• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.23 no.1
• /
• pp.56-61
• /
• 2015

Because of kinematic complexities, nonlinear behavior, etc, the performance of oleo-pneumatic landing gear is predicted by qualified commercial softwares. While commercial softwares predict more exactly, it takes a long time to construct or modify a model. At initial design stage, design parameters can be determined quickly and exactly enough with simple 2 degree of freedom model of mass, spring and damping. 2 degree of freedom model can be easily applied to optimization and reliability analysis which takes repetitive computation. In this paper, oleo-pneumatic landing gear is modeled as a nonlinear 2 degree of freedom model. The analysis are compared with landing gear drop test. To determine design parameter, optimization problem is solved with genetic algorithm and 2 degree of freedom model.

• The Korean Journal of Health Service Management
• /
• v.14 no.2
• /
• pp.67-77
• /
• 2020

Objectives: The Purpose of this study is to investigate the effect of self-leadership on the organizational effectiveness of a dental hygienist who has completed a bachelor's degree of dental hygiene science. Methods: A self-reported questionnaire was completed by 303 dental hygienists in the Jeonbuk area from July 1 to August 31, 2019. Data were analyzed through the chi-square test, t-test, one-way ANOVA, and multiple regression analysis using the SPSS 18.0 program. Results: Subject's age, marital status, and clinical experience had significant effects on self-leadership and organizational effectiveness. It was found that the course completion status of bachelor's degree was related to self-leadership and organizational effectiveness. Conclusions: Completing a bachelor's degree in dental hygiene science impacts self-goal setting and constructive thinking of self-leadership. This also influences job satisfaction and organizational commitment.

• Journal of Advanced Navigation Technology
• /
• v.5 no.1
• /
• pp.11-18
• /
• 2001

In this paper, we evaluated the performance of Orthogonal MC/FH-CDMA system considering the hit of frequency hopping patterns, and obtained the degree of the performance improvement by adopting TCM scheme under frequency selective Rayleigh fading channel. From the performance analysis, it is known that the error performance is improved, since delay time relative to symbol time is reduced as the number of carrier is increased. On the other hand, it is found that BER performance is improved about $5{\times}10^{-2}$ degree by adopting TCM scheme, and higher S/N is required if the QoS of voice (BER = $10^{-3}$) must be achieved.

• Journal of Korean Academy of Nursing Administration
• /
• v.22 no.3
• /
• pp.251-259
• /
• 2016

Purpose: The purpose of this study was to examine the effects of workplace spirituality and organizational citizenship behavior on nurses' performance of nursing. Methods: This study was done over a 6 month period, with 395 nurses participants from 5 different general hospitals with 400 beds in 4 regions of Korea. Data were gathered using self-reported questionnaires from July 23 to August 21, 2015. Data were analyzed using descriptive statistics, independent t-test, one way ANOVA, Pearson correlation coefficients, and multiple regression analyses with IBM SPSS 21.0 program. Results: Nursing performance showed positive correlations with workplace spirituality and organizational citizenship behavior. The significant predictors of the nursing performance by nurses were a master's degree or higher (${\beta}=.26$), civic virtue (${\beta}=.19$), courtesy (${\beta}=.12$), 40 years of age or older (${\beta}=.09$), a sense of empathy (${\beta}=.07$), and a bachelor's degree in nursing (${\beta}=.06$). These variables explained 39.2% of the variance in nursing performance by nurses. Conclusion: Based on the outcomes of this study, there is a need to develop intervention programs that can inspire nurse to show spontaneous organizational citizenship behavior, and enhance their workplace spirituality. Related variables including academic credentials should also be taken into account.

• Research in Community and Public Health Nursing
• /
• v.10 no.2
• /
• pp.307-319
• /
• 1999

The purpose of this study was to identify the major factors affecting performance in health promoting lifestyle of industrial workers. The subjects for this study 241 workers employed in S company in T city and were obtained by a convenience sample. Data were collected from March 2 to April 28. 1998. The collected data were analyzed using frequency. percent. mean. cronbach alpha. t-test. ANOVA. Person coefficients of correlation. Duncan test. stepwise multiple regression with an SPSS program. The results of this are summarized as follows. 1) The average score of performance in the health promoting lifestyle was 2.62. The variable with the highest degree of performance was harmonious relationship. whereas the one with the lowest degree was professional health maintenance. 2) Performance in the health promoting lifestyle was significantly correlated with self esteem, internal health locus of control and powerful others health locus of control. 3) Performance in the health promoting lifestyle was significantly correlated with such demographic variables as age. religion, education level. marital state. family number. types of dwelling. 4) The most important factor that affect performance in the health promoting lifestyle was powerful others health locus of control and self esteem. On the basis of this study. other factors affecting others health promoting lifestyle should be identified.

