• Journal of the Korean Society of Safety
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• v.36 no.2
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• pp.87-93
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• 2021

Modern society shows rapid growth that is different from that of the development of existing technologies. The development of these technologies has led to the tendency of buildings to become dense, large and advancing. Regarding fire hazards, the possibility of large-scale fires causing fatal damage, due to the rapid spread of fire, increases. Therefore, for this reason, fire defense, i.e. detection and fire extinguishing facilities, in buildings are essential and well applied. But there are always limitations to that. Based on this reason, we would like to suggest the introduction of a new concept of a fire safety system. The method presented here is not only to use a single system for fire detection and fire extinguishing systems but to jointly use it in the environment and energy management fields within the building. However, an important step is required before introducing a system of these technologies. The fire extinguishing method proposed by this system is a method of extinguishing by blocking oxygen flowing into the space where the fire occurred. However, a sufficient basis is needed for this system to be applied in practice. Therefore, in this study, we intend to conduct a preliminary experiment to introduce the new concept of fire detection and extinguishing. The experiment used ethanol with a relatively simple combustion reaction and a high possibility of complete combustion. As a result, it was confirmed how the internal values changed during a fire using ethanol. Resultingly, we obtained the internal oxygen concentration and internal environmental changes according to the initial flame size. Lastly, the data accumulated in this study can be used as data for application in an automatic fire extinguishing system.

• Advances in nano research
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• v.10 no.2
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• pp.191-210
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• 2021

To compare the antifungal effect of two nanomaterials (NMs), nanoparticles of zinc oxide were synthesized by a chemical route and zinc oxide-based nanobiohybrids were obtained using green synthesis in an extract of garlic (Allium sativum). The techniques of X-Ray Diffraction (XRD), Infrared (IR) and Ultraviolet Visible (UV-Vis) absorption spectroscopies and Scanning (SEM) and Transmission Electron Microscopies (TEM) were used to determine the characteristics of the nanomaterials synthesized. The results showed that the samples obtained were of nanometric size (< 100 nm). To compare their antifungal capacity, their effect on Cercospora sp. was evaluated. Test results showed that both nanomaterials had an antifungal capacity. The nanobiohybrids (green route) gave an inhibition of fungal growth of ~72.4% while with the ZnO-NPs (chemical route), inhibition was ~87.1%. Microstructural studies using High Resolution Optical Microscopy (HROM) and ultra-structural analysis using TEM carried out on the treated strains demonstrated the effect of the nanofungicides on the vegetative and reproductive structures, as well as on their cell wall. To account for the antifungal effect presented by ZnO-NPs and ZnO nanobiohybrids on the fungi tested, effects reported in the literature related to the action of nanomaterials on biological entities were considered. Specifically, we discuss the electrical interaction of the ZnO-NPs with the cell membrane and the biomolecules (proteins) present in the fungi, taking into account the n-type nature of the ZnO semiconductor and the electrical behavior of the fungal cell membrane and that of the proteins that make up the protein crown.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.89-94
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• 2021

Recently, the boundaries between people who produce and consume digital contents disappears due to the massive developments in information and communications technology (ICT) and the rapidly increasing spread of smartphones unlike in the traditional mass media (e.g., newspapers, radios, and TVs). Through the open service platform, the problem perception for each individual remains the same, but the problem solving methods varies as the service types have been diversified. The creation of added value through the growth of the new media platform industry is expected to enrich our lives, but it can also cause severe social side effects. For example, communication problems between social classes due to the information gap have led to generational conflict, and if such problems persist, it can cause national and social losses. Therefore, this paper analyzes the policy efforts to resolve the information gap and the necessity of the legalization of multimedia literary education to maximize the synergy effect through psychological model.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.1
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• pp.45-57
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• 2022

