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Dissertations / Theses on the topic 'TLM'
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1
Meliani, H. "Mesh generation in TLM." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381077.
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Witwit, Abdul-Mehdi Rahim Mohammed. "Meshing techniques for TLM diffusion problems." Thesis, University of Hull, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296281.
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Benkrid, A. "Real time TLM vocal tract modelling." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352958.
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Dantanarayana, Harshana G. "Application of TLM for optical microresonators." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12924/.
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Optical microresonators can form the basis of all-optical switching and control devices. The presented study is an exploration of the Transmission Line Modelling (TLM) method as a suitable candidate for designing optical microresonators. Chalcogenide glasses were identified as promising materials, with which to fabricate optical microresonators. The study presents the formulation of TLM in two dimensions to model nonmagnetic dielectric materials and a suitable computationally efficient yet flexible software design. Some methods for extracting spectral properties of resonators are compared and the modified difference Prony method was identified as a suitable tool to extract resonant frequencies and Q factors from a limited time signal. When applying TLM to microresonators of sub-wavelength dimensions it was understood that the method of discretisation plays an important role in accurately modelling microresonators. Two novel methods of discretisations -the same area method and the anti-aliasing method- were used to improve the accuracy significantly compared to existing mesh refinement techniques. Perfect matched layers (PMLs) were implemented to improve reflections from domain truncation using several methods. A Convolutional PML(CPML) was identified as the best, but it does not reach the efficiency of PMLs in the Finite Difference Time Domain (FDTD) method. Several frequency dependent refractive index models were proposed and implemented in TLM. A Tauc-Lorentz model was identified as the best fit to the experimental refractive index of three chalcogenide glasses, but a Sellmeier model with one term and a coefficient was efficient for TLM implementation. The main concern in the use of these models within TLM was shown to be the error arising due to mesh dispersion. Kerr nonlinear models were formulated and implemented in TLM and the models applied to the study of a waveguide junction. Compared to an equivalent implementation in a time domain beam propagation method, TLM models better represent the waveguide junction reflections.
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Kenny, Ciaran. "TLM and finite-difference : an algebraic comparison." Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338403.
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Chen, Dian. "Transmission line modelling (TLM) of physical systems." Thesis, University of Sheffield, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361632.
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Rebel, Jürgen N. "On the foundations of the transmission line matrix method." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959770089.
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Montón, i. Macián Màrius. "Checkpointing for virtual platforms and systemC-TLM-2.0." Doctoral thesis, Universitat Autònoma de Barcelona, 2010. http://hdl.handle.net/10803/32099.
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Un dels avantatges d'usar plataformes virtuals o prototipat virtual enlloc del maquinari real pel desenvolupament de programari encastat és la capacitat d'alguns simuladors de fer captures del seu estat.
Si el model del sistema complet és prou detallat, pot tardar uns quants minuts (inclús hores) per simular l'engegada d'un Sistema Operatiu. Si es pren una captura just després de que ha acabat d'engegar, cada cop que calgui corre el programari encastat, els dissenyadors poden simplement recuperar la captura i continuar-la. Recuperar una captura normalment porta pocs segons. Aquest guany es trasllada en una major productivitat, especialment quan es treballa amb sistemes encastat, amb programari complex sobre Sistemes Operatius com en els dispositius actuals.
En aquesta tesi es presenta en primer lloc el treball realitzat per afegir un llenguatge de descripció de sistemes anomenat SystemC a dues plataformes virtuals diferents. Aquesta tasca es realitzà per una eina comercial i desprès es traslladà a una plataforma de codi obert.
També es presenta una sèrie de modificacions al llenguatge SystemC per suportar la captura d'instantànies. Aquestes modificacions faran possible poder agafar l'estat de la simulació en SystemC i salvar-les al disc. Més tard, la simulació es pot recuperar en el mateix estat on es trobava, sense canvis en els seus components. Aquestes millores ajudaran al llenguatge SystemC a ser més àmpliament usat en el món de les Plataformes Virtuals.One advantage of using a virtual platform or virtual prototype over real hardware for embedded software development and testing is the ability of some simulators to take checkpoints of their state. If the entire system model is detailed enough, it might take several minutes (or even hours) to simulate booting the O.S. If a snapshot of the simulation is saved just after it has finished booting, each time it is necessary to run the embedded software, designers can simply restore the snapshot and go. Restarting a checkpoint typically takes a few seconds. This can translate into a major productivity gain, especially when working with embedded system with complex SW stacks and O.S. like modern embedded devices. In this dissertation we present in firstly our work on adding a description level language as SystemC to two Virtual Platforms. This work was done for a commercial Virtual Platform, and later translated to a open-sourced Platform. This thesis also presents a set of modifications to SystemC language to support checkpointing. These modifications will make it possible to take the state of a SystemC running simulation and save it to disk. Later, the same simulation can be restored to the same point it was before, without any change to the simulated modules. These changes would help SystemC to be suitable for use by Virtual Platforms as a description language.
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Yue, Yuan. "Simulation of reactive components by the TLM method." Thesis, University of Ottawa (Canada), 1993. http://hdl.handle.net/10393/10930.
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Several new models for the simulation of nonlinear components have been developed in this thesis. Firstly, the model of the stub terminated with a constant capacitance is established. Simulations of a lumped capacitance connected to a transmission line, as well as modelling of relative permittivity can be done by this approach. Secondly, the algorithm for the modelling of voltage-dependent capacitance is developed based on the model of the stub terminated with variable capacitance. Thirdly, a configuration for the simulation of series capacitance in the TLM mesh is derived. The scattering matrix and the transmission formula for the structure are developed. The structure can also be used to simulate series-connected varactor diodes. Finally, the simulation of a varactor diode is performed in the three-dimensional expanded-node scheme. In order to show the application of different models, some examples, simulation results and discussions are given in this thesis.
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Holley, Steven Keith. "Investigations in modelling magnetostriction by the TLM method." Thesis, University of Hull, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441587.
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Ahmadian, Mansour. "Transmission Line Matrix (TLM) modelling of medical ultrasound." Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/427.
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This thesis introduces TLM as a new method for modelling medical ultrasound wave propagation. Basic TLM theory is presented and how TLM is related to Huygens principle is discussed. Two dimensional TLM modelling is explained in detail and one dimensional and three dimensional TLM modelling are explained. Implementing TLM in single CPU computers and parallel computers is discussed and several algorithms are presented together with their advantages and disadvantages. Inverse TLM and modelling non linear wave propagation and different types of mesh are discussed. A new idea for modelling TLM as a digital filter is presented and removing the boundary effect based on digital filter modelling of TLM is discussed. Some modelling experiments such as : 1) Focusing mirror, 2) Circular mirror, 3) Array transducers, 4) Doppler effect, are presented and how to use TLM to model these experiments is explained. A new low sampling rate theory for TLM modelling is proposed and verified. This new theory makes the modelling of a much larger spaces practical on a given hardware platform.
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Paul, John. "Modelling of general electromagnetic material properties in TLM." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267589.
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Ogunsola, Adesegun A. "Railway interference management : TLM modelling in railway applications." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/20205.
