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When designing architectures and protocols for data traffic requiring real-time services, one of the major design goals is to guarantee that traffic deadlines can be met. However, many real-time applications also have additional requirements such as high throughput, high reliability, or energy efficiency. High-performance embedded systems communicating heterogeneous traffic with high bandwidth and strict timing requirements are in need of more efficient communication solutions, while wireless industrial applications, communicating control data, require support of reliability and guarantees of real-time predictability at the same time. To meet the requirements of high-performance embedded systems, this thesis work proposes two multi-wavelength high-speed passive optical networks. To enable reliable wireless industrial communications, a framework in­corporating carefully scheduled retransmissions is developed. All solutions are based on a single-hop star topology, predictable Medium Access Control algorithms and Earliest Deadline First scheduling, centrally controlled by a master node. Further, real-time schedulability analysis is used as admission control policy to provide delay guarantees for hard real-time traffic. For high-performance embedded systems an optical star network with an Arrayed Waveguide Grating placed in the centre is suggested. The design combines spatial wavelength re­use with fixed-tuned and tuneable transceivers in the end nodes, enabling simultaneous transmis­sion of both control and data traffic. This, in turn, permits efficient support of heterogeneous traf­fic with both hard and soft real-time constraints. By analyzing traffic dependencies in this mul­tichannel network, and adapting the real-time schedulability analysis to incorporate these traffic dependencies, a considerable increase of the possible guaranteed throughput for hard real-time traffic can be obtained. Most industrial applications require using existing standards such as IEEE 802.11 or IEEE 802.15.4 for interoperability and cost efficiency. However, these standards do not provide predict­able channel access, and thus real-time guarantees cannot be given. A framework is therefore de­veloped, combining transport layer retransmissions with real-time analysis admission control, which has been adapted to consider retransmissions. It can be placed on top of many underlying communication technologies, exemplified in our work by the two aforementioned wireless stan­dards. To enable a higher data rate than pure IEEE 802.15.4, but still maintaining its energy saving properties, two multichannel network architectures based on IEEE 802.15.4 and encompassing the framework are designed. The proposed architectures are evaluated in terms of reliability, utiliza­tion, delay, complexity, scalability and energy efficiency and it is concluded that performance is enhanced through redundancy in the time and frequency domains.

This item contains the agenda, minutes, and attachments for the Faculty Senate meeting on this date. There may be additional materials from the meeting available at the Faculty Center.

[ES] La constante necesidad de un mayor rendimiento para cumplir con la gran demanda de potencia de cómputo de las nuevas aplicaciones, (ej. sistemas de conducción autónoma), obliga a la industria a apostar por la tecnología basada en Sistemas en Chip con Procesadores Multinúcleo (MPSoCs) en sus sistemas embebidos de seguridad-crítica. Los sistemas MPSoCs generalmente incluyen una red en el chip (NoC) para interconectar los núcleos de procesamiento entre ellos, con la memoria y con el resto de recursos compartidos. Desafortunadamente, el uso de las NoCs dificulta alcanzar la predecibilidad en el tiempo, ya que pueden aparecer conflictos en muchos puntos y de forma distribuida a nivel de red. Para afrontar este problema, en esta tesis se propone un nuevo paradigma de diseño para NoCs de tiempo real donde los conflictos en la red son eliminados por diseño. Este nuevo paradigma parte del Grafo de Dependencia de Canales (CDG) para evitar los conflictos de red de forma determinista. Nuestra solución es capaz de inyectar mensajes de forma natural usando un periodo TDM igual al límite teórico óptimo sin la necesidad de usar un proceso offline exigente computacionalmente. La red se ha integrado en un sistema multinúcleo basado en tiles y adaptado a su jerarquía de memoria. Como segunda contribución principal, proponemos un nuevo planificador dinámico y distribuido capaz de alcanzar un rendimiento pico muy cercanos a las NoC basadas en un diseño wormhole sin comprometer