• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.281-282
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• 2003

The significant spring-time phenomenon known as the "Yellow Sand" influences not only regional but also global climate. It′s believed that frequency of yellow-sand events has increased in recent years. To investigate the possible factors inducing these special strong weather phenomenon and its impacts on meteorological elements, intensive sampling will be conducted by ADEMRC/KJIST from March to May 2003. Lagrangian trajectory (forward and backward), cluster analysis, factor analysis and satellite remote sense (SRS) techniques will be employed to inspect the mechanisms of yellow-sand. (omitted)

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.1 s.120
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• pp.79-87
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• 2007

The objective of this study was to delineate forest patches in the cities around the Geum-buk mountains at the north of the Geum River using multiplesatellite remote sensing data. Landsat visible and near-infrared satellite images obtained at multiple dates in the growing season were used to create a forest distribution map. Fragstats 3.3 was used to get the landscape indices delineating the distribution of forest patches. Additional ground truth data was used to assess the accuracy of the classification. Factor analysis was used to get the 26 landscape indices clustered into 4 factors. Factor I was labeled as' size of forest patches', factor II as 'fragmentation of forest patches', factor III as 'shape of forest patches', and factor IV as 'complexity of forest patches'. Factor I described large patches and their core area, while others did small patches and their shape and complexity. Cities including Cheonan, Gongju, Cheongyang, and Boryeong near the main ridge of the Geumbuk Mtns. had a small number of large-sized forest patches. However, cities including Taean, Seosan, Dangjin, Hongseong near the ridge of the western Geumbuk Mtns. had a large number of small-sized forest patches. Finally, this study showed that the region near the coast line in Chung-nam province has various types of forest patches having an irregular forest edge due to the elevation and slope lower than the one of the region far from the coast line which is near the ridge of the Geum-buk Mountains. Remote sensing data were useful to understand the distribution of forest patches, and landscape indices could be keys to delineate the relationship between forest patches. And the factor analysis, which simplified 26 landscape indices into 4 landscape patterns allowed us to understand the distribution and relationship of forest patches in an easy way.

• Journal of the Korean GEO-environmental Society
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• v.25 no.4
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• pp.29-35
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• 2024

This is an analytical study to confirm the passive resistance effect before post-tensioning of steel bar anchors. When using a steel bar as a permanent anchor, if displacement occurs within the slope even before the head load is applied, the displacement is suppressed by the passive resistance caused by the interaction between the steel bar, grout, and surrounding soil. Accordingly, the shape of the failure surface and changes in the safety factor were examined using limit equilibrium analysis and finite element analysis targeting sites where steel bar anchors were actually applied. It was found that the safety factor of the slope reinforced with steel bar anchors is 2.02 using finite element analysis, which is about 5.9% smaller than 2.14 using limit equilibrium analysis. Also, the location of the failure surface was found to be deeper compared to the unreinforced slope. Likewise, the factor of safety has a 153% and 163% increase using finite element method and limit equilibrium analysis, respectively. In addition, the maximum displacement occurs in the lower unreinforced section within the slope, and the displacement is found to be reduced by 42 to 83% at the location where the steel bar anchors are installed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.423-431
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• 2013

The k-factor method has been widely used in design of steel-concrete composite bridges to determine indeterminate stresses. The accuracy of k-factor method is examined by a comparative analysis with the equivalent load method in a continuous 2-span composite bridge. To improve the accuracy, the direction of creep stress has to be modified and the variety of section must be considered. This paper suggests j-factor method which can improve the accuracy of k-factor method with simple modification.

• Journal of Navigation and Port Research
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• v.39 no.5
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• pp.423-429
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• 2015

The expansion on the scale of international trade and rapid economic growth in Northeast Asia have caused intense competition among global companies for securing international logistics center in Northeast Asia. Analyzing location competitiveness for international logistics center in Northeast Asia, this paper aims to extract implications for enhancing locational competitiveness. Employing the relative importance among location selection factors extracted from AHP analysis in prior study, we evaluated the major five port-cities in Northeast Asia including Busan, Gwangyang, Shanghai, Qingdao and Tokyo. In the evaluations, Shanghai (3.926) ranked as the first, followed by Busan (3.859), Qingdao (3.555), Tokyo (3.013) and Gwangyang (2.915). Furthermore, the causal relationships between determinants for location choice decision (logistics factor, cost factor, market factor, service factor and environmental factor) and dependent variables (competitiveness of international logistics center, potentiality to growth, present intention to move into and future plan to move into) were analyzed to provide implications. Results provide useful insights for further improvements, and helps strategic agenda for future development of port-cities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4
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• pp.129-134
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• 1992

This paper presents the relation between risk and safety factor for optimal storm sewer design in urban area. For reliability analysis of the storm sewer, uncertainty of the various parameters of constituting equation determining the capacity and load of storm" sewer is considered and risk is determined. In this study, reliability analysis method is applied to Seongsan detention reservoir basin which area is $381,000m^2$ Darcy-Weisbach equation is used for determining capacity of the storm sewer and rational formula is used for determining load. Safety factor representing ratio of the sewer capacity and design flowrate is calculated, and relating with risk. Then risk and safety factor with return period is obtained and it is used for optimal design of storm sewer.

