• Journal of Digital Contents Society
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• v.16 no.1
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• pp.63-70
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• 2015

In this paper, we estimate the life cycle from acceleration life test about the hard disk of disk array of image storage of PACS. Webuil distribution was selected by the Anderson-Darling goodness-of-fit test with data of down time at $50^{\circ}C$ and $60^{\circ}C$. The equality test of shape parameter and scale parameter was conducted, so that the probability distribution estimated from data of down time at $50^{\circ}C$ and $60^{\circ}C$ was not statistically significant. The shape parameter was 1.0409, The characteristic life was 24603.5 hours at normal user condition($30^{\circ}C$) by the analysis of weibull-arrhenius modeling which included the acceleration factor of temperature, and The activation energy was 0.5011 eV through arrhenius modeling. The failure analysis of the failure samples of acceleration test and the samples of market return was conducted, so that the share percentage of failure mode was detail difference but the rank of share percentage was almost same. This study suggest the test procedure of acceleration test of hard disk drive in PACS using environment, and help the life estimation at manufacture and use.

• Journal of Ocean Engineering and Technology
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• v.12 no.1
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• pp.76-84
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• 1998

In this 1st report, the relationship between pure creep properties and initial strain was studied and also its acoustic emission test was performed during creep test at 500, 600 and $700^{\circ}C$. And the applicability of the acoustic emission technique was investigated to analyze the quantitive relationship between all the pure properties (creep strength, creep repture time or creep life, steady state creep rate, total creep rate, creep strain, total creep strain, etc.) and the initial strains as well as to analyze AE properties during the pure creep loading condition.

• The Korean Journal of Community Living Science
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• v.14 no.1
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• pp.37-53
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• 2003

The purpose of this study was to empirically verify influence of objective variables and subjective variables of life management strategy of unmarried man and women and provide a basis for the development of time management. The subject of this study were 355 unmarried men and women and interviewed with a questionnaire. The data were analyzed by SPSS program for the frequency, mean, standard deviation, t-test and regression analysis. The major results of this study were as follows: 1. The score of time management strategy of unmarried man and women was the highest. The score of leisure management strategy of unmarried man and women was the lowest. 2. Variables that affect overall life management strategy were academic career, degree of information using, fate control orientation and perception level of living relative to others. 3. The relative contribution of subjective variables on life management strategy were higher than objective variables.

• Journal of Applied Reliability
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• v.14 no.1
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• pp.45-51
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• 2014

Thermal shock tests at two stress levels were performed to see the life (cycles) of LPF ASSY (low pass filter assembly) at normal stress level. In this case Coffin-Manson relationship is generally used to describe the relationship between the temperature difference and the life, together with the Weibull distribution describing the life at each stress level. So for given data Coffin-Manson is fitted to predict the life at normal stress level. However, different types of models are appropriate for this type of test. Hence, a more appropriate model such as General log-linear model which can also incorporate the duration at the highest and lowest temperatures and acceleration time will be introduced.

• Journal of the Korean Data and Information Science Society
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• v.14 no.4
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• pp.751-758
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• 2003

We consider a life testing experiment in which several two-component shared parallel systems are put on test, and the test is terminated at a predesigned experiment time. The bivariate data obtained from such a system-level life testing can be classified into three cases: 1) the case of failed two components with known failures times, 2) the case of censored two components, and 3) the case of one censored component and the other failed component of which the failure time might be known or unknown. In this thesis, the likelihood estimators for Freund's bivariate exponential life distribution under above censoring scheme are obtained. Results of comparative studies based on Monte Carlo simulation are presented.

• Korean Journal of Human Ecology
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• v.22 no.1
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• pp.29-41
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• 2013

The aim of the current study is to examine the effects of mothers' home management ability on school-aged children's time and life management skills through the mediation effect of children's self-regulation. Study subjects were 317 5- and 6-grade children at elementary schools located in Seoul and Gyeonggi area and their 317 mothers. The findings were as follows. First, in the SEM model of predicting children's time management skill, greater mothers' home management ability significantly predicted better time management skills among their children. Second, mothers' home management ability also indirectly affected children's time management skill through its significant effects on children's self-regulation. The test yielded a significantly mediation effect of self-regulation. Children's self-regualtion was strongly related to time management skills. Third, in the SEM model predicting children's life management skills, maternal ability of home management again directly predicted greater life management skills of their children. However, mediation of self-regulation was not statistically significant. The findings suggested the important role of mothers' home management ability in instilling and modeling self-regulation and self-management skills of school-aged children.

