to be done in this area. Face recognition is a problem that scarcely clamoured for attention before the computer age but, having surfaced, has involved a wide range of techniques and has attracted the attention of some fine minds (David Mumford was a Fields Medallist in 1974). This singular application of mathematical modelling to a messy applied problem of obvious utility and importance but with no unique solution is a pretty one to share with students: perhaps, returning to the source of our opening quotation, we may invert Duncan's earlier observation, 'There is an art to find the mind's construction in the face!'.

Linear and nonlinear waves, by G. B. Whitham. Pp.636. £50. 1999. ISBN 0 471 35942 4 (Wiley).

We introduce TestU01, a software library implemented in the ANSI C language, and offering a collection of utilities for the empirical statistical testing of uniform random number generators (RNGs). It provides general implementations of the classical statistical tests for RNGs, as well as several others tests proposed in the literature, and some original ones. Predefined tests suites for sequences of uniform random numbers over the interval (0, 1) and for bit sequences are available. Tools are also offered to perform systematic studies of the interaction between a specific test and the structure of the point sets produced by a given family of RNGs. That is, for a given kind of test and a given class of RNGs, to determine how large should be the sample size of the test, as a function of the generator's period length, before the generator starts to fail the test systematically. Finally, the library provides various types of generators implemented in generic form, as well as many specific generators proposed in the literature or found in widely used software. The tests can be applied to instances of the generators predefined in the library, or to user-defined generators, or to streams of random numbers produced by any kind of device or stored in files. Besides introducing TestU01, the article provides a survey and a classification of statistical tests for RNGs. It also applies batteries of tests to a long list of widely used RNGs.

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TestU01: A C library for empirical testing of random number generators

Several new numerical methods for compressible shear-layer simulations

Dispersion-managed solitons in fibre systems and lasers

Book review: Applied cryptography: Protocols, algorithms, and source code in C

A new test for randomness and its application to some cryptographic problems

Classification of difference schemes of gas dynamics by the method of differential approximation—II. Two-dimensional case

The problem on active media [1, 2] capable of absorbing and amplifying an external disturbance and then reemitting it in the form of an acoustic pulse is one of the problems of the so-called acoustic laser (acoustic analogue of laser systems). As was shown in [3] by numerical analysis of one-dimensional cases, bubble systems, both passive and containing explosive gaseous mixtures, can be treated as active media. In such media, an excitation caused by interactions with shock waves can lead to significantly amplifying the wave field and generating an intense shock pulse.

Generation of Shock Waves by Spherical Bubble Clusters in a Liquid

Hierarchy of nonlinear models of the hydrodynamics of long surface waves

The discussed challenge and its prospects in mining geoinformation science are connected with Big Data concept—flows of large sets of various data on mining. The authors describe Big Data technology and its general implementation on mini-clusters using Hadoop and MapReduce with case studies presented.

Yu. I. Shokin

Papers

A new test for randomness and its application to some cryptographic problems

Classification of difference schemes of gas dynamics by the method of differential approximation—II. Two-dimensional case

Generation of Shock Waves by Spherical Bubble Clusters in a Liquid

Hierarchy of nonlinear models of the hydrodynamics of long surface waves

Mining information science and Big Data concept for integrated safety monitoring in subsoil management