• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.9
• /
• pp.2792-2799
• /
• 1996

It was shown in the previous study that the numerically derived elastic work factor for CLS specimen was independent of fiber direction for a unidirectional case. Also, it was proposed the elastic work factor could be used to determine energy release rate from a single test record. In the present study, elastic work factor was derived from a simple beam theory to investigate its dependence on material property and geometric condition. Also, the elastic work factor of CLS specimen was applied experimentally to determine critical energy release rate in order to prove its validity determining critical energy release rate from a single specimen. For this purpose, critical energy release rate determined using the elastic work factor was compared with that determined by the compliance method. The results showed that while elastic work factor is affected by $t_2/t_1$ and $L_2/L_1$ it is independent of fiber angle for a unidirectional case. It was also found that critical energy release rates determined by both methods are comparable each other, thus elastic work factor approach can be used to determine energy release rate from a single test specimen.

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.1
• /
• pp.125-134
• /
• 2014

6 sigma is a management innovation strategy which improves most of all managerial processes including transactional and project based operations such as marketing, purchasing, accounting, and construction. Even though 6 sigma is trying to solve problems from the customer's viewpoint in the scientific manner, project leader feels some difficulties in implementation because of several reasons. Especially the difficulties are prevalent in construction site. This paper investigates the cause of the difficulties through questionnaires, analyzes the investigation results, and verifies the critical success factors of 6 sigma implementation. Factor analysis has been usually employed in reducing quantity of data and summarizing information chaos. In this study, several variables from questionnaires are grouped into just only four factors by the process of factor analysis. The critical success factors are extracted as project management system, implementation mechanism, site condition, and project ownership. Some ideas for each individual success factor are suggested, which are expected to be useful in successful implementation of 6 Sigma in construction site.

• Journal of Korean Society of Rural Planning
• /
• v.14 no.3
• /
• pp.11-17
• /
• 2008

Drawing on Herzberg's two-factor theory, this article suggests that visitors to rural tourism base their overall evaluation with an experience on their consideration of two types of aspects referred to as either 'motivators' and 'hygienes' by using the critical incident technique. 233 critical incidents described by 121 participants are categorized into three exclusive factors which are named as experiential factor, cognitive factor, and affective factor. The application of Herzberg's two-factor theory to rural tourism suggests 'satisfiers' to come from the experience-activity itself, experiential factor. While more peripheral elements constitute 'dissatisfiers', cognitive factor. The paper provides the advancement and broad application of Herzberg's theory to further understand rural tourists satisfaction.

• Journal of Korean Academy of Nursing
• /
• v.48 no.3
• /
• pp.323-334
• /
• 2018

Purpose: The purpose of this study was to develop a scale to measure person-centered critical care nursing and verify its reliability and validity. Methods: A total of 38 preliminary items on person-centered critical care nursing were selected using content validity analysis of and expert opinion on 72 candidate items derived through literature review and qualitative interviews. We conducted a questionnaire survey with 477 nurses who worked in intensive care units. The collected data were analyzed using exploratory factor analysis (EFA) and confirmative factor analysis (CFA) with SPSS and AMOS 24.0 program. Results: EFA was performed with principal axis factor analysis and Varimax rotation. The 15 items in 4 factors that accounted for 50.8% of the total variance were identified by deleting the items that were not meet the condition that the commonality should be .30 or more and the factor loading over .40. We named the factors as compassion, individuality, respect, and comfort, respectively. The correlation coefficient between this scale and the Caring Perception Scale was r=.57 (p<.001), which determined concurrent validity. The item-total correlation values ranged from .39 to .63, and the internal consistency for the scale was Cronbach's ${\alpha}=.84$. Conclusion: The reliability and validity of the 15 item person-centered critical care nursing scale were verified. It is expected that the use of this scale would expand person-centered care in critical care nursing.

• Geomechanics and Engineering
• /
• v.6 no.1
• /
• pp.1-15
• /
• 2014

In this study, artificial neural network (ANN) and multiple regression (MR) models were developed to predict the critical factor of safety ($F_s$) of the homogeneous finite slopes subjected to earthquake forces. To achieve this, the values of $F_s$ in 5184 nos. of homogeneous finite slopes having different slope, soil and earthquake parameters were calculated by using the Simplified Bishop method and the minimum (critical) $F_s$ for each of the case was determined and used in the development of the ANN and MR models. The results obtained from both the models were compared with those obtained from the calculations. It is found that the ANN model exhibits more reliable predictions than the MR model. Moreover, several performance indices such as the determination coefficient, variance account for, mean absolute error, root mean square error, and the scaled percent error were computed. Also, the receiver operating curves were drawn, and the areas under the curves (AUC) were calculated to assess the prediction capacity of the ANN and MR models developed. The performance level attained in the ANN model shows that the ANN model developed can be used for predicting the critical $F_s$ of the homogeneous finite slopes subjected to earthquake forces.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.15-16
• /
• 2011

