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DESIGN AND IMPLEMENTATION OF RICH COMMUNICATION SERVICE SCENARIO REPLAYER AND PERFORMANCE EVALUATION OF APPLICATION SERVICEYellakonda, Amulya January 2015 (has links)
Rich Communication Services(RCS) program is a GSM Association (GSMA) initiative to create inter-operator communication services based on IP Multimedia Subsystem (IMS) . This initiative came up as the Global Telecom Operators ́response to the decline in their revenues and to help compete ’Over The Top’(OTT) service providers such as Viber, whatsapp, etc. RCS is an universal standard, making it inter-operable between mul- tiple service providers unlike OTT services with closed communities. RCS services use IMS as the underlying architecture with a RCS stack imple- mented into Android background service which offers high level API. For the purpose of testing RCS stack functionality which is usually affected by external dependencies like third party vendors, or ISP customizations in real telecommunication scenario, there is a persistent demand for scenario replay tools that can recreate the range of test conditions similar to those experienced in live deployments. There is also a need to evaluate the per- formance of service provided by application servers in the network in-order to predict the factors affecting the RCS service in general. In this work, we propose a tool to address the RCS scenario repro- duction in a test environment. The tool is implemented within an automated test environment with full control on interaction with the RCS stack, hence the ability to replay the scenario in a controlled fashion. To achieve the goal, the tool replays trace interactively with the RCS stack in a stateful manner , it ensures no improper packet generation which is critical feature for test environments where protocol semantics accuracy is fundamental. A detailed demonstration of how the tool can be deployed in test environ- ments is stated. A novel approach is used to validate the effectiveness of the replayed scenario, the sequence of events and states are compared to those from the recorded scenario using a call-back service to indicate the state. The replayed scenario showed strong relationship with the recorded RCS scenario. The paper also presents a performance evaluation of Application service by considering the request-reponse times of Network Registration procedure. The obtained results show that the average time taken for the Registration process is 555 milliseconds and in few instances there exists larger deviations from this average value showing the faulty behavior of the Server which is most crucial during the debugging process for the developers.
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Vliv bionomických vlastností motýlů na jejich habitatovou vazbu / The influence of butterfly life history traits on their resource usePAVLÍKOVÁ, Anežka January 2011 (has links)
I studied resource based habitat classification approach on different taxonomical and ecological group of butterflies and moths. I examine whether the RCS strategy of host plant and biotope influenced position of Lepidopteran species in ordination space.
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Investigation of RCS-enhancement devices inspired from reflectarrays and metamaterials / Etude sur les dispositifs d'amélioration de SER inspirés des reflectarrays et des métamatériauxSrour, Hussein 29 June 2018 (has links)
Aujourd'hui, la sécurité des cyclistes sur les routes est une préoccupation majeure. Les statistiques d'accidents montrent une augmentation de 12% des décès de cyclistes depuis 2010. L'objectif du projet national français CYCLOPE est d'améliorer la sécurité des cyclistes grâce à des dispositifs électroniques innovants. Dans le cadre de ce projet, ces travaux de thèse se concentrent sur l'amélioration de la détectabilité du cycliste par un véhicule équipé d'un radar anticollision. L'objectif est d'augmenter la réflexion du système vélo-cycliste pour que le niveau d'énergie rétrodiffusé soit suffisant pour provoquer une alarme. Pour atteindre cet objectif, deux approches sont étudiées dans cette thèse. La première approche vise à concevoir un réflecteur rétrodirectif inspiré des techniques utilisées pour les antennes réseaux réflecteurs. Ce réflecteur est destiné à être placé sur le vélo, comme un catadioptre. Le réflecteur utilise deux panneaux imprimés formant un dièdre aplati, dans un souci de compacité. L'utilisation des motifs imprimés permet de réaliser une loi de phase sur les panneaux et, par ce biais, de restaurer le comportement rétrodirectif mis à mal par l'applatissement. Une étude théorique du mode de fonctionnement de cette structure complexe est proposée, permettant de dégager ces potentialités mais également