• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.484-492
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• 2018

This study examined the effects of field complexity and type of target objects on the performance in baggage screening task. A total of 62 participants(male: 45.2%, female: 54.8%) participated and their mean age was 22.88. The simulated baggage screening task was developed for this study and after the orientation and task exercises, main experiment session was conducted. Participants performed a total of 200 tasks and 40(20%) contained target object. The complexity was set at three levels: high, middle, and low levels and the number of background items contained 20, 14. and 8 respectively. The type of target was set as gun, knife, liquid, and righter. The dependent variables were hit ratio and reaction time. The results showed that the hit ratio decreased and reaction time increased significantly as field complexity increased, and they varied depending on the type of target. The hit ratio of the knife was the highest and liquid lowest and reaction time of the knife was the fastest and liquid slowest. In addition, the interaction effect was also significant. Knife was not affected by complexity, however, small item such as lighter was most affected by complexity.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.12
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• pp.1930-1938
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• 2018

Objective: The present study attempted to determine safe and sufficient growth promoters in poultry feeding. Methods: A total of 520 seven-day-old quail chicks were randomly allotted to eight treatment groups in a $4{\times}2$ factorial design experiment to evaluate the effect of different levels of humic acid (HA) and black cumin (BC) seed and their interactions on growth, carcass traits, gut microbes, and blood chemistry of growing quails. Quails were randomly distributed into 8 groups in a $4{\times}2$ factorial design, included 4 HA levels (0, 0.75, 1.5, and 2.25 g/kg diet) and 2 BC levels (0 or 5 g/ kg diet). Results: Increasing HA level associated with a gradual increase in final weight, feed intake and body weight gain along with an improvement in feed conversion ratio. Dietary addition of 5 g BC powder/kg diet gave similar results. The highest level of HA (2.25 g/kg diet) recorded the best values of carcass weight, breast yield, intestinal length, and intestinal weight comparing with the control and other HA levels. Total viable microbial counts decreased (p<0.05) with increasing levels of HA except the intermediate level (1.5 g/kg diet). The concentration of serum cholesterol and low density lipoprotein (excluding that 0.75 g HA) decreased (p<0.05) and high density lipoprotein increased (p = 0.034) along with increasing HA level. The interaction between the $2.25g\;HA{\times}5g$ gave the best results regarding most studied parameters. Conclusion: These findings indicated that HA combined with BC could be used as effective growth promoters, with the recommended level being 2.25 g HA+5 g BC/kg of quail diet.

• 한국노년학
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• v.37 no.3
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• pp.583-600
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• 2017

The purpose of this study is to explore qualitatively what kind of coping strategy the Korean older adults use when they are depressed and why. Participants were users, older than 60, of an elderly welfare center in Seoul, and answers of 34 respondents who experienced depression were included in the analysis. The collected data were analyzed through content analysis. The results of the analysis showed that strategies to cope with depression used by participants were composed of 6 domains and 11 sub-domains: health behavior (medical approach / exercise and diet), family and social contact (social interaction / going out and going on a trip / communication with family), Religious activities (Religious activities), lifelong education (hobbies / educational activities), productive activities (labor), health risk behaviors (drinking and gambling / resignation). The depression coping strategies of the older adults and their characteristics are as follows. First, older adults used diverse problem-focused coping strategies to cope with depression. Second, older adults considered various coping strategies together and used them simultaneously. Third, the facility space for older adults functions as a shelter. Fourth, although there were cases where medical approach was used, the intention to reuse was very low. Through this study, the following suggestions were made to help older adults cope with depression more successfully. First, access to various coping strategies should be promoted. Second, more places where older adults can spend their time comfortably need to be provided. Third, resistance to mental health care should be resolved.

