5,275 research outputs found
History of marketing thought : an update / BEBR No. 857
Includes bibliographical references (p. 21-26)
An earnings-return model for strategic market planning / BEBR No. 869
Includes bibliographical references (p. 38-39).Few models currently exist which aid managers in their strategic market planning. The models or frameworks which do exist have a variety of shortcomings, a major one being an inadequate linkage to a business organization's dominant goals for existence -- earnings and return on investment. This paper develops a planning model based on a firm's present levels of earnings and return designed to provide a partial foundation on which its managers can base their strategic market planning. Depending upon the firm's placement in the model, different organizational objectives and strategies exist for improving future performance
Secular Evolution Via Bar-Driven Gas Inflow: Results from BIMA SONG
We present an analysis of the molecular gas distributions in the 29 barred
and 15 unbarred spirals in BIMA SONG. For CO-bright galaxies, we confirm the
conclusion by Sakamoto et al. (1999b) that barred spirals have higher molecular
gas concentrations in the central kiloparsec. The SONG sample also includes 27
galaxies below the CO brightness limit used by Sakamoto et al. Even in these
CO-faint galaxies we show that high central gas concentrations are more common
in barred galaxies, consistent with radial inflow driven by the bar. However,
there is a significant population of early-type (Sa--Sbc) barred spirals (6 of
19) that have little or no molecular gas detected in the nuclear region and out
to the bar co-rotation radius. In these galaxies, the bar has already driven
most of the gas within the bar to the nuclear region, where it has been
consumed by star formation. The median nuclear gas mass is over four times
higher in early type bars; since the gas consumption rate is an order of
magnitude higher in early type bars, early types must have significantly higher
bar-driven inflows. The lower inflow rates in late type bars can be attributed
to differences in bar structure between early and late types. Despite
bar-driven inflows, the data indicate that it is highly unlikely for a late
type galaxy to evolve into an early type via bar-induced gas inflow.
Nonetheless, secular evolutionary processes are undoubtedly present, and
pseudo-bulges are inevitable; evidence for pseudo-bulges is likely to be
clearest in early-type galaxies because of their high gas inflow rates and
higher star formation activity (abridged).Comment: Accepted for publication in The Astrophysical Journa
Nonlinear Velocity-Density Coupling: Analysis by Second-Order Perturbation Theory
Cosmological linear perturbation theory predicts that the peculiar velocity
and the matter overdensity at a same point are
statistically independent quantities, as log as the initial density
fluctuations are random Gaussian distributed. However nonlinear gravitational
effects might change the situation. Using framework of second-order
perturbation theory and the Edgeworth expansion method, we study local density
dependence of bulk velocity dispersion that is coarse-grained at a weakly
nonlinear scale. For a typical CDM model, the first nonlinear correction of
this constrained bulk velocity dispersion amounts to (Gaussian
smoothing) at a weakly nonlinear scale with a very weak dependence on
cosmological parameters. We also compare our analytical prediction with
published numerical results given at nonlinear regimes.Comment: 16 pages including 2 figures, ApJ 537 in press (July 1
Unbiased estimates of galaxy scaling relations from photometric redshift surveys
Many physical properties of galaxies correlate with one another, and these
correlations are often used to constrain galaxy formation models. Such
correlations include the color-magnitude relation, the luminosity-size
relation, the Fundamental Plane, etc. However, the transformation from
observable (e.g. angular size, apparent brightness) to physical quantity
(physical size, luminosity), is often distance-dependent. Noise in the distance
estimate will lead to biased estimates of these correlations, thus compromising
the ability of photometric redshift surveys to constrain galaxy formation
models. We describe two methods which can remove this bias. One is a
generalization of the V_max method, and the other is a maximum likelihood
approach. We illustrate their effectiveness by studying the size-luminosity
relation in a mock catalog, although both methods can be applied to other
scaling relations as well. We show that if one simply uses photometric
redshifts one obtains a biased relation; our methods correct for this bias and
recover the true relation
Comparative Analysis of Molecular Clouds in M31, M33 and the Milky Way
We present BIMA observations of a 2\arcmin field in the northeastern spiral
arm of M31. In this region we find six giant molecular clouds that have a mean
diameter of 5713 pc, a mean velocity width of 6.51.2 \kms, and a mean
molecular mass of 3.0 1.6 10\Msun. The peak brightness
temperature of these clouds ranges from 1.6--4.2 K. We compare these clouds to
clouds in M33 observed by \citet{wilson90} using the OVRO millimeter array, and
some cloud complexes in the Milky Way observed by \cite{dame01} using the CfA
1.2m telescope. In order to properly compare the single dish data to the
spatially filtered interferometric data, we project several well-known Milky
Way complexes to the distance of Andromeda and simulate their observation with
the BIMA interferometer. We compare the simulated Milky Way clouds with the M31
and M33 data using the same cloud identification and analysis technique and
find no significant differences in the cloud properties in all three galaxies.
Thus we conclude that previous claims of differences in the molecular cloud
properties between these galaxies may have been due to differences in the
choice of cloud identification techniques. With the upcoming CARMA array,
individual molecular clouds may be studied in a variety of nearby galaxies.
With ALMA, comprehensive GMC studies will be feasible at least as far as the
Virgo cluster. With these data, comparative studies of molecular clouds across
galactic disks of all types and between different galaxy disks will be
possible. Our results emphasize that interferometric observations combined with
the use of a consistent cloud identification and analysis technique will be
essential for such forthcoming studies that will compare GMCs in the Local
Group galaxies to galaxies in the Virgo cluster.Comment: Accepted for Publication in the Astrophysical Journa
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