8,956 research outputs found
Inter-Cloud Data Security Strategies
Cloud computing is a complex infrastructure of software, hardware,
processing, and storage that is available as a service. Cloud computing offers
immediate access to large numbers of the world's most sophisticated
supercomputers and their corresponding processing power, interconnected at
various locations around the world, proffering speed in the tens of trillions
of computations per second. Information in databases and software scattered
around the Internet. There are many service providers in the internet, we can
call each service as a cloud, each cloud service will exchange data with other
cloud, so when the data is exchanged between the clouds, there exist the
problem of security. Security is an important issue for cloud computing, both
in terms of legal compliance and user trust, and needs to be considered at
every phase of design. In contrast to traditional solutions, where the IT
services are under proper physical, logical and personnel controls, Cloud
Computing moves the application software and databases to the large data
centers, where the management of the data and services may not be trustworthy.
This unique attribute, however, poses many new security challenges. Cloud
computing seems to offer some incredible benefits for communicators.Comment: 5 pages, 1 Table. arXiv admin note: text overlap with
arXiv:0907.2485, arXiv:0903.0694 by other authors without attributio
Cloud Computing -- An Approach with Modern Cryptography
In this paper we are proposing an algorithm which uses AES technique of
128/192/256 bit cipher key in encryption and decryption of data. AES provides
high security as compared to other encryption techniques along with RSA. Cloud
computing provides the customer with the requested services. It refers to
applications and services that run on distributed network using virtualized
resources and accessed by common IP and network standard. While providing data
services it is becoming important to provide security for data. In cloud
computing keeping data secure is an important issue to be focused. Even though
AES was designed for military purposes, now a days it is been commercially
adopted worldwide as it can encrypt most confidential document, as well as it
can work in most restricted areas, and offers good defense against various
attack techniques, and security level to protect data for next 2-3 decades.Comment: 4 pages, 1 figur
Likelihood Ratio as Weight of Forensic Evidence: A Closer Look
The forensic science community has increasingly sought quantitative methods
for conveying the weight of evidence. Experts from many forensic laboratories
summarize their findings in terms of a likelihood ratio. Several proponents of
this approach have argued that Bayesian reasoning proves it to be normative. We
find this likelihood ratio paradigm to be unsupported by arguments of Bayesian
decision theory, which applies only to personal decision making and not to the
transfer of information from an expert to a separate decision maker. We further
argue that decision theory does not exempt the presentation of a likelihood
ratio from uncertainty characterization, which is required to assess the
fitness for purpose of any transferred quantity. We propose the concept of a
lattice of assumptions leading to an uncertainty pyramid as a framework for
assessing the uncertainty in an evaluation of a likelihood ratio. We
demonstrate the use of these concepts with illustrative examples regarding the
refractive index of glass and automated comparison scores for fingerprints.Comment: arXiv admin note: substantial text overlap with arXiv:1608.0759
Refined similarity hypothesis using 3D local averages
The refined similarity hypotheses of Kolmogorov, regarded as an important
ingredient of intermittent turbulence, has been tested in the past using
one-dimensional data and plausible surrogates of energy dissipation. We employ
data from direct numerical simulations, at the microscale Reynolds number
, on a periodic box of grid points to test the
hypotheses using 3D averages. In particular, we study the small-scale
properties of the stochastic variable ,
where is the longitudinal velocity increment and is
the dissipation rate averaged over a three-dimensional volume of linear size
. We show that is universal in the inertial subrange. In the dissipation
range, the statistics of are shown to depend solely on a local Reynolds
number
Conditional and Unique Coloring of Graphs (revised resubmission)
For integers and (where ), a conditional
-coloring of a graph is a proper -coloring of the vertices of
such that every vertex of degree in is adjacent to vertices with
at least differently colored neighbors. The smallest integer
for which a graph has a conditional -coloring is called the
th order conditional chromatic number, denoted by . For different
values of we first give results (exact values or bounds for