sus garantías de tiempo real. El planificador se basa en nuestro diseño de red para explotar sus propiedades clave. Los resultados de nuestra NoC muestran que nuestro diseño garantiza la predecibilidad en el tiempo evitando interferencias en la red entre múltiples aplicaciones ejecutándose concurrentemente. La red siempre garantiza el rendimiento y también mejora el rendimiento respecto al de las redes wormhole en una red 4 x 4 en un factor de 3,7x cuando se inyecta trafico para generar interferencias. En una red 8 x 8 las diferencias son incluso mayores. Además, la red obtiene un ahorro de área total del 10,79% frente a una implementación básica de una red wormhole. El planificador propuesto alcanza una mejora de rendimiento de 6,9x y 14,4x frente la versión básica de la red DCFNoC para redes en forma de malla de 16 y 64 nodos, respectivamente. Cuando lo comparamos frente a un conmutador estándar wormhole se preserva un rendimiento de red del 95% al mismo tiempo que preserva la estricta predecibilidad en el tiempo. Este logro abre la puerta a nuevos diseños de NoCs de alto rendimiento con predecibilidad en el tiempo. Como contribución final, construimos una taxonomía de NoCs basadas en TDM con propiedades de tiempo real. Con esta taxonomía realizamos un análisis exhaustivo para estudiar y comparar desde tiempos de respuesta, a implementaciones con bajo coste, pasando por soluciones de compromiso para diseños de NoCs de tiempo real. Como resultado, obtenemos nuevos diseños de NoCs basadas en TDM. / [CA] La constant necessitat d'un major rendiment per a complir amb la gran demanda de potència de còmput de les noves aplicacions, (ex. sistemes de conducció autònoma), obliga la indústria a apostar per la tecnologia basada en Sistemes en Xip amb Processadors Multinucli (MPSoCs) en els seus sistemes embeguts de seguretat-crítica. Els sistemes MPSoCs generalment inclouen una xarxa en el xip (NoC) per a interconnectar els nuclis de processament entre ells, amb la memòria i amb la resta de recursos compartits. Desafortunadament, l'ús de les NoCs dificulta aconseguir la predictibilitat en el temps, ja que poden aparéixer conflictes en molts punts i de forma distribuïda a nivell de xarxa. Per a afrontar aquest problema, en aquesta tesi es proposa un nou paradigma de disseny per a NoCs de temps real on els conflictes en la xarxa són eliminats per disseny. Aquest nou paradigma parteix del Graf de Dependència de Canals (CDG) per a evitar els conflictes de xarxa de manera determinista. La nostra solució és capaç d'injectar missatges de mra natural fent ús d'un període TDM igual al límit teòric òptim sense la necessitat de fer ús d'un procés offline exigent computacionalment. La xarxa s'ha integrat en un sistema multinucli basat en tiles i adaptat a la seua jerarquia de memòria. Com a segona contribució principal, proposem un nou planificador dinàmic i distribuït capaç d'aconseguir un rendiment pic molt pròxims a les NoC basades en un disseny wormhole sense comprometre les seues garanties de temps real. El planificador es basa en el nostre disseny de xarxa per a explotar les seues propietats clau. Els resultats de la nostra NoC mostren que el nostre disseny garanteix la predictibilitat en el temps evitant interferències en la xarxa entre múltiples aplicacions executant-se concurrentment. La xarxa sempre garanteix el rendiment i també millora el rendiment respecte al de les xarxes wormhole en una xarxa 4 x 4 en un factor de 3,7x quan s'injecta trafic per a generar interferències. En una xarxa 8 x 8 les diferències són fins i tot majors. A més, la xarxa obté un estalvi d'àrea total del 10,79% front una implementació bàsica d'una xarxa wormhole. El planificador proposat aconsegueix una millora de rendiment de 6,9x i 14,4x front la versió bàsica de la xarxa DCFNoC per a xarxes en forma de malla de 16 i 64 nodes, respectivament. Quan ho comparem amb un commutador estàndard wormhole es preserva un rendiment de xarxa del 95% al mateix temps que preserva la estricta predictibilitat en el temps. Aquest assoliment obri la porta a nous dissenys de NoCs d'alt rendiment amb predictibilitat en el temps. Com a contribució final, construïm una taxonomia de NoCs basades en TDM amb propietats de temps real. Amb aquesta taxonomia realitzem una anàlisi exhaustiu per a estudiar i comparar des de temps de resposta, a implementacions amb baix cost, passant per solucions de compromís per a dissenys de NoCs de temps real. Com a resultat, obtenim nous dissenys de NoCs basades en TDM. / [EN] The ever need for higher performance to cope with the high computational power demands of new applications (e.g autonomous driving