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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Déploiement auto-adaptatif d'intergiciel sur plate-forme élastique / Self-adaptive deployment for middleware on elastic platform

Faye, Maurice-Djibril 10 November 2015 (has links)
Nous avons étudié durant cette thèse les moyens de rendre le déploiement d'un intergiciel auto-adaptatif. Le type d'intergiciel que nous avons considéré ici est hiérarchique (structure de graphe) et distribué. Chaque sommet du graphe modélise un processus qui peut être déployé sur une machine physique ou virtuelle d'une infrastructure de type grille/cloud, les arêtes modélisent des liens de communications entre processus. Il offre aux clients des services de calcul haute performance. Les infrastructures de grilles/cloud étant élastiques (perte et ajout de nœuds), un déploiement statique n'est pas la solution idéale car en cas de panne on risque de tout reprendre à zéro, ce qui est coûteux. Nous avons donc proposé un algorithme auto-stabilisant pour que l'intergiciel puisse retrouver un état stable sans intervention extérieure, au bout d'un temps fini, lorsqu'il est confronté à certains types de pannes. Les types de pannes que nous avons considérés sont les pannes transitoires (simulé par la perte de nœuds, l'ajout de nouveaux nœuds, la perte de liens entre deux nœuds). Pour évaluer ces algorithmes, nous avons conçu un simulateur. Les résultats des simulations montrent qu'un déploiement, sujet à des pannes transitoires, s'auto-adapte. Avant d'en arriver à la phase de programmation du simulateur, nous avons d'abord proposé un modèle d'infrastructure distribuée (ce modèle permet de décrire des environnements de type grille/cloud), un modèle pour décrire certains types d'intergiciels hiérarchiques et enfin un modèle pouvant décrire un intergiciel en cours d'exécution (processus déployés sur les machines). / We have studied the means to make a middleware deployment self-adaptive. Our use case middleware is hierarchical and distributed and can be modeled by a graph. A vertex models a process and an edge models a communication link between two processes. The middleware provides high performance computing services to the users.Once the middleware is deployed on a computing infrastructure like a grid or cloud, how it adapt the changes in dynamic environment? If the deployment is static, it may be necessary to redo all the deployment process, which is a costly operation. A better solution would be to make the deployment self-adaptive. We have proposed a rules-based self-stabilizing algorithm to manage a faulty deployment. Thus, after the detection of an unstable deployment, caused by some transients faults (joining of new nodes or deletion of existing nodes which may modify the deployment topology), the system will eventually recover a stable state, without external help, but only by executing the algorithm.We have designed an ad hoc discrete events simulator to evaluate the proposed algorithm. The simulation results show that, a deployment, subjected to transients faults which make it unstable, adapts itself. Before the simulator design, we had proposed a model to describe a distributed infrastructure, a model to describe hierarchical middleware and a model to describe a deployment, that is the mapping between the middleware processes and the hardware on which they are running on.
112

Teste baseado em modelos para serviços RESTful usando máquinas de estados de protocolos UML / Model-based testing of RESTful web services using UML protocol state machines

Pedro Victor Pontes Pinheiro 15 April 2014 (has links)
A Arquitetura Orientada a Serviços (SOA) é um estilo arquitetural formado por um conjunto de restrições que visa promover a escalabilidade e a flexibilidade de um sistema, provendo suas funcionalidades como serviços. Nos últimos anos, um estilo alternativo foi proposto e amplamente adotado, que projeta as funcionalidades de um sistema como recursos. Este estilo arquitetural orientado a recursos é chamado de REST. O teste de serviços web em geral apresenta vários desafios devido a sua natureza distribuída, canal de comunicação pouco confiável, baixo acoplamento e a falta de uma interface de usuário. O teste de serviços RESTful (serviços que utilizam o REST) compartilham estes mesmos desafios e ainda necessitam que suas restrições sejam obedecidas. Estes desafios demandam testes mais sistemáticos e formais. Neste contexto, o teste baseado em modelos (TBM) se apresenta como um processo viável para abordar essas necessidades. O modelo que representa o sistema deve ser simples e ao mesmo tempo preciso para que sejam gerados casos de teste com qualidade. Com base nesse contexto, este projeto de mestrado propõe uma abordagem baseada em modelos para testar serviços RESTful. O modelo comportamental adotado foi a máquina de estados de protocolos UML, capaz de formalizar a interface do serviço enquanto esconde o seu funcionamento interno. Uma ferramenta foi desenvolvida para gerar automaticamente os casos de teste usando critérios de cobertura de estados e transições para percorrer o modelo / Service Oriented Architecture (SOA) is an architectural style consisting of a set of restrictions aimed at promoting the scalability and flexibility of a system, providing its functionalities as services. In recent years, an alternative style was proposed and widely adopted, which designs the system\'s functionalities as resources. This resource oriented architectural style is called REST. In general, the test of web services has several challenges due to its distributed nature, unreliable communication channel, low coupling and the lack of a user interface. Testing RESTful web services (services that use REST) share these same challenges and also need to obey the REST constraints. These challenges require a more systematic and formal testing approach. In this context, model based testing presents itself as a viable process for addressing those needs. The model that represents the system should be simple and precise enough to generate quality test cases. Based on this context, this work proposes a model based approach to test RESTful web services. The behavioral model used was the UML protocol state machine, which is capable to provide a formalization of the service interface, while hiding its internal behaviour. A tool was developed to automatically generate test cases using the state and transition coverage criteria to traverse the model
113