Construction automation and robotics are being taken notice as an alternative to improve productivity and quality. Reflecting on these purpose, automation system, called RCA(Robotic-crane based Construction Automation) system, is developed and have been verified through a pilot project recently in Korea. To apply the RCA system in high-rise building effectively, each management factors of element technologies in the system is derived and assessed critical factor. The purpose of this study, management factors of element techniques, consisted of RCA system, is classified through questionnaires/interviews targeting system developers and construction managers in pilot project site, and critical factors is selected using AHP.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.21 no.3
• /
• pp.320-329
• /
• 2015

Purpose: The purpose of this study was to identify the relationship among hesitation factor of questions, critical thinking disposition, and problem solving. Methods: Data were collected from 370 students at a university in D city using a structured questionnaire from April 1 to April 15, 2015. It was analyzed with frequency analysis, descriptive statistics, t-tests, ANOVA, and correlation analysis. Results: Subjects scored an average of $2.62{\pm}.52$ for hesitation factor of questions, $3.53{\pm}0.42$ for critical thinking disposition, and $3.44{\pm}0.44$ for problem solving. There were significant differences in the three variables according to satisfaction with major, self-expression, and interpersonal relationships. In addition, hesitation factor of questions exhibited a significant difference between genders. Hesitation factor of questions had a negative relationship with critical thinking disposition (r=-.23, p<.001) and with problem solving (r=-.34, p<.001). In addition, there was a statistically significant positive correlation between critical thinking disposition and problem solving (r=.69, p<.001). Conclusion: In order to improve critical thinking disposition and problem solving, we need to generate a lot of questions to the student's inside. We also need to develop appropriate teaching methods so that this can be expressed by the actual question coming from the control hesitation factor of questions.

• Structural Engineering and Mechanics
• /
• v.13 no.3
• /
• pp.329-343
• /
• 2002

In this research, the dynamic stability of an orthotropic elastic conical shell, with elasticity moduli and density varying in the thickness direction, subject to a uniform external pressure which is a power function of time, has been studied. After giving the fundamental relations, the dynamic stability and compatibility equations of a nonhomogeneous elastic orthotropic conical shell, subject to a uniform external pressure, have been derived. Applying Galerkin's method, these equations have been transformed to a pair of time dependent differential equations with variable coefficients. These differential equations are solved using the method given by Sachenkov and Baktieva (1978). Thus, general formulas have been obtained for the dynamic and static critical external pressures and the pertinent wave numbers, critical time, critical pressure impulse and dynamic factor. Finally, carrying out some computations, the effects of the nonhomogeneity, the loading speed, the variation of the semi-vertex angle and the power of time in the external pressure expression on the critical parameters have been studied.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.10a
• /
• pp.291-295
• /
• 2003

The occurrence of ductile fracture is the working limit of many metal forming processes. It is necessary to predict the criteria and to apply the condition in a process design. Over the years. the way for clarifying conditions have been studied and presented. However such a way needs lots of experiments and analysis. In this study, in order to determine the critical damage value of a used material Cu 4N, it was performed a tensile test and FEM analysis by using DEFORM 2D. For applying the obtained critical damage value it was also performed a upsetting test by using DEFORM 2D. The way of determining a critical damage value which is presented in this study will make possible to find easily it which is one of the working limit factor. And the way of determining a critical damage value will make possible to find in multi-pass drawing process.

• Geomechanics and Engineering
• /
• v.1 no.1
• /
• pp.85-96
• /
• 2009

The radius and coordinate of sliding circle are taken as searching variables in slope stability analysis. Genetic algorithm is applied for searching for critical factor of safety. In order to search for critical factor of safety in slope stability analysis efficiently and in a robust manner, some improvements for simple genetic algorithm are proposed. Taking the advantages of efficiency of neighbor-search of the simulated annealing and the robustness of genetic algorithm, a hybrid optimization method is presented. The numerical computation shows that the procedure can determine the minimal factor of safety and be applied to slopes with any geometry, layering, pore pressure and external load distribution. The comparisons demonstrate that the genetic algorithm provides a same solution when compared with elasto-plastic finite element program.