4,365 research outputs found
Entrepreneurial value creation: conceptualizing an exchange-based view of entrepreneurship
4sìopenPurpose: This paper proposes an Exchange-Based View of the value creation process. The Borrowing from marketing literature, the EBV advances that entrepreneurs and stakeholders are tied by exchange relationships, through which they co-create value by reciprocally making and realizing promises of value. Design/methodology/approach: Propositions are developed and offered to advance the role of exchange in the entrepreneurial value creation process. Findings: The authors conceptualize the enterprise as a system of exchange relationships between entrepreneurs and their stakeholders, thus proposing an exchange-based view of entrepreneurship. Originality/value: Such an account of the role of entrepreneurs and of their relationship with the stakeholders has meaningful implications for our understanding of the entrepreneurial tasks of opportunity recognition and exploitation.openPinelli M.; Lechner C.; Kraus S.; Liguori E.Pinelli, M.; Lechner, C.; Kraus, S.; Liguori, E
An operator expansion for integrable quantum field theories
A large class of quantum field theories on 1+1 dimensional Minkowski space,
namely, certain integrable models, has recently been constructed rigorously by
Lechner. However, the construction is very abstract and the concrete form of
local observables in these models remains largely unknown. Aiming for more
insight into their structure, we establish a series expansion for observables,
similar but not identical to the well-known form factor expansion. This
expansion will be the basis for a characterization and explicit construction of
local observables, to be discussed elsewhere. Here, we establish the expansion
independent of the localization aspect, and analyze its behavior under
space-time symmetries. We also clarify relations with deformation methods in
quantum field theory, specifically, with the warped convolution in the sense of
Buchholz and Summers.Comment: minor corrections and clarifications, as published in J. Phys A; 24
page
SU(2) Cosmological Solitons
We present a class of numerical solutions to the SU(2) nonlinear
-model coupled to the Einstein equations with cosmological constant
in spherical symmetry. These solutions are characterized by the
presence of a regular static region which includes a center of symmetry. They
are parameterized by a dimensionless ``coupling constant'' , the sign of
the cosmological constant, and an integer ``excitation number'' . The
phenomenology we find is compared to the corresponding solutions found for the
Einstein-Yang-Mills (EYM) equations with positive (EYM). If
we choose positive and fix , we find a family of static spacetimes
with a Killing horizon for . As a limiting solution
for we find a {\em globally} static spacetime with
, the lowest excitation being the Einstein static universe. To
interpret the physical significance of the Killing horizon in the cosmological
context, we apply the concept of a trapping horizon as formulated by Hayward.
For small values of an asymptotically de Sitter dynamic region contains
the static region within a Killing horizon of cosmological type. For strong
coupling the static region contains an ``eternal cosmological black hole''.Comment: 20 pages, 6 figures, Revte
Gaining Insight into Determinants of Physical Activity using Bayesian Network Learning
Contains fulltext :
228326pre.pdf (preprint version ) (Open Access)
Contains fulltext :
228326pub.pdf (publisher's version ) (Open Access)BNAIC/BeneLearn 202
Optical Spectroscopy of IRAS 02091+6333
We present a detailed spectroscopic investigation, spanning four winters, of
the asymptotic giant branch (AGB) star IRAS 02091+6333. Zijlstra & Weinberger
(2002) found a giant wall of dust around this star and modelled this unique
phenomenon. However their work suffered from the quality of the optical
investigations of the central object. Our spectroscopic investigation allowed
us to define the spectral type and the interstellar foreground extinction more
precisely. Accurate multi band photometry was carried out. This provides us
with the possibility to derive the physical parameters of the system. The
measurements presented here suggest a weak irregular photometric variability of
the target, while there is no evidence of a spectroscopic variability over the
last four years.Comment: 5 pages, Latex, 3 tables, 4 figures, Astron. & Astrophys. - in pres
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