• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.255-266
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• 1999

The objective of this experiment is to observe the elastic and inelastic behaviors of high-rise reinforced concrete frames having non-seismic details. To do this, a building frame designed according to Korean seismic code and detailed in the Korean conventional practice was selected. A 1:12 scale plane frame model was manufactured according to similitude law. A reversed lateral load test and a monotonic pushover test were performed under the displacement control. To simulate the earthquake effects, the lateral force distribution was maintained to be an inverse triangle by using a whiffle tree. From the tests, base shears, crack pattern, local rotations in the ends of critical members and the relations between interstory drift versus story shear are obtained. Based on test results, conclusions are drawn on the implications of the elastic and inelastic behaviors of a high-rise reinforced concrete frame having non-seismic details.

• Tunnel and Underground Space
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• v.14 no.4
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• pp.269-274
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• 2004

In this study reduced-scale experiments were conducted to determine the backlayering distance in tunnel fires. The 1/20 scale experiments were carried out under the Froude scaling using ethanol square pool fire ranging from 8 to 1km in each side with total heat release rate from 2.47 to 12.30 ㎾. It has been found that ventilation velocity increases with aspect ratio(tunnel height/tunnel width). At L$\_$B/$\^$*/ ＜5 the ventilation velocity increases proportional to the backlayering distance from 0.25 power of the heat release rate. However at L$\_$B/$\^$*/ $\geq$5 the ventilation velocity varies as the 0.3 power of the heat release rate.

• Journal of computational fluids engineering
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• v.19 no.2
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• pp.99-107
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• 2014

The aim of the present study is to investigate the flow interference between two adjacent undulating fish-like body, and its effect on the undulating propulsion. For this purpose, unsteady two dimensional incompressible flow calculations were conducted using an unstructured mesh flow solver, coupled with an overset mesh technique. To deal with mesh deformation due to fish locomotion, spring analogy is utilized. The fish body used in the simulation is constructed from the NACA0012 airfoil. The study indicates that the propulsion of undulating fish is proportional to frequency and wavelength of the midline oscillation when there is no adjacent fish. It also reveals that average thrust was increased when the vortex shedding from the tail was conserved well and pressure difference between upper and lower sides of the fish was magnified due to flow interference. From this study, which relative position and phase difference of locomotion between two fishes can generate maximum thrust was known among six different cases.

• Journal of computational fluids engineering
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• v.18 no.3
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• pp.26-33
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• 2013

In the present study, unsteady flow simulations of a variable geometry nozzle were conducted using a two-dimensional flow solver based on hybrid unstructured meshes. The variable geometry nozzle is used to achieve efficient performances of aircraft engines at various operating conditions. To describe the motion of the variable geometry nozzle, an algebraic method based on the basis decomposition of normal edge vector was used for the deformation of viscous elements. A ball-vertex spring analogy was used for inviscid elements. The aerodynamic data were obtained for a range of nozzle pressure ratios, and the validations were made by comparing the present results with available experimental data. The unsteady nozzle flows were simulated with an oscillating diverging section and a converging-diverging section. It was found that the nozzle performances are influenced by the nozzle exit flow characteristics, mass flow rate, as well as unsteady effects. These unsteady effects are shown to behave differently depending on the frequency of the nozzle motion.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.149-152
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• 2010

It was investigated that effect of the supersonic impulse turbine rotor leading edge thickness which was the part of 75 ton open cycle liquid rocket engine turbopump. The test for turbine was performed that the rotor thickness to pitch ratio was 1.9 and 1.4 to 30 ton turbine. As a result of test, the rotor with lower thickness(1.4) had 1.5% efficiency gain to the higher thickness(1.9) and the pressure ratio with maximum efficiency was increased to the nozzle full expansion point.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.206-216
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• 2007

The purpose of this paper is to examine the relationship between job satisfaction and organizational commitment according to employment types. As a result of this study, firstly, while there is a significant difference in the job itself satisfaction between regular and contingent workers, there is no significant difference in the organizational commitment between regular and contingent workers. Concretely, a job itself satisfaction degree is higher in contingent workers rather than in regular ones, and the level of organizational commitment is no difference between regular and contingent workers. Secondly, there is no moderating effect according to employment types in job satisfaction influencing on organizational commitment. In addition, there is a partially difference in the job satisfaction factor having influence on regular and contingent workers' organizational commitment. That is, it is confirmed that the satisfaction of job itself in regular workers has influence on organizational commitment positively, and the satisfaction of job itself, promotion, and supervisor in contingent workers has influence on organizational commitment positively.

