The interest for various multimedia services accessed via the Internet has been growing immensely along with the bandwidth available. A similar development has emerged in the 3G mobile network. The focus of this master thesis is on the speech/audio part of a 3G multimedia application. The purpose has been to implement a traffic generating tool that can measure QoS (Quality of Service) in 3G networks. The application is compliant to the 3G standards, i.e. it uses AMR (Adaptive Multi Rate), SIP (Session Initiation Protocol) and RTP (Real Time Transport Protocol). AMR is a speech compression algorithm with the special feature that it can compress speech into several different bitrates. SIP signalling is used so that different applications can agree on how to communicate. RTP carries the speech frames over the network, in order to provide features that are necessary for media/multimedia applications. Issues like perception of audio and QoS related parameters is also discussed, from the perspective of users and developers.

Thesis (Ph. D.)--Indiana University of Pennsylvania. / Includes bibliographical references.

The aims of this thesis are to develop and validate a robust and efficient algorithm for the numerical solution of the equations of General Relativistic Hydrodynamics, to implement the algorithm in a computationally efficient manner, and to apply the resulting computer code to the problem of perturbed Bondi-Hoyle-Lyttleton accretion onto a Kerr black hole. The algorithm will also be designed to evolve the space-time metric, and standardised tests will be applied to this aspect of the algorithm. The algorithm will use up-to-date High-Resolution Shock-Capturing numerical schemes that have been developed for the stable and accurate solution of complex systems of equations. It will be built around the Adaptive Mesh Refinement and overlapping, curvilinear grid methodologies in order to extend these schemes to the efficient solution of two and three-dimensional problems. When implementing the algorithm, we will use previously written code libraries, where appropriate, to avoid excessive software development. We will validate the algorithm against standard test-cases for Special and General Relativistic Hydrodynamics, and for Einstein's equations for the evolution of the space-time metric. The methodologies we use will be tested to ensure that they lead to the stable and accurate numerical solution of these problems. Finally, the implemented algorithm will be applied to the problem of Bondi-Hoyle-Lyttleton flow onto a Kerr black hole in three dimensions. It will be validated against existing exact and numerical solutions of the problem, and then be used to perform an extensive parametric study of the problem, varying the spin of the black hole and the incident wind direction, and allowing for the perturbation of the fluid density upstream of the black hole. We will then analyze the results of the study, and present the complete set of results on a DVD accompanying this thesis.

En este trabajo se analiza el estado del arte de los sistemas de medida orientados a los clientes de baja tensión en Chilectra S.A. y las tendencias de sistemas de medida avanzada en el mundo. Se realiza una evaluación técnica - económica de tres escenarios: Un sistema de lectura remota con corte y reposición del servicio y dos sistemas con diferentes opciones de tarifas y servicios adicionales. Se determinan los beneficios y costos que determinan la rentabilidad del proyecto. En base a los resultados de la evaluación, se desarrolla una propuesta mínima funcional de las características del sistema. Se analizan los riesgos del proyecto, así como las especificaciones que hoy rigen. Se presentan alternativas de sistemas de medida avanzada presentes en el mercado y se plantean políticas a seguir de modo de incrementar la viabilidad del proyecto.