• 한국노년학
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• v.38 no.1
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• pp.187-202
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• 2018

The purpose of this study was to examine the effects of the middle-aged Korean's experience discriminated level on the acts of discrimination against the elderly, and moderating effect of the awareness of social status of the aged. The subjects were 509 middle-aged(40-54 years old) from the Korean General Social Survey(KGSS)(2011). This study applied descriptive analyses, correlation analysis and multi-regression with STATA14. The results showed that the level of discrimination against the elderly was 2.20points(5 points), and awareness of elderly's social status was 2.45 points (4 points). Middle-aged Korean's experience discriminated was 0.74. The results of multiple regression analysis showed that discriminatory experiences affect positively on discrimination against the elderly. However, the awareness of elderly' social status had a negative interaction effect on the relationship between discriminatory experiences and discrimination against the elderly. Discrimination against the elderly was increased when the level of experience of discrimination was high and the social status of the aged was low. Based on the results, this study suggested practical and political opinions for reducing Discrimination against the elderly.

• Korean Journal of Psychosomatic Medicine
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• v.26 no.2
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• pp.194-200
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• 2018

Objectives : The significance of leukoaraiosis on brain magnetic resonance imaging (MRI) is uncertain, but it is often seen with vascular risk factors or in the context of cognitive impairment. We aimed to investigate the effect of leukoaraiosis on the severity and course of delirium. Methods : Periventricular hyperintensity and deep white matter hyperintensity on brain MRI were rated in 42 patients with delirium by semiquantative visual rating scale. Correlations between their grades and the scores of Korean version of Delirium Rating Scale-Revised-98 (K-DRS-R-98) were analyzed, and the interaction effects between the groups according to the levels of leukoaraiosis and two evaluation points were also analyzed. Results : The grade of deep white matter hyperintensity in the occipital lobe was positively correlated with the scores on the total, severity items, cognitive items, and non-cognitive items of K-DRS-R-98. The cognitive items scores of K-DRS-R-98 in the low grade group of periventricular hyperintensity showed significantly steeper decrease than the high grade group. Conclusions : A difference in severity or recovery speed of delirium according to the level of leukoaraiosis may result from disruption in brain functional connectivity. Our results have a clinical implication in that the severity and course of delirium can be possibly predicted using the level of leukoaraiosis.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.345-353
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• 2018

Hibernation is regarded as a physiological and behavioral adaptation that permits the survival of animals such as bats during seasonal periods of energy shortage. This study investigated the hibernation period of Plecotus ognevi in the temperate climate zone and the relationship between the thermal preference and hibernating process of bats. We hypothesized that the hibernation period of bats is closely related to the external temperature and temperature preference of bat species in the temperate region. To verify this hypothesis, we surveyed the distribution of the P. ognevi population in South Korea, and the temperature preference and the characteristics of hibernacula of P. ognevi. We predict that hibernation in the bat will begin when the external temperature drops below the thermal preference of the species and will leave from hibernation when the external temperature is higher than the thermal preference. P. ognevi hibernated in roosts maintained in low temperature ambient conditions with $-3.5{\sim}7.5^{\circ}C$). The body temperatures (averaged $3.01{\pm}1.30^{\circ}C$, ranged $0.1{\sim}7.8^{\circ}C$) of hibernating bats were closely related to the rock surface temperatures rather than the ambient temperatures. The bats began to hibernate in late November and final arousals occurred in mid-March, so that the total length of the hibernation was 115~120 days. The period of hibernation was strongly influenced by fluctuations in the external mean temperature. This study suggests that the onset and termination of P. ognevi hibernation is due to the interaction between the temperature of the hibernacula and that of the external environment and is based on the thermal preference of the bats. The study also suggests that the hibernation strategy such as thermal preference and hibernation periods of this species affect to distribution as bat species adapting to a severely climate.

