9,570 research outputs found
Financing asset growth : [version 11 august 2013]
In this paper we provide new evidence that corporate financing decisions are associated with managerial incentives to report high equity earnings. Managers rely most heavily on debt to finance their asset growth when their future earnings prospects are poor, when they are under pressure due to past declines in earnings, negative past stock returns, and excessively optimistic analyst earnings forecasts, and when the earnings yield is high relative to bond yields so that from an accounting perspective equity is ‘expensive’. Managers of high debt issuing firms are more likely to be newly appointed and also more likely to be replaced in subsequent years. Abnormal returns on portfolios formed on the basis of asset growth and debt issuance are strongly positively associated with the contemporaneous changes in returns on assets and on equity as well as with earnings surprises. This may account for the finding that debt issuance forecasts negative abnormal returns, since debt issuance also forecasts negative changes in returns on assets and on equity and negative earnings surprises. Different mechanisms appear to be at work for firms that retire debt
Variable Bandwidth Filter for Multibeam Echo-sounding Bottom Detection
The accuracy of a seafloor map derived from multibeam swath bathymetry depends first and foremost on the quality of the bottom detection process that yields estimates of the arrival time and angle of bottom echoes received in each beam. Filtering of each beam with a fixed bandwidth filter, with the bandwidth based on the length of the transmitted pulse, reduces the error associated with the time-angle estimates. However, filters of this type can not be optimal over the wide range of operational environments encountered. Better results are obtained with a processing scheme that varies the filter bandwidth across the swath width using detected time and angle information from the previous ping. This method is evaluated using sonar data obtained with a Reson SeaBat 8111ER and the results compared with those obtained using a fixed bandwidth filter
Automated tracking of colloidal clusters with sub-pixel accuracy and precision
Quantitative tracking of features from video images is a basic technique
employed in many areas of science. Here, we present a method for the tracking
of features that partially overlap, in order to be able to track so-called
colloidal molecules. Our approach implements two improvements into existing
particle tracking algorithms. Firstly, we use the history of previously
identified feature locations to successfully find their positions in
consecutive frames. Secondly, we present a framework for non-linear
least-squares fitting to summed radial model functions and analyze the accuracy
(bias) and precision (random error) of the method on artificial data. We find
that our tracking algorithm correctly identifies overlapping features with an
accuracy below 0.2% of the feature radius and a precision of 0.1 to 0.01 pixels
for a typical image of a colloidal cluster. Finally, we use our method to
extract the three-dimensional diffusion tensor from the Brownian motion of
colloidal dimers.Comment: 20 pages, 8 figures. Non-revised preprint version, please refer to
http://dx.doi.org/10.1088/1361-648X/29/4/04400
Spatially resolved photo ionization of ultracold atoms on an atom chip
We report on photo ionization of ultracold magnetically trapped Rb atoms on
an atom chip. The atoms are trapped at 5 K in a strongly anisotropic
trap. Through a hole in the chip with a diameter of 150 m two laser beams
are focussed onto a fraction of the atomic cloud. A first laser beam with a
wavelength of 778 nm excites the atoms via a two photon transition to the 5D
level. With a fiber laser at 1080 nm the excited atoms are photo ionized.
Ionization leads to depletion of the atomic density distribution observed by
absorption imaging. The resonant ionization spectrum is reported. The setup
used in this experiment is not only suitable to investigate BEC ion mixtures
but also single atom detection on an atom chip
Aerobee 150 structural and aerodynamic pitch coupling
Aerobee 150 structural and aerodynamic pitch coupling failure analysis based on flight performance data reductio
Measurement of In Situ Acoustic Properties for the ONR Geoclutter Program, Annual Report, Geoclutter Program
Mating Flights of \u3ci\u3eEphoron Album\u3c/i\u3e (Ephemeroptera: Polymitarcidae) in Michigan
Mating flights of the mayfly Ephoron album (Say) were observed on the Sturgeon River in Houghton County, Michigan, on five evenings between 16 and 22 August, 1977. Peak emergence occurred about 30 minutes befqre sunset on 19 August and the flight period lasted about two hours. Many more adult males than females were collected on three evenings, but on one evening females greatly outnumbered males collected
Microparticle assembly pathways on lipid membranes
Understanding interactions between microparticles and lipid membranes is of
increasing importance, especially for unraveling the influence of microplastics
on our health and environment. Here, we study how a short-ranged adhesive force
between microparticles and model lipid membranes causes membrane-mediated
particle assembly. Using confocal microscopy, we observe the initial particle
attachment to the membrane, then particle wrapping, and in rare cases
spontaneous membrane tubulation. In the attached state, we measure that the
particle mobility decreases by 26%. If multiple particles adhere to the same
vesicle, their initial single-particle state determines their interactions and
subsequent assembly pathways: 1) attached particles only aggregate when small
adhesive vesicles are present in solution, 2) wrapped particles reversibly
attract one another by membrane deformation, and 3) a combination of wrapped
and attached particles form membrane-mediated dimers, which further assemble
into a variety of complex structures. The experimental observation of distinct
assembly pathways induced only by a short ranged membrane-particle adhesion,
shows that a cellular cytoskeleton or other active components are not required
for microparticle aggregation. We suggest that this membrane-mediated
microparticle aggregation is a reason behind reported long retention times of
polymer microparticles in organisms.Comment: 20 pages, 11 figures (including supporting material
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