16,854 research outputs found
Hunger and Satiety Mechanisms and Their Potential Exploitation in the Regulation of Food Intake
Acknowledgments Tehmina Amin is the Project Manager and Julian Mercer is Project Coordinator for Full4Health. Both are funded by the Full4Health project (grant agreement no. 266408) under the EU Seventh Framework Programme (FP7/2007–2013). Julian Mercer is funded by the Scottish Government, Rural and Environment Science and Analytical Services Division, Food, Land and People programme. He is also a partner in FP7 projects: NeuroFAST (grant agreement no. 245099) and SATIN (grant agreement no. 289800).Peer reviewedPublisher PD
Sparse Array DFT Beamformers for Wideband Sources
Sparse arrays are popular for performance optimization while keeping the
hardware and computational costs down. In this paper, we consider sparse arrays
design method for wideband source operating in a wideband jamming environment.
Maximizing the signal-to-interference plus noise ratio (MaxSINR) is adopted as
an optimization objective for wideband beamforming. Sparse array design problem
is formulated in the DFT domain to process the source as parallel narrowband
sources. The problem is formulated as quadratically constraint quadratic
program (QCQP) alongside the weighted mixed -norm squared
penalization of the beamformer weight vector. The semidefinite relaxation (SDR)
of QCQP promotes sparse solutions by iteratively re-weighting beamformer based
on previous iteration. It is shown that the DFT approach reduces the
computational cost considerably as compared to the delay line approach, while
efficiently utilizing the degrees of freedom to harness the maximum output SINR
offered by the given array aperture
Prethermalization Production of Dark Matter
At the end of inflation, the inflaton field decays into an initially
nonthermal population of relativistic particles which eventually thermalize. We
consider the production of dark matter from this relativistic plasma, focusing
on the prethermal phase. We find that for a production cross section
with , the present dark matter abundance is produced
during the prethermal phase of its progenitors. For , entropy
production during reheating makes the nonthermal contribution to the present
dark matter abundance subdominant compared to that produced thermally. As
specific examples, we verify that the nonthermal contribution is irrelevant for
gravitino production in low scale supersymmetric models () and is dominant
for gravitino production in high scale supersymmetry models ().Comment: 12 pages, 4 figure
Power Control for D2D Underlay in Multi-cell Massive MIMO Networks
This paper proposes a new power control and pilot allocation scheme for
device-to-device (D2D) communication underlaying a multi-cell massive MIMO
system. In this scheme, the cellular users in each cell get orthogonal pilots
which are reused with reuse factor one across cells, while the D2D pairs share
another set of orthogonal pilots. We derive a closed-form capacity lower bound
for the cellular users with different receive processing schemes. In addition,
we derive a capacity lower bound for the D2D receivers and a closed-form
approximation of it. Then we provide a power control algorithm that maximizes
the minimum spectral efficiency (SE) of the users in the network. Finally, we
provide a numerical evaluation where we compare our proposed power control
algorithm with the maximum transmit power case and the case of conventional
multi-cell massive MIMO without D2D communication. Based on the provided
results, we conclude that our proposed scheme increases the sum spectral
efficiency of multi-cell massive MIMO networks.Comment: 6 Pages, 3 Figures, WSA 201
Does Microcredit Reach the Poor and Vulnerable? Evidence from Northern Bangldesh.
The Grameen Bank's success in Bangladesh has made microcredit the hot new idea for reducing poverty. This paper uses panel data from two Bangladeshi villages to test if loan recipients are poorer and more vulnerable than non-recipients. Poverty is measured by levels of consumption. Vulnerablitiy is measured as fluctuations in consumption (associated with inefficient risk sharing). We find that loan recipients are poorer than non-recipients in both villages, but are more vulnerable than non-recipients only in the richer and more diversified village. Though microcredit programs target the landless, there is substantial leakage to the landed. Landlessness is not significangly associated with either poverty or vulnerablitiy, but female headship is. Female headed households may be a more appropriate target group for anti-poverty credit programs.POVERTY ; RISK ; ECONOMIC GROWTH
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