• Journal of Pharmaceutical Investigation
• /
• v.36 no.1
• /
• pp.19-22
• /
• 2006

The pharmacokinetics of nimodipine, following a single 16 mg/kg oral dose, was investigated in rabbits with hepatic failure induced by 0.5 mL/kg (mild), 1.0 mL/kg (moderate) and 2.0 mL/kg (severe) of carbon tetrachloride $(CCl_{4}$ : olive oil = 20 : 80, v/v). The plasma concentrations of nimodipine were determined by a high performance liquid chromatographic assay. The levels of sGOT and sGPT in rabbits with mild $(86.2{\pm}29.0\;and\;98.5{\pm}33.1\;unit/dL)$, moderate $(168.1{\pm}61.2\;and\;196.2{\pm}66.0\;unit/dL)$ and severe $(292.7{\pm}82.2\;and\;314.2{\pm}99.8\;unit/dL)$ hepatic failure were significantly increased compared to the control $(38.0{\pm}10.1\;and\;32.4{\pm}10.2\;unit/dL)$. The area under the plasma concentration-time curve (AUC) of nimodipine was significantly increased in mild $(131.7{\pm}28.1%)$, moderate $(168.8{\pm}32.8%)$ and severe $(204.6{\pm}58.3%)$ carbon tetrachloride-induced hepatic failure rabbits compared to the control (100%) rabbits. The volume of distribution $(V_{d})$ and the total body clearance $(CL_{t})$ of nimodipine were significantly decreased in all hepatic failure groups. The elimination rate constant $(K_{el})$ of nimodipine was significantly decreased in moderate and severe carbon tetrachloride-induced hepatic failure rabbits. There was a correlation between sGOT (y= 1.01x+241, r=0.993) or sGPT (y=0.92x +243, r=0.997) value and the AUC of nimodipine in the rabbits with hepatic failure. These findings suggest that the hepatic metabolism of nimodipine was inhibited by carbon tetrachloride-induced hepatic failure rabbits, resulting in the decrese in $V_{d}$ and $CL_{t}$ of nimodipine in the rabbits with mild, moderate and severe hepatic failure.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.34 no.5
• /
• pp.319-325
• /
• 2021

The 2011 East Japan Earthquake caused accidents at a number of nuclear power plants in Fukushima, highlighting the need for a study on the seismic safety of multiple NPP (Nuclear Power Plant) units. In the case of nuclear power plants built on a site that shows a similar seismic response, there is at least a correlation between the seismic damage of structures, systems, and components (SSCs) of nuclear power plants. In this study, a probabilistic seismic safety assessment was performed for the loss of essential power events of twin units. To derive an appropriate seismic damage correlation coefficient, a probabilistic seismic response analysis was performed. Using the external event mensuration system program, we analyzed the seismic fragility and seismic risk by composing a failure tree of multiple loss of essential power events. Additionally, a comparative analysis was performed considering the seismic damage correlation between SSCs as completely independent and completely dependent.

• Journal of Korean Critical Care Nursing
• /
• v.6 no.2
• /
• pp.51-64
• /
• 2013

Purpose: This study was to analyze adherence to self-care behaviors and identify factors affecting the adherence behaviors among inpatients with heart failure. Methods: A total 94 hospitalized inpatients from three hospitals participated in a survey. Data were collected using structured self-reported questionnaire from November 28, 2011 to March 31, 2013 and analyzed using frequency, t-test, ANOVA, Pearson's correlation coefficients and stepwise multiple regression. Results: The score of adherence to self-care behaviors among inpatients with heart failure was $26.02({\pm}8.84)$. Factors related to the adherence to self-care behaviors were living with spouse (t=-2.47, p=.019), functional state (t=2.18, p=.034), heart failure knowledge (r=-.49, p<.001), social support (r=-.35, p<.001), self-control (r=-.25, p=.016), and self-care confidence (r=-.24, p=.019). The factors affecting adherence to self-care behaviors were heart failure knowledge, self-care confidence, and social support. These factors explained 32% of the variance in adherence to self-care behaviors. Conclusion: The adherence to self-care behaviors with heart failure can be improved if heart failure knowledge, self-care confidence, and social support are improved. Therefore, developing a nursing intervention program for patient with heart failure that is considered these factors leads to improve quality of life and prevent readmission.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.10 no.4
• /
• pp.349-360
• /
• 2008

In this paper, the modeling procedure of random field with an elasto-plastic finite element algorithm and probability of failure on closely-spaced tunnel were investigated. Local average subdivision (LAS) method which can generate discrete random variables fast and accurately as well as change the resolution in certain region was used. And correlated value allocating and weighted average method were suggested to implement geometrical characteristics of tunnel. After the probability of failure on the test problem was thoroughly investigated using random finite element method, the results were compared with the deterministic strength reduction factor method and single random variable method. Of particular importance in this work, is the conclusion that the probability of failure determined by simplified probabilistic analysis, in which spatial variability is ignored by assuming perfect correlation, can be estimated from the safety factor determined by strength reduction factor method. Also, single random variable method can lead to unconservative estimates of the probability of failure.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.6
• /
• pp.407-418
• /
• 2003

