• Publications of The Korean Astronomical Society
• /
• v.32 no.1
• /
• pp.193-195
• /
• 2017

We demonstrate the luminosity dependence of the covering factor (CF) of active galactic nuclei (AGNs), based on AKARI mid-infrared all-sky survey catalog. Combining the AKARI with Sloan Digital Sky Survey (SDSS) spectroscopic data, we selected 243 galaxies at $9{\mu}m$ and 255 galaxies at $18{\mu}m$. We then identified 64 AGNs at $9{\mu}m$ and 105 AGNs at $18{\mu}m$ by their optical emission lines. Following that, we estimated the CF as the fraction of type 2 AGN in all AGNs. We found that the CF decreased with increasing $18{\mu}m$ luminosity, regardless of the choice of type 2 AGN classification criteria.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.20 no.4
• /
• pp.34-39
• /
• 2016

Arrhenius kinetic constants, the activation energy and the pre-exponential factor, of energetic material $BKNO_3$ are estimated using Differential Scanning Calorimetry (DSC). Different from the conventional way, the activation energy was estimated more precisely through DSC aging trial, and the consumed fraction by heat was calculated by comparing the integration of heat flow. We suggested the condition of accelerated aging test for the energetic material $BKNO_3$ and reconsidered the meaning of the thermal accelerated aging.

• Korean Journal of Veterinary Research
• /
• v.62 no.1
• /
• pp.4.1-4.5
• /
• 2022

This paper describes a fatal case of pneumonia in a 14-day-old dog caused by extraintestinal pathogenic Escherichia coli (ExPEC). The necropsy showed that almost all of left lobes of the lungs had dark-red consolidation. A histopathology examination revealed moderate acute fibrino-hemorrhagic necrotizing pneumonia with intralesional bacterial colonies. Non-suppurative epicarditis, congestion in the liver, and necrosis in the white pulp of the spleen also were found. E. coli with cytotoxic necrotizing factor 1 and α-hemolysin was isolated from the lung. This case was confirmed to have fatal pneumonia caused by ExPEC that led to a systemic infection.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.17 no.5
• /
• pp.80-85
• /
• 2013

This paper describes a probabilistic structural design method of composite propulsion system by comparing safety factor based on average value and allowable value with structural reliability. Generally, the required structural safety factor and reliability of composite pressure vessel are 1.5 and 0.999, respectively. In the case of structural design using average strength, the safety factor which satisfies the required structural reliability depends on the variation of fiber strength. However, the structural design using allowable value shows constant safety factor for the variation of fiber strength, because the allowable value of fiber strength is calculated by considering the variation of fiber strength. Through the analysis results, it was known that the fiber strength is the most important design random variable for the structural design of composite pressure vessel and the variation of fiber strength must be minimized to develop the high performance composite propulsion system.

• Journal of the Ergonomics Society of Korea
• /
• v.27 no.3
• /
• pp.81-92
• /
• 2008

Musculoskeletal disorder (MSD) problems have been increasingly reported in hospital sector but the problems were not addressed with respect to holistic aspects of the target population in Korea. Often, it is required to understand how MSD symptoms are associated with factors such as personal, work environmental and psychosocial stressors. To examine features of association between sets of MSD symptoms and the factors, a questionnaire survey was conducted in a university hospital. A 140-item questionnaire was developed and used for collecting information including factors (e.g., job/occupation, task/activity, job stress) and MSD symptoms. A total of 1,091 workers (male 23.7% and female 76.3%) were finally determined for data analyses. Prevalence rate for the whole body was 72% and, among body parts, the highest was 48.7% for the shoulder, followed by 34.6%(the low back), 32.7%(the leg/foot), 27.9%(the neck), 26.7%(the wrist) and 12%(the elbow). The symptoms were significantly different by job/occupational variable in each of all body parts except the neck. The symptoms were very significantly different by task/activity variables in each of all body parts while those symptoms were significantly different by psychosocial variables, depending on body part and gender. In the logistic regression analyses performed for MSD symptoms by body part and each of 3 factors, odds ratio values varied, ranging from 0.7 to 3.3. The controls for reducing the symptoms were discussed on the basis of the findings. The results show that the MSD symptoms can remarkably vary by the factors and, in particular, can be highly differential for the task/activity factor. This study suggests that MSD symptom features be examined by using various factors and then a higher differential factor be primarily utilized for controling MSD symptoms in general industry including hospital settings.

