• Journal of Wetlands Research
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• v.8 no.2
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• pp.53-64
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• 2006

A study on the restoration process of a stream ecosystem and the water quality renovation technique by removing algae, vegetation and fish monitoring as evaluating the removal of the algae by dietetic characteristics of fishes were performed on Sangdong stream in the B city after stream restoration it to the artificial stream as the cases, restoring urban stream into close-to-nature stream are being increased domestically with the aim of ecological city. As a result, restoration and rehabilitation of the fundamental stream ecosystem was well maintained 4 years later the reclamation at the moment and total 93 diagnosis which were all vascular plant phylum including 44 families, 73 genuses, 79 species and 14 varieties in flora and vegetation community were observed. 3 families, 8 species and 354 populations in total among Fishes were found and Pseudorasbora Parva, Cyprinus Carpic and Carassius Auratus strongly resistant to water pollution were dominantly appeared in order of 50.5% of Pseudorasbora Parva 21.2% of Cyprinus Carpic, 20.9% of Carassius Auratus, 7.1% of Macropodus chinensis and 0.3% of Misqurnus anguillicaudatus according to relative richness index. It turned out to be that Cyprinus Carpic ingests algae over 90% and Carassius Auratus takes it over 30% according to the analysis about the alimentary object of the fishes as a consequences of algae's excrescent from characteristics of the tested experimental stream. It is reported that a Cyprinus Carpic, about 34 cm in length, ingested wet-weight 43.2g algae on the rough analysis toward the sample which makes us recognize how effective a macro community Cyprinus Carpic is for removing algae.As a consequence of this research, the effect of stream ecosystem characteristics and water quality purification could not be expected by aquatic plants and trees which were eliminated at experimental stream. From now on, a close-to-nature stream should be formed of ecological hydraulic and hydrologic engineered modeling from the beginning so that it can perform the water quality purifying function. It is determined that the structure of food chain will be abundantly influenced by the induction of oversized macro community like Cyprinus Carpic because a biomass of a consumer of higher order is increased. It is estimated that the removal algae by fishes is not effective despite in some cases of dietetic characteristics so much more studies should be executed in the future.

• Journal of Wetlands Research
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• v.17 no.2
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• pp.184-192
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• 2015

This study is a basic research for low maintenance constructed wetlands which can prevent water quality deterioration due to wetland soils. The purpose of this study is to analyze water quality control mechanisms of constructed wetland on the artificial ground which installed the modular revetment structure(MRS), a device that separates water and soil. This study was then conducted with two different wetland mesocosms (a treatment plot and a control). These mesocosms were monitored to analyze effects of water quality control of the MRS. A treatment plot was built, and separated into soil and water, by filling the MRS with the decomposed granite soil in the mesocosm made of rubber material. A control plot was built where the decomposed granite soils were exposed to water by leaving the soil on the bottom of the mesocosm made of rubber material. Water quality was then analyzed by using Kolmogorov-Smirnov Z examination which then showed that pH, BOD, SS, Chl-a, T-P, T-N had statistically valid difference between a container with the MRS and one without it. According to the analysis of the water quality, the temperature and the EC level came out similarly and both mesocosm showed same level on pH and DO. A treatment plot had higher levels of BOD, SS Chl-a, and T-P. A control plot's T-N value was little lower than that of the treatment plot. This study suggests method of constructed wetlands using the MRS prevents problems occurring in wetland soils: aridity of wetlands by soil erosion, eutrophication, and algal blooms due to nutrients released from wetland soil. These functions of constructed wetland with the MRS increase aesthetic, ecologic, social, and economic value of the wetland. Outcomes of this research will later enable more proficient way of stabilizing water quality and provide data for planning low maintenance constructed wetlands.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.287-294
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• 2021

