144 research outputs found
Integrating business-to-business customers in original equipment manufacturersâ supply chains through information systems integration
Original equipment manufacturers (OEMs) are increasingly being urged to integrate their business-to-business customers into their supply chain. This involves integrating the information systems of the OEMâs supply chain with those of the customers. However, the literature has little to say about what it takes to integrate the information systems of OEMsâ supply chain and business customers. This paper develops a framework that identifies different levels of integration of business customersâ information systems with those of the OEMâs supply chain. It then discusses how this integration affects market performance and strategic gains that accrue to the chain. However, if such systems are integrated without appropriate conditions within and outside the OEMâs supply chain, it may not be possible to actualise the potential of such integration. Therefore, we also identify and examine how a variety of contextual factors moderate the effectiveness of customersâ systems integration in a supply chain.info:eu-repo/semantics/publishedVersio
A Model for Using the Internet and the Web Technologies for New Product Development
Recent developments in Internet technology and the World Wide Web have the potential of making the product development process truly integrated, simultaneous, flexible, and responsive. However, little is known about how the Web can be effectively used for new product development. Based on the premise that Internet technology can be an agent of enterprise information integration, information enabled organization, and customer responsiveness, we develop a reference model which lays out the scope and benefits of using the Web for new product development. We also develop an implementation framework that informs product development managers about a variety of Web technologies that can be used for Web-based product development
Duality and Non-Commutative Gauge Theory
We study the generalization of S-duality to non-commutative gauge theories.
For rank one theories, we obtain the leading terms of the dual theory by
Legendre transforming the Lagrangian of the non-commutative theory expressed in
terms of a commutative gauge field. The dual description is weakly coupled when
the original theory is strongly coupled if we appropriately scale the
non-commutativity parameter. However, the dual theory appears to be
non-commutative in space-time when the original theory is non-commutative in
space. This suggests that locality in time for non-commutative theories is an
artifact of perturbation theory.Comment: 7 pages, harvmac; a typo fixe
Pinned Branes and New Non Lorentz Invariant Theories
We describe a mechanism for localising branes in ambient space. When a 3-form
flux is turned on in a Taub-NUT space, an M5-brane gets an effective potential
that pins it to the center of the space. A similar effect occurs for M2-branes
and D-branes with appropriate fluxes. In carefully chosen limits of the
external parameters, this leads to new theories that are decoupled from gravity
and appear to break Lorentz invariance. For example, we predict the existence
of a new 5+1D theory that breaks Lorentz invariance at high-energy and has a
low-energy description of N tensor multiplets with (1,0) supersymmetry. We also
predict a new type of theory that, similarly to the little-string theory
decouples from gravity by a dynamical (rather than kinematical) argument.Comment: 29pp LaTeX, formulas in section 7 corrected, ref added, final version
to appear in Nucl. Phys.
Tangled magnetic fields and CMBR signal from reionization epoch
We compute the secondary CMBR anisotropy signal from the reionization of the
universe in the presence of tangled magnetic fields. We consider the tangled
magnetic-field-induced scalar, vector, and tensor modes for our analysis. The
most interesting signal for l<10 arise from tensor perturbations. In
particular, we show that the enhancement observed by WMAP in the TE
cross-correlation signal for l<10 could be explained by tensor TE
cross-correlation from tangled magnetic fields generated during the
inflationary epoch for magnetic field strength B_0=4.5*10^{-9}G and magnetic
field power spectrum spectral index n=-2.9. Alternatively, a mixture of tensor
mode signal with primordial scalar modes give weaker bounds on the value of the
optical depth to the reionization surface, tau_{reion}=0.11 +/- 0.02. This
analysis can also be translated to a limit on the magnetic field strength of
nearly 5*10{-9}G for wave-numbers < 0.05 Mpc^{-1}Comment: 28 pages, 6 figures, submitted to Physical Review
Time-Dependent Warping, Fluxes, and NCYM
We describe the supergravity solutions dual to D6-branes with both
time-dependent and time-independent B-fields. These backgrounds generalize the
Taub-NUT metric in two key ways: they have asymmetric warp factors and
background fluxes. In the time-dependent case, the warping takes a novel form.
Kaluza-Klein reduction in these backgrounds is unusual, and we explore some of
the new features. In particular, we describe how a localized gauge-field
emerges with an analogue of the open string metric and coupling. We also
describe a gravitational analogue of the Seiberg-Witten map. This provides a
framework in supergravity both for studying non-commutative gauge theories, and
for constructing novel warped backgrounds.Comment: 32 pages, LaTeX, references adde
Duality in Heterotic Vacua With Four Supercharges
We study heterotic vacua with four supercharges in three and four space-time
dimensions and their duals obtained as M/F-theory compactified on Calabi-Yau
fourfolds. We focus on their respective moduli spaces and derive the Kahler
potential for heterotic vacua obtained as circle compactifications of
four-dimensional N=1 heterotic theories. The Kahler potential of the dual
theory is computed by compactifying 11-dimensional supergravity on Calabi-Yau
fourfolds. The duality between these theories is checked for K3-fibred
fourfolds and an appropriate F-theory limit is discussed.Comment: 28 pages, LaTe
Five-Brane Superpotentials and Heterotic/F-theory Duality
Under heterotic/F-theory duality it was argued that a wide class of heterotic
five-branes is mapped into the geometry of an F-theory compactification
manifold. In four-dimensional compactifications this identifies a five-brane
wrapped on a curve in the base of an elliptically fibered Calabi-Yau threefold
with a specific F-theory Calabi-Yau fourfold containing the blow-up of the
five-brane curve. We argue that this duality can be reformulated by first
constructing a non-Calabi-Yau heterotic threefold by blowing up the curve of
the five-brane into a divisor with five-brane flux. Employing
heterotic/F-theory duality this leads us to the construction of a Calabi-Yau
fourfold and four-form flux. Moreover, we obtain an explicit map between the
five-brane superpotential and an F-theory flux superpotential. The map of the
open-closed deformation problem of a five-brane in a compact Calabi-Yau
threefold into a deformation problem of complex structures on a dual Calabi-Yau
fourfold with four-form flux provides a powerful tool to explicitly compute the
five-brane superpotential.Comment: 43 pages, v2: minor correction
Proton Decay, Yukawa Couplings and Underlying Gauge Symmetry in String Theory
In string theory, massless particles often originate from a symmetry breaking
of a large gauge symmetry G to its subgroup H. The absence of dimension-4
proton decay in supersymmetric theories suggests that (\bar{D},L) are different
from \bar{H}(\bar{\bf 5}) in their origins. In this article, we consider a
possibility that they come from different irreducible components in
. Requiring that all the Yukawa coupling constants
of quarks and leptons be generated from the super Yang--Mills interactions of
G, we found in the context of Georgi--Glashow H=SU(5) unification that the
minimal choice of G is E_7 and E_8 is the only alternative. This idea is
systematically implemented in Heterotic String, M theory and F theory,
confirming the absence of dimension 4 proton decay operators. Not only H=SU(5)
but also G constrain operators of effective field theories, providing
non-trivial information.Comment: 73 page
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