Information Fusion
Assessing and Characterizing the Cognitive Power of Machine Consciousness Implementations
Arrabales, Raul (Carlos III University of Madrid) | Ledezma, Agapito (Carlos III University of Madrid) | Sanchis, Araceli (Carlos III University of Madrid)
Many aspects can be taken into account in order to assess the power and potential of a cognitive architecture. In this paper we argue that ConsScale, a cognitive scale inspired on the development of consciousness, can be used to characterize and evaluate cognitive architectures from the point of view of the effective integration of their cognitive functionalities. Additionally, a graphical characterization of the cognitive power of artificial agents is proposed as a helpful tool for the analysis and comparison of Machine Consciousness implementations. This is illustrated with the application of the scale to a particular problem domain in the context of video game synthetic bots.
On Chase Termination Beyond Stratification
Meier, Michael, Schmidt, Michael, Lausen, Georg
We study the termination problem of the chase algorithm, a central tool in various database problems such as the constraint implication problem, Conjunctive Query optimization, rewriting queries using views, data exchange, and data integration. The basic idea of the chase is, given a database instance and a set of constraints as input, to fix constraint violations in the database instance. It is well-known that, for an arbitrary set of constraints, the chase does not necessarily terminate (in general, it is even undecidable if it does or not). Addressing this issue, we review the limitations of existing sufficient termination conditions for the chase and develop new techniques that allow us to establish weaker sufficient conditions. In particular, we introduce two novel termination conditions called safety and inductive restriction, and use them to define the so-called T-hierarchy of termination conditions. We then study the interrelations of our termination conditions with previous conditions and the complexity of checking our conditions. This analysis leads to an algorithm that checks membership in a level of the T-hierarchy and accounts for the complexity of termination conditions. As another contribution, we study the problem of data-dependent chase termination and present sufficient termination conditions w.r.t. fixed instances. They might guarantee termination although the chase does not terminate in the general case. As an application of our techniques beyond those already mentioned, we transfer our results into the field of query answering over knowledge bases where the chase on the underlying database may not terminate, making existing algorithms applicable to broader classes of constraints.
Online Learning of Spacecraft Simulation Models
Thomas, Justin R. (United Space Alliance) | Eick, Christoph F. (University of Houston)
Spacecraft simulation is an integral part of NASA mission planning, real-time mission support, training, and systems engineering. Existing approaches that power these simulations cannot quickly react to the dynamic and complex behavior of the International Space Station (ISS). To address this problem, this paper introduces a unique and efficient method for continuously learning highly accurate models from real-time streaming sensor data, relying on an online learning approach. This approach revolutionizes NASA simulation techniques for space missions by providing models that quickly adapt to real-world feedback without human intervention. A novel regional sliding-window technique for online learning of simulation models is proposed that regionally maintains the most recent data. We also explore a knowledge fusion approach to reduce predictive error spikes when confronted with making predictions in situations that are quite different from training scenarios. We demonstrate substantial error reductions up to 74% in our experimental evaluation on the ISS Electrical Power System and discuss the early deployment of our software in the ISS Mission Control Center (MCC) for ground-based simulations.
Bayesian Knowledge Fusion
Santos, Eugene (Dartmouth College) | Wilkinson, John T. (Dartmouth College) | Santos, Eunice E. (Virginia Polytechnic Institute and State University)
We address the problem of information fusion in uncertain environments. Imagine there are multiple experts building probabilistic models of the same situation and we wish to aggregate the information they provide. There are several problems we may run into by naively merging the information from each. For example, the experts may disagree on the probability of a certain event or they may disagree on the direction of causility between two events (e.g., one thinks A causes B while another thinks B causes A). They may even disagree on the entire structure of dependencies among a set of variables in a probabilistic network. In our proposed solution to this problem, we represent the probabilistic models as Bayesian Knowledge Bases (BKBs) and propose an algorithm called Bayesian knowledge fusion that allows the fusion of multiple BKBs into a single BKB that retains the information from all input sources. This allows for easy aggregation and de-aggregation of information from multiple expert sources and facilitates multi-expert decision making by providing a framework in which all opinions can be preserved and reasoned over.
