Many psychological tasks vary in difficulty with the complexity of the stimulus objects involved. Complex visual objects are not only harder to reproduce from memory than simple ones (4, 6), but also harder to learn by name (4, 7) and to match (11). Complexity is an ill-defined variable, however. No two of the experiments referenced above employ exactly the same operations of physical measureme...

A half-plane probe through a polygon measures the area of intersection between a half-plane and the polygon. We dev elop techniques based on xray probing to determine convex n-gons in 7n + 7 half-plane probes. We also show n + 1 half-plane probes are sufficient to verify a specified convex polygon and prove linear lower bounds for determination and verification.

Strong visibility is a generalization of standard visibility, defined with respect to a fixed set of line orientations. We investigate computational properties of this generalized visibility, as well as the related notion of strong convexity. In particular, we describe algorithms for the following tasks: 1. Testing the strong visibility of two points in a polygon and the strong convexity of a p...

Let M be an m-sided simple polygon and N be an n-sided polygon with holes. In this paper we consider the problem of computing the feasible region i.e., the set of all placements by translation of M so that M lies inside N without intersecting any hole. First we propose an O(mn 2) time algorithm for computing the feasible region for the case when M is a monotone polygon. Then we consider the gen...