Extracting the cutoff frequency in the gravitational-wave spectrum of black hole-neutron star mergers

The location of the cutoff in the gravitational-wave spectrum of black hole-neutron star mergers is correlated strongly with the neutron-star radius for the case that the neutron star is disrupted by the black hole during the merger. However, the modulation which appears in the spectrum due to the mode mixing makes it difficult to measure the cutoff frequency if gravitational waves are observed from inclined direction or the binary is precessing. In this letter, we show that the cutoff frequency can be measured even in such situations with a method we have recently proposed to reconstruct the face-on waveforms only from the strain observed from a particular direction. We show that the systematic error in the measurement of the neutron-star radius can be reduced to $\lesssim 5\%$ for the case that tidal disruption of the neutron star occurs significantly.Comment: 6 pages, 2 figure

Extracting the orbital axis from gravitational waves of precessing binary systems

We present a new method for extracting the instantaneous orbital axis only from gravitational wave strains of precessing binary systems observed from a particular observer direction. This method enables us to reconstruct the co-precessing frame waveforms only from observed quantities for the ideal case that the signal-to-noise ratio is high enough to analyze the waveforms directly. Specifically, we do not assume knowledge of the time evolution of the instantaneous orbital axis and the co-precessing waveforms before analyzing the data in our method. We test and measure the accuracy of our method using the numerical relativity simulation data of precessing binary black holes taken from the SXS Catalog. We show that the direction of the orbital axis is extracted within $\approx0.02~{\rm rad}$ error from gravitational waves emitted during the inspiral phase. The co-precessing waveforms are also reconstructed with high accuracy; the mismatch (assuming white noise) between them and the original co-precessing waveforms is typically a few times $10^{-3}$ including the merger-ringdown phase, and can be improved by an order of magnitude focusing only on the inspiral waveform. In this method, the co-precessing frame waveforms are not only the purely technical tools for understanding the complex nature of precessing waveforms but also direct observables.Comment: 12 pages, 8 figures, 1 table, published in PR

ESTIMATION OF THE EFFICIENCY OF JAPANESE HOSPITALS USING A DYNAMIC AND NETWORK DATA ENVELOPMENT ANALYSIS MODEL

Workshop 2013 on Dynamic and Network DEA (January 29-30, 2013)This study evaluates the policy effect of the reformation of municipal hospitals in Japan. We focused on the efficiency improvement of not only the hospital itself but also separate internal organizations of a hospital. Hospitals have two heterogeneous internal organizations: the medical-examination section and administration section. The administration section carries out business management and the medical-examination section provides medical care services. We employed a dynamic and network data envelopment analysis model. The model makes it possible to estimate both the efficiencies of separate organizations and the dynamic changes of the efficiencies simultaneously. We found that there are positive policy effects. Additionally, we should focus on the administration section rather than the medical-examination section in reforming municipal hospitals in Japan.This workshop is supported by JSPS KAKENHI Grant Number 22310092 under the title “Theory and Applications of Dynamic DEA with Network Structure.

ESTIMATION OF THE EFFICIENCY OF JAPANESE HOSPITALS USING A DYNAMIC AND NETWORK DATA ENVELOPMENT ANALYSIS MODEL

This workshop is supported by JSPS KAKENHI Grant Number 22310092 under the title “Theory and Applications of Dynamic DEA with Network Structure.”This study evaluates the policy effect of the reformation of municipal hospitals in Japan. We focused on the efficiency improvement of not only the hospital itself but also separate internal organizations of a hospital. Hospitals have two heterogeneous internal organizations: the medical-examination section and administration section. The administration section carries out business management and the medical-examination section provides medical care services. We employed a dynamic and network data envelopment analysis model. The model makes it possible to estimate both the efficiencies of separate organizations and the dynamic changes of the efficiencies simultaneously. We found that there are positive policy effects. Additionally, we should focus on the administration section rather than the medical-examination section in reforming municipal hospitals in Japan.Workshop 2013 on Dynamic and Network DEA (January 29-30, 2013)conference pape

