L’évolution des systèmes de communications sans fil a permis d’envisager de très nombreuses applications pour les systèmes de transport intelligents (ITS). Elles peuvent ou non utiliser une infrastructure et iront de la sécurité routière aux applications de confort du conducteur ou aux jeux en réseaux. La mise à jour de cartes constitue de notre point de vue une application représentative dans la mesure où ce n’est pas une application de sécurité en tant que telle, mais qu’en revanche elle peut contribuer à réduire les embouteillages en améliorant l’efficacité dans la prise de décisions des conducteurs. Elle possède des caractéristiques facilement identifiables : volume élevé de données, faible contrainte de délai, possibilité de mise en œuvre par des communications d’infrastructure à véhicule, entre véhicules, et hybrides. L’objectif est que les contenus soient téléchargés intégralement par tous les véhicules en un temps minimal, en utilisant le moins de ressources possible et au moindre coût. Les solutions qui sont apparues comme les plus adaptées ont concerné l’utilisation de solutions 802.11p avec ou sans infrastructure. Dans le cas de solutions avec infrastructure, un certain nombre de points d’accès diffuseront des informations avec des zones de couverture le plus souvent disjointes. Vu les tailles de zone retenues et/ou le débit consacré à ce type d’applications, le passage devant un seul point d’accès ne suffira pas à télécharger de telles cartes. Il s’agit alors de définir des stratégies de diffusion d’information. Une première étude a consisté à comparer une stratégie unicast à du broadcast/multicast. Cette dernière se révèle largement meilleure. Une combinaison de ces principes n’améliore pas les performances du système, car le débit consacré à la transmission unicast ne compense pas le débit non utilisé par le broadcast. Le problème provient des doublons reçus par les véhicules en passant auprès de plusieurs points d’accès consécutifs. Afin d’atténuer le phénomène des doublons, nous avons eu recours au Codage Réseau linéaire pseudo-aléatoire. L’idée est que le point d’accès diffuse des combinaisons linéaires de morceaux de fichiers. Le grand nombre de ces combinaisons linéaires réduit de façon significative ce phénomène. De façon complémentaire, nous avons étudié l’utilisation de communications ad-hoc pour combler les morceaux de fichier manquants, en particulier dans le cas d’absence d’infrastructure. Nous avons vérifié que l’on pouvait atteindre de bons résultats dans ce contexte en fonction de la diversité des morceaux de fichiers appartenant aux véhicules rencontrés. / The evolution of wireless communications systems have enabled to consider many applications for Intelligent Transportation Systems (ITS). They may or may not use the infrastructure. They will consider from the traffic safety applications up to the driver’s comfort or network games. The map updates are, from our point of view, a representative application but in the other hand it can help to reduce congestion in improving efficiency in decision making. It has well-defined characteristics : high volume of data, low delay constraint, possibility of implementation of infrastructure-to-vehicle communications, between vehicles and hybrids. The objective is that the contents are fully downloaded by all vehicles in minimum time, using fewer resources and lower costs. The solutions that have emerged as the most suitable concerned the use of the technology 802.11p with or without infrastructure. In the case of solutions with infrastructure, a number of access points broadcast information with coverage areas most often disjointed. Given the size of area used and/or flow devoted to this type of applications, the transition to a single access point is not enough to download these maps. It is then to define strategies of information dissemination. A first study was to compare a unicast strategy face to broadcast/multicast strategy. The latter appears largely improved. A combination of these principles does not improve system performance, because the flow devoted to unicast transmission does not compensate for the flow not used by the broadcast. The problem is duplicate chunks received by vehicles passing from several consecutive access points. To mitigate the phenomenon of duplication, we used the linear network coding pseudorandom. The idea is that the access point broadcasts linear combinations of chunks of files. The large number of these linear combinations significantly reduces this phenomenon. In a complementary manner, we investigated the use of ad hoc communications to fill the missing chunks of file, particularly in the absence of infrastructure. We verified that we could achieve good results in this context based on the diversity of chunks of files which are owned by the encountered vehicles.