Design of a Low-Cost Data Acquisition System for Rotordynamic Data Collection

Pellegrino, Gregory S 01 March 2019 (has links)
A data acquisition system (DAQ) was designed based on the use of a STM32 microcontroller. Its purpose is to provide a transparent and low-cost alternative to commercially available DAQs, providing educators a means to teach students about the process through which data are collected as well as the uses of collected data. The DAQ was designed to collect data from rotating machinery spinning at a speed up to 10,000 RPM and send this data to a computer through a USB 2.0 full-speed connection. Multitasking code was written for the DAQ to allow for data to be simultaneously collected and transferred over USB. Additionally, a console application was created to control the DAQ and read data, and MATLAB code written to analyze the data. The DAQ was compared against a custom assembled National Instruments CompactDAQ system. Using a Bentley-Nevada RK 4 Rotor Kit, data was simultaneously collected using both DAQs. Analysis of this data shows the capabilities and limitations of the low cost DAQ compared to the custom CompactDAQ.
114

Prohlížečová hra s umělou inteligencí / Browser Game with Artificial Intelligence

Moravec, Michal January 2019 (has links)
Thesis describes design and implementation of a web browser game, which can be played by multiple players via the internet. The main goal is to manage the economy, although players can cooperate (trading) or play against each other (battles). NoSQL database is used for persistent storage of progress, which is also described in the thesis. Apart from human players there are also agents/bots, which play the game autonomously via state machines generated by genetic algorithms. Paper describes design and functionality of either the genetic algorithms, but also the state machines.
115

Nástroje pro automatizaci workflow procesů / Tools for Automating the Workflow Processes

Vančura, Tomáš January 2008 (has links)
The the thesis deals with tools for workflow processes automation. It describes in general what workflow is. It also briefly describes tools such as MS BizTalk Server, SAP NetWeaver, IBM WebSphere, ORACLE BPEL. The main part deals with Windows Workflow Foundation. This tool is decribed in detail together with its parts workflow runtime, workflow instances and workflow activities. One part of the thesis is a application, which uses all the possibilities of Windows Workflow Foundation.
116

Zdroj vysokonapěťových pulzů pro elektroporaci buněk / High Voltage Pulse Generator for Electroporation of Cells

Puczok, Václav January 2016 (has links)
The main goal of this thesis is to design control board for the experimental electroporation device and to develop control firmware. The first chapter of this work focuses on the electroporation phenomenon itself. Behaviour of the cell model in external electrical field is described there as well as simulation and overview of how electroporation affects living tissue. It also explains the main requirements for parameters of the electroporation pulses as well as need for ECG synchronization. Furthermore, some remarks are given about novel high frequency electroporation method, which involves use of nanosecond bipolar high voltage pulse bursts. The second chapter briefly introduces commercial electroporation device called Nanoknife, including control part, power part, and it's limits. The third chapter consists of introduction of the novel experimental electroporation device developed at BUT. Power part of this device is discussed as well. Next chapter focuses on design of the control board for this device and also on description of the particular schematic parts. There is a control algorithm explanation in the fifth chapter of this thesis followed by the brief manual to machine operation.
117

Model-Based Software Engineering : Methodologies for Model-Code Synchronization in Reactive System Development / Model-Based Software Engineering : méthodologies pour la synchronisation entre modèle et code dans le développement de systèmes réactifs

