• The Journal of Industrial Distribution & Business
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• v.15 no.5
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• pp.17-27
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• 2024

Purpose: The renminbi (RMB) has appreciated alongside the elevation of China's economic status, leading to increased exchange rate volatility. Moreover, China's medical industry saw a surge in import and export trade volume, with trade related to epidemic prevention and control in the medical sector significantly increasing its share. The medical device trade, in particular, occupies a substantial portion of this trade. Research design, data and methodology: This paper focuses on the import and export value of medical devices in the medical industry as a case study to explore the impact of RMB exchange rate fluctuations on the import and export trade of the medical industry during the pandemic. Additionally, it investigates whether the import and export trade of the medical industry can be a contributing factor to the fluctuations in the RMB exchange rate. Results: Through an empirical study on the import and export values of medical devices in the medical industry over the past three years, as well as the RMB exchange rate, this paper establishes a VAR model and conducts a series of tests including stationarity tests and cointegration tests. Conclusions: The conclusion is that fluctuations in the RMB exchange rate have a long-term impact on China's medical industry's import and export trade.

• Journal of Radiation Protection and Research
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• v.31 no.1
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• pp.17-23
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• 2006

The purpose of this study is to provide the guidance necessary for making a selection of error distributions by analyzing influence of statistical distribution for a type of bioassay measurement error on the intake estimation. For this purpose, intakes were estimated using maximum likelihood method for cases that error distributions are normal and lognormal, and comparisons between two distributions for the estimated intakes were made. According to the results of this study, in case that measurement results for lung retention are somewhat greater than the limit of detection it appeared that distribution types have negligible influence on the results. Whereas in case of measurement results for the daily excretion rate, the results obtained from assumption of a lognormal distribution were 10 % higher than those obtained from assumption of a normal distribution. In view of these facts, in case where uncertainty component is governed by counting statistics it is considered that distribution type have no influence on intake estimation. Whereas in case where the others are predominant, it is concluded that it is clearly desirable to estimate the intake assuming a lognormal distribution.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1803-1805
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• 1998

Electron temperature, electron density and electron energy distribution function were measured in Radio-Frequency Inductively Coupled Plasma(RFICP) using a probe method. Measurements were conducted in argon discharge for pressure from 10 mTorr to 40 mTorr and input rf power from 100W to 600W and flow rate from 3 sccm to 12 sccm. Spatial distribution electron temperature and electron density and electron energy distribution function were measured for discharge with same aspect ratio(R/L=2). Electron temperature was found to depend on pressure, but only weakly on power. Electron density and electron energy distribution function strongly depended on both pressure and power. Electron density and electron energy distribution function increased with increasing flow rate. Radial distribution of the electron density and electron energy distribution function were peaked in the plasma center. Normal distribution of the electron density electron energy distribution function were peaked in the center between quartz plate and substrate. These results were compared to a simple model of ICP, then we found out the generation mechanism of Radio-Frequency Inductively Coupled Plasma.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.4
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• pp.82-86
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• 1999

Electron Energy Distribution Function(EEDF) were treasured In Radio-Frequency Inductively Coupled Plasma(RFlCP) using a probe rrethocl Measurerrents were conducted in argon discharge for pressure from 10[mTorr] to 4O[mTorr] and input rf power from 100[W] to 600[W] and flow rate from 3[sccm] to 12[sccm]. Spatial distribution of electron energy distribution function were measured for discharge with same aspoct ratio (R/L=2). Electron energy distribution function strongly depended on both pressure and power. Electron energy distribution function increased with increasing flow rate. Radial distribution of the electron energy distribution function were peaked in the plasma center. Normal distribution of the electron energy distribution function were peaked in the center between quartz plate and substrate. From the results, we can find out the generation mechanism of Radio Frequency Inductively Coupled Plasma. And these results contribute the application of a simple Inductively Coupled Plasma(ICP).a(ICP).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.2
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• pp.146-151
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• 2005

Some distributions have been used for diagnosing the lead time demand distribution in inventory system. In this paper, we describe the negative binomial distribution as a suitable demand distribution for a specific retail inventory management application. We here assume that customer order sizes are described by the Poisson distribution with the random parameter following a gamma distribution. This implies in turn that the negative binomial distribution is obtained by mixing the mean of the Poisson distribution with a gamma distribution. The purpose of this paper is to give an interpretation of the negative binomial demand process by considering the sources of variability in the unknown Poisson parameter. Such variability comes from the unknown demand rate and the unknown lead time interval.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.79-84
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• 2005

Some distributions have been used for diagnosing the lead time demand distribution in inventory system. In this paper, we describe the negative binomial distribution as a suitable demand distribution for a specific retail inventory management application. We here assume that customer order sizes are described by the Poisson distribution with the random parameter following a gamma distribution. This implies in turn that the negative binomial distribution is obtained by mixing the mean of the Poisson distribution with a gamma distribution. The purpose of this paper is to give an interpretation of the negative binomial demand process by considering the sources of variability in the unknown Poisson parameter. Such variability comes from the unknown demand rate and the unknown lead time interval.

• Proceedings of the Korean Magnestics Society Conference
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• 1997.11a
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• pp.96-97
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• 1997

• Communications for Statistical Applications and Methods
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• v.19 no.4
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• pp.629-638
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• 2012

We propose some methods to obtain optimal thresholds and classification functions by using various cutoff criterion based on the bivariate ROC curve that represents bivariate cumulative distribution functions. The false positive rate and false negative rate are calculated with these classification functions for bivariate normal distributions.

• International Journal of Reliability and Applications
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• v.2 no.3
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• pp.199-207
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• 2001

The failure rate functions between successive failures are of concatenated form. We allow the parameters of failure rate function change after a certain failure and its fixing. We confine out attention to a model wherein the interfailure times are described by its failure rate function. We suggest an adaptive failure rate function with a change-point under the assumption that interfailure times are record value statistics from a Weibull distribution. The proposed model will be applied through a practical example of software failure data.

• Journal of Korean Society for Quality Management
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• v.31 no.3
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• pp.193-204
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• 2003

In this paper, we consider a periodic preventive maintenance(PM) policy in which each PM reduces the hazard rate but remains the pattern of hazard rate unchanged. And the system undergoes only minimal repairs at failures between PM's. The expected cost rate per unit time is obtained. The optimal number N of PM and the optimal period x, which minimize the expected cost rate per unit time are discussed. Explicit solutions for the optimal periodic PM are given for the Weibull distribution case.