Education
Online Learning and Profit Maximization from Revealed Preferences
Amin, Kareem (University of Pennsylvania) | Cummings, Rachel (California Institute of Technology) | Dworkin, Lili (University of Pennsylvania) | Kearns, Michael (University of Pennsylvania) | Roth, Aaron (University of Pennsylvania)
We consider the problem of learning from revealed preferences in an online setting. In our framework, each period a consumer buys an optimal bundle of goods from a merchant according to her (linear) utility function and current prices, subject to a budget constraint. The merchant observes only the purchased goods, and seeks to adapt prices to optimize his profits. We give an efficient algorithm for the merchant's problem that consists of a learning phase in which the consumer's utility function is (perhaps partially) inferred, followed by a price optimization step. We also give an alternative online learning algorithm for the setting where prices are set exogenously, but the merchant would still like to predict the bundle that will be bought by the consumer, for purposes of inventory or supply chain management. In contrast with most prior work on the revealed preferences problem, we demonstrate that by making stronger assumptions on the form of utility functions, efficient algorithms for both learning and profit maximization are possible, even in adaptive, online settings.
Ontology-Based Information Extraction with a Cognitive Agent
Lindes, Peter (Brigham Young University) | Lonsdale, Deryle W. (Brigham Young University) | Embley, David W. (Brigham Young University)
Machine reading is a relatively new field that features computer programs designed to read flowing text and extract fact assertions expressed by the narrative content. This task involves two core technologies: natural language processing (NLP) and information extraction (IE). In this paper we describe a machine reading system that we have developed within a cognitive architecture. We show how we have integrated into the framework several levels of knowledge for a particular domain, ideas from cognitive semantics and construction grammar, plus tools from prior NLP and IE research. The result is a system that is capable of reading and interpreting complex and fairly idiosyncratic texts in the family history domain. We describe the architecture and performance of the system. After presenting the results from several evaluations that we have carried out, we summarize possible future directions.
Bayesian Affect Control Theory of Self
Hoey, Jesse (University of Waterloo) | Schroeder, Tobias (Potsdam University of Applied Sciences)
Notions of identity and of the self have long been studied in social psychology and sociology as key guiding elements of social interaction and coordination. In the AI of the future, these notions will also play a role in producing natural, socially appropriate artificially intelligent agents that encompass subtle and complex human social and affective skills. We propose here a Bayesian generalization of the sociological affect control theory of self as a theoretical foundation for socio-affectively skilled artificial agents. This theory posits that each human maintains an internal model of his or her deep sense of "self" that captures their emotional, psychological, and socio-cultural sense of being in the world. The "self" is then externalised as an identity within any given interpersonal and institutional situation, and this situational identity is the person's local (in space and time) representation of the self. Situational identities govern the actions of humans according to affect control theory. Humans will seek situations that allow them to enact identities consistent with their sense of self. This consistency is cumulative over time: if some parts of a person's self are not actualized regularly, the person will have a growing feeling of inauthenticity that they will seek to resolve. In our present generalisation, the self is represented as a probability distribution, allowing it to be multi-modal (a person can maintain multiple different identities), uncertain (a person can be unsure about who they really are), and learnable (agents can learn the identities and selves of other agents). We show how the Bayesian affect control theory of self can underpin artificial agents that are socially intelligent.
A Hebbian/Anti-Hebbian Neural Network for Linear Subspace Learning: A Derivation from Multidimensional Scaling of Streaming Data
Pehlevan, Cengiz, Hu, Tao, Chklovskii, Dmitri B.
Neural network models of early sensory processing typically reduce the dimensionality of streaming input data. Such networks learn the principal subspace, in the sense of principal component analysis (PCA), by adjusting synaptic weights according to activity-dependent learning rules. When derived from a principled cost function these rules are nonlocal and hence biologically implausible. At the same time, biologically plausible local rules have been postulated rather than derived from a principled cost function. Here, to bridge this gap, we derive a biologically plausible network for subspace learning on streaming data by minimizing a principled cost function. In a departure from previous work, where cost was quantified by the representation, or reconstruction, error, we adopt a multidimensional scaling (MDS) cost function for streaming data. The resulting algorithm relies only on biologically plausible Hebbian and anti-Hebbian local learning rules. In a stochastic setting, synaptic weights converge to a stationary state which projects the input data onto the principal subspace. If the data are generated by a nonstationary distribution, the network can track the principal subspace. Thus, our result makes a step towards an algorithmic theory of neural computation.
Teaching AI Ethics Using Science Fiction
Burton, Emanuelle (Center College) | Goldsmith, Judy (University of Kentucky) | Mattei, Nicholas (NICTA and University of New South Wales)
The cultural and political implications of modern AI research are not some far off concern, they are things that affect the world in the here and now. From advanced control systems with advanced visualizations and image processing techniques that drive the machines of the modern military to the slow creep of a mechanized workforce, ethical questions surround us. Part of dealing with these ethical questions is not just speculating on what could be but teaching our students how to engage with these ethical questions. We explore the use of science fiction as an appropriate tool to enable AI researchers to help engage students and the public on the current state and potential impacts of AI.