Este trabalho é a narrativa de uma experiência didática de aplicação de um módulo que integrou o tópico de Supercondutividade no Ensino Médio regular de uma escola pública situada na cidade de Veranópolis, RS, sob o referencial teórico da Teoria dos Campos Conceituais de Gérard Vergnaud. Descrevem-se em detalhe as situações-problema e os recursos selecionados e utilizados, bem como a sequência de como o tema foi abordado no ensino regular, com turmas de terceiro ano. A forma como o módulo foi pensado e o nível de profundidade que foi possível alcançar aparecem ao longo do texto, que também oferece uma revisão da literatura em que a relevância da inclusão da Física Moderna e Contemporânea no currículo do Ensino Médio é discutida. O resultado indica que é possível trabalhar assuntos de Física Moderna e Contemporânea no ensino regular, que os alunos apreciam e mostram disposição para aprender assuntos atuais e que o esforço para introduzir pequenas atualizações curriculares é válido e precisa ser incentivado como uma das possíveis alternativas para se alcançar a melhoria de qualidade na Educação Básica. Ao final, um produto educacional em formato de texto de apoio, orientação e motivação aos professores de Física é apresentado. / This work is a narrative of an application teaching experience that composed the topic of Superconductivity in a Public High School located in Veranópolis city, RS, with the theoretical reference of the Conceptual Fields Theory from Gérard Vergnaud. The problem situations and the selected used resources are detailed described, as well the sequence like it was seen with high school third year students. The way the module was thought and the possible intensity level are throughout the text, which also offers a literature review where there are discussions about the relevance of the Modern and contemporary Physics inclusion in High School curriculum. The result indicates that it is possible to develop Modern and contemporary Physics issues in High School, because the students enjoy and cheer learning current topics, and that the effort to insert small curriculum changes is valid and needs to be encouraged as one possible solution to achieve the Basic Education quality improvement. At the end, it is presented an educational product as a supporting text, orientation and motivation to Physics’ teachers.

Este trabalho é a narrativa de uma experiência didática de aplicação de um módulo que integrou o tópico de Supercondutividade no Ensino Médio regular de uma escola pública situada na cidade de Veranópolis, RS, sob o referencial teórico da Teoria dos Campos Conceituais de Gérard Vergnaud. Descrevem-se em detalhe as situações-problema e os recursos selecionados e utilizados, bem como a sequência de como o tema foi abordado no ensino regular, com turmas de terceiro ano. A forma como o módulo foi pensado e o nível de profundidade que foi possível alcançar aparecem ao longo do texto, que também oferece uma revisão da literatura em que a relevância da inclusão da Física Moderna e Contemporânea no currículo do Ensino Médio é discutida. O resultado indica que é possível trabalhar assuntos de Física Moderna e Contemporânea no ensino regular, que os alunos apreciam e mostram disposição para aprender assuntos atuais e que o esforço para introduzir pequenas atualizações curriculares é válido e precisa ser incentivado como uma das possíveis alternativas para se alcançar a melhoria de qualidade na Educação Básica. Ao final, um produto educacional em formato de texto de apoio, orientação e motivação aos professores de Física é apresentado. / This work is a narrative of an application teaching experience that composed the topic of Superconductivity in a Public High School located in Veranópolis city, RS, with the theoretical reference of the Conceptual Fields Theory from Gérard Vergnaud. The problem situations and the selected used resources are detailed described, as well the sequence like it was seen with high school third year students. The way the module was thought and the possible intensity level are throughout the text, which also offers a literature review where there are discussions about the relevance of the Modern and contemporary Physics inclusion in High School curriculum. The result indicates that it is possible to develop Modern and contemporary Physics issues in High School, because the students enjoy and cheer learning current topics, and that the effort to insert small curriculum changes is valid and needs to be encouraged as one possible solution to achieve the Basic Education quality improvement. At the end, it is presented an educational product as a supporting text, orientation and motivation to Physics’ teachers.

