• Structural Engineering and Mechanics
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• v.14 no.5
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• pp.565-574
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• 2002

This paper presents a method for predicting premature separation of carbon fiber reinforced plastic (CFRP) plates from strengthened steel beams. The fracture criterion based on material-induced singularity is formulated in terms of a singular intensity factor. Static test on double strap joints was selected to provide the critical stress intensity factor in the criterion because good degree of accuracy and consistency of experimental data can be expected compared with the unsymmetrically loaded single lap joints. The debond/separation loads of steel beams with different CFRP lengths were measured and compared with those predicted from the criterion. Good agreement between the test results and the prediction was found.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.80-89
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• 2011

In service science, it is critical to measure service satisfaction for innovating service processes, which is challenging for service sectors oriented to the usage of IT systems. For that purpose, in this study, a model based on the technology acceptance model and satisfaction measurement model is proposed. The model is empirically tested using data sets from a public service sector (G2B) and a private service sector (internet banking). The purpose of this study is to identify factors which affect the service satisfaction. The result shows that a public service sector is less sensitive to the IT systems on which its services are operated, and that the attitude factor strongly affects the service satisfaction in both sectors.

• BMB Reports
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• v.47 no.7
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• pp.405-410
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• 2014

ZBTB3 belongs to the Zinc finger and BTB/POZ domain containing transcription factor family; however, its biological role has rarely been studied. We demonstrate for the first time, to our knowledge, that ZBTB3 is an essential factor for cancer cell growth via the regulation of the ROS detoxification pathway. Suppression of ZBTB3 using two different short hairpin RNAs in human melanoma, lung carcinoma, and breast carcinoma results in diminished cell growth. In addition, we found that suppression of ZBTB3 activates a caspase cascade, including caspase-9, -3, and PARP leading to cellular apoptosis, resulting from failed ROS detoxification. We identified that ZBTB3 plays an important role in the gene expression of ROS detoxification enzymes. Our results reveal that ZBTB3 may play a critical role in cancer cell growth via the ROS detoxification system. Therefore, therapeutic strategies that target ZBTB3 could be used in selective cancer treatments.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.59-63
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• 2014

Smoke is one of the most critical factor when escaping from the fire since it reduces visibility and interrupts finding emergency exit lights. Therefore, it is recommended that an evacuation simulation program should incorporate the smoke factor. In addition, it is suggested that the program should include not only the unilateral damage by the smoke but also the detour evacuation by risk communication. In this study, MAS (Multi Agent System)-based simulation program which incorporates the reduced walking speed by smoke and adopts the dispersion evacuation logic during escaping from the fire. To make comparison, a commercial evacuation program, Pathfinder was used. It was found that the simulation results of MAS (Multi Agent System)-based program is better than Pathfinder in terms of safe evacuation. It means that evacuation simulation need a additional evaluation categories that include not only quick evacuation time but also safe evacuee number.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.492-497
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• 2006

This study gives the results of the measurements and analysises of the reverberation times in a small room such as apartment houses. We measured the RT by changing measurement conditions, which were sound sources. sound source's positions, receiving point & height, sampling time and so on. The critical factor affecting reverberation time was sound source in unoccupied houses and the reverberation time differences between result of RT using impulsive and interrupted sound source was 0.3sec at 500Hz frequency. And the difference of RT due to sound sources affected the sound insulation such as apparent sound reduction index and sound level difference about 1dB at each frequency in unoccupied houses.

• Tuberculosis and Respiratory Diseases
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• v.83 no.1
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• pp.81-88
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• 2020

Background: Use of appropriate antibiotics for the treatment of pneumonia is integral in patients admitted to intensive care units (ICUs). Although it is recommended that empirical treatment regimens should be based on the local distribution of pathogens in patients with suspected hospital-acquired pneumonia, few studies observe patients admitted to ICUs with nursing home-acquired pneumonia (NHAP). We found factors associated with the use of inappropriate antibiotics in patients with pneumonia admitted to the ICU via the emergency room (ER). Methods: We performed a retrospective cohort study of 83 pneumonia patients with confirmed causative bacteria admitted to ICUs via ER March 2015-May 2017. We compared clinical parameters, between patients who received appropriate or inappropriate antibiotics using the Mann-Whitney U, Pearson's chi-square, and Fisher's exact tests. We investigated independent factors associated with inappropriate antibiotic use in patients using multivariate logistic regression. Results: Among 83 patients, 30 patients (36.1%) received inappropriate antibiotics. NHAP patients were more frequently treated with inappropriate antibiotics than with appropriate antibiotics (47.2% vs. 96.7%, p<0.001). Methicillin-resistant Staphylococcus aureus was more frequently isolated from individuals in the inappropriate antibiotics-treated group than in the appropriate antibiotics-treated group (7.5% vs. 70.0%, p<0.001). In multivariate analysis, NHAP was independently associated with the use of inappropriate antibiotics in patients with pneumonia admitted to the ICU via ER. Conclusion: NHAP is a risk factor associated with the use of inappropriate antibiotics in patients with pneumonia admitted to the ICU via the ER.

