We address the problem of constructing numerical integrators for nonholonomic Lagrangian systems that enjoy appropriate discrete versions of the geometric properties of the continuous flow, including the preservation of energy. Building on previous work on time-dependent discrete mechanics, our approach is based on a discrete version of the Lagrange-d’Alembert principle for nonautonomous systems.

We introduce a bipolarly extended veto principle – a positive, as well as negative, large performance differences polarization – which allows us to extend the definition of the classical outranking relation in such a way that the identity between its asymmetric part and its codual relation is preserved.

The amount of content from digital origin permanently increases. The short lifespan of digital media makes it necessary to develop strategies to preserve its content for future use. Not only electronic documents, pictures and movies have to be preserved, also interactive content like digital art or video games have to be kept “alive” for future generations. In this paper we discuss strategies f...

In a paper called Definiteness and Knowability, Timothy Williamson investigates the question of whether one must accept that vagueness is an epistemic phenomenon if one adopts classical logic and a disquotational principle for truth. Some have thought that one must not, and have argued that classical logic and the disquotational principle can be preserved without accepting that vagueness is an ...

Methods that might work are not good enough; what is preserved today should be reliably useful whenever someone wants it. Here, “reliably” is intended to include “without error introduced after the data leaves the purported author’s control.” Prior proposals—called “transformative migration” and “preservation emulation”—fail because what they save is confounded with details about today’s inform...

The relation between figural and kimematic aspects of movement was studied in handwriting and drawing. It was found that, throughout the movement, the tangential velocity. V is proportional to the radius of curvature r of the trajectory: V= kr, or, equivalently, that the angular velocity is constant: dalpha(t)/dt = K. However, the constant k generally takes several distinct values during the mo...