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Dissertation
Détermination de positions précises à l'aide des données bifréquence issues de smartphones
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Year: 2019 Publisher: Liège Université de Liège (ULiège)

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Tous les smartphones sont capables de calculer leur position grâce à une puce GNSS. Actuellement, de nombreuses applications exploitent ce positionnement, même si sa précision et son exactitude peuvent être décamétriques (Zhang et al., 2018). Réussir à obtenir un positionnement de meilleure qualité aurait un impact sur l’économie mondiale (Humphreys et al., 2016).
Depuis mai 2016, les données brutes provenant des récepteurs GNSS des smartphones sont disponibles (GSA, 2018). Cet accès a permis de nombreuses améliorations en termes de précision et d’exactitude des positions. 
En mai 2018, la société chinoise Xiaomi a sorti le premier smartphone possédant un récepteur bifréquence : le Xiaomi Mi 8 (Xiaomi, 2018).
Ce travail a pour objectif d’estimer la qualité des observables et le gain en précision et en exactitude qu’il est possible d’obtenir en utilisant un smartphone nouvelle génération possédant une puce GNSS bifréquence (L1-L5/E1-E5) comme le Xiaomi Mi 8. 
La méthodologie utilisée est réalisée dans trois environnements différents : une cage de Faraday connectée à une antenne géodésique, le toit du bâtiment B5a de l’Université de Liège sur le campus du Sart-Tilman et un jardin de la commune de Neupré.
La qualité des observables est obtenue en réalisant des doubles différences et appliquant la loi de la propagation des erreurs.
Les performances du récepteur bifréquence du Xiaomi Mi 8 sont évaluées en comparant les positions calculées par ce récepteur et par ceux du Samsung S8 et de l’Huawei Mate 20 Pro.
Le gain en précision et en exactitude du positionnement avec les données brutes est obtenu en appliquant sur ces données mono et bifréquences différentes techniques de positionnement (Single Point Positioning (SPP), positionnement différentiel (DGNSS) et positionnement relatif) à l’aide du logiciel RTKLib.
Les résultats obtenus permettent de conclure que les observables du Xiaomi Mi 8 sont significativement plus précises que celles des smartphones d’anciennes générations. Cela est en partie lié à la capacité du récepteur à gérer la fréquence L5/E5. Les phases ont une précision de l’ordre du centimètre. Les codes, plus sensibles au multitrajet, ont une précision entre 0,10 et 10 mètres selon l’environnement.
En utilisant le logiciel RTKLib, l’apport de la deuxième fréquence n’améliore pas de manière significative les résultats de positionnement. Il peut même parfois les dégrader. Cependant, l’accès aux données brutes du Xiaomi Mi 8 permet d’obtenir, dans certains environnements, des positions ayant une précision et une exactitude centimétriques. 
Certaines limitations induites par la méthode, les expériences et le logiciel RTKLib sont à prendre en considération lors de l’analyse de ces résultats. All smartphones are able to calculate their position thanks to a GNSS chip. Currently, many applications exploit this positioning, even if its precision and accuracy can be decametric (Zhang et al., 2018). Achieving better quality positioning would have an impact on the global economy (Humphreys et al., 2016). 
Since May 2016, raw data from the GNSS receivers of smartphones are available (GSA, 2018). This access has enabled many improvements in terms of precision and accuracy of positions. In May 2018, the Chinese company Xiaomi released the first Smartphone with a dual frequency receiver: the Xiaomi MI 8 (Xiaomi, 2018).
The objective of this work is to estimate the quality of the observables and the gain in precision and accuracy that can be obtained by using a new generation Smartphone with a dual-frequency GNSS chip (L1-L5/E1-E5) such as the Xiaomi MI 8. 
The methodology used is carried out in three different environments: a RF-shielded box connected to a geodetic antenna, the roof of the B5a building of the University of Liège on the Sart-Tilman campus and a garden of the Neupré municipality. 
The quality of the observables is obtained by performing double differences and applying the law of the error propagation. The performance of the Xiaomi MI 8 dual frequency receiver is evaluated by comparing the positions calculated by this receiver and those of the Samsung S8 and Huawei mate 20 Pro. The gain in precision and accuracy of the positioning with the raw data is obtained by applying, on mono and dual-frequency raw data, different positioning techniques (single point positioning (SPP), differential positioning (DGNSS) and relative positioning) using the RTKLib software. 
The results obtained allow to conclude that the observables of Xiaomi MI 8 are significantly more accurate than those of older generation smartphones. This is partly related to the receiver's ability to manage the L5/E5 frequency. The phases have precision of the order of the centimetre. The codes, more sensitive to multipath, have a precision between 0,10 and 10 meters depending on the environment.
Using the RTKLib software, the input of the second frequency does not significantly improve the positioning results. It can even degrade them sometimes. However, access to the raw data of the Xiaomi MI 8 allows to obtain positions with centimetric precision and accuracy depending on the environment. Some limitations induced by the method, the experiments and the RTKLib software must be taken into consideration when analyzing these results.


