1,807 research outputs found
On the Micro-Dynamics of a Cash-in-Advance Economy (revised version of WP 04-12)
The purpose of this paper is to develop a general equilibrium model with money and trade taking place at disequilibrium prices. There are multiple markets being visited sequentially and transactions occur along the adjustment path. This implies quantity rationing to clear the market and we assume that there are cash-in-advance constraints on the transactions. The updating of the prices and cash balances along the way makes it necessary for agents to reconsider their trading plans subject to new information due to substitution and spill-over effects. The dynamics of this disequilibrium re-optimization process are shown to depend crucially on the exchange mechanisms that are imposed. One of the results is that the introduction of a cash-in-advance constraint does not help in stabilizing the fluctuations of cash balances, even though it does prevent debts from occurring outside of equilibrium.
Interconversion of Prony series for relaxation and creep
Various algorithms have been proposed to solve the interconversion equation of linear viscoelasticity when Prony series are used for the relaxation and creep moduli, G(t) and J(t). With respect to a Prony series for G(t), the key step in recovering the corresponding Prony series for J(t) is the determination of the coefficients {jk} of terms in J(t). Here, the need to solve a poorly conditioned matrix equation for the {jk} is circumvented by deriving elementary and easily evaluated analytic formulae for the {jk} in terms of the derivative dG(s)/ds of the Laplace transform G(s) of G(t)
The neurotropic black yeast Exophiala dermatitidis has a possible origin in the tropical rain forest
The black yeast Exophiala dermatitidis is known as a rare
etiologic agent of neurotropic infections in humans, occurring particularly in
East and Southeast Asia. In search of its natural habitat, a large sampling
was undertaken in temperate as well as in tropical climates. Sampling sites
were selected on the basis of the origins of previously isolated strains, and
on the basis of physiological properties of the species, which also determined
a selective isolation protocol. The species was absent from outdoor
environments in the temperate climate, but present at low abundance in
comparable habitats in the tropics. Positive outdoor sites particularly
included faeces of frugivorous birds and bats, in urban as well as in natural
areas. Tropical fruits were found E. dermatitidis positive at low
incidence. Of the human-made environments sampled, railway ties contaminated
by human faeces and oily debris in the tropics were massively positive, while
the known abundance of the fungus in steam baths was confirmed. On the basis
of the species' oligotrophy, thermotolerance, acidotolerance, moderate
osmotolerance, melanization and capsular yeast cells a natural life cycle in
association with frugivorous animals in foci in the tropical rain forest,
involving passage of living cells through the intestinal tract was
hypothesized. The human-dominated environment may have become contaminated by
ingestion of wild berries carrying fungal propagule
Analysis of ADCP data above a bottom observatory
A 300-kHz ADCP was set on GEOSTAR, a six-m3 deep-sea observatory. It was operated with cells of 80 cm during a three-week test experiment at 42-m water depth in
the northern Adriatic sub-basin. Although it provided valuable data about the horizontal current field over most of the water column, it also allowed specifying the wake disturbances induced by the observatory. These disturbances are characterised by vertical velocities that
are significant up to ~20 m above seafloor (echo intensity data suggest that the wake can even reach the surface), and by inclinations of the bottom nepheloïd layer (as deduced from differences in echo intensities from beam to beam). Our analysis is validated by consistent
relationships between the horizontal current direction and speed on one side and the characteristics of both dynamical (vertical velocity) and non-dynamical (echo intensity) parameters on the other side. It is in good agreement with the simulations from a numerical model, and hence specifies the sensitivity (especially with respect to echo intensity) and accuracy of an instrument usually operated within fields of current and scatterers not disturbed by the device supporting it. In addition, the error velocity parameter displays
specific characteristics that easily allow specifying the thickness of the layer disturbed by the observatory, thus providing a technique to validate the quality of data acquired in similar conditions
TOWARDS FULLY AUTOMATED DIGITAL ALIBIS WITH SOCIAL INTERACTION
Digital traces found on local hard drives as a result of online activities have become very valuable in reconstructing events in digital forensic investigations. This paper demonstrates that forged alibis can be created for online activities and social interactions. In particular, a novel, automated framework is presented that uses social interactions to create false digital alibis. The framework simulates user activity and supports communications via email as well as instant messaging using a chatbot. The framework is evaluated by extracting forensic artifacts and comparing them with the results obtained from a human user study
The neurotropic black yeast Exophiala dermatitidis has a possible origin in the tropical rain forest
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