Neural Networks for Synthesis and Optimization of Antenna Arrays

This paper describes a usual application of back-propagation neural networks for synthesis and optimization of antenna array. The neural network is able to model and to optimize the antennas arrays, by acting on radioelectric or geometric parameters and by taking into account predetermined general criteria. The neural network allows not only establishing important analytical equations for the optimization step, but also a great flexibility between the system parameters in input and output. This step of optimization becomes then possible due to the explicit relation given by the neural network. According to different formulations of the synthesis problem such as acting on the feed law (amplitude and/or phase) and/or space position of the radiating sources, results on antennas arrays synthesis and optimization by neural networks are presented and discussed. However ANN is able to generate very fast the results of synthesis comparing to other approaches

Microstrip antennas array Design Using Genetic algorithms and Simulated Annealing

This publication presents two new approaches of design microstrip antennas array. First is based on the technique of the genetic algorithms inspired from the processes of the evolution of the species and the natural genetics and the second based on the analogy between the resolution of the combinative problems of optimization and the annealing of the solids. These two approaches permits to seek simultaneous the law of optimal feed and the space distribution of the radiant elements so that the radiation pattern is as close as possible to an optimal desired diagram specified from a function or a pattern shape.Cette publication présente deux nouvelles approches de conception de réseaux d'antennes imprimées. La première est basée sur la technique des algorithmes génétiques inspirée des processus de l'évolution des espèces et de la génétique naturelle et la deuxième sur l'analogie entre la résolution des problèmes d'optimisation combinatoire et le recuit des solides. Ces deux approches permettent de rechercher simultanément la loi d'alimentation optimale et la répartition spatiale des éléments rayonnants pour que le diagramme de directivité du réseau soit aussi proche que possible d'un diagramme désiré optimal spécifié à partir d'une fonction ou d'un gabarit

Electronic structure of wurtzite and zinc-blende AlN

The electronic structure of AlN in wurtzite and zinc-blende phases is studied experimentally and theoretically. By using x-ray emission spectroscopy, the Al 3p, Al 3s and N 2p spectral densities are obtained. The corresponding local and partial theoretical densities of states (DOS), as well as the total DOS and the band structure, are calculated by using the full potential linearized augmented plane wave method, within the framework of the density functional theory. There is a relatively good agreement between the experimental spectra and the theoretical DOS, showing a large hybridization of the valence states all along the valence band. The discrepancies between the experimental and theoretical DOS, appearing towards the high binding energies, are ascribed to an underestimation of the valence band width in the calculations. Differences between the wurtzite and zinc-blende phases are small and reflect the slight variations between the atomic arrangements of both phases

ONTOLOGY-BASED WEB TOOLS for RETRIEVING PHOTOGRAMMETRIC CULTURAL HERITAGE MODELS

International audienc

Логистическая координация транспортировки нефтепродуктов

Данная работа посвящена разработке направления оптимизации логистических процессов на предприятии АО "Томскнефть" ВНК на основе теоретического и практического опыта. В результате поведенного исследования были рассмотрены теоретические основы организации логистических процессов, проанализирована логистическая деятельность предприятия АО "Томскнефть" ВНК и разработаны направления совершенствования логистического процесса материального обеспечения АО "Томскнефть" ВНК.This work is devoted to the development of logistics optimization processes at the enterprise JSC Tomskneft VNK on the basis of theoretical and practical experience. As a result of the conducted research, the theoretical foundations of the organization of logistics processes were considered, the logistics activities of the enterprise JSC were analyzed Tomskneft VNK and developed areas for improving the logistics process material security JSC Tomskneft VNK

