• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.39-46
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• 2020

Carbonation is a deterioration which degrades structural and material performance by permitting CO₂ and corrosion of embedded steel. Service life evaluation through deterministic method is conventional, however the researches with probabilistic approach on service life considering loading and cold joint effect on carbonation have been performed very limitedly. In this study, probabilistic service life evaluation was carried out through MCS (Monte Carlo Simulation) which adopted random variables such as cover depth, CO₂ diffusion coefficient, exterior CO₂ concentration, and internal carbonatable materials. Probabilistic service life was derived by changing mean value and COV (Coefficient of variation) from 100 % to 300 % and 0.1 ~ 0.2, respectively. From the analysis, maximum reduction ratio (47.7%) and minimum reduction ratio (11.4%) of service life were obtained in cover depth and diffusion coefficient, respectively. In the loading conditions of 30~60% for compressive and tensile stress, GGBFS concrete was effective to reduce cold joint effect on carbonation. In the tensile condition, service life decreased linearly regardless of material types. Additionally service life rapidly decreased due to micro crack propagation in the all cases when 60% loading was considered in compressive condition.

• Journal of radiological science and technology
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• v.28 no.1
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• pp.13-17
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• 2005

In domestic nondestructive testing(NDT) field, there have recently been radiation exposure accidents due to a disregard for confirmation of the position of radioisotope during the test. In order to prevent these kinds of accidents, a scintillating film has been developed. The scintillating film that can convert gamma-ray to visible light has a function of the position detection of radioisotope in a opaque guide tube of an NDT apparatus. The aim of this study is to enhance the visibility performance of the scintillating film and find out the best configuration of the scintillating film. In order to find appropriate materials for the scintillating film, various inorganic scintillating materials were evaluated in this work. An absolute luminance of the scintillating films was measured by luminance meter for evaluation of visibility performance. Ir-192 gamma projector was used for NDT apparatus. The experiment shows that the scintillating film with reflective layer was the more effective performance for visibility. The higher mixing ratio of scintillating material to binding material, the higher luminance was measured. $Gd_2O_2S(Tb)$ inorganic powder as the scintillating materials had the best performance for visibility of the scintillating film. The developed scintillating film helps to ensure safer environment to the operators.

• 보존과학연구
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• s.32
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• pp.25-35
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• 2011

Wood vinegar and Asarum sieboldii Miquel were selected as candidate materials showed antimicrobial activity and insect repellent activity. These natural pesticides have its own color and these could cause color difference on fabric materials. In the present study, we investigated the color difference of undyed and dyed fabrics to evaluate negative effect of wood vinegar and A. sieboldii Miquel. Undyed and dyed fabrics were exposed to natural pesticides of various concentrations for six months in relative humidity 70% and temperature $28^{\circ}C$. After exposure of pesticides, color difference (${\Delta}E*$) were investigated at two weeks intervals for six months. As a results, dyed cotton, silk and undyed silk fabrics exposed wood vinegar were not nearly changed in their colors, but color of only undyed cotton fabric was clearly changed by wood vinegar. Especially color difference by wood vinegar on undyed cotton fabric was most distinct as the concentration increased. On the other hand, all of fabrics exposed A. sieboldii Miquel were not nearly changed in their colors for six months. Therefore, this study first suggests that wood vinegar and A. sieboldii Miquel as natural insecticides could be used to conserve for textile cultural properties from insects and microorganism, but wood vinegar couldn't use the high concentration on undyed cotton fabric.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.17-28
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• 2008

Favorable policies for freight vehicles (i.e., trucks), such as exclusive "Truck-ways," have been proposed, and at the same time restricted policies for freight vehicles have been suggested because transportation of goods by truck aggravates traffic congestion and environmental conditions in urban areas. This study discusses the limitations of assessment processes for freight vehicle route management systems which have been carried out from limited perspectives such as physical distribution efficiency and traffic circulation. The objective of this study is to propose an assessment method of truck route management systems in urban areas which includes more varied criteria. This research modified the two existing assessment indices of physical distribution efficiency and traffic circulation. In addition two new assessment indexes are proposed: (i) exposure indices for population directly influenced by nitrous oxide, a representative pollutant, and (ii) a friction index between trips for attending elementary school and freight vehicle trips. It was found that from the perspective of physical distribution efficiency and traffic circulation, the "before" alternative is better than "after". However, from the aspect of traffic safety and environmental impacts the "after" alternative is better than "before". It is expected that the proposed evaluation method in this study would be useful when identifying reasonable policies for truck route management in urban areas.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.223-231
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• 2014

In order to prevent the spread of non-indigenous aquatic species through the ballast water in commercial ships, International Maritime Organization (IMO) adopted in 2004 the International Convention for Control and Management of Ship's Ballast Water and Sediments. The Convention mandates treatment of ballast water for most transoceanic voyages and its confirmation of treatment is made with plankton live/dead assay. Fluorescein diacetate assay (FDA), which produces bright green light for live phytoplankton, has been a de facto standard method to determine the survival of marine plankton, but its staining efficacy has been in dispute. In the present study, we examined the limitation of FDA, and compared its efficacy with Neutral red (NR) staining, another promising assay and widely used especially for zooplankton mortality. For all phytoplankton species studied in the present study, except Ditylum brightwellii, the staining efficiency was <50% with FDA. The green FDA fluorescence interfered with phytoplankton autofluorescence in most samples. In contrast, NR assay stained over 90% of both phytoplankton and zooplankton species tested in this study. FDA assay also showed that green FDA fluorescence rapidly faded when phytoplankton cells were exposed to microscope light. Both FDA and NR assay were negative on formalin-killed individuals of both phytoplankton and zooplankton species. Our results suggest that NR assay is more effective for determining the survival of marine plankton and can be applied to test the efficacy of ballast water treatment.

