• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.59-63
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• 2000

At military bases, environmental restoration activities resulting from oil contamination are growing concerns of preventing adverse effects on human health and environments. Its technologies are still under developing stage through some countries such as United States and Germany. This study is focused on developing model for a decision-maker to assist the restoration priority under the situation of limited resources such as budget and time. The Model, named the Base Restoration Priority Decision model(BRP model), is composed of the three factors : oil contaminants receptors, and the potential migration pathways. Each risk rating of factor is combined in the 27 matrix blocks and set immediate, moderate, and delayed action category designated restoration priority. This is categorized to group sites into three degree using the simplest of assessment system. As a result, the model will be able to apply to the effective allocation of resources for the restoration by any decision-maker because the model is easy to understand. Also, the continuous study will have established risk assessment system for the restoration of contaminated military with this study as the starting point.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.345-353
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• 2018

This study examined the associations of smoking, alcohol drinking habits and both with the carotid intima-media thickness (CIMT) in university students. This study was performed using a CAGE (test for alcohol: cutting down, annoyance by criticism, guilty feeling, and eye-openers) questionnaire, FTND (the Fagerstrom test for nicotine dependence) questionnaire, and CIMT of university students. No statistically significant differences were observed among the CIMT results according to each CAGE level classified into 3 groups. The results of CIMT according to the FTND smoking categorization showed that the smoking group was higher than nonsmoking group (P<0.01). A statistically significant difference was observed between the left and right CIMT regarding smoking and drinking (P<0.01). In the only drink risk group, the left CIMT (19.84 rank) showed a low-ranking. The CIMT on the left (42.38 rank) and right (42.81 rank) showed high scores in the group with only the risk of smoking (P<0.01). These results suggested that there are distinct differences in CIMT and relevant risk factors between smokers and drinkers, particularly among those with a high smoking status. This study had several limitations: the study population was small; the relatively young age of the study subjects; and limited of focus on smoking, drinking and CIMT. In conclusion, cigarette smoking significantly exacerbates the adverse effects and higher CIMT on the subclinical atherosclerosis risk in young adults, which underscores the importance of prevention and cessation of cigarette smoking in young adults.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.3
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• pp.132-137
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• 2008

The average concentrations of COD and copper in the livestock sludge are $930,726{\pm}380.801$ mg/kg and $679{\pm}341$ mg/kg, respectively. Due to the high concentrations, dumping to the sea of the sludge could pose potential adverse effects to the marine environment. On the contrary, it could have economic advantages on land as the energy of biogas generated by decomposition of organisms and the compost in case of the sludge of good quality with the abundant nitrogen and phosphorus. Nevertheless, the amount of livestock sludge dumped to the sea in Korea increased sharply from 51,000 $m^3$ in 1997 to 2,745,000 $m^3$ in 2005. And also it had the high proportion of 27% in total amount of waste dumped into the sea (7,451,000 $m^3$) in 2007. It might cost between 20,000 won and 33,000 won to dump to the sea of the sludge. In comparison, it might cost 20,000 won to com- post the sludge. And its purification treatment even might cost just 10,000 won. It means that the disposal of the sludge at sea is the most expensive method to deal with the sludge, but ranchers, who engage in the livestock industry, still prefer the disposal at sea to the other methods on land such as the compost and purification treatment. In this article, therefore, we would analyze various factors in the ranchers' preference for the disposal of the sludge at sea, and then we could suggest some legal improvements to prevent and reduce pollution of the sea.

• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.189-201
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• 1999

Lead (Pb) is ubiquitous in the urban environment and is a well-known toxic element. It may cause adverse health effects on hematopoietic system, peripheral and central nervous systems, kidney functions, and others. In recent decades, lead concentration in blood has been widely used one of indicators for lead exposure and risk evaluation. In this study, we determined the blood-lead levels in general populations of Korea, and investigated the relationship among blood-lead levels, sociobehavioral factors, and lead concentrations in the contacted environments such as ambient air, drinking water, and foods. The study subjects consisted of volunteers who had lived in the residential or industrial area in Korea. Information about gender, age, living area, occupation, smoking, heat system, and dietary habits, etc was collected using a self-reported questionnaires. The lead concentrations of environments were collected by literature search to the study area. Participated subjects in industrial area were 726 and their blood-lead levels were 8.58 $\mu\textrm{g}$/dl for males and 6.26 $\mu\textrm{g}$/dl for female in average. The other subjects in residential area were 317 and their blood-lead levels were 4.58 $\mu\textrm{g}$/dl for males and 3.49 $\mu\textrm{g}$/dl for female in average. The distribution of blood-lead level in the industrial subjects was well fitted to the log -normal distribution and that in the residential subjects was well fitted to the normal distribution. Blood-lead levels in both area were affected by gender, smoking habit, age and residence duration except age in industrial area and residence duration in residential area. It was identified that 30% of blood-lead level was contributed from the inhalation of ambient air in the industrial area, and 8.4% of blood-lead level was from that in the residential area. from this study, it would be suggested for the health risk assessment and management of lead pollution concerns in urban, industrial and rural areas.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.2
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• pp.211-221
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• 2012

