• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.3
• /
• pp.213-223
• /
• 2015

The helicopter initial design model was established by using the latest weight estimation equations based on the Tishchenko's methodology through the study existing initial design tools. The sequential decomposition method is used to reduce analysis time in the sizing. Empirical parameters of the weight estimation equation were also extracted from numerical and regression analysis for a helicopter database. Design input and output values were compared with the RISPECT design tool. Finally, comparison of the re-design resulting for several existing helicopters was presented and showed the good agreement within less than 5% in the weight estimation and main rotor sizing. Established initial design model was proved to be effectively used as initial design tool.

• Journal of The Korean Association For Science Education
• /
• v.17 no.4
• /
• pp.525-540
• /
• 1997

The present study tested the hypothesis that maturation of the prefrontal lobes is a crucial factor determining the performance of scientific reasoning tasks, Functions of the prefrontal lobes, such as activating relevant information, sequential planning and monitoring, and inhibiting irrelevant information, are related thinking patterns with scientific reasoning. Therefore, we inferred the idea that the prefrontal lobes play an important role in scientific reasoning. To test the hypothesis. the present study investigated a prefrontal lobe patient's task solving procedures in scientific reasoning tasks and the correlation and regression analysis between a test of prefrontal lobe function and two scientific reasoning tasks, The perseverative errors in the Wisconsin Card Sorting Test(WCST) was used as a measure of the prefrontal lobe function, The Melinark Type Task and the Classroom Test of Scientific Reasoning were used as measures of scientific reasoning abilities. Ages and Group Embedded Figure Test were also used as measures of two alternative hypotheses, general maturation and field independency respectively. The prefrontal lobe patient showed a crucial deficiency in solving scientific reasoning tasks. In the tasks, the patient could not used the reasoning of If... and... then... therefore pattern. In correlation study, the perseveration errors of the WCST showed a significantly negative correlation with two scientific reasoning tasks. Multiple regression study also showed that the perseveration errors measured as a function of the prefrontal lobes have more contribution to scientific reasoning ability than contributions of alternative hypotheses. Therefore, the present study supported the hypothesis that prefrontal lobes play a crucial role in scientific reasoning ability, What function of the prefrontal lobes do play crucial role in scientific reasoning? The present study provided an explanation for the question, which inhibiting ability of the prefrontal lobes is responsible for the scientific reasoning ability, in a part at least. That is, perseverative tendency in task-solving procedures causes a deficiency of an ability to inhibit the wrong information to solve a task. The present study provided a possibility of neuropsychological approach in science education research. The present study also showed an importance of the prefrontal lobe development in the performance of scientific reasoning task.

• Tuberculosis and Respiratory Diseases
• /
• v.67 no.5
• /
• pp.402-408
• /
• 2009

Background: Pre-B-cell colony enhancing factor (PBEF) has been suggested as a novel biomarker in sepsis and acute lung injury. We measured the PBEF in bronchoalveolar lavage (BAL) fluid of acute critically ill patients with lung infiltrates in order to evaluate the clinical utility of measuring PBEF in BAL fluid. Methods: BAL fluid was collected by bronchoscope from 185 adult patients with lung infiltrates. An enzyme-linked immunosorbent assay was then performed on the collected fluids to measure the PBEF. Results: Mean patient age was 59.9 ${\pm}$14.5 years and 63.8% of patients were males. The mean concentration of PBEF in BAL fluid was 17.5 ${\pm}$88.3 ng/mL, and patients with more than 9 ng/mL of PBEF concentration (n=26, 14.1%) had higher Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores on the BAL exam day. However, there were no significant differences in clinical characteristics between survivors and non-survivors. In patients with leukocytosis (n=93) seen on the BAL exam day, the linear regression analysis revealed a significant, positive relationship between PBEF and APACHE II ($r^2$=0.06), SOFA score ($r^2$=0.08), Clinical Pulmonary Infection Score ($r^2$=0.05), and plateau pressure in patients on ventilators ($r^2$=0.07) (p<0.05, respectively). In addition, multivariate regression analysis with PBEF as a dependent variable showed that the plateau pressure ($r^2$=0.177, p<0.05) was correlated positively with PBEF. Conclusion: The PBEF level in the BAL fluid may be a useful, new biomarker for predicting the severity of illness and ventilator-induced lung injury in critically ill patients with lung infiltates and leukocytosis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.6
• /
• pp.2917-2921
• /
• 2016

Background: To explore factors that influence quality of life (QOL) in patients receiving breast conserving therapy (BCT). Materials and Methods: In this sequential mixed methods study, 118 women from Songklanagarind Hospital were included. We used participants' characteristics, Body Image Scale (BIS), and Functional Assessment of Cancer Therapy with the Breast Cancer Subscale (FACT-B) for analysis. The BIS transformed into presence of body image disturbance (BID). Factors that influenced QOL were determined by stepwise multiple linear regression. Forty-one participants were selected for qualitative analysis. Our female researcher performed the semi-structured interviews with questions based on the symbolic interaction theory. Final codes were analysed using thematic analysis along with investigator triangulation methods. Results: Ninety percent had early stage breast cancer with post-completed BCT, for an average of 2.7 years. The median BIS score and FACT-B score were 2 (IQR=10) and 130 (IQR=39). In the regression analysis, an age of more than 50 years and BID were significant factors. As for the value of conserved breasts, two themes emerged: a conserved breast is an essential part of a participant's life and also the representation of her womanhood; the importance of a breast is related to age. Conclusions: Body image influenced QOL in post BCT participants. The conserved breasts also lead to positive and better impact on their body image as an essential part of their life.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.12
• /
• pp.1960-1965
• /
• 2001

In the practical design, it is important to extract the design space information of a complex system in order to optimize the design because the design contains huge amount of design conflicts in general. In this research FEA (finite element analysis) has been successfully implemented and integrated with a statistical approach such as DOE (design of experiments) based RSM (response surface model) to optimize the thermal deformation of an automotive disk brake. The DOE is used for exploring the engineer's design space and for building the RSM in order to facilitate the effective solution of multi-objective optimization problems. The RSM is utilized as an efficient means to rapidly model the trade-off among many conflicting goals existed in the FEA applications. To reduce the computational burden associated with the FEA, the second-order regression models are generated to derive the objective functions and constraints. In this approach, the multiple objective functions and constraints represented by RSM are solved using the sequential quadratic programming to archive the optimal design of disk brake.

