• 한국국방경영분석학회지
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• 제10권2호
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• pp.61-73
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• 1984

A block replacement policy using items with different reliability is discussed. We divide system unit failure modes into two modes and use less reliable unit when operating unit fails near the planned preventive replacement time. In this policy, item A has two failure modes. Mode-1 failure is removed by minimal repair, mode-2 failure by replacement. If mode-2 failure of item A happens in (0, $T-{\delta}$), failure item A is replaced by new item A. If mode-2 failure of item A happens in ($T-{\delta}$, T), failure item A is replaced by new item B. Item B should be cheaper and less durable than item A. Under this policy, we determine the preventive replacement interval $T^{*}$ and the interval ${\delta}^{*}$ of item B replacement which minimize the cost rate per unit time.

• 대한예방한의학회지
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• 제18권1호
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• pp.103-111
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• 2014

Objective : Understanding the state of sanitation policy during the period of Japanese colonization of Korea. Method : Analyze 'Slang on hygiene practices' found in Korean medical journal "ChoSunEuiHakGye" that published in the period of Japanese colonization. And analyze articles that were same theme. Results : Japanese colonial policy regards the colony people's old adage of health as outrageous things. Japanese colonial police demands don't use old adage of health because it is obstruction to colonial hygiene policy. Conclusion : The Japanese occupation health administration led by the Japanese police considered Korean people as significant. And they regarded old adage of health as harmful habits. In addition, the knowledge derived from traditional Korean medicine was turned away outrageous things. Traditional Korean medicine knowledge lost the chance of renewal.

• 보건행정학회지
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• 제27권2호
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• pp.114-120
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• 2017

The hospital standardized mortality ratio (HSMR) is a widely used generic measure for assessing quality of hospital care in many countries. However, the validity of HSMR as a quality indicator is still controversial. We critically reviewed characteristics of HSMR and suggested how to use HSMR as a quality indicator in the Korean setting. The association between HSMR and other quality measures of hospital care is inconclusive. In addition current HSMR model has shortcomings in risk adjustment because of the lack of clinical data, accuracy of disease coding, coding variation among hospitals, end-of-life care issues, and so on. Therefore, HSMR should be used as an indicator for improvement, not for judgement such as public reporting and pay-for-performance. More efforts will be needed to tackle practical and methodological weaknesses of HSMR in the Korean setting.

• 산업경영시스템학회지
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• 제45권3호
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• pp.78-89
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• 2022

The purpose of this study was to propose useful suggestion by analyzing preventive replacement policy under which there are minor and major failure. Here, major failure is defined as the failure of system which causes the system to stop working, however, the minor failure is defined as the situation in which the system is working but there exists inconvenience for the user to experience the degradation of performance. For this purpose, we formulated an expected cost rate as a function of periodic replacement time and the number of system update cycles. Then, using the probability and differentiation theory, we analyzed the cost rate function to find the optimal points for periodic replacement time and the number of system update cycles. Also, we present a numerical example to show how to apply our model to the real and practical situation in which even under the minor failure, the user of system is not willing to replace or repair the system immediately, instead he/she is willing to defer the repair or replacement until the periodic or preventive replacement time. Optimal preventive replacement timing using two variables, which are periodic replacement time and the number of system update cycles, is provided and the effects of those variables on the cost are analyzed.

• Journal of Preventive Medicine and Public Health
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• 제52권1호
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• pp.41-50
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• 2019

Objectives: The aim of this study was to investigate cancer patients' utilization of tertiary hospitals in Seoul before and after the benefit expansion policy implemented in 2013. Methods: This was a before-and-after study using claims data of the Korean National Health Insurance Service from 2011 to 2016. The unit of analysis was inpatient episodes, and inpatient episodes involving a malignant neoplasm (International Classification of Diseases, Tenth Revision codes: C00-C97) were included in this study. The total sample (n=5 565 076) was divided into incident cases and prevalent cases according to medical use due to cancer in prior years. The tertiary hospitals in Seoul were divided into two groups (the five largest hospitals and the other tertiary hospitals in Seoul). Results: The proportions of the incident and prevalent episodes occurring in tertiary hospitals in Seoul were 34.9% and 37.2%, respectively, of which more than 70% occurred in the five largest hospitals in Seoul. Utilization of tertiary hospitals in Seoul was higher for inpatient episodes involving cancer surgery, patients with a higher income, patients living in areas close to Seoul, and patients living in areas without a metropolitan city. The utilization of the five largest hospitals increased by 2 percentage points after the policy went into effect. Conclusions: The utilization of tertiary hospitals in Seoul was concentrated among the five largest hospitals. Future research is necessary to identify the consequences of this utilization pattern.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1999년도 제51차 추계 학술대회 연제집
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• pp.123-124
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• 1999

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1995년도 제47차 추계 학술대회 연제집
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• pp.191-192
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• 1995

• 보건행정학회지
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• 제26권3호
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• pp.153-154
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• 2016

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1999년도 제51차 추계 학술대회 연제집
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• pp.244-245
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• 1999

• International Journal of Reliability and Applications
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• 제9권1호
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• pp.113-122
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• 2008

In this paper, we consider a periodic preventive maintenance policy in which each preventive maintenance reduces the hazard rate of amount proportional to the failure intensity, which increases since the system started to operate. And the effect of preventive maintenance at each preventive maintenance epoch is different. The expected cost rate per unit time for the proposed model is obtained. We discuss the optimal number N of the periodic preventive maintenance and the optimal period x, which minimize the expected cost rate per unit time and obtain the optimal preventive maintenance schedule for given cost structures of the model. A numerical example is given for the purpose of illustrating our results when the failure time distribution is Weibull distribution.