How does the attractiveness of a particular option depend on comparisons drawn between it and other alternatives? We observe that in many cases, comparisons hurt: When the options being compared have both meaningful advantages and meaningful disadvantages, comparison between options makes each option less attractive. The effects of comparison are crucial in choice problems involving grouped opt...

Intentionalism is the claim that the phenomenological properties of a perceptual experience supervene on its intentional properties. The paper presents a counterexample to this claim, one that concerns visual grouping phenomenology. I argue that this example is superior to superficially similar examples involving grouping phenomenology offered by Peacocke (1983), because the standard intentiona...

Perceptual grouping is well known to be a fundamental process during visual perception, notably grouping across scenic regions that do not receive contrastive visual inputs. Illusory contours are a classical example of such groupings. Recent psychophysical and neurophysiological evidence have shown that the grouping process can facilitate rapid synchronization of the cells that are bound togeth...

A number of leading theories (e.g., Grossberg & Mingolla, 1985; Kellman & Shipley, 1991; Rensink & Enns, 1995) commonly assume that perceptual grouping by contour alignment occurs preattentively across reversing contrast polarity elements. We examined this notion in seven visual search experiments. We found that only grouping by attachment supported preattentive visual search and that grouping ...

Many time-critical applications require dynamic scheduling with predictable performance. Tasks corresponding to these applications have deadlines to be met despite the presence of faults. In this paper, we propose a technique called dynamic grouping, to be used with backup overloading in a primary-backup based fault-tolerant dynamic scheduling algorithm in multiprocessor real-time systems. In d...

Many time-critical applications require dynamic scheduling with predictable performance. Tasks corresponding to these applications have deadlines to be met despite the presence of faults. In this paper, we propose a technique called dynamic grouping, to be used with backup overloading in a primary-backup based fault-tolerant dynamic scheduling algorithm in multiprocessor real-time systems. In d...

Perceptual grouping is a pre-attentive process which serves to group local elements into global wholes, based on shared properties. One effect of perceptual grouping is to distort the ability to estimate the distance between two elements. In this study, biases in distance estimates, caused by four types of perceptual grouping, were measured across three tasks, a perception, a drawing and a cons...

The concept of grouping in relational algebra is well-known from its connection to aggregation. In this paper we generalize the grouping notion by defining a simultaneous grouping of more than one relation, and we discuss the application of operations on grouping elements other than just arithmetic aggregation. Finally we show that this grouping mechanism can be added to relational algebra with...