• The Journal of Korean Academic Society of Nursing Education
• /
• v.17 no.1
• /
• pp.120-128
• /
• 2011

Purpose: The purpose of this study was to test the validity and reliability of a life respect instrument for elementary school students. Method: The study was conducted as follows: identification of the tentative content domains, items generation, test of content validity, and data collecting with a preliminary questionnaire. Descriptive statistics, factor analysis, Cronbach's alpha, Guttman split-half, and Pearson correlation coefficients were used to analyze the data. Results: Two factors were extracted through factor analysis: 'Value about life respect', and 'Attitude about life respect.' These factors explained 58.82% of all factors. A total of 16 items belonging to 2 domains were generated. Cronbach's alpha and Guttman split-half coefficient were .82, and .84 respectively. Conclusion: The life respect instrument modified in this study will be useful for evaluating the effect of life respect education for elementary school students.

• The Korean Journal of Applied Statistics
• /
• v.5 no.2
• /
• pp.193-209
• /
• 1992

We consider a Step Life Testing which is deviced for a two-component serial system with the considerably long life time. In the modelling stage we discuss the bivariate exponential distribution suggested by Block and Basu as the bivariate survival function for the two-component system, and develope the cumulative exposure model introduced by Nelson so that it can be used under the bivariate function. We consider inference on the component life time when the components are at work in the system by combining the information from system life test and that from the component tests carried out separately under the controlled environment. In data analysis, maximum likelihood estimators are discussed with the initial value obtained by an weighted least square method. Finally we discuss the optimal time for changing the stress in the simple step stress life testing.

• Journal of muscle and joint health
• /
• v.13 no.1
• /
• pp.20-30
• /
• 2006

Purpose: To determine the effect of Tai Chi exercise program on fatigue, stress, and quality of life in middle aged women. Method: The study was designed as a nonequivalent control group pretest-posttest quasi-experimental study. Thirty subjects were assigned for experimental group and thirty four subjects were assigned for control group. The subjects in the experimental group were participated in Tai Chi exercise program for 60 minutes per session 3 times a week for 8weeks. Tai Chi exercise program consists of 10 minutes warm-up, 45 minutes main, and 5 minutes cooling down exercises. In order to evaluate the effect of Tai Chi exercise program, fatigue, stress, and qualify of life were assessed by measuring the condition of the participants in respect of fatigue, stress, and qualify of life with questionnaire. The data were analyzed by using $x^2-test$, Fisher's exact test, t-test by a SAS-pc+ 8.12 program. Result: After 8 weeks Tai Chi exercise program, there were significant improvement in fatigue, stress, and quality of life in middle aged women. Conclusion: Tai Chi exercise program can be an effective nursing intervention to improve fatigue, stress, and quality of life in middle aged women.

• Journal of Applied Reliability
• /
• v.12 no.2
• /
• pp.67-78
• /
• 2012

An electric double-layer capacitor(EDLC) is an electrochemical capacitor with relatively high energy density, typically hundreds of times greater than conventional electrolytic capacitors. EDLCs are widely used for energy storage rather than as general-purpose circuit components. They have a variety of commercial applications, notably in energy smoothing and momentary-load devices, and energy-storage and kinetic energy recovery system devices used in vehicles, etc. This paper presents an accelerated degradation test of an EDLC with rated voltage 2.7V, capacitance 100F, and usage temperature $-40^{\circ}C{\sim}65^{\circ}C$. The EDLCs are tested at $50^{\circ}C$, $60^{\circ}C$, and $70^{\circ}C$, respectively for 1,750hours, and their capacitances are measured at predetermined times by constant current discharge method. The failure times are predicted from their capacitance deterioration patterns, where the failure is defined as 30% capacitance decrease from the initial one. It is assumed that the lifetime distribution of EDLC follows Weibull and Arrhenius life-stress relationship holds. The life-stress relationship, acceleration factor, and $B_{10}$ life at design condition are estimated by analyzing the accelerated life test data.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.03a
• /
• pp.269-273
• /
• 1998

The failure of material structures or mechanical system is considered as a direct or indirect result of fatigue. In the design of mechanical structure for estimating of reliability, the prediction of failure life is the most important failure mode to be considered. However, because of a complicated behavior of fatigue in mechanical structure, the analysis of fatigue is in need of much researches on life prediction. This document presents a prediction of fatigue life of the SAPH45 steel, which is extensively for vehicle frame. The method using lethargy coefficient and stress distribution factor at pediction of fatigue life based on the consideration of the failure characteristics from the tensile test should be provided in this study.

