In fact, goal-driven hierarchical structure to concatenate simple human behavior is mostly constituted by goal-directed motor acts. This hierarchical goal structure as well as the actions based on the synergic composition of simpler rules, which connect individual motor elements, might be motor constituents chained together according to a precise paralleled to the syntactic organization of language.

The paper addresses the following issues:  (a) how to represent semantic information from natural language so that a vision model can utilize it?  (b) how to extract the salient textual information relevant to vision?  For a given domain, we present a new model of semantic extraction that takes into account word relatedness as well as word disambiguation in order to apply to a vision model. We automatically process the text transcripts and perform syntactic analysis to extract dependency relations. We then perform semantic extraction on the output to filter semantic entities related to actions. The resulting data are used to populate a matrix of co-occurrences utilized by the vision processing modules.  Results show that explicitly modeling the co-occurrence of actions and tools significantly improved performance.

We develop a Bayesian approach to concept learning for crowdsourcing applications. A probabilistic belief over possible concept definitions is maintained and updated according to (noisy) observations from experts, whose behaviors are modeled using discrete types. We propose recommendation techniques, inference methods, and query selection strategies to assist a user charged with choosing a configuration that satisfies some (partially known) concept. Our model is able to simultaneously learn the concept definition and the types of the experts. We evaluate our model with simulations, showing that our Bayesian strategies are effective even in large concept spaces with many uninformative experts.

This article studies Frequency Adjusted Q-learning (FAQ-learning), a variation of Q-learning that simulates simultaneous value function updates. The main contributions are empirical and theoretical support for the convergence of FAQ-learning to attractors near Nash equilibria in two-agent two-action matrix games.The games can be divided into three types: Matching pennies, Prisoners' Dilemma and Battle of Sexes. This article shows that the Matching pennies and Prisoners' Dilemma yield one attractor of the learning dynamics, while the Battle of Sexes exhibits a supercritical pitchfork bifurcation at a critical temperature, where one attractor splits into two attractors and one repellent fixed point. Experiments illustrate that the distance between fixed points of the FAQ-learning dynamics and Nash equilibria tends to zero as the exploration parameter of FAQ-learning approaches zero.

Learning about users' preferences allows agents to make intelligent decisions on behalf of users. When we are eliciting preferences from a group of users, we can use the preferences of the users we have already processed to increase the efficiency of the elicitation process for the remaining users. However, current methods either require strong prior knowledge about the users' preferences or can be overly cautious and inefficient. Our method, based on standard techniques from non-parametric statistics, allows the controller to choose a balance between prior knowledge and efficiency. This balance is investigated through experimental results.

Results from behavioral economics show that individuals do not always maximize monetary payoffs. Within behavioral economics different models of social preference have been put forth to account for this deviation from standard assumptions of game theory and economics. Incorporating such models into agent decision making is increasingly relevant to design systems which interact with or on behalf of humans. Existing models, which correctly predict outcomes across a large set of games, are fairly complex. To this end, we present aspiration based social preference model and evaluate it by considering two player dilemma games. We show that the qualitative predictions of our model are consistent with results from behavioral economics.

The growing use of autonomous agents in practice may require agents to cooperate as a team in situations where they have limited prior knowledge about one another, cannot communicate directly, or do not share the same world models. These situations raise the need to design ad hoc team members, i.e., agents that will be able to cooperate without coordination in order to reach an optimal team behavior. This paper considers problem of leading N-agent teams by a single agent toward their optimal joint utility, where the agents compute their next actions based only on their most recent observations of their teammates' actions. We show that compared to previous results in two-agent teams, in larger teams the agent might not be able to lead the team to the action with maximal joint utility. In these cases, the agent's optimal strategy leads the team to the best possible reachable cycle of joint actions. We describe a graphical model of the problem and a polynomial time algorithm for solving it. We then consider the problem of leading teams where the agents' base their actions on a longer history of past observations, showing that the an upper bound computation time exponential in the memory size is very likely to be tight.

This extended abstract outlines a new study that investigates spatial language for use in human-robot communication. The scenario studied is a home setting in which the elderly resident has misplaced an object, such as eyeglasses, and the robot will help the resident find the object. We present preliminary results from the initial study in which we investigate spatial language generated to a human addressee or a robot addressee in a virtual environment.

Robot factors such as motions and utterances have a possibility of interaction effects with generation and other human factors, and these effects influence robotics design in elder care. Some psychological experiments conducted in our research group found these interaction effects between generation and other factors based on directly comparison between younger and elder persons in interaction with a small-sized humanoid robot. The paper firstly reviews the previous two studies, reports results of the current experiment, and then discusses about their implications from the perspective of robotics design for elder care.

This paper examines the ability of the Paro robot to improve the lives of elderly dementia patients by applying modern technology to medicine. Paro is not intended to be a replacement for social interaction with people or animals. Some patients who know Paro is a robot still enjoy using the robotic seal, and it can calm patients who are otherwise unreachable. Robots like Paro which mimic the behaviors of pets offer excellent opportunities to connect with challenging patients; however they raise concerns regarding patient rights and autonomy. While such concerns are worthy of consideration, which we discuss in this paper, we nonetheless conclude that the benefits of using such a treatment tool outweigh its potential risks.