• Journal of the Korean Institute of Gas
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• v.25 no.3
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• pp.27-38
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• 2021

We devised the system to automatically shutdown the boiler and to fundamentally block the harmful gases, including carbon monoxide, into the indoor when the exhaust system swerves: (1) The discharge pressure of the exhaust gas decreases when the exhaust pipe is disconnected. The monitoring system of the exhaust pipe is implemented by measuring the output voltage of APS(Air Pressure Sensor) installed to control the amount of combustion air. (2) The operating software was modified so that when the system recognizes the fault condition of a flue pipe, the boiler control unit displays the fault status on the indoor regulator while shutting down the boiler. In accordance with the ventilation facility standards in the "Rules for Building Equipment Standards" by the Ministry of Land, Infrastructure and Transport, experiments were conducted to ventilate indoor air. When carbon monoxide leaked in worst-case scenario, it was possible to prevent poisoning accidents. However, since 2013, the number of indoor air exchange times has been mitigated from 0.7 to 0.5 times per hour. We observed the concentration exceeding TWA 30 ppm occasionally and thus recommend to reinforce this criterion. In conclusion, if the flue pipe fault detection and the indoor air ventilation system are introduced, carbon monoxide poisoning accidents are expected to decrease significantly. Also when the manufacturing and inspection steps, the correct installation and repair are supplemented with the user's attention in missing flue, it will be served to prevent human casualties from carbon monoxide poisoning.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.869-877
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• 2018

This study analyzed the current status of MRI (frequency, amount of treatment) based on the history of application of the MRI health insurance benefit standard and health insurance claim data. MRI examinations began as a health insurance benefit in 2005. In 2005, the indications were restricted for some diseases, but coverage for benefits in 2010, 2013, 2016, and 2018 was expanded. In 2021, the Ministry of Health and Welfare decided to apply health insurance for all MRI examinations. From 2010 to 2017, the number of MRI examinations increased by 86.7% in 2017 compared to 2010, and the amount of treatment increased by 53.5%. According to general characteristics, the number of MRI examinations was higher in women than in men. By age, the number of examinations was the highest among ages 70-79. Outpatient examinations were more frequent than inpatient examinations, and the number of examinations in the tertiary hospitals was the highest among the types of hospitals. The number of brain MRI examinations was the highest in each exam site. In December 2013, the standard of MRI was expanded for heart disease and Crohn's disease, the number of cardiac MRI and abdominal MRI examinations increased in 2014 compared to 2013. However, the number of examinations is small and not associate with the disease, it would be difficult to say that it affected the increase in the total number of MRI examinations. To assess health insurance sustainability and policy effectiveness, monitoring will be necessary.

• Ecology and Resilient Infrastructure
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• v.6 no.2
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• pp.89-100
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• 2019

We've reviewed existing studies on the interactions among vegetation, hydrology, and geomorphology in the stream corridors, adding one more factor of vegetation in the traditional area of hydro-geomorphology. Understanding of the interactions among those three factors is important not only academically but also practically since it is related intimately to the restoration of river corridor as well as management itself. Studies of this area started from field investigations in the latter part of the 20th century and focused on the flume experiments and then computer modelling in the 1990s and 2000s. Now, it has turned again to the field investigations of specific phenomena of the vegetative-hydrologic-geomorphologic interactions in detailed micro scales. Relevant studies in Korea, however, seem to be uncommon and far behind the international status quo in spite that practically important issues related directly to this topic have been emerged. In this study, we propose, based on the extensive literature review and authors' own knowledge and experiences, a conceptual diagram expressing the interactions among vegetation, flow (water), sediment, and geomorphology. Existing relevant studies in Korea since the 1990s are classified according to the categorization in the proposed diagrams and then briefly reviewed. Finally, considering the practical issues of riparian vegetation that have emerged recently in Korea, we propose areas of investigation needed in near future such as, among others, long-term and systematic field investigations and monitoring at multiple river corridors having different attributes on vegetative-hydrologic-geomorphologic interactions, including vegetative dynamics for succession.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.136-142
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• 2021