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This thesis deals with the application of analytical and numerical tools to Electromagnetic Compatibility (EMC) management in railways. Analytical and numerical tools are applied to study the electromagnetic coupling from an alternating current (AC) electrified railway line, and to study the electrical properties of concrete structure - a widely used component within the railway infrastructure. An electrified railway system is a complex distributed system consisting of several sub-systems, with different voltage and current levels, co-located in a small area. An analytical method, based on transmissions line theory, is developed to investigate railway electromagnetic coupling. The method is used to study an electrified railway line in which the running rails and earth comprise the current retum path. The model is then modified to include the presence of booster transformers. The analytical model can be used to study the railway current distribution, earth potential and electromagnetic coupling - inductive and conductive coupling - to nearby metallic structures. The limiting factor of the analytical model is the increasing difficulty in resolving the analytical equation as the complexity of the railway model increases. A large scale railway numerical model is implemented in Transmission Line Matrix (TLM) and the electromagnetic fields propagated from the railway model is studied. As this work focuses on the direct application of TLM in railway EMC management, a commercially available TIM software package is used. The limitation of the numerical model relates to the increased computation resource and simulation time required as the complexity of the railway model increases. The second part of this thesis deals with the investigation of the electrical properties of concrete and the development of a dispersive material model that can be implemented in numerical simulators such as TIM. Concrete is widely used in the railway as structural components in the construction of signalling equipment room, operation control centres etc. It is equally used as sleepers in the railway to hold the rails in place or as concrete slabs on which the whole rail lines are installed. It is thus important to understand the contribution of concrete structures to the propagation of electromagnetic wave and its impact in railway applications. An analytical model, based on transmission line theory, is developed for the evaluation of shielding effectiveness of a concrete slab; the analytical model is extended to deal with reinforced concrete slab and conductive concrete. The usefulness and limitation of the model is discussed. A numerical model for concrete is developed for the evaluation of the effectiveness of concrete as a shield. Initially, concrete is modelled as a simple dielectric material, using the available dielectric material functionality within TLM. It is noted that the simple dielectric model is not adequate to characterise the behaviour of concrete over the frequency range of interest. Better agreement is obtained with concrete modelled as a dispersive material having material properties similar to that exhibited by materials obeying Debye equation. The limitations of the dispersive material model are equally discussed. The design of conductive concrete is discussed, these have application in the railway industry where old existing structures are to be converted to functional rooms to house sensitive electronic system. A layer of conductive concrete can be applied to the facade to enhance the global shielding of the structure.
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Elkalsh, Ahmed. "Coupled electro-thermal transmission line modelling (TLM) method." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/40661/.
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The theme of this thesis is concerned with the modelling of the multi-physics interactions that occur in lightning and arc discharge. The main contributions of this research are presented as combining different physical studies namely, electromagnetic (EM) propagation, thermal diffusion and non-linear materials using a numerical algorithm. The algorithm was developed based on the two dimensional (2D) numerical transmission line method (TLM). The algorithm was applied to several practical examples namely, to model the electro-thermal analysis and the temperature development in a plasmonic nano-heat sources for terahertz applications; to predict the shape and the location of an arc discharge channel caused by a lightning strike using electro-thermal analysis, and to model diverter strips for lightning protection on aeroplanes. Different electro-thermal coupling approaches, such as fully and partially coupled methods were used to investigate the efficiency and accuracy of the model. In the fully coupled method the thermal model was allowed to change the electrical properties of materials in the electromagnetic model. On the other hand partial coupling did not consider the temperature dependency of the electrical properties in the electromagnetics model. Both of the models used the dissipated power from the electromagnetic model as a source signal to evaluate the temperature profile in the thermal model. Also different coupling interval timesteps were investigated to minimize the computational power needed without affecting the model accuracy.
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Johns, David Philip. "A three-dimensional frequency-domain transmission-line modelling method." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318645.
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Ferro, Luca. "Vérification de propriétés logico-temporelles de spécifications SystemC TLM." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00633069.
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Au-delà de la formidable évolution en termes de complexité du circuit électronique en soi, son adoption et sa diffusion ont connu, au fil des dernières années, une explosion dans un très grand nombre de domaines distincts. Un système sur puce peut incorporer une combinaison de composants aux fonctionnalités très différentes. S'assurer du bon fonctionnement de chaque composant, et du système complet, est une tâche primordiale et épineuse. Dans ce contexte, l'Assertion-Based Verification (ABV) a considérablement gagné en popularité ces dernières années : il s'agit d'une démarche de vérification où des propriétés logico-temporelles, exprimées dans des langages tels que PSL ou SVA, spécifient le comportement attendu du design. Alors que la plupart des solutions d'ABV existantes se limitent au niveau transfert de registres (RTL), la contribution décrite dans cette thèse s'efforce de résoudre un certain nombre de limitations et vise ainsi une solution mature pour le niveau transactionnel (TLM) de SystemC. Une technique efficace de construction de moniteurs de surveillance à partir de propriétés PSL est proposée : cette technique, inspirée d'une approche originale existante pour le niveau RTL, est ici adaptée à SystemC TLM. Une méthode spécifique de surveillance des actions de communication à haut niveau d'abstraction est également détaillée. Les possibilités offertes par la technique présentée sont significativement étendues en proposant, pour les propriétés écrites en langage PSL, à la fois un support formel et une mise en oeuvre pratique pour des variables auxiliaires globales et locales, qui constituent un élément essentiel lors des spécifications à haut niveau d'abstraction. Tous ces concepts sont également implémentés dans un outil prototype. Afin d'illustrer l'intérêt de la solution proposée, diverses expérimentations sont effectuées avec des designs aux dimensions et complexités différentes. Les résultats obtenus permettent de souligner le fait que la méthode de vérification dynamique suggérée reste applicable pour des designs de taille réaliste.
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Chughtai, Farooq Khalid. "Accurate Performance Exploration of System-on-Chip using TLM." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-92231.
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Increased complexity of system-on-chips (SoC) makes performance exploration with register transfer level (RTL) models to be both time consuming and to appear too late in the design cycle. Instead of RTL, transaction level models (TLM) have emerged as a dominant candidate for modeling of these complex SoCs. Transaction level models are abstracting implementation details and are therefore less complex to implement and execute much faster than RTL. However, an open issue is to define and measure how accurate TLM models are as compared to RTL. In this thesis, accuracy of a TLM model is defined and quantified by introducing metrics that are used to compare RTL and TLM models. The metrics introduced are transaction time, start time, relative throughput and transaction reordering. From the metrics, an error between RTL and TLM is calculated and presented. The thesis discusses how to generate proper stimuli for models, collect the metric, and how to calculate and represent the error to the designer. The proposed methodology for accuracy measurement is using TLM2 definitions and may therefore be applied to any TLM model. This methodology is applied to experiment a multi-port memory that is modeled as an approximately timed TLM. Defined metrics are collected from the same scenarios applied to both RTL and TLM models. Accuracy measurements at system and sub-system level can be integrated with the verification environment to systematically develop and refine accurate TLM models for performance exploration
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Jaques, Stuart Roland. "A TLM analysis of an all-optical switching device." Thesis, University of Hull, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363266.
