• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.1
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• pp.20-31
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• 2005

In this study, subsonic flutter analyses have been conducted for a composite smart UAV with T-tail configuration at the critical flight condition. Detailed three-dimensional finite element model for dynamic analysis is constructed including its nonstructural elements corresponding to installed electronic equipments and fuels. Computational structural dynamics and aeroelastic techniques are conducted using MSC/NASTRAN and originally developed in-house codes. The results for fundamental vibration characteristics and flutter instabilities are presented and compared to each other for different fuel conditions.

• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.51-58
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• 2000

Recently, the J/T analysis based on elastic-plastic finite element analysis is popularly used in the nuclear industry to assess the integrity of a cracked pipe. The objective of this paper is to evaluate the effect of stress-strain curve for weld metal, variation of crack incremental length(${\delta}a$), and crack face pressure on the J/T analysis result. For this purpose, a parametric analysis was performed and the results calculated from finite element analysis were compared with those from the piping experimental data(stainless steel weldment pipe with circumferential through-wall crack). The numerical result using base metal material property is in agreement with the experimental one and the maximum load is decreased as the ${\delta}a$ for J/T analysis is increased.

• Progress in Superconductivity
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• v.6 no.1
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• pp.89-94
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• 2004

The policrystalline$SmBa_2$$Cu_2$$O_{y}$ was synthesized by the solid state reaction method. The dependence of AC susceptibility on temperature and applied ac field was studied. The critical temperature $T_{c}$ is about 92 K. As the ac field is increased, the slope and the value of real part of susceptibility become smaller and the peak position of imaginary part $T_{P}$ was shifted to a lower temperature with peak broadening. Using Bean's model, we determined intergrain critical current density $J_{c}$ and obtained $44 A/{cm}^2$ at 75 K. From the relation of the $J_{c}$ (T)=($1-T/T_{c}$ )$^{\beta}$ we obtained $\beta$=0.8 and found that the Josephson junction type of the $SmBa_2$$Cu_2$$O_{y}$ is SIS junction. The peak of the imaginary part shifts to higher temperature with increasing frequency, f. from Arrhenius plot, we obtained the activation energy of about 0.96 eV.

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.67-84
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• 2008

Objective : The main purpose of this study was to evaluate the effect of Jasinwhalhyul-tang (Zishenhuoxue-tang, JWT) on MRL/MpJ-Ipr/Ipr mouse model with systemic lupus erythematosus. Methods: The effect of JWT on MRL/MpJ-Ipr/Ipr mice that have autoimmune disease similar to SLE in humans was evaluated after JWT per oral in the present study. Mice were administered with Jasinwhalhyul-tang (Zishenhuoxue-tang, JWT) (80 or 400mg/kg) or distilled water for control group from experimental week 10 for 22 weeks. Results : The amount of erythematosus skin lesion and proteinuria were significantly decreased. The size and weight of cervical lymph nodes and spleen were significantly reduced. The ratio between activated $CD3^+CD69^+$ T-cells and undifferentiated $CD3^+CD4^-CD8^-$ T-cells in lymph nodes, spleen and kidney was effectively reduced. The gene expression of TGF-$\beta$ in spleen and kidney was increased. The amount of anti-dsDNA IgG in blood was decreased. The gene expression of TGF-$\beta$ in normal mouse spleen cells was increased depending on concentration by treatment of with T cell stimulating agent. In the histological examination of skin and kidney, the amount of infiltration of immune cells involved in the inflammatory response was decreased. Conclusions : According to the above results, JWT should be considered as an applicable therapeutic agent to SLE in clinical practice. Further research is required to investigate other efficacies of JWT on SLE.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.270-273
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• 2009

This work describes a method of determining material parameters included in recrystallization and grain growth models. Focus is on the recrystallization and grain growth models of Ni-Fe base superalloy, Alloy 718. High temperature compression tests at different strain, strain rate and temperature conditions were chosen to determine the material parameters of dynamic recrystallization model. The critical strain and dynamically recrystallized grain size and fraction at various process variables were quantitated with the microstructual analysis and strain-stress relationships of the compression tests. Besides, isothermal heat treatments were utilized to fit the material constants included in the grain growth model. Verification of the determined material parameters is carried out by comparing the measured data obtained from other compression tests.

