A Low Cost and Low Power Consumption Automatic Water Meter Reading System: Hardware Investigation and Network Design

This paper presents a low power consumption and low cost automatic data collection network for water meter application. Based on transmission performance and power consumption, several low cost sub-GHz wireless transceivers are analyzed and compared, and consequently a suitable hardware is chosen. The associated network protocol stack is also examined. To construct the automatic collecting data mechanism, we consider a cluster based wireless sensor network (WSN) where routers and a GPRS gateway are used to link each cluster to a data collection center. Advantages of this proposed configuration are the simple implementation, low cost and low power consumption. By using the Monte Carlo simulation technique, packet delivery ratio and power consumption for different topologies are investigated. Based on obtained results, the optimum network topology for automatic water meter reading in a typical urban environment is finally proposed

Development of a preliminary high-angle-of-attack nose-down pitch control requirement for high-performance aircraft

The requirements for high-angle-of-attack nose-down pitch control for advanced high-performance aircraft are discussed. Background information on fundamental factors that influence and, to a large extent, determine the high angle-of-attack nose-down control requirement is briefly reviewed. Guidelines currently proposed by other sources which attempt to define these requirements are discussed. A requirement based on NASA analysis of the characteristics of existing relaxed static stability (RSS) aircraft is presented. This analysis could provide the basis for a preliminary design guide

FFT simulations and multi-coated inclusion model for macroscopic conductivity of 2D suspensions of compound inclusions

Article introduces the Fast-Fourier transformation method (FFT) and an approximation method to calculate the conductivity of compound-inclusion composites in two-dimensional space. The approximation compares favorably with the numerical results for a number of periodic and random models over a range of volume proportions of phases, but divers at large volume proportions of the included phases when the interactions between the inclusions are more pronounced

Cell membrane array fabrication and assay technology

BACKGROUND: Microarray technology has been used extensively over the past 10 years for assessing gene expression, and has facilitated precise genetic profiling of everything from tumors to small molecule drugs. By contrast, arraying cell membranes in a manner which preserves their ability to mediate biochemical processes has been considerably more difficult. RESULTS: In this article, we describe a novel technology for generating cell membrane microarrays for performing high throughput biology. Our robotically-arrayed supported membranes are physiologically fluid, a critical property which differentiates this technology from other previous membrane systems and makes it useful for studying cellular processes on an industrialized scale. Membrane array elements consist of a solid substrate, above which resides a fluid supported lipid bilayer containing biologically-active molecules of interest. Incorporation of transmembrane proteins into the arrayed membranes enables the study of ligand/receptor binding, as well as interactions with live intact cells. The fluidity of these molecules in the planar lipid bilayer facilitates dimerization and other higher order interactions necessary for biological signaling events. In order to demonstrate the utility of our fluid membrane array technology to ligand/receptor studies, we investigated the multivalent binding of the cholera toxin B-subunit (CTB) to the membrane ganglioside GM(1). We have also displayed a number of bona fide drug targets, including bacterial endotoxin (also referred to as lipopolysaccharide (LPS)) and membrane proteins important in T cell activation. CONCLUSION: We have demonstrated the applicability of our fluid cell membrane array technology to both academic research applications and industrial drug discovery. Our technology facilitates the study of ligand/receptor interactions and cell-cell signaling, providing rich qualitative and quantitative information

Risk factors of dengue fever in an urban area in Vietnam: a case-control study

BackgroundDengue is a mosquito-borne flavivirus present in many metropolitan cities of tropical countries.MethodsDuring and after the dengue season (September 2018 to January 2019), we conducted a case-control study in order to determine the risk factors for dengue fever in Hanoi city, Vietnam. 98 dengue patients and 99 patients with other acute infections, such as Hepatitis B virus infection, were recruited at Department of Infectious Disease of Bach Mai national hospital in Hanoi. Patients were interviewed using a structured questionnaire covering demographic, housing, environmental factors and knowledge, attitude, and practice on dengue prevention and control. Univariate analysis and multivariable logistic regression were used to determine the risk factors of dengue status.ResultsThe mean score of knowledge items and practice items was only 7.9 out of total 19 points and 3.9 out of total 17 points, respectively. While the mean score of attitude items was 4.8 out of total 6 points. Multivariable logistic regression indicated that older patients had lesser risk of getting dengue infection as compared to younger adults aged 16-30, and patients living in peri-urban districts were less likely to suffer of dengue fever than patients living in central urban districts (OR=0.31; 95% CI 0.13-0.75). This study could not find any association with occupation, water storage habit, knowledge, attitude, or practice on dengue prevention.ConclusionsAll patients had a relatively low level of knowledge and practice on dengue prevention and control. However, the attitude of the participants was good. We found that age group and living district were the risk factors correlated with the dengue status. Communication programs on raising dengue awareness should be repeated all year round and target particular groups of adolescents, younger adults, landlords and migrants from other provinces to improve their knowledge and encourage them to implement preventive measures against dengue fever