Book
Liquid Crystal Optical Device
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ISBN: 3039280570 3039280562 Year: 2020 Publisher: MDPI - Multidisciplinary Digital Publishing Institute

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Abstract

The Special Issue “Liquid Crystal Optical Devices” discusses recent developments in the rapidly advancing subject of liquid crystals (LCs).


Book
The Applications of Plasma Techniques II
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Year: 2022 Publisher: Basel MDPI - Multidisciplinary Digital Publishing Institute

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The collection of articles discussed above covers various types of discharges and various processes. The discharges presented include, for example, microwave, spark, glow or surface discharges. The characterizations of the sources of these discharges, the parameters of the generated plasmas as well as the applications of these plasmas are discussed. The applications include, for example, the synthesis of nanoparticles or the treatment of skin cancer cells. I hope that the presented articles will be valuable for readers representing the world of science, medicine and technology.


Book
The Applications of Plasma Techniques II
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Year: 2022 Publisher: Basel MDPI - Multidisciplinary Digital Publishing Institute

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Abstract

The collection of articles discussed above covers various types of discharges and various processes. The discharges presented include, for example, microwave, spark, glow or surface discharges. The characterizations of the sources of these discharges, the parameters of the generated plasmas as well as the applications of these plasmas are discussed. The applications include, for example, the synthesis of nanoparticles or the treatment of skin cancer cells. I hope that the presented articles will be valuable for readers representing the world of science, medicine and technology.


Book
The Applications of Plasma Techniques II
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Year: 2022 Publisher: Basel MDPI - Multidisciplinary Digital Publishing Institute

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Abstract

The collection of articles discussed above covers various types of discharges and various processes. The discharges presented include, for example, microwave, spark, glow or surface discharges. The characterizations of the sources of these discharges, the parameters of the generated plasmas as well as the applications of these plasmas are discussed. The applications include, for example, the synthesis of nanoparticles or the treatment of skin cancer cells. I hope that the presented articles will be valuable for readers representing the world of science, medicine and technology.


Book
Microwave Indices from Active and Passive Sensors for Remote Sensing Applications
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ISBN: 3038978213 3038978205 Year: 2019 Publisher: MDPI - Multidisciplinary Digital Publishing Institute

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Past research has comprehensively assessed the capabilities of satellite sensors operating at microwave frequencies, both active (SAR, scatterometers) and passive (radiometers), for the remote sensing of Earth’s surface. Besides brightness temperature and backscattering coefficient, microwave indices, defined as a combination of data collected at different frequencies and polarizations, revealed a good sensitivity to hydrological cycle parameters such as surface soil moisture, vegetation water content, and snow depth and its water equivalent. The differences between microwave backscattering and emission at more frequencies and polarizations have been well established in relation to these parameters, enabling operational retrieval algorithms based on microwave indices to be developed. This Special Issue aims at providing an overview of microwave signal capabilities in estimating the main land parameters of the hydrological cycle, e.g., soil moisture, vegetation water content, and snow water equivalent, on both local and global scales, with a particular focus on the applications of microwave indices.


Book
Novel Methods and Applications for Mineral Exploration
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ISBN: 3039289446 3039289438 Year: 2020 Publisher: MDPI - Multidisciplinary Digital Publishing Institute

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This special volume offers a snapshot of the latest developments in mineral exploration, in particular, geophysical, geochemical, and computational methods. It reflects the cutting-edge applications of geophysics and geochemistry, as well as novel technologies, such as in artificial intelligence and hyperspectral exploration, methods that have profoundly changed how exploration is conducted. This special volume is a representation of these cutting-edge and pioneering methods to consider and conduct exploration, and should serve both as a valuable compendium of the most innovative exploration methodologies available and as a foreshadowing of the form of future exploration. As such, this volume is of significant importance and would be useful to any exploration geologist and company


Book
Modelling and Calculation of Raw Material Industry
Authors: --- --- ---
Year: 2022 Publisher: Basel MDPI Books

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Abstract

The raw materials industry is widely considered to be too environmentally costly, and causing more losses than benefits. The responsible solving of the problems caused by this industry is not “exporting” its operations to less developed countries, but addressing all recognized hazards with dedicated technological developments. Such an approach is presented by the authors of this book. The contributions deal with the optimization of processes in the raw materials industry, obtaining energy from alternative fuels, researching the environmental aspects of industrial activities. This book determines some guidelines for the sustainable raw materials industry, describing methods of the optimized use of mined deposits and the recovery of materials, reductions in energy consumption and the recuperation of energy, minimizations in the emissions of pollutants, the perfection of quieter and safer processes, and the facilitation of modern materials-, water-, and energy-related techniques and technologies.