In order to expand facility agriculture and reduce greenhouse construction costs in reclaimed land, a greenhouse foundation method that satisfies economic feasibility and structural safety at the same time is required. As an alternative, the allowable bearing capacity and settlement were reviewed when the DCM(Deep cement mixing) method was applied among the soft ground reinforcement methods. To examine the applicability of the greenhouse foundation, the allowable bearing capacity and settlement were calculated by applying the theory of Terzaghi, Meyerhof, Hansen, and Schmertmann. In case of the diameter of 800mm and the width and length of the foundation of 4m, the allowable bearing capacity was 179kN/m² and the settlement was 7.25mm, which satisfies the required bearing capacity and settlement standards. The calculation results were verified through FEM(Finite element method) analysis using the Mohr-Coulomb material model. The allowable bearing capacity was 169kN/m² and the settlement was 2.52mm. The bearing capacity showed an error of 5.6% compared to calculated value, and the settlement showed and error of 65.4%. Through theoretical calculations and FEM analysis, it was confirmed that the allowable bearing capacity and settlement satisfies the design criteria as a greenhouse foundation when the width and length of the foundation were 4m. Based on the verified design values, it is expected to be able to present the foundation design criteria for greenhouses through empirical tests such as bearing capacity tests and long-term settlement monitoring.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.604-617
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• 2018

As the depletion of forests became more widespread due to the increase in the number of roads, the research was conducted on the relationship between temperature and humidity in the forests, assuming that the forests around the roads were affected. Through the forest monitoring, the temperature and humidity of coniferous forests and broadleaf forests in Sedong and Gongju areas were observed at three point of 10m, 20m and 30m from the road boundary to the inside of the forest, respectively. In Yeongdong area, for more reliable results, it was observed from the point of 0m, 10m, and 20m. During the study period, so it was expected the change in tree growth was small, the change of temperature and humidity inside the forest by the road was compared with the temperature and humidity from the road to the inside of the forest from September 2017 to January 2018, the changes of temperature and humidity inside the forest due to linear development such as roads were quantitatively analyzed. Using the HOBO data logger (MX2301, Onset Corp.), the temperature and humidity changes of each site were measured, and the average of the changes have been analyzed monthly. In the case of Gongju coniferous forests in September 2017, the average weekly temperature is $0.57^{\circ}C$ higher than the forest outside from the forest boundary and $1.23^{\circ}C$ higher than the inside of the forest, at night in November 2017, in Sedong broadleaf forests. That is, the ability to control the temperature and humidity of the forests along the road was larger and less variable as the distance from the road boundary to the inside of the forest increased. In this study, it is considered that the high degree of change in temperature and humidity of the forest and the surrounding area due to artificial linear development such as roads will affect the growth of trees. This results could serve as a basis for studying the quantitative scope of linear development affecting forest growth and for managing forest change caused by linear development.

• Korean Journal of Heritage: History & Science
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• v.44 no.2
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• pp.4-25
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• 2011

This study was performed in 2010 to examine the flora and vegetation structure and chemical characteristics of soil in the growing community of Abeliophyllum distichum, located in the Byeonsanbando National Park. This Abeliophyllum distichum community has more individual numbers in Cheongrim-ni and Jungkye-ri, Byeonsan-myeon, and Buan-gun area, which is designated as a Natural Monument (No. 370), and also where the habitat conditions for Abeliophyllum distichum is more favorable. The authors recorded 100 taxa with 45 families, 82 genus, 93 species, 4 varieties, and 3 forms. Among them, species such as Abeliophyllum distichum (critically endangered), Asarum maculatum (near threatened) and Chionanthus retusa (near threatened), which are categorized as rare plants, were recorded. According to the list of Korean endemic plants, 4 taxa, particularly Philadelphus schrenckii, Abeliophyllum distichum, Weigela subsessilis, and Lonicera subsessili, were recorded. The community of Abeliophyllum distichum is located in the northwest slope of Baekcheon watershed and the community is comprised of healthy soil. The community structure was classified into three: the Castanea crenata community, Zelkova serrata community, and Quercus serrata community. The Castanea crenata community is composed of the Cornus walteri, Platycarya strobilacea, Zelkova serrata, Rhamnella frangulioides, arranged in terms of importance percentage. The Zelkova serrata community is composed of Celtis sinensis, Quercus aliena, Styrax japonica, and Acer pseudo-sieboldianum, also according to importance percentage. As for the Quercus serrata community, it is composed of Quercus variabilis, Castanea crenata, and Prunus sargentii, also arranged in terms of importance percentage. The importance percentage of Abeliophyllum distichum is 6.6% in the Castanea crenata community, 5.6% in the Zelkova serrata community and 5.1% in the Quercus serrata community. Moreover, in order of chemical characteristics of soil pH, electrical conductivity, available phosphoric, organic matter, and exchangeable cation (K, Ca, Mg) are analyzed. The No. 3 site was relatively higher than other districts of the same chemical characteristics of soil.

