Focuses on the theme 'practicality for life-extension and maintenance of plants and structures'. This work emphasises on acoustic emission (AE) research and applications. It shows that AE, as a passive, rather than an active NDT method, has drawn much attention because of its applicability to on-stream surveillance of structures.

Its applicability is limited partly because the accuracy of solutions depends on noise levels and partly because the phenomenon is usually non-reproducible. AE is expected to be a next-generation technique not only to monitor conditions but also for the repair of damaged structures, combined with an active-adaptive technique using a 'solid state actuator'. 'Smart Materials and Structures' are known in this respect. AE is considered to be a very promising technique, together with such sensing techniques as optical fiber, shape memory alloy and electro-rheological fluid. Thus, AE can play a very important roll in monitoring, evaluating and repairing structures. In this workshop, a limited number of invited papers are presented for technical discussion to review the achievements of AE research and applications in the 20th century. The proceedings are entitled Acoustic Emission - Beyond the Millennium to celebrate the new millennium, and stepping forward to a new era. The authors and topics of these review papers were selected by the editorial board.

Preface.
Selected papers.
Acoustic emission source characterization in materials (M. Enoki, T. Kishi).
Acoustic emission in rock mechanics studies (G. Manthei et al.).
Listen to your storage tanks to improve safety and reduce cost (P.T. Cole, P.J. Van De Loo).
Acoustic emission in composite materials and structures (P. Fleischmann, J.C Lenain).
Author Index.
Subject Index.