Industry
AIIDE 2013 StarCraft Competition
Buro, Michael (University of Alberta, Edmonton) | Churchill, David (University of Alberta, Edmonton)
In 2013, AIIDE will host the Fourth Annual Star-Craft AI Competition. Participants are given the task of building the best performing AI system for the popular real-time strategy game StarCraft Brood War (Blizzard Entertainment). Thee goals of the competition are to provide a testbed for real-time AI systems and to promote game AI research by exhibiting AI techniques such as scripting, planning, optimization, spatial reasoning, and opponent modeling in a fast-paced popular video game.
Preface
Sukthankar, Gita (University of Central Florida ) | Horswill, Ian (Northwestern University)
The computer game industry has become a multibillion-dollar commercial enterprise, comparable in size and scope to the film industry. Game system requirements are an important driver of hardware and soware innovation in the computer industry, and games have expanded to fill market niches opened by new platforms such as mobile phones, consoles, tablets, and social media. Artificial intelligence is a major component contributing to this success, creating the conditions for more complex virtual environments, realistic non-player characters, and engaging experiences.
Learning Gaussian Graphical Models with Observed or Latent FVSs
Gaussian Graphical Models (GGMs) or Gauss Markov random fields are widely used in many applications, and the trade-off between the modeling capacity and the efficiency of learning and inference has been an important research problem. In this paper, we study the family of GGMs with small feedback vertex sets (FVSs), where an FVS is a set of nodes whose removal breaks all the cycles. Exact inference such as computing the marginal distributions and the partition function has complexity $O(k^{2}n)$ using message-passing algorithms, where k is the size of the FVS, and n is the total number of nodes. We propose efficient structure learning algorithms for two cases: 1) All nodes are observed, which is useful in modeling social or flight networks where the FVS nodes often correspond to a small number of high-degree nodes, or hubs, while the rest of the networks is modeled by a tree. Regardless of the maximum degree, without knowing the full graph structure, we can exactly compute the maximum likelihood estimate in $O(kn^2+n^2\log n)$ if the FVS is known or in polynomial time if the FVS is unknown but has bounded size. 2) The FVS nodes are latent variables, where structure learning is equivalent to decomposing a inverse covariance matrix (exactly or approximately) into the sum of a tree-structured matrix and a low-rank matrix. By incorporating efficient inference into the learning steps, we can obtain a learning algorithm using alternating low-rank correction with complexity $O(kn^{2}+n^{2}\log n)$ per iteration. We also perform experiments using both synthetic data as well as real data of flight delays to demonstrate the modeling capacity with FVSs of various sizes.
Pattern-Coupled Sparse Bayesian Learning for Recovery of Block-Sparse Signals
Fang, Jun, Shen, Yanning, Li, Hongbin, Wang, Pu
We consider the problem of recovering block-sparse signals whose structures are unknown \emph{a priori}. Block-sparse signals with nonzero coefficients occurring in clusters arise naturally in many practical scenarios. However, the knowledge of the block structure is usually unavailable in practice. In this paper, we develop a new sparse Bayesian learning method for recovery of block-sparse signals with unknown cluster patterns. Specifically, a pattern-coupled hierarchical Gaussian prior model is introduced to characterize the statistical dependencies among coefficients, in which a set of hyperparameters are employed to control the sparsity of signal coefficients. Unlike the conventional sparse Bayesian learning framework in which each individual hyperparameter is associated independently with each coefficient, in this paper, the prior for each coefficient not only involves its own hyperparameter, but also the hyperparameters of its immediate neighbors. In doing this way, the sparsity patterns of neighboring coefficients are related to each other and the hierarchical model has the potential to encourage structured-sparse solutions. The hyperparameters, along with the sparse signal, are learned by maximizing their posterior probability via an expectation-maximization (EM) algorithm. Numerical results show that the proposed algorithm presents uniform superiority over other existing methods in a series of experiments.
Nonparametric Multi-group Membership Model for Dynamic Networks
Kim, Myunghwan, Leskovec, Jure
Relational data-like graphs, networks, and matrices-is often dynamic, where the relational structure evolves over time. A fundamental problem in the analysis of time-varying network data is to extract a summary of the common structure and the dynamics of the underlying relations between the entities. Here we build on the intuition that changes in the network structure are driven by the dynamics at the level of groups of nodes. We propose a nonparametric multi-group membership model for dynamic networks. Our model contains three main components: We model the birth and death of individual groups with respect to the dynamics of the network structure via a distance dependent Indian Buffet Process. We capture the evolution of individual node group memberships via a Factorial Hidden Markov model. And, we explain the dynamics of the network structure by explicitly modeling the connectivity structure of groups. We demonstrate our model's capability of identifying the dynamics of latent groups in a number of different types of network data. Experimental results show that our model provides improved predictive performance over existing dynamic network models on future network forecasting and missing link prediction.