• Journal of The Korean Association For Science Education
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• v.39 no.1
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• pp.13-33
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• 2019

The purpose of this study is to clarify the possibility of the character education and the concrete implementation process in the field of science education in accordance with the social demand for character education. Based on this purpose, the researchers tried to understand the specific character elements appearing in various science learning situations and to understand the qualities of each specific character elements that can be emphasized through science learning and the aspect of expression process in related learning situations. The researchers selected 11 students from the 7th and 8th graders in Seoul and developed and applied the 'Become a Science Teacher' mentor program in 2014 and 2015. Data collection was conducted through class recordings, mentor teachers' and assistant teacher's journal, artifacts, student journals, student portfolios, class listeners' essays for science class and analyzed qualitative data collected through constant comparison method. According to the result, we extracted 11 character elements and reorganized them into 16 specific character elements revealed in various learning situations based on the relationship between each character elements. The results of the study are eight specific character elements that can be emphasized through science learning and related learning situations. The eight specific character elements are 'responsibility for teaching behavior due to hierarchy of scientific knowledge structure, communication for forming scientific concept, empathic concern based on science learning experience, cooperation for promoting rationality of inquiry method, positive perception of scientific endeavor, respect for scientists' attitudes toward research, confidence in future scientific research, persistence in trial and error'. Based on the results of this study, we proposed the research methods of character in the field of science education in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.4
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• pp.15-29
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• 2021

The study aims to grasp the perception and appraisal of urban park users through text analysis. This study used Google review data provided by Google Maps. Google Maps Review is an online review platform that provides information evaluating locations through social media and provides an understanding of locations from the perspective of general reviewers and regional guides who are registered as members of Google Maps. The study determined if the Google Maps Reviews were useful for extracting meaningful information about the user perceptions and appraisals for parks management plans. The study chose three urban parks in Seoul, South Korea; Seoul Forest, Boramae Park, and Olympic Park. Review data for each of these three parks were collected via web crawling using Python. Through text analysis, the keywords and network structure characteristics for each park were analyzed. The text was analyzed, as were park ratings, and the analysis compared the reviews of residents and foreign tourists. The common keywords found in the review comments for the three parks were "walking", "bicycle", "rest" and "picnic" for activities, "family", "child" and "dogs" for accompanying types, and "playground" and "walking trail" for park facilities. Looking at the characteristics of each park, Seoul Forest shows many outdoor activities based on nature, while the lack of parking spaces and congestion on weekends negatively impacted users. Boramae Park has the appearance of a city park, with various facilities providing numerous activities, but reviewers often cited the park's complexity and the negative aspects in terms of dog walking groups. At Olympic Park, large-scale complex facilities and cultural events were frequently mentioned, emphasizing its entertainment functions. Google Maps Review can function as useful data to identify parks' overall users' experiences and general feelings. Compared to data from other social media sites, Google Maps Review's data provides ratings and understanding factors, including user satisfaction and dissatisfaction.

• Korean Journal of Remote Sensing
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• v.38 no.6_3
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• pp.1827-1836
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• 2022

