5,978 research outputs found
An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency
In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna
Participatory plant breeding: a way to arrive at better-adapted onion varieties
The search for varieties that are better adapted to organic farming is a current topic in the organic sector. Breeding programmes specific for organic agriculture should solve this problem. Collaborating with organic farmers in such programmes, particularly in the selection process, can potentially result in varieties better adapted to their needs. Here, we assume that organic farmers' perceptive of plant health is broader than that of conventional breeders. Two organic onion farmers and one conventional onion breeder were monitored in their selection activities in 2004 and 2005 in order to verify whether and in which way this broader view on plant health contributes to improvement of organic varieties.
They made selections by positive mass selection in three segregating populations under organic conditions. The monitoring showed that the organic farmers selected in the field for earliness and downy mildew and after storage for bulb characteristics. The conventional breeder selected only after storage. Farmers and breeder applied identical selection directions for bulb traits as a round shape, better hardness and skin firmness. This resulted in smaller bulbs in the breeders’ populations, while the bulbs in the farmer populations were bigger than in the original population. In 2006 and 2007 the new onion populations will be compared with each other and the original populations to determine the selection response
3D Object Recognition Using Multiple Views And Neural Networks.
This paper proposes a method for recognition and classification of 3D objects. The method is based on 2D moments and neural networks. The 2D moments are calculated based on 2D intensity images taken from multiple cameras that have been arranged using multiple views technique. 2D moments are commonly used for 2D pattern recognition
Comparative study ofthe computational fluid dynamics and fluid structure interaction analysis in human airways flow
Numerous studies have been done in order to get the most accurate result that represents the flow characteristics inside the human trachea. Numerical method was the most favorite type of study chosen to simulate the model due to the complexity of the geometry and difficulties to get the real trachea to do the experimental works. In this study, one actual healthy model of human trachea was reconstructed in order to compare, the different of the velocity and pressure distribution between two types of numerical modeling analysis: Computational Fluid Dynamics (CFD) and Fluid Structure Interaction (FSI) analysis. The model was extracted using the Computed Tomography (CT) scan images to maintain the realistic geometry. Velocity, 1.24 m/s was used at the inlet and the variations of the velocity and pressure distribution along the trachea were observed. The results shown that, the implementation of the FSI technique did produce different result and flexibility of the structure wall did influence the distribution of the velocity and pressure along the trachea
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Storyline description of Southern Hemisphere midlatitude circulation and precipitation response to greenhouse gas forcing
As evidence of climate change strengthens, knowledge of its regional implications becomes an urgent need for decision making. Current understanding of regional precipitation changes is substantially limited by our understanding of the atmospheric circulation response to climate change, which to a high degree remains uncertain. This uncertainty is reflected in the wide spread in atmospheric circulation changes projected in multimodel ensembles, which cannot be directly interpreted in a probabilistic sense. The uncertainty can instead be represented by studying a discrete set of physically plausible storylines of atmospheric circulation changes. By mining CMIP5 model output, here we take this broader perspective and develop storylines for Southern Hemisphere (SH) midlatitude circulation changes, conditioned on the degree of global-mean warming, based on the climate responses of two remote drivers: the enhanced warming of the tropical upper troposphere and the strengthening of the stratospheric polar vortex. For the three continental domains in the SH, we analyse the precipitation changes under each storyline. To allow comparison with previous studies, we also link both circulation and precipitation changes with those of the Southern Annular Mode. Our results show that the response to tropical warming leads to a strengthening of the midlatitude westerly winds, whilst the response to a delayed breakdown (for DJF) or strengthening (for JJA) of the stratospheric vortex leads to a poleward shift of the westerly winds and the storm tracks. However, the circulation response is not zonally symmetric and the regional precipitation storylines for South America, South Africa, South Australia and New Zealand exhibit quite specific dependencies on the two remote drivers, which are not well represented by changes in the Southern Annular Mode
A Comparative Study of Some Cellular Manufacturing Techniques
Cellular manufacturing (CM) is a concept that involves processing of similar parts on
dedicated cluster (or cells) of dissimilar machines or manufacturing processes. This
paper concentrated on seven cell formation techniques used in Cellular Manufacturing
(CM). The techniques were used to develop cells for matrices from various sizes of parts
and machines. By randomly rearranging the sequence of the machines in the reference
matrices (cited from published journals), 12 new matrices were developed. This paper
also concentrated on performing the treatments for bottleneck, exceptional elements or
voids using part subcontracting or machine duplication for the developed cells. The
performance of each technique was measured using Grouping Measures (GM), where
high percentage of GM indicates that the technique has high machine utilization (MU)
and low percentage of exceptional elements (EE). Overall, Bond Energy Algorithm
(BEA) was found to be the best cell formation technique
Cl415, a carbapenem-resistant Acinetobacter baumannii isolate containing four AbaR4 and a new variant of AbGRI2, represents a novel global clone 2 strain.