ces limitations. Finalement, une conception complète est menée pour un prototype à 24 GHz. Sa fabrication et sa caractérisation montrent sa capacité à améliorer la surface radar d'un cycliste. Dans la deuxième approche, le dispositif réfléchissant est destiné à équiper le cycliste lui-même, comme un gilet fluorescent. Le torse humain est modalisé sous la forme d'un cylindre multi-couches diélectriques avec pertes. En revêtant ce cylindre d'une couche de nature réfléchissante, il est possible d'améliorer sa rétrodiffusion. Le travail se concentre donc sur la recherche du profil de revêtement optimal. Pour ce faire, un modèle numérique basé sur la solution mathématique exacte du cylindre infini multi-couches est proposé. En utilisant ce modèle, on constate que la couche requise doit être réalisée par des matériaux à permittivité négative, synthétisables grâce à des métamatériaux. L 'étude est ensuite étendue au cas d'un cylindre fini, plus représentatif de la réalité. Des comparaisons sont menées avec une simulation électromagnétique rigoureuse / A cyclist safety nowadays on roads is a major concern. Accident statistics show an increase of 12 % of deaths of cyclists since 2010. In the French national project CYCLOPE, the aim is improve the safety of cyclists by developing innovative electronic devices. In the context of this project, the work in this thesis is concerned with enhancing the detectability of the cyclist by a vehicle equipped with an anti-collision radar. The objective hence is to enhance the reflection by the bicycle-cyclist system so that the backscattered energy level would be sufficient to cause an alarm. In order to attain this objective, two approaches are investigated in the thesis. In the first, the design of a retrodirective reflector inspired by reflectarrays is studied. This device is going to be attached to the bicycle to operate as a retroreflector. The reflector is formed of two panels attached and flattened till a certain degree. Equipping each of the two panels with printed phasing cells permits for the construction of a phase law that restores the retrodirective behavior of the corner dihedral after it being flattened. A theoretical study performed on the retrodirective mechanism permits to uncover the potentials as well as limits of such reflector. Finally, a prototype operating at 24 GHz is realized. Its performance validates its capacity to enhance the RCS of a bicycle-cyclist. In the second approach, the possibility of enhancing the backscattering by the cyclist body using a reflective jacket is discussed. The human torso can be modeled as a multi-layered lossy dielectric cylinder. By coating this cylinder with a layer of reflective nature, it is possible to enhance its backscattering. The work hence concentrates on finding the corresponding optimum coat profile. Therefore, a numerical model based on the exact mathematical solution of the multilayered infinite cylinder is proposed. Using this model, it is found that the required coat should be made of negative permittivity materials, synthesizable using metamaterials. The study then is concentrated on the case of a finite cylinder which more accurately represents the real case scenario. Finally, Electromagnetic full-wave simulations are performed to compare the infinite-based numerical model to the finite-based simulation results.
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A Study on the Scattering of Spheres and Cylinders Using the Conformal FDTD MethodChen, Guang-xian 24 July 2008 (has links)
FDTD can successfully simulate various kinds of phenomena of electromagnetic waves. Mainly, we use orthogonal Cartesian coordinate in general situations when we deal with the electromagnetic problems, but the curved geometry of the problem makes it difficult to obtain accurate results using conventional FDTD algorithm because of staircasing. To analyze curved geometry using Conformal FDTD can improve this shortcoming. The Conformal FDTD uses the regular FDTD equation for updating the magnetic field by using the electric field values along the distorted
contours, that are appropriately weighted with lengths of the contours. The Conformal FDTD technique is well suited for handling such curved geometries.
The moment method is used to convert the integral equation into a matrix equation.The major drawback of moment method (MoM) is the full matrix generation and huge computation time. The CFDTD directly approximates the differential operators in the Maxwell curl equation, and avoids using more mathematic formulae. This thesis uses Conformal FDTD to simulate RCS value of the cylinder and sphere and compare Conformal FDTD with Moment Method. We know that Conformal FDTD will save memory requirement and CPU time even more than Moment Method in layered structure.
