839746
Roadmap for enhanced languages and methods to aid verification
This roadmap describes ways that researchers in four areas---specification languages, program generation, correctness by construction, and programming languages---might help further the goal of verified software. It also describes what advances the "verified software" grand challenge might anticipate or demand from work in these areas. That is, the roadmap is intended to help foster collaboration between the grand challenge and these research areas.A common goal for research in these areas is to establish language designs and tool architectures that would allow multiple annotations and tools to be used on a single program. In the long term, researchers could try to unify these annotations and integrate such tools.
13298925
Collection analysis for Horn clause programs
We consider approximating data structures with collections of the items that they contain. For examples, lists, binary trees, tuples, etc, can be approximated by sets or multisets of the items within them. Such approximations can be used to provide partial correctness properties of logic programs. For example, one might wish to specify than whenever the atom sort(t,s) is proved then the two lists t and s contain the same multiset of items (that is, s is a permutation of t). If sorting removes duplicates, then one would like to infer that the sets of items underlying t and s are the same. Such results could be useful to have if they can be determined statically and automatically. We present a scheme by which such collection analysis can be structured and automated. Central to this scheme is the use of linear logic as a computational logic underlying the logic of Horn clauses
657782
Experiences with an Architecture for Intelligent, Reactive Agents
This paper briefly describes a robot architecture that has been under development for the last eight years. This architecture uses several levels of abstraction and description languages that are compatible between levels. The makeup of the architecture helps to coordinate planful activities with real-time behaviors for dealing with dynamic environments. In recent years, many architectures have been created with similar attributes. The two features that distinguish this architecture from most of those are: 1) a variety of useful software tools have been created to help implement this architecture on multiple real robots; and 2) this architecture, or parts of it have been implemented on over half a dozen very different robot systems using a variety of processors, operating systems, effectors and sensor suites.
27853952
A non-greedy approach to tree-structured clustering
Abstract We propose a new interdisciplinary approach for the hard optimization problem of tree-structured clustering, wherein the imposition of structural constraints on the solution drastically reduces the complexity of classifying data. The method, derived with analogy to statistical physics, performs a global optimization over the entire tree. Experimentation with non-trivial examples shows that our approach consistently outperforms greedy methods and avoids local minima that may trap them.
1440056
Concerning the achromatic number of graphs
Abstract The achromatic number of a graph G is the largest number of colors that can be assigned to the vertices of G so that (i) adjacent vertices are assigned different colors, and (ii) any two different colors are assigned to some pair of adjacent vertices. We study the achromatic number from the point of view of computational complexity. We show that, for each fixed integer n , there is an algorithm which, for an arbitrary graph G , determines in time O (| E ( G )|) whether the achromatic number of G is at least n . In contrast to this, we show that when n is part of the input, the problem is NP-complete even when restricted to bipartite graphs. The complexity of determining the achromatic number of a tree is unknown. We present polynomial algorithms to solve this problem for several classes of trees, and provide upper bounds on the achromatic number of a tree in terms of the maximum degree and the number of edges.
43128338
Experiences with an architecture for intelligent, reactive agents
This paper describes an implementation of the 3T robot architecture which has been under development for the last eight years. The architecture uses three levels of abstraction and description languages which are compatible between levels. The makeup of the architecture helps to coordinate planful activities with real-time behaviours for dealing with dynamic environments. In recent years, other architectures have been created with similar attributes but two features distinguish the 3T architecture: (1) a variety of useful software tools have been created to help implement this architecture on multiple real robots; and (2) this architecture, or parts of it, have been implemented on a variety of very different robot systems using different processors, operating systems, effectors and sensor suites.
206839040
A Look at TPS
Certain aspects of the theorem proving system TPS are described. Type theory with λ-abstraction has been chosen as the logical language of TPS so that statements from many fields of mathematics and other disciplines can be expressed in terms accessible to the system.