There are no guidelines regarding how companies should design status updates on Facebook which attain good readability and engage the readers. Half the Swedish population are Facebook-users, but companies have yet to publish comprehensible messages on Facebook which effectively include the recipients. Inclusion is not just a matter of accessibility, but also of readability. Therefore, I studied how status updates should be designed on Facebook in order to increase the readability and to engage the readers. My target group is 22-32 year olds, since the company I worked with wanted to target this group. I conducted my research through literature studies, interviews with the client, analysis of past status updates, questioned an expert in social media, and organized a group interview with the target group. My research shows that status updates should contain information that is topical, informative and relevant to the target group. However, status updates should not contain too much information, since messages that are saturated with information are difficult for the audience to interact with. Status updates should be written seriously and give the readers an added value. The message should contain 50-250 characters. If the audience is unfamiliar with the subject in the status update, a longer message may be necessary. Nonetheless, status updates should not exceed 400 characters, as the readers will then lose interest. Status updates should be written in a simple and informal language. Communication on Facebook requires specific guidelines, since social media differs from traditional media. The texts published here must be specifically adapted to Facebook. This requires an increased understanding of the demands Facebook as a medium puts on texts published on this social utility. Further research could therefore explore the way in which people read on Facebook, for example by using eye-tracking cameras. / Det saknas riktlinjer för hur företag ska utforma läsbara statusuppdateringar på Facebook som engagerar läsarna. För att företag ska kunna inkludera sina mottagare kan de inte förlita sig på Facebooks fysiska tillgänglighet. Informationen som företag publicerar på Facebook måste också göras begriplig för läsarna. Därför studerade jag hur statusuppdateringar bör utformas på Facebook för att få hög läsbarhet och för att engagera läsarna. Min målgrupp är 22-32-åringar, eftersom företaget jag arbetade mot ville nå ut till denna grupp. Genom litteraturstudier, intervjuer med uppdragsgivaren, analys av tidigare statusuppdateringar, att ställa frågor till en expert på sociala medier samt genom en gruppintervju med målgruppen kom jag fram till mitt resultat. Min undersökning visar att innehållet i en statusuppdatering ska vara aktuellt, informativt och relevant för målgruppen. Statusuppdateringar får inte vara för uttömmande. De ska vara seriösa och ge läsaren ett mervärde. En statusuppdatering bör omfatta 50-250 tecken. Om läsarens är obekant med ämnet i uppdateringen kan den även vara längre. Statusuppdateringar bör dock inte överstiga 400 tecken, eftersom läsaren förlorar intresset då. Språket i en statusuppdatering får vara ledigt, men måste vara tydligt. Särskilda riktlinjer behövs för kommunikation på Facebook, eftersom sociala medier fungerar annorlunda än traditionella medier. De texter som publiceras på Facebook måste anpassas för Facebook. Därför krävs en bättre förståelse för de krav Facebook som medium ställer på texterna som publiceras där. Vidare forskning kunde därför studera hur människor läser på Facebook, exempelvis med hjälp av ögonrörelsekamera.

The effect of using the eventual consistency model is evaluated, compared to the effect of immediate consistency, by increasing the stabilization time in both models and using the immediate consistent system as a baseline for evaluations. The immediate consistent system performs better if the information and the decisions are replicated adequately fast throughout the system. When the stabilization time increases the effectiveness of eventual consistency emerges, which is most obvious when time constraints make it difficult to propagate information and decisions. By using a simulation to extract data for evaluations, it is verified in this research that as the stabilization time between different parts of a system increases, the eventual consistency will always outperform the immediate consistent system. This statement is valid in all situations where consistency models are useful. Of secondary importance in the research, by adding more decision layers to the eventual consistency model, the performance output is increased significantly, as swift and less well calculated decisions can be thwarted and corrected using the second decision layer.

The rapid growth of the Internet has resulted in the desperate need for alternative ways to keep electronic transactions secure while at the same time allowing entities that do not know each other to interact. This has, in turn, led to a wide area of interest in the issues of trust and trust modeling to be used by machines. A large amount of work has already been undertaken in this area in an attempt to transfer the trust and interaction decision making processes onto the machine. However this work has taken a number of different approaches with little to no correlation between various models and no standard set of criteria was even proposed that can be used to evaluate the value of such models. The proposed research chooses to use a detailed literature survey to investigate the current models in existence. This investigation focuses on identifying criteria that are required by trust models. These criteria are grouped into four categories that represent four important concepts to be implemented in some manner by trust models: trust representation, initial trust, trust update and trust evaluation. The process of identifying these criteria has led to a second problem. The trust evaluation process is a detailed undertaking requiring a high processing overhead. This process can either result in a value that allows an agent to trust another to a certain extent or in a distrust value that results in termination of the interaction. The evaluation process required to obtain the distrust value is just as process intensive as the one resulting in determining a level of trust and the constraints that will be placed on an interaction. This raises the question: How do we simplify the trust evaluation process for agents that have a high probability of resulting in a distrust value? This research solves this problem by adding a fifth category to the criteria already identified; namely: prejudice filters. These filters have been identified by the literature study and are tested by means of a prototype implementation that uses a specific scenario in order to test two simulation case studies. / Dissertation (MSc)--University of Pretoria, 2008. / Computer Science / unrestricted