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Orme, E. A. "TLM applied to the modelling of underwater acoustic scattering." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371287.
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Leonard, Gordon. "Acoustic modelling of bat pinnae utilising the TLM method." Thesis, Loughborough University, 2006. https://dspace.lboro.ac.uk/2134/20204.
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This thesis describes the numerical modelling of bioacoustic structures, the focus being the outer ear or pinnae of the Rufous Horseshoe bat (Rhinolophus rouxii). There have been several novel developments derived from this work including: • A method of calculating directionality based on the sphere with a distribution of measuring points such that each lies in an equal area segment. • Performance estimation of the pinna by considering the directionality of an equivalent radiating aperture. • A simple synthetic geometry that appears to give similar performance to a bat pinna. The outcome of applying the methods have yielded results that agree with measurements, indeed, this work is the first time TLM has been applied to a structure of this kind. It paves the way towards a greater understanding of bioacoustics and ultimately towards generating synthetic structures that can perform as well as those found in the natural world.
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Heleno, Evandro Fernandes. "Avaliação de câmaras reverberantes através do método numérico TLM." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-01122006-121507/.
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O presente trabalho tem por objetivo avaliar o comportamento dos campos eletromagnéticos no interior de câmaras reverberantes de modos misturados através do método numérico TLM (Transmission Line Matrix). Inicialmente, apresenta-se uma descrição dos diversos tipos de câmaras aplicáveis na avaliação de desempenho de compatibilidade eletromagnética de equipamentos e sistemas elétricos, destacando-se suas principais características físicas e geométricas, com ênfase nas câmaras reverberantes. Os aspectos teóricos relacionados à descrição do método TLM são detalhados e sua aplicação na avaliação do ambiente eletromagnético das câmaras é então abordada. Diversos resultados são apresentados, considerando-se configurações pré-definidas de câmaras reverberantes, ressaltando-se a definição e cálculo de índices de mérito, bem como os principais aspectos relacionados à representação e definição de critérios adotados nas simulações destas.The aim of this report is the evaluation of the behavior of electromagnetic fields inside reverberation chambers by means of Transmission Line Modeling (TLM). Initially, it is presented a description of several kinds of chambers applicable for electromagnetic compatibility tests followed by a more detailed description regarding reverberation chambers. Theoretical aspects of TLM method and its application for electromagnetic fields solution are covered. Some results are presented, considering pre-defined reverberation chambers configurations, highlighting some merit indicators and the main aspects adopted on its simulation.
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Austin, John Dawson. "General curvilinear orthogonal meshes for use in TLM diffusion applications." Thesis, University of Hull, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335178.
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Forest, Michel. "Synthesis of microwave structures by inversion of the TLM process." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7670.
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This thesis presents a novel numerical synthesis technique based on the time reversal property of the Transmission-Line Matrix method (TLM). It allows the designer to generate the geometry of a passive circuit from its desired frequency response using alternate forward and backward time-domain analyses. This approach opens new doors in microwave synthesis and offers an advantageous alternative to the traditional synthesis techniques using frequency domain analysis. To demonstrate and validate the procedure, an inductive obstacle inside a waveguide will be synthesized.
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Chen, Zhizhang. "The transmission line matrix (TLM) method and its boundary treatments." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/10888.
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The Transmission Line Matrix (TLM) numerical algorithm, based on the discrete Huygens' principle, has been extensively used to solve electromagnetic structure problems. The major advantage of this method is its simplicity and flexibility as the vectorial Maxwell's Equations are transformed into a simple numerical model of digital signal processing system. In this thesis, new and efficient numerical modeling concepts and procedures have been developed for the analysis of electromagnetic structures with the TLM method: (1) With the introduction of the equivalent field quantities defined between nodes, the TLM Method has been shown to be exactly equivalent to a finite-difference timedomain (FD-TD) formulation. Therefore, the numerical foundation of the TLM approach has been fully demonstrated and the basis for mathematically understanding the TLM method has been provided. As a result, the conventional TLM boundary conditions has been verified theoretically, and hence a systematic way for constructing the TLM boundary conditions has been developed. In addition, a new boundary description for the TLM method has been proposed, which renders TLM method more flexibility in its boundary treatments. (2) Based on the equivalence between the TLM method and the FD-TD method, an absorbing and a connecting boundary formulations have been developed for TLM simulations. With these formulations, the TLM method can be applied for solving more realistic scattering and radiation problems with open structures. The computation examples given in this thesis are with the structures of waveguides, two-dimensional and three-dimensional obstacles illuminated by plane waves. The numerical results show good agreement with those obtained with the Method of Moment, and thus validate the boundary conditions developed. (3) By using the discrete Fourier Transform, a new algorithm has been developed for interfacing the TLM method with the frequency-domain solutions. The technique employ the prior knowledge of frequency-domain solutions at boundaries and combine them with TLM simulations, leading to considerable decrease in memory and CPU time. It also allows the TLM method to be used with highly conductive materials for solving shielding problems. The good results were obtained with significant reduction of the computation expenditure.
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So, Poman. "Modelling of complex electromagnetic structures with TLM, theory and practice." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21949.pdf.
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Vongurai, Rawin. "Development of digital filtering techniques in three-dimensional TLM models." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13651/.
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Digital filtering (DF) techniques are receiving significant interest, because they can represent fine features such as vias, thin-panels and thin-wires in full-field solutions of electromagnetic problems with significant savings in computational costs. However, a limitation of this technique is that DF can only represent a fine feature as a plane or as an internal boundary. In other words, an internal boundary can represent the electromagnetic properties of a fine feature in one dimension or two directions. The DF technique is usually involved with time domain solvers such as the Finite-difference time-domain (FDTD) and the Transmission Line Modeling (TLM) methods. Both of them are commonly used to investigate the electromagnetic fields in the problem spaces. Here the TLM method is selected for demonstrating the DF technique. This thesis presents the formulation of TLM in three-dimensions in order to investigate the limitations of the DF technique and the solutions. As a result, new techniques have been developed. These techniques can be applied to the three dimensional TLM method in order to represent the fine features in three-dimensions appropriately. The developed techniques were demonstrated using some examples of three-dimensional embedded objects, such as conducting volumes and dielectrics. Their accuracy and efficiency are compared with the standard TLM method in the time and frequency-domain. The results show good agreement between these techniques and the standard TLM method.
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Janyani, Vijay. "Modelling of dispersive and nonlinear materials for optoelectronics using TLM." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417228.
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Ng, Ming Wah. "TLM modelling of microstrip patch antenna on magnetized ferrite substrate." Thesis, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405515.
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Delbergue, Guillaume. "Advances in SystemC/TLM virtual platforms : configuration, communication and parallelism." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0916/document.
