10,942 research outputs found
The Meeting of Acquaintances: A Cost-efficient Authentication Scheme for Light-weight Objects with Transient Trust Level and Plurality Approach
Wireless sensor networks consist of a large number of distributed sensor
nodes so that potential risks are becoming more and more unpredictable. The new
entrants pose the potential risks when they move into the secure zone. To build
a door wall that provides safe and secured for the system, many recent research
works applied the initial authentication process. However, the majority of the
previous articles only focused on the Central Authority (CA) since this leads
to an increase in the computation cost and energy consumption for the specific
cases on the Internet of Things (IoT). Hence, in this article, we will lessen
the importance of these third parties through proposing an enhanced
authentication mechanism that includes key management and evaluation based on
the past interactions to assist the objects joining a secured area without any
nearby CA. We refer to a mobility dataset from CRAWDAD collected at the
University Politehnica of Bucharest and rebuild into a new random dataset
larger than the old one. The new one is an input for a simulated authenticating
algorithm to observe the communication cost and resource usage of devices. Our
proposal helps the authenticating flexible, being strict with unknown devices
into the secured zone. The threshold of maximum friends can modify based on the
optimization of the symmetric-key algorithm to diminish communication costs
(our experimental results compare to previous schemes less than 2000 bits) and
raise flexibility in resource-constrained environments.Comment: 27 page
Research on the Application of E-commerce to Small and Medium Enterprises (SMEs): the Case of India
SMEs account for a large proportion and play an important role in the development of each country in the world, including India. The globalization will bring many advantages for enterprises however SMEs will face fierce competition at the local, national and International level. In order to maintain and promote the important role of SMEs in the context of increased competition, SMEs have to change and adopt new technologies. E-commerce and digital technologies are bringing opportunities to help SMEs improve their competitiveness, narrow the gap with big enterprises thanks to their fairness and flexibility of the digital business environment. According to UNIDO (2017), India is one of the countries successfully applying e-commerce to SMEs. Contributing to this success is the important role of the Indian government. Therefore, this paper focuses on researching the application of e-commerce to SMEs in terms of the role of government in promoting and creating an ecosystem for SMEs and e-commerce development
Covalency and the metal-insulator transition in titanate and vanadate perovskites
A combination of density functional and dynamical mean-field theory is
applied to the perovskites SrVO, LaTiO and LaVO. We show that
DFT+DMFT in conjunction with the standard fully localized-limit (FLL)
double-counting predicts that LaTiO and LaVO are metals even though
experimentally they are correlation-driven ("Mott") insulators. In addition,
the FLL double counting implies a splitting between oxygen and transition
metal levels which differs from experiment. Introducing into the theory an
\textit{ad hoc} double counting correction which reproduces the experimentally
measured insulating gap leads also to a - splitting consistent with
experiment if the on-site interaction is chosen in a relatively narrow
range ( eV). The results indicate that these early transition
metal oxides will serve as critical test for the formulation of a general
\textit{ab initio} theory of correlated electron metals.Comment: 5 pages, 3 figure
Folding model study of the charge-exchange scattering to the isobaric analog state and implication for the nuclear symmetry energy
The Fermi transition (\Delta L=\Delta S=0 and \Delta T=1) between the nuclear
isobaric analog states (IAS), induced by the charge-exchange (p,n) or (3He,t)
reaction, can be considered as "elastic" scattering of proton or 3He by the
isovector term of the optical potential (OP) that flips the projectile isospin.
The accurately measured (p,n) or (3He,t) scattering cross-section to the IAS
can be used, therefore, to probe the isospin dependence of the proton or 3He
optical potential. Within the folding model, the isovector part of the OP is
determined exclusively by the neutron-proton difference in the nuclear
densities and the isospin dependence of the effective nucleon-nucleon (NN)
interaction. Because the isovector coupling explicitly links the isovector part
of the proton or 3He optical potential to the cross section of the
charge-exchange (p,n) or (3He,t) scattering to the IAS, the isospin dependence
of the effective (in-medium) NN interaction can be well tested in the folding
model analysis of these charge-exchange reactions. On the other hand, the same
isospin- and density dependent NN interaction can also be used in a
Hartree-Fock calculation of asymmetric nuclear matter, to estimate the nuclear
matter energy and its asymmetry part (the nuclear symmetry energy). As a
result, the fine-tuning of the isospin dependence of the effective NN
interaction against the measured (p,n) or (3He,t) cross sections should allow
us to make some realistic prediction of the nuclear symmetry energy and its
density dependence.Comment: Accepted for publication in European Physical Journal A - "Hadrons
and Nuclei
On "the authentic damping mechanism" of the phonon damping model
Some general features of the phonon damping model are presented. It is
concluded that the fits performed within this model have no physical content
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