Searched for: author%3A%22Lefter%2C+I.%22
(1 - 10 of 10)
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Lefter, I. (author), Burghouts, G.J. (author), Rothkrantz, L.J.M. (author)
This paper investigates how speech and gestures convey stress, and how they can be used for automatic stress recognition. As a first step, we look into how humans use speech and gestures to convey stress. In particular, for both speech and gestures, we distinguish between stress conveyed by the intended semantic message (e.g. spoken words for...
article 2016
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Lefter, I. (author), Burghouts, G.J. (author), Rothkrantz, L.J.M. (author)
Stressful situations are likely to occur at human operated service desks, as well as at human-computer interfaces used in public domain. Automatic surveillance can help notifying when extra assistance is needed. Human communication is inherently multimodal e.g. speech, gestures, facial expressions. It is expected that automatic surveillance...
article 2014
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Lefter, I. (author), Rothkrantz, L.J.M. (author), Burghouts, G.J. (author)
Multimodal fusion is a complex topic. For surveillance applications audio-visual fusion is very promising given the complementary nature of the two streams. However, drawing the correct conclusion from multi-sensor data is not straightforward. In previous work we have analysed a database with audio- visual recordings of unwanted behavior in...
article 2013
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Lefter, I. (author), Rothkrantz, L. (author), Somhorst, M. (author)
At this moment many surveillance systems are installed in public domains to control the safety of people and properties. They are constantly watched by human operators who are easily overloaded. To support the human operators, a surveillance system model is designed that detects suspicious behaviour in a non-public area. Its task is to alert the...
conference paper 2012
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Lefter, I. (author), Burghouts, G.J. (author), Rothkrantz, L.J.M. (author)
We propose a new method for audio-visual sensor fusion and apply it to automatic aggression detection. While a variety of definitions of aggression exist, in this paper we see it as any kind of behavior that has a disturbing effect on others. We have collected multi- and unimodal assessments by humans, who have given aggression scores on a 3...
conference paper 2012
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Lefter, I. (author), Burghouts, G.J. (author), Rothkrantz, L.J.M. (author)
The focus of this paper is finding a method to predict aggression using a multimodal system, given multiple unimodal features. The mechanism underlying multimodal sensor fusion is complex and not completely clear. We try to understand the process of fusion and make it more transparent. As a case study we use a database with audio-visual...
conference paper 2012
document
Lefter, I. (author), Rothkrantz, L.J.M. (author), Burghouts, G.J. (author)
By analyzing a multimodal (audio-visual) database with aggressive incidents in trains, we have observed that there are no trivial fusion algorithms to successfully predict multimodal aggression based on unimodal sensor inputs. We proposed a fusion framework that contains a set of intermediate level variables (meta-features) between the low level...
conference paper 2012
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Rothkrantz, L. (author), Lefter, I. (author)
The paper describes a surveillance system of cameras installed at lamppost of a military area. The surveillance system has been designed to detect unwanted visitors or suspicious behaviors. The area is composed of streets, building blocks and surrounded by gates and water. The video recordings are monitored by operators at regular times. Next...
conference paper 2011
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Lefter, I. (author), Rothkrantz, L.J.M. (author), Burghouts, G. (author), Yang, Z. (author), Wiggers, P. (author)
Automatic detection of aggressive situations has a high societal and scientific relevance. It has been argued that using data from multimodal sensors as for example video and sound as opposed to unimodal is bound to increase the accuracy of detections. We approach the problem of multimodal aggression detection from the viewpoint of a human...
conference paper 2011
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Lefter, I. (author), Rothkrantz, L.J.M. (author), Wiggers, P. (author), van Leeuwen, D.A. (author), TNO Defensie en Veiligheid (author)
We explore possibilities for enhancing the generality, portability and robustness of emotion recognition systems by combining data-bases and by fusion of classifiers. In a first experiment, we investigate the performance of an emotion detection system tested on a certain database given that it is trained on speech from either the same database,...
conference paper 2010
Searched for: author%3A%22Lefter%2C+I.%22
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