• Journal of Korean Critical Care Nursing
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• v.12 no.2
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• pp.1-12
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• 2019

Purpose : The purpose of this study was to validate the Korean version of Partners In Health scale (PIH-K) which is used to measure the self-management of patients with chronic illnesses in Korea. Methods : Translation of the 12-item PIH-K was conducted according to the World Health Organization guidelines. Data from 306 participants who took medicines over 3 months by doctor's prescription were collected from October to November 2017. Validity such as content validity, construct validity, and concurrent validity were conducted using content validity index (CVI), exploratory and confirmatory factor analyses (CFA). To evaluate concurrent validity, the correlation coefficients between the PIH-K and concurrent scales (Self-As-Carer Inventory) were calculated. The reliability of the PIH-K was examined using the internal consistency and test-retest reliability tests. Results : The CVI of the PIH-K was 0.91. According to the CFA, factor loadings for four factors ranged from .64 to .97, which explained 67.5% of the total variance. The PIH-K was significantly correlated with concurrent variables such as those on the Self-As-Carer Inventory. The Cronbach's ${\alpha}$ was .86 and the intraclass correlation coefficient for the two-week test-retest reliability was .88. Conclusion : Findings show that the PIH-K is reliable and valid in measuring self-management of patients with chronic illnesses.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.4
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• pp.31-39
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• 2001

Composite propeller shafts for a vehicle have major advantages such as reduction of vibration, noise, and weight. A propeller shaft was designed with a carbon/epoxy composite material using the finite element method(FEM), and prototype shafts for tests were manufactured by the filament winding manufacturing process. In order to verify the design procedure by FEM, Two kinds of experimental tests were carried out using a FFT analyzer with impact hammers and a critical speed measuring apparatus for measurement of natural frequencies and critical speeds. The difference between the FEM analysis result and the test result was less than 3.4%, showing FEM analysis results to be acceptable. The parametric study was focused on determining the factor affecting the vibration and strength characteristics of the propeller shaft based on FEM. In investigation of the change in natural frequency without an increase in propeller shaft weight, it was found that the winding angle is the most significant factor affecting the vibration and strength characteristics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1185-1191
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• 2010

Aged aircraft have several cracks as a results of long-term service, and these cracks affect the safety and decrease the rate of operation of the aircraft. To solve these problems, crack propagation analysis should be performed to determine the service life at fatigue critical location(FCL). It is, however, almost impossible to obtain the stress spectrum, which is crucial for crack propagation analysis of the FCLs of wing structure of aged aircraft. In this study, to analyze the fatigue crack propagation behavior at the FCL of an aged aircraft, first finite element analysis is performed for a 3D geometry model of the aircraft wing structure, which is obtained using CATIA based on the paper drawings. Then, the transfer function and stress-spectrum of the FCL are derived using the load factor data and the FEA results. Finally, the crack propagation rates of the FCL are evaluated using the commercial software, NASGRO 6.0.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.237-244
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• 1995

Fracture properties for LEFM, S-FPZ and NS-FPZ models were determined using by finite element method and energy balance from the experimental results of three-point bend tests. For the LEFM model the stress intensity factor needed to increase continuously with crack extension, and for the S-FPZ model the fracture process zone characteristics need to change continuously if the critical stress intensity factor was to remain constant. The LEFM model showed the largest resistance and the slowest crack extension, while the NS-FPZ model showed the smallest resistance and the fastest crack extension. The responses for the S-FPZ model were intermediate between those for the LEFM and NS-FPZ models and the total fracture energy densities for the S-FPZ and NS-FPZ models and the total fracture energy densities for the S-FPZ and NS-FPZ models were equal.