systems), forces industry to support technology based on multi-processors system on chip (MPSoCs) in their safety-critical embedded systems. MPSoCs usually include a network-on-chip (NoC) to interconnect the cores between them and, with memory and the rest of shared resources. Unfortunately, the inclusion of NoCs difficults achieving time predictability as network-level conflicts may occur in many points in a distributed manner. To overcome this problem, this thesis proposes a new time-predictable NoC design paradigm where conflicts within the network are eliminated by design. This new paradigm builds on top of the Channel Dependency Graph (CDG) in order to deterministically avoid network conflicts. Our solution is able to naturally inject messages using a TDM period equal to the optimal theoretical bound without the need of using a computationally demanding offline process. The network is integrated in a tile-based manycore system and adapted to its memory hierarchy. As a second main contribution, we propose a novel distributed dynamic scheduler that is able to achieve peak performance close to a wormhole-based NoC design without compromising its real-time guarantees. The scheduler builds on top of our NoC design to exploit its key properties. The results of our NoC show that our design guarantees time predictability avoiding network interference among multiple running applications. The network always guarantees performance and also improves wormhole performance in a 4 x 4 setting by a factor of 3.7x when interference traffic is injected. For a 8 x 8 network differences are even larger. In addition, the network obtains a total area saving of 10.79% over a standard wormhole implementation. The proposed scheduler achieves an overall throughput improvement of 6.9x and 14.4x over a baseline conflict-free NoC for 16 and 64-node meshes, respectively. When compared against a standard wormhole router 95% of its network throughput is preserved while strict timing predictability is kept. This achievement opens the door to new high performance time predictable NoC designs. As a final contribution, we build a taxonomy of TDM-based NoCs with real-time properties. With this taxonomy we perform a comprehensive analysis to study and compare from response time specific, to low resource implementation cost, through trade-off solutions for real-time NoCs designs. As a result, we derive new TDM-based NoC designs. / Picornell Sanjuan, T. (2021). Conflict-Free Networks on Chip for Real Time Systems [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/177347

Cette thèse s’inscrit dans le domaine mathématique de l’analyse des équations aux dérivées partielles (EDP) non-linéaires stochastiques. Nous nous intéressons à des EDP paraboliques et hyperboliques que l’on perturbe stochastiquement au sens d’Itô. Il s’agit d’introduire l’aléatoire via l’ajout d’une intégrale stochastique (intégrale d’Itô) qui peut dépendre ou non de la solution, on parle alors de bruit multiplicatif ou additif. La présence de la variable de probabilité ne nous permet pas d’utiliser tous les outils classiques de l’analyse des EDP. Notre but est d’adapter les techniques connues dans le cadre déterministe aux EDP non linéaires stochastiques en proposant des méthodes alternatives. Les résultats obtenus sont décrits dans les cinq chapitres de cette thèse : Dans le Chapitre I, nous étudions une perturbation stochastique des équations de Barenblatt. En utilisant une semi- discrétisation implicite en temps, nous établissons l’existence et l’unicité d’une solution dans le cas additif, et grâce aux propriétés de la solution nous sommes en mesure d’étendre ce résultat au cas multiplicatif à l’aide d’un théorème de point fixe. Dans le Chapitre II, nous considérons une classe d’équations de type Barenblatt stochastiques dans un cadre abstrait. Il s’agit là d’une généralisation des résultats du Chapitre I. Dans le Chapitre III, nous travaillons sur l’étude du problème de Cauchy pour une loi de conservation stochastique. Nous montrons l’existence d’une solution par une méthode de viscosité artificielle en utilisant des arguments de compacité donnés par la théorie des mesures de Young. L’unicité repose sur une adaptation de la méthode de dédoublement des variables de Kruzhkov.. Dans le Chapitre IV, nous nous intéressons au problème de Dirichlet pour la loi de conservation stochastique étudiée au Chapitre III. Le point remarquable de l’étude repose sur l’utilisation des semi-entropies de Kruzhkov pour montrer l’unicité. Dans le Chapitre V, nous introduisons une méthode de splitting pour proposer une approche numérique du problème étudié au