著者

Kenji KAWAGUCHI Tomoaki UCHIYAMA Ken MURAMATSU

出版者

一般社団法人 日本機械学会

雑誌

Journal of Power and Energy Systems (ISSN:18813062)

巻号頁・発行日

vol.6, no.3, pp.378-393, 2012 (Released:2012-08-10)

参考文献数

25

被引用文献数

10

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Fault Tree and Event Tree analysis is almost exclusively relied upon in the assessments of seismic Core Damage Frequency (CDF). In this approach, Direct Quantification of Fault tree using Monte Carlo simulation (DQFM) method, or simply called Monte Carlo (MC) method, and Binary Decision Diagram (BDD) method were introduced as alternatives for a traditional approximation method, namely Minimal Cut Set (MCS) method. However, there is still no agreement as to which method should be used in a risk assessment of seismic CDF, especially for uncertainty analysis. The purpose of this study is to examine the efficiencies of the three methods in uncertainty analysis as well as in point estimation so that the decision of selecting a proper method can be made effectively. The results show that the most efficient method would be BDD method in terms of accuracy and computational time. However, it will be discussed that BDD method is not always applicable to PSA models while MC method is so in theory. In turn, MC method was confirmed to agree with the exact solution obtained by BDD method, but it took a large amount of time, in particular for uncertainty analysis. On the other hand, it was shown that the approximation error of MCS method may not be as bad in uncertainty analysis as it is in point estimation. Based on these results and previous works, this paper will propose a scheme to select an appropriate analytical method for a seismic PSA study. Throughout this study, SECOM2-DQFM code was expanded to be able to utilize BDD method and to conduct uncertainty analysis with both MC and BDD method.

著者

Yuki Kato Miho Shimizu Shinsuke Hori Kenta Ushida Yoshinori Yamamoto Ken Muramatsu Ryo Momosaki

出版者

THE JAPANESE ASSOCIATION OF RURAL MEDICINE

雑誌

Journal of Rural Medicine (ISSN:1880487X)

巻号頁・発行日

vol.17, no.2, pp.73-78, 2022 (Released:2022-04-06)

参考文献数

19

被引用文献数

2

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Objectives: This study aimed to determine the relationship between the number of board-certified physiatrists and the amount of inpatient rehabilitation delivered.Materials and Methods: We analyzed open data from 2017 in the National Database of Health Insurance Claims and Specific Health Checkups of Japan and compared the volume of inpatient rehabilitation services between prefectures to examine regional disparities. We also examined the relationship between the volume of rehabilitation services provided and the number of board-certified physiatrists.Results: The population-adjusted number of inpatient rehabilitation units per prefecture ranged from a maximum of 659,951 to a minimum of 172,097, a disparity of 3.8-fold. The population-adjusted number of board-certified physiatrists was 4.8 in the highest region and 0.8 in the lowest region, a disparity of 5.8-fold. The population-adjusted number of board-certified physiatrists was significantly correlated with the population-adjusted total number of inpatient rehabilitation units (r=0.600, P<0.001). Correlations were between the number of board-certified physiatrists and the number of rehabilitation units in cerebrovascular and orthopedic services, but not in cardiovascular, respiratory, or oncology services.Conclusion: Large regional disparities manifested in the amount of inpatient rehabilitation provided in Japan. An association was found between the number of board-certified physiatrists and rehabilitation units delivered. It may be necessary to train more BCPs in regions with fewer units to eliminate these disparities.