• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.153-161
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• 2014

The purpose of this study is to evaluate effect of heavy metals (i.e., $Cu^{2+}$, $Zn^{2+}$, $Cr^{6+}$, $Cd^{2+}$, $Hg^{2+}$, and $Pb^{2+}$) to toxicity of Triclosan as binary mixture. The individual toxicity and combined toxic effects of Triclosan with heavy metals were evaluated by Vibrio fischeri assay. In individual toxicity, the $Hg^{2+}$ was found to be most toxic followed by Triclosan, $Pb^{2+}$, $Cr^{6+}$, $Cu^{2+}$, $Zn^{2+}$, and $Cd^{2+}$, respectively. To evaluate combined toxic effect, correlation analysis of 'predicted value' calculated by Concentration addition (CA) model and Independent action (IA) model with 'experimental value' were performed based on the toxicity of individual compound. As a result, all of the combinations showed that IA model were more correlated with experimental value than CA model. On the basis of the median effect concentration of combination ($EC_{50mix}$) predicted by IA model, experimental $EC_{50mix}$ of Triclosan + Cu, Triclosan + Zn, Triclosan + Pb, Triclosan + Hg, Triclosan + Cd, and Triclosan + Cr were 191%, 226%, 138%, 137%, 209%, and 138% of $EC_{50mix}$ predicted by IA model, respectively, indicating that all of the combinations produced antagonistic effect.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.4
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• pp.366-374
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• 2013

Maritime transportation circumstance is changing rapidly in accordance with the increase of cargo volume between countries and increase of marine leisure activities by improvement of quality of life. And the circumstance for ship operation is also changing due to aging of seafarers and increasing of foreign seafarers. To cope with such changes in maritime environment well, it requires higher safety management skills from shipping companies, the main subject in charge of the safety matter. In this paper, we analyzed domestic and foreign similar system, and then applied imitation strategies for introduction of an unific evaluation and management system that was consist of marine accidents, port state control, ISM Code and so on from shipping companies. We defined that the imitation industry and system are converted accident ration of construction industry and traffic safety excellence company of road transportation, and then extracted relevant law, evaluation index, incentive system as a imitation subject. We also proposed scheme that introduction of basis law, and evaluation tool with marine accidents ratio, port state control & ism code result, and incentives such as immunity of safety inspection or reduction of commission for introduction of company's safety management level evaluation system. Finally, we proposed the imitation timing and plan in stages for system's sustainable development through the prompt introduction and continuous enforcement.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.250-256
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• 2013

Gasoline generates organic acid and polymer (gum) by hydrocarbon oxidation depending on the storage environment such as temperature and exposure to sunlight, which can cause metal corrosion, rubber and resin degradation and vehicle malfunction caused by accumulation in fuel supply system. The gasoline which has not been used for a long time in bi-fuel (LPG-Gasoline) vehicle causes problems, and low octane number gasoline have evaporated into the field, but the exact cause has not been studied yet. In this study, we suggest a plan of quality management by investigating the gasoline oxidation behavior. In order to investigate the oxidation behavior of gasoline, changes of gasoline properties were analyzed at various storage conditions such as storage time, storage vessel type (vehicle fuel tank, PE vessel and Fe vessel) and storage circumstances (sunlight exposure and open system, etc.). Currently distributing gasoline and bioethanol blended fuel (blended 10%) were stored for 18 weeks in summer season. The sample stored in PE vessel was out of quality standard (octane number, vapor pressure, etc.) due to the evaporation of the high octane number and low boiling point components through the vessel cap and surface. Especially, the sunlight exposure sample stored in PE vessel showed rapid decrease of vapor pressure and increase of gum. Bioethanol blended fuel showed similar results as gasoline.

• Spatial Information Research
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• v.20 no.2
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• pp.155-164
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• 2012

Indoor fire simulators have been used to analyse building safety in the events of emergency evacuation. These applications are primarily focused on simulating evacuation behaviors for the purpose of checking building structural problems in normal time rather than in real time situations. Therefore, they have limitations in handling real-time evacuation events with the following reasons. First, the existing models mostly experiment the artificial situations using randomly generated evacuees while real world requires actual data. Second, they take too long time in operation to generate real time data. Third, they do not produce optimal results to be used in rescueing or evacuation guidance. In order to solve these limitations, we suggest a method to build an evacuation simulation system that can be used in real-world emergency situations. The system performs numerous simulations in advance according to varying distributions of occupants. Then the resulting data are stored in DBMS. The actual person data captured in infrared sensor network are compared with the simulation data in DBMS and the querried data most closely is provided to the user. The developed system is tested using a campus building and the suggested processes are illustrated.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.457-465
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• 2008

Eight Bacillus thuringiensis strains activated against mosquito larva were compared their characterization. Spherical-shaped parasporal inclusion of B. thuringiensis subsp. tohokuensis CAB167 was observed by phase-contrast microscopy and scanning electron microscopy. $LC_{50}$ values of B. thuringiensis subsp. tohokuensis CAB167 against Culex pipiens molestus, Culex pipiens pallens, and Aedes aegyti were 173, 190 and 580 ng/ml, respectively. B. thuringiensis subsp. tohokuensis CAB167 had a parasporal inclusion containing 4 major protein components, for example, 135, 80, 49 and 28-kDa by SDS-PAGE. Otherwise, after trypsin digestion of parasporal inclusion, SDS-PAGE was showed new protease-resistant peptides at 72 and 63-kDa. Activated toxins of isolated CAB167 were different from other reference strains on a serological by immuno-diffusion test.