• Journal of Preventive Medicine and Public Health
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• v.44 no.1
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• pp.41-47
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• 2011

Objectives: This study assessed the factors that have an influence on the residents exposed to heavy metals, and we utilized the findings to establish the proper management of abandoned metal mines in the future. Methods: For a total of 258 residents who lived close to abandoned mines in Gangwon-province and Gyeonggi-province, the exposure factors and biomarkers in their blood and urine were comparatively analyzed via multiple regression analysis. Results: The blood levels of lead and mercury and the cadmium levels in urine were found to be higher in the study group than that in the average Korean. For the blood levels of heavy metals according to each exposure factor, all of them were found to be significantly higher in both of the group residing for a longer period of time and the group living closer to the source of pollutants. Multiple regression analysis disclosed that all the heavy metals, except lead, in their blood were significantly reduced in proportion to the increased distance of inhabitancy from the mines. Their other biomarkers were within the normal ranges. Conclusions: We found that the distance between the residential village and the mines was a factor that affects the blood level of heavy metals in the villagers. This finding could be an important factor when developing a management model for the areas that surround abandoned metal mines. (ED note: I much like this important study.)

• Journal of Environmental Science International
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• v.32 no.8
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• pp.521-531
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• 2023

This study analyzed the impact of recirculation on high-concentration PM_2.5 in the coastal area. Through the analysis of observational data, it was observed that the development of sea breeze led to an increase in PM_2.5 and SO₄^2- concentrations. Hysplit backward trajectory analysis confirmed the occurrence of air mass recirculation. Results from WRF and CMAQ numerical simulations indicated that pollutants transported from land to sea during the night were re-transported to the land by daytime sea breeze, leading to high-concentration PM_2.5 in Busan. To quantitatively investigate the recirculation a recirculation factor (RF) was calculated, showing an increase in RF values during high-concentration PM_2.5 episodes. However, the RF values varied slightly depending on the time resolution of meteorological data used for the calculations. This variation was attributed to the terrain characteristics at observation sites. Additionally, during long-range transported days leading to nationwide high-concentration PM_2.5 events, synoptic-scale circulation dominated, resulting in weaker correlation between PM_2.5 concentration and RF values. This study enhances the understanding of the influence of recirculation on air pollution. However, it is important to consider the impact of temporal resolution and terrain characteristics when using RF for evaluating recirculation during episodes of air pollution.

• Journal of Environmental Science International
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• v.25 no.7
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• pp.963-972
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• 2016

A survey was performed to present a scheme for building a healing forest park inside a city in consideration of the fact that healing forests are located in non-urban areas because of their nature, and are therefore not conveniently accessible to urban population (n=196). As a result, among 196 respondents to the survey, 74.5% indicated that it was necessary to build an urban healing forest park. In the case of the expected usage pattern, were an urban forest park to be built, the largest proportion responded that it would be used to "walk", followed by "rest and meditation" and then "meeting/talk/date". An analysis showed that the largest proportion responded that they factor in "Accessibility" (48%), followed by "Park condition" (16.8%), and "Vegetation type" (12.2%). According to the analysis of usage preference for healing therapy, it was shown that the largest proportion preferred "Terrain therapy" (37.8%), followed by "Exercise therapy" (19.9%), and "Naturopathy" (18.9%). The factor anlaysis of usage preference regarding urban healing forest park facilities showed that the components were divided into "Operation facilities" and "Natural healing space", and the largest proportion preferred "Trails for healing", followed by "Space or forest for meditation" and "Health promotion center", and then "Facilities for a exercise therapy". In building an urban healing forest park, we think that it is effective to introduce zones and facilities in consideration of park characteristics that are centered on everyday behaviors, such as taking a walk, which differ from those of healing forests located in non-urban areas.

• The Journal of Korean Society for School & Community Health Education
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• v.7
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• pp.1-17
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• 2006

Background: School is a primary health education setting for adolescents and the continuous support should be provided to renew school health education curriculum correspondent to cultural changes in Korean society. Objectives: This study was conducted to identify the principals and teachers' health education needs for their students and to analyze their conceptual map for health education curriculum at school. Methods: The sample size of the preliminary study was 321 of the teachers in elementary, middle, and high school, and that of the main study was 355 middle school principals and teachers over the country. The self-administered mailing survey was conducted to collect the available health education topics in the preliminary study, to identify the factor structure of the health education topics and to analyze the conceptual properties on health education with exploratory factor analysis and multidimensional scaling analysis in SPSS 12.0. Results: A total of 21 health education topics were collected from the preliminary survey and 31 topics were, comprehensively, generated for the main survey. In exploratory factor analysis, seven factors were generated in 1.0 or greater Eigen value standard. The seven factors were 'life health promotion,' 'disease prevention and drug control,' 'bulling and aggression prevention,' 'injury and sexual harassment prevention,' human-efficacy and regulation,' 'health protection for adolescence,' and 'alcohol and tobacco control.' The educational need scores were the highest in 'human-efficacy and regulation' and 'injury and sexual harassment prevention.' The two-dimensional cooperates were generated for the 31 health education topics and the two dimensional properties which divided the conceptual space were 'health-safety' for one and 'public/environmental-individual/personal' for the other. That is, middle school principals and teachers primarily, understand the health education curriculum in the sense of 'health vs. safety' and 'public/environmental vs individual/personal.' Conclusions: Health education curriculum and textbook should be developed based on teachers' needs and conditions for health education in school fields. The field-based health education programs or textbook would make more possible problem-solving health education for youth in real school fields.