A rash guard, also known as rash vest or rashie, is functional sportswear that protects the wearer's skin from various dangers during outdoor sports activities. It is durable and comfortable since it is designed considering muscle movement. In modern society, more and more people enjoy leisure activities due to an increase in income level and increased leisure hours. Water leisure activities are increasingly enjoyed in the summer. As the way people think of leisure evolves, people are more inclined toward dynamic leisure sports rather than static facility tourism. Therefore, more research on rash guards is required. By identifying and analyzing the design preferences and purchase behaviors of young adults on rash guards, this study aims to provide basic data on the actual sportswear behaviors concerning those who are most active in water sports, people in their 20s and 30s. Furthermore, the study aims to contribute to a healthy exercise lifestyle for women who enjoy water sports and the growth of the water sportswear market. In the study, a survey was conducted using a questionnaire to investigate the wearing behaviors and purchase preferences as well as the wearing satisfaction on rash guards. For the study, 200 copies of the questionnaire were distributed and collected to be used as analysis data. The questionnaire consisted of 36 questions, 6 about demographic characteristics, 11 about purchase preferences, and 19 about wearing satisfaction. The collected data was analyzed using the statistical program SPSS 8.0. The study results can be used as basic data to investigate the design preferences and wearing behaviors of rash guards of women in their 20s and 30s. The results found numerous complaints on comfortableness and durability, which suggests more concern and improvements are necessary in those areas when designing patterns for rash guards.

• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.1972-1981
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• 2022

A typical ferritic/martensitic (F/M) steel sheet was subjected to pulsed laser surface remelting (LSR) and corrosion test in lead-bismuth eutectic (LBE) at 550 ℃. There present two modification zones with distinct microstructures in the LSRed specimen: (1) remelted zone (RZ) consisting of both bulk δ-ferrite grains and martensitic plates and (2) heat-affected zone (HAZ) below the RZ, mainly composed of martensitic plates and high-density precipitates. Martensitic transformation occurs in both the RZ and the HAZ with the Kurdjumov-Sachs and Nishiyama-Wassermann orientation relationships followed concurrently, resulting in scattered orientations and specific misorientation characteristics. Hardnesses of the RZ and the HAZ are 364 ± 7 HV and 451 ± 15 HV, respectively, considerably higher than that of the matrix (267 ± 3 HV). In oxygen-saturated and oxygen-depleted LBE, thicknesses of oxide layers developed on both the as-received and the LSRed specimens increase with prolonging corrosion time (oxide layers always thinner under the oxygen-depleted condition). The corrosion resistance of the LSRed F/M steel in oxygen-saturated LBE is improved, which can be attributed to the grain-refinement accelerated formation of dense Fe-Cr spinel. In oxygen-depleted LBE, the growth of oxide layers is very low with both types of specimens showing similar corrosion resistance.

• Journal of People, Plants, and Environment
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• v.23 no.4
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• pp.399-410
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• 2020

The United Nations project the world population to reach 10 billion by the year 2057. To increase the food of the ever-increasing world population, agrochemicals are indispensable tools to the boon in agriculture production. These agrochemicals are a serious threat to the health of humans, plants, and animals. Agrochemicals are ultimately reached to the main reservoir/sink such as soil and contaminating the groundwater, disturb the soil health and in turn a serious threat to biogeochemical cycling and the entire biosphere. Among agrochemicals, quinalphosis one of the most repeatedly and widely used insecticides in the control of a wide range of pests that attack various crops. Quinalphos is shown to be primarily toxic in organisms by acetylcholinesterase enzyme action. Hydrolysis of quinalphos produces amajor metabolite 2-hydroxyquinoxaline (2-HQ), which has shown secondary toxicity in organisms. 2-HQ is reported to be mutagenic, carcinogenic, growth inhibition and induce oxidative stress in organisms. Quinoline is a heterocyclic compound and structural resemblance of 2-HQ with minor changes, but its degradation studies are enormous compared to the 2-HQ compound. Biotic factors in fate and behavior of 2-HQ in the environment are least studied. 2-HQ interactions with soil enzymes are vary from soil to soil. Based on the toxicity of 2-HQ in our stockpile we need to isolate a handful of microorganisms to treat this persistent metabolite and also other metabolites/compounds.This brief review will be significant from the point of biological and environmental safety.

• Journal of Korea Trade
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• v.24 no.1
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• pp.1-34
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• 2020

Purpose - In this study, we investigate determinants of hedging with derivatives and its effect on firm value and firm risk for Korean firms. Design/methodology - To avoid the endogeneity problem pointed out in previous studies, we use a two-stage analysis by using gains and losses from derivatives as instrument variable for hedging with derivatives. Findings - Our analysis on the determinants of hedging shows that firms that are more leveraged and less profitable, and with more growth opportunities are likely to hedge through derivatives. Additionally, large firms, firms less diversified into industry, and firms more diversified geographically are likely to use derivatives. Our two-stage analysis shows that indicators of hedging with derivatives have an insignificant effect on firm value, and the indicator of futures/forwards use and of swaps use have significant negative effect on firm value. Whereas, the extent of hedging with derivatives has positive effect on firm value for all types of foreign currency derivatives, which suggests that moderately low hedgers use derivatives inefficiently, but extensive hedgers use derivatives properly. With regard to firm risk, hedging with derivatives increases market-based risk, but decreases accounting-based risk. Thus, we conclude that Korean firms use derivatives to manage operational volatility rather than to manage market risk, and accounting-based risk reduction through hedging is not directly translated into higher firm value. Originality/value - This is not the first study to investigate hedging behavior of Korean firms, but the sample period that that this study analyzed is the longest and various method are used to control the endogeneity problem. We investigate not only total foreign currency derivatives but also by types of derivatives, including futures/forwards, options, and swaps.