Augmented Cyberspace Exploiting Real-time Biological Sensor Fusion
Sakurai, Yoshitaka (Tokyo Denki University) | Takada, Kouhei (Tokyo Denki University) | Hashida, Shoko (Meiji University) | Tsuruta, Setsuo (Tokyo Denki University)
In Web-based CSCW (Computer-Supported Cooperative Work) often including cooperative learning, remote members communicate their intentions in cyberspace, using textual sentences, pictures and voice. However, often, communication between members cannot be correctly done and interface errors occur. Different from face-to-face communication, partners' situations including their interest, concentration, boredom, and tiredness cannot be easily transmitted. Oversight and mishearing of remote partners is often overlooked. Besides, it is further difficult to understand their real intentions sufficiently. To overcome these problems, “Augmented Cyberspace” for dependable Web-based CSCW Systems, is proposed, which is also applicable to system such as e-learning, e-commerce, etc. This assesses situations of remote users through timely fusing information of multiple biological sensors and the related contexts. By exploiting the timely assessment, the system augments the cyberspace through emphasizing the situation of remote users or providing warnings in conventional media such as text, image, and voice. Experimental results showed the necessity and feasibility of such assessment by information fusion of multiple sensors.
Data Integration for Classification Problems Employing Gaussian Process Priors
Girolami, Mark, Zhong, Mingjun
By adopting Gaussian process priors a fully Bayesian solution to the problem of integrating possibly heterogeneous data sets within a classification setting is presented. Approximate inference schemes employing Variational & Expectation Propagation based methods are developed and rigorously assessed. We demonstrate our approach to integrating multiple data sets on a large scale protein fold prediction problem where we infer the optimal combinations of covariance functions and achieve state-of-the-art performance without resorting to any ad hoc parameter tuning and classifier combination.
Data Integration for Classification Problems Employing Gaussian Process Priors
Girolami, Mark, Zhong, Mingjun
By adopting Gaussian process priors a fully Bayesian solution to the problem of integrating possibly heterogeneous data sets within a classification setting is presented. Approximate inference schemes employing Variational & Expectation Propagation based methods are developed and rigorously assessed. We demonstrate our approach to integrating multiple data sets on a large scale protein fold prediction problem where we infer the optimal combinations of covariance functions and achieve state-of-the-art performance without resorting to any ad hoc parameter tuning and classifier combination.
Learning Semantic Definitions of Online Information Sources
Carman, M. J., Knoblock, C. A.
The Internet contains a very large number of information sources providing many types of data from weather forecasts to travel deals and financial information. These sources can be accessed via Web-forms, Web Services, RSS feeds and so on. In order to make automated use of these sources, we need to model them semantically, but writing semantic descriptions for Web Services is both tedious and error prone. In this paper we investigate the problem of automatically generating such models. We introduce a framework for learning Datalog definitions of Web sources. In order to learn these definitions, our system actively invokes the sources and compares the data they produce with that of known sources of information. It then performs an inductive logic search through the space of plausible source definitions in order to learn the best possible semantic model for each new source. In this paper we perform an empirical evaluation of the system using real-world Web sources. The evaluation demonstrates the effectiveness of the approach, showing that we can automatically learn complex models for real sources in reasonable time. We also compare our system with a complex schema matching system, showing that our approach can handle the kinds of problems tackled by the latter.
Exploiting Social Annotation for Automatic Resource Discovery
Plangprasopchok, Anon, Lerman, Kristina
Information integration applications, such as mediators or mashups, that require access to information resources currently rely on users manually discovering and integrating them in the application. Manual resource discovery is a slow process, requiring the user to sift through results obtained via keyword-based search. Although search methods have advanced to include evidence from document contents, its metadata and the contents and link structure of the referring pages, they still do not adequately cover information sources -- often called "the hidden Web"-- that dynamically generate documents in response to a query. The recently popular social bookmarking sites, which allow users to annotate and share metadata about various information sources, provide rich evidence for resource discovery. In this paper, we describe a probabilistic model of the user annotation process in a social bookmarking system del.icio.us. We then use the model to automatically find resources relevant to a particular information domain. Our experimental results on data obtained from del.icio.us