| 1. |
- Alirezaie, Marjan, 1980-
(författare)
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Bridging the Semantic Gap between Sensor Data and Ontological Knowledge
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The rapid growth of sensor data can potentially enable a better awareness of the environment for humans. In this regard, interpretation of data needs to be human-understandable. For this, data interpretation may include semantic annotations that hold the meaning of numeric data. This thesis is about bridging the gap between quantitative data and qualitative knowledge to enrich the interpretation of data. There are a number of challenges which make the automation of the interpretation process non-trivial. Challenges include the complexity of sensor data, the amount of available structured knowledge and the inherent uncertainty in data. Under the premise that high level knowledge is contained in ontologies, this thesis investigates the use of current techniques in ontological knowledge representation and reasoning to confront these challenges. Our research is divided into three phases, where the focus of the first phase is on the interpretation of data for domains which are semantically poor in terms of available structured knowledge. During the second phase, we studied publicly available ontological knowledge for the task of annotating multivariate data. Our contribution in this phase is about applying a diagnostic reasoning algorithm to available ontologies. Our studies during the last phase have been focused on the design and development of a domain-independent ontological representation model equipped with a non-monotonic reasoning approach with the purpose of annotating time-series data. Our last contribution is related to coupling the OWL-DL ontology with a non-monotonic reasoner. The experimental platforms used for validation consist of a network of sensors which include gas sensors whose generated data is complex. A secondary data set includes time series medical signals representing physiological data, as well as a number of publicly available ontologies such as NCBO Bioportal repository.
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| 2. |
- Andersson, Thord, 1972-, et al.
(författare)
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Fuzzy matching of visual cues in an unmanned airborne vehicle
- 1999
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Computer vision systems used in autonomous mobile vehicles are typically linked to higher-level deliberation processes. One important aspect of this link is how to connect, or anchor, the symbols used at the higher level to the objects in the vision system that these symbols refer to. Anchoring is complicated by the fact that the vision data are inherently affected by uncertainty. We propose an anchoring technique that uses fuzzy sets to represent the uncertainty in the perceptual data. We show examples where this technique allows a deliberative system to reason about the objects (cars) detected by a vision system embarked in an unmanned helicopter, in the framework of the Witas project.
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| 3. |
- Broxvall, Mathias, et al.
(författare)
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An ecological approach to odour recognition in intelligent environments
- 2006
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Ingår i: 2006 IEEE International Conference on Robotics and automation, ICRA 2006. - 0780395050 ; , s. 2066-2071
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Konferensbidrag (refereegranskat)abstract
- We present a new approach for odour detection and recognition based on a so-called PEIS-Ecology: a network of gas sensors and a mobile robot are integrated in an intelligent environment. The environment can provide information regarding the location of potential odour sources, which is then relayed to a mobile robot equipped with an electronic nose. The robot can then perform a more thorough analysis of the odour character. This is a novel approach which alleviates some the challenges in mobile olfaction techniques by single and embedded mobile robots. The environment also provides contextual information which can be used to constrain the learning of odours, which is shown to improve classification performance.
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| 4. |
- Broxvall, Mathias, et al.
(författare)
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Have another look on failures and recovery planning in perceptual anchoring
- 2004
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Konferensbidrag (refereegranskat)abstract
- An important requirement for autonomous systems is the ability to detect and recover from exceptional situations such as failures in observations. In this paper we demonstrate how techniques for planning with sensing under uncertainty can play a major role in solving the problem of recovering from such situations. In this first step we concentrate on failures in perceptual anchoring, that is how to connect a symbol representing an object to the percepts of that object. We provide a classification of failures and present planning-based methods for recovering from them. We illustrate our approach by showing tests run on a mobile robot equipped with a color camera.
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| 5. |
- Broxvall, Mathias, et al.
