485 research outputs found
Market Consistent Pricing of Insurance Products
We present the first step in a program to develop a comprehensive, unified equilibrium theory of asset and liability pricing. We give a mathematical framework for pricing insurance products in a multiperiod financial market. This framework reflects classical economic principles (like utility maximization) and generates pricing algorithms for non-hedgeable insurance risk
Analyticity and uniform stability in the inverse spectral problem for Dirac operators
We prove that the inverse spectral mapping reconstructing the square
integrable potentials on [0,1] of Dirac operators in the AKNS form from their
spectral data (two spectra or one spectrum and the corresponding norming
constants) is analytic and uniformly stable in a certain sense.Comment: 19 page
Multiplicative point process as a model of trading activity
Signals consisting of a sequence of pulses show that inherent origin of the
1/f noise is a Brownian fluctuation of the average interevent time between
subsequent pulses of the pulse sequence. In this paper we generalize the model
of interevent time to reproduce a variety of self-affine time series exhibiting
power spectral density S(f) scaling as a power of the frequency f. Furthermore,
we analyze the relation between the power-law correlations and the origin of
the power-law probability distribution of the signal intensity. We introduce a
stochastic multiplicative model for the time intervals between point events and
analyze the statistical properties of the signal analytically and numerically.
Such model system exhibits power-law spectral density S(f)~1/f**beta for
various values of beta, including beta=1/2, 1 and 3/2. Explicit expressions for
the power spectra in the low frequency limit and for the distribution density
of the interevent time are obtained. The counting statistics of the events is
analyzed analytically and numerically, as well. The specific interest of our
analysis is related with the financial markets, where long-range correlations
of price fluctuations largely depend on the number of transactions. We analyze
the spectral density and counting statistics of the number of transactions. The
model reproduces spectral properties of the real markets and explains the
mechanism of power-law distribution of trading activity. The study provides
evidence that the statistical properties of the financial markets are enclosed
in the statistics of the time interval between trades. A multiplicative point
process serves as a consistent model generating this statistics.Comment: 10 pages, 3 figure
Inverse spectral problems for Dirac operators with summable matrix-valued potentials
We consider the direct and inverse spectral problems for Dirac operators on
with matrix-valued potentials whose entries belong to ,
. We give a complete description of the spectral data
(eigenvalues and suitably introduced norming matrices) for the operators under
consideration and suggest a method for reconstructing the potential from the
corresponding spectral data.Comment: 32 page
Boundary relations and generalized resolvents of symmetric operators
The Kre\u{\i}n-Naimark formula provides a parametrization of all selfadjoint
exit space extensions of a, not necessarily densely defined, symmetric
operator, in terms of maximal dissipative (in \dC_+) holomorphic linear
relations on the parameter space (the so-called Nevanlinna families). The new
notion of a boundary relation makes it possible to interpret these parameter
families as Weyl families of boundary relations and to establish a simple
coupling method to construct the generalized resolvents from the given
parameter family. The general version of the coupling method is introduced and
the role of boundary relations and their Weyl families for the
Kre\u{\i}n-Naimark formula is investigated and explained.Comment: 47 page
Integrated Microfluidic Platform for Oral Diagnostics
While many point-of-care (POC) diagnostic methods have been developed for blood-borne analytes, development of saliva-based POC diagnostics is in its infancy. We have developed a portable microfluidic device for detection of potential biomarkers of periodontal disease in saliva. The device performs rapid microfluidic chip-based immunoassays (<3–10 min) with low sample volume requirements (10 ΜL) and appreciable sensitivity (nM–pM). Our microfluidic method facilitates hands-free saliva analysis by integrating sample pretreatment (filtering, enrichment, mixing) with electrophoretic immunoassays to quickly measure analyte concentrations in minimally pretreated saliva samples. The microfluidic chip has been integrated with miniaturized electronics, optical elements, such as diode lasers, fluid-handling components, and data acquisition software to develop a portable, self-contained device. The device and methods are being tested by detecting potential biomarkers in saliva samples from patients diagnosed with periodontal disease. Our microchip-based analysis can readily be extended to detection of biomarkers of other diseases, both oral and systemic, in saliva and other oral fluids.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73594/1/annals.1384.004.pd
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