1,739 research outputs found
On First-Order Definability and Computability of Progression for Local-Effect Actions and Beyond
No full textIn a seminal paper, Lin and Reiter introduced the
notion of progression for basic action theories in
the situation calculus. Unfortunately, progression is
not first-order definable in general. Recently, Vassos,
Lakemeyer, and Levesque showed that in case
actions have only local effects, progression is firstorder
representable. However, they could show
computability of the first-order representation only
for a restricted class. Also, their proofs were quite
involved. In this paper, we present a result stronger
than theirs that for local-effect actions, progression
is always first-order definable and computable. We
give a very simple proof for this via the concept
of forgetting. We also show first-order definability
and computability results for a class of knowledge
bases and actions with non-local effects. Moreover,
for a certain class of local-effect actions and
knowledge bases for representing disjunctive information,
we show that progression is not only firstorder
definable but also efficiently computable
Audiomobiles, Sculptures and Conundrums
No full textRoberto Gerhard was a pioneer of electronic music in England creating a number of substantial concert, theatre and radio works from as early as 1954. Gerhard’s electronic music is one of the richest repositories for understanding the development of the composer’s late compositional technique. Apart from the Symphony no.3, ‘Collages’, none of Gerhard’s electronic music is published. This paper will discuss aspects of Gerhard’s electronic music, focusing on Audiomobiles (1958-59) and Sculptures (1963)
Cognitive Robotics
No full textThis chapter is dedicated to the memory of Ray Reiter. It is also an overview of cognitive robotics, as we understand it to have been envisaged by him.1 Of course, nobody can control the use of a term or the direction of research. We apologize in advance to those who feel that other approaches to cognitive robotics and related problems are inadequately
represented here
First-Order Strong Progression for Local-Effect Basic Action Theories
No full textIn a seminal paper Lin and Reiter introduced the notion of progression for basic action theories in the situation calculus. The idea is to replace an initial database by a new set of sentences which reflect the changes due to an action. Unfortunately, progression requires secondorder logic in general. In this paper, we introduce the notion of strong progression, a slight variant of Lin and Reiter that has the intended properties, and we show that in case actions have only local effects, progression is always first-order representable. Moreover, for a restricted class of local-effect axioms we show how to construct a new database that is finite
Self-Maintenance for Autonomous Robots in the Situation Calculus
No full textIn order to make a robot execute a given task plan more
robustly we want to enable it to take care of its self-maintenance requirements
during online execution of this program. This requires the
robot to know about the (internal) states of its components, constraints
that restrict execution of certain actions and possibly also how to recover
from faulty situations. The general idea is to implement a transformation
process on the plans, which are specified in the agent programming
language ReadyLog, to be performed based on explicit (temporal) constraints.
Afterwards, a ’guarded’ execution of the transformed program
should result in more robust behavior
10081 Abstracts Collection – Cognitive Robotics
No full textFrom 21.02. to 26.02.2010, the Dagstuhl Seminar 10081 ``Cognitive Robotics '' was held in Schloss Dagstuhl~--~Leibniz Center for Informatics.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
Towards an Axiom System for Default Logic
No full textRecently, Lakemeyer and Levesque proposed a logic of onlyknowing which precisely captures three forms of nonmonotonic reasoning: Moore’s Autoepistemic Logic, Konolige’s variant based on moderately grounded expansions, and Reiter’s default logic. Defaults have a uniform representation under all three interpretations in the new logic. Moreover, the logic itself is monotonic, that is, nonmonotonic reasoning is cast in terms of validity in the classical sense. While Lakemeyer and Levesque gave a model-theoretic account of their logic, a proof-theoretic characterization remained open. This paper fills that gap for the propositional subset: a sound and complete axiom system in the new logic for all three varieties of default reasoning. We also present formal derivations for some examples of default reasoning. Finally we present evidence that it is unlikely that a complete axiom system exists in the first-order case, even when restricted to the simplest forms of default reasoning
Cognitive Robotics (Dagstuhl Seminar 22391)
No full textThis report documents the program and the outcomes of Dagstuhl Seminar 22391 on the topic of "Cognitive Robotics". Cognitive Robotics is concerned with endowing robots or software agents with higher level cognitive functions that involve reasoning, for example, about goals, perception, actions, the mental states of other agents, and collaborative task execution. The seminar is the latest event in a series of events on this topic that were initiated in 1998. With its roots in knowledge representation and reasoning, the program for this seminar was influenced by transformative advances in machine learning and deep learning, by recent advances in human-robot interactions, and by issues that arise in the development of trustworthy cognitive robotic systems. Reflective of this, the seminar featured sessions devoted to the following four themes: cognitive robotics and KR, verification of cognitive robots, human-robot interaction and robot ethics, and planning and learning. Each theme consisted of plenary talks, plenary discussions and working groups resulting in a research road map for the coming years. There was also a poster session where new or published results could be presented by the participants.
The seminar was very successful and well received by the participants thanks to the excellent environment for exchanging ideas provided by Schloss Dagstuhl
Query Evaluation and Progression in AOL Knowledge Bases
No full textRecently Lakemeyer and Levesque proposed the logic AOL, which amalgamates both the situation calculus and Levesque's logic of only knowing. While ver
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