7,192 research outputs found
Supplementary Role of Health Metrics for Reducing Total Fertility Rate in a North-Indian State.
Reducing Total Fertility Rate (TFR) amongst rural Indian couples from the current level is a significant challenge to the population control policies relying solely on the Government efforts. REACH strategy, based on health metrics, succeeded in lowering the TFR below replacement levels in a rural population of more than 300,000 in Rajasthan. The REACH strategy was first developed and demonstrated success in decreasing TFR in a pilot project by SHARE India in Medchal region of Andhra Pradesh utilizing designated workers, and was replicated in Rajgarh District of Rajasthan in cooperation with Bhoruka Charitable Trust (supervisor of ICDS and NRHM health workers in Rajgarh) using Government health workers. The success of the REACH strategy in both Rajasthan and previously in Andhra Pradesh holds promise as a tool to reduce TFR in other areas of rural India
Comparative study of evolution of residual stress state by local mechanical tensioning and laser processing of ferritic and austenitic structural steel welds.
Complex thermal stresses generated in welded structures are undesirable but inevitable in fusion welding. The presence of residual stresses can be detrimental to the integrity of a welded joint. In this research, redistribution of residual stress magnitude and profile was studied and compared in two multi-pass welded structural alloys (API X100 and 304L stainless steel) after cold rolling and laser processing. The residual stress field was studied by neutron diffraction using the SALSA strain scanner at their reactor neutron source at ILL, Grenoble. In addition to a complex distribution of residual stress state, multi-pass welds also forms dendritic grain structure, which are repeatedly heated, resulting in segregation of alloying elements. Dendritic grain structure is weaker and segregation of alloying elements may result in formation of corrosion microcells as well as reduction in overall corrosion prevention due to depletion of alloying elements in certain areas. The modification of as-welded residual stress state was done by cold rolling which was followed by laser processing to create a recrystallized microstructure to minimise segregation. The main objective of this study is to understand the suitability of this novel manufacturing technique to create a stress free weldment with recrystallised grain structure. Hardness evolution in the welded structures was scanned following welding, post weld cold rolling and cold rolling followed by laser processing. Hardness distribution in both the structural alloys showed a significant evidence of plastic deformation near the cap pass of the weld metal. Residual stress redistribution was observed up to 4 mm from the capping pass for ferritic steel, while in austenitic steel weld, post weld cold rolling was effective in modifying the residual stress redistribution throughout the entire thickness. Laser processing in both cases reinstated the as-welded residual stress distribution and resulted in softening of the strained area
On some strong Poincaré inequalities on Riemannian models and their improvements
We prove second and fourth order improved Poincaré type inequalities on the hyperbolic space involving Hardy-type remainder terms. Since theirs l.h.s. only involve the radial part of the gradient or of the laplacian, they can be seen as stronger versions of the classical Poincaré inequality. We show that such inequalities hold true on model manifolds as well, under suitable curvature assumptions and sharpness of some constants is also discussed
The Origins of a Rich Absorption Line Complex in a Quasar at Redshift 3.45
We discuss the nature and origin of a rich complex of narrow absorption lines
in the quasar J102325.31+514251.0 at redshift 3.447. We measure nine C
IV(\lambda1548,1551) absorption line systems with velocities from -1400 to
-6200 km/s, and full widths at half minimum ranging from 16 to 350 km/s. We
also detect other absorption lines in these systems, including H I, C III, N V,
O VI, and Si IV. Lower ionisation lines are not present, indicating a generally
high degree of ionisation in all nine systems. The total hydrogen column
densities range from <=10^{17.2} to 10^{19.1}cm^{-2}. We examine several
diagnostics to estimate more directly the location and origin of each absorber.
Four of the systems can be attributed to a quasar-driven outflow based on line
profiles that are smooth and broad compared to thermal line widths. Several
systems also have other indicators of a quasar outflow origin, including
partial covering. Altogether there is direct evidence for 6 of the 9 systems
forming in a quasar outflow. Consistent with a near-quasar origin, eight of the
systems have metallicity values or lower limits in the range Z >= 1-8 Z_{sun}.