Unsupervised learning human's activities by overexpressed recognized non-speech sounds
Smidtas, Serge, Peyrot, Magalie
Human activity and environment produces sounds such as, at home, the noise produced by water, cough, or television. These sounds can be used to determine the activity in the environment. The objective is to monitor a person's activity or determine his environment using a single low cost microphone by sound analysis. The purpose is to adapt programs to the activity or environment or detect abnormal situations. Some patterns of over expressed repeatedly in the sequences of recognized sounds inter and intra environment allow to characterize activities such as the entrance of a person in the house, or a tv program watched. We first manually annotated 1500 sounds of daily life activity of old persons living at home recognized sounds. Then we inferred an ontology and enriched the database of annotation with a crowed sourced manual annotation of 7500 sounds to help with the annotation of the most frequent sounds. Using learning sound algorithms, we defined 50 types of the most frequent sounds. We used this set of recognizable sounds as a base to tag sounds and put tags on them. By using over expressed number of motifs of sequences of the tags, we were able to categorize using only a single low-cost microphone, complex activities of daily life of a persona at home as watching TV, entrance in the apartment of a person, or phone conversation including detecting unknown activities as repeated tasks performed by users.
Stochastic blockmodel approximation of a graphon: Theory and consistent estimation
Airoldi, Edoardo M, Costa, Thiago B, Chan, Stanley H
Non-parametric approaches for analyzing network data based on exchangeable graph models (ExGM) have recently gained interest. The key object that defines an ExGM is often referred to as a graphon. This non-parametric perspective on network modeling poses challenging questions on how to make inference on the graphon underlying observed network data. In this paper, we propose a computationally efficient procedure to estimate a graphon from a set of observed networks generated from it. This procedure is based on a stochastic blockmodel approximation (SBA) of the graphon. We show that, by approximating the graphon with a stochastic block model, the graphon can be consistently estimated, that is, the estimation error vanishes as the size of the graph approaches infinity.
Adaptive Measurement-Based Policy-Driven QoS Management with Fuzzy-Rule-based Resource Allocation
Yerima, Suleiman Y., Parr, Gerard P., McClean, Sally I., Morrow, Philip J.
Fixed and wireless networks are increasingly converging towards common connectivity with IP-based core networks. Providing effective end-to-end resource and QoS management in such complex heterogeneous converged network scenarios requires unified, adaptive and scalable solutions to integrate and co-ordinate diverse QoS mechanisms of different access technologies with IP-based QoS. Policy-Based Network Management (PBNM) is one approach that could be employed to address this challenge. Hence, a policy-based framework for end-to-end QoS management in converged networks, CNQF (Converged Networks QoS Management Framework) has been proposed within our project. In this paper, the CNQF architecture, a Java implementation of its prototype and experimental validation of key elements are discussed. We then present a fuzzy-based CNQF resource management approach and study the performance of our implementation with real traffic flows on an experimental testbed. The results demonstrate the efficacy of our resource-adaptive approach for practical PBNM systems.
OnDroad Planner: Building Tourist Plans Using Traveling Social Network Information
Cenamor, Isabel (Universidad Carlos III de Madrid) | Rosa, Tomás de la (Universidad Carlos III de Madrid) | Borrajo, Daniel (Universidad Carlos III de Madrid)
One of the key challenges in automated planning is to define the sources of information that will feed the initial state and goals of each planning task. In many domains, the information comes from company's databases. In other applications, the information is harder to obtain and it is usually partial. In this paper, we will describe an application on travel planning, where the initial state and goals will be obtained by crowdsourcing. Travel planning requires the use of plenty Internet-based resources; some of them are related to human generated opinions on all kinds of matters (e.g. hotels, places to visit, restaurants, ...). We present the OnDroad planner, a system that creates personalized tourist plans using the human generated information gathered from the minube traveling social network. OnDroad proposes an initial tourist guide according to the recommendation of the users profiles and their contacts. In addition, this guide can be continuously updated with newly generated data.
Discovery of Player Strategies in a Serious Game
Li, Hua (SAIC) | Munoz-Avila, Hector (Lehigh University) | Ke, Lei (SAIC) | Symborski, Carl (SAIC) | Alonso, Rafael (SAIC)
Serious games are popular computer games that frequently simulate real-world events or processes designed for the purpose of solving a problem. Although they are often entertaining, their main purpose is to train or educate users. Not surprisingly, users exhibit different game play behaviors because of their diverse background and game experience. To improve the educational effectiveness of these games, it is important to understand and learn from the interaction between the users and the game engine. This paper presents a study attempting to apply machine learning techniques to the game log to discover: a) strategies that are common to players interacting with serious games and b) variances in the demographics of the player base for these strategies. This is an empirical study with end-user data while playing Missing, a serious game developed to help mitigate biases that people may exhibit when analyzing plausible hypothesis for observed events. We found a set of common strategies and interesting variances in player demographics associated with these strategies.