• The Journal of the Acoustical Society of Korea
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• v.38 no.4
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• pp.378-386
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• 2019

Unlike ship noise that radiates from moving ships, wind noise is caused by breaking waves as a result of the interaction between the wind and the sea surface. In this paper, WNL (Wind Noise Level) was modeled by considering the noise source of the wind as the bubble cloud generated by the breaking waves. In the modeling, SL( Source Level) of the wind noise was calculated using the wind-speed data measured from the weather buoy operated in the coastal area of the East Sea. At the same time as observing the wind speed, NL (Noise Level) was continuously measured using a self-recording hydrophone deployed near the weather buoy. The modeled WNL according to the wind speed and the measured NL removing the shipping noise from the acoustic raw data were compared in the low-frequency band. The overall trends between the modeled WNL and the measured NL were similar to each other. Therefore, it was confirmed that it is possible to model the WNL in the shallow water considering the SL and distribution depth of bubble cloud caused by the wind.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.278-280
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• 2019

Flow cytometer is one of the instrument that can measure various optical properties of a single cell or microparticle. These parameters including size, granularity, and fluorescence intensity are determined by the physical and optical interaction of the cells with excitation light source. However, users have some difficulties such as high cost, size of instrument, and limited fluorescence selectivity. In addition, abundant data is also unintentionally acquired even though user wants to have a single optical parameter. For these reasons, the use of flow cytometer is more challenging for researchers to apply their study. Therefore, the proposed study aims to develop a low-cost portable fluorescence acquisition system using a commercially available light-emitting diode and photodiode. It is designed by a 3D printer, and fluorescence selectivities are increased by changing of the light source / optical filter / detection sensor. Various number sets of fluorescently labeled cells were measured, and its feasibility was evaluated through the proposed system. As a result, acquried fluorescence intensities were proportional to the concentration of the cells and showed high linearity.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.690-701
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• 2021

This study examines the effects of job stress on fire-fighters' job performance on negative job factors, job burnout, and positive job factors, job satisfaction, respectively, and by examining whether resilience has a modulating effect in these influence relationships. This was done to provide useful information for planning management strategies. The analysis was done by regression analysis of data collected through a structured survey of 239 fire-fighters, and the moderating effect was confirmed by calculating and applying the interaction term. For the analysis, a structured questionnaire survey was conducted on 239 fire-fighters. As a result of the analysis, it was confirmed that job stress and job burnout of fire-fighters were low, job satisfaction was normal, and resilience was above average. Also, there was no significant difference in resilience according to demographic characteristics, and it was found that job stress had a positive(+) influence on job burnout at a statistically meaningful level, and a negative(-) influence on job satisfaction. In addition, it was found that impulse control power and cause analysis power had a moderating effect in the influence relationship between job stress and job burnout, and impulse control power had a moderating effect in the influence relationship between job stress and job satisfaction. Based on these results, it was proposed to preemptively apply various resilience programs suitable for the situation of fire-fighters, enhance emotional competence, and introduce coaching personnel to help self-reflection.

• Tunnel and Underground Space
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• v.30 no.6
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• pp.573-590
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• 2020

This study presents the current status of DECOVALEX-2023 project Task G and our research results so far. Task G, named 'Safety ImplicAtions of Fluid Flow, Shear, Thermal and Reaction Processes within Crystalline Rock Fracture NETworks (SAFENET)' aims at developing a numerical method to simulate the fracture creation and propagation, and the coupled thermohydro-mechanical processes in fracture in crystalline rocks. The first research step of Task G is a benchmark simulation, which is designed for research teams to make their modelling codes more robust and verify whether the models can represent an analytical solution for displacements of a single rock fracture. We reproduced the mechanical behavior of rock and embedded single fracture using a three-dimensional grain-based distinct element model for the simulations. In this method, the structure of the rock was represented by an assembly of rigid tetrahedral grains moving independently of each other, and the mechanical interactions at the grains and their contacts were calculated using 3DEC. The simulation results revealed that the stresses induced along the embedded fracture in the model were relatively low compared to those calculated by stress analysis due to stress redistribution and constrained fracture displacements. The fracture normal and shear displacements of the numerical model showed good agreement with the analytical solutions. The numerical model will be enhanced by continuing collaboration and interaction with other research teams of DECOVALEX-2023 Task G and validated using various experiments in a further study.