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Development of an innovative system for pollution abatement in the new natural gas vehicles / Développement d'un système de dépollution innovant pour les nouveaux véhicules au gaz naturelNobre Mendes, Acacio Miguel 30 November 2015 (has links)
Ce travail traite de la réduction catalytique sélective des oxydes d’azote en utilisant du méthane comme agent réducteur sur catalyseurs bimétalliques Pd/Ce/zéolithes. Dans un premier temps, la méthode d’introduction du palladium, la teneur en palladium et cérium ainsi que l’ordre d’introduction des métaux ont été optimisés pour une formulation considérant une zéolithe MOR comme support catalytique. Puis, l'effet des différentes conditions opératoires ont été évalués. L’effet du support catalytique a été également étudié en comparant un catalyseur PdCe-BEA au catalyseur PdCe-MOR résultant de l’optimisation effectuée. Il a été montré que les deux catalyseurs possèdent différentes espèces métalliques conduisant ainsi à différentes performances catalytiques. Des Relations structure/réactivité ont été établies par différentes techniques de caractérisation et des résultats des tests catalytiques. Il a été mis en évidence un effet synergique résultant de la combinaison de ces deux catalyseurs dans le même pot catalytique (configurations lit mélangé et lit double). Un traitement thermique innovant appliqué au catalyseur PdCe-MOR, pendant sa préparation a été développé et optimisé. Dans certaines conditions, ce traitement conduit à l’amélioration de la performance catalytique, notamment, à une conversion de NOx à N2 et à une sélectivité de CH4 pour la réaction NOx RCS plus élevée. Enfin, des catalyseurs structurés ont été préparés par "washcoating" de PdCe-MOR sur des monolithes de cordiérite possédant des géométries différentes. Les paramètres de préparation ont été ainsi évalués par des techniques de caractérisations et par des tests en banc de gaz. / The selective catalytic reduction of nitrogen oxides, in lean-conditions, using methane as reductant (NOx CH4-SCR) over PdCe/zeolite-based catalysts was considered in this work. Preparation method for palladium introduction, palladium/cerium loadings and metal introduction order were optimised for a formulation considering MOR zeolite as the catalytic support. The effect of different test conditions, namely [CH4]/[NO] ratio and water presence in the reaction mixture was assessed. The effect of the zeolite support in the stabilisation of Pd/Ce species was also evaluated by preparing a similar PdCe-BEA catalyst to the optimised PdCe-MOR catalyst, considering the same metal loadings and preparation methods. Both catalysts exhibited different metal species and different catalytic performances. Structure-reactivity relationships were drawn from the comparison of several characterisation techniques and catalytic test results for both catalysts. A synergic effect resulting from the use of both catalysts in a single bed application (mixed-bed and dual-bed configuration) is reported. An innovative thermal treatment applied to PdCe-MOR catalyst during its preparation is reported. Under certain conditions, this treatment results in the enhancement of the catalytic performance, namely, in higher NOx conversion into N2 and CH4 selectivity towards NOx SCR. Structured catalysts were prepared by washcoating of PdCe-MOR onto cordierite monoliths with different geometry (cpsi). Preparation parameters were evaluated through characterisation techniques and the catalytic performance was assessed in a synthetic gas bench plant.
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Multiple electromagnetic scattering by spheres using the T-matrix formulation / Elektromagnetisk multipelspridning från sfärer med T-matrismetodenWallin, Marina January 2015 (has links)
Low observable technology is used in order to prevent detection, or to delay detection. Radar cross section is an important parameter in aircraft survivability since it measures how detectable an object is with radar. To find the radar cross section Maxwell's equations are solved numerically in the time-domain using a finite difference scheme. This numerical method called Finite Difference Time Domain is very suitable for structures including complex materials. However, this numerical method needs to be verified for large scale simulations, due to numerical dispersion errors. Therefore it is desirable to verify the accuracy of the numerical simulations. In this project, the analytical solution to the multiple scattering by two spheres is implemented using the T-matrix formulation. The analytical solution to the scattering problem is first validated with the analytical Mie-series solution then compared to the Finite Difference Time Domain implementation. The results imply that the difference between the numerical and analytical solution is larger for higher frequencies and larger computational volumes. / Smygteknik används för att förhindra detektering, eller för att fördröja detektion av ett flygplan. Radarmålarea är en viktig parameter för skyddsprestanda hos flygplan eftersom den mäter hur detekterbar ett föremål är med radar. För att hitta radarmålarean löses Maxwells ekvationer numeriskt i tidsdomänen med hjälp av ett finit differensschema. Den numeriska metoden som kallas Finita differensmetoden i tidsdomän, är mycket lämplig för strukturer med komplexa material. Den numeriska metoden behöver valideras för storskaliga simuleringar eftersom det förekommer felaktigheter på grund av den numeriska dispersionen. Därför är det önskvärt att kontrollera riktigheten av de numeriska simuleringarna. I detta projekt, är den analytiska lösningen till multipelspridning av två sfärer implementerad med hjälp av T-matrismetoden. Den analytiska lösningen på spridningsproblemet valideras först mot den analytiska Mie-serielösningen och sedan jämförs den med resultatet av simuleringarna med Finita differensmetoden i tidsdomän. Resultaten antyder att skillnaden mellan den numeriska och analytiska lösningen är större för högre frekvenser och större beräkningsvolymer.