Dans le cadre de la fusion par confinement inertiel en attaque directe, l'utilisation de mousses en tant qu'ablateur permet de réduire les instabilités hydrodynamiques créées sur la cible par l'irradiation directe des faisceaux laser. Des études antérieures ont été réalisées en considérant cette mousse comme homogène. Or, étant composée de fibres de CH baignant dans du DT, elle présente un aspect hétérogène. Le but de cette thèse est d'étudier l'effet de cette hétérogénéité sur la vitesse du choc lors de l'irradiation laser de la cible. Une étude expérimentale sur tube à choc et des études numériques avec le code HERA nous ont permis de trouver que le choc se propage plus rapidement dans le milieu hétérogène que dans le milieu homogène de densité moyenne équivalente. Cette écart de vitesse dépend du taux de présence des fibres de CH, du rapport de densité entre les deux matériaux constituant la mousse, de leur coefficient adiabatique et de la géométrie de la mousse. Nous avons modélisé la mousse de diverses manières, en partant du plus simple au plus compliqué, afin de se rapprocher d'une configuration réaliste. La modification de la vitesse du choc étant dûe à la baroclinicité qui, lors de l'interaction du choc avec l'interface entre le CH et le DT, crée un dépôt de vorticité, responsable de l'accélération du choc. Par conséquent, une interface plane et perpendiculaire au front de choc maximise ce dépôt de vorticité et augmente les écarts de vitesse entre milieux hétérogènes et homogènes. Une corrélation entre l'énergie cinétique derrière le choc et la différence relative des vitesses de choc a été trouvée. Nous avons comparé nos résultats à deux modèles analytiques, mais le système n'étant pas fermé, nous ne pouvons pas, pour le moment, élaborer de modèle prédictif. / In the frame of the inertial confinement fusion in direct drive, the use of CH(DT) foams as ablator allows the reduction of hydrodynamic instabilities created on the target by the direct laser irradiation. In the past, studies have been carried out considering this foam to be a homogeneous medium. Yet, the foam is composed of CH and DT, so it presents heterogeneous features. We study the effects of the heterogeneity on the shock velocity when the laser irradiates the target. Thanks to experimental and numerical studies, we show that the shock propagates faster in the heterogeneous medium than in the homogeneous one with the same averaged density. This velocity gap depends on the presence rate of the CH fibers in the foam, the density ratio, the adiabatic coefficient and the foam geometry. We modelize the foam by different ways, more and more complex. The shock velocity modification is due to the baroclinicity which, during the interaction between the shock front and the interface, creates a vorticity deposition, responsible for the shock accceleration. Accordingly, a interface, which is plane and perpendicular to the front shock, maximises the vorticity deposition and increases the velocity gaps between heterogeneous and homogeneous media. We found a correlation between the kinetic energy behind the shock front and the velocities relative difference. We compared our results with two analytical models. However, the system is not closed, so we can't, for the moment, develop a predictiv model.

Automated guided vehicles (AGVs) are the key equipment of flexible production systems and an important means for realizing a modern logistics system that meets the demands of Industry 4.0. AGVs are used from the mid 50th to delegate monotonous work of delivering products from the human to the automated device. In the long run, the usage of AGVs brings huge benefits to the manufacturing companies. But the purchase and installation of these devices significantly increase operational costs. This fact halts small and medium-sized enterprises from adopting this technology on their shop floors. The idea of this thesis work is to design and create a device that can be retailed at a significantly lower price without compromising flexibility and functional properties, to be used by smaller businesses. For this mater are used more affordable parts that can bring the cost down of a final product. This work describes the process of developing a differential drive mobile platform under the control of the robotic operating system. The process includes the development of a virtual model; selection of required components and investigation of their compatibility; development of chassis, suspension, and gear system; development of a hardware interface to interact with hardware components; configuration of different algorithms of control, cartography, and navigation; evaluation of the device. The research method is used in this work is design and creation due to the necessity of creating a physical prototype. The budget specification for the project was set to 50000 SEK and the desired payload capacity was set to 100kg. The work has resulted in the creation of a prototype of the AGV. The cost of the project is 20595 SEK. The evaluation of a prototype resulted in a maximum towing force of 300N. The load capacity is limited by the mobile base is 400kg. Safety sensors are not used in this project as the device was meant to operate in a controlled environment. The work also gives an evaluation of the Gmapping algorithm in case of using the laser scanner (RPlidar A1) and two algorithms of navigation stack: TrajectoryPlannerROS and DWA planner. The final prototype is evaluated to support an autonomous movement within a controlled environment.

