Let X be a finite set of v elements, called points, and let β be a finite family of distinct k-subsets of X , called blocks. Then the pair D = (X ,β) is called a t-design with parameters (v,k,λ) if any t-subset of X is contained in exactly λ members of β. If λi denotes the number of blocks containing i points, i = 0,1,2, . . . , t−1, then λi is independent of the choice of the i points and λi (...

Since most current scene understanding approaches operate either on the 2D image or using a surface-based representation, they do not allow reasoning about the physical constraints within the 3D scene. Inspired by the “Blocks World” work in the 1960’s, we present a qualitative physical representation of an outdoor scene where objects have volume and mass, and relationships describe 3D structure...

In this paper, we describe an improvement on the task of giving instructions to robots in a simulated block world using unrestricted natural language commands.

Standard tours combined with lack of information make many tourists miss some important experiences a destination has to offer. The target of the Dynamic Tour Guide (DTG) is to discover Tour Building Blocks (TBB), e.g. attractions like sights or restaurants, dependent on the actual context which is defined by personal interests, location and schedule of a tourist. It determines current informat...

In this paper we are concerned with the problem of learning how to solve planning problems in one domain given a number of solved instances. This problem is formulated as the problem of inferring a function that operates over all instances in the domain and maps states and goals into actions. We call such functions generalized policies and the question that we address is how to learn suitable r...

We describe a natural revision-based logical modelling for evolvable software. An evolvable component comprises two parts: a supervising process and its supervisee subcomponent. The supervisor’s role is to monitor and possibly evolve its supervisee, where evolutionary change may be determined purely internally from observations made by the supervisor of the supervisee’s behaviour, or may be a r...

The purpose of this review is to discuss recent developments occurring at the interface of cosmology with string and M-theory. We begin with a short review of 1980s string cosmology and the Brandenberger-Vafa mechanism for explaining spacetime dimensionality and then introduce the Pre-Big-Bang scenario (PBB), the work of Hořava-Witten and Lukas, Ovrut and Waldram, and end with a discussion of t...

We show that (massive) D = 10 type IIA supergravity possesses a hidden rigid D 9 ≡ SO(9, 9) symmetry and a hidden local SO(9) × SO(9) symmetry upon dimensional reduction to one (time-like) dimension. We explicitly construct the associated locally supersymmetric Lagrangian in one dimension, and show that its bosonic sector, including the mass term, can be equivalently described by a truncation o...

In her paper ([4]), Janice Glasgow adresses many important advantages that imagery models can offer over sentential models such as predicate logic. In this response, we point out another important advantage of imagery with respect to the formulation of models. Consider the problem of reasoning about placing two-dimensional polygonal “blocks” in a space, illustrated in Figure 1. For purposes suc...

This is a summary of a course given at the Fourth Mexican School on Gravitation and Mathematical Physics on some aspects of PBB cosmology. After introductory remarks the lectures concentrate on some amusing consequences derived from the symmetries of the string theory with respect to such classical concepts as isotropy and homogeneity. The extra dimensions and the symmetries of the M theory are...