Europe
A Neural-Symbolic Cognitive Agent for Online Learning and Reasoning
Penning, H. Leo H. de (TNO Behaviour and Societal Sciences) | Garcez, Artur S. d' (London City University) | Avila (UFRGS, Porto Alegre) | Lamb, Luis C. (Utrecht University) | Meyer, John-Jules C.
In real-world applications, the effective integration of learning and reasoning in a cognitive agent model is a difficult task. However, such integration may lead to a better understanding, use and construction of more realistic models. Unfortunately, existing models are either oversimplified or require much processing time, which is unsuitable for online learning and reasoning. Currently, controlled environments like training simulators do not effectively integrate learning and reasoning. In particular, higher-order concepts and cognitive abilities have many unknown temporal relations with the data, making it impossible to represent such relationships by hand. We introduce a novel cognitive agent model and architecture for online learning and reasoning that seeks to effectively represent, learn and reason in complex training environments. The agent architecture of the model combines neural learning with symbolic knowledge representation. It is capable of learning new hypotheses from observed data, and infer new beliefs based on these hypotheses. Furthermore, it deals with uncertainty and errors in the data using a Bayesian inference model. The validation of the model on real-time simulations and the results presented here indicate the promise of the approach when performing online learning and reasoning in real-world scenarios, with possible applications in a range of areas.
A Hierarchical Architecture for Adaptive Brain-Computer Interfacing
Chung, Mike (University of Washington) | Cheung, Willy (University of Washington) | Scherer, Reinhold (Graz University of Technology) | Rao, Rajesh P. N. (University of Washington)
Brain-computer interfaces (BCIs) allow a user to directly control devices such as cursors and robots using brain signals. Non-invasive BCIs, e.g., those based on electroencephalographic (EEG) signals recorded from the scalp, suffer from low signal-to-noise ratio which limits the bandwidth of control. Invasive BCIs allow fine-grained control but can leave users exhausted since control is typically exerted on a moment-by-moment basis. In this paper, we address these problems by proposing a new adaptive hierarchical architecture for brain-computer interfacing. The approach allows a user to teach the BCI new skills on-the-fly; these learned skills are later invoked directly as high-level commands, relieving the user of tedious low-level control. We report results from four subjects who used a hierarchical EEG-based BCI to successfully train and control a humanoid robot in a virtual home environment. Gaussian processes were used for learning high-level commands, allowing a BCI to switch between autonomous and user-guided modes based on the current estimate of uncertainty. We also report the first instance of multi-tasking in a BCI, involving simultaneous control of two different devices by a single user. Our results suggest that hierarchical BCIs can provide a flexible and robust way of controlling complex robotic devices in real-world environments.
Just an Artifact: Why Machines are Perceived as Moral Agents
Bryson, Joanna J. (University of Bath) | Kime, Philip P. (Independent Researcher)
How obliged can we be to AI, and how much danger does it pose us? A surprising proportion of our society holds exaggerated fears or hopes for AI, such as the fear of robot world conquest, or the hope that AI will indefinitely perpetuate our culture. These misapprehensions are symptomatic of a larger problem—a confusion about the nature and origins of ethics and its role in society. While AI technologies do pose promises and threats, these are not qualitatively different from those posed by other artifacts of our culture which are largely ignored: from factories to advertising, weapons to political systems. Ethical systems are based on notions of identity, and the exaggerated hopes and fears of AI derive from our cultures having not yet accommodated the fact that language and reasoning are no longer uniquely human. The experience of AI may improve our ethical intuitions and self-understanding, potentially helping our societies make better-informed decisions on serious ethical dilemmas.
Explaining Genetic Knock-Out Effects Using Cost-Based Abduction
Andrews, Emad Abdel-Thalooth (University of Toronto) | Bonner, Anthony (University of Toronto)
Cost-Based Abduction (CBA) is an AI model for reasoning under uncertainty. In CBA, evidence to be explained is treated as a goal which is true and must be proven. Each proof of the goal is viewed as a feasible explanation and has a cost equal to the sum of the costs of all hypotheses that are assumed to complete the proof. The aim is to find the Least Cost Proof. This paper uses CBA to develop a novel method for modeling Genetic Regulatory Networks (GRN) and explaining genetic knock-out effects. Constructing GRN using multiple data sources is a fundamental problem in computational biology. We show that CBA is a powerful formalism for modeling GRN that can easily and effectively integrate multiple sources of biological data. In this paper, we use three different biological data sources: Protein-DNA, Protein–Protein and gene knock-out data. Using this data, we first create an un-annotated graph; CBA then annotates the graph by assigning a sign and a direction to each edge. Our biological results are promising; however, this manuscript focuses on the mathematical modeling of the application. The advantages of CBA and its relation to Bayesian inference are also presented.
Finding "Unexplained" Activities in Video
Albanese, Massimiliano (University of Maryland) | Molinaro, Cristian (University of Maryland) | Persia, Fabio (Università) | Picariello, Antonio (di Napoli Federico II) | Subrahmanian, V.S. (Università)
Consider a video surveillance application that monitors some location. The application knows a set of activity models (that are either normal or abnormal or both), but in addition, the application wants to find video segments that are unexplained by any of the known activity models — these unexplained video segments may correspond to activities for which no previous activity model existed. In this paper, we formally define what it means for a given video segment to be unexplained (totally or partially) w.r.t. a given set of activity models and a probability threshold. We develop two algorithms – FindTUA and FindPUA – to identify Totally and Partially Unexplained Activities respectively, and show that both algorithms use important pruning methods. We report on experiments with a prototype implementation showing that the algorithms both run efficiently and are accurate.