Open-pit mine development requires continuous management because of topographical changes and there is a risk of accidents if the current status survey is performed directly in the process of calculating the earthwork. In this study, the application of UAV photogrammetry, which can acquire spatial information without direct human access, was applied to open-pit mines development area and analyzed the accuracy, earthwork, and mountain restoration plan to determine its applicability. As a result of accuracy analysis at checkpoint using ortho image and Digital Surface Model(DSM) by UAV photogrammetry, Root Mean Square Error(RMSE) is 0.120 m in horizontal and 0.150 m in vertical coordinates. This satisfied the tolerance range of 1:1,000 digital map. As a result of the comparison of the earthwork, UAV photogrammetry yielded 11.7% more earthwork than the conventional survey method. It is because UAV photogrammetry shows more detailed topography. And result of monitoring mountain restoration showed possible to determine existence of rockfall prevention nets and vegetation. If the terrain changes are monitored by acquiring images periodically, the utility of UAV photogrammetry will be further useful to open-pit mine development.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.374-387
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• 2020

This study was conducted to provide basic data for monitoring the trend of ecosystem change and establishing management plans for wetland protection areas by understanding the status of naturalized plants. In 21 wetland protection areas, 129 taxa, including 10 invasive alien species, were recorded. The naturalized plants appeared mostly as 71 taxa in the Chimsil wetland and were not observed in the Moojechineup and Sumeunmulbaengdui wetlands. Among the naturalized plants, 42 taxa (32.6%) originated from North America. Annual and biennial plants accounted for 68.2% (88 taxa). The frequencies of occurrence of naturalized plants growing in dry secondary grasses such as Erigeron annuus and Trifolium repens were high, and clonal plants that propagated by making stolons and struck roots accounted for 19.4% (25 taxa). The naturalized and urbanization indices showed positive correlations with location factors such as wetland, agricultural land, and used area. However, a negative correlation was found between altitude and forest. Therefore, a management plan that synthetically considers the occurrence frequency and growth characteristics of naturalized plants as well as the locational characteristics of wetland protection areas is required.

• Journal of Korean Society of Forest Science
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• v.110 no.1
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• pp.91-105
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• 2021

We conducted a study to identify the relationships between the investigated factors and provide a methodology and generate data by applying deterioration classes to the Seonjaryeong Forest Trail (4.3 km) in the Baekdudaegan Ridge. The average trail width (1.7 m) and bare width (1.4 m) were wider than those obtained in the previous studies. The frequency of trail deterioration was also high. Specific data on deterioration classes were obtained and evaluated using qualitative criteria. Specific data for heavy class stands at 20.1% in trail grade, 13.3 cm on average, and 16.1 cm in the center of erosion depth, 16.2 cm of CSA, 12.3 kg/cm (20.1 mm) on average and maximum 39.3 kg/cm (29.6 mm) of soil hardness. We observed a positive correlation between the deterioration class and trail grade, and the average and maximum soil erosion depths of the hill side were deeper than those of the ridge. The soil hardness data showed a statistically significant difference in terms of the transect site and calculation method (㎏/㎠, mm). Therefore, trail deterioration was observed at the sites having ≥20% trail grade; thus, continuous monitoring at fixed sites over time will be required for sustainability. Furthermore, the trail grade should be of the utmost priority in trail design and management.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.44-70
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• 2022

This study was carried out to investigate the distribution and characteristics of vascular plants resources in Palbongsan Mt., to compare with previous study and to provide basic information for management and preservation of vegetation. We surveyed eleven times by dividing routes from April of 2018 to May of 2021. The result of this survey revealed a total of 450 taxa, consisting of 101 families, 298 genera, 405 species, 11 subspecies, 28 varieties and 6 forms. Among them, the Korean endemic plants were 8 taxa and the rare plants were 4 taxa. The floristic target species were 30 taxa including 2 taxa of grade IV, 6 taxa of grade III, 7 taxa of grade II, and 15 taxa of grade I. The naturalized plants were 39 taxa, the percent of naturalized plant species was calculated to be 8.67% and urbanization index was 12.15%. Ecosystem disturbance wild plants were 5 taxa. It is considered continuous monitoring and periodic vegetation management of the distribution status of naturalized plants and ecosystem disturbance wild plants found at the edges of forests, fields and forests would be carried out.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.400-414
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• 2021