• Journal of Families and Better Life
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• v.7 no.2
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• pp.145-161
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• 1989

The objectives of this study are ; 1) To analyze the time use and the invironments of rural housewives household labor according to the characteristics of agriculture. 2) To investigate the factors influencing household labor time. In this study, the rural areas are divided into two groups according to characteristics of agriculture. One is traditional agricultural area-Seokchon Dong in Youngcheon Kun, and the other is commercial agricultural area-Dongpo 1 Dong in Sungju Kun. Two areas are located in Kyungpook Province. 145 housewives dwelling in above two villiages were interviewed. The statistics used for data analysis were frequency, percentile, T-test, x2-test, and multiple regression analysis. Results are as follows; 1) household labor time had not significant differences Hetween Youngcheon and Sungju. But agricultural labor time was longer in Sungju than in Youngcheon. 2) household labor environments in Sungju were better than those in Youngcheon. 3) household labor time was influenced by agricultural labor time and socio-cultural time.

• Journal of Korean Home Economics Education Association
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• v.15 no.1
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• pp.1-14
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• 2003

This study was designed to contribute for improvements of middle school students' quality of life and to Present materials necessary for applying leisure activity Programs for them through an analysis of the patterns of the leisure activities and life satisfaction .For the statistical analysis. Cronbach α. t-test. ANOVA. Duncan's multiple range test were calculated. The Participants were 515 second glade students of middle school in Kangwon Province . The findings can be summarized as follows. 1) The average point of patterns of the subjects participating in leisure activities was 2.38. and activities. which are associated with computers. accounted for 3.35. the highest mark among the various patterns. 2) The patterns of the subjects' leisure activities varies significantly with sociodemographical variables such as sex. location. level of living. pocket money. and leisure expenditure Such factors as leisure time in weekends and the degree of interest in leisure made a significant difference in the patterns of leisure activities .3) The average Point of subjects life satisfaction was 3.49. and their family life satisfaction reached to 3.81 the highest mark. And the Patterns of leasure activity had a Positive relationship with the subjects' life satisfaction. consisting relatively low correlation. However, the more the subjects take Part in leasure. the more they were satisfied with life.

• Journal of the Korean Society of Safety
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• v.15 no.1
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• pp.28-35
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• 2000

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. So determination of the integrity of the metallic structure is required either to en4sure that failure will not occur during the service life of the components or to evaluate the lifetime extension of the structure. An automated ball indentation(ABI) method was developed as a non-destructive technique for evaluating the integrity of such metallic components. In this paper, we would like to present the aging evaluation technique by the ABI method. The five classes of the thermally aged CF8M specimens were prepared using an artificially accelerated aging method. After holding 100, 300, 900, 1800 and 3600 hours at 43$0^{\circ}C$, the specimens were cooled down using water to room temperature respectively. The tensile test, hardness test, charpy impact test, ABI test were performed. The results of the fracture test were compared with those of ABI test and the new evaluation technique of the integrity of metallic structures was developed.

• Advances in Traditional Medicine
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• v.6 no.1
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• pp.21-26
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• 2006

The ethanolic extract of Fleurya interrupta Gaud, (Urticaceae) was tested for its possible neuropharmacological effects on experimental animals, For the primary neuropharmacological screening of this plant, the ethanolic extract of its aerial parts was subjected to preliminary evaluation for acute toxicity, antinociceptive activity and central nervous system (CNS) activities. At the doses of 125 and 250 mg/kg, the extract significantly (P < 0.01 and P < 0. 001) and dose-dependently increased the frequency of acetic acid induced writhing in mice. In the pentobarbitone induced sleeping time test, the extract at the above dose levels, significantly and dose-dependently decreased the pentobarbitone induced sleeping time (P < 0.001) and increased the time for onset of sleep (P < 0.001) in mice. In the open field and hole cross tests, test animals showed an increase in their movement in the both tests from the 2nd observation period (30 min) and persisted throughout the entire experimental period (240 min). These results of the extract may attribute a stimulating action on the CNS. On the basis of these findings, it can be assumed that the extract exerts its stimulating effect on the CNS in mice by interfering with the cortical function or increasing the effect of some CNS stimulating neurotransmitters.