57,824 research outputs found
Firm and industry effects in accounting versus economic profit data
This article presents estimates of firm and industry fixed-effects on profit rates for large US corporations, using both Economic Value Added (EVA), the popular measure of profits produced by Stern Stewart and Company, as well as simple (unadjusted) accounting measures as the dependent variable. We find that the improvement in explanatory power of the fixed-effect model is substantially greater when using EVA than has been documented with alternative measures
The Persistence of Accounting versus Economic Profit
Drawing on Schumpeterian theory, this article presents estimates of a first-order autoregressive model of profit persistence for large US firms, using Economic Value Added (EVA), the popular measure of profits produced by Stern Stewart and Company, and simple (unadjusted) accounting measures from the Compustat database. We hypothesize about the differences we should expect to find between these two sets of estimates, and also provide a fresh normative assessment of the dynamic competitiveness of the US economy
Relaxed Three-Algebras: Their Matrix Representations and Implications for Multi M2-brane Theory
We argue that one can relax the requirements of the non-associative
three-algebras recently used in constructing D=3, N=8 superconformal field
theories, and introduce the notion of ``relaxed three-algebras''. We present a
specific realization of the relaxed three-algebras in terms of classical Lie
algebras with a matrix representation, endowed with a non-associative
four-bracket structure which is prescribed to replace the three-brackets of the
three-algebras. We show that both the so(4)-based solutions as well as the
cases with non-positive definite metric find a uniform description in our
setting. We discuss the implications of our four-bracket representation for the
D=3, N=8 and multi M2-brane theory and show that our setup can shed light on
the problem of negative kinetic energy degrees of freedom of the Lorentzian
case.Comment: 31 pages, no figure
Directive emission of red conjugated polymer embedded within zero index metamaterials
Abstract: We numerically demonstrate an impedance-matched multilayer stacked fishnet metamaterial that has zero index with flat high transmittance from 600nm to 620nm. The effective refractive index
Polymer packaging and ejection in viral capsids: shape matters
We use a mesoscale simulation approach to explore the impact of different
capsid geometries on the packaging and ejection dynamics of polymers of
different flexibility. We find that both packing and ejection times are faster
for flexible polymers. For such polymers a sphere packs more quickly and ejects
more slowly than an ellipsoid. For semiflexible polymers, however, the case
relevant to DNA, a sphere both packs and ejects more easily. We interpret our
results by considering both the thermodynamics and the relaxational dynamics of
the polymers. The predictions could be tested with bio-mimetic experiments with
synthetic polymers inside artificial vesicles. Our results suggest that phages
may have evolved to be roughly spherical in shape to optimise the speed of
genome ejection, which is the first stage in infection.Comment: 4 pages, 4 figure
The measured compositions of Uranus and Neptune from their formation on the CO iceline
The formation mechanisms of the ice giants Uranus and Neptune, and the origin
of their elemental and isotopic compositions, have long been debated. The
density of solids in the outer protosolar nebula is too low to explain their
formation, and spectroscopic observations show that both planets are highly
enriched in carbon, very poor in nitrogen, and the ices from which they
originally formed might had deuterium-to-hydrogen ratios lower than the
predicted cometary value, unexplained properties observed in no other planets.
Here we show that all these properties can be explained naturally if Uranus and
Neptune both formed at the carbon monoxide iceline. Due to the diffusive
redistribution of vapors, this outer region of the protosolar nebula
intrinsically has enough surface density to form both planets from carbon-rich
solids but nitrogen-depleted gas, in abundances consistent with their observed
values. Water rich interiors originating mostly from transformed CO ices
reconcile the D/H value of Uranus and Neptune's building blocks with the
cometary value. Finally, Our scenario generalizes a well known hypothesis that
Jupiter formed on an iceline (water snowline) for the two ice giants, and might
be a first step towards generalizing this mechanism for other giant planets.Comment: The Astrophysical Journal (in press), 8 pages, 5 figure
Fermions in non-relativistic AdS/CFT correspondence
We extend the non-relativistic AdS/CFT correspondence to the fermionic
fields. In particular we study the two point function of a fermionic operator
in non-relativistic CFTs by making use of a massive fermion propagating in
geometries with Schrodinger group isometry. Although the boundary of the
geometries with Schrodinger group isometry differ from that in AdS geometries
where the dictionary of AdS/CFT is established, using the general procedure of
AdS/CFT correspondence, we see that the resultant two point function has the
expected form for fermionic operators in non-relativistic CFTs, though a
non-trivial regularization may be needed.Comment: 12 pages,Latex file; V2: typos corrected, refs adde
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The role of structural embeddedness in an IT outsourcing network
The design of governance to safeguard against a vendor's opportunistic behaviour is one of the critical issues in information technology outsourcing (ITO) since this behaviour causes cost escalation and service debasement. The roles of structural embeddedness underlying network governance have been gaining its importance as complementary or substitutable governance in ITO. Our research attempts to reveal how structural embeddedness can affect the decision-makings of clients and vendors and their resulting outcomes in an ITO network and how these effects are moderated by various ITO network structures according to outsourced IT services. An agent-based simulation and game-theoretic approach are adopted to build a simulation model to describe ITO networks with various structures and ITO transactions between clients and vendors. Finally, the future research directions are discussed
The persistence of accounting versus economic profit
Drawing on Schumpeterian theory, this article presents estimates of a first-order autoregressive model of profit persistence for large US firms, using Economic Value Added (EVA), the popular measure of profits produced by Stern Stewart and Company, and simple (unadjusted) accounting measures from the Compustat database. We hypothesize about the differences we should expect to find between these two sets of estimates, and also provide a fresh normative assessment of the dynamic competitiveness of the US economy.dynamic competition efficiency persistence
Submm-bright QSOs at z~2: signposts of co-evolution at high z
We have assembled a sample of 5 X-ray and submm-luminous z~2 QSOs which are
therefore both growing their central black holes through accretion and forming
stars copiously at a critical epoch. Hence, they are good laboratories to
investigate the co-evolution of star formation and AGN. We have performed a
preliminary analysis of the AGN and SF contributions to their UV-to-FIR SEDs,
fitting them with simple direct (disk), reprocessed (torus) and star formation
components. All three are required by the data and hence we confirm that these
objects are undergoing strong star formation in their host galaxies at rates
500-2000 Msun/y. Estimates of their covering factors are between about 30 and
90%. In the future, we will assess the dependence of these results on the
particular models used for the components and relate their observed properties
to the intrinsice of the central engine and the SF material, as well as their
relevance for AGN-galaxy coevolution.Comment: 6 pages, 2 figures, contributed talk to "Nuclei of Seyfert galaxies
and QSOs - Central engine & conditions of star formation" November 6-8, 2012.
MPIfR, Bonn, Germany. Po
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