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Le marché de l’Internet des Objets (IdO) est en pleine progression. Il va continuer à croître et à se développer à un rythme soutenu dans les prochaines années. Les objets connectés sont constitués de composants électroniques dédiés, de processeurs et de codes logiciels. La conception de tels systèmes constitue aujourd’hui un challenge au niveau industriel. Ce challenge est renforcé par la concurrence du marché et le délai de commercialisation qui impactent directement sur le développement d’un système. Le processus de conception actuel consiste en l’élaboration d’un cahier des charges. Dans un premier temps, l’équipe en charge du développement matériel commence à développer le produit. Ensuite, la partie applicative peut être mise au point par les développeurs logiciels. Une fois le premier prototype matériel disponible, l’équipe logicielle peut alors intégrer sa partie et tenter de la valider fonctionnellement. Cette étape peut mettre en lumière des défauts dans le logiciel mais aussi lors de la conception matérielle. Malheureusement,la découverte ce type d’erreurs intervient beaucoup trop tard dans le processus de conception retardant la commercialisation du système. Afin de sécuriser au plus tôt les développements matériel et logiciel, des méthodologies basées sur le standard SystemC/Transaction Level Modeling (TLM) ont été proposées. Elles permettent de modéliser et de simuler du matériel. Durant les phases amont de conception d’un système, elles permettent de mettre en commun une version virtuelle du (futur) système entre les équipes logicielle et matérielle. Cette version virtuelle est plus couramment appelée plateforme virtuelle. Elle permet de tester et de valider le plus tôt possible lors du cycle de conception, de réduire le coût matériel en limitant la fabrication de prototypes, mais aussi de gagner du temps et donc de l’argent en diminuant les risques. Or, les objets intègrent de plus en plus de fonctionnalités aux niveaux matériel et logiciel. Les besoins ayant évolué, le standard de simulation SystemC/TLM ne répond plus à l’heure actuelle à toutes les attentes. Ces attentes concernent plus particulièrement les aspects liés à la simulation de systèmes composés de nombreuses fonctionnalités, de protocoles de communication disparates mais aussi de modèles complexes et consommateur de temps pendant la simulation. Des activités de recherche ont déjà été menées sur ces sujets. Cependant, elles ont pour la plupart abouti à des solutions qui ne sont pas interopérables. Les solutions existantes ne permettent donc pas de bénéficier de la réutilisation des modèles de la littérature. Afin de répondre à ces problèmes,une solution permettant la configuration de modèles SystemC/TLM a été recherchée. Cette dernière fait désormais partie du standard Configuration, Control and Inspection (CCI). Dans un second temps, la modélisation de protocoles de communication à un haut niveau d’abstraction(TLM Loosely Timed (LT) et Approximately Timed (AT)) a été étudiée, et plus précisément des protocoles de type non bus. Une évolution du standard actuel permettant d’améliorer le support,l’interopérabilité, la réutilisation a été proposée dans le cadre de la thèse. Ensuite, une évolution du standard SystemC et plus précisément du comportement du noyau de simulation a été étudiée pour supporter l’attente d’événements asynchrones. Ce type d’événement ouvre la voie à la parallélisation et la distribution de modèles sur différents threads / machines. Enfin, une solution permettant l’intégration de modèles de Central Processing Units (CPU) intégrés dans QuickEMUlator (QEMU), un émulateur / virtualisateur de système, a été étudiée. Finalement, toutes ces contributions ont été associées à travers la modélisation d’un ensemble d’objets connectés à une passerelleThe market for Internet Of Things (IOT) is on the rise. It is predicted to continue to grow at a sustained pace in the coming years. Connected objects are composed of dedicated electronic components, processors and software. The design of such systems is today a challenge from an industrial point of view. This challenge is reinforced by market competition and time tomarket that directly impact the success of a system. In a current design process involvesthe development of a specification. Initially, the team in charge of hardware development beginsto design the system. Second, the application part can be done by software developers. Oncethe first hardware prototype is available, the software team can then integrate their part and try tovalidate the functionality. This step may reveal defects in the software but also in the hardware architecture. Unfortunately, the discovery of these errors occurs far too late in the design process,could impacts the marketing of the system and potentially its success. In order to ensure that the hardware and software designs will work together as early as possible, methodologies based onthe SystemC / Transaction Level Modeling (TLM) standard have been widely adopted. They involvethe modelling and simulation of the proposed hardware architectures. During the initial phasesof a product’s design, they enable the software and hardware team to share a virtual version ofthe (future) system. This virtual version is more commonly referred to as a virtual platform. It facilitates early software development, test and validation; reduces material cost by limiting the number of prototypes; saves time and money by reducing risks. However, connected objects are increasingly incorporating hardware and software features. As the requirements have evolved, theSystemC / TLM simulation standard no longer meets all expectations. It includes aspects related to the simulation of systems composed of many functionality, disparate communication protocolsbut also complex and time consuming models during the simulation. Some works have already been carried out on these subjects. However, as the number of components increases, all formsof interoperability of models and tools become increasingly difficult to handle. Moreover, mostof the research has resulted in solutions that are not inter-operable and can not reuse existingmodels. To solve these problems, this thesis proposes a solution for configuring SystemC / TLMmodels. It is now part of the standard Configuration, Control and Inspection (CCI). In a secondstep, the modeling of high-level abstraction communication protocols (TLM Loosely Timed (LT)and Approximately Timed (AT)) has been studied, as it relates to non-bus protocols. An evolution of the standard to improve support, interoperability and reuse is also proposed. In a third step,a change of the SystemC standard and more precisely of the behavior of the simulation kernelhas been studied to support asynchronous events. These open the way to parallelization and distribution of models on different threads / machines. In a fourth step, a solution to integrate Central Processing Units (CPU) models integrated in Quick EMUlator (QEMU), a system emulator/ virtualizer, has been studied. Finally, all these contributions have been applied in the modeling ofa set of objects connected to a gateway
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Tickes, Barry, and Mike Ottman. "Wheat and Barley Variety Demonstration - 1986 - TLM Farms - Yuma, AZ." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200548.
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On farm variety demonstrations are conducted by the Cooperative Extension Service to demonstrate the commercial potential of new and established varieties of wheat and barley when grown under various environmental and management conditions. As part of an ongoing variety demonstration program conducted in Yuma County, Arizona for the past 20 years, this study was conducted at TLM Farms on the south Yuma Mesa on extremely coarse-textured sandy soils under sprinkler irrigation. Five hard red spring wheat, six durum and four barley varieties were evaluated under TLM Farms management using 13 ft x 275 ft randomized plots with four replications. Statistically significant yield differences were measured that suggest, when compared to previous and other studies, that variety performance on coarse textured, sprinkler-irrigated soils is different than on finer textured flood-irrigated soils.
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Burton, James D. "Parallel simulation of hydraulic systems using transmission-line modelling (TLM)." Thesis, University of Bath, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387215.