(författare)
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Recovery planning for ambiguous cases in perceptual anchoring
- 2005
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Ingår i: Proceedings of the 20th national conference on Artificial intelligence, AAAI-05. - 9781577352365 ; , s. 1254-1260
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Konferensbidrag (refereegranskat)abstract
- An autonomous robot using symbolic reasoning, sensing and acting in a real environment needs the ability to create and maintain the connection between symbols representing objects in the world and the corresponding perceptual representations given by its sensors. This connection has been named perceptual anchoring. In complex environments, anchoring is not always easy to establish: the situation may often be ambiguous as to which percept actually corresponds to a given symbol. In this paper, we extend perceptual anchoring to deal robustly with ambiguous situations by providing general methods for detecting them and recovering from them. We consider different kinds of ambiguous situations and present planning-based methods to recover from them. We illustrate our approach by showing experiments involving a mobile robot equipped with a color camera and an electronic nose.
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| 6. |
- Chella, Antonio, et al.
(författare)
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Perceptual anchoring via conceptual spaces
- 2004
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Konferensbidrag (refereegranskat)abstract
- Perceptual anchoring is the problem of creating and maintaining in time the connection between symbols and sensor data that refer to the same physical objects. This is one of the facets of the general problem of integrating symbolic and non-symbolic processes in an intelligent system. Gärdenfors' conceptual spaces provide a geometric treatment of knowledge which bridges the gap between the symbolic and sub-symbolic approaches. As such, they can be used for the study of the anchoring problem. In this paper, we propose a computational framework for anchoring based on conceptual spaces. Our framework exploits the geometric structure of conceptual spaces for many of the crucial tasks of anchoring, like matching percepts to symbolic descriptions or tracking the evolution of objects over time.
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| 7. |
- Coradeschi, Silvia, et al.
(författare)
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A Decision-Mechanism for Reactive and Cooperating Soccer-Playing Agents
- 1997
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we present some preliminary results regarding a system for developing autonomous agents that combine reactivity to an uncertain and rapidly changing environment and commitment to prespecified tactics involving cooperation. A central requirement is that the behavior specification should be done by people who are not computer and AI specialists. The original application was air-combat simulation. Here we consider the simulated soccer domain in perspective of the RoboCup competition. The behavior of an agent is specified in terms of prioritized rules organized into a decision tree. Coordinated behaviors are encoded in the decision trees of the individual agents. What link individual behavior descriptions together are explicit communication and common means to describe the situation the agents are in.
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| 8. |
- Coradeschi, Silvia
(författare)
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A decision-mechanism for reactive and coordinated agents : Silvia Coradeschi
- 1997
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis we present preliminary results in the development of LIBRA (LInköping Behavior Representation for Agents). LIBRA is a rule-based system for specifying the behavior of automated agents that combine reactivity to an uncertain and rapidly changing envi-ronment and coordination. A central requirement is that the behavior specification should be made by users who are not computer and AI specialists. Two application domains are considered: air-combat simulation and a simulated soccer domain from the perspective of the RoboCup competition. The behavior of an agent is specified in terms of prioritized production rules organized in a decision tree. Coordinated behaviors are encoded in the decision trees of the individual agents. The agents initiate tactics depending on the situation and recognize the tactics that the other team members have initiated in order to take their part in it.What links individual behavior descriptions together are explicit communication and common means to describe the situation the agents find themselves in.
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| 9. |
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| 10. |
- Coradeschi, Silvia, et al.
(författare)
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An introduction to the anchoring problem
- 2003
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Ingår i: Robotics and Autonomous Systems. - 0921-8890 .- 1872-793X. ; 43:2-3, s. 85-96
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Tidskriftsartikel (refereegranskat)abstract
- Anchoring is the problem of connecting, inside an artificial system, symbols and sensor data that refer to the same physical objects in the external world. This problem needs to be solved in any robotic system that incorporates a symbolic component. However, it is only recently that the anchoring problem has started to be addressed as a problem per se, and a few general solutions have begun to appear in the literature. This paper introduces the special issue on perceptual anchoring of the Robotics and Autonomous Systems journal. Our goal is to provide a general overview of the anchoring problem, and to highlight some of its subtle points
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