• Journal of Korea Trade
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• v.25 no.6
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• pp.57-77
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• 2021

Purpose - International strategic alliance has been regarded as a strategic decision made by firms' managerial problems and ensure performance growth. From the perspective of the proactive behavior for changing strategies in a global market, this study aims to identify whether performance feedback influences firms' decisions to pursue strategic alliances. This study examines the effects of performance feedback on performance when firms use strategic alliances. Design/methodology - To analyze the impact of performance feedback on forming an international strategic alliance, this study adopt the concept of performance feedback to develop a research model and our hypotheses. Thus, this study used a two-stage least squares unbalanced panel data analysis with random effects. This study is based on 24,543 observations from Korean manufacturing firms from 2007 to 2016. Findings - The results show that firms pursue the formation of strategic alliances more actively, if their past financial and R&D performance are lower than their aspiration level, based on the result of performance feedback. An in split sample analysis for examining the effect of a firm's technology sophistication based on the OECD's classification, negative innovation performance discrepancy has positive effects on the probability of international alliance in high-tech and medium-high-tech industries. Financial performance also improves when a firm decides to form a strategic alliance based on the results of performance feedback. Originality/value - This research extends recent efforts to better understand the effect of performance feedback on firms' performance when they use strategic alliances. These findings suggest that the CEOs and managers of firms should consider the performance feedback perspective when deciding to pursue a strategic alliance to improve performance. In other words, the decision-makers in a firm must analyze and consider various complex variables inside and outside the firm and expand such subjects of examination to more complex and dynamic factors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4292-4307
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• 2021

For the research field of night infrared surveillance video, the target imaging in the video is easily affected by the light due to the characteristics of the active infrared camera and the classical ViBe algorithm has some problems for moving target extraction because of background misjudgment, noise interference, ghost shadow and so on. Therefore, an improved ViBe algorithm (I-ViBe) for moving target extraction in night infrared surveillance video is proposed in this paper. Firstly, the video frames are sampled and judged by the degree of light influence, and the video frame is divided into three situations: no light change, small light change, and severe light change. Secondly, the ViBe algorithm is extracted the moving target when there is no light change. The segmentation factor of the ViBe algorithm is adaptively changed to reduce the impact of the light on the ViBe algorithm when the light change is small. The moving target is extracted using the region growing algorithm improved by the image entropy in the differential image of the current frame and the background model when the illumination changes drastically. Based on the results of the simulation, the I-ViBe algorithm proposed has better robustness to the influence of illumination. When extracting moving targets at night the I-ViBe algorithm can make target extraction more accurate and provide more effective data for further night behavior recognition and target tracking.

• Structural Engineering and Mechanics
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• v.83 no.4
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• pp.551-561
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• 2022

In this paper, the effect of fire conditions according to ISO 834 standard on the behavior of carbon fibre-reinforced plastic (CFRP) reinforced steel beams coated with gypsum-based mortar has been investigated numerically. To study the efficiency of these beams, 3D coupled temperature-displacement finite element analyzes have been conducted. Mechanical and thermal characteristics of three different parts of composite beams, i.e., steel, CFRP plate, and fireproof coating, were considered as a function of temperature. The interaction between steel and CFRP plate has been simulated employing the adhesion model. The effect of temperature, CFRP plate reinforcement, and the fireproof coating thickness on the deformation of the beams have been analyzed. The results showed that within the first 120 min of fire exposure, increasing the thickness of the fireproof coating from 1 mm to 10 mm reduced the maximum temperature of the outer surface of the steel beam from 380℃ to 270℃. This increase in the thickness of the fireproof layer decreased the rate of growth in the temperature of the steel beam by approximately 30%. Besides excellent thermal resistance and gypsum-based mortar, the studied fireproof coating method could provide better fire resistance for steel structures and thus can be applied to building materials.