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Cabral, Sérgio Henrique Lopes. "Análise de transitórios elétricos em transformadores através do método TLM." Florianópolis, SC, 2003. http://repositorio.ufsc.br/xmlui/handle/123456789/85438.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.Made available in DSpace on 2012-10-20T18:42:21Z (GMT). No. of bitstreams: 1 194166.pdf: 1134039 bytes, checksum: d3ac74670e71af4a3122262eb120e8e6 (MD5)
Este trabalho apresenta a aplicação eficiente do método numérico TLM- Transmission Line Method na solução dos principais problemas relacionados a transitórios elétricos em transformadores elétricos. Dadas a simplicidade e a eficiência desse método, torna-se possível o desenvolvimento de programas computacionais para a análise de diversos projetos de transformadores frente às solicitações transitórias elétricas, segundo as particularidades de cada fabricante, através de planilhas eletrônicas. Inicialmente, se define e justifica quais vêm a ser os três principais casos de transitórios elétricos relacionados a transformadores e a importância da análise desses casos, no contexto regional. Em seguida, esses três casos são analisados de forma teórica, baseando-se no que há de mais atual em cada um deles. Desta forma, se demonstra a necessidade do uso de ferramentas computacionais eficientes para a análise dos casos. Então, o método TLM é apresentado, através de exemplos relacionados aos três principais casos e em seguida cada um desses três casos é simulado, com a base no método. Dada a coerência obtida, a apresentação culmina com a validação experimental dos três casos, permitindo vislumbrar a aplicação do método em diversas outras situações particulares , de interesse de fabricantes de transformadores. A forma simples como os programas computacionais podem ser desenvolvidos é enfatizada.
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Hayat, Zeeshan. "Evaluating Parallelization Potential for a SystemC/TLM-based Virtual Platform." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254883.
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System on chip (SoC) solutions, with integrated hardware and embedded software, are increasing in size and complexity. To cope with the market demand for complex SoC, the abstraction level used during development is raised to allow co-development of software (SW) and hardware (HW). Functional and bit-accurate simulators, referred to as Virtual Platforms, play a vital role in co-development of HW and SW. A virtual platform supports early development, testing, and verification of the embedded SW. However, as the complexity of SoC is increasing so does the complexity of virtual platforms, which is a major bottleneck in the performance of the virtual platforms.SystemC is an industry standard supporting development of hardware models. SystemC uses co-routine semantics, also known as co-operative multitasking, for the control of simulation. A single process is active at any time. This means that the potential for parallelism, by executing a SystemC simulation on multiple cores in a modern multi-core processor, is not utilized.This thesis work proposes a parallelization algorithm for SystemC simulations, where one SystemC thread controls a set of parallel host threads. A proof of concept trace-driven simulator is developed to verify the results from the proposed algorithm. Also, an optimized algorithm is proposed which improves the simulation speed. Furthermore, the behavior of the simulator is analyzed by looking into traces, from the Linux kernel and user application level traces, with the help of an open source tracing framework known as LTTng.The trace-driven simulator is used for evaluation of the parallelization potential for SVP, a virtual platform used at Ericsson. The evaluation makes it possible to determine, for the ideal case when the threads execute independently, the maximum possible speedup for a given test case. Using test cases from production usage, an evaluation of the possible performance improvements for SVP can be done.System på chip (SoC) -lösningar, med integrerad hårdvara och inbyggd programvara, ökar i storlek och komplexitet. För att klara av marknadens efterfrågan på komplexa SoC höjs den abstraktionsnivå som används under utveckling, för att möjliggöra samutveckling av programvara (SW) och hårdvara (HW). Funktionella och bitexakta simulatorer, benämnda virtuella plattformar, spelar en viktig roll vid samutveckling av HW och SW. En virtuell plattform stöder tidig utveckling, samt testning och verifiering av den inbäddade programvaran. Eftersom komplexiteten i SoC ökar så ökar även komplexiteten hos virtuella plattformar, vilket begränsar prestandan för de virtuella plattformarna.SystemC är en industristandard som stöder utveckling av hårdvarumodeller. SystemC använder händelse-styrd simulering. I ett give tidsögonblick är endast en process aktiv. Detta innebär att potentialen för parallelism, genom att utföra en SystemC-simulering på flera kärnor i en modern multi-core-processor, inte utnyttjas.Detta examensarbete presenterar en parallelliseringsalgoritm för SystemC-simuleringar, där en SystemC-tråd styr en uppsättning parallella värdtrådar. En data-driven simulator, som använder sig av inspelade data från en virtuell plattform, utvecklad för att verifiera resultaten från den föreslagna algoritmen. Dessutom föreslås en optimerad algoritm som förbättrar simuleringshastigheten. Dessutom analyseras beteendet hos simulatorn genom att presentera process-akiviteter, från Linuxkärnan samt från applikationen, met de hulp van een open source tracing framework bekend als LTTng.Den data-drivna simulatorn används för utvärdering av parallelliseringspotentialen för SVP, en virtuell plattform som används på Ericsson. Utvärderingen gör det möjligt att, för det ideala fallet när trådarna exekverar helt parallellt bestämma maximal möjlig hastighet för ett givet testfall. Genom att använda testfall från produktionskod kan en utvärdering av möjliga prestandaförbättringar för SVP utföras.
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Revol, Sébastien. "Profil UML pour TLM : contribution à la formalisation et à l'automatisation du flot de conception et vérification des systèmes-sur-puce." Grenoble INPG, 2008. http://www.theses.fr/2008INPG0065.
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Les travaux présentés dans cette thèse portent sur l'étude du langage UMl pour la conception des systèmes sur puce. La contribution pcindpale est la définition et l'exploitation d'un profil rapprochant les flots de conception fondés sur l'Unified Modeling Language et les standards traditionnellement employés dans l'indusbie électronique au niveau système, tels que Systemc-TLM et IP-XACT. AInsi, ensappuyant sur les techniques de l'Ingénierie Dirigée par les Modèles, des passerelles ont été établies afin d'assurer des opérations d1mport-export entre des desaiptions de composants matériels en IP-XACT et UMl, ainsi que la génération depuis ce langage d'une grande partie du code SystemC-TlM des composants. Une évaluation sur un cas d'étude Industriel démontre les intérêts de cette approche, en termes de condslon du langage, de Qualité du code généré, et au final de gain de temps pour la réalisation et l'intégration de modèles TlM. Pour ce cas, le gain a été évalué à un facteur 3 à 4The work presente
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Nepomuceno, Fraga Fabio. "Contribuições para o desenvolvimento de uma metodologia para avaliação de sistemas de aterramento em alta freqüência empregando TLM tridimensional." Universidade Federal de Pernambuco, 2008. https://repositorio.ufpe.br/handle/123456789/5233.
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Previous issue date: 2008Este trabalho apresenta um estudo do comportamento de sistemas de aterramento submetidos a fenômenos transitórios. Busca apresentar contribuições para o desenvolvimento de uma metodologia capaz de avaliar grandes sistemas de aterramento empregando o método TLM (Transmission-Line Modeling) tridimensional para simulação. Com o objetivo de determinar a influência de parâmetros geométricos no comportamento de sistemas de aterramento várias configurações são simuladas. São apresentados os conceitos de Área Sensível e Zona de Influência que constituem uma importante contribuição para análise de sistemas de aterramento em alta freqüência. Um Fluxograma de ações para avaliação destes sistemas é apresentado. É realizado um estudo de caso aplicando a metodologia proposta em uma malha de terra de uma subestação de 230 kV da Chesf onde soluções mitigadoras para os problemas de sobretensões são estudadas e propostas. Entre as soluções estudadas a escolha do ponto de conexão mais adequado para um elemento à malha de terra constitui um importante fator a ser observado
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Tardioli, Giampaolo. "Modeling of fine geometric details and singular field regions in TLM." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0001/NQ34286.pdf.
