1,117 research outputs found
Impact of Japanese Mergers on Shareholder Wealth: An Analysis of Bidder and Target Companies
The market for corporate control in the second largest economy in the world behaves very different from that in the U.S. Using a sample of 91 mergers in the period 1982-2003 we document several distinctive features of this market in Japan. First, we show that in stark contrast to the pro-cyclical U.S. merger waves, mergers in Japan tend to be counter-cyclical, both with respect to the general economy as well as with respect to stock market valuations. Second, and again in contrast to the U.S. experience, we find that a significant fraction of Japanese mergers are orchestrated by the main banks; in such cases, mergers are not between two weak companies, but at least one of the merging companies is financially strong. Other distinctive features of Japanese mergers are the positive pre-announcement returns accruing to both bidders and targets, with bidders capturing approximately half the gains that accrue to target firms. We also find differential shareholder wealth effects in the bubble period (1982-1989), the early 1990s, and the post-financial regulation regime (1997-2003). Overall our results point to a market for corporate control that is distinctly less shareholder-centered than that in the U.S. and one where creditors play an important, perhaps dominant, role.mergers;Japanse mergers;corporate control;take-over
Impact of Japanese Mergers on Shareholder Wealth: An Analysis of Bidder and Target Companies
The market for corporate control in the second largest economy in the world behaves very different from that in the U.S. Using a sample of 91 mergers in the period 1982-2003 we document several distinctive features of this market in Japan. First, we show that in stark contrast to the pro-cyclical U.S. merger waves, mergers in Japan tend to be counter-cyclical, both with respect to the general economy as well as with respect to stock market valuations. Second, and again in contrast to the U.S. experience, we find that a significant fraction of Japanese mergers are orchestrated by the main banks; in such cases, mergers are not between two weak companies, but at least one of the merging companies is financially strong. Other distinctive features of Japanese mergers are the positive pre-announcement returns accruing to both bidders and targets, with bidders capturing approximately half the gains that accrue to target firms. We also find differential shareholder wealth effects in the bubble period (1982-1989), the early 1990s, and the post-financial regulation regime (1997-2003). Overall our results point to a market for corporate control that is distinctly less shareholder-centered than that in the U.S. and one where creditors play an important, perhaps dominant, role
Dephasing Times in a Non-degenerate Two-Dimensional Electron Gas
Studies of weak localization by scattering from vapor atoms for electrons on
a liquid helium surface are reported. There are three contributions to the
dephasing time. Dephasing by the motion of vapor atoms perpendicular to the
surface is studied by varying the holding field to change the characteristic
width of the electron layer at the surface. A change in vapor density alters
the quasi-elastic scattering length and the dephasing due to the motion of
atoms both perpendicular and parallel to the surface. Dephasing due to the
electron-electron interaction is dependent on the electron density.Comment: 4 pages, Revte
The Role of Covalent Functionalization in the Thermal Stability and Decomposition of Hybrid Layered Hydroxides
The room temperature synthesis of two Co-based hybrid layered hydroxides containing the same organic ligand (suberate [Sub]), one connected through purely electrostatic interactions (CoAl layered double hydroxide [LDH]), and the other covalently functionalized (α-CoII simonkolleite phase) has been carried out. The magnetic properties exhibit an acute difference in the magnetization temperatures (from ≈10 K for the CoAl-LDH to ≈55 K for the α-CoII). Moreover, the role of the covalent functionalization in the thermal stability and the decomposition has been investigated by a forefront characterization tool consisting of thermogravimetric analysis coupled with gas chromatography and mass spectrometry (TG-GC-MS). The LDH exhibits a higher thermal stability of ≈50 ºC with broad mass loss steps, whereas the water molecules interact stronger with the α-CoII(Sub) hybrid, suggesting a higher confinement in the interlayer space. Interestingly, at higher temperatures (>400 ºC), the α-CoII(Sub) gives rise to the selective formation of cycloheptanone, in contrast to the LDH phase leading to different carbonyl containing compounds. These findings offer new fundamental insights into the thermal behavior of hybrid materials based on layered hydroxides, highlighting the important role of covalent functionalization in its properties
Parametric generation of second sound in superfluid helium: linear stability and nonlinear dynamics
We report the experimental studies of a parametric excitation of a second
sound (SS) by a first sound (FS) in a superfluid helium in a resonance cavity.
