An evaluation of the state of time synchronization on leadership class supercomputers

We present a detailed examination of time agreement characteristics for nodes within extreme‐scale parallel computers. Using a software tool we introduce in this paper, we quantify attributes of clock skew among nodes in three representative high‐performance computers sited at three national laboratories. Our measurements detail the statistical properties of time agreement among nodes and how time agreement drifts over typical application execution durations. We discuss the implications of our measurements, why the current state of the field is inadequate, and propose strategies to address observed shortcoming

SpeechDat(E) - Eastern European Telephone Speech Databases

Contains fulltext : 76435.pdf (author's version ) (Open Access)6 p

Multivariate dependence among extremes, abrupt change and anomalies in space and time for climate applications

This paper discusses multivariate spatio-temporal dependence between extremes or abrupt change and unusual values or anomalies in the context of climate dynamics and climate change. In climate, as in many other applications, anomalies (or extremes) in one variable like sea surface temperature may be a precursor for extremes (or abrupt change) in another variable like regional precipitation. In addition, this multivariate dependence may be spatially or temporally lagged, owing to climate teleconnections . However, the anomalies may not be easily detectable and their dependence with extremes and rapid change may be difficult to quantify. This paper provides a brief review of the literature, which is followed by a description of critical gaps, both in the data or computational sciences as well as in the climate sciences. The quantification and visualization of multivariate dependence among extreme values and anomalies in highly nonlinear or stochastic systems is an emerging research area in theoretical statistics, with limited development in application areas and/or for massive or disparate space-time data. Further development is needed in these areas for multiple domains ranging from climate sciences and geography to sensor networks and national security

LAPACK users' guide: Release 1. 0

LAPACK is a transportable library of Fortran 77 subroutines for solving the most common problems in numerical linear algebra: systems of linear equations, linear least squares problems, eigenvalue problems and singular value problems. LAPACK is designed to supersede LINPACK and EISPACK, principally by restructuring the software to achieve much greater efficiency on vector processors, high-performance superscalar'' workstations, and shared-memory multi-processors. LAPACK also adds extra functionality, uses some new or improved algorithms, and integrates the two sets of algorithms into a unified package. The LAPACK Users' Guide gives an informal introduction to the design of the algorithms and software, summarizes the contents of the package, describes conventions used in the software and documentation, and includes complete specifications for calling the routines. This edition of the Users' guide describes Release 1.0 of LAPACK