Goto

Collaborating Authors

 Agent Societies


Reports of the AAAI 2017 Fall Symposium Series

AI Magazine

The AAAI 2017 Fall Symposium Series was held Thursday through Saturday, November 9โ€“11, at the Westin Arlington Gateway in Arlington, Virginia, adjacent to Washington, DC. The titles of the six symposia were Artificial Intelligence for Human-Robot Interaction; Cognitive Assistance in Government and Public Sector Applications; Deep Models and Artificial Intelligence for Military Applications: Potentials, Theories, Practices, Tools and Risks; Human-Agent Groups: Studies, Algorithms and Challenges; Natural Communication for Human-Robot Collaboration; and A Standard Model of the Mind. The highlights of each symposium (except the Natural Communication for Human-Robot Collaboration symposium, whose organizers did not submit a report) are presented in this report.


Incentive-Compatible Mechanisms for Norm Monitoring in Open Multi-Agent Systems

Journal of Artificial Intelligence Research

We consider the problem of detecting norm violations in open multi-agent systems (MAS). We show how, using ideas from scrip systems, we can design mechanisms where the agents comprising the MAS are incentivised to monitor the actions of other agents for norm violations. The cost of providing the incentives is not borne by the MAS and does not come from fines charged for norm violations (fines may be impossible to levy in a system where agents are free to leave and rejoin again under a different identity). Instead, monitoring incentives come from (scrip) fees for accessing the services provided by the MAS. In some cases, perfect monitoring (and hence enforcement) can be achieved: no norms will be violated in equilibrium. In other cases, we show that, while it is impossible to achieve perfect enforcement, we can get arbitrarily close; we can make the probability of a norm violation in equilibrium arbitrarily small. We show using simulations that our theoretical results, which apply to systems with a large number of agents, hold for multi-agent systems with as few as 1000 agents--the system rapidly converges to the steady-state distribution of scrip tokens necessary to ensure monitoring and then remains close to the steady state.


Who will win the AI race? If countries work together, then the answer could be all of us

#artificialintelligence

With global cooperation, we can effectively take on the truth we all acknowledge: perhaps more than previous technological breakthroughs in human history, AI brings challenges along with its enormous potential for good. Yet based on our conversations with government officials, academics, entrepreneurs, journalists and other stakeholders over the past year or two, we at Malong Technologies are unabashedly hopeful. We see a broadening consensus and a willingness to address issues together with a sense of shared responsibility. We see people from all walks of life giving serious thought to the roles they can play and the contributions they can make.


Solving Multi-agent Path Finding on Strongly Biconnected Digraphs

Journal of Artificial Intelligence Research

Much of the literature on suboptimal, polynomial-time algorithms for multi-agent path finding focuses on undirected graphs, where motion is permitted in both directions along a graph edge. Despite this, traveling on directed graphs is relevant in navigation domains, such as path finding in games, and asymmetric communication networks.We consider multi-agent path finding on strongly biconnected directed graphs. We show that all instances with at least two unoccupied positions have a solution, except for a particular, degenerate subclass where the graph has a cyclic shape. We present diBOX, an algorithm for multi-agent path finding on strongly biconnected directed graphs. diBOX runs in polynomial time, computes suboptimal solutions and is complete for instances on strongly biconnected digraphs with at least two unoccupied positions. We theoretically analyze properties of the algorithm and properties of strongly biconnected directed graphs that are relevant to our approach. We perform a detailed empirical analysis of diBOX, showing a good scalability. To our knowledge, our work is the first study of multi-agent path finding focused on directed graphs.


Rosenstein Calls for Global Collaboration on Crime Amid Trade Tension

U.S. News

Rosenstein said during a speech in Montreal the United States is "enhancing its commitment to international law enforcement coordination," through personal relationships, policy changes and additional resources, citing examples of recent collaboration between Canadian and U.S. law enforcement.