Chapitre IV, suivie de quelques simulations de l’équation de Burgers stochastique dans le cas unidimensionnel. / This thesis deals with the mathematical field of stochastic nonlinear partial differential equations’ analysis. We are interested in parabolic and hyperbolic PDE stochastically perturbed in the Itô sense. We introduce randomness by adding a stochastic integral (Itô integral), which can depend or not on the solution. We thus talk about a multiplicative noise or an additive one. The presence of the random variable does not allow us to apply systematically classical tools of PDE analysis. Our aim is to adapt known techniques of the deterministic setting to nonlinear stochastic PDE analysis by proposing alternative methods. Here are the obtained results : In Chapter I, we investigate on a stochastic perturbation of Barenblatt equations. By using an implicit time discretization, we establish the existence and uniqueness of the solution in the additive case. Thanks to the properties of such a solution, we are able to extend this result to the multiplicative noise using a fixed-point theorem. In Chapter II, we consider a class of stochastic equations of Barenblatt type but in an abstract frame. It is about a generalization of results from Chapter I. In Chapter III, we deal with the study of the Cauchy problem for a stochastic conservation law. We show existence of solution via an artificial viscosity method. The compactness arguments are based on Young measure theory. The uniqueness result is proved by an adaptation of the Kruzhkov doubling variables technique. In Chapter IV, we are interested in the Dirichlet problem for the stochastic conservation law studied in Chapter III. The remarkable point is the use of the Kruzhkov semi-entropies to show the uniqueness of the solution. In Chapter V, we introduce a splitting method to propose a numerical approach of the problem studied in Chapter IV. Then we finish by some simulations of the stochastic Burgers’ equation in the one dimensional case.

Dans ce travail de thèse le processus d'information concernant un instant de défaut τ dans un modèle de risque de crédit est décrit par un pont brownien sur l'intervalle stochastique [0, τ]. Un tel processus de pont est caractérisé comme plus adapté dans la modélisation que le modèle classique considérant l'indicatrice I[0,τ]. Après l'étude des formules de Bayes associées, cette approche de modélisation de l'information concernant le temps de défaut est reliée avec d'autres informations sur le marché financier. Ceci est fait à l'aide de la théorie du grossissement de filtration, où la filtration générée par le processus d'information est élargie par la filtration de référence décrivant d'autres informations n'étant pas directement liées avec le défaut. Une attention particulière est consacrée à la classification du temps de défaut par rapport à la filtration minimale mais également à la filtration élargie. Des conditions suffisantes, sous lesquelles τ est totalement inaccessible, sont discutées, mais également un exemple est donné dans lequel τ évite les temps d'arrêt, est totalement inaccessible par rapport à la filtration minimale et prévisible par rapport à la filtration élargie. Enfin, des contrats financiers comme, par exemple, des obligations privée et des crédits default swaps, sont étudiés dans le contexte décrit ci-dessus. / In this PhD thesis the information process concerning a default time τ in a credit risk model is described by a Brownian bridge over the random time interval [0, τ]. Such a bridge process is characterised as to be a more adapted model than the classical one considering the indicator function I[0,τ]. After the study of related Bayes formulas, this approach of modelling information concerning the default time is related with other financial information. This is done with the help of the theory of enlargement of filtration, where the filtration generated by the information process is enlarged with a reference filtration modelling other information not directly associated with the default. A particular attention is paid to the classification of the default time with respect to the minimal filtration but also with respect to the enlarged filtration. Sufficient conditions under which τ is totally inaccessible are discussed, but also an example is given of a τ avoiding the stopping times of the reference filtration, which is totally inaccessible with respect to its own filtration and predictable with respect to the enlarged filtration. Finally, common financial contracts like defaultable bonds and credit default swaps are considered in the above described settings.

