Over 20 years ago we reported for the first time the presence of mechanical abnormalities in the contraction pattern of patients with the long QT syndrome (LQTS), showing the presence both of rapid early contraction and of an extended ‘plateau’ phase clearly visible at M-mode Doppler before rapid relaxation. These abnormalities were almost absent in controls and more prevalent among symptomatic...

We propose sparse DCC-GARCH and BEKK-GARCH models based on L 1 ${L}_{1}$ regularization. use the to study daily return volatility correlation spillovers for 24 constituents of Bloomberg commodity index in period 2000–2018. The outperform diagonal out-of-sample terms model fit other criteria. also test whether higher visibility metals energy markets compared with agricultural commodities affects...

This paper proposes new methods for the econometric analysis of outlier contaminated multivariate conditionally heteroscedastic time series. Robust alternatives to the Gaussian quasi-maximum likelihood estimator are presented. Under elliptical symmetry of the innovation vector, consistency results for M-estimation of the general conditional heteroscedasticity model are obtained. We also propose...

T. Antoni a, W. D. Apel b, A.F. Badea a,1, K. Bekk b, A. Bercuci b,1, H. Blümer b,a, H. Bozdog b, I. M. Brancus c, C. Büttner a, A. Chilingarian d, K. Daumiller a, P. Doll b, R. Engel b, J. Engler b, F. Feßler b, H. J. Gils b, R. Glasstetter a, R. Haeusler a, A. Haungs b, D. Heck b, J. R. Hörandel a, A. Iwan a,2, K.-H. Kampert a,b, H. O. Klages b, G. Maier b,3, H. J. Mathes b, H. J. Mayer b, J....

The purpose of the paper is to discuss ten things potential users should know about the limits of the Dynamic Conditional Correlation (DCC) representation for estimating and forecasting time-varying conditional correlations. The reasons given for caution about the use of DCC include the following: DCC represents the dynamic conditional covariances of the standardized residuals, and hence does n...

The purpose of the paper is to discuss ten things potential users should know about the limits of the Dynamic Conditional Correlation (DCC) representation for estimating and forecasting time-varying conditional correlations. The reasons given for caution about the use of DCC include the following: DCC represents the dynamic conditional covariances of the standardized residuals, and hence does n...