• Journal of Applied Reliability
• /
• v.13 no.1
• /
• pp.65-76
• /
• 2013

In order to assess the reliability of engine mount for a vehicles, life test model and procedure are developed. By using this method, failure mechanism and life distribution are analyzed. The main results are as follows; i) the main failure mechanism is degradation failure of engine mount rubber by fatigue failure at dynamic load. ii) temperature is a second factor to affect a failure. iii) the life distribution of engine mount module is fitted well to Weibull life distribution and the shape parameter is 18.4 and the accelerated life model of that is fitted well to Arrhenius model.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.2
• /
• pp.28-35
• /
• 2019

Since guided missiles with the characteristics of the one-shot system remain stored throughout their entire life cycle, it is important to maintain their storage reliability until the launch. As part of maintaining storage reliability, period of preventive test is set up to perform preventive periodic test, in this case failure detection rate has a great effect on setting up period of preventive test to maintain storage reliability. The proposed method utilizes failure rate predicted by the software on the basis of MIL-HDBK-217F and failure mode analyzed through FMEA (Failure Mode and Effect Analysis) using data generated from the actual field. The failure detection rate of using the proposed method is applied to set periodic test of the actual guided missile. The proposed method in this paper has advantages in accuracy and objectivity because it utilizes a large amount of data generated in the actual field.

• Journal of Korean Academy of Nursing
• /
• v.35 no.1
• /
• pp.186-194
• /
• 2005

Purpose: The purpose of this study was to investigate the effect of aromatherapy on pain, depression, and feelings of satisfaction in life of arthritis patients. Method: This study used a quasi-experimental design with a non-equivalent control group, pre-and post-test. The sample consisted of 40 patients, enrolled in the Rheumatics Center, Kangnam St. Mary's Hospital, South Korea. The essential oils used were lavender, marjoram, eucalyptus, rosemary, and peppermint blended in proportions of 2:1:2:1:1. They were mixed with a carrier oil composed of almond (45%), apricot(45%), and jojoba oil(10%) and they were diluted to 1.5% after blending. The data were analyzed using an 2-test, Fisher's exact test, t-test and paired t-test. Result: Aromatherapy significantly decreased both the pain score and the depression score of the experimental group compared with the control group. However, aromatherapy didn't increase the feeling of satisfaction in life of the experimental group compared with the control group. Conclusion: The result of this study clearly shows that aromatherapy has major effects on decreasing pain and depression levels. Based on our experiment's findings, we suggest that aromatherapy can be a useful nursing intervention for arthritis patients.

• Journal of Applied Reliability
• /
• v.11 no.3
• /
• pp.235-244
• /
• 2011

Hydraulic hose assemblies deliver a fluid power in various oil pressure equipment such as construction machinery, automobile, aircraft, industrial machinery, machine tools and machinery for ships. Also, they are widely used as pipes in oil pressure circuit. When we estimate their lifetime, it is essential to conduct an accelerated life test by choosing the factor that suits the usage condition of the test object since traditional test method for estimating lifetime under the influence of various external factors incurs hardship in terms of time and expenses. The objective of this study is to propose an acceleration model that takes both temperature and pressure without flexing condition into consideration. The lifetime is estimated by applying the proposed temperature-nonthermal acceleration model to the test data. And we compare the proposed temperature-nonthermal acceleration model and the accelerated life equation suggested by John(1994).

• Journal of Korean Society for Quality Management
• /
• v.43 no.3
• /
• pp.409-420
• /
• 2015

Purpose: This study is to estimate the life of elevator wire rope by using the accelerated degradation test with two accelerating variables of applied load and corrosion. Methods: Linear regression method is used to find the pseudo life of elevator wire rope at each combination of accelerating variables and the median life of elevator wire rope at use condition is estimated under the assumption that the life of elevator wire rope follows lognormal distribution. Results: The particular case study demonstrated that the results of the elevator wire life estimation by using the proposed method can provide the better solutions than existing methods. Conclusion: It can be economical to use accelerated degradation model for estimating the life of elevator wire rope.