A utilização correta da jurisprudência conduzirá a sociedade brasileira a uma maior estabilidade jurisprudencial, com respeito ao princípio da isonomia, não somente diante da norma legislada como também perante a norma judicada. Deve-se afastar a discrepância de decisões judiciais relativas ao mesmo tema, que tratam desigualmente os iguais, evitando assim o longo percurso das vias recursais para se obter um julgamento isonômico em situações idênticas. O princípio da isonomia visa garantir que todos recebam tratamento igualitário da lei e, de outro lado, oferece a certeza de que todos os juízes devem decidir de modo análogo quando se depararem diante de situações semelhantes. A jurisprudência, uma vez que traduz a interpretação da norma, deve ser estável e previsível, com o fito de pautar as condutas dos jurisdicionados em virtude de se conhecer o entendimento da Corte máxima a respeito de uma determinada matéria. Um direito instável e imprevisível não gera a segurança jurídica, nem a pacificação social que razoavelmente se espera. A aplicação da jurisprudência no tempo, através da modulação, ganha novos contornos em virtude de sua previsão legal no projeto do Código de Processo Civil. A mudança de entendimento sedimentado observará a necessidade de fundamentação adequada e específica, considerando o imperativo de estabilidade das relações jurídicas (art. 847, 1 do projeto concluído no Senado Federal). Privilegia-se, além do princípio da segurança jurídica, o princípio da confiança que deve ter como uma das suas consequências que a expectativa legítima do jurisdicionado seja respeitada mediante a aplicação da jurisprudência dominante antiga e mais benéfica para o jurisdicionado. Neste contexto, em se pensando em uma reforma processual efetiva, deve-se ter como objetivo a ser seguido, além da celeridade processual e eficiência dos atos jurisdicionais, a uniformização da jurisprudência, eis que a necessidade de formação de uma só pauta de conduta para o jurisdicionado deve ser o objetivo almejado. E este objetivo só será alcançado quando houver uma uniformização e aplicação da jurisprudência dominante. Os instrumentos processuais inseridos no Código de Processo Civil devem ser reavaliados e novos elaborados, já que até agora serviram para dirimir conflitos intersubjetivos e não mais respondem satisfatoriamente às novas situações, que são as necessidades e valores de uma sociedade globalizada, massificada. / The correct use of case law will lead Brazilian society to a greater judicial stability that complies with the principle of equality, not only before legal rules as well as before judicial norms.It should be avoided the discrepancy of judgments related to the same matter, which unequally treat the ones in the same circumstances, thus avoiding the long judicial journey in order to obtain a uniform judgment for similar situations. The principle of equality aims to ensure that everyone receives equal law treatment and on the other hand, assures that all judges should decide in the same way when they come across similar situations. The jurisprudence as it reflects the interpretation of the rule, should be stable and predictable, in order to guide the conduct of citizens as it states the highest Court understanding on a particular matter. An unstable and unpredictable rule does not create lawl certainty nor the social peace that one can reasonably expect. The application of case law in time, by means of its modulation, earns new contours due its legal provision in the Civil Procedure Code Project. The change of a settled understanding claims for an adequate and specific reasoning, considering the need for stability of legal relations (art. 847, 1 of the completed project in the Senate). This increases the value of the legal certainty principle and of legitimate expectations principle that should have as one of their consequences that the legitimate expectation of the claimer is respected by applying him the old and more beneficial ruling jurisprudence. In this context, the aim for an effective procedural reform should be pursued, besides the procedural celerity and the efficiency of judicial acts, and also the standardization of jurisprudence. An unique agenda of conduct for the claimants should be desired as a goal. And this can only be achieved when there is a standardization and application of prevailing jurisprudence.