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Raynes, Deborah Louise. "The analysis and design of TLM mesh configurations for modelling electromagnetics." Thesis, University of Hull, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310310.
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Stubbs, David Michael. "Modelling distributed amplifier structures using the transmission line matrix (TLM) method." Thesis, University of Hull, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395515.
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Trenkić, Vladica. "The development and characterization of advanced nodes for the TLM method." Thesis, University of Nottingham, 1995. http://eprints.nottingham.ac.uk/12113/.
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Propagation of electromagnetic waves in three-dimensional (3D) space is studied using the Transmission-Line Modelling (TLM) method. The theoretical foundation, generalization and more advanced versions of the symmetrical condensed node (SCN), a basic structure for 3D TLM modelling, are presented. A unified approach to the derivation of TLM schemes capable of modelling nonuniform anisotropic materials on an arbitrarily graded mesh is introduced. The parameters and the scattering properties for a general symmetrical condensed node (GSCN) constructed from link lines with arbitrary characteristic impedances and up to six stubs are described. For the first time in 3D TLM modelling it is shown that stubs can be removed completely from the SCN, whilst still allowing general inhomogeneous problems to be modelled. This development, described as the symmetrical super-condensed node (SSCN), contributes significant reductions in memory storage and computer run-time in TLM simulations. In order to assess accuracy and numerical dispersion in the various TLM schemes based on the GSCN, dispersion relations are studied. A general approach for the analytical expansion of the general dispersion relation is introduced, enabling the derivation of dispersion relations in algebraic form for all currently available nodes. Based on the results obtained from the dispersion analysis, work aimed at constructing an optimal node is described. A class of adaptable symmetrical condensed nodes (ASCN) is derived, with superior propagation characteristics compared to other known TLM nodes.
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Ungureanu, Alina. "Synthèse de sources rayonnantes large bande, par la méthode TLM inverse." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00767009.
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Cette thèse porte sur la synthèse des sources électromagnétiques (EM) rayonnantes, par la méthode TLM (Transmission Line Matrix) inverse. Les applications large-bande sont particulièrement visées. L'objectif est d'utiliser la théorie du retournement temporel des ondes EM, afin d'implémenter et développer une nouvelle méthode de synthèse des sources rayonnantes, à partir d'un diagramme de rayonnement connu. La retro-propagation des ondes est réalisée numériquement, par la méthode TLM inverse, en trois dimensions (3D), à nœuds symétriques condensés (SCN). L'algorithme proposé est utilisé pour retrouver des sources EM primaires, ponctuelles et réparties, émettant des signaux à large-bande [26GHz - 34GHz] et placées dans l'espace libre (sans pertes, homogène et non-dispersif). Les bases, le potentiel et les limites de cette approche inverse sont étudiés. Une étape supplémentaire est ajoutée afin d'améliorer la résolution spatiale de la reconstruction des sources ponctuelles et réparties. Une résolution inferieure à la demi-longueur d'onde de l'excitation est ainsi obtenue. La reconstruction des sources secondaires 1D et 2D, induites sur les surface métalliques des antennes est ensuite étudiée. Ces études ont abouti au développement d'un nouvel outil de simulation, basé sur une méthode hybride TLM-analytique. La synthèse des sources induites sur la surface d'une antenne-monopôle est ainsi réalisée, à partir du CL mesuré. L'orientation et la position des sources sont trouvées. Les avantages et les limitations de la technique sont enfin discutés.
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Tosi, Hervé. "Modélisation d'antennes reconfigurables à diodes PIN et Varicap par la TLM." Nice, 2003. http://www.theses.fr/2003NICE4051.
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Les antennes actives sont des structures rayonnantes compactes intégrant des éléments actifs. Les composants intégrés permettent de réaliser des fonctions d’oscillation, d’amplification et de communication directement sur l’antenne, évitant ainsi les pertes ohmiques et l’addition de bruits sur les signaux à traiter ? La multiplication de bandes de fréquences à couvrir à conduit au développement intensif d’antennes reconfigurables en fréquence. La variation de la tension de polarisation des composants permet, alors, de commander la fréquence de résonnance de l’antenne et couvrir, ainsi, de larges bandes de fréquences. La mise au point de ce dispositif complexe nécessite l’utilisation d’un simulateur globale pouvant modéliser l’interaction entre l’antenne et le composant. Le simulateur peut aussi nous aider à optimiser la ou les positions du ou des composants sur l’antenne afin d’atteindre, au niveau du comportement de élément, des performances maximales. La méthode TLM (Transmission Line Matrix) a été développée sur des calculateurs parallèles afin de satisfaire à ces besoins ? Couplée à l’algorithme de Newton-Rhapson, des composants passifs (R, L, C) et actifs (diodes PIN, Schottky, varicap) ont été modélisés à l’aide d’éléments localisés et de leurs schémas électriques équivalents ? Les éléments parasites, introduits par le boîtier et autres contact ohmiques, ont été pris en compte ainsi que les dimensions réelles des composants. Les simulations et les mesures de plusieurs antennes actives commutables en fréquence sont présentées dans ce manuscrit, et ont permis de mettre en évidence l’efficacité du logiciel de simulation développéActive antennas are compact radiating structures including active devices to allow analog functions as oscillation, amplification, mixing, switching, etc. In active antennas, the active devices are placed inside the radiating element to avoid added noise and ohmic losses due to the transmission lines. In particular, due to the multiplicity of standards of telecommunications, broad-band micro-strip antennas are of great interest and can be designed by integrating switch components? The bias voltage control of the active devices allows to shift the antenna’s resonance frequency and to cover several frequency bands. In such structures, the behaviour of the passive element is strongly affected by the active device and global modelling is needed for an accurate design. The objective of this work was to develop, on parallel computing, a numerical 3D-TLM method (Transmission Line Matrix) to provide accurate simulation of reconfigurable printed antennas. Coupled with the algorithm of Newton-Rhapson, passive (R, L, C) and non linear active devices (diodes PIN, Schottky, varicap) were modelled as lumped elements and using their equivalent electric models. The parasitic elements, introduced by the ohmic case and other contacts, were taken into account as well as real dimensions of the components. Simulated and measured data of several commutable active antennas in frequency are presented in order to validate this efficient simulation tool
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Belhadj, Amor Zeineb. "Validation de systèmes sur puce complexes du niveau transactionnel au niveau transfert de registres." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT083/document.