Keywords

Technology: general issues --- History of engineering & technology --- acid leaching --- battery recycling --- Li-ion batteries --- metal recovery --- raw material sustainable use --- sieving screen --- inertial vibrator --- dual-frequency --- spectrum --- FEM simulation --- biomass ash --- coal ash --- sintering --- mechanical test --- pressure drop test --- slagging --- fouling --- ion flotation --- used batteries --- ecological safety --- recovery --- Zn(II) --- Mn(II) --- belt conveyor --- prosumer --- downhill transport of overburden --- specific energy consumption --- recuperation --- energy recovery rate --- air quality monitoring --- SO2 --- VOC --- H2S --- PM10 --- PM2.5 --- PM1.0 --- outdoor air quality --- air flow aerodynamics --- street canyon --- digestate --- biogas plant --- hydrothermal carbonisation --- membrane processes --- water recovery --- thermal lag --- fossil fuels --- pyrolysis --- TG --- thermal analysis --- power --- powered roof support --- hydraulic leg --- bench testing --- dynamic load --- discrete event simulation --- quarry --- mine machine --- cost of production --- fire-side corrosion --- boiler tube wastage --- diagnostics --- industrial-scale boilers --- non-destructive inspection --- pipe inspection --- wall thickness measurement --- stone waste --- waste generation --- waste recycling --- industrial waste treatment --- sustainable manufacturing --- dimension natural stone processing --- GHG emissions --- stable isotopes --- waste management --- energy recovery --- unburned carbon --- fly ash --- activated carbon --- adsorption kinetics --- statistical regression --- sustainable mining --- heating and energy processes --- raw material sustainable-use fossil fuels --- energy conversion and storage --- air pollution --- emission reduction methods --- purification and removal techniques --- acid leaching --- battery recycling --- Li-ion batteries --- metal recovery --- raw material sustainable use --- sieving screen --- inertial vibrator --- dual-frequency --- spectrum --- FEM simulation --- biomass ash --- coal ash --- sintering --- mechanical test --- pressure drop test --- slagging --- fouling --- ion flotation --- used batteries --- ecological safety --- recovery --- Zn(II) --- Mn(II) --- belt conveyor --- prosumer --- downhill transport of overburden --- specific energy consumption --- recuperation --- energy recovery rate --- air quality monitoring --- SO2 --- VOC --- H2S --- PM10 --- PM2.5 --- PM1.0 --- outdoor air quality --- air flow aerodynamics --- street canyon --- digestate --- biogas plant --- hydrothermal carbonisation --- membrane processes --- water recovery --- thermal lag --- fossil fuels --- pyrolysis --- TG --- thermal analysis --- power --- powered roof support --- hydraulic leg --- bench testing --- dynamic load --- discrete event simulation --- quarry --- mine machine --- cost of production --- fire-side corrosion --- boiler tube wastage --- diagnostics --- industrial-scale boilers --- non-destructive inspection --- pipe inspection --- wall thickness measurement --- stone waste --- waste generation --- waste recycling --- industrial waste treatment --- sustainable manufacturing --- dimension natural stone processing --- GHG emissions --- stable isotopes --- waste management --- energy recovery --- unburned carbon --- fly ash --- activated carbon --- adsorption kinetics --- statistical regression --- sustainable mining --- heating and energy processes --- raw material sustainable-use fossil fuels --- energy conversion and storage --- air pollution --- emission reduction methods --- purification and removal techniques


Book
Modelling and Calculation of Raw Material Industry
Authors: --- --- ---
Year: 2022 Publisher: Basel MDPI Books

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Abstract

The raw materials industry is widely considered to be too environmentally costly, and causing more losses than benefits. The responsible solving of the problems caused by this industry is not “exporting” its operations to less developed countries, but addressing all recognized hazards with dedicated technological developments. Such an approach is presented by the authors of this book. The contributions deal with the optimization of processes in the raw materials industry, obtaining energy from alternative fuels, researching the environmental aspects of industrial activities. This book determines some guidelines for the sustainable raw materials industry, describing methods of the optimized use of mined deposits and the recovery of materials, reductions in energy consumption and the recuperation of energy, minimizations in the emissions of pollutants, the perfection of quieter and safer processes, and the facilitation of modern materials-, water-, and energy-related techniques and technologies.