• Journal of the Korean Society of Visualization
• /
• v.14 no.1
• /
• pp.19-26
• /
• 2016

Modern people spend much time at indoor space. So, People want to make better indoor air condition. But the facade of building is made of glass to be seen urbanely, the effect of solar radiation makes indoor environment worse. This study designs an open space affected by solar radiation with 4-way cassette air-conditioner. Using numerical simulation, this paper investigates thermal comfort and ventilation performance with discharge angles $30^{\circ}$ and $45^{\circ}$. To study thermal comfort, this paper studies distribution of velocity, temperature and effective draft temperature. Also, this paper introduces concept of air age to study ventilation performance. The flow influenced by solar radiation determines thermal comfort and ventilation performance in room space. This study shows that discharge angle of 45 degree has better thermal comfort and ventilation performance than that of 30 degree.

• Korean Journal of Occupational Health Nursing
• /
• v.16 no.1
• /
• pp.5-14
• /
• 2007

Purpose: The purpose of this study was to investigate the factors influencing performance of the clinical nurses about the management of nosocomial infection. Method: The data were collected using structured questionnaire from 300 clinical nurses from April 26, 2004 to May 20, 2004. The data analyzed by the SPSS (ver10.0)program, and it included descriptive statistics, t-test, ANOVA, the Pearson correlation coefficient, stepwise multiple regression. Result: Personal hygiene management and disinfection equipment management had the higher record than other dimensions. The level of recognition for management of nosocomial infection showed positive correlation with the level of performance for management of nosocomial infection. The level of recognition for management of nosocomial infection, working period, number of hand washing, have significant effects on the degree of a performance for management of nosocomial infection. These predictive variables of the degree of a performance for management of nosocomial infection explained 17% of variance. Conclusion: It is needed to be developed for the effective management of nosocomial infection through the educational program.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.1 no.3
• /
• pp.1-11
• /
• 1993

An experimental study was carried out to evaluate the characteristics of transient performance of carburettered gasoline engine under rapid accelerating transient driving conditions. In order to evaluate the characteristics of transient performance quantitatively, the concept of dead time $t_d$ response delay time $t_r$ are introduced. Performance parameters such as air mass fiowrate Gat, engine speed N, manifold boost pressure Pb, and output torque T are measured simultaneously during the rapid opening of the throttle valve by the stepping motor. During the rapid opening of the throttle valve, air mass fiowrate Gat is increased immediately without delay time, but response of engine revolution N, and output torque T are delayed. Therefore hesitation, and stumble phenomena are occurred. Dead time $t_d$ and response delay time $t_r$ of engine revolution N, which is extremely delayed comparing to other performance parameters, are respectively 0.2-0.3sec., 3.0-4.6sec., and dead time rate $t_d/{\Delta}t$ and response delay time rate $t_r/{\Delta}t$ are linearly increased with the throttle valve opening rate ${\theta}$ during the acceleration from 12 degree to 20 degree at 1250rpm.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.11
• /
• pp.195-204
• /
• 2020

The aim of this study is to estimate the impact of ownership structure on the performance of listed firms in transition economy. Buiding upon agency theory, hypotheses on such relationship are proposed. A detailed panel data of 502 non-financial companies listed on Ho Chi Minh Stock Exchange and Hanoi Stock Exchange over the period from 2013 to 2018, and the system generalized method of moment estimation are employed to test the proposed hypotheses. To ensure the reliability of data, this study excludes companies that violate information disclosure regulations or that are subject to special supervision by the State Securities Commission of Vietnam. Some firms with inadequate information, firms that lack the financial data required for creating variable or firms that have inconsistent construction are also re-screened. We only collect the data of enterprises that have ownership structure of two or more components. Estimation results reveal that state ownership has an U-shaped relationship with the performance of Vietnamese listed firms, while foreign ownership and the degree of ownership concentration have an inverted U-shaped relationship with listed firms' performance. The article provides governance implications that Vietnamese listed firms should decrease state ownership and foreign ownership to improve firm performance in order to boost investors' confidence.

• The Korean Journal of Rehabilitation Nursing
• /
• v.5 no.2
• /
• pp.145-155
• /
• 2002

Purpose: This study tries to analyze the differences of memory performance and the metamemory of the elderly women according to degree of depression. And also it attempts to find the correlations among the sub-concepts of metamemory which have close relationships to the memory performance followed by the depression. Methods: The subjects of this study are 60 the elderly women who are older than sixty years in Busan city, Korea. We use the MIA(Dixon, et al., 1988) to measure metamemory and measure the memory performances such as the immeadiate word recall, the delayed word recall, the word recognition task, and face recognition. Results: 1. The average point of deprssed elderly womens' metamemory was significantly lower than non-depressed womens' point(t=10.86 p<.0017). Looking into subconcept of metamemory, depressed elderly womens' strategy, capacity, change, achievement point were significantly lower than non-depressed women. 2. In terms of immediate word recall and delayed word recall performances, depressed elderly women are significantly lower than non-depressed elderly women. 3. The degree of depressed elderly womens' metamemory(strategy, achievement, change, capacity) has significant correlations with immediate word recall performances. Conclusion: Metamemory has close relationship with the memory performance of elderly women. And also depressed elderly's sub-concepts of metamemory which have influences on their memory performance are different from non-depressed elderly's sub-concepts. Therefore, when we try to develop some programs to prevent memory decrease of elderly women, we should take these point into consideration.