Information Fusion
Target Type Tracking with PCR5 and Dempster's rules: A Comparative Analysis
Dezert, Jean, Tchamova, Albena, Smarandache, Florentin, Konstantinova, Pavlina
In this paper we consider and analyze the behavior of two combinational rules for temporal (sequential) attribute data fusion for target type estimation. Our comparative analysis is based on Dempster's fusion rule proposed in Dempster-Shafer Theory (DST) and on the Proportional Conflict Redistribution rule no. 5 (PCR5) recently proposed in Dezert-Smarandache Theory (DSmT). We show through very simple scenario and Monte-Carlo simulation, how PCR5 allows a very efficient Target Type Tracking and reduces drastically the latency delay for correct Target Type decision with respect to Demspter's rule. For cases presenting some short Target Type switches, Demspter's rule is proved to be unable to detect the switches and thus to track correctly the Target Type changes. The approach proposed here is totally new, efficient and promising to be incorporated in real-time Generalized Data Association - Multi Target Tracking systems (GDA-MTT) and provides an important result on the behavior of PCR5 with respect to Dempster's rule. The MatLab source code is provided in
Neuronal Spectral Analysis of EEG and Expert Knowledge Integration for Automatic Classification of Sleep Stages
Kerkeni, Nizar, Alexandre, Frederic, Bedoui, Mohamed Hedi, Bougrain, Laurent, Dogui, Mohamed
Being able to analyze and interpret signal coming from electroencephalogram (EEG) recording can be of high interest for many applications including medical diagnosis and Brain-Computer Interfaces. Indeed, human experts are today able to extract from this signal many hints related to physiological as well as cognitive states of the recorded subject and it would be very interesting to perform such task automatically but today no completely automatic system exists. In previous studies, we have compared human expertise and automatic processing tools, including artificial neural networks (ANN), to better understand the competences of each and determine which are the difficult aspects to integrate in a fully automatic system. In this paper, we bring more elements to that study in reporting the main results of a practical experiment which was carried out in an hospital for sleep pathology study. An EEG recording was studied and labeled by a human expert and an ANN. We describe here the characteristics of the experiment, both human and neuronal procedure of analysis, compare their performances and point out the main limitations which arise from this study.
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, โAugmented Cyberspaceโ 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.