• Journal of Korean Institute of Industrial Engineers
• /
• v.29 no.2
• /
• pp.145-149
• /
• 2003

We consider the estimation of failure rate and acceleration factor under type-I censoring without using acceleration model when testing is conducted in only one highly accelerated condition. Failure times of an item are assumed to be exponentially distributed. It is also assumed that the uncertainty about the acceleration factor, the failure time contraction ratio between accelerated condition and use condition, can be modeled by the uniform or gamma prior distribution of appropriate parameters. We respectively use Bayes and maximum likelihood approaches to estimate acceleration factor and failure rate in the use condition. An example is given to show how the method can be applied.

• Journal of Korean Society for Quality Management
• /
• v.24 no.4
• /
• pp.14-28
• /
• 1996

We consider optimal designs of partially accelerated life testing which is deviced for parallel systems with the considerably long life time. In partially step-stress life testing, test items are first run simultaneously at use condition for a specified time, and the surviving items are then run at accelerated condition until a predetermined censoring time. In partially constant-stress life testing, test items are run at either use or accelerated condition only until a specified censoring time. The optimal criterion for each test is to minimize either the generalized asymptotic variance of maximum likelihood(ML) estimators of the hazard rates at use condition and the acceleration factors or the asymptotic variance of the ML estimators of the acceleration factors.

• Journal of the Korean Professional Engineers Association
• /
• v.35 no.4
• /
• pp.19-23
• /
• 2002

Recently, deficit of water for daily We, industrial, agricultural use and Increasing water demand of river maintenance has increased gradually by the improvement of living condition of the Republic of Korea. Comprehensive measures for water deficit In the future are studied, based on the Investigated result of the actual condition of water use.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2003.11a
• /
• pp.321-324
• /
• 2003

The purpose of this paper is to analyze the actual condition, the result and the problem of the military defense CALS system and seek the way of the effective use of the military defense CALS. We perform an analytic hierarchy process to find the factors that have an influence on the effective use of CALS and evaluate the level of importance of these factors. Also we estimate the actual condition and the result by the Likert 7 scale.

• The Journal of Korean Medicine
• /
• v.40 no.1
• /
• pp.34-45
• /
• 2019

Objectives : To maintain a healthy skin condition, the role of moisture in the stratum corneum is important. We use soap in our daily life, so we wanted to observe the changes of the skin moisture using herbal CP soap. Four kinds of herbal CP soaps were prepared and their effects on skin moisture were compared. Methods: We surveyed 39 students at A University to determine their subjective skin condition, lifestyle and washing habits. Then, a facial analysis test was performed. We made herbal CP soaps using Kyungohkgo, Hwangryunhaedoktang, Seosiokyongsan and Baeksoooh and distributed them to experiment participants. Prior to the experiment, their skin condition was checked and skin condition was assessed using Facial Diagnosis System three times in total. After the experiment, the change of skin was measured and analyzed. Results: As a result of examining the skin moisture according to the using of the herbal CP soap by the participants, the skin moisture was gradually increased compared with before use. The moisture content increased after 6 weeks of use compared to before using Seosiokyongsan, Hwangryunhaedoktang, Kyungohkgo CP soap compared to before use. But there was no significant difference between 3 weeks and 6 weeks of use compared to before use. As a result of using Baeksoo-oh CP soap, the skin moisture of the experimental participants was continuously increased. Conclusion: Natural CP soaps are believed to have a beneficial effect in increasing the moisture content of facial skin.

• Journal of Korean Society for Quality Management
• /
• v.27 no.3
• /
• pp.79-93
• /
• 1999

The common accelerated life test(ALT) consists of test methods applying a constant stress, higher than the use condition stress, to items. There we, however, situations for which a progressive stress ALT, in which the stress on a test item is continuously increased with time, Is more convenient to perform testing and simpler in analyzing data than a constant stress ALT. When a product under constant stress s follows a Weibull distribution with parameters $\theta$(5) and $\beta$, maximum likelihood(ML) estimators of parameters involved in the model are obtained and their asymptotic distributions are derived under stress bounded ramp tests in which the stress is increased linearly from use condition stress to the stress upper bound. The optimum test plans are also found which minimize the asymptotic variance of the ML estimator of the log mean life at design constant stress. For selected values of the design parameters, tables useful for finding optimal test plans are given. The effect of the pre-estimates of design parameters is studied.