Disasters that occur unexpectedly are difficult to predict. In addition, the scale and damage are increasing compared to the past. Sometimes one disaster can develop into another disaster. Among the four stages of disaster management, search and rescue are carried out in the response stage when an emergency occurs. Therefore, personnel such as firefighters who are put into the scene are put in at a lot of risk. In this respect, in the initial response process at the disaster site, robots are a technology with high potential to reduce damage to human life and property. In addition, Light Detection And Ranging (LiDAR) can acquire a relatively wide range of 3D information using a laser. Due to its high accuracy and precision, it is a very useful sensor when considering the characteristics of a disaster site. Therefore, in this study, development and experiments were conducted so that the robot could perform real-time monitoring at the disaster site. Multi-sensor module was developed by combining LiDAR, Inertial Measurement Unit (IMU) sensor, and computing board. Then, this module was mounted on the robot, and a customized Simultaneous Localization and Mapping (SLAM) algorithm was developed. A method for stably mounting a multi-sensor module to a robot to maintain optimal accuracy at disaster sites was studied. And to check the performance of the module, SLAM was tested inside the disaster building, and various SLAM algorithms and distance comparisons were performed. As a result, PackSLAM developed in this study showed lower error compared to other algorithms, showing the possibility of application in disaster sites. In the future, in order to further enhance usability at disaster sites, various experiments will be conducted by establishing a rough terrain environment with many obstacles.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.347-355
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• 2022

The safety valve (PSV) is a safety device that automatically releases a spring when the pressure generated by various causes reaches the set pressure, and is restored to a normal state when the pressure falls below a certain level. Periodic inspection and monitoring of safety valves are essential so that they can operate normally in abnormal conditions such as pressure rise. However, as the current safety inspection is performed only at a set period, it is difficult to ensure the safety of normal operation. Therefore, evaluation items were developed by finding failure modes and causative factors of safety valves required for safety management. In addition, it is intended to provide decision-making information for securing safety by deriving the priority of items. To this end, a Delphi survey was conducted three times to derive evaluation factors that were judged to be important in relation to the Failure Mode Cause Factor (FMCFs) of the safety valve (PSV) targeting 15 experts. As a result, 6 failure modes of the safety valve and 22 evaluation factors of its sub-factors were selected. In order to analyze the priorities of the evaluation factors selected in this way, the hierarchical structure was schematized, and the hierarchical decision-making method (AHP) was applied to the priority calculation. As a result of the analysis, the failure mode priorities of FMCFs were 'Leakage' (0.226), 'Fail to open' (0.201), 'Fail to relieve req'd capacity' (0.152), 'Open above set pressure' (0.149), 'Spuriously' 'open' (0.146) and 'Stuck open' (0.127) were confirmed in the order. The lower priority of FMCFs is 'PSV component rupture' (0.109), 'Fail to PSV size calculation' (0.068), 'PSV Spring aging' (0.065), 'Erratic opening' (0.059), 'Damage caused by improper installation and handling' (0.058), 'Fail to spring' (0.053), etc. were checked in the order. It is expected that through efficient management of FMCFs that have been prioritized, it will be possible to identify vulnerabilities of safety valves and contribute to improving safety.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.125-137
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• 2022

To assess the characteristics of meiofaunal community fluctuations related to environmental factors, seasonal surveys were conducted in the subtidal zone of Hallyeohaesang National Park. The average depth of the study area was about 20 m, and the average water temperature at the bottom was low in winter(11.33℃) and high in summer(17.95℃). The sedimentary particles mainly comprised silt and clay at most stations. The abundance of meiofauna ranged from 81.7 to 1,296.5 Inds. 10 cm^-2, and the average abundance was 589.3 Inds. 10 cm^-2. The average abundance of meiofauna in each season was the lowest at 416.5 Inds. 10cm^-2 in winter and the highest at 704.5Inds.10 cm^-2 in spring. The dominant taxa were nematodes (about 92%) and harpacticoids (about 5%). In the cluster analysis of meiofaunal communities, they were divided into four significant groups. The largest group mainly contained spring and summer samples, and contained stations with a high nematode density of over 500 Inds. 10 cm^-2 and harpacticoids below 50 Inds. 10 cm^-2 with a high composition ratio of nematodes. In the cluster analysis, no regional division was found between the stations, and it was thought to be divided by the seasons with high abundance according to seasonal variation and the composition ratio of nematodes and harpacticoids. In the Spearman rank correlation analysis, the density of total meiofauna and the most dominant taxa, nematodes, was not significantly related to environmental factors. However, the density of harpacticoids had a significant positive correlation with water depth and a negative correlation with sediment particle size.