16,810 research outputs found
Systemic Risk: Simulating Local Shocks To A Global System
Using our updated model of the payment exchange system within the banking industry, we have introduced sudden local economic shocks and calculated their effect on the stability of the financial system. Our results suggest that the probability of a total banking failure, i.e., the systemic risk of the system, is insignificant unless the degree of the shock and the degree of integration between banks are very large. We find that the larger the shock, i.e., the greater the amount of loss amongst all banks, and the more isolated banks are within the payment system, the greater the likelihood of a localized or global banking system failure. However, given the current limits percentages of capitol banks can loan each other, only worldwide economic crises of cataclysmic significance would cause a collapse of the entire banking system. Hence we affirm the findings of our previous work which considered the effects of a bank failure generated by factors internal to the banking system (internal instead of internal shocks), which suggest there is minimal systemic risk in an integrated, minimally regulated, banking system.
Local magnetic divertor for control of the plasma-limiter interaction in a tokamak
An experiment is described in which plasma flow to a tokamak limiter is controlled through the
use of a local toroidal divertor coil mounted inside the limiter itself. This coil produces a local
perturbed field B_C approximately equal to the local unperturbed toroidal field B_T ≃ 3 kG, such
that when B_C adds to B_T the field lines move into the limiter and the local plasma flow to it
increases by a factor as great as 1.6, and when B_C subtracts from B_T the field lines move away
from the limiter and the local plasma flow to it decreases by as much as a factor of 4. A simple
theoretical model is used to interpret these results. Since these changes occur without significantly
affecting global plasma confinement, such a control scheme may be useful for optimizing the
performance of pumped limiters
Diseases of Cultivated Lupines
The cultivation of lupines has been practiced in Europe for over a thousand years. Impoverished Greeks and Romans used lupine meal in their bread and farmers have long grown the plants for forage and green manure. Extensive cultivation of these plants would be expected because the seed, which consists of from 30 to 40 per cent protein, is high in food value and because relatively high yields can be obtained even under unfavorable conditions. Stock poisoning, however, has frequently resulted from consumption of these plants owing to the presence of harmful alkaloids. Such substances could be removed from the seeds, but only by soaking in water. Since this procedure required considerable time and energy and since the other parts of the plant could not be treated in this way, lupines have not been grown extensively in the past
Static inverters which sum a plurality of waves Patent
Describing static inverter with single or multiple phase outpu
Simulation of the Burridge-Knopoff Model of Earthquakes with Variable Range Stress Transfer
Simple models of earthquake faults are important for understanding the
mechanisms for their observed behavior, such as Gutenberg-Richter scaling and
the relation between large and small events, which is the basis for various
forecasting methods. Although cellular automaton models have been studied
extensively in the long-range stress transfer limit, this limit has not been
studied for the Burridge-Knopoff model, which includes more realistic friction
forces and inertia. We find that the latter model with long-range stress
transfer exhibits qualitatively different behavior than both the long-range
cellular automaton models and the usual Burridge-Knopoff model with nearest
neighbor springs, depending on the nature of the velocity-weakening friction
force. This result has important implications for our understanding of
earthquakes and other driven dissipative systems.Comment: 4 pages, 5 figures, published on Phys. Rev. Let
Analysis of CLL voltage-output resonant converters using describing functions
A new ac equivalent circuit for the CLL voltage output resonant converter is presented, that offers improved
accuracy compared with traditional FMA-based techniques. By employing describing function techniques, the nonlinear interaction of the parallel inductor, rectifier and load is replaced by a complex impedance, thereby facilitating the use of ac equivalent circuit analysis methodologies. Moreover, both continuous and discontinuous rectifier-current operating conditions are addressed. A generic normalized analysis of the converter is also presented. To further aid the designer, error maps are used to demonstrate the boundaries for providing accurate behavioral predictions. A comparison
of theoretical results with those from simulation studies and experimental measurements from a prototype converter, are also included as a means of clarifying the benefits of the proposed techniques
Tunneling magnetoresistance in devices based on epitaxial NiMnSb with uniaxial anisotropy
We demonstrate tunnel magnetoresistance (TMR) junctions based on a tri layer
system consisting of an epitaxial NiMnSb, aluminum oxide and CoFe tri layer.
The junctions show a tunnelling magnetoresistance of Delta R/R of 8.7% at room
temperature which increases to 14.7% at 4.2K. The layers show clear separate
switching and a small ferromagnetic coupling. A uniaxial in plane anisotropy in
the NiMnSb layer leads to different switching characteristics depending on the
direction in which the magnetic field is applied, an effect which can be used
for sensor applications.Comment: 8 pages, 3 figures, submitted to Appl. Phys. Let
Quantum Hall effect in narrow graphene ribbons
The edge states in the integer quantum Hall effect are known to be
significantly affected by electrostatic interactions leading to the formation
of compressible and incompressible strips at the boundaries of Hall bars. We
show here, in a combined experimental and theoretical analysis, that this does
not hold for the quantum Hall effect in narrow graphene ribbons. In our
graphene Hall bar, which is only 60 nm wide, we observe the quantum Hall effect
up to Landau level index k=2 and show within a zero free-parameter model that
the spatial extent of the compressible and incompressible strips is of a
similar magnitude as the magnetic length. We conclude that in narrow graphene
ribbons the single-particle picture is a more appropriate description of the
quantum Hall effect and that electrostatic effects are of minor importance.Comment: RevTex, 5 pages, 4 figures (matches published version
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