205124426
Computing Grasp Functions
Abstract The grasp function of a planar part, characterized by extrema in the part's width function, can be used to analyze grasp mechanics. In particular, it can predict the final orientation of the part when it is grasped with a parallel-jaw gripper. This information allows us to derive a sequence of grasp angles that will orient the part up to symmetry in the grasp function. In previous papers the grasp function was assumed given as input; in this paper we present a linear-time algorithm for computing the grasp function of a part bounded by n algebraic arcs given in parametric form. We also show that the algorithm can be extended to compute a related function that describes the outcome of first pushing and then grasping the part.
694579
Placing registration marks
The registration mark problem is defined, as follows. Given an n-sided rigid planar polygonal part and a set of k planar geometric transforms, locate a point on the surface of the part that maximizes the minimum distance between transformed points. A registration mark at this point will be maximally robust to sensor imperfections. An O(n log/sup 2/k+k/sup 4/ log k log*k) time algorithm for solving this planar problem is given, and the result is demonstrated using the Image-Calc vision system. The results extend to curved planar parts and polyhedral parts. How part shape can be redesigned to simplify localization is considered. In essence, it is shown how to design the surface of a part to facilitate automated assembly.<<ETX>>
38878591
Social and Individual Commitment
Agents interacting in team environments make use of a social structure which, Castelfranchi has recently claimed, must be modelled by commitments which are external to any particular agent. Such social commitments are between agents, though usually with respect to some action or state which the committed agent is prepared to perform or achieve. We start with Castelfranchi's concept of social commitment and formalise aspects of it within the BDI agent framework. We use this formalisation to characterise different sorts of social behaviour in the interaction between agents.
9505205
Mixed Mode XML Query Processing
Querying XML documents typically involves both tree-based navigation and pattern matching similar to that used in structured information retrieval domains. In this paper, we show that for good performance, a native XML query processing system should support query plans that mix these two processing paradigms. We describe our prototype native XML system, and report on experiments demonstrating that even for simple queries, there are a number of options for how to combine tree-based navigation and structural joins based on information retrieval-style inverted lists, and that these options can have widely varying performance. We present ways of transparently using both techniques in a single system, and provide a cost model for identifying efficient combinations of the techniques. Our preliminary experimental results prove the viability of our approach.
205493040
Probabilities of therapeutic extinction of HIV
Using branching process principles and recent developments in HIV immunology, a methodology is demonstrated to compute the probability of extinction of HIV in the presence of protease inhibitors.
27820977
A Monotonic Formalism for Events and Systems of Events
The aim of this paper is to provide a basis for a theory of events and systems of events that can be used for reasoning about arbitrarily complex dynamic domains involving multiple agents. The approach is based on a model of events that explicitly represents the domain of influence of each event By restricting the scope of an event's domain of influence, most of the problems that have seriously troubled the more conventional state-transition models of events can be avoided. The effect of performing events, either in isolation or in parallel with other events, is described. A formalism is developed that allows reasoning about arbitrarily complex behaviours. It is shown how this formalism avoids the frame problem yet allows the ramifications of any given event occurrence to be modelled without the introduction of non-monotonic mechanisms. Finally, the notion of system is introduced to provide a compositional means for reasoning about complex
11388485
The number of reachable pairs in a digraph
For a digraph G, let R(G) (respectively, R^(^k^)(G)) be the number of ordered pairs (u,v) of vertices of G such that u v and v is reachable from u (respectively, reachable from u by a path of length ==k+(k+1)^0^.^5^7+2, for arbitrary k.