• Journal of ILASS-Korea
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• v.22 no.2
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• pp.47-54
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• 2017

$CO_2$ emission regulation will be prescribed and main issue in automotive industry. Mostly, vehicle's fuel efficiency deeply related to $CO_2$ emission is regulated by qualified driving test cycle by using chassis dynamometer and exhaust gas analyser. But, real driving fuel consumption rate depends so much on the individual usage profile and where it is being driven: city traffic, road conditions. In this study, vehicle model of fuel consumption rate for ICEV and PHEV was developed through co-simulation with CRUISE model and Simulink based on driving control model. The simulation results of fuel consumption rate were analysed with on-road vehicle data and compared with its official level.

• The Korean Nurse
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• v.35 no.3
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• pp.61-76
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• 1996

The purpose of this study was to develop a nursing care delivery system which can provide patient focused care and increase satisfaction for both patients and nurses. This study was a quasi-experimental study to test the effectiveness of direct / indirect nursing care hours, patient satisfaction, nurse's job satisfaction, and the difference of the length of stay between model and control group. Control group data were collected from 100 patients who had lumbar disease in the neuro-surgical unit and model group data were from 66 patients who didn't have family residents from August 21, 1995 to February 29, 1996. Model unit was operated by modified PPM(Professional Practical Model) system for 3 months from December 1, 1995 to February 29, 1996. Working committee empowered nurses to make a decision to provide increased opportunities for autonomy, accountability, and control over the environment in which they deliver care. Satisfaction survey was done twice and analyzed by the SPSS program. The results of the study were as follows; 1. Mean direct nursing care hours of the model group was 90.47 minutes as it was 28.04 in the control group which shows significant statistical difference (t=-18.0, P=0.000). 2. Patient satisfaction to nursing care of in the model group was significantly higher than the control group (t=-6. 77, P=0.000) and it apples to the all subcategories, too. 3. Nurse's job satisfaction shows the significant increase in the model group than the control group(Z=-3.0405, p=0.0024). 4. There was no statistical difference between 2 groups in average length of stay except for the post-op patient which shows 5.4 days less in the model group. This study shows that patient satisfaction and nurse's job satisfaction were increased and length of stay was decreased in the model group. Even though this new developed Patient - Nurse Oriented Model can provide nursing with the opportunity to improve patient care to increase productivity and highly valued, it is very difficult to practice due to the limited nursing resources, higher acuity levels and nursing care cost. It is strongly recommended that the government needs to look at the unreasonable reimbursement system and recognize the nursing care costs to the high acuity level patients. Otherwise, make the patient responsible for the nursing care cost so that we can provide more efficient and patient focused care.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.804-811
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• 2021

The T-junction exists widely in industrial engineering, especially in nuclear power plants, which plays an important part in nuclear power reactor thermal-hydraulics. However, the existing prediction models of the liquid entrainment are mainly based on the small branches or small breaks while there are a few researches for large branches (d/D > 0.2). Referring to the classical models about the onset of liquid entrainment of the T-junction, most of previous models regard liquid as ideal working fluid and ignore surface tension. This paper aims to study the effect of surface tension on the liquid entrainment, and develops an improved model based on the reasonable assumption. The establishment of new model employs the methods of force analysis, dimensional analysis. Besides, the dimensionless Weber number is adopted innovatively into the model to show the effect of surface tension. What is more, in order to validate the new model, three kinds of working fluids with different surface tensions are creatively adopted in the experiments: water, silicone oil and ethyl alcohol. The final results show that surface tension has a nonnegligible effect on the onset of liquid entrainment in large branch T-junction. The new model is well matched with the experimental data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.275-276
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• 2009

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1737-1744
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• 2009

This study calculated the relative importance between evaluation factors of websites focused on culture and tourism in J region by 3C_D_T evaluation model of website. That is, this paper was analyzed by AHP (analytic hierarchy process) and calculated the relative weights and preference. In conclusion, this study showed that content was the most important factor and proposed the improvement planning through sensitivity analysis.