The Ministry of Environment will enforce air quality standards for $PM_{2.5}$ in 2015 because it affects human health as well as climate change and brings about other adverse effects. Until recently, even though a number of researches have reported $PM_{2.5}$ emissions according to sources, they have not precisely considered the emission factors correspondent to each source for emission estimation. For the sake of establishing $PM_{2.5}$ emission inventories, this study was undertaken using activity data of each source taken from CAPSS (Clean Air Policy Support System) multiplied by each emission factor of U.S. EPA Speciate or EEA CORINAIR. The 2008's total annual $PM_{2.5}$ emission (73.971 ton/yr) can be apportioned into five sources, such as fuel combustion facilities (62.2%), mobiles (33.8%), production processes (3.2%), fires (0.4%), and waste treatments (0.3%). The results show that fuel combustion facilities and mobiles are the predominant sources of $PM_{2.5}$, and they should be taken into great account in establishing $PM_{2.5}$ standards. In addition, it is necessary and urgent to develop effective measures for reduction of $PM_{2.5}$ emissions from those two main sources as well.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.448-460
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• 2020

The purpose of this study is to examine the effects of negative experiences on social capital in order to see if the adverse functions of social media could be a barrier to the promotion of social capital through the use of social media. The study verified the moderating effect of perceived performance from social media and negative experiences(victim experience and offender experience) on social capital. The online survey was conducted in November 2019, and a total of 846 responses were used for the final analysis. As a result of the two-step regression analysis using the mean-centering technique first, it was found that the victim experience had no significant effect on the bridge social capital, but the perceived performance and the victim experience had negative moderating effect on the bridge social capital. Second, the victim experience showed a significant positive effect on the binding social capital, but showed a negative moderating effect with the perceived performance indicating positive influence on the binding social capital of the perceived performance could reduce through victim experience. Accordingly it is necessary to educate social media users on the cyber ethics, and regulation is required to mitigate risk factors for trust.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.4.1-4.10
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• 2019

Background: The mandibular third molar (M3) is typically the last permanent tooth to erupt because of insufficient space and thick soft tissues covering its surface. Problems such as alveolar bone loss, development of a periodontal pocket, exposure of cementum, gingival recession, and dental caries can be found in the adjacent second molars (M2) following M3 extraction. The specific aims of the study were to assess the amount and rate of bone regeneration on the distal surface of M2 and to evaluate the aspects of bone regeneration in terms of varying degree of impaction. Methods: Four series of panoramic radiographic images were obtained from the selected cases, including images from the first visit, immediately after extraction, 6 weeks, and 6 months after extraction. ImageJ software^® (NIH, USA) was used to measure linear distance from the region of interest to the distal root of the adjacent M2. Radiographic infrabony defect (RID) values were calculated from the measured radiographic bone height and cementoenamel junction with distortion compensation. Repeated measures of analysis of variance and one-way analysis of variance were conducted to analyze the statistical significant difference between RID and time, and a Spearman correlation test was conducted to assess the relationship between Pederson's difficulty index (DI) and RID. Results: A large RID (> 6 mm) can be reduced gradually and consistently over time. More than half of the samples recovered nearly to their normal healthy condition (RID ≤ 3 mm) by the 6-month follow-up. DI affected the first 6 weeks of post-extraction period and only showed a significant positive correlation with respect to the difference between baseline and final RID. Conclusions: Additional treatments on M2 for a minimum of 6 months after an M3 extraction could be recommended. Although DI may affect bone regeneration during the early healing period, further study is required to elucidate any possible factors associated with the healing process. The DI does not cause any long-term adverse effects on bone regeneration after surgical extraction.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.167-178
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• 2014