• Journal of Information Technology Applications and Management
• /
• v.23 no.2
• /
• pp.153-176
• /
• 2016

This study investigated factors affecting the use intention of podcast service users based on the unified theory of acceptance and use of technology (UTAUT). Performance expectancy, effort expectancy, social influence, facilitating condition, hedonic motivation, innovativeness, and media credibility were used as independent variables in the model. The survey data from the users of the podcast portal 'podbbang' were analyzed with Smart PLS 2.0 to test the structural equation model. The results revealed that the podcast service user's effort expectancy, facilitating condition, hedonic motivation, and media credibility have a significant influence on use intention. However, the relationship between the podcast service user's performance expectancy, social influence, innovativeness, and use intention were not identified as significant.

• Journal of Acupuncture Research
• /
• v.29 no.5
• /
• pp.127-137
• /
• 2012

Objectives : The purpose of this study is to review on current status of use and measurement condition of heart rate variability(HRV) by reviewing clinical studies published in journal of Korean medicine registered Korea citraion index(KCI). Methods : One hundred twenty articles were found by searching the representative Korean databases. At first analysis was performed by current status of use(journal, academic field of corresponing author, purpose of study, disease of subject, HRV measurement devices, intervention methods and tests compared to HRV). At second analysis was performed by measurement condition(uncontrolled study, relaxation before measurement, measurement position, measurement place, measurement time period and restriction of smoking, alcohol, caffeine, meal). Results : The analysis showed that department of acupuncture & moxibustion, department of oriental neuropsychiatry are major part in journal & academic field. The purpose of study were classified under studies to verify therapeutic effect on normal subject(39%), to verify therapeutic effect on the patients(8%), to investigate characteristics of the patients(34%) and to be compared with other test(19%). Disease of subject & measurement devices in article were so various. Major intervention methods were acupuncture(61.4%), mind-body intervention(19.2%). Studies that measurement condition were not controlled were relax time(24%), measurement position(19%), measurement place(26%), measurement time period(91%) and restriction of smoking, alcohol, caffeine, meal(49%). Conclusions : This study showed that current status of use of HRV is widespread in Korean medicine but more controlled measurement conditon are needed to get more reliable result from clinical studies and to improve diagnosis and treatment of Korean medicine.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.53 no.5
• /
• pp.9-16
• /
• 2011

Curve Numbers (CN) for the combination of land use and hydrologic soil group were regionalized at Imha Watershed using Long-term Hydrologic Impact Assessment (L-THIA) coupled with SCE-UA. The L-THIA was calibrated during 1991-2000 and validated during 2001-2007 using monthly observed direct runoff data. The Nash-Sutcliffe (NS) coefficients for calibration and validation were 0.91 and 0.93, respectively, and showed high model efficiency. Based on the criteria of model calibration, both calibration and validation represented 'very good' fit with observe data. The spatial distribution of direct surface runoff by L-THIA represented runoff from Thiessen pologen at Subi and Sukbo rain gage station much higher than other area due to the combination of poor hydrologic condition (hydrologic soil C and D group) and locality heavy rainfall. As a results of hydrologic condition and treatment for land use type based on calibrated CNs, forest is recommended to be hydrologically modelled dived into deciduous, coniferous, and mixed forest due to the hydrological difference. The CNs for forest and upland showed the poor hydrologic condition. The steep slope of forest and alpine agricultural field make high runoff rate which is the poor hydrologic condition because CN method can not consider field slope. L-THIA linded with SCE-UA could generated a regionalized CNs for land use type with minimized time and effort, and maximized model's accuracy.

• Journal of Korean Home Economics Education Association
• /
• v.10 no.2
• /
• pp.145-161
• /
• 1998

The purpose of this study was to survey the actual condition of the Middle School Students on a Drug. In this study, 500 middle school students in Seoul response to a questionnaire which is composed to analyse two categories, i.e. general facts, the actual condition of drug use (the frequency of drug use, the degree of perception on drugs, the people using a drug surrounding the degree of purchase on drugs). And the students are classified by satisfactory degree on their home backgrounds, satisfactory degree on their school life, and school record. The data is analysed by means of frequency, percentage, chi-square test and Pearson's correlation using the $SPSS-PC^+$ package program. The results of this study were as follow : The frequency of drug use except a alcohol and the degree of perception on a drug among female students are higher than among male. The female students are more permissive on the drug use and they are also tend to think more easily the purchase of a drug. The frequency of drug use and the degree of perception on drugs are higher in the group of the lower satisfactory degree on their home background. Especially, there are many people using drugs surrounding the students in the lower group. The frequency of drug use and the degree of perception on drugs are higher in the group that has the lower satisfactory degree on school life. The students in the group having low school record have more dangerous thought about the use of drugs than the students of high record. The degree of perception on a drug is higher in a higher group, and the students in a higher group also think more easily the purchase of drugs. The percentage of students using drugs are not high, but the high percentage of students are interested in the drugs and they have permissive attitudes on drugs. Thus, the preventive education for drug abuse must be done rapidly.