276 research outputs found

    A Reinforcement Learning Agent for Minutiae Extraction from Fingerprints

    Get PDF
    In this paper we show that reinforcement learning can be used for minutiae detection in fingerprint matching. Minutiae are characteristic features of fingerprints that determine their uniqueness. Classical approaches use a series of image processing steps for this task, but lack robustness because they are highly sensitive to noise and image quality. We propose a more robust approach, in which an autonomous agent walks around in the fingerprint and learns how to follow ridges in the fingerprint and how to recognize minutiae. The agent is situated in the environment, the fingerprint, and uses reinforcement learning to obtain an optimal policy. Multi-layer perceptrons are used for overcoming the difficulties of the large state space. By choosing the right reward structure and learning environment, the agent is able to learn the task. One of the main difficulties is that the goal states are not easily specified, for they are part of the learning task as well. That is, the recognition of minutiae has to be learned in addition to learning how to walk over the ridges in the fingerprint. Results of successful first experiments are presented

    Gaze Behavior, Believability, Likability and the iCat

    Get PDF

    Use of wireless sensor networks for distributed event detection in disaster management applications

    Get PDF
    Recently, wireless sensor networks (WSNs) have become mature enough to go beyond being simple fine-grained continuous monitoring platforms and have become one of the enabling technologies for early-warning disaster systems. Event detection functionality of WSNs can be of great help and importance for (near) real-time detection of, for example, meteorological natural hazards and wild and residential fires. From the data-mining perspective, many real world events exhibit specific patterns, which can be detected by applying machine learning (ML) techniques. In this paper, we introduce ML techniques for distributed event detection in WSNs and evaluate their performance and applicability for early detection of disasters, specifically residential fires. To this end, we present a distributed event detection approach incorporating a novel reputation-based voting and the decision tree and evaluate its performance in terms of detection accuracy and time complexity

    A First Step toward the Automatic Understanding of Social Touch for Naturalistic Human–Robot Interaction

    Get PDF
    Social robots should be able to automatically understand and respond to human touch. The meaning of touch does not only depend on the form of touch but also on the context in which the touch takes place. To gain more insight into the factors that are relevant to interpret the meaning of touch within a social context we elicited touch behaviors by letting participants interact with a robot pet companion in the context of different affective scenarios. In a contextualized lab setting, participants (n = 31) acted as if they were coming home in different emotional states (i.e., stressed, depressed, relaxed, and excited) without being given specific instructions on the kinds of behaviors that they should display. Based on video footage of the interactions and interviews we explored the use of touch behaviors, the expressed social messages, and the expected robot pet responses. Results show that emotional state influenced the social messages that were communicated to the robot pet as well as the expected responses. Furthermore, it was found that multimodal cues were used to communicate with the robot pet, that is, participants often talked to the robot pet while touching it and making eye contact. Additionally, the findings of this study indicate that the categorization of touch behaviors into discrete touch gesture categories based on dictionary definitions is not a suitable approach to capture the complex nature of touch behaviors in less controlled settings. These findings can inform the design of a behavioral model for robot pet companions and future directions to interpret touch behaviors in less controlled settings are discussed

    Bacteria Hunt: A multimodal, multiparadigm BCI game

    Get PDF
    Brain-Computer Interfaces (BCIs) allow users to control applications by brain activity. Among their possible applications for non-disabled people, games are promising candidates. BCIs can enrich game play by the mental and affective state information they contain. During the eNTERFACE’09 workshop we developed the Bacteria Hunt game which can be played by keyboard and BCI, using SSVEP and relative alpha power. We conducted experiments in order to investigate what difference positive vs. negative neurofeedback would have on subjects’ relaxation states and how well the different BCI paradigms can be used together. We observed no significant difference in mean alpha band power, thus relaxation, and in user experience between the games applying positive and negative feedback. We also found that alpha power before SSVEP stimulation was significantly higher than alpha power during SSVEP stimulation indicating that there is some interference between the two BCI paradigms

    Chloride-induced corrosion of steel in concrete -- insights from bimodal neutron and X-ray microtomography combined with ex-situ microscopy