Immune responses during COVID-19 infection

Over the past 16 years, three coronaviruses (CoVs), severe acute respiratory syndrome CoV (SARS-CoV) in 2002, Middle East respiratory syndrome CoV (MERS-CoV) in 2012 and 2015, and SARS-CoV-2 in 2020, have been causing severe and fatal human epidemics. The unpredictability of coronavirus disease-19 (COVID-19) poses a major burden on health care and economic systems across the world. This is caused by the paucity of in-depth knowledge of the risk factors for severe COVID-19, insufficient diagnostic tools for the detection of SARS-CoV-2, as well as the absence of specific and effective drug treatments. While protective humoral and cellular immune responses are usually mounted against these betacoronaviruses, immune responses to SARS-CoV2 sometimes derail towards inflammatory tissue damage, leading to rapid admissions to intensive care units. The lack of knowledge on mechanisms that tilt the balance between these two opposite outcomes poses major threats to many ongoing clinical trials dealing with immunostimulatory or immunoregulatory therapeutics. This review will discuss innate and cognate immune responses underlying protective or deleterious immune reactions against these pathogenic coronaviruses

Antidiabetic treatment, obesity, and cancer risk in Algerian patients with type 2 diabetes mellitus

OBJECTIVE: Several studies have shown that antidiabetic drugs and obesity can modulate the risk of developing cancer. The objective of this study was to assess the impact of the use of antidiabetic drugs and obesity on the risk of developing cancers in type 2 diabetics. MATERIALS AND METHODS: Data for 1220 patients were collected from the processing of files and a pre-established questionnaire. The anthropobiological parameters and the associated treatment type have been unspecified. RESULTS: Women (OR=17.26; 95% CI=2.88-103.45, p<0.01), overweight individuals (OR=4.81; 95% CI=1.63-14.14, p<0.01) and hypertensive diabetic subjects (OR=3.82; 95% CI=1.39-10.49, p< 0.01) are more exposed to cancers. It is interesting to note that diabetic subjects treated with insulin have a reduced risk of developing cancer (OR=0.22; 95% CI=0.07-0.67, p<0.01). Diabetic subjects treated with metformin have a four and a half times higher risk of developing cancer (OR=4.61; 95% CI=1.48-14.37, p<0.01). CONCLUSIONS: In type 2 diabetic subjects, cancer is significantly linked to overweight, to the presence of essential hypertension in individuals under hypotensive as well as in patients treated with metformin

Circulating senescent myeloid cells drive blood brain barrier breakdown and neurodegeneration

Neurodegenerative diseases (ND) are characterized by progressive loss of neuronal function. Mechanisms of ND pathogenesis are incompletely understood, hampering the development of effective therapies. Langerhans cell histiocytosis (LCH) is an inflammatory neoplastic disorder caused by hematopoietic progenitors expressing MAPK activating mutations that differentiate into senescent myeloid cells that drive lesion formation. Some patients with LCH subsequently develop progressive and incurable neurodegeneration (LCH-ND). Here, we show that LCH-ND is caused by myeloid cells that are clonal with peripheral LCH cells. We discovered that circulating BRAF V600E $^{+}$ myeloid cells cause the breakdown of the blood-brain barrier (BBB), enhancing migration into the brain parenchyma where they differentiate into senescent, inflammatory CD11a $^{+}$ macrophages that accumulate in the brainstem and cerebellum. Blocking MAPK activity and senescence programs reduced parenchymal infiltration, neuroinflammation, neuronal damage and improved neurological outcome in preclinical LCH-ND. MAPK activation and senescence programs in circulating myeloid cells represent novel and targetable mechanisms of ND

Decision process in large-scale crisis management

International audienceThis paper deals with the decision-aiding process in large-scale crisis such as natural disasters. It consists in four phases: decision context characterization, system modelling, aggregation and integration. The elements of the context, such as crisis level, risk situation, decision-maker problem issue are defined through the characterization phase. At the feared event occurrence, these elements will interact on a target system. Through the model on this system, the consequences to stakes could be assessed or estimated. The presented aggregation approaches will allow taking the right decisions. The architecture of a Decision Support System is presented in the integration phase

Quantum Smoluchowski equation: Escape from a metastable state

We develop a quantum Smoluchowski equation in terms of a true probability distribution function to describe quantum Brownian motion in configuration space in large friction limit at arbitrary temperature and derive the rate of barrier crossing and tunneling within an unified scheme. The present treatment is independent of path integral formalism and is based on canonical quantization procedure.Comment: 10 pages, To appear in the Proceedings of Statphys - Kolkata I