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Analysis, Design and Measurements of Flat and Curved Circularly Symmetric High Impedance Surfaces for Curvilinear Antenna ApplicationsJanuary 2018 (has links)
abstract: In this dissertation a new wideband circular HIS is proposed. The circular periodicity made it possible to illuminate the surface with a cylindrical TEMz wave and; a novel technique is utilized to make it wideband. Two models are developed to analyze the
reflection characteristics of the proposed HIS.
The circularly symmetric high impedance surface is used as a ground plane for the design of a low-profile loop and spiral radiating elements. It is shown that a HIS with circular periodicity provides a wider operational bandwidth for curvilinear radiating elements such, such as loops and spirals, compared to canonical rectangular HISs.
It is also observed that, with the aid of a circular HIS ground plane the gain of a loop and a spiral increases compared to when a perfect magnetic conductor (PMC) or rectangular HIS is used as a ground plane. The circular HIS was fabricated and the loop and spiral elements were placed individually in close proximity to it.
Also, due to the growing demand for low-radar signature (RCS) antennas for advanced airborne vehicles, curved and flexible HIS ground planes, which meet both the aerodynamic and low RCS requirements, have recently become popular candidates within the antenna and microwave technology. This encouraged us, to propose a spherical HIS where a 2-D curvature is introduced to the previously designed flat HIS.
The major problem associated with spherical HIS is the impact of the curvature on its reflection properties. After characterization of the flat circular HIS, which is addressed in the first part of this dissertation, a spherical curvature is introduced to the flat circular HIS and its impact on the reflection properties was examined when it was illuminated with the same cylindrical TEMz wave. The same technique, as for the flat HIS ground plane, is utilized to make the spherical HIS wideband. A loop and spiral element were placed in the vicinity of the curved HIS and their performanceswere investigated. The HISs were also fabricated and measurements were conducted to verify the simulations. An excellent agreement was observed. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2018
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Odrazná plocha osobních automobilů / Radar cross section of passenger carsHanslík, Radovan January 2019 (has links)
This diploma thesis is aimed at radar cross section of passenger cars. Basic scattering parameters of simple targets are described. Some numeric methods used for computing radar cross section are discussed. CST Microwave Studio is used for simulation of passenger car with two different solvers. For the results there are plots of radar cross section of a car for 1 GHz, 24.125 GHz and 33 GHz. There is a plot of visualized hotspots.
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A Study on the Effects of Decoder Quantization of Digital Video Broadcasting - Return Channel over Satellite (DVB-RCS) Turbo CodesGorthy, Anantha Surya Raghu 29 December 2008 (has links)
No description available.
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Demonstration of Direct-on-filter FTIR to Estimate Silica, Kaolinite, and Calcite Mineral Fraction in Respirable Coal Mine Dust SamplesPokhrel, Nishan 09 September 2021 (has links)
Respirable coal mine dust (RCMD) has long been recognized as an occupational health hazard. In addition to coal, RCMD can contain minerals such as crystalline silica (i.e., most often present as quartz). There has been a resurgence of lung diseases among US coal miners since the late-1990s which has emphasized the need for better quartz monitoring, and better dust characterization in general. Quartz monitoring in coal mines has traditionally used infrared (IR) spectroscopy-based analytical methods such as the MSHA Method P7 that require significant sample preparation and must be performed in a centralized lab. There are generally thus days to weeks between dust sample collection and reporting of results, which can prevent the prompt mitigation efforts to better control dust and reduce exposures. Recently, a rapid analysis method for quartz has been developed by the US National Institute for Occupational Safety and Health (NIOSH) using direct-on-filter (DOF) Fourier Transform Infrared (FTIR) spectroscopy. The method has been demonstrated in a number of NIOSH-led studies using both laboratory and field samples, and the results show very good accuracy relative to the Method P7 reference. However, it has heretofore not been widely used by others or compared to results from other non-IR analytical methods. Moreover, while FTIR can allow the measurement of additional analytes, this has not yet been a focus of DOF FTIR for RCMD analysis. Analytes such as kaolinite and calcite could be of particular interest in the context of RCMD source apportionment.
