69 research outputs found
Marginalization for rare event simulation in switching diffusions
In this paper we use splitting technique to estimate the probability of
hitting a rare but critical set by the continuous component of a switching
diffusion. Instead of following classical approach we use Wonham filter to
achieve multiple goals including reduction of asymptotic variance and exemption
from sampling the discrete components
The optimal hedging in a semi-Markov modulated market
This paper includes an original self contained proof of well-posedness of an
initial-boundary value problem involving a non-local parabolic PDE which
naturally arises in the study of derivative pricing in a generalized market
model. We call this market model a semi-Markov modulated market. Although a
wellposedness result of that problem is available in the literature, but this
recent paper has a different proof. Here the existence of solution is
established without invoking mild solution technique. We study the
well-posedness of the initial-boundary value problem via a Volterra integral
equation of second kind. The method of conditioning on stopping times was used
only for showing uniqueness. Furthermore, in the present study we find an
integral representation of the PDE problem which enables us to find a robust
numerical scheme to compute derivative of the solution. This study paves for
addressing many other interesting problems involving this new set of PDEs. Some
derivations of external cash flow corresponding to an optimal strategy are
presented. These quantities are extremely important when dealing with an
incomplete market. Apart from these, the risk measures for discrete trading are
formulated which may be of interest to the practitioners.Comment: 23 pages, 4 figure
Semi-implicit Integration and Data-Driven Model Order Reduction in Structural Dynamics with Hysteresis
Structural damping is known to be approximately rate-independent in many
cases. Popular models for rate-independent dissipation are hysteresis models;
and a highly popular hysteresis model is the Bouc-Wen model. If such hysteretic
dissipation is incorporated in a refined finite element model, then the
mathematical model includes the usual structural dynamics equations along with
nonlinear nonsmooth ordinary differential equations for a large number of
internal hysteretic states at Gauss points, to be used within the virtual work
calculation for dissipation. For such systems, numerical integration becomes
difficult due to both the distributed non-analytic nonlinearity of hysteresis
as well as the very high natural frequencies in the finite element model. Here
we offer two contributions. First, we present a simple semi-implicit
integration approach where the structural part is handled implicitly based on
the work of Pich\'e, and where the hysteretic part is handled explicitly. A
cantilever beam example is solved in detail using high mesh refinement.
Convergence is good for lower damping and a smoother hysteresis loop. For a
less smooth hysteresis loop and/or higher damping, convergence is observed to
be roughly linear on average. Encouragingly, the time step needed for stability
is much larger than the time period of the highest natural frequency of the
structural model. Subsequently, data from several simulations conducted using
the above semi-implicit method are used to construct reduced order models of
the system, where the structural dynamics is projected onto a small number of
modes and the number of hysteretic states is reduced significantly as well.
Convergence studies of error against the number of retained hysteretic states
show very good results
Reassessing the Restorative Prospectives of the King of Spices Black Pepper
Since ages, spices have been a crucial portion of human diets and trade. The bioactive principles in attendance are of noteworthy merit due to their advantageous probable against an array of disorders. Black pepper, amid piperine as its foremost element, holds affluent phytochemistry and also incorporates a number other important compounds like alkaloids, volatile oils and oleoresins. Piper nigrum is an imperative welfare spice owed to its anti-carcinogenic, antimicrobial, antioxidant apparent and gastro-defensive workings. Piperine also show evidence of speckled pharmacological characteristics like antidepressant, anti-inflammative, immunomodulatory, anticonvulsant, antihypertensive, antitumor, anti-tussive, pain reducing, antidiarrheal, antispasmodic, and cholesterol worsening . Piperine augments bioavailability of quite a few drugs and nutrients by restraining a variety of metabolising enzymes. This review is aimed to provide restructured information in recent progression of pharmacognosy, chemistry and pharmacological behavior of this miraculous King of Spices.
Keywords: Black Pepper, Piperine, Antioxidant, Bioavailability, King of Spice
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