Modeling Spatial-Temporal Dynamics of Human Movements for Predicting Future Trajectories
Wang, Zhan (KTH Royal Institute of Technology) | Jensfelt, Patric (KTH Royal Institute of Technology) | Folkesson, John (KTH Royal Institute of Technology)
This paper presents a novel approach to modeling the dynamics of human movements with a grid-based representation.For each grid cell, we formulate the local dynamics using a variant of the left-to-right HMM, and thus explicitly model the exiting direction from the current cell. The dependency of this process on the entry direction is captured by employing the Input-Output HMM (IOHMM). On a higher level, we introduce the place where the whole trajectory originated into the IOHMM framework forming a hierarchical input structure. Therefore, we manage to capture both local spatial-temporal correlations and the long-term dependency on faraway initiating events, thus enabling the developed model to incorporate more information and to generate more informative predictions of future trajectories.The experimental results in an office corridor environment verify the capabilities of our method.
Interactive Multi-Consumer Power Cooperatives with Learning and Axiomatic Cost and Risk Disaggregation
Ehsanfar, Abbas (Stevens Institute of Technology) | Heydari, Babak (Stevens Institute of Technology)
This paper introduces a novel autonomous interactive learning cooperative (ILCP) who receives expected value and variance of load from consumers and participates in the electricity market on their behalf. Using an axiomatic approach, the share of each consumer's payment as well as its weight in calculating the modification of total day-ahead load are formulated. This scheme applies double-seasonal smoothing exponential, a recent load forecasting technique, and a classifier for real-time to day-ahead price direction forecasting (Gaussian Naïve Bayes). In addition to this, the ILCP employs interactive cooperative algorithms for both trading cooperative and consumer side. The ILCP scheme is investigated and its performance is compared to those of non-cooperative real-time pricing (RTP), LCP (non-interactive learning cooperative) and CP (non-interactive non-learning cooperative). The developed system was implemented using PJM(world's largest wholesale electricity market) real-time and day-ahead data for 2013 and half of 2014; real load profiles were selected from a set of 579 residential and commercial consumers, and weather data were applied to forecasting electricity price direction. We demonstrate the advantages of ILCP to lower the average electricity cost and to reduce unit price variations.
What Women Want: Analyzing Research Publications to Understand Gender Preferences in Computer Science
Mihalcea, Rada (University of Michigan) | Welch, Charles (University of Michigan)
While the number of women who choose to pursue computer science and engineering careers is growing, men continue to largely outnumber them. In this paper, we describe a data mining approach that relies on a large collection of scientific articles to identify differences in gender interests in this field. Our hope is that through a better understanding of the differences between male and female preferences, we can enable more effective outreach and retention, and consequently contribute to the growth of the number of women who choose to pursue careers in this field.
Nonparametric Bayesian Learning of Other Agents' Policies in Interactive POMDPs
Panella, Alessandro (University of Illinois at Chicago) | Gmytrasiewicz, Piotr (University of Illinois at Chicago)
We consider an autonomous agent facing a partially observable, stochastic, multiagent environment where the unknown policies of other agents are represented as finite state controllers (FSCs). We show how an agent can (i) learn the FSCs of the other agents, and (ii) exploit these models during interactions. To separate the issues of off-line versus on-line learning we consider here an off-line two-phase approach. During the first phase the agent observes as the other player(s) are interacting with the environment (the observations may be imperfect and the learning agent is not taking part in the interaction.) The collected data is used to learn an ensemble of FSCs that explain the behavior of the other agent(s) using a Bayesian non-parametric (BNP) approach. We verify the quality of the learned models during the second phase by allowing the agent to compute its own optimal policy and interact with the observed agent. The optimal policy for the learning agent is obtained by solving an interactive POMDP in which the states are augmented by the other agent(s)' possible FSCs. The advantage of using the Bayesian nonparametric approach in the first phase is that the complexity (number of nodes) of the learned controllers is not bounded a priori. Our two-phase approach is preliminary and separates the learning using BNP from the complexities of learning on-line while the other agent may be modifying its policy (on-line approach is subject of our future work.) We describe our implementation and results in a multiagent Tiger domain. Our results show that learning improves the agent's performance, which increases with the amount of data collected during the learning phase.
I Spy: An Interactive Game-Based Approach to Multimodal Robot Learning
Parde, Natalie Paige (University of North Texas) | Papakostas, Michalis (University of Texas Arlington and NCSR Demokritos) | Tsiakas, Konstantinos (University of Texas Arlington and NCSR Demokritos) | Dagioglou, Maria (NCSR Demokritos) | Karkaletsis, Vangelis (NCSR Demokritos) | Nielsen, Rodney D (University of North Texas)
Teaching robots about objects in their environment requires a multimodal correlation of images and linguistic descriptions to build complete feature and object models. These models can be created manually by collecting images and related keywords and presenting the pairings to robots, but doing so is tedious and unnatural. This work abstracts the problem of training robots to learn about the world around them by introducing I Spy , an interactive dialogue- and vision-based game in which players place objects in front of a humanoid robot and challenge it to guess which object they have in mind. The robot gradually learns about the objects and the features which describe them through repeated games, by updating its knowledge with newly captured training images. This paper details I Spy's learning and gaming processes, describes the approaches taken to extract information from multiple modalities both before and during gameplay, and finally discusses the results of a study designed to evaluate the game's model accuracy over time, its overall performance, and its appeal to human players.