In the recent past, service robots that are able to interact with humans in a natural way have become increasingly popular. A special kind of service robots that are designed for personal use at home are the so-called robot companions. They are expected to communicate with nonexpert users in natural and intuitive way. For such natural interactions with humans the robot has to detect communicati...

In a typical book review, I would look for and examine what is new about a particular thinker’s idea or presentation. However, as I read Th e Cambridge Companion to Dewey I fi nd that I cannot and should not use the same criteria for evaluation. I pick up a Cambridge Companion when I need an introduction or a refresher on material—not when I need to see what the cutting-edge scholarship is. Th ...

Illusions confuse and bias the machinery in the brain that constructs our representations of the world, because they reveal a discrepancy between what we perceive and what is objectively out there in the world. But both illusions and accurate perceptions are governed by the same lawful perceptual processes. Despite the deceptive simplicity of illusions, there are no fully agreed theories about ...

Unlike most existing work on traversable interfaces, we focus on the use of synthetic characters to accompany the user in Mixed Reality (MR) applications. We examine virtual companions as a promising means to design smooth transitions between different worlds and to avoid orientation problems. We propose a taxonomy to describe the spatial relationship between character and user which has an imp...

Frail older people can normally not be given round-the-clock care-giving assistance. During the time there is no other person around they must be independent. Electronic assistive technology (EAT) can increase an older person's independence in everyday life, but to do so it must be dependable. This paper examines issues of dependability for a special class of EAT software, virtual companions fo...

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We study the model checking problem for logics whose semantics are defined using transitive Kripke models. We show that the model checking problem is P-complete for the intuitionistic logic KC. Interestingly, for its modal companion S4.2 we also obtain P-completeness even if we consider formulas with one variable only. This result is optimal since model checking for S4 without variables is NC-c...

Companion cells represent a major component of the phloem, the plant vascular tissue system responsible for long-distance transport of organic nutrients from the sites of synthesis (source organs) to sites of utilization (sink organs). The companion cells are intimately associated with phloem sieve elements, which make up the actual transport vessel (sieve tube) through which mass flow of assim...