First we develop the theory of reduced instability in order to analyze stability of bifurcating solutions via the Liapunov{Schmidt reduction. Next, this theory is generalized to cover sideband instabilities using a Floquet ansatz. The method is applied to roll patterns in the Swift{Hohenberg equation which serves as a model for pattern formation. We analyze the stability problem of small rolls ...

Vision should provide an explanation of the scene in terms of a causal semantics|what aaects what, and why. An important part of the causal explanation of static scenes is what supports what, or, counterfactu-ally: Why aren't things moving? We use simple naive physical knowledge as the basis of a vertically integrated vision system that explains arbitrarily complex stacked block structures. The...

Number-knower levels are a series of stages of number concept development in early childhood. A child's number-knower level is typically assessed using the give-N task. Although the task procedure has been highly refined, the standard ways of analyzing give-N data remain somewhat crude. Lee and Sarnecka (Cogn Sci 34:51-67, 2010, in press) have developed a Bayesian model of children's performanc...

In this paper we present a model of the multiple unit, single item procurement network formation problem in environments with incomplete information (MPNFI). For this we first develop the structure of the procurement network formation problem within Myerson’s framework for cooperative games with incomplete information [1]. Using this framework we then investigate the non-emptiness of the incent...

BACKGROUND A cryptosporidiosis epidemic occurred among residents and visitors to Collingwood, Ontario, during March 1996. Fifty-five per cent of 36 confirmed cases were Collingwood visitors and 57% of Collingwood resident cases were under 10 years of age. The low level of reported diarrhoeal illness among adult Collingwood residents caused government officials and physicians to question whether...

We study the control of modulational instability and pattern formation in a nonlinear dissipative feedback system with a periodic modulation of the material refractive index. We use a one-dimensional photonic lattice in a single-mirror feedback configuration and identify three mechanisms for pattern control: bandgap suppression of instability modes, periodicity induced pattern modes, and orient...

In 1990, one of us (Jackson) offered a hypothesis as an attempt to explain simultaneously all observations regarding the Shroud image (Ref 1). This hypothesis was ventured only after a systematic study of alternatives had failed to account for various image characteristics (Ref 2) and, though unconventional, this hypothesis makes a variety of testable predictions that are a-priori falsifiable b...

We present some numerical results obtained from a simple individual-based model that describes clustering of organisms caused by competition. Our aim is to show that, even when a deterministic description developed for continuum models predicts no pattern formation, an individual-based model displays well-defined patterns, as a consequence of fluctuation effects caused by the discrete nature of...

Cooperators that refuse to participate in sanctioning defectors create the second-order free-rider problem. Such cooperators will not be punished because they contribute to the public good, but they also eschew the costs associated with punishing defectors. Altruistic punishers — those that cooperate and punish — are at a disadvantage, and it is puzzling how such behaviour has evolved. We show ...