• Journal of Science and Technology Studies
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• v.17 no.2
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• pp.173-208
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• 2017

Along with its expertise and yearning for freedom, Science has been seduced from Society. Coupled with societal uncertainty and complexity, the Science has faced the difficulty of solving societal issues and recognized its limitation on the control of quality it has kept. This leads to yield its way for opening up the societal participation. With this situation in mind, this paper explores the ways of societal participation on science based on previous studies but limited to evaluation. While the classical evaluation on science is conducted by only experts and not opened to the public, both the participatory and deliberative evaluation on science are open to the public and fitted to this research subject. Both evaluations are in common to expand its involvement to the broader stakeholder than classical one, but have discrepancy in the perspective of evaluands, evaluation methology applied, scope of participants and role of mediators. Along with the main obstacles such as political acceptance, representative of participants, competency of mediators, epistemic limitation and institutional path-dependency, this paper articulates the ways to implement both evaluations. Last but not least, this paper puts an importance on various and consequent research activities on this domain, reorganizing societal system and weighting efforts.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.49-58
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• 2019

In the era of the 4th industrial revolution, the development of information technology brought various benefits, but it also increased social interest in privacy issues. As the possibility of personal privacy violation by big data increases, academic discussion about privacy management has begun to be active. While the traditional view of privacy has been defined at various levels as the basic human rights, most of the recent research trends are mainly concerned only with the information privacy of online privacy protection. This limited discussion can distort the theoretical concept and the actual perception, making the academic and social consensus of the concept of privacy more difficult. In this study, we analyze the privacy concept that is exposed on the internet based on 12,000 news data of the portal site for the past one year and compare the difference between the theoretical concept and the socially accepted concept. This empirical approach is expected to provide an understanding of the changing concept of privacy and a research direction for the conceptualization of privacy for current situations.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.5
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• pp.901-909
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• 2021

Since mobile devices have limited computational resources, it tends to use the cloud to compute or store data. As real-time becomes more important due to 5G, many studies have been conducted on edge clouds that computes at locations closer to users than central clouds. The farther the user's physical distance from the edge cloud connected to base station is, the slower the network transmits. So applications should be migrated and re-run to nearby edge cloud for smooth service use. We run applications in docker containers, which is independent of the host operating system and has a relatively light images size compared to the virtual machine. Existing migration studies have been experimented by using network simulators. It uses fixed values, so it is different from the results in the real-world environment. In addition, the method of migrating images through shared storage was used, which poses a risk of packet content exposure. In this paper, Containers are migrated with Secure CoPy(SCP) method, a data encryption transmission, by establishing an edge computing environment in a real-world environment. It compares migration time with Network File System, one of the shared storage methods, and analyzes network packets to verify safety.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.617-626
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• 2021

Purpose: The purpose of this study is to evaluate the fire srpead risk of building exterior and roofing materials due to the firebrand of forest fire occurring in the urban areas. Method: In order to achieve this research purpose, by selecting building materials used for exterior and roofing materials of buildings, the time to ignition, total heat release, and heat release rate were investigated, and a forest fire firebrand system was established to the possibility of fire spread was confirmed. Result: As a result of the cone calorimeter test, the roofing material had a similar or faster ignition time due to radiant heat compared to the exterior material with the steel plate exposed to the outside, and showed a higher heat release rate and total heat release than the exterior material. Although it was affected by the flammable material, it was confirmed that it did not spread easily due to the limited amount of combustible material, and carbonization marks appeared inside. Conclusion: The cone calorimeter test method has been shown to be useful in understanding the combustion characteristics of building materials by radiant heat, but the fire spread due to a firebrand in a forest fire is directly affected by the flame due to the ignition of surrounding combustibles, so finding a direct correlation with the cone calorimeter method is difficult. It is judged that the roof material may be more vulnerable to the spread of fire due to the fire than the exterior material.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.317-327
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• 2021

This study is a randomized controlled trial to compare the effects of light therapy on stress, depression, sleep quality and quality of life in middle-aged women. The participants of this study were 56 middle-aged women who worked at the same office. Data collection period was from August 26 to September 13 for the control group and from September 16 to October 4 for the experimental group. Subjective stress, depression, quality of sleep and quality of life in middle-aged women were measured by Numeric Rating Scale (NRS), Center for Epidemiology studies of scale (CES-D), Verran & Synder-Halpern Sleep scale (VHS) and WHO Quality of Life Scale Abbreviated Version (WHOQOL-BREF). Stress index was measured using a Canopy9 RSA (IEMBIO, Gangwondo, Korea) equipment. The data were analyzed by mean, standard deviation, real number and percentage, χ²-test, t-test, repeated measures ANOVA and ANCOVA using IBM SPSS Statistics version 25.0. The results showed that the experimental group applying light therapy had significantly lower subjective stress (F=6.30, p<.001) and higher quality of life (F=2.80, p=.049) than the control group, There was no difference in objective stress index, depression, and sleep quality. As a result, light therapy is partially effective in subjective stress and quality of life for middle-aged women, and further research is needed on middle-aged women working in work environments with limited light exposure.