A utilização correta da jurisprudência conduzirá a sociedade brasileira a uma maior estabilidade jurisprudencial, com respeito ao princípio da isonomia, não somente diante da norma legislada como também perante a norma judicada. Deve-se afastar a discrepância de decisões judiciais relativas ao mesmo tema, que tratam desigualmente os iguais, evitando assim o longo percurso das vias recursais para se obter um julgamento isonômico em situações idênticas. O princípio da isonomia visa garantir que todos recebam tratamento igualitário da lei e, de outro lado, oferece a certeza de que todos os juízes devem decidir de modo análogo quando se depararem diante de situações semelhantes. A jurisprudência, uma vez que traduz a interpretação da norma, deve ser estável e previsível, com o fito de pautar as condutas dos jurisdicionados em virtude de se conhecer o entendimento da Corte máxima a respeito de uma determinada matéria. Um direito instável e imprevisível não gera a segurança jurídica, nem a pacificação social que razoavelmente se espera. A aplicação da jurisprudência no tempo, através da modulação, ganha novos contornos em virtude de sua previsão legal no projeto do Código de Processo Civil. A mudança de entendimento sedimentado observará a necessidade de fundamentação adequada e específica, considerando o imperativo de estabilidade das relações jurídicas (art. 847, 1 do projeto concluído no Senado Federal). Privilegia-se, além do princípio da segurança jurídica, o princípio da confiança que deve ter como uma das suas consequências que a expectativa legítima do jurisdicionado seja respeitada mediante a aplicação da jurisprudência dominante antiga e mais benéfica para o jurisdicionado. Neste contexto, em se pensando em uma reforma processual efetiva, deve-se ter como objetivo a ser seguido, além da celeridade processual e eficiência dos atos jurisdicionais, a uniformização da jurisprudência, eis que a necessidade de formação de uma só pauta de conduta para o jurisdicionado deve ser o objetivo almejado. E este objetivo só será alcançado quando houver uma uniformização e aplicação da jurisprudência dominante. Os instrumentos processuais inseridos no Código de Processo Civil devem ser reavaliados e novos elaborados, já que até agora serviram para dirimir conflitos intersubjetivos e não mais respondem satisfatoriamente às novas situações, que são as necessidades e valores de uma sociedade globalizada, massificada. / The correct use of case law will lead Brazilian society to a greater judicial stability that complies with the principle of equality, not only before legal rules as well as before judicial norms.It should be avoided the discrepancy of judgments related to the same matter, which unequally treat the ones in the same circumstances, thus avoiding the long judicial journey in order to obtain a uniform judgment for similar situations. The principle of equality aims to ensure that everyone receives equal law treatment and on the other hand, assures that all judges should decide in the same way when they come across similar situations. The jurisprudence as it reflects the interpretation of the rule, should be stable and predictable, in order to guide the conduct of citizens as it states the highest Court understanding on a particular matter. An unstable and unpredictable rule does not create lawl certainty nor the social peace that one can reasonably expect. The application of case law in time, by means of its modulation, earns new contours due its legal provision in the Civil Procedure Code Project. The change of a settled understanding claims for an adequate and specific reasoning, considering the need for stability of legal relations (art. 847, 1 of the completed project in the Senate). This increases the value of the legal certainty principle and of legitimate expectations principle that should have as one of their consequences that the legitimate expectation of the claimer is respected by applying him the old and more beneficial ruling jurisprudence. In this context, the aim for an effective procedural reform should be pursued, besides the procedural celerity and the efficiency of judicial acts, and also the standardization of jurisprudence. An unique agenda of conduct for the claimants should be desired as a goal. And this can only be achieved when there is a standardization and application of prevailing jurisprudence.