5,978 research outputs found

    An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

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    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

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    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.

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    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

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    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

    A Comparative Study of Some Cellular Manufacturing Techniques

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    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.

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    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

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    We study the diffusion of influence in random multiplex networks where links can be of rr different types, and for a given content (e.g., rumor, product, political view), each link type is associated with a content dependent parameter cic_i in [0,][0,\infty] that measures the relative bias type-ii 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 mim_i active neighbors and kimik_i-m_i inactive neighbors via type-ii links will turn active if cimi/ciki\sum{c_i m_i}/\sum{c_i k_i} 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

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    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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