The lowest velocity system, which has an ambiguous location, also has the
lowest metallicity, Z <= 0.3 Z_{sun}, and might form in a non-outflow
environment farther from the quasar. Overall, however, this complex of narrow
absorption lines can be identified with a highly structured, multi-component
outflow from the quasar. The high metallicities are similar to those derived
for other quasars at similar redshifts and luminosities, and are consistent
with evolution scenarios wherein quasars appear after the main episodes of star
formation and metal enrichment in the host galaxies.Comment: 16 pages, 12 figures, Accepted to MNRAS, July 201
Emergence of a non-scaling degree distribution in bipartite networks: a numerical and analytical study
We study the growth of bipartite networks in which the number of nodes in one
of the partitions is kept fixed while the other partition is allowed to grow.
We study random and preferential attachment as well as combination of both. We
derive the exact analytical expression for the degree-distribution of all these
different types of attachments while assuming that edges are incorporated
sequentially, i.e., a single edge is added to the growing network in a time
step. We also provide an approximate expression for the case when more than one
edge are added in a time step. We show that depending on the relative weight
between random and preferential attachment, the degree-distribution of this
type of network falls into one of four possible regimes which range from a
binomial distribution for pure random attachment to an u-shaped distribution
for dominant preferential attachment
The fractional porous medium equation on the hyperbolic space
We consider a nonlinear degenerate parabolic equation of porous medium type, whose diffusion is driven by the (spectral) fractional Laplacian on the hyperbolic space. We provide existence results for solutions, in an appropriate weak sense, for data belonging either to the usual Lp spaces or to larger (weighted) spaces determined either in terms of a ground state of the laplacian, or of the (fractional) Green’s function. For such solutions, we also prove different kind of smoothing effects, in the form of quantitative L1- L∞ estimates. To the best of our knowledge, this seems the first time in which the fractional porous medium equation has been treated on non-compact, geometrically non-trivial examples
Shape-invariant quantum Hamiltonian with position-dependent effective mass through second order supersymmetry
Second order supersymmetric approach is taken to the system describing motion
of a quantum particle in a potential endowed with position-dependent effective
mass. It is shown that the intertwining relations between second order partner
Hamiltonians may be exploited to obtain a simple shape-invariant condition.
Indeed a novel relation between potential and mass functions is derived, which
leads to a class of exactly solvable model. As an illustration of our
procedure, two examples are given for which one obtains whole spectra
algebraically. Both shape-invariant potentials exhibit harmonic-oscillator-like
or singular-oscillator-like spectra depending on the values of the
shape-invariant parameter.Comment: 16 pages, 5 figs; Present e-mail of AG: [email protected]
On Deterministic Sketching and Streaming for Sparse Recovery and Norm Estimation
We study classic streaming and sparse recovery problems using deterministic
linear sketches, including l1/l1 and linf/l1 sparse recovery problems (the
latter also being known as l1-heavy hitters), norm estimation, and approximate
inner product. We focus on devising a fixed matrix A in R^{m x n} and a
deterministic recovery/estimation procedure which work for all possible input
vectors simultaneously. Our results improve upon existing work, the following
being our main contributions:
* A proof that linf/l1 sparse recovery and inner product estimation are
equivalent, and that incoherent matrices can be used to solve both problems.
Our upper bound for the number of measurements is m=O(eps^{-2}*min{log n, (log
n / log(1/eps))^2}). We can also obtain fast sketching and recovery algorithms
by making use of the Fast Johnson-Lindenstrauss transform. Both our running
times and number of measurements improve upon previous work. We can also obtain
better error guarantees than previous work in terms of a smaller tail of the
input vector.
* A new lower bound for the number of linear measurements required to solve
l1/l1 sparse recovery. We show Omega(k/eps^2 + klog(n/k)/eps) measurements are
required to recover an x' with |x - x'|_1 <= (1+eps)|x_{tail(k)}|_1, where
x_{tail(k)} is x projected onto all but its largest k coordinates in magnitude.
* A tight bound of m = Theta(eps^{-2}log(eps^2 n)) on the number of
measurements required to solve deterministic norm estimation, i.e., to recover
|x|_2 +/- eps|x|_1.
For all the problems we study, tight bounds are already known for the
randomized complexity from previous work, except in the case of l1/l1 sparse
recovery, where a nearly tight bound is known. Our work thus aims to study the
deterministic complexities of these problems
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