47,981 research outputs found
How Bebop Came to Be: The Early History of Modern Jazz
Bebop, despite its rather short lifespan, would become a key influence for every style that came after it. Bebop’s effects on improvisation, group structure, and harmony would be felt throughout jazz for decades to come, and the best known musicians of the bebop era are still regarded as some of the finest jazz musicians to ever take the stage. But the characteristics of bebop can easily be determined from the music itself. [excerpt
Business angel investing
Business angels are conventionally defined as high net worth individuals who invest their own money, along with their time and expertise, directly in unquoted companies in which they have no family connection, in the hope of financial gain. The term angel was coined by Broadway insiders in the early 1900s to describe wealthy theatre-goers who made high risk investments in theatrical productions. Angels invested in these shows primarily for the privilege of rubbing shoulders with the theatre personalities that they admired. The term business angel was given to those individuals who perform essentially the same function in a business context (Benjamin and Margulis, 2000: 5). There is a long tradition of angel investing in businesses (Sohl, 2003). Moreover, angel investing is now an international phenomenon, found in all developed economies and now diffusing to emerging economies such as China (Lui Tingchi, and Chen Po Chang,, 2007). However, it has only attracted the attention of researchers since the 1980s
Deterministically driven random walks in a random environment on Z
We introduce the concept of a deterministic walk in a deterministic
environment on a countable state space (DWDE). For the deterministic walk in a
fixed environment we establish properties analogous to those found in Markov
chain theory, but for systems that do not in general have the Markov property.
In particular, we establish hypotheses ensuring that a DWDE on is either
recurrent or transient. An immediate consequence of this result is that a
symmetric DWDE on is recurrent. Moreover, in the transient case, we show
that the probability that the DWDE diverges to is either 0 or 1. In
certain cases we compute the direction of divergence in the transient case
Equilibrium currents in quantum double ring system: A non-trivial role of system-reservoir coupling
Amperes law states that the magnetic moment of a ring is given by current
times the area enclosed. Also from equilibrium statistical mechanics it is
known that magnetic moment is the derivative of free energy with respect to
magnetic field. In this work we analyze a quantum double ring system
interacting with a reservoir. A simple S-Matrix model is used for
system-reservoir coupling. We see complete agreement between the aforesaid two
definitions when coupling between system and reservoir is weak, increasing the
strength of coupling parameter however leads to disagreement between the two.
Thereby signifying the important role played by the coupling parameter in
mesoscopic systems.Comment: 6 pages, 3 figure
Self-induced structure in the current-voltage characteristics of RSQUIDs
Resistive two-junction SQUIDs (RSQUIDs) made from high-temperature superconductors are being developed as narrow-linewidth tunable oscillators in the GHz frequency range. We present here the results of numerical simulation of RSQUIDs of this type. These studies have identified conditions where sub-harmonic steps and other features are apparent in the current-voltage characteristics, driven by the internally-generated heterodyne frequency. The behavior is sensitive to the frequency (set by the voltage across the resistive element in the RSQUID), the temperature and also the loop inductance. We have studied the effects of thermal noise on these features. We also assess how these effects might be observed, and consider how they might affect practical applications of high frequency heterodyne RSQUID oscillators
Instabilities in Zakharov Equations for Laser Propagation in a Plasma
F.Linares, G.Ponce, J-C.Saut have proved that a non-fully dispersive Zakharov
system arising in the study of Laser-plasma interaction, is locally well posed
in the whole space, for fields vanishing at infinity. Here we show that in the
periodic case, seen as a model for fields non-vanishing at infinity, the system
develops strong instabilities of Hadamard's type, implying that the Cauchy
problem is strongly ill-posed
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