    Full text link
    The steel-concrete interface (SCI) is known to play a major role in corrosion of steel in concrete, but a fundamental understanding is still lacking. One reason is that concrete's opacity complicates the study of internal processes. Here, we report on the application of bimodal X-ray and neutron microtomography as in-situ imaging techniques to elucidate the mechanism of steel corrosion in concrete. The study demonstrates that the segmentation of the specimen components of relevance - steel, cementitious matrix, aggregates, voids, corrosion products - obtained through bimodal X-ray and neutron imaging is more reliable than that based on the results of each of the two techniques separately. Further, we suggest the combination of tomographic in-situ imaging with ex-situ SEM analysis of targeted sections, selected on the basis of the segmented tomograms. These in-situ and ex-situ characterization techniques were applied to study localized corrosion in a very early stage, on reinforced concrete cores retrieved from a concrete bridge. A number of interesting observations were made. First, the acquired images revealed the formation of several corrosion sites close to each other. Second, the morphology of the corrosion pits was relatively shallow. Finally, only about half of the total 31 corrosion initiation spots were in close proximity to interfacial macroscopic air voids, and above 90 percent of the more than 160 interfacial macroscopic air voids were free from corrosion. The findings have implications for the mechanistic understanding of corrosion of steel in concrete and suggest that multimodal in-situ imaging is a valuable technique for further related studies

    The role of Comprehension in Requirements and Implications for Use Case Descriptions

    Get PDF
    Within requirements engineering it is generally accepted that in writing specifications (or indeed any requirements phase document), one attempts to produce an artefact which will be simple to comprehend for the user. That is, whether the document is intended for customers to validate requirements, or engineers to understand what the design must deliver, comprehension is an important goal for the author. Indeed, advice on producing ‘readable’ or ‘understandable’ documents is often included in courses on requirements engineering. However, few researchers, particularly within the software engineering domain, have attempted either to define or to understand the nature of comprehension and it’s implications for guidance on the production of quality requirements. Therefore, this paper examines thoroughly the nature of textual comprehension, drawing heavily from research in discourse process, and suggests some implications for requirements (and other) software documentation. In essence, we find that the guidance on writing requirements, often prevalent within software engineering, may be based upon assumptions which are an oversimplification of the nature of comprehension. Hence, the paper examines guidelines which have been proposed, in this case for use case descriptions, and the extent to which they agree with discourse process theory; before suggesting refinements to the guidelines which attempt to utilise lessons learned from our richer understanding of the underlying discourse process theory. For example, we suggest subtly different sets of writing guidelines for the different tasks of requirements, specification and design

    The effectiveness of two novel approaches to prevent intrusions: A pilot study comparing Tetris_dualtask and imagery rescripting to control

    Get PDF
    Background and objectives: Post-traumatic stress disorder (PTSD) is a global health problem. Although effective treatments for it exist, early interventions that prevent PTSD from developing are lacking. The aim of this pilot analogue trauma study was to compare the effects of two potential early intervention strategies, namely Tetris_dualtask and imagery rescripting (IR) to a no-intervention control group on intrusion frequency and the vividness and emotionality of aversive film memory. Methods: Sixty healthy students were subjected to the trauma film paradigm and randomly allocated to either: Tetris_dualtask, IR or no-intervention. Main outcomes were the number of film-related intrusions at one week and vividness and emotionality ratings of the most aversive film memory. Secondary outcomes were PTSD-like symptoms, intrusion intensity, and explicit film memory. Results: The Tetris_dualtask group reported significant fewer intrusions compared to the no-intervention group; whereas the IR group did not. No effect was found on vividness and emotionality ratings, PTSD-like symptoms, intrusion intensity, and explicit memory. Limitations: The sample size was small, and analogue trauma in healthy individuals was examined, thus generalizability may be limited. Also, to increase comparability between interventions, the duration of Tetris_dualtask and IR was standardized. As a result, the IR intervention was shorter compared to other studies, which might have decreased its efficacy. Conclusions: The results of this pilot study suggest that playing Tetris during retrieval of traumatic images, might hold potential as an early intervention strategy to reduce intrusions in the early aftermath of trauma and adversity. However, future large-scale replication research is needed
    corecore