Keywords

Technology: general issues --- History of engineering & technology --- acid leaching --- battery recycling --- Li-ion batteries --- metal recovery --- raw material sustainable use --- sieving screen --- inertial vibrator --- dual-frequency --- spectrum --- FEM simulation --- biomass ash --- coal ash --- sintering --- mechanical test --- pressure drop test --- slagging --- fouling --- ion flotation --- used batteries --- ecological safety --- recovery --- Zn(II) --- Mn(II) --- belt conveyor --- prosumer --- downhill transport of overburden --- specific energy consumption --- recuperation --- energy recovery rate --- air quality monitoring --- SO2 --- VOC --- H2S --- PM10 --- PM2.5 --- PM1.0 --- outdoor air quality --- air flow aerodynamics --- street canyon --- digestate --- biogas plant --- hydrothermal carbonisation --- membrane processes --- water recovery --- thermal lag --- fossil fuels --- pyrolysis --- TG --- thermal analysis --- power --- powered roof support --- hydraulic leg --- bench testing --- dynamic load --- discrete event simulation --- quarry --- mine machine --- cost of production --- fire-side corrosion --- boiler tube wastage --- diagnostics --- industrial-scale boilers --- non-destructive inspection --- pipe inspection --- wall thickness measurement --- stone waste --- waste generation --- waste recycling --- industrial waste treatment --- sustainable manufacturing --- dimension natural stone processing --- GHG emissions --- stable isotopes --- waste management --- energy recovery --- unburned carbon --- fly ash --- activated carbon --- adsorption kinetics --- statistical regression --- sustainable mining --- heating and energy processes --- raw material sustainable-use fossil fuels --- energy conversion and storage --- air pollution --- emission reduction methods --- purification and removal techniques


Book
Modelling and Calculation of Raw Material Industry
Authors: --- --- ---
Year: 2022 Publisher: Basel MDPI Books

Loading...
Export citation

Choose an application

Bookmark

Abstract

The raw materials industry is widely considered to be too environmentally costly, and causing more losses than benefits. The responsible solving of the problems caused by this industry is not “exporting” its operations to less developed countries, but addressing all recognized hazards with dedicated technological developments. Such an approach is presented by the authors of this book. The contributions deal with the optimization of processes in the raw materials industry, obtaining energy from alternative fuels, researching the environmental aspects of industrial activities. This book determines some guidelines for the sustainable raw materials industry, describing methods of the optimized use of mined deposits and the recovery of materials, reductions in energy consumption and the recuperation of energy, minimizations in the emissions of pollutants, the perfection of quieter and safer processes, and the facilitation of modern materials-, water-, and energy-related techniques and technologies.

Keywords

acid leaching --- battery recycling --- Li-ion batteries --- metal recovery --- raw material sustainable use --- sieving screen --- inertial vibrator --- dual-frequency --- spectrum --- FEM simulation --- biomass ash --- coal ash --- sintering --- mechanical test --- pressure drop test --- slagging --- fouling --- ion flotation --- used batteries --- ecological safety --- recovery --- Zn(II) --- Mn(II) --- belt conveyor --- prosumer --- downhill transport of overburden --- specific energy consumption --- recuperation --- energy recovery rate --- air quality monitoring --- SO2 --- VOC --- H2S --- PM10 --- PM2.5 --- PM1.0 --- outdoor air quality --- air flow aerodynamics --- street canyon --- digestate --- biogas plant --- hydrothermal carbonisation --- membrane processes --- water recovery --- thermal lag --- fossil fuels --- pyrolysis --- TG --- thermal analysis --- power --- powered roof support --- hydraulic leg --- bench testing --- dynamic load --- discrete event simulation --- quarry --- mine machine --- cost of production --- fire-side corrosion --- boiler tube wastage --- diagnostics --- industrial-scale boilers --- non-destructive inspection --- pipe inspection --- wall thickness measurement --- stone waste --- waste generation --- waste recycling --- industrial waste treatment --- sustainable manufacturing --- dimension natural stone processing --- GHG emissions --- stable isotopes --- waste management --- energy recovery --- unburned carbon --- fly ash --- activated carbon --- adsorption kinetics --- statistical regression --- sustainable mining --- heating and energy processes --- raw material sustainable-use fossil fuels --- energy conversion and storage --- air pollution --- emission reduction methods --- purification and removal techniques

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