In the s Bennett introduced computational depth as a formal measure of the amount of computational history that is evident in an object s structure In particular Bennett identi ed the classes of weakly deep and strongly deep sequences and showed that the halting problem is strongly deep Juedes Lath rop and Lutz subsequently extended this result by de ning the class of weakly useful sequences an...

This paper investigates the structure of ESPACE under nonuniformTuring reductions that are computed by polynomial size circuits P Poly Turing reductions A Small Span Theorem is proven for such reductions This result says that every language A in ESPACE satis es at least one of the following two conditions i The lower P Poly Turing span of A consisting of all languages that are P Poly Turing red...

The resource-bounded measures of complexity classes are shown to be robust with respect to certain changes in the underlying probability measure. Speci cally, for any real number > 0, any uniformly polynomial-time computable sequence ~ = ( 0; 1; 2; : : : ) of real numbers (biases) i 2 [ ; 1 ], and any complexity class C (such as P, NP, BPP, P/Poly, PH, PSPACE, etc.) that is closed under positiv...

In this paper we explore a number of ideas for enhancing the techniques of genetic programming in the context of a very simple test environment that nevertheless possesses some degree of algorithmic subtlety. We term this genetic programming environment plus-onerecall-store (PORS). This genetic programming environment is quite simple having only a pair of terminals and a pair of operations. The...

KIVIEW is an object-oriented browsing interface to databases. The underlying internal model is a semantic network, defined via a collection of triplet facts which are governed by a small set of integrity requirements. KIVIEW's only ezternal structure is a display, called uiew, that presents all the information that is pertinent to a given object. KIVIEW features two kinds of activity, called na...

most of the year kept prospectors at bay, there was little to regulate. But as global warming thaws the ocean’s layers, oil giants, shipping companies and even the odd enterprising tourist operator are casting their eyes towards the high north. The biggest boom could be in oil and gas. The US Geological Survey surprised some experts when it declared that a quarter of the world’s undiscovered re...