109,593 research outputs found
Modules with Pure Resolutions
We show that the property of a standard graded algebra R being Cohen-Macaulay
is characterized by the existence of a pure Cohen-Macaulay R-module
corresponding to any degree sequence of length at most depth(R). We also give a
relation in terms of graded Betti numbers, called the Herzog-Kuhl equations,
for a pure R-module M to satisfy the condition dim(R) - depth(R) = dim(M) -
depth(M). When R is Cohen-Macaulay, we prove an analogous result characterizing
all graded Cohen-Macaulay R-modules.Comment: 9 page
Multiplication Semigroups on Banach Function Spaces
In this paper we characterize multiplication operators induced by operator
valued maps on Banach function spaces. We also study multiplication semigroups
and stability of these operators.Comment: We want to withdraw the paper due to the paper needs a careful
revision and some proper citations are to be provided. Also there are certain
gaps in the results which need to be taken car
Alternative conformal quantum mechanics
We investigate a one dimensional quantum mechanical model, which is invariant
under translations and dilations but does not respect the conventional
conformal invariance. We describe the possibility of modifying the conventional
conformal transformation such that a scale invariant theory is also invariant
under this new conformal transformation
Analytical results connecting stellar structure parameters and extended reaction rates
Possible modification in the velocity distribution in the non-resonant
reaction rates leads to an extended reaction rate probability integral. The
closed form representation for these thermonuclear functions are used to obtain
the stellar luminosity and neutrino emission rates. The composite parameter {C}
that determines the standard nuclear reaction rate through the
Maxwell-Boltzmann energy distribution is extended to {C}^* by the extended
reaction rates through a more general distribution than the Maxwell-Boltzmann
distribution. The new distribution is obtained by the pathway model introduced
by Mathai in 2005 [Linear Algebra and Its Applications, 396, 317-328]. Simple
analytic models considered by various authors are utilized for evaluating
stellar luminosity and neutrino emission rates and are obtained in generalized
special functions such as Meijer's G-function and Fox's H-function. The
standard and extended non-resonant thermonuclear functions are compared by
plotting them. Behavior of the new energy distribution, more general than
Maxwell-Boltzmann is also studied.Comment: 20 pages, LaTe
DSDV, DYMO, OLSR: Link Duration and Path Stability
In this paper, we evaluate and compare the impact of link duration and path
stability of routing protocols; Destination Sequence Distance vector (DSDV),
Dynamic MANET On- Demand (DYMO) and Optimized Link State Routing (OLSR) at
different number of connections and node density. In order to improve the
efficiency of selected protocols; we enhance DYMO and OLSR. Simulation and
comparison of both default and enhanced routing protocols is carried out under
the performance parameters; Packet Delivery Ratio (PDR), Average End-to End
Delay (AE2ED) and Normalized Routing Overhead (NRO). From the results, we
observe that DYMO performs better than DSDV, MOD-OLSR and OLSR in terms of PDR,
AE2ED, link duration and path stability at the cost of high value of NRO
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