The results on several topics in this system are presented: (i) The linear
properties of the instability, namely, the threshold, its temperature and
geometrical dependencies, and the spectra of SS just above the onset were
measured. They were found to be in a good quantitative agreement with the
theory. (ii) It was shown that the mechanism of SS amplitude saturation is due
to the nonlinear attenuation of SS via three wave interactions between the SS
waves. Strong low frequency amplitude fluctuations of SS above the threshold
were observed. The spectra of these fluctuations had a universal shape with
exponentially decaying tails. Furthermore, the spectral width grew continuously
with the FS amplitude. The role of three and four wave interactions are
discussed with respect to the nonlinear SS behavior. The first evidence of
Gaussian statistics of the wave amplitudes for the parametrically generated
wave ensemble was obtained. (iii) The experiments on simultaneous pumping of
the FS and independent SS waves revealed new effects. Below the instability
threshold, the SS phase conjugation as a result of three-wave interactions
between the FS and SS waves was observed. Above the threshold two new effects
were found: a giant amplification of the SS wave intensity and strong resonance
oscillations of the SS wave amplitude as a function of the FS amplitude.
Qualitative explanations of these effects are suggested.Comment: 73 pages, 23 figures. to appear in Phys. Rev. B, July 1 st (2001
Observation of Crossover from Ballistic to Diffusion Regime for Excimer Molecules in Superfluid He
We have measured the temperature dependence of the time of flight of helium
excimer molecules He2* in superfluid 4He and find that the molecules behave
ballistically below 100mK and exhibit Brownian motion above 200 mK. In the
intermediate temperature range the transport cannot be described by either of
the models.Comment: 8 pages, 6 figures, submitted to the Proceedings of the International
Conference on Quantum Fluids and Solids 201
Vortex structure and resistive transitions in high-Tc superconductors
The nature of the resistive transition for a current applied parallel to the
magnetic field in high-Tc materials is investigated by numerical simulation on
the three dimensional Josephson junction array model. It is shown by using
finite size scaling that for samples with disorder the critical temperature Tp
for the c axis resistivity corresponds to a percolation phase transition of
vortex lines perpendicularly to the applied field. The value of Tp is higher
than the critical temperature for j perpendicular to H, but decreases with the
thickness of the sample and with anisotropy. We predict that critical behavior
around Tp should reflect in experimentally accessible quantities, as the I-V
curves.Comment: 8 pages + 6 figure
A Multifaceted Mathematical Approach for Complex Systems
Applied mathematics has an important role to play in developing the tools needed for the analysis, simulation, and optimization of complex problems. These efforts require the development of the mathematical foundations for scientific discovery, engineering design, and risk analysis based on a sound integrated approach for the understanding of complex systems. However, maximizing the impact of applied mathematics on these challenges requires a novel perspective on approaching the mathematical enterprise. Previous reports that have surveyed the DOE's research needs in applied mathematics have played a key role in defining research directions with the community. Although these reports have had significant impact, accurately assessing current research needs requires an evaluation of today's challenges against the backdrop of recent advances in applied mathematics and computing. To address these needs, the DOE Applied Mathematics Program sponsored a Workshop for Mathematics for the Analysis, Simulation and Optimization of Complex Systems on September 13-14, 2011. The workshop had approximately 50 participants from both the national labs and academia. The goal of the workshop was to identify new research areas in applied mathematics that will complement and enhance the existing DOE ASCR Applied Mathematics Program efforts that are needed to address problems associated with complex systems. This report describes recommendations from the workshop and subsequent analysis of the workshop findings by the organizing committee
Magneto-shear modes and a.c. dissipation in a two-dimensional Wigner crystal
The a.c. response of an unpinned and finite 2D Wigner crystal to electric
fields at an angular frequency has been calculated in the dissipative
limit, , where is the scattering rate. For
electrons screened by parallel electrodes, in zero magnetic field the
long-wavelength excitations are a diffusive longitudinal transmission line mode
and a diffusive shear mode. A magnetic field couples these modes together to
form two new magneto-shear modes. The dimensionless coupling parameter where and are the
speeds of transverse and longitudinal sound in the collisionless limit and
and are the tensor components of the
magnetoconductivity. For , both the coupled modes contribute
to the response of 2D electrons in a Corbino disk measurement of
magnetoconductivity. For , the electron crystal rotates rigidly in
a magnetic field. In general, both the amplitude and phase of the measured a.c.
currents are changed by the shear modulus. In principle, both the
magnetoconductivity and the shear modulus can be measured simultaneously.Comment: REVTeX, 7 pp., 4 eps figure
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