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Valuing voluntary disclosure using a real options approach
This paper outlines a real options approach to valuing those announcements which are made by firms outside of their legal requirements. From the firm's perspective, information is disclosed only if the manager of the firm is sufficiently certain that the market response to the announcement will have a positive impact on the value of the firm.
When debt financing is possible we find that the manager adopts a more transparent disclosure policy, thus violating the Modigliani-Miller theorem on irrelevance of capital structure
The First Measurement of Cassiopeia A's Forward Shock Expansion Rate
We have obtained a second epoch observation of the Cassiopeia A supernova
remnant (SNR) with the Chandra X-ray Observatory to measure detailed X-ray
proper motions for the first time. Both epoch observations are 50 ks exposures
of the ACIS-S3 chip and they are separated by 2 years. Measurements of the thin
X-ray continuum dominated filaments located around the edge of the remnant
(that are identified with the forward shock) show expansion rates from 0.02%/yr
to 0.33%/yr. Many of these filaments are therefore significantly decelerated.
Their median value of 0.21%/yr is equal to the median expansion of the bright
ring (0.21%/yr) as measured with Einstein and ROSAT. This presents a conundrum
if the motion of the bright ring is indicative of the reverse shock speed. We
have also re-evaluated the motion of the radio bright ring with emphasis on
angle-averaged emissivity profiles. Our new measurement of the expansion of the
angle-averaged radio bright ring is 0.07 plus or minus 0.03%/yr, somewhat
slower than the previous radio measurements of 0.11%/yr which were sensitive to
the motions of small-scale features. We propose that the expansion of the
small-scale bright ring features in the optical, X-ray, and radio do not
represent the expansion of the reverse shock, but rather represent a
brightness-weighted average of ejecta passing through and being decelerated by
the reverse shock. The motion of the reverse shock, itself, is then represented
by the motion of the angle-averaged emissivity profile of the radio bright
ring.Comment: accepted to Ap
Comment on "Electron transport through correlated molecules computed using the time-independent Wigner function: Two critical tests"
The many electron correlated scattering (MECS) approach to quantum electronic
transport was investigated in the linear response regime [I. Baldea and H.
Koeppel, Phys. Rev. B. 78, 115315 (2008)]. The authors suggest, based on
numerical calculations, that the manner in which the method imposes boundary
conditions is unable to reproduce the well-known phenomena of conductance
quantization. We introduce an analytical model and demonstrate that conductance
quantization is correctly obtained using open system boundary conditions within
the MECS approach.Comment: 18 pages, 4 figures. Physical Review B, to appea
Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 4: Advanced fan section aerodynamic analysis
The purpose of this study is the development of a three-dimensional Euler/Navier-Stokes flow analysis for fan section/engine geometries containing multiple blade rows and multiple spanwise flow splitters. An existing procedure developed by Dr. J. J. Adamczyk and associates and the NASA Lewis Research Center was modified to accept multiple spanwise splitter geometries and simulate engine core conditions. The procedure was also modified to allow coarse parallelization of the solution algorithm. This document is a final report outlining the development and techniques used in the procedure. The numerical solution is based upon a finite volume technique with a four stage Runge-Kutta time marching procedure. Numerical dissipation is used to gain solution stability but is reduced in viscous dominated flow regions. Local time stepping and implicit residual smoothing are used to increase the rate of convergence. Multiple blade row solutions are based upon the average-passage system of equations. The numerical solutions are performed on an H-type grid system, with meshes being generated by the system (TIGG3D) developed earlier under this contract. The grid generation scheme meets the average-passage requirement of maintaining a common axisymmetric mesh for each blade row grid. The analysis was run on several geometry configurations ranging from one to five blade rows and from one to four radial flow splitters. Pure internal flow solutions were obtained as well as solutions with flow about the cowl/nacelle and various engine core flow conditions. The efficiency of the solution procedure was shown to be the same as the original analysis
Sleeping on a problem: the impact of sleep disturbance on intensive care patients - a clinical review
Sleep disturbance is commonly encountered amongst intensive care patients and has significant psychophysiological effects, which protract recovery and increases mortality. Bio-physiological monitoring of intensive care patients reveal alterations in sleep architecture, with reduced sleep quality and continuity. The etiological causes of sleep disturbance are considered to be multifactorial, although environmental stressors namely, noise, light and clinical care interactions have been frequently cited in both subjective and objective studies. As a result, interventions are targeted towards modifiable factors to ameliorate their impact. This paper reviews normal sleep physiology and the impact that sleep disturbance has on patient psychophysiological recovery, and the contribution that the clinical environment has on intensive care patients' sleep
Software Engineering meets Problem-based Learning
A problem-driven approach for teaching software engineering to undergraduate students is entering its third year at the Department of Computer Science at NUI, Maynooth
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