In this thesis, the DOF FTIR method is used to estimate silica, kaolinite, and calcite mineral fraction in RCMD samples collected in 16 coal mines, and in the laboratory using dust source materials from those same mines. The results are compared to results from other dust characterization methods such as mass-based thermogravimetric analysis (TGA) and particle-based scanning electron microscopy with energy dispersive X-ray (SEM-EDX). Results indicate the usefulness of the DOF FTIR method, and comparison suggests the presence of significant non-carbonate minerals other than silica and kaolinite in the coal mine dust. The results also show that SEM-EDX frequently indicates more mineral content (primarily other aluminosilicates), than that is predicted by either FTIR or the TGA. Additionally, by focusing mainly on calcite (generally sourced from limestone-based rock dust used in coal mines to prevent coal dust explosion), the second part of this study explores basic source apportionment by analyzing mine samples and samples of major dust source materials (such as run-of-mine coal, rock strata, and rock dust products). Results show that calcite can serve as a suitable proxy for rock dust in coal mine dust, and the results are consistent with expectations surrounding the contribution of dust from different mine locations and sample sources. Additionally, the DOF FTIR also showed good agreement with the TGA and SEM-EDX. / Master of Science / Respirable dust generated in coal mines has long been recognized as an occupational health hazard. In addition to coal, coal mine dust can contain minerals such as crystalline silica, which is particularly hazardous. Since the mid-1990s, there has been an alarming and unexpected increase in lung diseases in coal miners. Respirable crystalline silica is assumed to be a likely causal factor for this resurgence of lung diseases, and this has emphasized the need for better respirable crystalline silica monitoring and to better understand coal mine dust composition. The standard method of measurement of silica (called the MSHA Method P7) generally takes days to weeks between dust sample collection and reporting of results, which can prevent the mine from taking prompt mitigative efforts to better control dust and reduce exposures. Recently, a rapid analysis method for silica has been developed by the US National Institute for Occupational Safety and Health (NIOSH) called the DOF FTIR (direct-on-filter Fourier Transform Infrared Spectroscopy). This method has been shown to have very good accuracy relative to the standard method (MSHA P7). However, it has heretofore not been widely used by others or compared to results from other analytical methods. Moreover, DOF FTIR can also be used to estimate other minerals of interest such as kaolinite and calcite, which can be important in the context of understanding coal mine dust sources.
In this thesis, the DOF FTIR method is used to estimate silica, kaolinite, and calcite mineral fraction in coal mine dust samples collected in 16 coal mines, and in the laboratory using dust source materials from those same mines. The results are compared to results from other dust analysis methods such as mass-based TGA (thermogravimetric analysis) and particle-based SEM-EDX (scanning electron microscopy with energy dispersive X-ray). Results indicate the usefulness of the DOF FTIR method, and comparison suggests the presence of significant non-carbonate minerals other than silica and kaolinite in the coal mine dust. The results also show that SEM-EDX frequently indicates more mineral content than that is predicted by either FTIR or the TGA. Additionally, by focusing mainly on calcite—which is generally sourced from limestone-based rock dust used in coal mines to prevent coal dust explosion—the second part of this study explores the sources of the dust by analysing samples collected in mines, and samples generated in lab from major dust source materials (such as the raw coal, rock strata, and rock dust products obtained from the mines). Results show that calcite can be representative of rock dust in coal mine dust, and the results are consistent with expectations surrounding the contribution of dust from different mine locations and sample sources. Additionally, the DOF FTIR also showed good agreement with the TGA and SEM-EDX.
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