ObjectivesTo determine the genetic context of genes conferring antibiotic resistance on the carbapenem-resistant Acinetobacter baumannii Cl415, recovered in 2017 at El Youssef Hospital Centre in Akkar Governorate, North Lebanon.MethodsAntibiotic resistance phenotype for 22 antibiotics was determined using disc diffusion or MIC determination. The whole-genome sequence of Cl415 was determined using a combination of the Illumina MiSeq and Oxford Nanopore (MinION) platforms. Complete genome was assembled using Unicycler and antibiotic resistance determinants and ISs were identified using ResFinder and ISFinder, respectively.ResultsCl415 is a global clone 2 (GC2) strain and belongs to the most common STs of this clone, ST2IP and ST218OX. Cl415 is resistant to several antibiotics, including aminoglycosides and carbapenems to a high level. Genomic analysis of Cl415 revealed that it carries four chromosomal AbaR4 copies. One copy was found in the comM gene replacing the AbGRI1 island. Cl415 also contains a novel variant of AbGRI2, herein called AbGRI2-15, carrying only the blaTEM and aphA1 resistance genes. Cl415 belongs to a subclade of GC2 strains that appear to have diverged recently with a wide geographical distribution.ConclusionsThe resistance gene complement of Cl415 was found in the chromosome with four oxa23 located in AbaR4 copies and the remaining genes in a novel variant of the AbGRI2 resistance island. Cl415 was isolated in Lebanon, but phylogenetic analysis suggests that Cl415 represents a new lineage with global distribution within GC2
Analysis of complex contagions in random multiplex networks
We study the diffusion of influence in random multiplex networks where links
can be of different types, and for a given content (e.g., rumor, product,
political view), each link type is associated with a content dependent
parameter in that measures the relative bias type- links
have in spreading this content. In this setting, we propose a linear threshold
model of contagion where nodes switch state if their "perceived" proportion of
active neighbors exceeds a threshold \tau. Namely, a node connected to
active neighbors and inactive neighbors via type- links will turn
active if exceeds its threshold \tau. Under this
model, we obtain the condition, probability and expected size of global
spreading events. Our results extend the existing work on complex contagions in
several directions by i) providing solutions for coupled random networks whose
vertices are neither identical nor disjoint, (ii) highlighting the effect of
content on the dynamics of complex contagions, and (iii) showing that
content-dependent propagation over a multiplex network leads to a subtle
relation between the giant vulnerable component of the graph and the global
cascade condition that is not seen in the existing models in the literature.Comment: Revised 06/08/12. 11 Pages, 3 figure
Neonatal Outcomes in Type 1 Diabetes Pregnant Women, A Single-Center Retrospective Study
Background: Pregnancy in women with type 1 diabetes mellitus (T1DM) is associated with an increased risk of congenital malformations, and obstetric complications including increased rates of cesarean section birth, prematurity, and neonatal adverse outcomes including large for gestational age (LAG), and hypoglycemia. Our aim of this study is to investigate and evaluate the prevalence and the different neonatal outcomes of T1DM pregnant women compared to nondiabetic healthy pregnant women in a single-center experience to improve the effectiveness of interventions for the treatment of pregnant women with T1DM.
Methods: This is a retrospective cohort study of 113 pregnant women (43 pregnant patients with T1DM and 70 non-diabetic healthy pregnant women) who underwent regular follow-in the antenatal period and delivered at King Fahad Military Medical Complex (KMMC) - Dhahran between 2018 and 2023.
Results: A total of 117 pregnant women (47 with Type-1 diabetes mellitus-T1DM and 70 healthy controls) were included in the study. The proportion of elective C-sections was significantly high in women with T1DM 21 (44.7%) and the proportion of neonatal hypoglycemia who need treatment was also significantly high in diabetic women 20 (42.6%). NICU/SCBU admission was significantly high in diabetic women 23 (48.9%).
Conclusion: The high prevalence of neonatal adverse outcomes especially hypoglycemia and intensive care admission of T1DM pregnant women compared to non-diabetic pregnant women indicates that this model of antenatal diabetes care must be improved to enhance maternal and fetal outcomes, especially in such high-risk groups and challenging problems
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