Diversity Regularized Machine
Yu, Yang (Nanjing University) | Li, Yu-Feng (Nanjing University) | Zhou, Zhi-Hua (Nanjing University)
Ensemble methods, which train multiple learners for a task, are among the state-of-the-art learning approaches. The diversity of the component learners has been recognized as a key to a good ensemble, and existing ensemble methods try different ways to encourage diversity, mostly by heuristics. In this paper, we propose the diversity regularized machine (DRM) in a mathematical programming framework, which efficiently generates an ensemble of diverse support vector machines (SVMs). Theoretical analysis discloses that the diversity constraint used in DRM can lead to an effective reduction on its hypothesis space complexity, implying that the diversity control in ensemble methods indeed plays a role of regularization as in popular statistical learning approaches. Experiments show that DRM can significantly improve generalization ability and is superior to some state-of-the-art SVM ensemble methods.
Dealing with Concept Drift and Class Imbalance in Multi-Label Stream Classification
Spyromitros-Xioufis, Eleftherios (Aristotle University of Thessaloniki) | Spiliopoulou, Myra (Otto-von-Guericke University of Magdeburg) | Tsoumakas, Grigorios (Aristotle University of Thessaloniki) | Vlahavas, Ioannis (Aristotle University of Thessaloniki)
Data streams containing objects that are (or can be) associated with more than one label at the same time are ubiquitous. In spite of its important applications, classification of streaming multi-label data is largely unexplored. Existing approaches try to tackle the problem by transferring traditional single-label stream classification practices to the multi-label domain. Nevertheless, they fail to consider some of the unique properties of the problem such as within and between class imbalance and multiple concept drift. To deal with these challenges, this paper proposes a novel multi-label stream classification approach that employs two windows for each label, one for positive and one for negative examples. Instance-sharing is exploited for space efficiency, while a time-efficient instantiation based on the k-Nearest Neighbor algorithm is also proposed. Finally, a batch-incremental thresholding technique is proposed to further deal with the class imbalance problem. Results of an empirical comparison against two other methods on three real world datasets are in favor of the proposed approach.
Learning Driving Behavior by Timed Syntactic Pattern Recognition
Verwer, Sicco (Katholieke Universiteit Leuven) | Weerdt, Mathijs de (Delft University of Technology) | Witteveen, Cees (Delft University of Technology)
The data at our disposal consists of onboard sensor measurements that have been collected from truck round-trips. We advocate the use of an explicit time representation By applying a simple discretization method, we obtain sequences in syntactic pattern recognition because it can of timed events. The behavior that is displayed in result in more succinct models and easier learning these sequences is unknown. From this data, we want to learn problems. We apply this approach to the real-world a model that we can use to monitor the driving behavior in problem of learning models for the driving behavior new data, i.e., to use it as a classifier. Our approach is to first of truck drivers. We discretize the values of learn a timed model from the unlabeled sequences using the onboard sensors into simple events.
Utility-Based Fraud Detection
Torgo, Luis (LIAAD - Inesc Porto LA) | Lopes, Elsa (LIAAD - Inesc Porto LA)
Fraud detection is a key activity with serious socio-economical impact. Inspection activities associated with this task are usually constrained by limited available resources. Data analysis methods can provide help in the task of deciding where to allocate these limited resources in order to optimise the outcome of the inspection activities. This paper presents a multi-strategy learning method to address the question of which cases to inspect first. The proposed methodology is based on the utility theory and provides a ranking ordered by decreasing expected outcome of inspecting the candidate cases. This outcome is a function not only of the probability of the case being fraudulent but also of the inspection costs and expected payoff if the case is confirmed as a fraud. The proposed methodology is general and can be useful on fraud detection activities with limited inspection resources. We experimentally evaluate our proposal on both an artificial domain and on a real world task.
Classification of Emerging Extreme Event Tracks in Multivariate Spatio-Temporal Physical Systems Using Dynamic Network Structures: Application to Hurricane Track Prediction
Sencan, Huseyin (North Carolina State University) | Chen, Zhengzhang (North Carolina State University) | Hendrix, William (Northwestern University) | Pansombut, Tatdow (North Carolina State University) | Semazzi, Frederick (North Carolina State University) | Choudhary, Alok (North Carolina State University) | Kumar, Vipin (University of Minnesota) | Melechko, Anatoli V. (North Carolina State University) | Samatova, Nagiza F. (Oak Ridge National Laboratory)
Understanding extreme events, such as hurricanes or forest fires, is of paramount importance because of their adverse impacts on human beings. Such events often propagate in space and time. Predicting-even a few days in advance-what locations will get affected by the event tracks could benefit our society in many ways. Arguably, simulations from “first principles,” where underlying physics-based models are described by a system of equations, provide least reliable predictions for variables characterizing the dynamics of these extreme events. Data-driven model building has been recently emerging as a complementary approach that could learn the relationships between historically observed or simulated multiple, spatio-temporal ancillary variables and the dynamic behavior of extreme events of interest. While promising, the methodology for predictive learning from such complex data is still in its infancy. In this paper, we propose a dynamic networks-based methodology for in-advance prediction of the dynamic tracks of emerging extreme events. By associating a network model of the system with the known tracks, our method is capable of learning the recurrent network motifs that could be used as discriminatory signatures for the event's behavioral class. When applied to classifying the behavior of the hurricane tracks at their early formation stages in Western Africa region, our method is able to predict whether hurricane tracks will hit the land of the North Atlantic region at least 10-15 days lead lag time in advance with more than 90% accuracy using 10-fold cross-validation. To the best of our knowledge, no comparable methodology exists for solving this problem using data-driven models.