Pham, Van Cam 12 January 2018 (has links)
Model-Based Software Engineering (MBSE) a été proposé comme une méthodologie prometteuse de développement de logiciels pour surmonter les limites de la méthodologie traditionnelle basée sur la programmation pour faire face à la complexité des systèmes embarqués. MBSE favorise l’utilisation de langages de modélisation pour décrire les systèmes d’une manière abstraite et fournit des moyens pour générer automatiquement de différents artefacts de développement, p.ex. code et documentation, à partir de modèles. Le développement d’un système complexe implique souvent de multiples intervenants qui utilisent différents outils pour modifier les artefacts de développement, le modèle et le code en particulier dans cette thèse. Les modifications apportées aux artefacts évoquent le problème de cohérence qui nécessite un processus de synchronisation pour propager les modifications apportées dans l’un artefact aux autres artefacts. Dans cette étude, le problème de la synchronisation des modèles d’architecture basés sur les éléments UML composite structure (UML-CS) et UML state machine (UML-SM) du langage de l’Unified Modeling Language (UML), et le code orienté objet est présenté. UML-CSs sont utilisés pour décrire l’architecture du logiciel basée sur les composants et UML-SMs pour les comportements discrets liés aux événements des systèmes réactifs. Le premier défi est de permettre une collaboration entre les architectes de logiciels et les programmeurs produisant de modèle et de code, en utilisant différents outils. Il soulève le problème de synchronisation où il existe de modifications simultanées des artefacts. En fait, il existe un écart de perception entre les langages à base de diagramme (langages de modélisation) et les langages textuels (langages de programmation). D’une part, les programmeurs préfèrent souvent utiliser la combinaison familière d’un langage de programmation et d’un environnement de développement intégré. D’autre part, les architectes logiciels, travaillant à des niveaux d’abstraction plus élevés, favorisent l’utilisation des modèles et préfèrent donc les langages à base de diagramme pour décrire l’architecture du système. Le deuxième défi est qu’il existe un écart d’abstraction significatif entre les éléments du modèle et les éléments du code: les éléments UML-CS et UML-SM sont au niveau d’abstraction plus élevé que les éléments du code. L’écart rend la difficulté pour les approches de synchronisation actuelles car il n’y a pas de façon facile de réflecter les modifications du code au modèle. Cette thèse propose une approche automatisée de synchronisation composée de deux principales contributions corrélées. Pour aborder le premier défi, on propose un patron méthodologique générique de synchronisation entre modèle et code. Il consiste en des définitions des fonctionnalités nécessaires et plusieurs processus qui synchronisent le modèle et le code en fonction de plusieurs scénarios définis où les développeurs utilisent différents outils pour modifier le modèle et le code. Cette contribution est indépendante de UML-CSs et UML-SMs. La deuxième contribution traite du deuxième défi et est basée sur les résultats de la première contribution. Dans la deuxième contribution, un mapping bidirectionnel est présentée pour réduire l’écart d’abstraction entre le modèle et le code. Le mapping est un ensemble de correspondances entre les éléments de modèle et ceux de code. Il est utilisé comme entrée principale du patron méthodologique générique de synchronisation entre modèle et code. Plus important, l’utilisation du mapping fournit les fonctionnalités définies dans la première contribution et facilite la synchronisation des éléments de UML-CS et UML-SM et du code. L’approche est évaluée au moyen de multiples simulations et d’une étude de cas. / Model-Based Software Engineering (MBSE) has been proposed as a promising software development methodology to overcome limitations of traditional programming-based methodology in dealing with the complexity of embedded systems. MBSE promotes the use of modeling languages for describing systems in an abstract way and provides means for automatically generating different development artifacts, e.g. code and documentation, from models. The development of a complex system often involves multiple stakeholders who use different tools to modify the development artifacts, model and code in particular in this thesis. Artifact modifications must be kept consistent: a synchronization process needs to propagate modifications made in one artifact to the other artifacts. In this study, the problem of synchronizing Unified Modeling Language (UML)-based architecture models, specified by UML composite structure (UML-CS) and UML state machine (UML-SM) elements, and object-oriented code is presented. UML-CSs are used for describing the component-based software architecture and UML-SMs for discrete event-driven behaviors of reactive systems. The first challenge is to enable a collaboration between software architects and programmers producing model and code by using different tools. This raises the synchronization problem of concurrent artifact modifications. In fact, there is a perception gap between diagram-based languages (modeling languages) and text-based languages (programming languages). On the one hand, programmers often prefer to use the more familiar combination of a programming language and an Integrated Development Environment. On the other hand, software architects, working at higher levels of abstraction, tend to favor the use of models, and therefore prefer diagram-based languages for describing the architecture of the system. The second challenge is that there is a significant abstraction gap between the model elements and the code elements: UML-CS andUML-SM elements are at higher level of abstraction than code elements. The gap makes current synchronization approaches hard to be applied since there is no easy way to reflect modifications in code back to model. This thesis proposes an automated synchronization approach that is composed of two main correlated contributions. To address the first challenge, a generic model-code synchronization methodological pattern is proposed. It consists of definitions of necessary functionalities and multiple processes that synchronize model and code based on several defined scenarios where the developers use different tools to modify model and code. This contribution is independent of UML-CSs and UML-SMs. The second contribution deals with the second challenge and is based on the results from the first contribution. In the second contribution, a bidirectional mapping is presented for reducing the abstraction gap between model and code. The mapping is a set of correspondences between model elements and code elements. It is used as main input of the generic model-code synchronization methodological pattern. More importantly, the usage of the mapping provides the functionalities defined in the first contribution and eases the synchronization of UML-CS and UML-SM elements and code. The approach is evaluated by means of multiple simulations and a case study.
118