• Journal of Korean Society of Forest Science
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• v.83 no.1
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• pp.20-24
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• 1994

In woody species with a long life span, the studies on inheritance of any trait may be very time consuming and laborious. Chloroplast DNA(cpDNA) has been a valuable tool in such studies since it has several unique features such as limited genome size and cytoplasmic inheritance. In the present study, cpDNAs from five different species of Populus(P. alba, P. glandulosa, P. alba${\times}$P. glandulosa, P. davidiana, and P. nigra), and Nicotiana tabacum were compared with regard to restriction fragment length polymophism. The results showed that cpDNAs among the species were very conserved, although some polymorphisms were observed when the DNAs were digested with restriction enzyme EcoRI or KphI. The other enzymes (Bgl II, and PstI) tested produced identical restriction fragmentation pattern among the species. However, cpDNAs from all the five Populus species showed different restriction fragmentation pattern from that of tobacco with the four restriction enzymes tested. Southern hybridization with tobacco rbcL gene fragment as a probe also produced identical pattern among Populus species. The results indicate that cpDNAs in the genus are very well conserved during evolution.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.3
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• pp.179-189
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• 2014

Pyroprocessing has been developed for the purpose of resolving the current spent nuclear fuel management issue and enhancing the recycle of valuable resources. An electrolytic reduction of the pyroprocessing is a process to reduce oxides into metals using LiCl as an electrolyte and requires a post-treatment process due to the inclusion of residual salt in porous metal products. A vacuum distillation has been adopted for various molten salt systems and could be applied to the post-treatment process of the electrolytic reduction. The residual salt in the metal products includes LiCl, alkali chlorides, and alkaline earth chlorides. In this paper, vapor pressures of chlorides have been estimated and the composition changes on the residual liquid during the vacuum distillation process have been calculated. A model combining a material balance and vapor-liquid equilibrium relations has been proposed under a constant vapor discharging flow rate and liquid composition changes have been calculated using the vapor pressures with respect to a dimensionless time. The behaviors have been compared with temperature and molten salt composition changes to simulate the process condition variation. The distillation of the residual salt has been dominated by LiCl which is the main component of the salt and CsCl of which vapor pressure is higher than that of LiCl would be readily removed. RbCl exhibits similar vapor pressure with LiCl and maintains its composition. However, $SrCl_2$ and $BaCl_2$ of which vapor pressures are much lower than that of LiCl are concentrated with time and expected to be possibly precipitated during the distillation when the initial compositions are increased.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.35-42
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• 2017

Previously, we reported LVH peptiede derived from Aurelia aurita as cosmecetuticals with anti-winkle activity. In this study, we synthesized pal-LVH using palmitic acid to enhance skin permeability of LVH and examined the effects as cosmeceuticals of pal-LVH. To evaluate these effects, we performed cell toxicity, wound healing, and patch test for skin irritation with LVH and pal-LVH and compared these results for their effects. As a result. pal-LVH was not showed in cytotoxicity and allergenic effect like as LVH. Besides, pal-LVH had almost same excellent anti-ageing properties in high concentration and anti-winkle effect in low concentrationwas as LVH. These results suggested synthesis of palimitic acid and LVH did not affect any functions as cosmeceuticals with increasing skin permeability. Therefore, pal-LVH can be adaptable as new cosmecetuticals with anti-winkle and anti-ageing materials and applied in the development of medicine through various convergence study.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.2
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• pp.170-179
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• 2017

The purpose of this study was to compare the cariogenicity of commercially available bovine milk and low-fat milk in a biofilm model using the CDC Biofilm Reactor. Streptococcus mutans ATCC 25175 biofilms were formed on saliva coated bovine enamel slabs in a CDC Biofilm Reactor. Biofilms were exposed three times per day to one of the following materials: commercial whole milk (fat content: 3.4%), low-fat milk (fat content: 1%), or 0.9% NaCl. Medium pH was measured at different time points. After 5 days, biofilms were separated from slabs to evaluate the CFUs. The biofilm thickness was observed by confocal laser-scanning microscopy (CLSM). Enamel slab's demineralization was assessed by measuring surface microhardness before and after the experiment. For microhardness and CFUs assessment, no significant difference was found among the three groups. All groups showed similar pattern of medium pH change and biofilm thickness. Our results showed that there was no difference in the cariogenicity between whole milk and low-fat milk. Both milks were relatively non-cariogenic compared to the control group.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.693-705
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• 2016

The purposes of this study were to develop work-life balance supportive organizational culture scale(WLB supportive organizational culture) and to verify it's validity. We reviewed comprehensive studies about work-life balance and organizational culture as well as scales related to them. We theoretically extracted some important factors of WLB organizational culture from reviews and then made 38 preliminary questions. 773 married workers in their 30s to 50s were responded to a questionnaire consisted of 38 preliminary questions and 9 variables(work-life balance, quality of life, job satisfaction, turnover etc) for criterion related validity verification. As the results of factor analysis such as EFA and CFA, we could confirm five factors including WLB organizational management, WLB supportive supervisors, empathetic communication with coworkers, coworkers' material support to WLB and accessibility to WLB programs. Second, correlation analyses were performed to investigate the validation of this scale. In result, it was revealed that the WLB supportive organizational culture scale was highly correlated with other family supportive organizational culture measures as well as dependent variables such as work-life balance, quality of life, job satisfaction, turnover. We expect this study contribute to improve the quality of studies about work-life balance and organizational culture.