7,974 research outputs found
A Lightweight and Attack Resistant Authenticated Routing Protocol for Mobile Adhoc Networks
In mobile ad hoc networks, by attacking the corresponding routing protocol,
an attacker can easily disturb the operations of the network. For ad hoc
networks, till now many secured routing protocols have been proposed which
contains some disadvantages. Therefore security in ad hoc networks is a
controversial area till now. In this paper, we proposed a Lightweight and
Attack Resistant Authenticated Routing Protocol (LARARP) for mobile ad hoc
networks. For the route discovery attacks in MANET routing protocols, our
protocol gives an effective security. It supports the node to drop the invalid
packets earlier by detecting the malicious nodes quickly by verifying the
digital signatures of all the intermediate nodes. It punishes the misbehaving
nodes by decrementing a credit counter and rewards the well behaving nodes by
incrementing the credit counter. Thus it prevents uncompromised nodes from
attacking the routes with malicious or compromised nodes. It is also used to
prevent the denial-of-service (DoS) attacks. The efficiency and effectiveness
of LARARP are verified through the detailed simulation studies.Comment: 14 Pages, IJWM
DPOAE in HIV infected adults
HIV infection is associated with impairment of hearing function, at any stage of disease causing complication to the external, middle, inner ear and CNS. Audiological manifestation of HIV is a direct consequence of virus or secondary to the pharmacological treatment or viral complication. \ud
Objectives: There is paucity of information pertaining to hearing status in HIV. As the deafness can occur at any stage of HIV with varying degree and people with HIV live longer, there is need to address the hearing problems in these individuals. So this study aimed detecting the outer hair cell functioning by doing DPOAE in normal hearing HIV infected adults.\ud
Method: The experimental group comprised of 12 HIV infected (24 ears) within 20 to 40 years. The age matched control group comprised of 15 subjects (30 ears). All the subjects had normal hearing sensitivity. Initially puretone audiometry and immittance was performed for the subject selection. Subsequently DPOAE procedure was done. \ud
Results: The DPOAE was abnormal in 50% of the subjects.\ud
Conclusion: It can be concluded that the cochlear involvement is a common observation in HIV infected individuals. DPOAE test can be used as a tool for early identification of cochlear pathology in HIV infected
Transition from radiatively inefficient to cooling dominated phase in two temperature accretion discs around black holes
We investigate the transition of a radiatively inefficient phase of a viscous
two temperature accreting flow to a cooling dominated phase and vice versa
around black holes. Based on a global sub-Keplerian accretion disc model in
steady state, including explicit cooling processes self-consistently, we show
that general advective accretion flow passes through various phases during its
infall towards a black hole. Bremsstrahlung, synchrotron and inverse
Comptonization of soft photons are considered as possible cooling mechanisms.
Hence the flow governs a much lower electron temperature ~10^8 - 10^{9.5}K
compared to the hot protons of temperature ~10^{10.2} - 10^{11.8}K in the range
of the accretion rate in Eddington units 0.01 - 100. Therefore, the solutions
may potentially explain the hard X-rays and the gamma-rays emitted from AGNs
and X-ray binaries. We finally compare the solutions for two different regimes
of viscosity and conclude that a weakly viscous flow is expected to be cooling
dominated compared to its highly viscous counterpart which is radiatively
inefficient. The flow is successfully able to reproduce the observed
luminosities of the under-fed AGNs and quasars (e.g. Sgr A*), ultra-luminous
X-ray sources (e.g. SS433), as well as the highly luminous AGNs and
ultra-luminous quasars (e.g. PKS 0743-67) at different combinations of the mass
accretion rate and ratio of specific heats.Comment: 13 pages including 8 figures; couple of typos corrected; to appear in
Research in Astronomy and Astrophysic
The Transformation of Microfinance in India: Experiences, Options and Future
The paper looks at the growth and transformation of microfinance organisations (MFO) in India. We first, define microfinance and identify its "value attributes". Having chosen only those MFOs that have microfinance as the core, we look at the transformation experiences. To understand the transformation experiences better, we identify issues that trigger transformation viz: size, diversity of services, financial sustainability, focus and taxation. Having identified these we look at transformation experiences internationally. We examine the Bolivian, Kenyan, Bangladeshi and the Indonesian experience. We then look at the Indian experiences. We argue that the transformation experiences in India are not large in number. However, we have found that there are three forms of organisations that seem to be popular in the microfinance sector - the Non-Banking Finance Companies, the Banks - both Local Area Banks and Urban Co-operative Banks and the Co-operatives. We then argue that in the Indian case, we find that the MFO spins off from the NGO rather than the NGO transforming itself. Having examined various options, we conclude that there is no ideal or easy path for MFOs to mainstream in India. This has implications for regulatory framework. We argue that there should be regulatory changes that allow smaller MFOs to get into more complex forms as they grow organically. We also argue that NGOs should be allowed to invest in the equity of MFOs and MFO promoted banks, as is the case in Bolivia and Africa. We maintain that entry norms on capitalisation for the current forms of organisations (NBFCs, Co-ops and Banks) need not be changed to ensure only genuine MFOs make use of the legislation and not other organisations masquerading as MFOs.
Asynchronous Gossip for Averaging and Spectral Ranking
We consider two variants of the classical gossip algorithm. The first variant
is a version of asynchronous stochastic approximation. We highlight a
fundamental difficulty associated with the classical asynchronous gossip
scheme, viz., that it may not converge to a desired average, and suggest an
alternative scheme based on reinforcement learning that has guaranteed
convergence to the desired average. We then discuss a potential application to
a wireless network setting with simultaneous link activation constraints. The
second variant is a gossip algorithm for distributed computation of the
Perron-Frobenius eigenvector of a nonnegative matrix. While the first variant
draws upon a reinforcement learning algorithm for an average cost controlled
Markov decision problem, the second variant draws upon a reinforcement learning
algorithm for risk-sensitive control. We then discuss potential applications of
the second variant to ranking schemes, reputation networks, and principal
component analysis.Comment: 14 pages, 7 figures. Minor revisio
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