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Cette thèse se situe dans le contexte de la vérification fonctionnelle des circuits intégrés complexes. L’objectif de ce travail est de créer un flot de vérification conjoint au flot de conception basé sur une technique appelée "vérification basée sur les assertions(ABV)". Le concept de base du flot est le raffinement automatique des spécifications formelles données sous la forme d’assertions PSL du niveau TLM au niveau RTL. La principale difficulté est la disparité des deux domaines : au niveau TLM, les communications sont modélisées par des appels de fonctions atomiques. Au niveau RTL, les échanges sont assurés par des signaux binaires évoluant selon un protocole de communication précis. Sur la base d’un ensemble de règles de transformation temporelles formelles, nous avons réalisé un outil permettant d’automatiser le raffinement de ces spécifications. Comme le raffinement des modèles, le raffinement des assertions n’est pas entièrement automatisable : des informations temporelles et structurelles doivent être fournies par l’utilisateur. L’outil réalise la saisie de ces informations de façon ergonomique, puis procède automatiquement à la transformation temporelle et structurelle de l’assertion. Il permet la génération d’assertions RTL mais aussi hybrides. Les travaux antérieurs dans ce domaine sont peu nombreux et les solutions proposées imposent de fortes restrictions sur les assertions considérées. À notre connaissance, le prototype que nous avons mis en oeuvre est le premier outil qui réalise un raffinement temporel fondé sur la sémantique formelle d’un langage de spécification standard (PSL)The context of this thesis is the functional verification of complex integrated circuits.The objective of our work is to create a seamless verification flow joint to the design flowand based on a proved technique called Assertions-Based Verification (ABV). The mainchallenge of TLM to RTL refinement is the disparity of these two domains : at TLM,communications are modeled as atomic function calls handling all the exchanged data.At RTL, communications are performed by signals according to a specific communicationprotocol. The proposed temporal transformation process is based on a set of formaltransformation rules. We have developed a tool performing the automatic refinement ofPSL specifications. As for design refinement assertion refinement is not fully automated.Temporal and structural information must be provided by the user, using an ergonomicinterface. The tool allows the generation of assertions in RTL but also hybrid assertions.Little work has been done before in this area, and the proposed solutions suffer from severerestrictions. To our knowledge, our prototype is the first tool that performs a temporaltransformation of assertions based on the formal semantics of a standard specificationlanguage (PSL)
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Viaud, Emmanuel. "Modélisation SystemC d'architectures multi-processeurs intégrées sur puce au niveau transactionnel avec représentation du temps." Paris 6, 2009. http://www.theses.fr/2009PA066118.
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Cette thèse présente les principes théoriques et l'implémentation pratique d'une méthode originale de modélisation transactionnelle avec temps (Transaction Level Modeling with Time, TLM-T) de plates-formes numériques multi-processeurs complexes à mémoire partagée. S'appuyant sur le niveau d'abstraction TLM (standard de l'Open SystemC Initiative), cette méthode rend possible l'exploration architecturale et facilite le développement du logiciel embarqué, tout en considérant les phénomènes de contention dynamique ignorés par TLM qui impactent grandement les performances temporelles. La méthode présentée permet d'obtenir un gain d'un ordre de grandeur par rapport à la simulation précise au cycle tout en gardant une précision temporelle des résultats obtenus de l'ordre de 5%.
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Domínguez, Almaguer Hugo Armando. "Contribuição ao método da modelagem por linhas de transmissão (TLM) e sua aplicação aos estudos em bioeletromagnetismo." Florianópolis, SC, 2003. http://repositorio.ufsc.br/xmlui/handle/123456789/85880.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.Made available in DSpace on 2012-10-21T00:38:51Z (GMT). No. of bitstreams: 1 192680.pdf: 9753454 bytes, checksum: 43e3fc9700aae2c0f2ea0874eb4deb93 (MD5)
O foco principal dos estudos do presente trabalho está dirigido ao desenvolvimento e implementação do método da modelagem numérica por Linhas de Transmissão (TLM) e à aplicação do mesmo em problemas de interação dos campos de radiofreqüência (RF) com os meios biológicos. São apresentados em detalhes os aspectos fundamentais das versões bi e tridimensionais do método TLM tradicional. É realizada a implementação de malhas irregulares (do tipo graded mesh) para as duas topologias TLM-2D, contornando assim as limitações impostas pelo aspecto geométrico da malha tradicional. Os algoritmos são adaptados para o tratamento de meios com perdas, obtendo-se um equacionamento que garante a simulação de inúmeros problemas de propagação de ondas eletromagnéticas em estruturas de geometria arbitrária, sempre que os meios sejam lineares, isotrópicos e não dispersivos. São abordados também os principais aspectos teóricos do fenômeno da interação dos campos de RF com os meios biológicos. Para a modelagem no domínio do tempo de fenômenos envolvendo meios dispersivos, é estudada a formulação TLM modificada (2D e 3D), utilizando técnicas de Transformada Z. O método assim reformulado permite a manipulação direta no domínio do tempo das equações com parâmetros dependentes da freqüência. O equacionamento do TLM dispersivo é condicionado para o tratamento de meios dielétricos de primeira ordem (materiais de Debye), que é o caso dos meios biológicos. Três exemplos de aplicações em bioeletromagnetismo são estudadas para testar as potencialidades do TLM. Os resultados das simulações foram altamente satisfatórios, mostrando assim a eficácia do método como ferramenta de cálculo para a modelagem deste tipo de problema.
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Makhlouf, Oualid. "Nouveau modèle TLM thermique pour la dosimétrie numérique de structures fortement hétérogènes." Thesis, Université Côte d'Azur (ComUE), 2016. http://www.theses.fr/2016AZUR4123/document.
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Depuis plusieurs années, le développement des technologies sans fil utilisant les ondes électromagnétiques dans différents milieux d’applications (télécommunications, médicales, militaires) ne cesse d’augmenter. Il devient donc nécessaire d’évaluer les effets de l’environnement sur les antennes en amont de leur conception afin d’optimiser la transmission entre les divers objets connectés. De plus, les études sur les systèmes utilisant les ondes électromagnétiques amènent à se poser un certain nombre de questions autour de l’interaction ondes/vivant, nous obligeant à considérer des modèles fortement hétérogènes tel que le corps humain.Face aux difficultés de mesures, la simulation permet de quantifier numériquement la puissance absorbée par les tissus au travers du DAS et l’élévation de la température correspondante. Dans ce domaine, la méthode TLM (Transmission Line Matrix) s’est révélée être particulièrement adaptée au calcul du DAS dans des structures fortement hétérogènes grâce à la colocalisation des champs au centre de la maille.Au cours de cette thèse, un outil basé sur la méthode TLM permettant d’effectuer des études dosimétriques en calculant le DAS et la température dans des milieux fortement hétérogènes a été développé. La première étape a été consacrée au développement d’un « module »pour calculer la DAS et la mise en place d’une interface pour lire les modèles voxélisés. Ensuite, un solveur thermique basé sur la TLM a été développé afin de simuler la température dans des milieux biologiques exposés aux ondes EM. Enfin, la comparaison avec le logiciel commercial CST a permis de valider notre outil et de l’appliquer par la suite pour étudier l’exposition d’une tête humaine au rayonnement d’un Smartphone modélisé par une PIFA fonctionnant à 900MHzFor several years, the development of the wireless technologies using the electromagnetic waves in various applications (telecommunications, medical, military …) does not stop increasing. Thus, it becomes necessary to evaluate the effects of the environment on antennas upstream to their conception to optimize the transmission between diverse connected objects. Furthermore, studies on the systems using the electromagnetic waves lead to ask a number of questions about waves/living interaction, obliging us to consider highly heterogeneous models such as human body.In front of difficulties of measures, the simulation allows to quantify numerically the power absorbed by tissues and the corresponding temperature rise. In this domain, the TLM method (Transmission Line Matrix) has proved to be particularly adapted to the simulation of the SAR in highly heterogeneous structures thanks to the co-localisation of the fields at the centre of mesh.In this thesis, a tool based on the TLM method to make dosimetrics studies by calculating the SAR and the temperature in highly heterogeneous media has been developed. The first step was dedicated to the development of a “module” to calculate the SAR and the implementation of an interface to read the voxelized models. Then, a thermal solver based on the TLM was developed in order to simulate the temperature in biological media exposed to the EM waves. Finally, the comparison with the commercial software CST allowed to validate our tool and to apply it afterward to study the exposure of a human head to the radiation of a Smartphone modelled by a PIFA antenna operating at 900MHz
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Jonutis, Vytautas, and Mindaugas Jaraminas. "Vaizdų atpažinimo sistemos projektavimas ir tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080811_151809-23043.