El tema principal de esta tesis es el desarrollo de técnicas de actualización de precondicionadores para resolver sistemas lineales de gran tamaño y dispersos Ax=b mediante el uso de métodos iterativos de Krylov. Se consideran dos tipos interesantes de problemas. En el primero se estudia la solución iterativa de sistemas lineales no singulares y antisimétricos, donde la matriz de coeficientes A tiene parte antisimétrica de rango bajo o puede aproximarse bien con una matriz antisimétrica de rango bajo. Sistemas como este surgen de la discretización de PDEs con ciertas condiciones de frontera de Neumann, la discretización de ecuaciones integrales y métodos de puntos interiores, por ejemplo, el problema de Bratu y la ecuación integral de Love. El segundo tipo de sistemas lineales considerados son problemas de mínimos cuadrados (LS) que se resuelven considerando la solución del sistema equivalente de ecuaciones normales. Concretamente, consideramos la solución de problemas LS modificados y de rango incompleto. Por problema LS modificado se entiende que el conjunto de ecuaciones lineales se actualiza con alguna información nueva, se agrega una nueva variable o, por el contrario, se elimina alguna información o variable del conjunto. En los problemas LS de rango deficiente, la matriz de coeficientes no tiene rango completo, lo que dificulta el cálculo de una factorización incompleta de las ecuaciones normales. Los problemas LS surgen en muchas aplicaciones a gran escala de la ciencia y la ingeniería como, por ejemplo, redes neuronales, programación lineal, sismología de exploración o procesamiento de imágenes. Los precondicionadores directos para métodos iterativos usados habitualmente son las factorizaciones incompletas LU, o de Cholesky cuando la matriz es simétrica definida positiva. La principal contribución de esta tesis es el desarrollo de técnicas de actualización de precondicionadores. Básicamente, el método consiste en el cálculo de una descomposición incompleta para un sistema lineal aumentado equivalente, que se utiliza como precondicionador para el problema original. El estudio teórico y los resultados numéricos presentados en esta tesis muestran el rendimiento de la técnica de precondicionamiento propuesta y su competitividad en comparación con otros métodos disponibles en la literatura para calcular precondicionadores para los problemas estudiados. / The main topic of this thesis is updating preconditioners for solving large sparse linear systems Ax=b by using Krylov iterative methods. Two interesting types of problems are considered. In the first one is studied the iterative solution of non-singular, non-symmetric linear systems where the coefficient matrix A has a skew-symmetric part of low-rank or can be well approximated with a skew-symmetric low-rank matrix. Systems like this arise from the discretization of PDEs with certain Neumann boundary conditions, the discretization of integral equations as well as path following methods, for example, the Bratu problem and the Love's integral equation. The second type of linear systems considered are least squares (LS) problems that are solved by considering the solution of the equivalent normal equations system. More precisely, we consider the solution of modified and rank deficient LS problems. By modified LS problem, it is understood that the set of linear relations is updated with some new information, a new variable is added or, contrarily, some information or variable is removed from the set. Rank deficient LS problems are characterized by a coefficient matrix that has not full rank, which makes difficult the computation of an incomplete factorization of the normal equations. LS problems arise in many large-scale applications of the science and engineering as for instance neural networks, linear programming, exploration seismology or image processing. Usually, incomplete LU or incomplete Cholesky factorization are used as preconditioners for iterative methods. The main contribution of this thesis is the development of a technique for updating preconditioners by bordering. It consists in the computation of an approximate decomposition for an equivalent augmented linear system, that is used as preconditioner for the original problem. The theoretical study and the results of the numerical experiments presented in this thesis show the performance of the preconditioner technique proposed and its competitiveness compared with other methods available in the literature for computing preconditioners for the problems studied. / El tema principal d'esta tesi és actualitzar precondicionadors per a resoldre sistemes lineals grans i buits Ax=b per mitjà de l'ús de mètodes iteratius de Krylov. Es consideren dos tipus interessants de problemes. En el primer s'estudia la solució iterativa de sistemes lineals no singulars i antisimètrics, on la matriu de coeficients A té una part antisimètrica de baix rang, o bé pot aproximar-se amb una matriu antisimètrica de baix rang. Sistemes com este sorgixen de la discretització de PDEs amb certes condicions de frontera de Neumann, la discretització d'equacions integrals i mètodes de punts interiors, per exemple, el problema de Bratu i l'equació integral de Love. El segon tipus de sistemes lineals considerats, són problemes de mínims quadrats (LS) que es resolen considerant la solució del sistema equivalent d'equacions normals. Concretament, considerem la solució de problemes de LS modificats i de rang incomplet. Per problema LS modificat, s'entén que el conjunt d'equacions lineals s'actualitza amb alguna informació nova, s'agrega una nova variable o, al contrari, s'elimina alguna informació o variable del conjunt. En els problemes LS de rang deficient, la matriu de coeficients no té rang complet, la qual cosa dificultata el calcul d'una factorització incompleta de les equacions normals. Els problemes LS sorgixen en moltes aplicacions a gran escala de la ciència i l'enginyeria com, per exemple, xarxes neuronals, programació lineal, sismologia d'exploració o processament d'imatges. Els precondicionadors directes per a mètodes iteratius utilitzats més a sovint són les factoritzacions incompletes tipus ILU, o la factorització incompleta de Cholesky quan la matriu és simètrica definida positiva. La principal contribució d'esta tesi és el desenvolupament de tècniques d'actualització de precondicionadors. Bàsicament, el mètode consistix en el càlcul d'una descomposició incompleta per a un sistema lineal augmentat equivalent, que s'utilitza com a precondicionador pel problema original. L'estudi teòric i els resultats numèrics presentats en esta tesi mostren el rendiment de la tècnica de precondicionament proposta i la seua competitivitat en comparació amb altres mètodes disponibles en la literatura per a calcular precondicionadors per als problemes considerats. / Guerrero Flores, DJ. (2018). On Updating Preconditioners for the Iterative Solution of Linear Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/104923 / TESIS