• Journal of Industrial Convergence
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• v.21 no.5
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• pp.31-41
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• 2023

We examine the relationship between abusive supervision and work-family conflict, and the moderating effects of employee's resilience and perceived organizational support. We collected the employees' sample(n=136) and conducted multiple hierarchical regression analysis. Abusive supervision has a significant positive effect on work-family conflict. Subordinate's resilience has a buffer effect on the main relationship, but perceived organizational support has no significant moderating effect. This study will be helpful for employees who are suffered from work-family conflict.

• Journal of Korea Port Economic Association
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• v.39 no.1
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• pp.65-100
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• 2023

This study examines the effects of organizational trust of the container terminal operators' employee on organizational citizenship behavior and the moderating effect of organizational support in the relationship between the two variables. In order to efficiently achieve the purpose of this study, an empirical analysis was conducted by distributing a literature review and a questionnaire, and the results of the study are as follows... First, the organizational trust of the container terminal operators' employee was found to have a significant positive (+) effect on organizational citizenship behavior, and trust in the company appeared to be more important than trust in the superior, indicating trust in the institutional aspect. This means that formation has more influence on organizational citizenship behavior... Second, it was confirmed that the organizational support of the container terminal operators' employee can lead to active participation in organizational citizenship behavior through the expansion of educational compensatory support. Third, among the organizational support of container terminal operators, emotional support and educational compensatory support were found to have a partial moderating effect on the relationship between organizational trust and organizational citizenship behavior." Emotional support has a moderating effect on caring and active participation behaviors in the relationship between trust in the company and organizational citizenship behaviors, and a moderating effect on caring, active participation, and non-complaining behaviors in the relationship between trust in superiors and organizational citizenship behaviors. It was analyzed that there is Compensatory educational support has a moderating effect on altruistic, caring, active participation, and non-complaining behavior in the relationship between trust in the company and organizational citizenship behavior. It was analyzed that there was a moderating effect on active participation and non-complaining behavior. These analysis results mean that members' trust in the company further increases through the container terminal operator's emotional support and educational reward support. As uncertainty grows, it is very important to increase the trust of organizational members in the organization. sense of belonging to the organization, Emotional support that can increase immersion, improvement of work environment, provision of educational opportunities, and education-compensatory support such as a fair compensation system will increase organizational trust and induce effective organizational citizenship behavior to realize sustainable growth of the organization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1759-1768
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• 2012

The present study was intended to measure the level of fatigue symptoms among nurses working for a university hospital and to reveal its related factors. The self-administered questionnaires were given to 450 nurses during the period from October 1st to 31st, 2010. As a results, the level of fatigue symptoms were 75.1% in normal group, and the high-risk group 24.9%. The level of fatigue symptoms reflected in job stress contents were higher as job demand was higher, and the autonomy of job and the supervisor support was lower. In correlations, fatigue symptoms were found to be in a positive correlation with job demand, whereas in negative correlation with autonomy of job and supervisor support. The adjusted odds ratio of fatigue symptoms on job demand were significantly increased in the high risk group than in low group, but autonomy of job. were significantly decreased in the high risk group than in low group. In conclusion, the study results indicated that the level of fatigue symptoms is independently influenced by job stress contents.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.496-506
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• 2021

This study examined the relationship between job stress and fatigue symptom of fire-fighting officials. The study subjects were 330 fire-fighting officials working at five fire stations in the D metropolitan city. The study survey was a structured self-administered questionnaire from September 1 to October 31, 2019. The level of fatigue symptoms and job stress were significantly higher (p<.0.001). By the sub-region, the level of fatigue symptoms and job demand were significantly higher (p=0.046), but the decision latitude, the supervisor support, and co-worker support were lower (p=0.006, p<0.001, and p<0.001, respectively). The level of fatigue symptom showed a significant positive correlation with the total score of job stress (r=0.348, p<0.05) and the job demand (r=0.301, p<0.05). In contrast, it showed a significant negative correlation with the decision latitude (r=-0.306, p<0.05), supervisor support (r=-0.340, p<0.05), and co-worker support (r=-0.355, p<0.05). Multivariate logistic regression showed that the odds ratio of the high-risk fatigue group was significantly higher in the high-risk group of job stress than in the low group of job stress (ORs=3.03, 95% CI=1.13~8.12). These findings suggest that the level of fatigue symptoms of fire-fighting officials is related significantly to job stress.