• Journal of Radiation Protection and Research
• /
• v.47 no.2
• /
• pp.77-85
• /
• 2022

Background: After the Fukushima Daiichi Nuclear Power Station (FDNPS) accident, a model was developed to estimate the external exposure doses for residents who were expected to return to their homes after evacuation orders were lifted. However, the model's accuracy and uncertainties in parameters used to estimate external doses have not been evaluated. Materials and Methods: The model estimates effective doses based on the integrated ambient dose equivalent (H^*(10)) and life patterns, considering a dose reduction factor to estimate the indoor H^*(10) and a conversion factor from H^*(10) to the effective dose. Because personal dose equivalent (H_p(10)) has been reported to agree well with the effective dose after the FDNPS accident, this study validates the model's accuracy by comparing the estimated effective doses with H_p(10). The H_p(10) and life pattern data were collected for 36 adult participants who lived or worked near the FDNPS in 2019. Results and Discussion: The estimated effective doses correlated significantly with H_p(10); however, the estimated effective doses were lower than H_p(10) for indoor sites. A comparison with the measured indoor H^*(10) showed that the estimated indoor H^*(10) was not underestimated. However, the H_p(10) to H^*(10) ratio indoors, which corresponds to the practical conversion factor from H^*(10) to the effective dose, was significantly larger than the same ratio outdoors, meaning that the conversion factor of 0.6 is not appropriate for indoors due to the changes in irradiation geometry and gamma spectra. This could have led to a lower effective dose than H_p(10). Conclusion: The estimated effective doses correlated significantly with H_p(10), demonstrating the model's applicability for effective dose estimation. However, the lower value of the effective dose indoors could be because the conversion factor did not reflect the actual environment.

• Journal of Ocean Engineering and Technology
• /
• v.25 no.1
• /
• pp.67-72
• /
• 2011

Offshore structures, such as a platform, a buoy, or a floating vessel, are exposed to several dynamic loads, and viscoelastic damping material is used to reduce the vibration of offshore structures. It is important to know the properties of viscoelastic materials because loss factor and Young's modulus of the viscoelastic damping material are dependent on frequency and temperature. In this study, an advanced technique for obtaining accurate loss factor and Young's modulus of the viscoelastic damping material is introduced based on a multi degree of freedom curve-fitting method and the RKU (Ross-Kerwin-Ungar) equations. The technique is based on a modified experimental procedure from ASTM E 756-04. Loss factor and Young's modulus of the viscoelastic damping material are measured for different temperatures by performing the test in a temperature-controlled vibration measurement room where temperature varies from 5 to 45 degrees Celsius.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.8
• /
• pp.678-685
• /
• 2017

The radiator of the data storage and handling units onboard the earth observation satellite is a groove-type radiator covered with a shield because of the periodic high heat dissipation and design characteristics of arrangement and mountability of the unit. The effect of the groove-type radiator and that of the shield versus plane radiator were verified through the thermal vacuum test. Through the test result, the temperatures of the radiator and the heat exchange due to the view factor were analyzed by using the analytical method. Conclusively the thermal performance of the shield dissipation plate was verified.

• The Korean Journal of Rehabilitation Nursing
• /
• v.4 no.2
• /
• pp.137-145
• /
• 2001

This study examined and identified the relationship between the level of hope and self-care agency in hemodialysis patients. The purpose of the study was to reveal that hope is an essential factor to enhance self-care agency and to prepare the basic materials to help nurse the patients. The subjects for this study consisted of 108 persons who undergoing hemodialysis from 2 hospital, 2 hemodialysis center in Pusan, Korea. The degree of hope was measured by the questionnaire that has been developed by Miller. The self-care agency was measured by the questionnaire that has been developed by Kearney B.Y & Fleisher B.J. The collected data were analyzed by descriptive statistics and t-test. one-way ANOVA and Pearson's Correlation Coefficient with SPSS WIN program. Results were obtained as follows: 1) The mean scores of hope were $131.77{\pm}25.77$(range 67-195). The rate of hope classified said that the lowest hope was 2.8% and low hope was 27.8%. 2) The mean scores of self-care agency were $143.78{\pm}23.63$(range 74-187). The degree of self-care agency classified said that the rate of self-care agency deficiency was 0.9% and low self-care agency was 12.0%. 3) The hope was significantly related to self-care agency. That is, the higher the hope score was， the higher the level of self-care agency score(r=0.668，p=0.001) was. In this result, there were hemodialysis patients who have very low hope score and self-care agency score. In this cases self-care agency can be increased by encouraging the patients to be more hopeful. Conclusively nurses should access the degree of hope and self-care agency of hemodialysis patients individually and apply the hope therapy in order that the patient have higher hope than before.

• International Journal of Advanced Culture Technology
• /
• v.7 no.1
• /
• pp.150-154
• /
• 2019

The purpose of this research is to identify major factors that influence the cognition the elderly in community. There was a significant correlation between the cognitive and visual perceptual skills of the elderly. The subject's cognitive skill was statistically higher for males by gender, for lower age group, and for higher level of education.