2,462 research outputs found
A Model for Quantum Stochastic Absorption in Absorbing Disordered Media
Wave propagation in coherently absorbing disordered media is generally
modeled by adding a complex part to the real part of the potential. In such a
case, it is already understood that the complex potential plays a duel role; it
acts as an absorber as well as a reflector due to the mismatch of the phase of
the real and complex parts of the potential. Although this model gives expected
results for weakly absorbing disordered media, it gives unphysical results for
the strong absorption regime where it causes the system to behave like a
perfect reflector. To overcome this issue, we develop a model here using
stochastic absorption for the modeling of absorption by "fake", or "side",
channels obviating the need for a complex potential. This model of stochastic
absorption eliminates the reflection that is coupled with the absorption in the
complex potential model and absorption is proportional to the magnitude of the
absorbing parameter. Solving the statistics of the reflection coefficient and
its phase for both the models, we argue that stochastic absorption is a
potentially better way of modeling absorbing disordered media.Comment: 5 pages, 4 figure
Community and Institutional Led Multi-Disciplinary Approaches in Implementation of Integrated Watershed Management in India A Case study from Karnataka State
Since independence, reforms towards Panchayat Raj Institutions (PRIs) have focused on designing of legal and administrative structures that institutionalize decentralized governance and planning, while guaranteeing that such a system does not allow the local elite to dominate the marginalized units of the people. With the advent of the 73rd amendment in Indian constitution, the panchayat system is looked as a significant development in handling rural governance in India. In this aspect, the state of Karnataka can be considered in many ways as one of the active states in promoting decentralization. Karnataka is in the forefront when it comes to devolution of functions and financial powers to PRIs. Hence, the current study has the broad objective to undertake a situational and adopting SWOT analysis to determine the strengths, weaknesses, opportunities, and threats (SWOT) related to existing Watershed committees and Water User Co-operative Societies in Karnataka under Integrated Watershed Management Programme (IWMP) in terms of the structure, function and factors influencing in implementation of Watershed programme in the state of Karnataka, India. The findings revealed that about 90 % percent of all committees are found to exist on record (structural level), SWOT analysis clearly shown that community-led water use associations are performing better than the department led water user associations in the implementation of IWMP. While the structure and legal status of PRIs have matured over the years, it is clearly recognized that true public involvement in progress and governance through PRIs has a long way to go.KEYWORDS: Decentralisation, Participatory Development, Local Governance, Integrated Watershed Management Programm
DeepFuse: A Deep Unsupervised Approach for Exposure Fusion with Extreme Exposure Image Pairs
We present a novel deep learning architecture for fusing static
multi-exposure images. Current multi-exposure fusion (MEF) approaches use
hand-crafted features to fuse input sequence. However, the weak hand-crafted
representations are not robust to varying input conditions. Moreover, they
perform poorly for extreme exposure image pairs. Thus, it is highly desirable
to have a method that is robust to varying input conditions and capable of
handling extreme exposure without artifacts. Deep representations have known to
be robust to input conditions and have shown phenomenal performance in a
supervised setting. However, the stumbling block in using deep learning for MEF
was the lack of sufficient training data and an oracle to provide the
ground-truth for supervision. To address the above issues, we have gathered a
large dataset of multi-exposure image stacks for training and to circumvent the
need for ground truth images, we propose an unsupervised deep learning
framework for MEF utilizing a no-reference quality metric as loss function. The
proposed approach uses a novel CNN architecture trained to learn the fusion
operation without reference ground truth image. The model fuses a set of common
low level features extracted from each image to generate artifact-free
perceptually pleasing results. We perform extensive quantitative and
qualitative evaluation and show that the proposed technique outperforms
existing state-of-the-art approaches for a variety of natural images.Comment: ICCV 201
Weak Lensing Effect on CMB in the Presence of a Dipole Anisotropy
We investigate weak lensing effect on cosmic microwave background (CMB) in
the presence of dipole anisotropy. The approach of flat-sky approximation is
considered. We determine the functions and that
appear in expressions of the lensed CMB power spectrum in the presence of a
dipole anisotropy. We determine the correction to B-mode power spectrum which
is found to be appreciable at low multipoles (). However, the temperature
and E-mode power spectrum are not altered significantly.Comment: 9 page
Significance of thermal fluctuations and hydrodynamic interactions in receptor-ligand mediated adhesive dynamics of a spherical particle in wall bound shear flow
The dynamics of adhesion of a spherical micro-particle to a ligand-coated
wall, in shear flow, is studied using a Langevin equation that accounts for
thermal fluctuations, hydrodynamic interactions and adhesive interactions.
Contrary to the conventional assumption that thermal fluctuations play a
negligible role at high Pclet numbers, we find that for particles
with low surface densities of receptors, rotational diffusion caused by
fluctuations about the flow and gradient directions aids in bond formation,
leading to significantly greater adhesion on average, compared to simulations
where thermal fluctuations are completely ignored. The role of wall
hydrodynamic interactions on the steady state motion of a particle, when the
particle is close to the wall, has also been explored. At high Pclet
numbers, the shear induced force that arises due to the stresslet part of the
Stokes dipole, plays a dominant role, reducing the particle velocity
significantly, and affecting the states of motion of the particle. The coupling
between the translational and rotational degrees of freedom of the particle,
brought about by the presence of hydrodynamic interactions, is found to have no
influence on the binding dynamics. On the other hand, the drag coefficient,
which depends on the distance of the particle from the wall, plays a crucial
role at low rates of bond formation. A significant difference in the effect of
both the shear force and the position dependent drag force, on the states of
motion of the particle, is observed when the Plet number is small.Comment: The manuscript has been accepted as an article in Physical Review E
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