Tjeerd C. Andringa

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This paper presents a smart surveillance system named CASSANDRA, aimed at detecting instances of aggressive human behavior in public environments. A distinguishing aspect of CASSANDRA is the exploitation of the compli-mentary nature of audio and video sensing to disambiguate scene activity in real-life, noisy and dynamic environments. At the lower level,(More)
Cognitive skills, such as processing speed, memory functioning, and the ability to divide attention, are known to diminish with aging. The present study shows that, despite these changes, older adults can successfully compensate for degradations in speech perception. Critically, the older participants of this study were not pre-selected for high performance(More)
A central problem in automatic sound recognition is the mapping between low-level audio features and the meaningful content of an auditory scene. We propose a dynamic network model to perform this mapping. In acoustics, much research has been devoted to low-level perceptual abilities such as audio feature extraction and grouping, which have been translated(More)
A recognition system for environmental sounds is presented. Signal-driven classification is performed by applying machine-learning techniques on features extracted from a cochleogram. These possibly unreliable classifications are improved by creating expectancies of sound events based on context information. We present the results of an experiment where(More)
A central problem in automatic sound recognition is the mapping between low-level audio features and the meaningful content of an auditory scene. We propose a dynamic network model to perform this mapping. In acoustics, much research is devoted to low-level perceptual abilities such as audio feature extraction and grouping, which are translated into(More)
The paper presents a knowledge-based system designed to detect evidence of aggression by means of audio analysis. The detection is based on the way sounds are analyzed and how they attract attention in the human auditory system. The performance achieved is comparable to human performance in complex social environments. The SIgard system has been deployed in(More)
Temporal integration is the perceptual process combining sensory stimulation over time into longer percepts that can span over 10 times the duration of a minimally detectable stimulus. Particularly in the auditory domain, such "long-term" temporal integration has been characterized as a relatively simple function that acts chiefly to bridge brief input(More)
This theoretical paper addresses the cognitive functions via which quiet and in general pleasurable sounds promote and annoying sounds impede health. The article comprises a literature analysis and an interpretation of how the bidirectional influence of appraising the environment and the feelings of the perceiver can be understood in terms of core affect(More)
— Agents that operate in a real-world environment have to process an abundance of information, which may be ambiguous or noisy. We present a method inspired by cognitive research that keeps track of sensory information, and interprets it with knowledge of the context. We test this model on visual information from the real-world environment of a mobile robot(More)
This paper presents a smart surveillance system named CASSANDRA, aimed at detecting instances of aggressive human behavior in public environments. A distinguishing aspect of CASSANDRA is the exploitation of complementary audio and video cues to disambiguate scene activity in real-life environments. From the video side, the system uses overlapping cameras to(More)