abstract: With the increased demand for genetically modified T-cells in treating hematological malignancies, the need for an optimized measurement policy within the current good manufacturing practices for better quality control has grown greatly. There are several steps involved in manufacturing gene therapy. These steps are for the autologous-type gene therapy, in chronological order, are harvesting T-cells from the patient, activation of the cells (thawing the cryogenically frozen cells after transport to manufacturing center), viral vector transduction, Chimeric Antigen Receptor (CAR) attachment during T-cell expansion, then infusion into patient. The need for improved measurement heuristics within the transduction and expansion portions of the manufacturing process has reached an all-time high because of the costly nature of manufacturing the product, the high cycle time (approximately 14-28 days from activation to infusion), and the risk for external contamination during manufacturing that negatively impacts patients post infusion (such as illness and death). The main objective of this work is to investigate and improve measurement policies on the basis of quality control in the transduction/expansion bio-manufacturing processes. More specifically, this study addresses the issue of measuring yield within the transduction/expansion phases of gene therapy. To do so, it was decided to model the process as a Markov Decision Process where the decisions being made are optimally chosen to create an overall optimal measurement policy; for a set of predefined parameters. / Dissertation/Thesis / Masters Thesis Industrial Engineering 2020

This master's thesis analyzes annotation server algorithms for searching and updating annotation fragments. The annotation server is a part of the project Decipher. Analyzed algorithms are improved and replaced by newly designed algorithms in this project. A part of this project also designs a new algorithm for measuring how much is an annotation affected after updating the document.

Collaboration is one of the most important topics regarding the evolution of the World Wide Web and thus also for the Web of Data. In scenarios of distributed collaboration on datasets it is necessary to provide support for multiple different versions of datasets to exist simultaneously, while also providing support for merging diverged datasets. In this paper we present an approach that uses SPARQL 1.1 in combination with the version control system Git, that creates commits for all changes applied to an RDF dataset containing multiple named graphs. Further the operations provided by Git are used to distribute the commits among collaborators and merge diverged versions of the dataset. We show the advantages of (public) Git repositories for RDF datasets and how this represents a way to collaborate on RDF data and consume it. With SPARQL 1.1 and Git in combination, users are given several opportunities to participate in the evolution of RDF data.