As large-scale housing sites are being developed rapidly in Sejong City, which was launched in 2012 for resolving the adverse effects of overconcentration in the capital area, promoting balanced development of the country, and reinforcing national competitiveness, changes in spatial structure are expected in the surrounding areas. For setting the directions of urban planning, it is essential to understand changes in spatial structure. This study purposed to measure changes in the spatial structure of neighboring areas resulting from the construction of Sejong City by approaching from the aspect of spatial interaction. In the analysis, we calculated population potential for future spatial interaction using the accessibility model, and interpreted quantitatively and qualitatively the outcomes of spatial interaction among neighboring areas before and after the construction of Sejong City using population potential as an indicator. According to the results of the analysis, the impact range of the population potential of the subject areas had been shrinking continuously since 1995, and in 2013 population potential dispersed as the population concentrated on and around Cheonan City. Although Sejong City, as a new area of population potential, was not found to play the role of a pivotal point for the surrounding areas, it is probably because the analysis was made just after people began to move to Sejong City. Accordingly, along with the effort of Sejong City to reach the planned population, it is necessary to keep monitoring changes in related factors and changes in the spatial structure of the surrounding cities resulting from the growth of population.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.4
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• pp.333-343
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• 2004

Statement of problem: In its preceding work, change in surface characteristics were investigated in consideration that both microtopograpy and macroscopic configuration of implants surface are two of the most important factors, in that they can construct agreeable environment by raising surface energy, to affect osseointegration and biocompatibility explained by cell proliferation. Purpose: This study focused on examining cytocompatibility of dental implants materials Ti-Ag alloys, of which mechanical and electrochemical superiority to cp-Ti or Ti6Al4V were verified, in comparison with that of cp-Ti, and Ti6Al4V. Materials and methods: In this regard, MTT tests for L-929, the fibroblast connective tissues and cell proliferation tests for osteoprogenitor cells, MC3T3-E1 were performed on cp-Ti, Ti6Al4V, and Ti-Ag alloys following thermal oxidation according to appropriate heat treatment temperature(untreated, 400, 600, $800^{\circ}C$) and heat treatment duration(untreated, 0.5, 1, 4 hr). Results: The MTT tests on fibroblasts L-929 resulted in cell viability of over 90% in all experimental group entities, where, especially, the 100% of the viability for Ti-Ag alloys specimens accounted for the slightest adverse effect of ions release from those alloys on the cell. In MC3T3-E1 proliferation tests, the population of cells in the experimental group was roughly increased as experimentation proceeded, after two to four days. Proliferation showed highest viability for most of specimens, including Ti2.0Ag, treated at $600^{\circ}C$. Conclusion: In conclusion, it is the heat treatment temperature, not the duration that has considerable effects on thermal oxidation of specimens. Ti-Ag alloys treated at $600^{\circ}C$ proved to have the best surface morphology as well as cytocompatibility when compared with Ti or Ti6Al4V for short-term biocompatibility tests.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.1
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• pp.35-42
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• 2015

Purpose: The present study was aimed to compare the difference in adherence level of microorganisms according to contact lens materials and protein deposition and to evaluate disinfection efficacy of multipurpose solution. Methods: The evaluations of micro-organisms' adherence and disinfection efficacy of multi-purpose solution were conducted by employing the Part 2. Regimen Procedure for Disinfecting Regiments in the Disinfection Efficacy Testing under the "FDA Evaluation Criteria & Method". Results: Pseudomonas aeruginosa, Serratia marcescens, Candida albicans except Staphylococcus aureus adhered more on etafilcon A lens and disinfection efficacy of total 4 products investigated was almost perfect except Candida albicans. The 3 micro-organisms except Serratia marcescens adhered more to albumin-predeposited lens. Disinfection efficacy of multi-purpose solution was higher against the micro-organisms adhered to albumin-deposited lens than against the micro-organisms adhered to the lysozyme-deposited lens. Furthermore, disinfection efficacy of multi-purpose solution was different according to types of micro-organisms. Conclusions: It was revealed that the type of micro-organisms, the lens materials and type of absorbed tear protein affected the amount of adhered micro-organisms to contact lens and that adhesion of tear protein could induce the change of disinfection efficacy of multi-purpose solution. It suggest that the hygienic condition of contact lens can vary by these factors influencing on disinfection efficacy and the occurrence of adverse effect can be affected.