1,391 research outputs found
Nearest Neighbor and Contact Distance Distribution for Binomial Point Process on Spherical Surfaces
This letter characterizes the statistics of the contact distance and the
nearest neighbor (NN) distance for binomial point processes (BPP)
spatially-distributed on spherical surfaces. We consider a setup of
concentric spheres, with each sphere has a radius and points
that are uniformly distributed on its surface. For that setup, we obtain the
cumulative distribution function (CDF) of the distance to the nearest point
from two types o observation points: (i) the observation point is not a part of
the point process and located on a concentric sphere with a radius
, which corresponds to the contact distance distribution, and
(ii) the observation point belongs to the point process, which corresponds to
the nearest-neighbor (NN) distance distribution
Genetic variation of durum wheat landraces using morphological and protein markers
Genetic variations of cultivars are very interesting in reducing genetic vulnerability and lead to stable control of production. The aim of this research was to study genetic diversity among six durum wheat cultivars. For the first assay we evaluated seven morphological traits which are: spikelet per spike, spike length, spike width, beard length, plant height, width of truncation and barb length. The tested genotypes were classified in three groups according to the linkage distance analysis. The genetic variability was also evaluated for seed storage-proteins by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE). Electrophoregram allowed the estimation of the durum wheat genetic similarity (GS). This GS analysis based on Unweighted Pair Group Method with Arithmetic averages (UPGMA), permits to obtain the same genotypic clustering. No significant correlation was observed among the two methods tested. It is concluded that seed storage protein profiles could be useful markers in the studies of genetic diversity and genotypes classification, which can be used to improve the efficiency of wheat breeding programs.Key words: Wheat genotypes, SDS-PAGE, genetic diversity, cluster analysis
On the Effect of Correlated Measurements on the Performance of Distributed Estimation
We address the distributed estimation of an unknown scalar parameter in
Wireless Sensor Networks (WSNs). Sensor nodes transmit their noisy observations
over multiple access channel to a Fusion Center (FC) that reconstructs the
source parameter. The received signal is corrupted by noise and channel fading,
so that the FC objective is to minimize the Mean-Square Error (MSE) of the
estimate. In this paper, we assume sensor node observations to be correlated
with the source signal and correlated with each other as well. The correlation
coefficient between two observations is exponentially decaying with the
distance separation. The effect of the distance-based correlation on the
estimation quality is demonstrated and compared with the case of unity
correlated observations. Moreover, a closed-form expression for the outage
probability is derived and its dependency on the correlation coefficients is
investigated. Numerical simulations are provided to verify our analytic
results.Comment: 5 page
What is the mechanism of prolonged ileus after colectomy for inflammatory bowel disease within the ERAS protocol?
International audienc
Polynomial Chaos Expansion method as a tool to evaluate and quantify field homogeneities of a novel waveguide RF Wien Filter
For the measurement of the electric dipole moment of protons and deuterons, a
novel waveguide RF Wien filter has been designed and will soon be integrated at
the COoler SYnchrotron at J\"ulich. The device operates at the harmonic
frequencies of the spin motion. It is based on a waveguide structure that is
capable of fulfilling the Wien filter condition ()
\textit{by design}. The full-wave calculations demonstrated that the waveguide
RF Wien filter is able to generate high-quality RF electric and magnetic
fields. In reality, mechanical tolerances and misalignments decrease the
simulated field quality, and it is therefore important to consider them in the
simulations. In particular, for the electric dipole moment measurement, it is
important to quantify the field errors systematically. Since Monte-Carlo
simulations are computationally very expensive, we discuss here an efficient
surrogate modeling scheme based on the Polynomial Chaos Expansion method to
compute the field quality in the presence of tolerances and misalignments and
subsequently to perform the sensitivity analysis at zero additional
computational cost.Comment: 12 pages, 19 figure
Exploiting Randomly-located Blockages for Large-Scale Deployment of Intelligent Surfaces
One of the promising technologies for the next generation wireless networks
is the reconfigurable intelligent surfaces (RISs). This technology provides
planar surfaces the capability to manipulate the reflected waves of impinging
signals, which leads to a more controllable wireless environment. One potential
use case of such technology is providing indirect line-of-sight (LoS) links
between mobile users and base stations (BSs) which do not have direct LoS
channels. Objects that act as blockages for the communication links, such as
buildings or trees, can be equipped with RISs to enhance the coverage
probability of the cellular network through providing extra indirect LoS-links.
In this paper, we use tools from stochastic geometry to study the effect of
large-scale deployment of RISs on the performance of cellular networks. In
particular, we model the blockages using the line Boolean model. For this
setup, we study how equipping a subset of the blockages with RISs will enhance
the performance of the cellular network. We first derive the ratio of the
blind-spots to the total area. Next, we derive the probability that a typical
mobile user associates with a BS using an RIS. Finally, we derive the
probability distribution of the path-loss between the typical user and its
associated BS. We draw multiple useful system-level insights from the proposed
analysis. For instance, we show that deployment of RISs highly improves the
coverage regions of the BSs. Furthermore, we show that to ensure that the ratio
of blind-spots to the total area is below 10^5, the required density of RISs
increases from just 6 RISs/km2 when the density of the blockages is 300
blockage/km^2 to 490 RISs/km^2 when the density of the blockages is 700
blockage/km^2.Comment: Accepted in IEEE Journal on Selected Areas in Communication
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