• Journal of Korean Academy of Nursing
• /
• v.42 no.7
• /
• pp.1019-1026
• /
• 2012

Purpose: To examine geographical imbalances by analyzing new graduate nurses' migration patterns among regions where they grew up, attended nursing school, and had their first employment and to identify factors related to working in non-metropolitan areas. Methods: The sample consisted of 507 new graduates working in hospitals as full-time registered nurses in South Korea. Migration patterns were categorized into 5 patterns based on sequential transitions of "geographic origin-nursing school-hospital." Multiple logistic regression analysis was conducted to identify factors associated with working in non-metropolitan hospitals. Results: Nurses who grew up, graduated, and worked in the same region accounted for the greatest proportion (54%). Sixty-five percent had their first employment in the region where they graduated. Nurses tended to move from poor to rich regions and from non-metropolitan to metropolitan areas. Working in non-metropolitan hospitals was related to older age, the father having completed less than 4 years of college education, non-metropolitan origin, non-capital city school graduation, and a diploma (vs. baccalaureate) degree. Conclusion: Admitting students with rural backgrounds, increasing rural nursing school admission capacities, and providing service-requiring scholarships, particularly for students from low-income families, are recommended to address geographical imbalances.

• Journal of Mechanical Science and Technology
• /
• v.15 no.7
• /
• pp.876-888
• /
• 2001

For a large scaled optimization based on response surface methods, an efficient quadratic approximation method is presented in the context of the trust region model management strategy. If the number of design variables is η, the proposed method requires only 2η+1 design points for one approximation, which are a center point and tow additional axial points within a systematically adjusted trust region. These design points are used to uniquely determine the main effect terms such as the linear and quadratic regression coefficients. A quasi-Newton formula then uses these linear and quadratic coefficients to progressively update the two-factor interaction effect terms as the sequential approximate optimization progresses. In order to show the numerical performance of the proposed method, a typical unconstrained optimization problem and two dynamic response optimization problems with multiple objective are solved. Finally, their optimization results compared with those of the central composite designs (CCD) or the over-determined D-optimality criterion show that the proposed method gives more efficient results than others.

• Korean Journal of Adult Nursing
• /
• v.26 no.1
• /
• pp.46-57
• /
• 2014

Purpose: This study was to investigate the influence of male nurses' gender role conflict and job satisfaction on their organizational commitment. Methods: Data were collected through a mixed method design using structured questionnaires (N=162) and a sequential qualitative interviews (N=8) from 2nd October, 2012 to 7th February, 2013. Data analysis included t-test, ANOVA, regression with SPSS/WIN 19.0 program and a qualitative thematic analysis. Results: Factors affecting participants' organizational commitment were job satisfaction and marital status which accounted for 36.2% of the total variance. In particular, low job satisfaction was not correlated with low organizational commitment despite lower job satisfaction. Three main themes connoting meanings of ambivalence were extracted from the data: desiring for the better future in spite of the current difficulty, strengthening their masculinity in tandem with complementing femininity in the midst of gender role conflict, leading their organization at times, and enduring hard work with responsibility for raising their family as a head of household. Conclusion: The findings indicate that male nurses' adjustment to the organization is controlled by ambivalence. It is essential to understand sociocultural contexts of male nurses as a minority in nursing fields for further research.

• Journal of the Ergonomics Society of Korea
• /
• v.26 no.3
• /
• pp.101-109
• /
• 2007

This research is for developing a usability evaluation model based on customer sensation using Quality Function Deployment, which evaluates the relationship between consumer sensation and usability among the physical design factors of dishwashers. Four aspects of the evaluation model; overall sensation factors, detail sensation factors, usability evaluation factors and physical design factors of products were analyzed in three sequential processes of QFD. The sensation evaluation factors and the usability evaluation factors were created from regression analysis of the results of the sensation and usability test. Moreover, thirty-one physical design factors selected through group discussion of ergonomist and manufacturers. Among them, 19 physical design factors according to priority were applied to evaluation model using QFD. With the evaluation model using four aspects, physical design factors influencing user sensation were generated. These factors were 'alarm sound', 'dishwasher size', 'button size' and 'display size'. Consequently, the degree of influences was tested. Design guidelines for dishwashers were derived from finally generated physical design factors.

• Journal of the Korean Data and Information Science Society
• /
• v.24 no.1
• /
• pp.33-39
• /
• 2013

In the transformation of response variable in partial linear models outliers can cause a bad effect on estimating the transformation parameter, just as in the linear models. To solve this problem the processes of estimating transformation parameter and detecting outliers are needed, but have difficulties to be performed due to the arbitrariness of the nonparametric function included in the partial linear model. In this study, through the estimation of nonparametric function and outlier detection methods such as a sequential test and a maximum trimmed likelihood estimation, processes for transforming response variable robust to outliers in partial linear models are suggested. The proposed methods are verified and compared their effectiveness by simulation study and examples.