The isoelectric points of three baculoviruses, Trichoplusia ni nuclear polyhedrosis virus (NPV), T. ni granulosis virus, and Spodoptera littoralis NPV were identified by cell electrophoresis. At neutral pH polyhedra were negatively charged. T. ni NPV polyhedra were reacted with a number of reagents which could potentially attach to or degrade their surface structure. This gave information on th...

The so called ring spiral algorithm is a convenient means for gen erating and representing certain fullerenes and some other cubic poly hedra In Manolopoulos and Fowler presented a fullerene on vertices without a spiral No smaller unspirable fullerene is known In the spring of using computer Gunnar Brinkmann found the smallest cubic polyhedron without a spiral It has only vertices Here we gener...

In many applications, it suffices to know a lower bound on the distance between objects, instead of the exact distance itself, which may be more difficult to compute. Such an easy-to-compute lower bound on the distance between two nonconvex polyhedra is presented here, which doesn’t require a decomposition of the original polyhedra into convex entities. Furthermore, a suitable preprocessing of ...

We present a simple local geometric characterization of the configuration space of two polyhedra in coratact that provides a representation of all infinitesimal motions that separate them. The considered polyhedra are general in the sense that they possibly have nonconvex faces and arbitrary number of holes. The approach presented herein has two main advantages over former ones: (a) it only rel...

This paper reports a strategy for DNA self-assembly. Cross-over-based DNA nanomotifs are held together by T-junctions instead of commonly used sticky-end cohesion. We have demonstrated this strategy by assembling a DNA tetrahedron, an octahedron, and an icosahedron. The resulting DNA polyhedra contain out-pointing, short DNA hairpin spikes. These hairpins are well-structured relative to the pol...

We show how (now familiar) hierarchical representations of (convex) polyhedra can be used to answer various separation queries e ciently (in a number of cases, optimally). Our emphasis is i) the uniform treatment of polyhedra separation problems, ii) the use of hierarchical representations of primitive objects to provide implicit representations of composite or transformed objects, and iii) app...

We consider the natural generalizations of blocking and antiblocking polyhedra in infinite dimensions, and study issues related to duality and integrality of extreme points for these sets. Using appropriate finite truncations we give conditions under which complementary slackness holds for primal-dual pairs of the infinite linear programming problems associated with infinite blocking and anti-b...

We study Hamiltonian unfolding—cutting a convex polyhedron along a Hamiltonian path of edges to unfold it without overlap—of two classes of polyhedra. Such unfoldings could be implemented by a single zipper, so they are also known as zipper edge unfoldings. First we consider domes, which are simple convex polyhedra. We find a family of domes whose graphs are Hamiltonian, yet any Hamiltonian unf...

Computing over-approximations of all possible time trajectories is an important task in the analysis of hybrid systems. Sankaranarayanan et al. [20] suggested to approximate the set of reachable states using template polyhedra. In the present paper, we use a max-strategy improvement algorithm for computing an abstract semantics for affine hybrid automata that is based on template polyhedra and ...

This work describes a data structure, the Implicit Real-Vector Automaton (IRVA), suited for representing symbolically polyhedra, i.e., regions of n-dimensional space defined by finite Boolean combinations of linear inequalities. IRVA can represent exactly arbitrary convex and non-convex polyhedra, including features such as open and closed boundaries, unconnected parts, and non-manifold compone...