• Communications for Statistical Applications and Methods
• /
• v.6 no.3
• /
• pp.801-812
• /
• 1999

Change-point hazard rate models arise for example in applying "burn-in" techniques to screen defective items and in studing times until undesirable side effects occur in clinical trials. Sometimes in screening defectives it might be sensible to model two stages of burn-in. In a clinical trial there might be an initial hazard rate for a side effect which after a period of time changes to an intermediate hazard rate before settling into a long term hazard rate. In this paper we consider the multiple change points hazard rate model. The classical approach's asymptotics can be poor for the small to all moderate sample sizes often encountered in practice. We propose a Bayesian approach avoiding asymptotics to provide more reliable inference conditional only upon the data actually observed. The Bayesian models can be fitted using simulation methods. Model comparison is made using recently developed Bayesian model selection criteria. The above methodology is applied to a generated data and to a generated data and the Lawless(1982) failure times of electrical insulation.

• The Korean Journal of Applied Statistics
• /
• v.26 no.1
• /
• pp.1-14
• /
• 2013

ARIMA and ARIMA+IGARCH models are fitted and compared for daily Korean won/US dollar exchange rate data over 17 years. A linear structural change model and an autoregressive structural change model are fitted for multiple change-point estimation since there seems to be structural change with this data.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.12
• /
• pp.2505-2510
• /
• 2009

Semiconductor processes need measurement to confirm where there are problems in quality after progresses manufacturing process. This paper suggests equipment and automatic measure sampling method that control monitoring ratio according to change point occurrence availability of process that is not measure method by the existent simple ratio rate. This paper defines measure section as ailment section, metastable section and stability section by change point standard and create statistical model of each section and developed suitable measure rate model by section. As a result, we have accomplished maximum throughput and minimum sampling number that needs to maintain constant level of quality. Proposed method minimizes load of measure process by brings production quality sophistication and decrease of process badness and lowers measure rate in stable section making perception about problem occurrence quick heightening measure rate at change point occurrence.

• Human Ecology Research
• /
• v.55 no.3
• /
• pp.263-274
• /
• 2017

The purposes of this study were to verify the longitudinal mediating effects of work-family balance on the relationship of role recognition in the family, marital intimacy and job satisfaction of married women, and to introduce longitudinal mediating effects by using latent growth curve modeling and autoregressive cross-lagged modeling. The subjects were married women from the third year data of the Korean Longitudinal Survey of Women and Family. Structural equational models were conducted with Amos ver. 21.0. The major findings are as follows. First, the result of the longitudinal mediating effects of latent growth modeling is the rate of change of work-family balance mediated between the rate of change of role recognition in the family and the rate of change of job satisfaction, and the rate of change of work-family balance mediated between the rate of change of marital intimacy and the rate of change of job satisfaction. Second, when using the autoregressive cross-lagged modeling, the more role recognition and marital intimacy of third year were the more work-family balance of fourth year, job satisfaction of fifth year. In both models, work-family balance mediated between role recognition in the family, marital intimacy and job satisfaction. Therefore, through this study, mediating effects of work-family balance can be found that there was a longitudinal effects.

• Journal of Fashion Business
• /
• v.23 no.1
• /
• pp.116-126
• /
• 2019

The purpose of this study is to objectify the shape of curvature and average change rate of angular and arched eyebrow makeup. The data for the analysis were the final 336 pieces for the cosmetology students in the whole country. SPSS 20.0 program was used for the collected data, frequency analysis, factor analysis, reliability analysis, and crossover analysis were performed. First, the frequency of the average change rate of eyebrow makeup (angular and arcuate) was analyzed. As a result, the eyebrows suitable for the angled type showed the highest level of 'A-2' and the arched eyebrows had the highest level of 'B-2'. Second, to analyze the important factors of eyebrow makeup, frequency of eyebrows was the most important, followed by the inclination of eyebrows and eyebrow tail. Third, factor analysis and reliability analysis were conducted to examine each dimension of eyebrow makeup perception, and it was derived from three factors including acceptability, aggressiveness, and playability. Fourth, in order to analyze the difference of important factors in the form of the standard eyebrow makeup, the cross - analysis was performed with chi - square test, and it was confirmed that the angular eyebrow makeup showed the most objectivity when the average change rate was 0.29 and the curvature was 0.67. Fifth, arcuate eyebrow makeup showed the most objectivity when the average change rate was 0.57 and curvature was 0.56. The results of this analysis can be used as objective data of aesthetic criteria when designing the eyebrow shape.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.3
• /
• pp.1345-1362
• /
• 2019

Most active queue management algorithms manage network congestion based on the size of the queue but ignore the network environment which makes queue size change. It seriously affects the response speed of the algorithm. In this paper, a new AQM algorithm named CT-AQM (Change Trend-Adaptive Queue Management) is proposed. CT-AQM predicts the change trend of queue size in the soon future based on the change rate of queue size and the network environment, and optimizes its dropping function. Simulation results indicate that CT-AQM scheme has a significant improvement in loss-rate and throughput.