Dosis: din smarta pillerdosa : Utveckling av ett inbyggt system för en dosettask / Dosis: your smart pill dispenser : Development of an embedded system for a pilldispenser

Kleyer, Oskar, Holmlund, Fredrik January 2018 (has links)
Modern medicinering medför att patienter kan behandlas mer effektivt om den tas pårätt sätt. När patienter själva ansvarar för sin medicinering kan den feldoseras ellerglömmas bort, vilket ändrar förutsättningar för dess inverkan. Glömska kombineradmed sinnesnedsättningar försvårar för patienten att sköta sin medicinering.Lösningen på detta problem är idag utökad hemvård där vårdpersonal hjälper patientenatt ta rätt medicin vid rätt tidpunkt. En teknisk lösning kan vara ett inbyggt systemsom påminner patienten, sparar missade doseringar och kan därmed ge mer informationtill läkare som då kan göra mer välgrundade beslut för fortsatt vård.Resultaten visar att en dosettask kan användas för att påminna patienter att ta sinmedicin och skicka missad dosering med närfältskommunikation. Som mikrokontrolleranvändes en STM32 Nucleo, med en tillståndsmaskin som mjukvarulösning. I vidarestudier kan ett realtidsoperativsystem användas. Systemet programmerades medArduinos utvecklingsmiljö, men ett alternativ är IAR. Projektets prototyp kunde medde flesta modulerna uppnå specifikationens batteritid, utöver ljudmodulen som användes.För att komma fram till detta resultat skapades två teoretiska extremfall därprototypen testades.Dosettasken kan leda till minskat pillersvinn och en lägre kostnad då färre hembesökkrävs. Dessutom resulterar detta i ökad självständighet för patienten. Dessa faktorerleder till att dosettasken bidrar till en ökad hållbar utveckling. / Modern medication allows patients to be treated more efficiently if taken properly.When patients themselves are responsible for their medication, it can be wronglydosed or forgotten, which changes the conditions for its effects. Forgetfulness combinedwith impaired senses make it difficult for the patient to take care of his medication.The solution to this problem today is increased home care, where healthcare professionalshelp patients to take the right medication at the right time. A technical solutioncan be an embedded system that reminds the patient, saves missed dosages, and canprovide more information to doctors who can make more informed decisions for furthercare.The results show that a pill dispenser can be used to remind patients to take their medicationand send missed dosages with near field communication. As a microcontroller,a STM32 Nucleo was used, with a state machine as software solution. In further studies,a real-time operating system can be used. The system was programmed with Arduino'sdevelopment environment, but an alternative is IAR. The prototype of the projectcould achieve the specifications battery life with most modules, except to thesound module used. To achieve this result, two theoretical extremes were created inwhich the prototype was tested.The pill dispenser can lead to reduced waste of pills and a lower cost, as fewer homevisits are required. In addition, this results in increased independence for the patient.These factors cause the pill dispenser to contribute to increased sustainable development.
119

Distributed Consensus: Performance Comparison of Paxos and Raft / Distribuerad Konsensus: Prestandajämförelse mellan Paxos och Raft

