— Kaup-Newell soliton hierarchy is derived from a kind of Lax pairs different from the original ones. Binary nonlinearization procedure corresponding to the Bargmann symmetry constraint is carried out for those Lax pairs. The proposed Lax pairs together with adjoint Lax pairs are constrained as a hierarchy of commutative, finite dimensional integrable Hamiltonian systems in the Liouville sense,...

* Gerarden: Harvard Kennedy School, 79 John F. Kennedy St., Cambridge, MA 02138 (e-mail: [email protected]); Newell: Nicholas School of the Environment, Duke University, 140 Science Dr., 101 Gross Hall, Durham, NC 27708 (email: [email protected]); Stavins: Harvard Kennedy School, 79 John F. Kennedy St., Cambridge, MA 02138 (e-mail: [email protected]). This paper draws in p...

One major limitation of current cognitive architectures is that models are typically constructed in an "empty" architecture, and that the knowledge specifications (typically production rules) are specific to the particular task. This means that general executive control strategies have to be implemented for each specific model, which means a lack of consistency and constraint. Alternatively, th...

Allen Newell (1973) once observed that psychology researchers were playing "twenty questions with nature," carving up human cognition into hundreds of individual phenomena but shying away from the difficult task of integrating these phenomena with unifying theories. We argue that research on cognitive control has followed a similar path, and that the best approach toward unifying theories of co...

In a Perspective, Collins Iwuji and Marie-Louise Newell discuss early findings from Richard Hayes and colleagues' PopART study on HIV testing and treatment.