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Expressiveness of Two-Valued Semantics for Abstract Dialectical Frameworks

Journal of Artificial Intelligence Research

By expressiveness we mean the ability to encode a desired set of two-valued interpretations over a given propositional vocabulary A using only atoms from A. We also compare ADFs' expressiveness with that of (the two-valued semantics of) abstract argumentation frameworks, normal logic programs and propositional logic. While the computational complexity of the two-valued model existence problem for all these languages is (almost) the same, we show that the languages form a neat hierarchy with respect to their expressiveness. We then demonstrate that this hierarchy collapses once we allow to introduce a linear number of new vocabulary elements. We finally also analyse and compare the representational succinctness of ADFs (for two-valued model semantics), that is, their capability to represent two-valued interpretation sets in a space-efficient manner.


Metaphysics of Planning Domain Descriptions

AAAI Conferences

Domain models for sequential decision making typically represent abstract versions of real-world systems. In practice, such representations are compact, easy to maintain, and affort faster solution times. Unfortunately, as we show in this paper, simple ways of abstracting solvable real-world problems may lead to models whose solutions are incorrect with respect to the real-world problem. There is some evidence that such limitations have restricted the applicability of SDM technology in the real world, as is apparent in the case of task and motion planning in robotics. We show that the situation can be ameliorated by a combination of increased expressive power---for example, allowing angelic nondeterminism in action effects---and new kinds of algorithmic approaches designed to produce correct solutions from initially incorrect or non-Markovian abstract models.


Position Paper: Knowledge-Based Mechanisms for Deception

AAAI Conferences

In an earlier paper, I described in some detail how a system based on symbolic knowledge representation and reasoning could model and reason about an act of deception encountered in a children's story. This short position paper extends that earlier work, adding new analysis and discussion about the nature of deception, the desirability of building deceptive AI systems, and the computational mechanisms necessary for deceiving others and for recognizing their attempts to deceive us.


Represent and Infer Human Theory of Mind for Human-Robot Interaction

AAAI Conferences

This abstract is proposing a challenging problem: to infer a human's mental state — intent and belief — from an observed RGBD video for human-robot interaction. The task is to integrate symbolic reasoning, a field well-studied within A.I. domains, with the uncertainty native to computer vision strategies. Traditional A.I. strategies for plan inference typically rely on first-order logic and closed world assumptions which struggle to take into account the inherent uncertainty of noisy observations within a scene. Computer vision relies on pattern-recognition strategies that have difficulty accounting for higher-level reasoning and abstract representation of world knowledge. By combining these two approaches in a principled way under a probabilistic programming framework, we define new computer vision tasks such as actor intent prediction and belief inference from an observed video sequence. Through inferring a human's theory of mind, a robotic agent can automatically determine a human's goals to collaborate with them.


“Sorry, I Can’t Do That”: Developing Mechanisms to Appropriately Reject Directives in Human-Robot Interactions

AAAI Conferences

An ongoing goal at the intersection of artificial intelligence In this paper, we briefly present initial work that has (AI), robotics, and human-robot interaction (HRI) is to create been done in the DIARC/ADE cognitive robotic architecture autonomous agents that can assist and interact with human (Schermerhorn et al. 2006; Kramer and Scheutz 2006) to enable teammates in natural and humanlike ways. This is a such a rejection and explanation mechanism. First we multifaceted challenge, involving both the development of discuss the theoretical considerations behind this challenge, an ever-expanding set of capabilities (both physical and algorithmic) specifically the conditions that must be met for a directive to such that robotic agents can autonomously engage be appropriately accepted. Next, we briefly present some of in a variety of useful tasks, as well as the development the explicit reasoning mechanisms developed in order to facilitate of interaction mechanisms (e.g.


A Tripartite Plan-Based Model of Narrative for Narrative Discourse Generation

AAAI Conferences

The story is particular medium. However, the discourse layer is not simply a conceptualization of the world of the narrative, with the an ordered subset of elements of the story layer. Genette characters, actions and events that it contains, while the discourse argues that every discourse implies a narrator. In this, the is composed of the communicative elements that participate discourse is an intentional structure through which the narrator in its telling. Research on computational models of "regulates the narrative information" given to the audience, narrative has produced many models of story, based for instance and its representation should include these intentions.


MKULTRA (Demo)

AAAI Conferences

MKULTRA is an experimental game that explores novel AI-based game mechanics. Similar in some ways to text-based interactive fiction, the player controls a character who interacts with other characters through dialog.  Unlike traditional IF, MKULTRA characters have simple natural language understanding and generation capabilities, sufficient to answer questions and carry out simple tasks.  The game explores a novel game mechanic, belief injection, in which players can manipulate the behavior of NPCs by injecting false beliefs into their knowledge bases.  This allows for an unusual form of puzzle-based gameplay, in which the player must understand the beliefs and motivational structure of the characters well enough to understand what beliefs to inject.


Reports on the 2015 AAAI Spring Symposium Series

AI Magazine

The AAAI 2015 Spring Symposium Series was held Monday through Wednesday, March 23-25, at Stanford University near Palo Alto, California. The titles of the seven symposia were Ambient Intelligence for Health and Cognitive Enhancement, Applied Computational Game Theory, Foundations of Autonomy and Its (Cyber) Threats: From Individuals to Interdependence, Knowledge Representation and Reasoning: Integrating Symbolic and Neural Approaches, Logical Formalizations of Commonsense Reasoning, Socio-Technical Behavior Mining: From Data to Decisions, Structured Data for Humanitarian Technologies: Perfect Fit or Overkill?


Reports on the 2015 AAAI Spring Symposium Series

AI Magazine

The AAAI 2015 Spring Symposium Series was held Monday through Wednesday, March 23-25, at Stanford University near Palo Alto, California. The titles of the seven symposia were Ambient Intelligence for Health and Cognitive Enhancement, Applied Computational Game Theory, Foundations of Autonomy and Its (Cyber) Threats: From Individuals to Interdependence, Knowledge Representation and Reasoning: Integrating Symbolic and Neural Approaches, Logical Formalizations of Commonsense Reasoning, Socio-Technical Behavior Mining: From Data to Decisions, Structured Data for Humanitarian Technologies: Perfect Fit or Overkill? and Turn-Taking and Coordination in Human-Machine Interaction.The highlights of each symposium are presented in this report.


An End-to-End Conversational Second Screen Application for TV Program Discovery

AI Magazine

In this article, we report on a multiphase R&D effort to develop a conversational second screen application for TV program discovery. Our goal is to share with the community the breadth of artificial intelligence (AI) and natural language (NL) technologies required to develop such an application along with learnings from target end-users. We first give an overview of our application from the perspective of the end-user. We then present the architecture of our application along with the main AI and NL components, which were developed over multiple phases. The first phase focuses on enabling core functionality such as effectively finding programs matching the user’s intent. The second phase focuses on enabling dialog with the user. Finally, we present two user studies, corresponding to these two phases. The results from both studies demonstrate the effectiveness of our application in the target domain.