Under high-level radioactive waste repository conditions, bentonite as an engineered barrier material undergoes thermal, hydrological, mechanical, and chemical processes. We report the applications of X-ray Computed Tomography (CT) imaging technique on the characterization and analysis of bentonite over the past decade to provide a reference of the utilization of this technique and the recent research trends. This overview of the X-ray CT technique applications includes the characterization of the bentonite either in pellets or powder form. X-ray imaging has provided a means to extract grain information at the microscale and identify crack networks responsible for the pellets' heterogeneity. Regarding samples of pellets-powder mixtures under hydration, X-ray CT allowed the identification and monitoring of heterogeneous zones throughout the test. Some results showed how zones with pellets only swell faster compared to others composed of pellets and powder. Moreover, the behavior of fissures between grains and bentonite matrix was observed to change under drying and hydrating conditions, tending to close during the former and open during the latter. The development of specializing software has allowed obtaining strain fields from a sequence of images. In more recent works, X-ray CT technique has served to estimate the dry density, water content, and particle displacement at different testing times. Also, when temperature was added to the hydration process of a sample, CT technology offered a way to observe localized and global density changes over time.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.41-52
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• 2022

Objectives: This study intends to review the impact on cleaning workers and suggest directions for improvement by reviewing the legal and institutional ways in which Article 86 Nos. 7 and 16 of the Enforcement Decree of the Occupational Safety and Health Act work on the maintenance and promotion of cleaning workers' health. Methods: The following laws and systems were reviewed and considered: First, the occupational safety and health legislation obligated or required to be applied to protect the health of cleaning workers; Second, the status of control of chemicals or mixtures used at cleaning sites through the Consumer Chemicals Product and Biocide Safety Control Act; Third, Control of consumer products according to foreign material safety data sheet related laws. Results: Legal and institutional measures necessary to protect the health of cleaning workers include the legal control of harmful substances to be controlled, work environment monitoring, and special health examinations. The application of the Consumer Chemicals Product and Biocide Safety Control Act does not satisfy the legal and practical level of health maintenance and promotion required by the Occupational Safety and Health Act, and the communication of chemical information is insufficient. Overseas, there are restrictions on the use of consumer products in the workplace without material safety data sheets. Conclusions: It is necessary to improve the system to ensure the health of workers handling consumer chemical products. The remaining laws and regulations exempted from the obligation to prepare material safety data sheets should be additionally reviewed.

• Journal of the Korean Regional Science Association
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• v.38 no.4
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• pp.31-44
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• 2022

This study was conducted with the aim of confirming the relevance and effect of the characteristics of the cities and cities in the neighborhood area, focusing on the sale price per square meter of apartment. Specifically, it was intended to determine whether cities in the relevant city and neighborhood area have differential characteristics between the metropolitan area and the non-metropolitan area, whether industrial characteristics, urban planning and development project characteristics, and location characteristics. Comparing the research results of the city and metropolitan area, it was found that there was a correlation in all areas of population characteristics. Industrial and urban planning projects and development project characteristics sectors are not significant in the city, but they appear significant when analyzed in the urban area of the year. When classifying and analyzing the metropolitan area and the non-metropolitan area, both the metropolitan area and the non-metropolitan area were significant in the population sector, and only the distance from Gangnam-gu was significant in the local sector. Since the population is concentrated in the Seoul metropolitan area now, the sale price per square meter of apartments is also concentrated in the Seoul metropolitan area, which is believed to result in such a result. This is judged to be an analysis that appears because the characteristics of the developable status of the metropolitan area and the non-metropolitan area are different. Accordingly, this study shows that the characteristics of neighboring areas as well as the city should be analyzed when analyzing the factors affecting the sale price per square meter of apartment, and suggests that housing market monitoring needs to be carried out together.