Estimation of mutual information via quantum kernel method

Recently, the importance of analysing data and collecting valuable insight efficiently has been increasing in various fields. Estimating mutual information (MI) plays a critical role to investigate the relationship among multiple random variables with a nonlinear correlation. Particularly, the task to determine whether they are independent or not is called the independence test, whose core subroutine is estimating MI from given data. It is a fundamental tool in statistics and data analysis that can be applied in a wide range of application such as hypothesis testing, causal discovery and more. In this paper, we propose a method for estimating mutual information using the quantum kernel. We investigate the performance under various problem settings, such as different sample size or the shape of the probability distribution. As a result, the quantum kernel method showed higher performance than the classical one under the situation that the number of samples is small, the variance is large or the variables posses highly non-linear relationships. We discuss this behavior in terms of the central limit theorem and the structure of the corresponding quantum reproducing kernel Hilbert space.Comment: 20 pages, 10 figure

How successful was the policy of reformation of municipal hospitals in Japan? : Estimation of the efficiency of Japanese hospitals using a dynamic and network data envelopment analysis

Workshop 2015 -Advances in DEA Theory and Applications (December 1-2, 2015)The purpose of this study was to perform an evaluation of the policy effect of the current reform of Japan’s municipal hospitals. We focused on efficiency improvements both within hospitals and within two separate internal hospital organizations. Hospitals have two heterogeneous internal organizations: the medical examination division and administration division. We extend observation time from 3years to 6years to compare to previous version of this study. We also added new variable MRI as link variable. Results showed that the average overall efficiency obtained with the DN-DEA model was 0.829 for 2007. The change in efficiency scores from 2007 to 2012 was slightly lower. The average estimated efficiency of both the administration division and medical-examination division decreased. We were unable to find any significant improvement in efficiency despite the reform policy. Thus, there are no positive policy effects despite the increased financial support from the central government.The workshop is supported by JSPS (Japan Society for the Promotion of Science), Grant-in-Aid for Scientific Research (B), #25282090, titled “Studies in Theory and Applications of DEA for Forecasting Purpose.本研究はJSPS科研費 基盤研究(B) 25282090の助成を受けたものです

Rethinking The Political System of the Jöchid

The aim of this paper is to reconstruct the history of the Jöchid, placing emphasis on the “inner sources of the Jöchid”, especially on the Chingīz-nāma. First, we re-examine the essence of the term “Golden Horde”, and make an attempt to point out that the appellation “Golden Horde” used for the Jöchid may go back to earlier times than the late 16th century. Secondly, it is demonstrated that the Jöchid had been divided into Right and Left Wings after the reign of Toqtagha at the latest and this structure continued even after the unification of both wings by Toqtamïsh, a fact that historians in the Timurid Empire were also well aware of. Thirdly, the study shows that, at least by the late 14th century, it was recognised that the “White Horde” referred to the Right Wing or the entire Jöchid, while the “Blue Horde” to the Left Wing

Analyses of Southerly Winds along the Kitakami Basin when the Yamase Prevails

The Yamase is a cold, humid, northeasterly wind blowing toward the coast on the Pacific side of the Tohoku region of Japan during summer. However, the Yamase blows in a southerly direction in the Kitakami Basin. Inthis study, analyses of data and numerical experiments using the Weather Research and Forecasting(WRF) model were conducted to determine the reason for this southerly direction. The results of numerical experiments indicated that the Yamase is southerly in the Kitakami Basin where theactual topography is reduced to 90% of the average terrain height. Meanwhile, it is easterly in areas of the Kitakami Basin when the topography is reduced to 80% of the average terrain height. The results of numerical experiments were consistent with those of mechanical analyses using the Foude number and Rossby number. Analyses of the Yamase in the Kitakami Basin therefore suggest that its characteristics are influenced by topographic obstacles and gravitational flow