It is necessary, in the light of the importance of long-term slope stability problem, to develop a simple method or tool which can figure out the possible failure surface resulting from weathering effect and other factors. The FBG(Fiber Bragg Crating) sensor system is used to estimate the correlations between the soil temperature and the slope behavior, and to find a failure surface in slopes effectively. This research is to seek for the correlation between the soil temperature distribution and the strain distribution of the reinforcing materials in an active zone by analyzing the data from the in-situ measurement so that the possible failure surface should be well defined based on the correlation. The zone of high temperature fluctuation can be regarded as one of the possible failure surface due to the weathering effect while the constant temperature depth of the ground, if exists, would not be relatively affected by the weathering process.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.3
• /
• pp.92-98
• /
• 2017

The rapid growth of engineering technology and the emergence of systemized and large-scale engineering systems have resulted in complexity and uncertainty throughout the lifecycle activities of engineering systems. This complex and large-scale engineering system consists of numerous components, but system failure can be caused by failure of any one of a number of components. There is a real difficulty in managing such a complex and large-scale system as a part. In order to efficiently manage the system and have high reliability, it is necessary to structure a system with a complex structure as a sub-system. Also, in the case of a system in which cause of failures exist at the same time, it is required to identify the correlation of the components lifetime and utilize it for the design policy or maintenance activities of the system. Competitive risk theory has been used as a theory based on this concept. In this study, we apply the competitive risk theory to the models with combined structure of series and parallel which is the basic structure of most complex engineering systems. We construct a competing risks model and propose a mathematical model of net lifetime and crude lifetime for each cause of failure, assuming that the components consisting a parallel system are mutually dependent. In addition, based on the constructed model, the correlation of cause of failure is mathematically analyzed and the hazard function is derived by dividing into net lifetime and crude lifetime.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.13 no.1
• /
• pp.9-17
• /
• 2001

A probability of failure of armor units on rubbJe-mound breakwater are evaluated by using the direct method for reliability analysis, which is represented as a function of safety factor that has been extensively used in practical design. The reliability function is fonnulated based on Hudson formula suggested for designing the stable size of armor units on rubble-mound breakwater. Several kinds of stability coefficient are applied separately to calculate the probability of failure with respect to the type of armor units, breaking/nonbreaking and the correlation coefficients between random variables. [n addition, the sensitivity analyses are carried out to investigate quantitatively into the effects of each random variable in the reliability function on the probability of failure.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.22 no.2
• /
• pp.171-181
• /
• 2016

Purpose: This study examined the effects of nursing professionalism, academic failure tolerance and social self-efficacy on college life satisfaction among nursing students. Methods: Data were collected between September 1 and October 16, 2015 via a self-reported questionnaire from 170 nursing students using convenient sampling methods. The survey included questions about nursing professionalism, academic failure tolerance, social self-efficacy, and college life satisfaction. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficient, and hierarchical multiple regression with IBM SPSS/WIN 20.0. Results: Establishment vision about nursing science (${\beta}=.27$, p=.006), academic failure tolerance (${\beta}=.17$, p=.031) and social self-efficacy (${\beta}=.19$, p=.012) of nursing students were identified as significant predictors of college life satisfaction, after adjusting for establishment vision about nursing science and satisfaction in nursing science. This model explained 21.0% of the college life satisfaction in nursing students (F=6.38, p<.001). Conclusion: These results suggest that academic failure tolerance and social self-efficacy were significant factors influencing the college life satisfaction of nursing students. Also, as a strategy for improving the college life satisfaction of nursing students, it is necessary to develop programs that can help to establish apparent vision and to improve satisfaction in nursing science.

• Structural Engineering and Mechanics
• /
• v.78 no.2
• /
• pp.209-218
• /
• 2021

For engineering, there are two major challenges in reliability analysis. First, to ensure the accuracy of simulation results, mechanical products are usually defined implicitly by complex numerical models that require time-consuming. Second, the mechanical products are fortunately designed with a large safety margin, which leads to a low failure probability. This paper proposes an efficient and high-precision adaptive active learning algorithm based on the Kriging surrogate model to deal with the problems with low failure probability and time-consuming numerical models. In order to solve the problem with multiple failure regions, the adaptive kernel-density estimation is introduced and improved. Meanwhile, a new criterion for selecting points based on the current Kriging model is proposed to improve the computational efficiency. The criterion for choosing the best sampling points considers not only the probability of misjudging the sign of the response value at a point by the Kriging model but also the distribution information at that point. In order to prevent the distance between the selected training points from too close, the correlation between training points is limited to avoid information redundancy and improve the computation efficiency of the algorithm. Finally, the efficiency and accuracy of the proposed method are verified compared with other algorithms through two academic examples and one engineering application.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.26 no.1
• /
• pp.52-61
• /
• 2019

Purpose: The aim of this study was to examine the mediating effect of self-efficacy in the relationship of physical and psychological symptoms to exercise adherence in patients with heart failure. Methods: The participants in this study were 186 patients with heart failure in two hospitals located in Busan. The measures included questions about general and disease characteristics, physical symptoms, psychological symptoms, self-efficacy for exercise, and exercise adherence. Data were analyzed using t-test, ANOVA, Pearson correlation coefficients, simple and multiple regression using Baron and Kenny steps for mediation. Results: There were significant differences in age, gender and comorbidity on exercise adherence. There were also significant correlations among physical and psychological symptoms, self-efficacy for exercise, and exercise adherence. Self-efficacy for exercise showed partial mediating effects in the relationship between physical symptoms and exercise adherence. Conclusion: Based on the findings of this study, the enhancement of self-efficacy for exercise may positively affect the exercise compliance of the patients with health failure, even while they are experiencing physical symptoms. Therefore, it is necessary to develop effective strategies to enhance self-efficacy for exercise.