depending on ) related to the conditional coloring of graphs. Then we obtain
of certain parameterized graphs viz., windmill graph, line graph of
windmill graph, middle graph of friendship graph, middle graph of a cycle, line
graph of friendship graph, middle graph of complete -partite graph, middle
graph of a bipartite graph and gear graph. Finally we introduce \emph{unique
conditional colorability} and give some related results.Comment: Was submitted and withdrawn from Utilitas Mathematica prior to
submission to Graphs and Combinatorics where the paper in this version is now
under revie
Algorithms for enumerating and counting D2CS of some graphs
A D2CS of a graph G is a set with . We
study the problem of counting and enumerating D2CS of a graph. First we give an
explicit formula for the number of D2CS in a complete k-ary tree, Fibonacci
tree, binary Fibonacci tree and the binomial tree. Next we give an algorithm
for enumerating and counting D2CS of a graph. We then give a linear time
algorithm for finding all maximal D2CS in a strongly chordal graph.Comment: Six pages: Accepted for 15th annual conference of Gwalior academy of
mathematical sciences,Dec.12-14, 2010,New Delh
Conditional and Unique Coloring of Graphs
For integers , a conditional -coloring of a graph is a
proper -coloring of the vertices of such that every vertex of degree
in is adjacent to at least differently colored
vertices. Given , the smallest integer for which has a conditional
-coloring is called the th order conditional chromatic number
of . We give results (exact values or bounds for ,
depending on ) related to the conditional coloring of some graphs. We
introduce \emph{unique conditional colorability} and give some related results.
(Keywords. cartesian product of graphs; conditional chromatic number; gear
graph; join of graphs.)Comment: Under review in International Journal of Computer Mathematic
On conditional coloring of some graphs
For integers r and k > 0(k>r),a conditional (k, r)-coloring of a graph G is a
proper k-coloring of G such that every vertex v of G has at least min{r,d(v)}
differently colored neighbors, where d(v) is the degree of v. In this note, for
different values of r we obtain the conditional chromatic number of a grid
, and the strong product of and
(n,m being positive integers). Also, for integers and the second order conditional chromatic number (also known as dynamic
chromatic number) of the (t,n)-web graph is obtained.Comment: 9 pages: accepted for the 76th annual conference of the Indian
Mathematical Society,27-30 December 2010,Surat,Indi
Scaling exponents saturate in three-dimensional isotropic turbulence
From a database of direct numerical simulations of homogeneous and isotropic
turbulence, generated in periodic boxes of various sizes, we extract the
spherically symmetric part of moments of velocity increments and first verify
the following (somewhat contested) results: the -ths law holds in an
intermediate range of scales and that the second order exponent over the same
range of scales is {\it{anomalous}}, departing from the self-similar value of
and approaching a constant of at high Reynolds numbers. We compare
with some typical theories the dependence of longitudinal exponents as well as
their derivatives with respect to the moment order , and estimate the most
probable value of the H\"older exponent. We demonstrate that the transverse
scaling exponents saturate for large , and trace this trend to the presence
of large localized jumps in the signal. The saturation value of about at
the highest Reynolds number suggests, when interpreted in the spirit of
fractals, the presence of vortex sheets rather than more complex singularities.
In general, the scaling concept in hydrodynamic turbulence appears to be more
complex than even the multifractal description
Beam engineering for selective and enhanced coupling to multipolar resonances
Multipolar electromagnetic phenomena in sub-wavelength resonators are at the
heart of metamaterial science and technology. In this letter, we demonstrate
selective and enhanced coupling to specific multipole resonances via beam
engineering. We first derive an analytical method for determining the
scattering and absorption of spherical nanoparticles (NPs) that depends only on
the local electromagnetic field quantities within an inhomogeneous beam. Using
this analytical technique, we demonstrate the ability to drastically manipulate
the scattering properties of a spherical NP by varying illumination properties
and demonstrate the excitation of a longitudinal quadrupole mode that cannot be
accessed with conventional illumination. This work enhances the understanding
of fundamental light-matter interactions in metamaterials, and lays the
foundation for researchers to identify, quantify, and manipulate multipolar
light-matter interactions through optical beam engineering
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