• Physical Therapy Korea
• /
• v.12 no.2
• /
• pp.90-97
• /
• 2005

By measuring changes in blood lactate and plasma enzyme (CPK, GOT, GPT) with electrical stimulation applied at two duty cycles, this study is intended to look into which type of duty cycle may have more effects on blood lactate and plasma enzyme constituents through animal experiment so as to determine any duty cycle appropriate for electrical treatment. In this study, electrical stimulation was applied to total 20 Korean house rabbits (weight: 3~3.5 kg) by means of an electrical therapeutic apparatus called TS6000 (made in Netherlands) at duty cycle of 50% and 20% respectively for 30 minutes. Here, 5 cc of blood was collected from their carotid artery before stimulation and in 30 minutes after stimulation respectively to carry out biochemical experiment and analysis. As determined through the above experiment, blood lactate rate was increased to 333.07% at 50% duty cycle after experiment and 185.71% at 20% duty cycle after experiment respectively. In both cases, blood lactate rate was significantly increased to higher level after electrical stimulation than before. Moreover, the rate of change in the average of blood lactate rate at both duty cycles also showed significant differences. CPK rate was boosted to 301.82% at 50% duty cycle after experiment and 321.35% at 20% duty cycle after experiment respectively. In both cases, CPK rate was remarkably boosted to higher level after stimulation than before (p<.05). However, there was not any significant difference in the rate of change in average CPK at both duty cycles (p<.05). GOT rate was significantly boosted up to 38.97% at 50% duty cycle after experiment (p<.05), while it was slightly increased to 1.68% at 20% duty cycle after experiment without any significant difference. Rather, GPT rate dropped slightly at both duty cycles after experiment, but there was not any significant difference. Although blood lactate and GOT were relatively less generated at 20% duty cycle after electrical stimulation than at 50% duty cycle, the change of duty cycle didn't have any significant influence on CPK rate. In this regard, this study failed to come any consistent conclusion about the association between change of duty cycle and muscle fatigue. Therefore, it is advisable that follow-up studies seek various ways to a little more effectively apply electrical stimulation to laboratory animals by avoiding their muscle fatigue. GOT rate was significantly boosted up to 38.97% at 50% duty cycle after experiment (p<.05), while it was slightly increased to 1.68% at 20% duty cycle after experiment without any significant difference. Rather, GPT rate dropped slightly at both duty cycles after experiment, but there was not any significant difference. Although blood lactate and GOT were relatively less generated at 20% duty cycle after electrical stimulation than at 50% duty cycle, the change of duty cycle didn't have any significant influence on CPK rate. In this regard, this study failed to come any consistent conclusion about the association between change of duty cycle and muscle fatigue. Therefore, it is advisable that follow-up studies seek various ways to a little more effectively apply electrical stimulation to laboratory animals by avoiding their muscle fatigue.

• Proceedings of the IEEK Conference
• /
• 2000.06c
• /
• pp.109-112
• /
• 2000

The EPRCA(Enhanced Proportional Rate Control Algorithm) is one of the explicit rate control algorithm recommended by the ATM forum. EPRCA algorithm is using only two threshold to buffer change is not considered for calculating ER value. In this paper to cover the shortage, two more variables are added for considering increase of buffer quantity. So calculating proper ER would avoid before getting into the congestion situation. To analysis the affect, EPRCA and proposed algorithm are compared through simulation by analysis of change of buffer length and ACR change

• The Journal of the Acoustical Society of Korea
• /
• v.22 no.1
• /
• pp.14-22
• /
• 2003

In this study, we examined the acoustic characteristics of Korean vowels through a production test under three conditions of speaking rates (slow, normal, fast). The effects of a change in speaking .ate on vowel duration were found to be very strong. The faster speaking rate was, the shorter the total duration of vowels was. But the duration ratio of two components of diphthong was not changed significantly according to changes in speaking rate. But unlike the temporal aspects, the formant value of vowels at their steady-state and change ratio of formant of semivowels were not affected strongly by the change in speaking rate.

• The Journal of Korean Physical Therapy
• /
• v.14 no.3
• /
• pp.174-202
• /
• 2002

Twenty five patients, 14 males and 11 females with an average age of 75years with chronic Low Back Pain were tested before, during, and after 10minutes transcutaneous electrical nerve stimulation. It is important to consider the effect of TENS on the autonomic function because the pain pathway and the ANS pathway are somehow correlated to each other. There is still controversy among researchers who have reported the effect of TENS on autonomic function. So the purpose of this study is to measure the effect of TENS on the ANS and to see the relation of the pain control mechanism and the change in the ANS. The results were as follows : 1) Systolic blood pressure between before and during the experiment was apt to be a little increased, but statistically there was no significant change(P>.05). 2) Systolic blood pressure between during and after 10 minutes the experiment was apt to be a little decreased, but statistically there was no significant change(P>.05). 3) Systolic blood pressure between before and after 10 minutes experiment was apt to be a little decreased, but statistically there was no significant change(P>.05). 4) Diastolic blood pressure between before and during experiment was apt to be a little increased, but statistically there was no significant change(P>.05). 5) Diastolic blood pressure between during and after 10 minutes experiment was significantly decreased(P<.05). 6) Diastolic blood pressure between before and after 10 minutes the experiment was apt to be a little decreased, but statistically there was no significant change(P>.05). 7) Heart rate between before and during the experiment was apt to be a little decreased, but statistically there was no significant change(P>.05). 8) Heart rate between during and after 10 minutes the experiment was significantly decreased(P<.05). 9) Heart rate between before and after 10 minutes the experiment was significantly decreased(P<.05). 10) Skin temperature between before and during the experiment was significantly increased(P<.05). 11) Skin temperature between during and after 10 minutes the experiment was apt to be a little increased, but statistically there was no significant change(P>.05). 12) Skin temperature between before and after 10 minutes the experiment was significantly increased(P>.05). 13) Respiratory rate between before and during the experiment was apt to be a little increased, but statistically there was no significant change(Pgt;.05). 14) Respiratory rate between during and after 10 minutes the experiment was apt to be a little decreased, but statistically there was no significant change(Pgt;.05). 15) Respiratory rate between before and after 10 minutes the experiment was apt to be a little decreased, but statistically there was no significant change(P>.05).