Moment methods derived from the kinetic theory of gases can be used for the prediction of continuum and non-equilibrium flows and offer numerical advantages over other methods, such as the Navier-Stokes model. Models developed in this fashion are described by first-order hyperbolic partial differential equations (PDEs) with stiff local relaxation source terms. The application of discontinuous-Galerkin (DG) methods for the solution of such models has many benefits. Of particular interest is the third-order accurate, coupled space-time discontinuous-Galerkin Hancock (DGH) method. This scheme is accurate, as well as highly efficient on large-scale distributed-memory computers. The current study outlines a general implementation of the DGH method used for the parallel solution of moment methods in one, two, and three dimensions on modern distributed clusters. An algorithm for adaptive mesh refinement (AMR) was developed alongside the implementation of the scheme, and is used to achieve even higher accuracy and efficiency. Many different first-order hyperbolic and hyperbolic-relaxation PDEs are solved to demonstrate the robustness of the scheme. First, a linear convection-relaxation equation is solved to verify the order of accuracy of the scheme in three dimensions. Next, some classical compressible Euler problems are solved in one, two, and three dimensions to demonstrate the scheme's ability to capture discontinuities and strong shocks, as well as the efficacy of the implemented AMR. A special case, Ringleb's flow, is also solved in two-dimensions to verify the order of accuracy of the scheme for non-linear PDEs on curved meshes. Following this, the shallow water equations are solved in two dimensions. Afterwards, the ten-moment (Gaussian) closure is applied to two-dimensional Stokes flow past a cylinder, showing the abilities of both the closure and scheme to accurately compute classical viscous solutions. Finally, the one-dimensional fourteen-moment closure is solved.

Antimicrobial resistance (AMR) is rapidly becoming a public health issue, as more and more infectious bacteria become resistant to our known antibiotics. Suggested reasons for the proliferation of these strains are misuse and overuse of antimicrobials, especially on an industrial level, in agriculture, livestock and aquaculture. These resistances are not unique for pathogenic bacteria but originates in nature where complicated systems of microbes interact with each other. Freshwater environments hold special interest as they provide drinking water, have unique biodiversity, and provide other ecosystem services. Soil environments have the most diverse microbial communities and are often the source of new discoveries in microbial functions and AMR interactions. Since the vast majority of microbes can’t be maintained in pure culture or replicated in the laboratory setting, metagenomic methods have proven to be vital for understanding the diversity and occurrence of AMR in the environment that would otherwise have remained unexplored and unaccounted for. By producing metagenomic pipelines that utilize parallel computing to handle vast amounts of data, a catalogue of AMR in 390 samples mainly from Scandinavia was created from two datasets. One of the datasets had been previously processed and published, while the other was managed from raw reads to metagenomic assembled bins. This revealed a difference in the distribution of resistance mechanisms that microbes utilize to achieve AMR based on lifestyle and that AMR can be found in most taxa as well as in any freshwater and soil environments.

Since their introduction in the 1950s, industrial Automated Guided Vehicles (AGV) have gone from automatic machinery limited by hardware to complex robots limited by software, called Autonomous Mobile Robots. Small and medium businesses need to be able to utilize cutting-edge technology. Therefore, this research focuses on deploying mapless AMRs on cheap open source AMRs in dynamic industrial environments. The study implements Dijkstra’s and A-STAR algorithms on a simulated Turtlebot3 model deployed in a Gazebo rendering of an industrial warehouse with moving objects added. The Turtlebot3 model traverses the environment where time and distance results are observed. The results shown in the research indicate that Dijkstra’s algorithm is barely affected by the change of the initial map state, while the A-STAR algorithm performed worse on average. Future work should focus on minimizing the sensors needed and continue testing with more algorithms, but early tests show promising results.

This study explores the potential benefits, limitations and drawbacks of usingLoRa with unmanned aerial vehicles (UAVs) and autonomous mobile robots (AMRs)together for warehouse management. Three research concerns are looked at in order toprovide a full analysis of the topic. First, the benefits, limitations and drawbacks of utilizingLoRa with UAVs and AMRs are discussed along with suggestions for how to get over thechallenges within warehouse management. Second, potential security risks with the usage ofLoRa in conjunction with UAVs and AMRs for warehouse management are recognized, andmitigation strategies are recommended. The study's last portion considers how warehousemanagement company Proton Finishing AB may utilize LoRa in combination with UAVs andAMRs to promote environmental sustainability.