Multi-Agent Path Finding with Deadlines

arXiv.org Artificial Intelligence

We formalize Multi-Agent Path Finding with Deadlines (MAPF-DL). The objective is to maximize the number of agents that can reach their given goal vertices from their given start vertices within the deadline, without colliding with each other. We first show that MAPF-DL is NP-hard to solve optimally. We then present two classes of optimal algorithms, one based on a reduction of MAPF-DL to a flow problem and a subsequent compact integer linear programming formulation of the resulting reduced abstracted multi-commodity flow network and the other one based on novel combinatorial search algorithms. Our empirical results demonstrate that these MAPF-DL solvers scale well and each one dominates the other ones in different scenarios.


Shallow decision-making analysis in General Video Game Playing

arXiv.org Artificial Intelligence

The General Video Game AI competitions have been the testing ground for several techniques for game playing, such as evolutionary computation techniques, tree search algorithms, hyper heuristic based or knowledge based algorithms. So far the metrics used to evaluate the performance of agents have been win ratio, game score and length of games. In this paper we provide a wider set of metrics and a comparison method for evaluating and comparing agents. The metrics and the comparison method give shallow introspection into the agent's decision making process and they can be applied to any agent regardless of its algorithmic nature. In this work, the metrics and the comparison method are used to measure the impact of the terms that compose a tree policy of an MCTS based agent, comparing with several baseline agents. The results clearly show how promising such general approach is and how it can be useful to understand the behaviour of an AI agent, in particular, how the comparison with baseline agents can help understanding the shape of the agent decision landscape. The presented metrics and comparison method represent a step toward to more descriptive ways of logging and analysing agent's behaviours.


A COP Model For Graph-Constrained Coalition Formation

Journal of Artificial Intelligence Research

We consider Graph-Constrained Coalition Formation (GCCF), a widely studied subproblem of coalition formation in which the set of valid coalitions is restricted by a graph. We propose COP-GCCF, a novel approach that models GCCF as a COP, and we solve such COP with a highly-parallel approach based on Bucket Elimination executed on the GPU, which is able to exploit the high constraint tightness of COP-GCCF. Results show that our approach outperforms state of the art algorithms (i.e., DyCE and IDPG) by at least one order of magnitude on realistic graphs, i.e., a crawl of the Twitter social graph, both in terms of runtime and memory.


On the Computational Complexity of Model Checking for Dynamic Epistemic Logic with S5 Models

arXiv.org Artificial Intelligence

Dynamic epistemic logic (DEL) is a logical framework for representing and reasoning about knowledge change for multiple agents. An important computational task in this framework is the model checking problem, which has been shown to be PSPACE-hard even for S5 models and two agents. We answer open questions in the literature about the complexity of this problem in more restricted settings. We provide a detailed complexity analysis of the model checking problem for DEL, where we consider various combinations of restrictions, such as the number of agents, whether the models are single-pointed or multi-pointed, and whether postconditions are allowed in the updates. In particular, we show that the problem is already PSPACE-hard in (1) the case of one agent, multi-pointed S5 models, and no postconditions, and (2) the case of two agents, only single-pointed S5 models, and no postconditions. In addition, we study the setting where only semi-private announcements are allowed as updates. We show that for this case the problem is already PSPACE-hard when restricted to two agents and three propositional variables.


Learning Attentional Communication for Multi-Agent Cooperation

arXiv.org Artificial Intelligence

Communication could potentially be an effective way for multi-agent cooperation. However, information sharing among all agents or in predefined communication architectures that existing methods adopt can be problematic. When there is a large number of agents, agents hardly differentiate valuable information that helps cooperative decision making from globally shared information. Therefore, communication barely helps, and could even impair the learning of multi-agent cooperation. Predefined communication architectures, on the other hand, restrict communication among agents and thus restrain potential cooperation. To tackle these difficulties, in this paper, we propose an attentional communication model that learns when communication is needed and how to integrates shared information for cooperative decision making. Our model leads to efficient and effective communication for large-scale multi-agent cooperation. Empirically, we show the strength of our model in various cooperative scenarios, where agents are able to develop more coordinated and sophisticated strategies than existing methods.