Full textAbstract:
Darbe analizuojamas vaizdo apdorojimo sistemos modelis, kuris yra modeliuojamas. Pradinė modelio specifikacija yra aprašoma funkciniame lygyje. Modelio architektūrai modeliuoti mes naudojame transakcijų lygio SystemC, naudodamiesi ja mes galime greitai ir patogiai nustatyti, kokia turėtų būti modeliuojamos sistemos architektūra. Funkcinis modelis yra transformuojamas į sisteminį lygį naudojantis SystemC transakcijų modeliavimo kalba. Naudojantis pradine specifikacija ir TLM modeliu pereiname prie sintezuojamo aprašo. Transformuodami pradinį modelį aukštame abstrakcijos lygyje, mes sprendžiame sistemos architektūros problemą. Transformuodami aukšto lygio modelį į SystemC sintezuojamą aprašą, mes sprendžiame kintamųjų ir algoritmų transformavimo problemas.In this work we analyzing video preprocessing system model. Primary model specifications are described in functional level. It is hard to decide what system architecture should be, so we used SystemC TLM modeling language, because it gives us easier way to change system architecture Using SystemC transaction level modeling (TLM) the functional primary specification are transformed from functional model to system level. To get synthesizable model we use primary specification and TLM model. We solve many system architecture problems while we where working on primary model transformation to high abstraction system. Transforming high abstraction level model to SystemC synthesizable code we solve variables selection problems and algorithms conversation problem.
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Chu, H. S. "Couplages algorithmes génétiques et TLM pour la conception des antennes imprimées miniatures." Phd thesis, Université de Nice Sophia-Antipolis, 2004. http://tel.archives-ouvertes.fr/tel-00454611.
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Cette étude contribue à la recherche de formes originales et non intuitives d'antennes miniatures. Il s'agit du développement et de l'application d'un code de calcul associant la simulation électromagnétique TLM (Transmission Line Matrix) à un Algorithme Génétique (AG). La partie théorique présente d'une part la méthode TLM et d'autre part les algorithmes génétiques. La méthode TLM, sur calculateur parallèle, permet d'analyser en 3 dimensions des antennes miniatures de formes arbitraires. Ses évolutions successives sont présentées avec l'objectif d'un couplage avec les algorithmes génétiques. Ceux-ci s'inspirent d'une technique d'optimisation stochastique basée sur la sélection naturelle et l'evolution des espèces. Une présentation définissant les grandeurs fondamentales à nos développements est effectuée. Dans la partie suivante, le couplage AG/TLM est décrit. La conception d'antennes, de formes intuitives ou non, est proposée pour deux types d'antennes bien connues, large bande et bi-bande. Il est ensuite propose un micro-algorithme génétique et son couplage avec la TLM (mAG/TLM) permettant d'atteindre une convergence plus rapide vers la solution optimale et d'éviter des convergences prématurées. Le code mAG/TLM a été appliqué à la recherche d'antennes imprimées, pour les normes WLAN2450 et HIPERLAN5250. Plusieurs antennes obtenues, chaque configuration dépend des conditions imposées sur les conditions initiales et sur la définition de la fonction ''objectif'', portant sur l'adaptation. Une étude expérimentale et de comparaisons systématique avec des logiciels commerciaux a été également développée. Enfin, dans la dernière partie, on s'est attache a l'optimisation d'antennes de type PIFA permettant de couvrir plusieurs standards, GSM, DCS, PCS, UMTS ou WLAN. Des résultats originaux sont proposes. En dernier lieu, des antennes filsplaques mono-polaires répondant aux standards WLAN/HIPERLAN2 et UMTS/HIPARLAN2 ont été obtenus.
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Nielsen, Jorgen Staal. "TLM analysis of microwave and millimeter wave structures with embedded nonlinear devices." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7751.
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A methodology has been developed such that electromagnetic structures with embedded non-linear devices can be accurately analyzed by the three-dimensional (3D) condensed node TLM algorithm. The method is based on incorporating a variable time step differential equation integration scheme, simulating the electrical behaviour of the devices, into the 3D TLM electromagnetic field simulation algorithm. The scheme can accommodate existing piece-wise linear SPICE device models of arbitrary complexity without non-physical instabilities or other spurious behaviour. A set of new 3D TLM node structures have been developed to complement the condensed node to better model the field at sharp conductor strip edges. These node structures provide substantial improvement in the accuracy of modelling strip-like transmission-line structures with a coarse mesh. They also provide a direct interface to the device model resulting in a more accurate simulation of the driving point impedance as seen by the device. A propagation analysis of the TLM condensed node was performed resulting in a derivation of the general dispersion relation. The superior dispersion characteristics of the condensed node relative to other TLM and FD-TD formulations was demonstrated based on the dispersion equation. Further exploration of the dispersion equation led to the discovery and characterization of spurious modes supported by the condensed node mesh. A derivation of the recursion equations of the equivalent FD-TD scheme representing the condensed node was then performed to establish the origin of the spurious modes and methods of suppressing them.
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Cascio, Lucia. "Modeling of nonlinear active and passive devices in three-dimensional TLM networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0003/NQ34254.pdf.
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Langley, Philip. "Numerical modelling of the deformation of elastic material by the TLM method." Thesis, University of Hull, 1997. http://hydra.hull.ac.uk/resources/hull:10448.
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The transmission line matrix (TLM) method is a numerical tool for the solution of wave and diffusion type equations. The application of TLM to physical phenomena such as heat flow and electromagnetic wave propagation is well established. A previous attempt to apply TLM models to the area of elastic wave propagation and elastic deformation had limited success. The work of this thesis extends the application base of TLM to the area of elastic deformation modelling and validates the model for several two-dimensional situations. In doing this it has been necessary to develop new nodal structures which facilitate the scaling of differential coefficients and incorporation of cross derivatives. Nodal structures which allow the modelling of two and three-dimensional, and anisotropic, elastic deformation are described. The technique is demonstrated by applying the elastic deformation model to several elastic problems. These include two-dimensional isotropic models and models of anisotropic elastic deformation. Provision is also made for the application of various boundary conditions which include displacement, force and frictional boundaries.