Maternal Lifestyle, Gestational Diabetes Mellitus and Pregnancy Outcomes: A Prospective Cohort Study in Vietnam

A prospective cohort study was conducted in Vietnam to assess maternal lifestyle, gestational diabetes mellitus, and pregnancy outcomes. The study showed that the majority of pregnant women did not meet the recommendations for essential nutrients and physical activity during pregnancy. The prevalence of gestational diabetes was high and varied substantially according to diagnostic criteria. Caesarean section and macrosomia were the main adverse pregnancy outcomes that were more prevalent among women with gestational diabetes

Apports de la théorie de l'information et de l'échantillonnage compressé pour la surveillance de spectre

This thesis aims to exploit the state-of-art of the Modulated Wideband Converter (MWC) and Compressed Sensing (CS) technology, to monitor and detect a wideband spectrum, without any knowledge of the input signal and its frequency support.A prototype of compressed sensing based on the MWC scheme and developed by the CACS/COM team of Lab-STICC is briefly introduced.Addressing the impacts of analog components imperfections on the MWC output, then proposing solution to overcome them by studying each component independently, are the main objectives of this thesis. A digital post-processing scheme with amplitude and phase compensation is proposed and applied after real lowpass filtering step to achieve the filtered output as close as the ideal one.Then, several real types of Analog-to-Digital Converter (ADC) with low-bit quantization are presented and combined to the MWC in simulation.The results of spectrum reconstruction are then evaluated with respect to a proposed criterion of correct reconstruction rate and false alarm rate. This thesis goes on dealing with the influence of wideband signal key parameters (frequency resolution, bandwidths, etc.) on its spectrum reconstruction, especially for Internet-of-Things (IoT) applications.Cette thèse a pour but d’exploiter l’état de l’art du Modulated Wideband Converter (MWC) et de l’acquisition compressée afin de surveiller et de détecter un spectre radiofréquence large bande, sans aucune connaissance a priori du signal d’entrée et de son support fréquentiel. Un prototype d’échantillonnage compressé basé sur le MWC développé par l’équipe CACS/COM du Lab-STICC est brièvement présenté. Les principaux objectifs de cette thèse sont d’identifier l’impact des composants analogiques du prototype sur les sorties du MWC et de proposer des solutions afin de corriger les défauts de chaque composant indépendamment des autres. Une méthode de compensation numérique en amplitude et en phase est proposée et appliquée après l’étape de filtrage passe-bas pour obtenir une sortie proche du filtre passe-bas idéal. Ensuite, plusieurs types de convertisseurs analogiques numériques faible nombre de bits ont été recensés et combinés au MWC en simulation. Les résultats de reconstruction spectrale sont ensuite évalués à partir des taux de bonne reconstruction et de fausse alarme. Cette thèse aborde également l’influence des paramètres clés d’un signal large bande (résolution fréquentielle, largeur de bande, etc.) sur la reconstruction spectrale, notamment pour des applications de l’Internet des Objets (IoT)

Maximum power point tracking for a photovoltaic power system

193 p.This dissertation proposes a novel maximum power point tracking (MPPT) algorithm that works optimally for a photovoltaic system under fast changing temperature and irradiation conditions. The new approach can effectively improve the tracking speed and accuracy simultaneously, which is the contradiction in conventional methods such as P&O or INC. This is particularly important for photovoltaic systems that frequently experience rapidly changing environmental conditions.MASTER OF ENGINEERING (EEE