6,414 research outputs found
Competing in the Digital Economy?: The Dynamics and Impacts of B2B E-commerce on the South African Manufacturing Sector
ICTs, B2B e-commerce, manufacturing sector, South Africa
Determinants of local responsiveness of FMNCS in mainland China
Recent regulations, associated with Chinaâs accession to the World Trade Organisation (WTO), specifically Decree 113 and Decree 114, have largely changed the situation for foreign multinational construction companies (FMNCs) operating in mainland China. A field investigation has identified that local responsiveness is critical for FMNCs to survive and develop in the complicated and uncertain Chinese construction industry. Government policy, China-specific construction industrial factors and increasing competition intensity imposed by local competitors are recognized as the major determinants driving local responsiveness of FMNCs. This study has also examined that localisation of internal resources, establishment of local networks and cooperation or strategic alliances with local contractors and design institutes are the key local adaptation strategies for FMNCs operating in mainland China
The General Primordial Cosmic Perturbation
We consider the most general primordial cosmological perturbation in a
universe filled with photons, baryons, neutrinos, and a hypothetical cold dark
matter (CDM) component within the framework of linearized perturbation theory.
We give a careful discussion of the different allowed modes, distinguishing
modes which are regular at early times, singular at early times, or pure gauge.
As well as the familiar growing and decaying adiabatic modes and the baryonic
and CDM isocurvature modes we identify two {\it neutrino isocurvature} modes
which do not seem to have been discussed before. In the first, the ratio of
neutrinos to photons varies spatially but the net density perturbation
vanishes. In the second the photon-baryon plasma and the neutrino fluid have a
spatially varying relative bulk velocity, balanced so that the net momentum
density vanishes. Possible mechanisms which could generate the two neutrino
isocurvature modes are discussed. If one allows the most general regular
primordial perturbation, all quadratic correlators of observables such as the
microwave background anisotropy and matter perturbations are completely
determined by a real, symmetric matrix-valued function of
co-moving wavenumber. In a companion paper we examine prospects for detecting
or constraining the amplitudes of the most general allowed regular
perturbations using present and future CMB data.Comment: 18 pages, 2 Postscript figures, uses revtex. Revised 2-2000 Minor
errors corrected and some references adde
Constraining Isocurvature Perturbations with CMB Polarization
The role of cosmic microwave background (CMB) polarisation data in
constraining the presence of primordial isocurvature modes is examined. While
the MAP satellite mission will be unable to simultaneously constrain
isocurvature modes and cosmological parameters, the PLANCK mission will be able
to set strong limits on the presence of isocurvature modes if it makes a
precise measurement of the CMB polarisation sky. We find that if we allow for
the possible presence of isocurvature modes, the recently obtained BOOMERANG
measurement of the curvature of the universe fails. However, a comparably
sensitive polarisation measurement on the same angular scales will permit a
determination of the curvature of the universe without the prior assumption of
adiabaticity.Comment: 4pages, Latex with four eps figures. (Revised 18 Dec 2000. Minor
typos corrected
When does a major outbreak become a Public Health Emergency of International Concern?
The process of determining whether a Public Health Emergencies of International Concern (PHEIC) exists and should be declared has drawn increasing criticism over the past few years with allegations that it is more political than technical. Delaying declaration, where appropriate, means that the opportunity of garnering international solidarity and necessary resources in the early phases of epidemics, when public health measures may be more effective, is lost. A reform agenda aimed at enhancing WHO/Emergency Committee transparency and objectivity for the PHEIC declaration process is required
Observing the Sunyaev-Zel'dovich Effect Closer to Home
Hot gas trapped in a dark matter halo will produce a decrement in the surface
brightness of the microwave background, the Sunyaev-Zel'dovich (SZ) effect.
While massive clusters produce the strongest central SZ decrements, we point
out that a local galaxy halo, specifically the halo of M31, may be one of the
brightest integrated SZ sources in the sky. For various realistic gas
distributions consistent with current X-ray limits, we show that the integrated
SZ decrement from M31 will be comparable to decrements already detected in more
distant sources, provided its halo contains an appreciable quantity of hot gas.
A measurement of this decrement would provide direct information on the mass,
spatial distribution and thermodynamic state of hot gas in a low-mass halo, and
could place important constraints on current models of galaxy formation.
Detecting such an extended (~ 10 degree), low-amplitude signal will be
challenging, but should be possible with all-sky SZ maps from satellite
missions such as the Wilkinson Microwave Anisotropy Probe or the Planck
Surveyor.Comment: 5 pages, 3 figures; submitted to MNRA
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