Memory management is a critical issue for many large object-oriented applications, but in C++ only explicit memory reclamation through the delete operator is generally available. We analyse different possibilities for memory management in C++ and present a dynamic memory management framework which can be customised to the need of specific applications. The framework allows full integration and coexistence of different memory management techniques. The Customisable Memory Management (CMM) is based on a primary collector which exploits an evolution of Bartlett's mostly copying garbage collector. Specialised collectors can be built for separate memory heaps. A Heap class encapsulates the allocation strategy for each heap. We show how to emulate different garbage collection styles or user-specific memory management techniques. The CMM is implemented in C++ without any special support in the language or the compiler. The techniques used in the CMM are general enough to be applicable also to...

This paper addresses three questions related to minimal triangulations of a three-dimensional convex polytope P . . Can the minimal number of tetrahedra in a triangulation be decreased if one allows the use of interior points of P as vertices? . Can a dissection of P use fewer tetrahedra than a triangulation? . Does the size of a minimal triangulation depend on the geometric realization of P? The main result of this paper is that all these questions have an affirmative answer. Even stronger, the gaps of size produced by allowing interior vertices or by using dissections may be linear in the number of points.

The time-dependent scattering of one-dimensional Gaussian wave packets of various energies incident on (1) a square potential barrier and (2) a square well is examined numerically, using the quantum potential introduced by Bohm. The time-dependent quantum potential is calculated in each case, and the results displayed on three-dimensional computer plots. The particle trajectories from different initial positions within the wave packet are also shown, giving a detailed description of reflection and tunneling in terms of individual processes. The wider implications of this analysis are also briefly considered. 1.