1,239 research outputs found
Order and disorder in product innovation models
This article argues that the conceptual development of product innovation models goes hand in hand with paradigmatic changes in the field of organization science. Remarkable similarities in the change of organizational perspectives and product innovation models are noticeable. To illustrate how changes in the organizational paradigm are being translated into changes in new product development (NPD) practices, five NPD models are presented: the sequential, compression, flexible, integrative and improvisational models. The evolution of product innovation management shows a move from planned and mechanistic, towards emergent and organic models. Such a process of re-orientation poses several challenges that are presented in the form of six propositions: from universal to contingent models, from invariant to flexible practices, from avoiding risks to taking advantage of opportunities, from planning to learning, from exclusive teams to inclusive networks, from structure to structured chaos
Dyonic Integrable Models
A class of non abelian affine Toda models arising from the axial gauged
two-loop WZW model is presented. Their zero curvature representation is
constructed in terms of a graded Kac-Moody algebra. It is shown that the
discrete multivacua structure of the potential together with non abelian nature
of the zero grade subalgebra allows soliton solutions with non trivial electric
and topological charges.
The dressing transformation is employed to explicitly construct one and two
soliton solutions and their bound states in terms of the tau functions. A
discussion of the classical spectra of such solutions and the time delays are
given in detail.Comment: Latex 30 pages, corrected some typo
Integrable Field Theories with Defects
The structure of integrable field theories in the presence of defects is
discussed in terms of boundary functions under the Lagrangian formalism.
Explicit examples of bosonic and fermionic theories are considered. In
particular, the boundary functions for the super sinh-Gordon model is
constructed and shown to generate the Backlund transformations for its soliton
solutions.Comment: talk presented at the XVth International Colloquium on Integrable
Systems and Quantum Symmetries, to appear in Czechoslovak Journal of Physics
(2006
Preface to the special issue âCommemorative contributions for the 30 years of the Catalysis and Porous Materials Division of the Portuguese Chemical Society (SPQ)â
More than thirty years have passed since the beginning of the Division
of Catalysis of the Portuguese Chemical Society (SPQ), in 2001
expanded to Division of Catalysis and Porous Materials, in order to
reflect the application of porous materials in non-catalytic processes,
such as adsorption. We are commemorating this milestone in the
Chemistry field in Portugal and, to honor the History behind its creation,
consolidation and continuous challenges, we projected this Special
Issue, entitled âCommemorative contributions for the 30 years of the
Catalysis and Porous Materials Division of the Portuguese Chemical
Society (SPQ)â.info:eu-repo/semantics/publishedVersio
T-duality of axial and vector dyonic integrable models
A general construction of affine Non Abelian (NA) - Toda models in terms of
axial and vector gauged two loop WZNW model is discussed. They represent {\it
integrable perturbations} of the conformal -models (with tachyons
included) describing (charged) black hole type string backgrounds. We study the
{\it off-critical} T-duality between certain families of axial and vector type
of integrable models for the case of affine NA- Toda theories with one global
U(1) symmetry. In particular we find the Lie algebraic condition defining a
subclass of {\it T-selfdual} torsionless NA Toda models and their zero
curvature representation.Comment: 20 pages, latex, no figures,improvments in the text of Sects.1,2 and
6;typos corrected,references added, to appear in Ann. of Physics (NY
Higher Grading Conformal Affine Toda Teory and (Generalized) Sine-Gordon/Massive Thirring Duality
Some properties of the higher grading integrable generalizations of the
conformal affine Toda systems are studied. The fields associated to the
non-zero grade generators are Dirac spinors. The effective action is written in
terms of the Wess-Zumino-Novikov-Witten (WZNW) action associated to an affine
Lie algebra, and an off-critical theory is obtained as the result of the
spontaneous breakdown of the conformal symmetry. Moreover, the off-critical
theory presents a remarkable equivalence between the Noether and topological
currents of the model. Related to the off-critical model we define a real and
local Lagrangian provided some reality conditions are imposed on the fields of
the model. This real action model is expected to describe the soliton sector of
the original model, and turns out to be the master action from which we uncover
the weak-strong phases described by (generalized) massive Thirring and
sine-Gordon type models, respectively. The case of any (untwisted) affine Lie
algebra furnished with the principal gradation is studied in some detail.
The example of is presented explicitly.Comment: 28 pages, JHEP styl
Operator Formulation of q-Deformed Dual String Model
We present an operator formulation of the q-deformed dual string model
amplitude using an infinite set of q-harmonic oscillators. The formalism
attains the crossing symmetry and factorization and allows to express the
general n-point function as a factorized product of vertices and propagators.Comment: 6pages, Late
Toda and Volterra Lattice Equations from Discrete Symmetries of KP Hierarchies
The discrete models of the Toda and Volterra chains are being constructed out
of the continuum two-boson KP hierarchies. The main tool is the discrete
symmetry preserving the Hamiltonian structure of the continuum models. The
two-boson currents of KP hierarchy are being associated with sites of the
corresponding chain by successive actions of discrete symmetry.Comment: 12 pgs, LaTeX, IFT-P.041/9
A symmetry reduction technique for higher order Painlev\'e systems
The symmetry reduction of higher order Painlev\'e systems is formulated in
terms of Dirac procedure.
A set of canonical variables that admit Dirac reduction procedure is proposed
for Hamiltonian structures governing the and
Painlev\'e systems for .Comment: to appear in Phys. Lett.
Some comments on the bi(tri)-Hamiltonian structure of Generalized AKNS and DNLS hierarchies
We give the correct prescriptions for the terms involving the inverse of the
derivative of the delta function, in the Hamiltonian structures of the AKNS and
DNLS systems, in order for the Jacobi identities to hold. We also establish
that the sl(2) AKNS and DNLS systems are tri-Hamiltonians and construct two
compatible Hamiltonian structures for the sl(3) AKNS system. We also give a
derivation of the recursion operator for the sl(n+1) DNLS system.Comment: 10 pages, LaTe
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