, the Arctic has been exposed to snow-covered land due to melting permafrost every year, and the Korea Geographic Information Institute(NGII) provides polar spatial information service by establishing spatial information of the polar region. However, there is a lack of spatial information on vegetation sensitive to climate change. This research used a multi-temporal Sentinel-2 image to perform land cover classification of the Ny-Ålesund in Arctic Svalbard. In the pre-processing step, 10 bands and 6 vegetation spectral index were generated from multi-temporal Sentinel-2 images. In image-classification step is consisted of extracting the vegetation area through 8-class land cover classification and performing the vegetation species classification. The image classification algorithm used Random Forest to evaluate the accuracy and calculate feature importance through Out-Of-Bag(OOB). To identify the advantages of multi- temporary Sentinel-2 for vegetation classification, the overall accuracy was compared according to the number of images stacked and vegetation spectral index. Overall accuracy was 77% when using single-time Sentinel-2 images, but improved to 81% when using multi-time Sentinel-2 images. In addition, the overall accuracy improved to about 83% in learning when the vegetation index was used additionally. The most important spectral variables to distinguish between vegetation classes are located in the Red, Green, and short wave infrared-1(SWIR1). This research can be used as a basic study that optimizes input characteristics in performing the classification of vegetation in the polar regions.

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.130-141
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• 2021

By reviewing previous literature, we analyzed the food sources of 20 out of 29 endangered fish species from freshwater ecosystems in South Korea. A total of 19 studies reported that food sources of 20 endangered fish species included 20 phyla, 31 classes, 58 orders, 116 families, and 154 genera. Arthropod, insecta, diptera, and chironomidae were the most fed animal food sources according to different resolution of taxa index on phylum, class, order and family. Similarity, bacillariophyta, bacillariophyceae, naviculales, and cymbellaceae were the most fed abundant plant sources. A larger number of fish species were reliant on animal food sources than plant food sources. 18 of the endangered fish preyed on arthropods, whereas only 6 species consumed bacillariophyta. To characterize the feeding groups of the 20 fish species, a hierarchical clustering analysis and non-metric multidimensional scaling analysis were conducted. The fish species were divided into two groups: 1) insectivores and 2) planktivores. A network analysis, which associated the link between endangered fishes and food sources, also revealed the same two groups. The highest hub score of food sources was for macroinvertebrates, including diptera (0.47), ephemeroptera (0.42), and trichoptera (0.38), based on the network analysis. Niche breadth was used to calculate the diversity of the food sources. Phoxinus phoxinus (0.57) showed thehighest food source diversity among the fish species, whereas Iksookimia pacifica (0.01) showed the lowest. This study will be utilized for the conservation and restoration of the endangered fish species.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.305-312
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• 2021

This study aims to analyze the changes (2011→2021) in social and environmental factors, such as actual construction activities, including building development and officially assessed individual land price, of the areas that have been released from the park during the second national park area adjustment period (2010~2011) and compare them with those of the areas that retained parks in the same period to analyze the development impact. In the released area, a building has been constructed per 16,431 square meters since 2011. Moreover, both the number of floors and height of the building has increased, and it was analyzed that the class 2 neighborhood living facilities occupied the highest proportion of the building use. Officially assessed individual land prices increased by 42.3% in the released area and 38.6% in the retained area. The analysis by region showed that the officially assessed land price increased by 55.2% on average in both released and retained areas in Seoul and 9.4% in Gyeonggi-do, indicating a much larger increase in the Seoul region. The issue of private property rights in national parks was mostly resolved as they were released through the second national park area adjustment. However, the Korea National Park needs to promote the benefits of landowners by suggesting rational alternatives such as adjustments to the park zoning and facility planning.