A system of ODEs for a Perturbation of a Minimal Mass Soliton

We study soliton solutions to a nonlinear Schrodinger equation with a saturated nonlinearity. Such nonlinearities are known to possess minimal mass soliton solutions. We consider a small perturbation of a minimal mass soliton, and identify a system of ODEs similar to those from Comech and Pelinovsky (2003), which model the behavior of the perturbation for short times. We then provide numerical evidence that under this system of ODEs there are two possible dynamical outcomes, which is in accord with the conclusions of Pelinovsky, Afanasjev, and Kivshar (1996). For initial data which supports a soliton structure, a generic initial perturbation oscillates around the stable family of solitons. For initial data which is expected to disperse, the finite dimensional dynamics follow the unstable portion of the soliton curve.Comment: Minor edit

Wave instabilities in the presence of non vanishing background in nonlinear Schrodinger systems

We investigate wave collapse ruled by the generalized nonlinear Schroedinger (NLS) equation in 1+1 dimensions, for localized excitations with non-zero background, establishing through virial identities a new criterion for blow-up. When collapse is arrested, a semiclassical approach allows us to show that the system can favor the formation of dispersive shock waves. The general findings are illustrated with a model of interest to both classical and quantum physics (cubic-quintic NLS equation), demonstrating a radically novel scenario of instability, where solitons identify a marginal condition between blow-up and occurrence of shock waves, triggered by arbitrarily small mass perturbations of different sign

Gerardo Patriotta: Organizational Knowledge in the Making: How Firms Create, Use and Institutionalize Knowledge

Book revie

Communities of practice: from innovation in practice to the practice of innovation

Emmanuel Josserand and Florence Villesèche INTRODUCTION In the quest to explain competitive advantage, the knowledge view of the firm appears to be one of the most topical alternatives to transaction costs economics. The ability to share and generate knowledge is thus considered a key capability (Nonaka and Takeuchi, 1995; Nahapiet and Ghoshal, 1998; Merali, 2000). Beyond the initial fads around technology and ITdriven knowledge management projects (Swan et al., 1999), research points to the importance of cultural (McDermott, 1999; Ndlela and du Toit, 2001) and structural change (Grant, 1996; Buckley and Carter, 2002) to favour openness to learning and sharing. This openness is deemed hard to achieve in bureaucratic organizations (Gupta and Govindarajan, 2000; Ravasi and Verona, 2001). How do organizations deal with the apparent contradiction between a necessary order that could lead to bureaucracy and the strategic importance of an innovative openness that could lead to chaos? According to Wenger and Snyder: todays economy runs on knowledge, and most companies work assiduously to capitalize on that fact. They use cross-functional teams, customer- or productfocused business units, and work groups to name just a few organizational forms to capture and spread ideas and know-how. In many cases, these ways of organizing are very effective and no one would argue for their demise. (Wenger and Snyder, 2000, p. 139) However, these forms are usually formal groups often driven by shortterm objectives. Communities of practice (CoPs) a new name for an old practice have been theorized since the early 1990

Penser les pratiques organisationnelles comme des morales avec Michel Foucault

Michel Foucault est lun des auteurs les plus cités dans les articles en management autant par ses supporters que par ses critiques. Plus de 25 ans après sa mort, le 25 juin 1984, et malgré le nombre toujours croissant de publications foucaldiennes en organisation et management, sa pensée est loin dêtre épuisée. Un tour dhorizon de 20 ans de travaux foucaldiens en management nous permettra de répondre à ces trois questions. Pourquoi cet auteur a-t-il été une source dinspiration ou de controverse si grande en sciences de gestion ? Quel est lhéritage quil nous a légué en management ? Sa pensée peut elle encore être mobilisée de façon originale

Orange Brand Launch in France - inside=outside brand transformation

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