Ng, Harald January 2020 (has links)
With the growth of the internet, distributed systems have become increasingly important in order to provide more available and scalable applications. Con- sensus is a fundamental problem in distributed systems where multiple pro- cesses have to agree on the same proposed value in the presence of partial failures. Distributed consensus allows for building various applications such as lock services, configuration manager services or distributed databases.Two well-known consensus algorithms for building distributed logs are Multi-Paxos and Raft. Multi-Paxos was published almost three decades before Raft and gained a lot of popularity. However, critics of Multi-Paxos consider it difficult to understand. Raft was therefore published with the motivation of being an easily understood consensus algorithm. The Raft algorithm shares similar characteristics with a practical version of Multi-Paxos called Leader- based Sequence Paxos. However, the algorithms differ in important aspects such as leader election and reconfiguration.Existing work mainly compares Multi-Paxos and Raft in theory, but there is a lack of performance comparisons in practice. Hence, prototypes of Leader- based Sequence Paxos and Raft have been designed and implemented in this thesis. The prototypes were implemented using the Rust programming lan- guage and the message-passing framework Kompact and then benchmarked in real-world scenarios to compare the performance of Leader-based Sequence Paxos and Raft.The results show that Leader-based Sequence Paxos and Raft have simi- lar performance in geographically distributed deployments. However, the un- predictable leader election in Raft could greatly affect the performance if the elected leader is in an undesired location. In our experiments, the location of the Raft leader affected the average throughput by up to 35%. Furthermore, the results indicate that implementation details could have a significant impact on performance even in the parts where the algorithms are similar. By batch- ing messages more efficiently, Leader-based Sequence Paxos achieved up to 17% higher average throughput than Raft. / Med tillväxten av internet har distribuerade system blivit allt mer viktiga för att bygga mer tillgängliga och skalbara applikationer. Konsensus är ett funda- mentalt problem i distribuerade system där flera processer ska komma överens om samma föreslagna värde, samtidigt som partiella fel kan ske. Distribuerad konsensus kan appliceras till olika användningsomården som låstjänster, kon- figurationshanterare och distribuerade databaser.Två välkända konsensusalgoritmer för att bygga distribuerade loggar är Multi-Paxos och Raft. Multi-Paxos publicerades nästintill tre årtionden före Raft och blev populär. Men kritiker av Multi-Paxos anser att algoritmen är svår att förstå. Av denna anledning publicerades Raft med motivationen att vara en konsensusalgoritm som är enkel att förstå. Raft delar likheter med Leader- based Sequence Paxos, en praktisk version av Multi-Paxos. Dock skiljer sig algoritmerna i viktiga aspekter som leaderval och rekonfigurering.Befintliga arbeten jämför i huvudsak Multi-Paxos och Raft i teorin, men det saknas jämförelse av prestandan i praktiken. Av denna anledning har pro- totyper av Leader-based Sequence Paxos och Raft blivit designade och imple- menterade i denna avhandling. Dessa prototyper implementerades i program- meringsspråket Rust och message-passing ramverket Kompact, som sedan tes- tades i verkliga situationer för att jämföra Leader-based Sequence Paxos och Raft.Resultaten visar att Leader-based Sequence Paxos och Raft har liknande prestanda i geografiskt distribuerade sammanhang. Dock kan det oförutsäga- bara ledarvalet i Raft påverka prestandan avsevärt ifall den valde ledaren befin- ner sig på en oönskad plats. I våra experiment påverkade Raft ledarens plats den genomsnittliga kapaciteten med upp till 35%. Resultaten visar även att implementationsdetaljer kan ha en signifikant effekt på prestandan även i de delar där algoritmerna är liknande. Genom att sammanfoga meddelanden mer effektivt uppnådde Leader-based Sequence Paxos 17% högre genomsnittlig kapacitet än Raft.
120

Sensory input encoding and readout methods for in vitro living neuronal networks

Ortman, Robert L. 06 July 2012 (has links)
Establishing and maintaining successful communication stands as a critical prerequisite for achieving the goals of inducing and studying advanced computation in small-scale living neuronal networks. The following work establishes a novel and effective method for communicating arbitrary "sensory" input information to cultures of living neurons, living neuronal networks (LNNs), consisting of approximately 20 000 rat cortical neurons plated on microelectrode arrays (MEAs) containing 60 electrodes. The sensory coding algorithm determines a set of effective codes (symbols), comprised of different spatio-temporal patterns of electrical stimulation, to which the LNN consistently produces unique responses to each individual symbol. The algorithm evaluates random sequences of candidate electrical stimulation patterns for evoked-response separability and reliability via a support vector machine (SVM)-based method, and employing the separability results as a fitness metric, a genetic algorithm subsequently constructs subsets of highly separable symbols (input patterns). Sustainable input/output (I/O) bit rates of 16-20 bits per second with a 10% symbol error rate resulted for time periods of approximately ten minutes to over ten hours. To further evaluate the resulting code sets' performance, I used the system to encode approximately ten hours of sinusoidal input into stimulation patterns that the algorithm selected and was able to recover the original signal with a normalized root-mean-square error of 20-30% using only the recorded LNN responses and trained SVM classifiers. Response variations over the course of several hours observed in the results of the sine wave I/O experiment suggest that the LNNs may retain some short-term memory of the previous input sample and undergo neuroplastic changes in the context of repeated stimulation with sensory coding patterns identified by the algorithm.

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